ParseContext.cpp

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Author : Mohan Maiya
Date : 2021-02-24 09:49:42
Hash : 550f2a3e
Message : Vulkan: Shader support for EXT_shader_framebuffer_fetch_non_coherent Translator can accept gl_LastFragData and 'inout' variable to gain access to framebuffer attachment data. The Vulkan translator replaces it with the SubpassInput type variable. Note that this works only for the noncoherent version of the extension. Bug: angleproject:5454 Test: *EXTShaderFramebufferFetchNoncoherent*.* Change-Id: I392f84ee3ad3eb9fbd09d0b7ff83731a9a3f33f6 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2598060 Reviewed-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Commit-Queue: Mohan Maiya <m.maiya@samsung.com>
src/compiler/translator/ParseContext.cpp
//
// Copyright 2002 The ANGLE Project Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
//

#include "compiler/translator/ParseContext.h"

#include <stdarg.h>
#include <stdio.h>

#include "common/mathutil.h"
#include "compiler/preprocessor/SourceLocation.h"
#include "compiler/translator/Declarator.h"
#include "compiler/translator/ParseContext_interm.h"
#include "compiler/translator/StaticType.h"
#include "compiler/translator/ValidateGlobalInitializer.h"
#include "compiler/translator/ValidateSwitch.h"
#include "compiler/translator/glslang.h"
#include "compiler/translator/tree_util/IntermNode_util.h"
#include "compiler/translator/util.h"

namespace sh
{

///////////////////////////////////////////////////////////////////////
//
// Sub- vector and matrix fields
//
////////////////////////////////////////////////////////////////////////

namespace
{

const int kWebGLMaxStructNesting = 4;

bool ContainsSampler(const TStructure *structType);

bool ContainsSampler(const TType &type)
{
    if (IsSampler(type.getBasicType()))
    {
        return true;
    }
    if (type.getBasicType() == EbtStruct)
    {
        return ContainsSampler(type.getStruct());
    }

    return false;
}

bool ContainsSampler(const TStructure *structType)
{
    for (const auto &field : structType->fields())
    {
        if (ContainsSampler(*field->type()))
            return true;
    }
    return false;
}

// Get a token from an image argument to use as an error message token.
const char *GetImageArgumentToken(TIntermTyped *imageNode)
{
    ASSERT(IsImage(imageNode->getBasicType()));
    while (imageNode->getAsBinaryNode() &&
           (imageNode->getAsBinaryNode()->getOp() == EOpIndexIndirect ||
            imageNode->getAsBinaryNode()->getOp() == EOpIndexDirect))
    {
        imageNode = imageNode->getAsBinaryNode()->getLeft();
    }
    TIntermSymbol *imageSymbol = imageNode->getAsSymbolNode();
    if (imageSymbol)
    {
        return imageSymbol->getName().data();
    }
    return "image";
}

bool CanSetDefaultPrecisionOnType(const TPublicType &type)
{
    if (!SupportsPrecision(type.getBasicType()))
    {
        return false;
    }
    if (type.getBasicType() == EbtUInt)
    {
        // ESSL 3.00.4 section 4.5.4
        return false;
    }
    if (type.isAggregate())
    {
        // Not allowed to set for aggregate types
        return false;
    }
    return true;
}

// Map input primitive types to input array sizes in a geometry shader.
GLuint GetGeometryShaderInputArraySize(TLayoutPrimitiveType primitiveType)
{
    switch (primitiveType)
    {
        case EptPoints:
            return 1u;
        case EptLines:
            return 2u;
        case EptTriangles:
            return 3u;
        case EptLinesAdjacency:
            return 4u;
        case EptTrianglesAdjacency:
            return 6u;
        default:
            UNREACHABLE();
            return 0u;
    }
}

bool IsBufferOrSharedVariable(TIntermTyped *var)
{
    if (var->isInterfaceBlock() || var->getQualifier() == EvqBuffer ||
        var->getQualifier() == EvqShared)
    {
        return true;
    }
    return false;
}

TIntermTyped *FindLValueBase(TIntermTyped *node)
{
    do
    {
        const TIntermBinary *binary = node->getAsBinaryNode();
        if (binary == nullptr)
        {
            return node;
        }

        TOperator op = binary->getOp();
        if (op != EOpIndexDirect && op != EOpIndexIndirect)
        {
            return static_cast<TIntermTyped *>(nullptr);
        }

        node = binary->getLeft();
    } while (true);
}

}  // namespace

// This tracks each binding point's current default offset for inheritance of subsequent
// variables using the same binding, and keeps offsets unique and non overlapping.
// See GLSL ES 3.1, section 4.4.6.
class TParseContext::AtomicCounterBindingState
{
  public:
    AtomicCounterBindingState() : mDefaultOffset(0) {}
    // Inserts a new span and returns -1 if overlapping, else returns the starting offset of
    // newly inserted span.
    int insertSpan(int start, size_t length)
    {
        gl::RangeI newSpan(start, start + static_cast<int>(length));
        for (const auto &span : mSpans)
        {
            if (newSpan.intersects(span))
            {
                return -1;
            }
        }
        mSpans.push_back(newSpan);
        mDefaultOffset = newSpan.high();
        return start;
    }
    // Inserts a new span starting from the default offset.
    int appendSpan(size_t length) { return insertSpan(mDefaultOffset, length); }
    void setDefaultOffset(int offset) { mDefaultOffset = offset; }

  private:
    int mDefaultOffset;
    std::vector<gl::RangeI> mSpans;
};

TParseContext::TParseContext(TSymbolTable &symt,
                             TExtensionBehavior &ext,
                             sh::GLenum type,
                             ShShaderSpec spec,
                             ShCompileOptions options,
                             bool checksPrecErrors,
                             TDiagnostics *diagnostics,
                             const ShBuiltInResources &resources,
                             ShShaderOutput outputType)
    : symbolTable(symt),
      mDeferredNonEmptyDeclarationErrorCheck(false),
      mShaderType(type),
      mShaderSpec(spec),
      mCompileOptions(options),
      mShaderVersion(100),
      mTreeRoot(nullptr),
      mLoopNestingLevel(0),
      mStructNestingLevel(0),
      mSwitchNestingLevel(0),
      mCurrentFunctionType(nullptr),
      mFunctionReturnsValue(false),
      mChecksPrecisionErrors(checksPrecErrors),
      mFragmentPrecisionHighOnESSL1(false),
      mEarlyFragmentTestsSpecified(false),
      mDefaultUniformMatrixPacking(EmpColumnMajor),
      mDefaultUniformBlockStorage(sh::IsWebGLBasedSpec(spec) ? EbsStd140 : EbsShared),
      mDefaultBufferMatrixPacking(EmpColumnMajor),
      mDefaultBufferBlockStorage(sh::IsWebGLBasedSpec(spec) ? EbsStd140 : EbsShared),
      mDiagnostics(diagnostics),
      mDirectiveHandler(ext,
                        *mDiagnostics,
                        mShaderVersion,
                        mShaderType,
                        resources.WEBGL_debug_shader_precision == 1),
      mPreprocessor(mDiagnostics, &mDirectiveHandler, angle::pp::PreprocessorSettings(spec)),
      mScanner(nullptr),
      mMinProgramTexelOffset(resources.MinProgramTexelOffset),
      mMaxProgramTexelOffset(resources.MaxProgramTexelOffset),
      mMinProgramTextureGatherOffset(resources.MinProgramTextureGatherOffset),
      mMaxProgramTextureGatherOffset(resources.MaxProgramTextureGatherOffset),
      mComputeShaderLocalSizeDeclared(false),
      mComputeShaderLocalSize(-1),
      mNumViews(-1),
      mMaxNumViews(resources.MaxViewsOVR),
      mMaxImageUnits(resources.MaxImageUnits),
      mMaxCombinedTextureImageUnits(resources.MaxCombinedTextureImageUnits),
      mMaxUniformLocations(resources.MaxUniformLocations),
      mMaxUniformBufferBindings(resources.MaxUniformBufferBindings),
      mMaxVertexAttribs(resources.MaxVertexAttribs),
      mMaxAtomicCounterBindings(resources.MaxAtomicCounterBindings),
      mMaxShaderStorageBufferBindings(resources.MaxShaderStorageBufferBindings),
      mDeclaringFunction(false),
      mGeometryShaderInputPrimitiveType(EptUndefined),
      mGeometryShaderOutputPrimitiveType(EptUndefined),
      mGeometryShaderInvocations(0),
      mGeometryShaderMaxVertices(-1),
      mMaxGeometryShaderInvocations(resources.MaxGeometryShaderInvocations),
      mMaxGeometryShaderMaxVertices(resources.MaxGeometryOutputVertices),
      mGeometryInputArraySize(0),
      mMaxPatchVertices(resources.MaxPatchVertices),
      mTessControlShaderOutputVertices(0),
      mTessEvaluationShaderInputPrimitiveType(EtetUndefined),
      mTessEvaluationShaderInputVertexSpacingType(EtetUndefined),
      mTessEvaluationShaderInputOrderingType(EtetUndefined),
      mTessEvaluationShaderInputPointType(EtetUndefined),
      mFunctionBodyNewScope(false),
      mOutputType(outputType)
{}

TParseContext::~TParseContext() {}

bool TParseContext::anyMultiviewExtensionAvailable()
{
    return isExtensionEnabled(TExtension::OVR_multiview) ||
           isExtensionEnabled(TExtension::OVR_multiview2);
}

bool TParseContext::parseVectorFields(const TSourceLoc &line,
                                      const ImmutableString &compString,
                                      int vecSize,
                                      TVector<int> *fieldOffsets)
{
    ASSERT(fieldOffsets);
    size_t fieldCount = compString.length();
    if (fieldCount > 4u)
    {
        error(line, "illegal vector field selection", compString);
        return false;
    }
    fieldOffsets->resize(fieldCount);

    enum
    {
        exyzw,
        ergba,
        estpq
    } fieldSet[4];

    for (unsigned int i = 0u; i < fieldOffsets->size(); ++i)
    {
        switch (compString[i])
        {
            case 'x':
                (*fieldOffsets)[i] = 0;
                fieldSet[i]        = exyzw;
                break;
            case 'r':
                (*fieldOffsets)[i] = 0;
                fieldSet[i]        = ergba;
                break;
            case 's':
                (*fieldOffsets)[i] = 0;
                fieldSet[i]        = estpq;
                break;
            case 'y':
                (*fieldOffsets)[i] = 1;
                fieldSet[i]        = exyzw;
                break;
            case 'g':
                (*fieldOffsets)[i] = 1;
                fieldSet[i]        = ergba;
                break;
            case 't':
                (*fieldOffsets)[i] = 1;
                fieldSet[i]        = estpq;
                break;
            case 'z':
                (*fieldOffsets)[i] = 2;
                fieldSet[i]        = exyzw;
                break;
            case 'b':
                (*fieldOffsets)[i] = 2;
                fieldSet[i]        = ergba;
                break;
            case 'p':
                (*fieldOffsets)[i] = 2;
                fieldSet[i]        = estpq;
                break;

            case 'w':
                (*fieldOffsets)[i] = 3;
                fieldSet[i]        = exyzw;
                break;
            case 'a':
                (*fieldOffsets)[i] = 3;
                fieldSet[i]        = ergba;
                break;
            case 'q':
                (*fieldOffsets)[i] = 3;
                fieldSet[i]        = estpq;
                break;
            default:
                error(line, "illegal vector field selection", compString);
                return false;
        }
    }

    for (unsigned int i = 0u; i < fieldOffsets->size(); ++i)
    {
        if ((*fieldOffsets)[i] >= vecSize)
        {
            error(line, "vector field selection out of range", compString);
            return false;
        }

        if (i > 0)
        {
            if (fieldSet[i] != fieldSet[i - 1])
            {
                error(line, "illegal - vector component fields not from the same set", compString);
                return false;
            }
        }
    }

    return true;
}

///////////////////////////////////////////////////////////////////////
//
// Errors
//
////////////////////////////////////////////////////////////////////////

//
// Used by flex/bison to output all syntax and parsing errors.
//
void TParseContext::error(const TSourceLoc &loc, const char *reason, const char *token)
{
    mDiagnostics->error(loc, reason, token);
}

void TParseContext::error(const TSourceLoc &loc, const char *reason, const ImmutableString &token)
{
    mDiagnostics->error(loc, reason, token.data());
}

void TParseContext::warning(const TSourceLoc &loc, const char *reason, const char *token)
{
    mDiagnostics->warning(loc, reason, token);
}

void TParseContext::outOfRangeError(bool isError,
                                    const TSourceLoc &loc,
                                    const char *reason,
                                    const char *token)
{
    if (isError)
    {
        error(loc, reason, token);
    }
    else
    {
        warning(loc, reason, token);
    }
}

//
// Same error message for all places assignments don't work.
//
void TParseContext::assignError(const TSourceLoc &line,
                                const char *op,
                                const TType &left,
                                const TType &right)
{
    TInfoSinkBase reasonStream;
    reasonStream << "cannot convert from '" << right << "' to '" << left << "'";
    error(line, reasonStream.c_str(), op);
}

//
// Same error message for all places unary operations don't work.
//
void TParseContext::unaryOpError(const TSourceLoc &line, const char *op, const TType &operand)
{
    TInfoSinkBase reasonStream;
    reasonStream << "wrong operand type - no operation '" << op
                 << "' exists that takes an operand of type " << operand
                 << " (or there is no acceptable conversion)";
    error(line, reasonStream.c_str(), op);
}

//
// Same error message for all binary operations don't work.
//
void TParseContext::binaryOpError(const TSourceLoc &line,
                                  const char *op,
                                  const TType &left,
                                  const TType &right)
{
    TInfoSinkBase reasonStream;
    reasonStream << "wrong operand types - no operation '" << op
                 << "' exists that takes a left-hand operand of type '" << left
                 << "' and a right operand of type '" << right
                 << "' (or there is no acceptable conversion)";
    error(line, reasonStream.c_str(), op);
}

void TParseContext::checkPrecisionSpecified(const TSourceLoc &line,
                                            TPrecision precision,
                                            TBasicType type)
{
    if (!mChecksPrecisionErrors)
        return;

    if (precision != EbpUndefined && !SupportsPrecision(type))
    {
        error(line, "illegal type for precision qualifier", getBasicString(type));
    }

    if (precision == EbpUndefined)
    {
        switch (type)
        {
            case EbtFloat:
                error(line, "No precision specified for (float)", "");
                return;
            case EbtInt:
            case EbtUInt:
                UNREACHABLE();  // there's always a predeclared qualifier
                error(line, "No precision specified (int)", "");
                return;
            default:
                if (IsOpaqueType(type))
                {
                    error(line, "No precision specified", getBasicString(type));
                    return;
                }
        }
    }
}

void TParseContext::markStaticReadIfSymbol(TIntermNode *node)
{
    TIntermSwizzle *swizzleNode = node->getAsSwizzleNode();
    if (swizzleNode)
    {
        markStaticReadIfSymbol(swizzleNode->getOperand());
        return;
    }
    TIntermBinary *binaryNode = node->getAsBinaryNode();
    if (binaryNode)
    {
        switch (binaryNode->getOp())
        {
            case EOpIndexDirect:
            case EOpIndexIndirect:
            case EOpIndexDirectStruct:
            case EOpIndexDirectInterfaceBlock:
                markStaticReadIfSymbol(binaryNode->getLeft());
                return;
            default:
                return;
        }
    }
    TIntermSymbol *symbolNode = node->getAsSymbolNode();
    if (symbolNode)
    {
        symbolTable.markStaticRead(symbolNode->variable());
    }
}

// Both test and if necessary, spit out an error, to see if the node is really
// an l-value that can be operated on this way.
bool TParseContext::checkCanBeLValue(const TSourceLoc &line, const char *op, TIntermTyped *node)
{
    TIntermSwizzle *swizzleNode = node->getAsSwizzleNode();
    if (swizzleNode)
    {
        bool ok = checkCanBeLValue(line, op, swizzleNode->getOperand());
        if (ok && swizzleNode->hasDuplicateOffsets())
        {
            error(line, " l-value of swizzle cannot have duplicate components", op);
            return false;
        }
        return ok;
    }

    TIntermBinary *binaryNode = node->getAsBinaryNode();
    if (binaryNode)
    {
        switch (binaryNode->getOp())
        {
            case EOpIndexDirect:
            case EOpIndexIndirect:
            case EOpIndexDirectStruct:
            case EOpIndexDirectInterfaceBlock:
                if (node->getMemoryQualifier().readonly)
                {
                    error(line, "can't modify a readonly variable", op);
                    return false;
                }
                return checkCanBeLValue(line, op, binaryNode->getLeft());
            default:
                break;
        }
        error(line, " l-value required", op);
        return false;
    }

    std::string message;
    switch (node->getQualifier())
    {
        case EvqConst:
            message = "can't modify a const";
            break;
        case EvqConstReadOnly:
            message = "can't modify a const";
            break;
        case EvqAttribute:
            message = "can't modify an attribute";
            break;
        case EvqFragmentIn:
        case EvqVertexIn:
        case EvqGeometryIn:
        case EvqTessControlIn:
        case EvqTessEvaluationIn:
        case EvqFlatIn:
        case EvqNoPerspectiveIn:
        case EvqSmoothIn:
        case EvqCentroidIn:
        case EvqSampleIn:
            message = "can't modify an input";
            break;
        case EvqUniform:
            message = "can't modify a uniform";
            break;
        case EvqVaryingIn:
            message = "can't modify a varying";
            break;
        case EvqFragCoord:
            message = "can't modify gl_FragCoord";
            break;
        case EvqFrontFacing:
            message = "can't modify gl_FrontFacing";
            break;
        case EvqHelperInvocation:
            message = "can't modify gl_HelperInvocation";
            break;
        case EvqPointCoord:
            message = "can't modify gl_PointCoord";
            break;
        case EvqNumWorkGroups:
            message = "can't modify gl_NumWorkGroups";
            break;
        case EvqWorkGroupSize:
            message = "can't modify gl_WorkGroupSize";
            break;
        case EvqWorkGroupID:
            message = "can't modify gl_WorkGroupID";
            break;
        case EvqLocalInvocationID:
            message = "can't modify gl_LocalInvocationID";
            break;
        case EvqGlobalInvocationID:
            message = "can't modify gl_GlobalInvocationID";
            break;
        case EvqLocalInvocationIndex:
            message = "can't modify gl_LocalInvocationIndex";
            break;
        case EvqViewIDOVR:
            message = "can't modify gl_ViewID_OVR";
            break;
        case EvqComputeIn:
            message = "can't modify work group size variable";
            break;
        case EvqPerVertexIn:
            message = "can't modify any member in gl_in";
            break;
        case EvqPrimitiveIDIn:
            message = "can't modify gl_PrimitiveIDIn";
            break;
        case EvqInvocationID:
            message = "can't modify gl_InvocationID";
            break;
        case EvqPrimitiveID:
            if (mShaderType == GL_FRAGMENT_SHADER)
            {
                message = "can't modify gl_PrimitiveID in a fragment shader";
            }
            break;
        case EvqLayer:
            if (mShaderType == GL_FRAGMENT_SHADER)
            {
                message = "can't modify gl_Layer in a fragment shader";
            }
            break;
        case EvqSampleID:
            message = "can't modify gl_SampleID";
            break;
        case EvqSampleMaskIn:
            message = "can't modify gl_SampleMaskIn";
            break;
        case EvqSamplePosition:
            message = "can't modify gl_SamplePosition";
            break;
        case EvqClipDistance:
            if (mShaderType == GL_FRAGMENT_SHADER)
            {
                message = "can't modify gl_ClipDistance in a fragment shader";
            }
            break;
        case EvqCullDistance:
            if (mShaderType == GL_FRAGMENT_SHADER)
            {
                message = "can't modify gl_CullDistance in a fragment shader";
            }
            break;
        default:
            //
            // Type that can't be written to?
            //
            if (node->getBasicType() == EbtVoid)
            {
                message = "can't modify void";
            }
            if (IsOpaqueType(node->getBasicType()))
            {
                message = "can't modify a variable with type ";
                message += getBasicString(node->getBasicType());
            }
            else if (node->getMemoryQualifier().readonly)
            {
                message = "can't modify a readonly variable";
            }
    }

    ASSERT(binaryNode == nullptr && swizzleNode == nullptr);
    TIntermSymbol *symNode = node->getAsSymbolNode();
    if (message.empty() && symNode != nullptr)
    {
        symbolTable.markStaticWrite(symNode->variable());
        return true;
    }

    std::stringstream reasonStream = sh::InitializeStream<std::stringstream>();
    reasonStream << "l-value required";
    if (!message.empty())
    {
        if (symNode)
        {
            // Symbol inside an expression can't be nameless.
            ASSERT(symNode->variable().symbolType() != SymbolType::Empty);
            const ImmutableString &symbol = symNode->getName();
            reasonStream << " (" << message << " \"" << symbol << "\")";
        }
        else
        {
            reasonStream << " (" << message << ")";
        }
    }
    std::string reason = reasonStream.str();
    error(line, reason.c_str(), op);

    return false;
}

// Both test, and if necessary spit out an error, to see if the node is really
// a constant.
void TParseContext::checkIsConst(TIntermTyped *node)
{
    if (node->getQualifier() != EvqConst)
    {
        error(node->getLine(), "constant expression required", "");
    }
}

// Both test, and if necessary spit out an error, to see if the node is really
// an integer.
void TParseContext::checkIsScalarInteger(TIntermTyped *node, const char *token)
{
    if (!node->isScalarInt())
    {
        error(node->getLine(), "integer expression required", token);
    }
}

// Both test, and if necessary spit out an error, to see if we are currently
// globally scoped.
bool TParseContext::checkIsAtGlobalLevel(const TSourceLoc &line, const char *token)
{
    if (!symbolTable.atGlobalLevel())
    {
        error(line, "only allowed at global scope", token);
        return false;
    }
    return true;
}

// ESSL 3.00.5 sections 3.8 and 3.9.
// If it starts "gl_" or contains two consecutive underscores, it's reserved.
// Also checks for "webgl_" and "_webgl_" reserved identifiers if parsing a webgl shader.
bool TParseContext::checkIsNotReserved(const TSourceLoc &line, const ImmutableString &identifier)
{
    static const char *reservedErrMsg = "reserved built-in name";
    if (identifier.beginsWith("gl_"))
    {
        error(line, reservedErrMsg, "gl_");
        return false;
    }
    if (sh::IsWebGLBasedSpec(mShaderSpec))
    {
        if (identifier.beginsWith("webgl_"))
        {
            error(line, reservedErrMsg, "webgl_");
            return false;
        }
        if (identifier.beginsWith("_webgl_"))
        {
            error(line, reservedErrMsg, "_webgl_");
            return false;
        }
    }
    if (identifier.contains("__"))
    {
        error(line,
              "identifiers containing two consecutive underscores (__) are reserved as "
              "possible future keywords",
              identifier);
        return false;
    }
    return true;
}

// Make sure the argument types are correct for constructing a specific type.
bool TParseContext::checkConstructorArguments(const TSourceLoc &line,
                                              const TIntermSequence &arguments,
                                              const TType &type)
{
    if (arguments.empty())
    {
        error(line, "constructor does not have any arguments", "constructor");
        return false;
    }

    for (TIntermNode *arg : arguments)
    {
        markStaticReadIfSymbol(arg);
        const TIntermTyped *argTyped = arg->getAsTyped();
        ASSERT(argTyped != nullptr);
        if (type.getBasicType() != EbtStruct && IsOpaqueType(argTyped->getBasicType()))
        {
            std::string reason("cannot convert a variable with type ");
            reason += getBasicString(argTyped->getBasicType());
            error(line, reason.c_str(), "constructor");
            return false;
        }
        else if (argTyped->getMemoryQualifier().writeonly)
        {
            error(line, "cannot convert a variable with writeonly", "constructor");
            return false;
        }
        if (argTyped->getBasicType() == EbtVoid)
        {
            error(line, "cannot convert a void", "constructor");
            return false;
        }
    }

    if (type.isArray())
    {
        // The size of an unsized constructor should already have been determined.
        ASSERT(!type.isUnsizedArray());
        if (static_cast<size_t>(type.getOutermostArraySize()) != arguments.size())
        {
            error(line, "array constructor needs one argument per array element", "constructor");
            return false;
        }
        // GLSL ES 3.00 section 5.4.4: Each argument must be the same type as the element type of
        // the array.
        for (TIntermNode *const &argNode : arguments)
        {
            const TType &argType = argNode->getAsTyped()->getType();
            if (mShaderVersion < 310 && argType.isArray())
            {
                error(line, "constructing from a non-dereferenced array", "constructor");
                return false;
            }
            if (!argType.isElementTypeOf(type))
            {
                error(line, "Array constructor argument has an incorrect type", "constructor");
                return false;
            }
        }
    }
    else if (type.getBasicType() == EbtStruct)
    {
        const TFieldList &fields = type.getStruct()->fields();
        if (fields.size() != arguments.size())
        {
            error(line,
                  "Number of constructor parameters does not match the number of structure fields",
                  "constructor");
            return false;
        }

        for (size_t i = 0; i < fields.size(); i++)
        {
            if (i >= arguments.size() ||
                arguments[i]->getAsTyped()->getType() != *fields[i]->type())
            {
                error(line, "Structure constructor arguments do not match structure fields",
                      "constructor");
                return false;
            }
        }
    }
    else
    {
        // We're constructing a scalar, vector, or matrix.

        // Note: It's okay to have too many components available, but not okay to have unused
        // arguments. 'full' will go to true when enough args have been seen. If we loop again,
        // there is an extra argument, so 'overFull' will become true.

        size_t size    = 0;
        bool full      = false;
        bool overFull  = false;
        bool matrixArg = false;
        for (TIntermNode *arg : arguments)
        {
            const TIntermTyped *argTyped = arg->getAsTyped();
            ASSERT(argTyped != nullptr);

            if (argTyped->getBasicType() == EbtStruct)
            {
                error(line, "a struct cannot be used as a constructor argument for this type",
                      "constructor");
                return false;
            }
            if (argTyped->getType().isArray())
            {
                error(line, "constructing from a non-dereferenced array", "constructor");
                return false;
            }
            if (argTyped->getType().isMatrix())
            {
                matrixArg = true;
            }

            size += argTyped->getType().getObjectSize();
            if (full)
            {
                overFull = true;
            }
            if (size >= type.getObjectSize())
            {
                full = true;
            }
        }

        if (type.isMatrix() && matrixArg)
        {
            if (arguments.size() != 1)
            {
                error(line, "constructing matrix from matrix can only take one argument",
                      "constructor");
                return false;
            }
        }
        else
        {
            if (size != 1 && size < type.getObjectSize())
            {
                error(line, "not enough data provided for construction", "constructor");
                return false;
            }
            if (overFull)
            {
                error(line, "too many arguments", "constructor");
                return false;
            }
        }
    }

    return true;
}

// This function checks to see if a void variable has been declared and raise an error message for
// such a case
//
// returns true in case of an error
//
bool TParseContext::checkIsNonVoid(const TSourceLoc &line,
                                   const ImmutableString &identifier,
                                   const TBasicType &type)
{
    if (type == EbtVoid)
    {
        error(line, "illegal use of type 'void'", identifier);
        return false;
    }

    return true;
}

// This function checks to see if the node (for the expression) contains a scalar boolean expression
// or not.
bool TParseContext::checkIsScalarBool(const TSourceLoc &line, const TIntermTyped *type)
{
    if (type->getBasicType() != EbtBool || !type->isScalar())
    {
        error(line, "boolean expression expected", "");
        return false;
    }
    return true;
}

// This function checks to see if the node (for the expression) contains a scalar boolean expression
// or not.
void TParseContext::checkIsScalarBool(const TSourceLoc &line, const TPublicType &pType)
{
    if (pType.getBasicType() != EbtBool || pType.isAggregate())
    {
        error(line, "boolean expression expected", "");
    }
}

bool TParseContext::checkIsNotOpaqueType(const TSourceLoc &line,
                                         const TTypeSpecifierNonArray &pType,
                                         const char *reason)
{
    if (pType.type == EbtStruct)
    {
        if (ContainsSampler(pType.userDef))
        {
            std::stringstream reasonStream = sh::InitializeStream<std::stringstream>();
            reasonStream << reason << " (structure contains a sampler)";
            std::string reasonStr = reasonStream.str();
            error(line, reasonStr.c_str(), getBasicString(pType.type));
            return false;
        }
        // only samplers need to be checked from structs, since other opaque types can't be struct
        // members.
        return true;
    }
    else if (IsOpaqueType(pType.type))
    {
        error(line, reason, getBasicString(pType.type));
        return false;
    }

    return true;
}

void TParseContext::checkDeclaratorLocationIsNotSpecified(const TSourceLoc &line,
                                                          const TPublicType &pType)
{
    if (pType.layoutQualifier.location != -1)
    {
        error(line, "location must only be specified for a single input or output variable",
              "location");
    }
}

void TParseContext::checkLocationIsNotSpecified(const TSourceLoc &location,
                                                const TLayoutQualifier &layoutQualifier)
{
    if (layoutQualifier.location != -1)
    {
        const char *errorMsg = "invalid layout qualifier: only valid on program inputs and outputs";
        if (mShaderVersion >= 310)
        {
            errorMsg =
                "invalid layout qualifier: only valid on shader inputs, outputs, and uniforms";
        }
        error(location, errorMsg, "location");
    }
}

void TParseContext::checkStd430IsForShaderStorageBlock(const TSourceLoc &location,
                                                       const TLayoutBlockStorage &blockStorage,
                                                       const TQualifier &qualifier)
{
    if (blockStorage == EbsStd430 && qualifier != EvqBuffer)
    {
        error(location, "The std430 layout is supported only for shader storage blocks.", "std430");
    }
}

void TParseContext::checkOutParameterIsNotOpaqueType(const TSourceLoc &line,
                                                     TQualifier qualifier,
                                                     const TType &type)
{
    ASSERT(qualifier == EvqOut || qualifier == EvqInOut);
    if (IsOpaqueType(type.getBasicType()))
    {
        error(line, "opaque types cannot be output parameters", type.getBasicString());
    }
}

// Do size checking for an array type's size.
unsigned int TParseContext::checkIsValidArraySize(const TSourceLoc &line, TIntermTyped *expr)
{
    TIntermConstantUnion *constant = expr->getAsConstantUnion();

    // ANGLE should be able to fold any EvqConst expressions resulting in an integer - but to be
    // safe against corner cases we still check for constant folding. Some interpretations of the
    // spec have allowed constant expressions with side effects - like array length() method on a
    // non-constant array.
    if (expr->getQualifier() != EvqConst || constant == nullptr || !constant->isScalarInt())
    {
        error(line, "array size must be a constant integer expression", "");
        return 1u;
    }

    unsigned int size = 0u;

    if (constant->getBasicType() == EbtUInt)
    {
        size = constant->getUConst(0);
    }
    else
    {
        int signedSize = constant->getIConst(0);

        if (signedSize < 0)
        {
            error(line, "array size must be non-negative", "");
            return 1u;
        }

        size = static_cast<unsigned int>(signedSize);
    }

    if (size == 0u)
    {
        error(line, "array size must be greater than zero", "");
        return 1u;
    }

    if (IsOutputHLSL(getOutputType()))
    {
        // The size of arrays is restricted here to prevent issues further down the
        // compiler/translator/driver stack. Shader Model 5 generation hardware is limited to
        // 4096 registers so this should be reasonable even for aggressively optimizable code.
        const unsigned int sizeLimit = 65536;

        if (size > sizeLimit)
        {
            error(line, "array size too large", "");
            return 1u;
        }
    }

    return size;
}

// See if this qualifier can be an array.
bool TParseContext::checkIsValidQualifierForArray(const TSourceLoc &line,
                                                  const TPublicType &elementQualifier)
{
    if ((elementQualifier.qualifier == EvqAttribute) ||
        (elementQualifier.qualifier == EvqVertexIn) ||
        (elementQualifier.qualifier == EvqConst && mShaderVersion < 300))
    {
        error(line, "cannot declare arrays of this qualifier",
              TType(elementQualifier).getQualifierString());
        return false;
    }

    return true;
}

// See if this element type can be formed into an array.
bool TParseContext::checkArrayElementIsNotArray(const TSourceLoc &line,
                                                const TPublicType &elementType)
{
    if (mShaderVersion < 310 && elementType.isArray())
    {
        TInfoSinkBase typeString;
        typeString << TType(elementType);
        error(line, "cannot declare arrays of arrays", typeString.c_str());
        return false;
    }
    return true;
}

// Check for array-of-arrays being used as non-allowed shader inputs/outputs.
bool TParseContext::checkArrayOfArraysInOut(const TSourceLoc &line,
                                            const TPublicType &elementType,
                                            const TType &arrayType)
{
    if (arrayType.isArrayOfArrays())
    {
        if (elementType.qualifier == EvqVertexOut)
        {
            error(line, "vertex shader output cannot be an array of arrays",
                  TType(elementType).getQualifierString());
            return false;
        }
        if (elementType.qualifier == EvqFragmentIn)
        {
            error(line, "fragment shader input cannot be an array of arrays",
                  TType(elementType).getQualifierString());
            return false;
        }
        if (elementType.qualifier == EvqFragmentOut || elementType.qualifier == EvqFragmentInOut)
        {
            error(line, "fragment shader output cannot be an array of arrays",
                  TType(elementType).getQualifierString());
            return false;
        }
    }
    return true;
}

// Check if this qualified element type can be formed into an array. This is only called when array
// brackets are associated with an identifier in a declaration, like this:
//   float a[2];
// Similar checks are done in addFullySpecifiedType for array declarations where the array brackets
// are associated with the type, like this:
//   float[2] a;
bool TParseContext::checkIsValidTypeAndQualifierForArray(const TSourceLoc &indexLocation,
                                                         const TPublicType &elementType)
{
    if (!checkArrayElementIsNotArray(indexLocation, elementType))
    {
        return false;
    }
    // In ESSL1.00 shaders, structs cannot be varying (section 4.3.5). This is checked elsewhere.
    // In ESSL3.00 shaders, struct inputs/outputs are allowed but not arrays of structs (section
    // 4.3.4).
    // Geometry shader requires each user-defined input be declared as arrays or inside input
    // blocks declared as arrays (GL_EXT_geometry_shader section 11.1gs.4.3). For the purposes of
    // interface matching, such variables and blocks are treated as though they were not declared
    // as arrays (GL_EXT_geometry_shader section 7.4.1).
    if (mShaderVersion >= 300 && elementType.getBasicType() == EbtStruct &&
        sh::IsVarying(elementType.qualifier) &&
        !IsGeometryShaderInput(mShaderType, elementType.qualifier) &&
        !IsTessellationControlShaderInput(mShaderType, elementType.qualifier) &&
        !IsTessellationEvaluationShaderInput(mShaderType, elementType.qualifier) &&
        !IsTessellationControlShaderOutput(mShaderType, elementType.qualifier))
    {
        TInfoSinkBase typeString;
        typeString << TType(elementType);
        error(indexLocation, "cannot declare arrays of structs of this qualifier",
              typeString.c_str());
        return false;
    }
    return checkIsValidQualifierForArray(indexLocation, elementType);
}

// Enforce non-initializer type/qualifier rules.
void TParseContext::checkCanBeDeclaredWithoutInitializer(const TSourceLoc &line,
                                                         const ImmutableString &identifier,
                                                         TType *type)
{
    ASSERT(type != nullptr);
    if (type->getQualifier() == EvqConst)
    {
        // Make the qualifier make sense.
        type->setQualifier(EvqTemporary);

        // Generate informative error messages for ESSL1.
        // In ESSL3 arrays and structures containing arrays can be constant.
        if (mShaderVersion < 300 && type->isStructureContainingArrays())
        {
            error(line,
                  "structures containing arrays may not be declared constant since they cannot be "
                  "initialized",
                  identifier);
        }
        else
        {
            error(line, "variables with qualifier 'const' must be initialized", identifier);
        }
    }
    checkIsNotUnsizedArray(line, "implicitly sized arrays need to be initialized", identifier,
                           type);
}

// Do some simple checks that are shared between all variable declarations,
// and update the symbol table.
//
// Returns true if declaring the variable succeeded.
//
bool TParseContext::declareVariable(const TSourceLoc &line,
                                    const ImmutableString &identifier,
                                    const TType *type,
                                    TVariable **variable)
{
    ASSERT((*variable) == nullptr);

    (*variable) = new TVariable(&symbolTable, identifier, type, SymbolType::UserDefined);

    ASSERT(type->getLayoutQualifier().index == -1 ||
           (isExtensionEnabled(TExtension::EXT_blend_func_extended) &&
            mShaderType == GL_FRAGMENT_SHADER && mShaderVersion >= 300));
    if (type->getQualifier() == EvqFragmentOut)
    {
        if (type->getLayoutQualifier().index != -1 && type->getLayoutQualifier().location == -1)
        {
            error(line,
                  "If index layout qualifier is specified for a fragment output, location must "
                  "also be specified.",
                  "index");
            return false;
        }
    }
    else
    {
        checkIndexIsNotSpecified(line, type->getLayoutQualifier().index);
    }

    if (!((identifier.beginsWith("gl_LastFragData") || type->getQualifier() == EvqFragmentInOut) &&
          (isExtensionEnabled(TExtension::EXT_shader_framebuffer_fetch) ||
           isExtensionEnabled(TExtension::EXT_shader_framebuffer_fetch_non_coherent))))
    {
        checkNoncoherentIsNotSpecified(line, type->getLayoutQualifier().noncoherent);
    }
    else if (isExtensionEnabled(TExtension::EXT_shader_framebuffer_fetch_non_coherent) &&
             !isExtensionEnabled(TExtension::EXT_shader_framebuffer_fetch))
    {
        checkNoncoherentIsSpecified(line, type->getLayoutQualifier().noncoherent);
    }

    checkBindingIsValid(line, *type);

    bool needsReservedCheck = true;

    // gl_LastFragData may be redeclared with a new precision qualifier
    if (type->isArray() && identifier.beginsWith("gl_LastFragData"))
    {
        const TVariable *maxDrawBuffers = static_cast<const TVariable *>(
            symbolTable.findBuiltIn(ImmutableString("gl_MaxDrawBuffers"), mShaderVersion));
        if (type->isArrayOfArrays())
        {
            error(line, "redeclaration of gl_LastFragData as an array of arrays", identifier);
            return false;
        }
        else if (static_cast<int>(type->getOutermostArraySize()) ==
                 maxDrawBuffers->getConstPointer()->getIConst())
        {
            if (const TSymbol *builtInSymbol = symbolTable.findBuiltIn(identifier, mShaderVersion))
            {
                needsReservedCheck = !checkCanUseExtension(line, builtInSymbol->extension());
            }
        }
        else
        {
            error(line, "redeclaration of gl_LastFragData with size != gl_MaxDrawBuffers",
                  identifier);
            return false;
        }
    }
    else if (type->isArray() && identifier == "gl_ClipDistance")
    {
        // gl_ClipDistance can be redeclared with smaller size than gl_MaxClipDistances
        const TVariable *maxClipDistances = static_cast<const TVariable *>(
            symbolTable.findBuiltIn(ImmutableString("gl_MaxClipDistances"), mShaderVersion));
        if (!maxClipDistances)
        {
            // Unsupported extension
            needsReservedCheck = true;
        }
        else if (type->isArrayOfArrays())
        {
            error(line, "redeclaration of gl_ClipDistance as an array of arrays", identifier);
            return false;
        }
        else if (static_cast<int>(type->getOutermostArraySize()) <=
                 maxClipDistances->getConstPointer()->getIConst())
        {
            if (const TSymbol *builtInSymbol = symbolTable.findBuiltIn(identifier, mShaderVersion))
            {
                needsReservedCheck = !checkCanUseExtension(line, builtInSymbol->extension());
            }
        }
        else
        {
            error(line, "redeclaration of gl_ClipDistance with size > gl_MaxClipDistances",
                  identifier);
            return false;
        }
    }
    else if (type->isArray() && identifier == "gl_CullDistance")
    {
        // gl_CullDistance can be redeclared with smaller size than gl_MaxCullDistances
        const TVariable *maxCullDistances = static_cast<const TVariable *>(
            symbolTable.findBuiltIn(ImmutableString("gl_MaxCullDistances"), mShaderVersion));
        if (!maxCullDistances)
        {
            // Unsupported extension
            needsReservedCheck = true;
        }
        else if (type->isArrayOfArrays())
        {
            error(line, "redeclaration of gl_CullDistance as an array of arrays", identifier);
            return false;
        }
        else if (static_cast<int>(type->getOutermostArraySize()) <=
                 maxCullDistances->getConstPointer()->getIConst())
        {
            if (const TSymbol *builtInSymbol = symbolTable.findBuiltIn(identifier, mShaderVersion))
            {
                needsReservedCheck = !checkCanUseExtension(line, builtInSymbol->extension());
            }
        }
        else
        {
            error(line, "redeclaration of gl_CullDistance with size > gl_MaxCullDistances",
                  identifier);
            return false;
        }
    }

    if (needsReservedCheck && !checkIsNotReserved(line, identifier))
        return false;

    if (!symbolTable.declare(*variable))
    {
        error(line, "redefinition", identifier);
        return false;
    }

    if (!checkIsNonVoid(line, identifier, type->getBasicType()))
        return false;

    return true;
}

void TParseContext::checkIsParameterQualifierValid(
    const TSourceLoc &line,
    const TTypeQualifierBuilder &typeQualifierBuilder,
    TType *type)
{
    // The only parameter qualifiers a parameter can have are in, out, inout or const.
    TTypeQualifier typeQualifier = typeQualifierBuilder.getParameterTypeQualifier(mDiagnostics);

    if (typeQualifier.qualifier == EvqOut || typeQualifier.qualifier == EvqInOut)
    {
        checkOutParameterIsNotOpaqueType(line, typeQualifier.qualifier, *type);
    }

    if (!IsImage(type->getBasicType()))
    {
        checkMemoryQualifierIsNotSpecified(typeQualifier.memoryQualifier, line);
    }
    else
    {
        type->setMemoryQualifier(typeQualifier.memoryQualifier);
    }

    type->setQualifier(typeQualifier.qualifier);

    if (typeQualifier.precision != EbpUndefined)
    {
        type->setPrecision(typeQualifier.precision);
    }
}

template <size_t size>
bool TParseContext::checkCanUseOneOfExtensions(const TSourceLoc &line,
                                               const std::array<TExtension, size> &extensions)
{
    ASSERT(!extensions.empty());
    const TExtensionBehavior &extBehavior = extensionBehavior();

    bool canUseWithWarning    = false;
    bool canUseWithoutWarning = false;

    const char *errorMsgString   = "";
    TExtension errorMsgExtension = TExtension::UNDEFINED;

    for (TExtension extension : extensions)
    {
        auto extIter = extBehavior.find(extension);
        if (canUseWithWarning)
        {
            // We already have an extension that we can use, but with a warning.
            // See if we can use the alternative extension without a warning.
            if (extIter == extBehavior.end())
            {
                continue;
            }
            if (extIter->second == EBhEnable || extIter->second == EBhRequire)
            {
                canUseWithoutWarning = true;
                break;
            }
            continue;
        }
        if (extIter == extBehavior.end())
        {
            errorMsgString    = "extension is not supported";
            errorMsgExtension = extension;
        }
        else if (extIter->second == EBhUndefined || extIter->second == EBhDisable)
        {
            errorMsgString    = "extension is disabled";
            errorMsgExtension = extension;
        }
        else if (extIter->second == EBhWarn)
        {
            errorMsgExtension = extension;
            canUseWithWarning = true;
        }
        else
        {
            ASSERT(extIter->second == EBhEnable || extIter->second == EBhRequire);
            canUseWithoutWarning = true;
            break;
        }
    }

    if (canUseWithoutWarning)
    {
        return true;
    }
    if (canUseWithWarning)
    {
        warning(line, "extension is being used", GetExtensionNameString(errorMsgExtension));
        return true;
    }
    error(line, errorMsgString, GetExtensionNameString(errorMsgExtension));
    return false;
}

template bool TParseContext::checkCanUseOneOfExtensions(
    const TSourceLoc &line,
    const std::array<TExtension, 1> &extensions);
template bool TParseContext::checkCanUseOneOfExtensions(
    const TSourceLoc &line,
    const std::array<TExtension, 2> &extensions);
template bool TParseContext::checkCanUseOneOfExtensions(
    const TSourceLoc &line,
    const std::array<TExtension, 3> &extensions);

bool TParseContext::checkCanUseExtension(const TSourceLoc &line, TExtension extension)
{
    ASSERT(extension != TExtension::UNDEFINED);
    return checkCanUseOneOfExtensions(line, std::array<TExtension, 1u>{{extension}});
}

// ESSL 3.00.6 section 4.8 Empty Declarations: "The combinations of qualifiers that cause
// compile-time or link-time errors are the same whether or not the declaration is empty".
// This function implements all the checks that are done on qualifiers regardless of if the
// declaration is empty.
void TParseContext::declarationQualifierErrorCheck(const sh::TQualifier qualifier,
                                                   const sh::TLayoutQualifier &layoutQualifier,
                                                   const TSourceLoc &location)
{
    if (qualifier == EvqShared && !layoutQualifier.isEmpty())
    {
        error(location, "Shared memory declarations cannot have layout specified", "layout");
    }

    if (layoutQualifier.matrixPacking != EmpUnspecified)
    {
        error(location, "layout qualifier only valid for interface blocks",
              getMatrixPackingString(layoutQualifier.matrixPacking));
        return;
    }

    if (layoutQualifier.blockStorage != EbsUnspecified)
    {
        error(location, "layout qualifier only valid for interface blocks",
              getBlockStorageString(layoutQualifier.blockStorage));
        return;
    }

    if (qualifier == EvqFragmentOut)
    {
        if (layoutQualifier.location != -1 && layoutQualifier.yuv == true)
        {
            error(location, "invalid layout qualifier combination", "yuv");
            return;
        }
    }
    else
    {
        checkYuvIsNotSpecified(location, layoutQualifier.yuv);
    }

    if (qualifier != EvqFragmentIn)
    {
        checkEarlyFragmentTestsIsNotSpecified(location, layoutQualifier.earlyFragmentTests);
    }

    // If multiview extension is enabled, "in" qualifier is allowed in the vertex shader in previous
    // parsing steps. So it needs to be checked here.
    if (anyMultiviewExtensionAvailable() && mShaderVersion < 300 && qualifier == EvqVertexIn)
    {
        error(location, "storage qualifier supported in GLSL ES 3.00 and above only", "in");
    }

    bool canHaveLocation = qualifier == EvqVertexIn || qualifier == EvqFragmentOut;
    if (mShaderVersion >= 300 &&
        (isExtensionEnabled(TExtension::EXT_shader_framebuffer_fetch) ||
         isExtensionEnabled(TExtension::EXT_shader_framebuffer_fetch_non_coherent)))
    {
        // In the case of EXT_shader_framebuffer_fetch or EXT_shader_framebuffer_fetch_non_coherent
        // extension, the location of inout qualifier is used to set the input attachment index
        canHaveLocation = canHaveLocation || qualifier == EvqFragmentInOut;
    }
    if (mShaderVersion >= 310)
    {
        canHaveLocation = canHaveLocation || qualifier == EvqUniform || IsVarying(qualifier);
        // We're not checking whether the uniform location is in range here since that depends on
        // the type of the variable.
        // The type can only be fully determined for non-empty declarations.
    }
    if (!canHaveLocation)
    {
        checkLocationIsNotSpecified(location, layoutQualifier);
    }
}

void TParseContext::atomicCounterQualifierErrorCheck(const TPublicType &publicType,
                                                     const TSourceLoc &location)
{
    if (publicType.precision != EbpHigh)
    {
        error(location, "Can only be highp", "atomic counter");
    }
    // dEQP enforces compile error if location is specified. See uniform_location.test.
    if (publicType.layoutQualifier.location != -1)
    {
        error(location, "location must not be set for atomic_uint", "layout");
    }
    if (publicType.layoutQualifier.binding == -1)
    {
        error(location, "no binding specified", "atomic counter");
    }
}

void TParseContext::emptyDeclarationErrorCheck(const TType &type, const TSourceLoc &location)
{
    if (type.isUnsizedArray())
    {
        // ESSL3 spec section 4.1.9: Array declaration which leaves the size unspecified is an
        // error. It is assumed that this applies to empty declarations as well.
        error(location, "empty array declaration needs to specify a size", "");
    }

    if (type.getQualifier() != EvqFragmentOut)
    {
        checkIndexIsNotSpecified(location, type.getLayoutQualifier().index);
    }
}

// These checks are done for all declarations that are non-empty. They're done for non-empty
// declarations starting a declarator list, and declarators that follow an empty declaration.
void TParseContext::nonEmptyDeclarationErrorCheck(const TPublicType &publicType,
                                                  const TSourceLoc &identifierLocation)
{
    switch (publicType.qualifier)
    {
        case EvqVaryingIn:
        case EvqVaryingOut:
        case EvqAttribute:
        case EvqVertexIn:
        case EvqFragmentOut:
        case EvqFragmentInOut:
        case EvqComputeIn:
            if (publicType.getBasicType() == EbtStruct)
            {
                error(identifierLocation, "cannot be used with a structure",
                      getQualifierString(publicType.qualifier));
                return;
            }
            break;
        case EvqBuffer:
            if (publicType.getBasicType() != EbtInterfaceBlock)
            {
                error(identifierLocation,
                      "cannot declare buffer variables at global scope(outside a block)",
                      getQualifierString(publicType.qualifier));
                return;
            }
            break;
        default:
            break;
    }
    std::string reason(getBasicString(publicType.getBasicType()));
    reason += "s must be uniform";
    if (publicType.qualifier != EvqUniform &&
        !checkIsNotOpaqueType(identifierLocation, publicType.typeSpecifierNonArray, reason.c_str()))
    {
        return;
    }

    if ((publicType.qualifier != EvqTemporary && publicType.qualifier != EvqGlobal &&
         publicType.qualifier != EvqConst) &&
        publicType.getBasicType() == EbtYuvCscStandardEXT)
    {
        error(identifierLocation, "cannot be used with a yuvCscStandardEXT",
              getQualifierString(publicType.qualifier));
        return;
    }

    if (mShaderVersion >= 310 && publicType.qualifier == EvqUniform)
    {
        // Valid uniform declarations can't be unsized arrays since uniforms can't be initialized.
        // But invalid shaders may still reach here with an unsized array declaration.
        TType type(publicType);
        if (!type.isUnsizedArray())
        {
            checkUniformLocationInRange(identifierLocation, type.getLocationCount(),
                                        publicType.layoutQualifier);
        }
    }

    if (mShaderVersion >= 300 && publicType.qualifier == EvqVertexIn)
    {
        // Valid vertex input declarations can't be unsized arrays since they can't be initialized.
        // But invalid shaders may still reach here with an unsized array declaration.
        TType type(publicType);
        if (!type.isUnsizedArray())
        {
            checkAttributeLocationInRange(identifierLocation, type.getLocationCount(),
                                          publicType.layoutQualifier);
        }
    }

    // check for layout qualifier issues
    const TLayoutQualifier layoutQualifier = publicType.layoutQualifier;

    if (IsImage(publicType.getBasicType()))
    {

        switch (layoutQualifier.imageInternalFormat)
        {
            case EiifRGBA32F:
            case EiifRGBA16F:
            case EiifR32F:
            case EiifRGBA8:
            case EiifRGBA8_SNORM:
                if (!IsFloatImage(publicType.getBasicType()))
                {
                    error(identifierLocation,
                          "internal image format requires a floating image type",
                          getBasicString(publicType.getBasicType()));
                    return;
                }
                break;
            case EiifRGBA32I:
            case EiifRGBA16I:
            case EiifRGBA8I:
            case EiifR32I:
                if (!IsIntegerImage(publicType.getBasicType()))
                {
                    error(identifierLocation,
                          "internal image format requires an integer image type",
                          getBasicString(publicType.getBasicType()));
                    return;
                }
                break;
            case EiifRGBA32UI:
            case EiifRGBA16UI:
            case EiifRGBA8UI:
            case EiifR32UI:
                if (!IsUnsignedImage(publicType.getBasicType()))
                {
                    error(identifierLocation,
                          "internal image format requires an unsigned image type",
                          getBasicString(publicType.getBasicType()));
                    return;
                }
                break;
            case EiifUnspecified:
                error(identifierLocation, "layout qualifier", "No image internal format specified");
                return;
            default:
                error(identifierLocation, "layout qualifier", "unrecognized token");
                return;
        }

        // GLSL ES 3.10 Revision 4, 4.9 Memory Access Qualifiers
        switch (layoutQualifier.imageInternalFormat)
        {
            case EiifR32F:
            case EiifR32I:
            case EiifR32UI:
                break;
            default:
                if (!publicType.memoryQualifier.readonly && !publicType.memoryQualifier.writeonly)
                {
                    error(identifierLocation, "layout qualifier",
                          "Except for images with the r32f, r32i and r32ui format qualifiers, "
                          "image variables must be qualified readonly and/or writeonly");
                    return;
                }
                break;
        }
    }
    else
    {
        checkInternalFormatIsNotSpecified(identifierLocation, layoutQualifier.imageInternalFormat);
        checkMemoryQualifierIsNotSpecified(publicType.memoryQualifier, identifierLocation);
    }

    if (IsAtomicCounter(publicType.getBasicType()))
    {
        atomicCounterQualifierErrorCheck(publicType, identifierLocation);
    }
    else
    {
        checkOffsetIsNotSpecified(identifierLocation, layoutQualifier.offset);
    }
}

void TParseContext::checkBindingIsValid(const TSourceLoc &identifierLocation, const TType &type)
{
    TLayoutQualifier layoutQualifier = type.getLayoutQualifier();
    // Note that the ESSL 3.10 section 4.4.5 is not particularly clear on how the binding qualifier
    // on arrays of arrays should be handled. We interpret the spec so that the binding value is
    // incremented for each element of the innermost nested arrays. This is in line with how arrays
    // of arrays of blocks are specified to behave in GLSL 4.50 and a conservative interpretation
    // when it comes to which shaders are accepted by the compiler.
    int arrayTotalElementCount = type.getArraySizeProduct();
    if (IsImage(type.getBasicType()))
    {
        checkImageBindingIsValid(identifierLocation, layoutQualifier.binding,
                                 arrayTotalElementCount);
    }
    else if (IsSampler(type.getBasicType()))
    {
        checkSamplerBindingIsValid(identifierLocation, layoutQualifier.binding,
                                   arrayTotalElementCount);
    }
    else if (IsAtomicCounter(type.getBasicType()))
    {
        checkAtomicCounterBindingIsValid(identifierLocation, layoutQualifier.binding);
    }
    else
    {
        ASSERT(!IsOpaqueType(type.getBasicType()));
        checkBindingIsNotSpecified(identifierLocation, layoutQualifier.binding);
    }
}

void TParseContext::checkCanUseLayoutQualifier(const TSourceLoc &location)
{
    constexpr std::array<TExtension, 2u> extensions{
        {TExtension::EXT_shader_framebuffer_fetch,
         TExtension::EXT_shader_framebuffer_fetch_non_coherent}};
    if (getShaderVersion() < 300 && !checkCanUseOneOfExtensions(location, extensions))
    {
        error(location, "qualifier supported in GLSL ES 3.00 and above only", "layout");
    }
}

bool TParseContext::checkLayoutQualifierSupported(const TSourceLoc &location,
                                                  const ImmutableString &layoutQualifierName,
                                                  int versionRequired)
{

    if (mShaderVersion < versionRequired)
    {
        error(location, "invalid layout qualifier: not supported", layoutQualifierName);
        return false;
    }
    return true;
}

bool TParseContext::checkWorkGroupSizeIsNotSpecified(const TSourceLoc &location,
                                                     const TLayoutQualifier &layoutQualifier)
{
    const sh::WorkGroupSize &localSize = layoutQualifier.localSize;
    for (size_t i = 0u; i < localSize.size(); ++i)
    {
        if (localSize[i] != -1)
        {
            error(location,
                  "invalid layout qualifier: only valid when used with 'in' in a compute shader "
                  "global layout declaration",
                  getWorkGroupSizeString(i));
            return false;
        }
    }

    return true;
}

void TParseContext::checkInternalFormatIsNotSpecified(const TSourceLoc &location,
                                                      TLayoutImageInternalFormat internalFormat)
{
    if (internalFormat != EiifUnspecified)
    {
        error(location, "invalid layout qualifier: only valid when used with images",
              getImageInternalFormatString(internalFormat));
    }
}

void TParseContext::checkIndexIsNotSpecified(const TSourceLoc &location, int index)
{
    if (index != -1)
    {
        error(location,
              "invalid layout qualifier: only valid when used with a fragment shader output in "
              "ESSL version >= 3.00 and EXT_blend_func_extended is enabled",
              "index");
    }
}

void TParseContext::checkBindingIsNotSpecified(const TSourceLoc &location, int binding)
{
    if (binding != -1)
    {
        error(location,
              "invalid layout qualifier: only valid when used with opaque types or blocks",
              "binding");
    }
}

void TParseContext::checkOffsetIsNotSpecified(const TSourceLoc &location, int offset)
{
    if (offset != -1)
    {
        error(location, "invalid layout qualifier: only valid when used with atomic counters",
              "offset");
    }
}

void TParseContext::checkImageBindingIsValid(const TSourceLoc &location,
                                             int binding,
                                             int arrayTotalElementCount)
{
    // Expects arraySize to be 1 when setting binding for only a single variable.
    if (binding >= 0 && binding + arrayTotalElementCount > mMaxImageUnits)
    {
        error(location, "image binding greater than gl_MaxImageUnits", "binding");
    }
}

void TParseContext::checkSamplerBindingIsValid(const TSourceLoc &location,
                                               int binding,
                                               int arrayTotalElementCount)
{
    // Expects arraySize to be 1 when setting binding for only a single variable.
    if (binding >= 0 && binding + arrayTotalElementCount > mMaxCombinedTextureImageUnits)
    {
        error(location, "sampler binding greater than maximum texture units", "binding");
    }
}

void TParseContext::checkBlockBindingIsValid(const TSourceLoc &location,
                                             const TQualifier &qualifier,
                                             int binding,
                                             int arraySize)
{
    int size = (arraySize == 0 ? 1 : arraySize);
    if (qualifier == EvqUniform)
    {
        if (binding + size > mMaxUniformBufferBindings)
        {
            error(location, "uniform block binding greater than MAX_UNIFORM_BUFFER_BINDINGS",
                  "binding");
        }
    }
    else if (qualifier == EvqBuffer)
    {
        if (binding + size > mMaxShaderStorageBufferBindings)
        {
            error(location,
                  "shader storage block binding greater than MAX_SHADER_STORAGE_BUFFER_BINDINGS",
                  "binding");
        }
    }
}
void TParseContext::checkAtomicCounterBindingIsValid(const TSourceLoc &location, int binding)
{
    if (binding >= mMaxAtomicCounterBindings)
    {
        error(location, "atomic counter binding greater than gl_MaxAtomicCounterBindings",
              "binding");
    }
}

void TParseContext::checkUniformLocationInRange(const TSourceLoc &location,
                                                int objectLocationCount,
                                                const TLayoutQualifier &layoutQualifier)
{
    int loc = layoutQualifier.location;
    if (loc >= 0)  // Shader-specified location
    {
        if (loc >= mMaxUniformLocations || objectLocationCount > mMaxUniformLocations ||
            static_cast<unsigned int>(loc) + static_cast<unsigned int>(objectLocationCount) >
                static_cast<unsigned int>(mMaxUniformLocations))
        {
            error(location, "Uniform location out of range", "location");
        }
    }
}

void TParseContext::checkAttributeLocationInRange(const TSourceLoc &location,
                                                  int objectLocationCount,
                                                  const TLayoutQualifier &layoutQualifier)
{
    int loc = layoutQualifier.location;
    if (loc >= 0)  // Shader-specified location
    {
        if (loc >= mMaxVertexAttribs || objectLocationCount > mMaxVertexAttribs ||
            static_cast<unsigned int>(loc) + static_cast<unsigned int>(objectLocationCount) >
                static_cast<unsigned int>(mMaxVertexAttribs))
        {
            error(location, "Attribute location out of range", "location");
        }
    }
}

void TParseContext::checkYuvIsNotSpecified(const TSourceLoc &location, bool yuv)
{
    if (yuv != false)
    {
        error(location, "invalid layout qualifier: only valid on program outputs", "yuv");
    }
}

void TParseContext::checkEarlyFragmentTestsIsNotSpecified(const TSourceLoc &location,
                                                          bool earlyFragmentTests)
{
    if (earlyFragmentTests != false)
    {
        error(location,
              "invalid layout qualifier: only valid when used with 'in' in a fragment shader",
              "early_fragment_tests");
    }
}

void TParseContext::checkNoncoherentIsSpecified(const TSourceLoc &location, bool noncoherent)
{
    if (noncoherent == false)
    {
        error(location,
              "'noncoherent' qualifier must be used when "
              "GL_EXT_shader_framebuffer_fetch_non_coherent extension is used",
              "noncoherent");
    }
}

void TParseContext::checkNoncoherentIsNotSpecified(const TSourceLoc &location, bool noncoherent)
{
    if (noncoherent != false)
    {
        error(location,
              "invalid layout qualifier: only valid when used with 'gl_LastFragData' or the "
              "variable decorated with 'inout' in a fragment shader",
              "noncoherent");
    }
}

void TParseContext::functionCallRValueLValueErrorCheck(const TFunction *fnCandidate,
                                                       TIntermAggregate *fnCall)
{
    for (size_t i = 0; i < fnCandidate->getParamCount(); ++i)
    {
        TQualifier qual        = fnCandidate->getParam(i)->getType().getQualifier();
        TIntermTyped *argument = (*(fnCall->getSequence()))[i]->getAsTyped();
        bool argumentIsRead = (IsQualifierUnspecified(qual) || qual == EvqIn || qual == EvqInOut ||
                               qual == EvqConstReadOnly);
        if (argumentIsRead)
        {
            markStaticReadIfSymbol(argument);
            if (!IsImage(argument->getBasicType()))
            {
                if (argument->getMemoryQualifier().writeonly)
                {
                    error(argument->getLine(),
                          "Writeonly value cannot be passed for 'in' or 'inout' parameters.",
                          fnCall->functionName());
                    return;
                }
            }
        }
        if (qual == EvqOut || qual == EvqInOut)
        {
            if (!checkCanBeLValue(argument->getLine(), "assign", argument))
            {
                error(argument->getLine(),
                      "Constant value cannot be passed for 'out' or 'inout' parameters.",
                      fnCall->functionName());
                return;
            }
        }
    }
}

void TParseContext::checkInvariantVariableQualifier(bool invariant,
                                                    const TQualifier qualifier,
                                                    const TSourceLoc &invariantLocation)
{
    if (!invariant)
        return;

    if (mShaderVersion < 300)
    {
        // input variables in the fragment shader can be also qualified as invariant
        if (!sh::CanBeInvariantESSL1(qualifier))
        {
            error(invariantLocation, "Cannot be qualified as invariant.", "invariant");
        }
    }
    else
    {
        if (!sh::CanBeInvariantESSL3OrGreater(qualifier))
        {
            error(invariantLocation, "Cannot be qualified as invariant.", "invariant");
        }
    }
}

bool TParseContext::isExtensionEnabled(TExtension extension) const
{
    return IsExtensionEnabled(extensionBehavior(), extension);
}

void TParseContext::handleExtensionDirective(const TSourceLoc &loc,
                                             const char *extName,
                                             const char *behavior)
{
    angle::pp::SourceLocation srcLoc;
    srcLoc.file = loc.first_file;
    srcLoc.line = loc.first_line;
    mDirectiveHandler.handleExtension(srcLoc, extName, behavior);
}

void TParseContext::handlePragmaDirective(const TSourceLoc &loc,
                                          const char *name,
                                          const char *value,
                                          bool stdgl)
{
    angle::pp::SourceLocation srcLoc;
    srcLoc.file = loc.first_file;
    srcLoc.line = loc.first_line;
    mDirectiveHandler.handlePragma(srcLoc, name, value, stdgl);
}

sh::WorkGroupSize TParseContext::getComputeShaderLocalSize() const
{
    sh::WorkGroupSize result(-1);
    for (size_t i = 0u; i < result.size(); ++i)
    {
        if (mComputeShaderLocalSizeDeclared && mComputeShaderLocalSize[i] == -1)
        {
            result[i] = 1;
        }
        else
        {
            result[i] = mComputeShaderLocalSize[i];
        }
    }
    return result;
}

TIntermConstantUnion *TParseContext::addScalarLiteral(const TConstantUnion *constantUnion,
                                                      const TSourceLoc &line)
{
    TIntermConstantUnion *node = new TIntermConstantUnion(
        constantUnion, TType(constantUnion->getType(), EbpUndefined, EvqConst));
    node->setLine(line);
    return node;
}

/////////////////////////////////////////////////////////////////////////////////
//
// Non-Errors.
//
/////////////////////////////////////////////////////////////////////////////////

const TVariable *TParseContext::getNamedVariable(const TSourceLoc &location,
                                                 const ImmutableString &name,
                                                 const TSymbol *symbol)
{
    if (!symbol)
    {
        error(location, "undeclared identifier", name);
        return nullptr;
    }

    if (!symbol->isVariable())
    {
        error(location, "variable expected", name);
        return nullptr;
    }

    const TVariable *variable = static_cast<const TVariable *>(symbol);

    if (variable->extension() != TExtension::UNDEFINED)
    {
        checkCanUseExtension(location, variable->extension());
    }

    // GLSL ES 3.1 Revision 4, 7.1.3 Compute Shader Special Variables
    if (getShaderType() == GL_COMPUTE_SHADER && !mComputeShaderLocalSizeDeclared &&
        variable->getType().getQualifier() == EvqWorkGroupSize)
    {
        error(location,
              "It is an error to use gl_WorkGroupSize before declaring the local group size",
              "gl_WorkGroupSize");
    }

    // If EXT_shader_framebuffer_fetch_non_coherent is used, gl_LastFragData should be decorated
    // with 'layout(noncoherent)' EXT_shader_framebuffer_fetch_non_coherent spec: "Unless the
    // GL_EXT_shader_framebuffer_fetch extension  has been enabled in addition, it's an error to use
    // gl_LastFragData if it hasn't been explicitly redeclared with layout(noncoherent)."
    if (isExtensionEnabled(TExtension::EXT_shader_framebuffer_fetch_non_coherent) &&
        !isExtensionEnabled(TExtension::EXT_shader_framebuffer_fetch) &&
        variable->getType().getQualifier() == EvqLastFragData)
    {
        checkNoncoherentIsSpecified(location, variable->getType().getLayoutQualifier().noncoherent);
    }
    return variable;
}

TIntermTyped *TParseContext::parseVariableIdentifier(const TSourceLoc &location,
                                                     const ImmutableString &name,
                                                     const TSymbol *symbol)
{
    const TVariable *variable = getNamedVariable(location, name, symbol);

    if (!variable)
    {
        TIntermTyped *node = CreateZeroNode(TType(EbtFloat, EbpHigh, EvqConst));
        node->setLine(location);
        return node;
    }

    const TType &variableType = variable->getType();
    TIntermTyped *node        = nullptr;

    if (variable->getConstPointer() && variableType.canReplaceWithConstantUnion())
    {
        const TConstantUnion *constArray = variable->getConstPointer();
        node                             = new TIntermConstantUnion(constArray, variableType);
    }
    else if (variableType.getQualifier() == EvqWorkGroupSize && mComputeShaderLocalSizeDeclared)
    {
        // gl_WorkGroupSize can be used to size arrays according to the ESSL 3.10.4 spec, so it
        // needs to be added to the AST as a constant and not as a symbol.
        sh::WorkGroupSize workGroupSize = getComputeShaderLocalSize();
        TConstantUnion *constArray      = new TConstantUnion[3];
        for (size_t i = 0; i < 3; ++i)
        {
            constArray[i].setUConst(static_cast<unsigned int>(workGroupSize[i]));
        }

        ASSERT(variableType.getBasicType() == EbtUInt);
        ASSERT(variableType.getObjectSize() == 3);

        TType type(variableType);
        type.setQualifier(EvqConst);
        node = new TIntermConstantUnion(constArray, type);
    }
    else if ((mGeometryShaderInputPrimitiveType != EptUndefined) &&
             (variableType.getQualifier() == EvqPerVertexIn))
    {
        ASSERT(symbolTable.getGlInVariableWithArraySize() != nullptr);
        node = new TIntermSymbol(symbolTable.getGlInVariableWithArraySize());
    }
    else
    {
        node = new TIntermSymbol(variable);
    }
    ASSERT(node != nullptr);
    node->setLine(location);
    return node;
}

// Initializers show up in several places in the grammar.  Have one set of
// code to handle them here.
//
// Returns true on success.
bool TParseContext::executeInitializer(const TSourceLoc &line,
                                       const ImmutableString &identifier,
                                       TType *type,
                                       TIntermTyped *initializer,
                                       TIntermBinary **initNode)
{
    ASSERT(initNode != nullptr);
    ASSERT(*initNode == nullptr);

    if (type->isUnsizedArray())
    {
        // In case initializer is not an array or type has more dimensions than initializer, this
        // will default to setting array sizes to 1. We have not checked yet whether the initializer
        // actually is an array or not. Having a non-array initializer for an unsized array will
        // result in an error later, so we don't generate an error message here.
        type->sizeUnsizedArrays(initializer->getType().getArraySizes());
    }

    const TQualifier qualifier = type->getQualifier();

    bool constError = false;
    if (qualifier == EvqConst)
    {
        if (EvqConst != initializer->getType().getQualifier())
        {
            TInfoSinkBase reasonStream;
            reasonStream << "assigning non-constant to '" << *type << "'";
            error(line, reasonStream.c_str(), "=");

            // We're still going to declare the variable to avoid extra error messages.
            type->setQualifier(EvqTemporary);
            constError = true;
        }
    }

    TVariable *variable = nullptr;
    if (!declareVariable(line, identifier, type, &variable))
    {
        return false;
    }

    if (constError)
    {
        return false;
    }

    bool nonConstGlobalInitializers =
        IsExtensionEnabled(mDirectiveHandler.extensionBehavior(),
                           TExtension::EXT_shader_non_constant_global_initializers);
    bool globalInitWarning = false;
    if (symbolTable.atGlobalLevel() &&
        !ValidateGlobalInitializer(initializer, mShaderVersion, sh::IsWebGLBasedSpec(mShaderSpec),
                                   nonConstGlobalInitializers, &globalInitWarning))
    {
        // Error message does not completely match behavior with ESSL 1.00, but
        // we want to steer developers towards only using constant expressions.
        error(line, "global variable initializers must be constant expressions", "=");
        return false;
    }
    if (globalInitWarning)
    {
        warning(
            line,
            "global variable initializers should be constant expressions "
            "(uniforms and globals are allowed in global initializers for legacy compatibility)",
            "=");
    }

    // identifier must be of type constant, a global, or a temporary
    if ((qualifier != EvqTemporary) && (qualifier != EvqGlobal) && (qualifier != EvqConst))
    {
        error(line, " cannot initialize this type of qualifier ",
              variable->getType().getQualifierString());
        return false;
    }

    TIntermSymbol *intermSymbol = new TIntermSymbol(variable);
    intermSymbol->setLine(line);

    if (!binaryOpCommonCheck(EOpInitialize, intermSymbol, initializer, line))
    {
        assignError(line, "=", variable->getType(), initializer->getType());
        return false;
    }

    if (qualifier == EvqConst)
    {
        // Save the constant folded value to the variable if possible.
        const TConstantUnion *constArray = initializer->getConstantValue();
        if (constArray)
        {
            variable->shareConstPointer(constArray);
            if (initializer->getType().canReplaceWithConstantUnion())
            {
                ASSERT(*initNode == nullptr);
                return true;
            }
        }
    }

    *initNode = new TIntermBinary(EOpInitialize, intermSymbol, initializer);
    markStaticReadIfSymbol(initializer);
    (*initNode)->setLine(line);
    return true;
}

TIntermNode *TParseContext::addConditionInitializer(const TPublicType &pType,
                                                    const ImmutableString &identifier,
                                                    TIntermTyped *initializer,
                                                    const TSourceLoc &loc)
{
    checkIsScalarBool(loc, pType);
    TIntermBinary *initNode = nullptr;
    TType *type             = new TType(pType);
    if (executeInitializer(loc, identifier, type, initializer, &initNode))
    {
        // The initializer is valid. The init condition needs to have a node - either the
        // initializer node, or a constant node in case the initialized variable is const and won't
        // be recorded in the AST.
        if (initNode == nullptr)
        {
            return initializer;
        }
        else
        {
            TIntermDeclaration *declaration = new TIntermDeclaration();
            declaration->appendDeclarator(initNode);
            return declaration;
        }
    }
    return nullptr;
}

TIntermNode *TParseContext::addLoop(TLoopType type,
                                    TIntermNode *init,
                                    TIntermNode *cond,
                                    TIntermTyped *expr,
                                    TIntermNode *body,
                                    const TSourceLoc &line)
{
    TIntermNode *node       = nullptr;
    TIntermTyped *typedCond = nullptr;
    if (cond)
    {
        markStaticReadIfSymbol(cond);
        typedCond = cond->getAsTyped();
    }
    if (expr)
    {
        markStaticReadIfSymbol(expr);
    }
    // In case the loop body was not parsed as a block and contains a statement that simply refers
    // to a variable, we need to mark it as statically used.
    if (body)
    {
        markStaticReadIfSymbol(body);
    }
    if (cond == nullptr || typedCond)
    {
        if (type == ELoopDoWhile)
        {
            checkIsScalarBool(line, typedCond);
        }
        // In the case of other loops, it was checked before that the condition is a scalar boolean.
        ASSERT(mDiagnostics->numErrors() > 0 || typedCond == nullptr ||
               (typedCond->getBasicType() == EbtBool && !typedCond->isArray() &&
                !typedCond->isVector()));

        node = new TIntermLoop(type, init, typedCond, expr, EnsureBlock(body));
        node->setLine(line);
        return node;
    }

    ASSERT(type != ELoopDoWhile);

    TIntermDeclaration *declaration = cond->getAsDeclarationNode();
    ASSERT(declaration);
    TIntermBinary *declarator = declaration->getSequence()->front()->getAsBinaryNode();
    ASSERT(declarator->getLeft()->getAsSymbolNode());

    // The condition is a declaration. In the AST representation we don't support declarations as
    // loop conditions. Wrap the loop to a block that declares the condition variable and contains
    // the loop.
    TIntermBlock *block = new TIntermBlock();

    TIntermDeclaration *declareCondition = new TIntermDeclaration();
    declareCondition->appendDeclarator(declarator->getLeft()->deepCopy());
    block->appendStatement(declareCondition);

    TIntermBinary *conditionInit = new TIntermBinary(EOpAssign, declarator->getLeft()->deepCopy(),
                                                     declarator->getRight()->deepCopy());
    TIntermLoop *loop = new TIntermLoop(type, init, conditionInit, expr, EnsureBlock(body));
    block->appendStatement(loop);
    loop->setLine(line);
    block->setLine(line);
    return block;
}

TIntermNode *TParseContext::addIfElse(TIntermTyped *cond,
                                      TIntermNodePair code,
                                      const TSourceLoc &loc)
{
    bool isScalarBool = checkIsScalarBool(loc, cond);
    // In case the conditional statements were not parsed as blocks and contain a statement that
    // simply refers to a variable, we need to mark them as statically used.
    if (code.node1)
    {
        markStaticReadIfSymbol(code.node1);
    }
    if (code.node2)
    {
        markStaticReadIfSymbol(code.node2);
    }

    // For compile time constant conditions, prune the code now.
    if (isScalarBool && cond->getAsConstantUnion())
    {
        if (cond->getAsConstantUnion()->getBConst(0) == true)
        {
            return EnsureBlock(code.node1);
        }
        else
        {
            return EnsureBlock(code.node2);
        }
    }

    TIntermIfElse *node = new TIntermIfElse(cond, EnsureBlock(code.node1), EnsureBlock(code.node2));
    markStaticReadIfSymbol(cond);
    node->setLine(loc);

    return node;
}

void TParseContext::addFullySpecifiedType(TPublicType *typeSpecifier)
{
    checkPrecisionSpecified(typeSpecifier->getLine(), typeSpecifier->precision,
                            typeSpecifier->getBasicType());

    if (mShaderVersion < 300 && typeSpecifier->isArray())
    {
        error(typeSpecifier->getLine(), "not supported", "first-class array");
        typeSpecifier->clearArrayness();
    }
}

TPublicType TParseContext::addFullySpecifiedType(const TTypeQualifierBuilder &typeQualifierBuilder,
                                                 const TPublicType &typeSpecifier)
{
    TTypeQualifier typeQualifier = typeQualifierBuilder.getVariableTypeQualifier(mDiagnostics);

    TPublicType returnType     = typeSpecifier;
    returnType.qualifier       = typeQualifier.qualifier;
    returnType.invariant       = typeQualifier.invariant;
    returnType.precise         = typeQualifier.precise;
    returnType.layoutQualifier = typeQualifier.layoutQualifier;
    returnType.memoryQualifier = typeQualifier.memoryQualifier;
    returnType.precision       = typeSpecifier.precision;

    if (typeQualifier.precision != EbpUndefined)
    {
        returnType.precision = typeQualifier.precision;
    }

    checkPrecisionSpecified(typeSpecifier.getLine(), returnType.precision,
                            typeSpecifier.getBasicType());

    checkInvariantVariableQualifier(returnType.invariant, returnType.qualifier,
                                    typeSpecifier.getLine());

    checkWorkGroupSizeIsNotSpecified(typeSpecifier.getLine(), returnType.layoutQualifier);

    checkEarlyFragmentTestsIsNotSpecified(typeSpecifier.getLine(),
                                          returnType.layoutQualifier.earlyFragmentTests);

    if (mShaderVersion < 300)
    {
        if (typeSpecifier.isArray())
        {
            error(typeSpecifier.getLine(), "not supported", "first-class array");
            returnType.clearArrayness();
        }

        if (returnType.qualifier == EvqAttribute &&
            (typeSpecifier.getBasicType() == EbtBool || typeSpecifier.getBasicType() == EbtInt))
        {
            error(typeSpecifier.getLine(), "cannot be bool or int",
                  getQualifierString(returnType.qualifier));
        }

        if ((returnType.qualifier == EvqVaryingIn || returnType.qualifier == EvqVaryingOut) &&
            (typeSpecifier.getBasicType() == EbtBool || typeSpecifier.getBasicType() == EbtInt))
        {
            error(typeSpecifier.getLine(), "cannot be bool or int",
                  getQualifierString(returnType.qualifier));
        }
    }
    else
    {
        if (!returnType.layoutQualifier.isEmpty())
        {
            checkIsAtGlobalLevel(typeSpecifier.getLine(), "layout");
        }
        if (sh::IsVarying(returnType.qualifier) || returnType.qualifier == EvqVertexIn ||
            returnType.qualifier == EvqFragmentOut || returnType.qualifier == EvqFragmentInOut)
        {
            checkInputOutputTypeIsValidES3(returnType.qualifier, typeSpecifier,
                                           typeSpecifier.getLine());
        }
        if (returnType.qualifier == EvqComputeIn)
        {
            error(typeSpecifier.getLine(), "'in' can be only used to specify the local group size",
                  "in");
        }
    }

    return returnType;
}

void TParseContext::checkInputOutputTypeIsValidES3(const TQualifier qualifier,
                                                   const TPublicType &type,
                                                   const TSourceLoc &qualifierLocation)
{
    // An input/output variable can never be bool or a sampler. Samplers are checked elsewhere.
    if (type.getBasicType() == EbtBool)
    {
        error(qualifierLocation, "cannot be bool", getQualifierString(qualifier));
    }

    // Specific restrictions apply for vertex shader inputs and fragment shader outputs.
    switch (qualifier)
    {
        case EvqVertexIn:
            // ESSL 3.00 section 4.3.4
            if (type.isArray())
            {
                error(qualifierLocation, "cannot be array", getQualifierString(qualifier));
            }
            // Vertex inputs with a struct type are disallowed in nonEmptyDeclarationErrorCheck
            return;
        case EvqFragmentOut:
        case EvqFragmentInOut:
            // ESSL 3.00 section 4.3.6
            if (type.typeSpecifierNonArray.isMatrix())
            {
                error(qualifierLocation, "cannot be matrix", getQualifierString(qualifier));
            }
            // Fragment outputs with a struct type are disallowed in nonEmptyDeclarationErrorCheck
            return;
        default:
            break;
    }

    // Vertex shader outputs / fragment shader inputs have a different, slightly more lenient set of
    // restrictions.
    bool typeContainsIntegers =
        (type.getBasicType() == EbtInt || type.getBasicType() == EbtUInt ||
         type.isStructureContainingType(EbtInt) || type.isStructureContainingType(EbtUInt));
    bool extendedShaderTypes = mShaderVersion >= 320 ||
                               isExtensionEnabled(TExtension::EXT_geometry_shader) ||
                               isExtensionEnabled(TExtension::EXT_tessellation_shader);
    if (typeContainsIntegers && qualifier != EvqFlatIn && qualifier != EvqFlatOut &&
        (!extendedShaderTypes || mShaderType == GL_FRAGMENT_SHADER))
    {
        error(qualifierLocation, "must use 'flat' interpolation here",
              getQualifierString(qualifier));
    }

    if (type.getBasicType() == EbtStruct)
    {
        // ESSL 3.00 sections 4.3.4 and 4.3.6.
        // These restrictions are only implied by the ESSL 3.00 spec, but
        // the ESSL 3.10 spec lists these restrictions explicitly.
        if (type.isArray())
        {
            error(qualifierLocation, "cannot be an array of structures",
                  getQualifierString(qualifier));
        }
        if (type.isStructureContainingArrays())
        {
            error(qualifierLocation, "cannot be a structure containing an array",
                  getQualifierString(qualifier));
        }
        if (type.isStructureContainingType(EbtStruct))
        {
            error(qualifierLocation, "cannot be a structure containing a structure",
                  getQualifierString(qualifier));
        }
        if (type.isStructureContainingType(EbtBool))
        {
            error(qualifierLocation, "cannot be a structure containing a bool",
                  getQualifierString(qualifier));
        }
    }
}

void TParseContext::checkLocalVariableConstStorageQualifier(const TQualifierWrapperBase &qualifier)
{
    if (qualifier.getType() == QtStorage)
    {
        const TStorageQualifierWrapper &storageQualifier =
            static_cast<const TStorageQualifierWrapper &>(qualifier);
        if (!declaringFunction() && storageQualifier.getQualifier() != EvqConst &&
            !symbolTable.atGlobalLevel())
        {
            error(storageQualifier.getLine(),
                  "Local variables can only use the const storage qualifier.",
                  storageQualifier.getQualifierString());
        }
    }
}

void TParseContext::checkMemoryQualifierIsNotSpecified(const TMemoryQualifier &memoryQualifier,
                                                       const TSourceLoc &location)
{
    const std::string reason(
        "Only allowed with shader storage blocks, variables declared within shader storage blocks "
        "and variables declared as image types.");
    if (memoryQualifier.readonly)
    {
        error(location, reason.c_str(), "readonly");
    }
    if (memoryQualifier.writeonly)
    {
        error(location, reason.c_str(), "writeonly");
    }
    if (memoryQualifier.coherent)
    {
        error(location, reason.c_str(), "coherent");
    }
    if (memoryQualifier.restrictQualifier)
    {
        error(location, reason.c_str(), "restrict");
    }
    if (memoryQualifier.volatileQualifier)
    {
        error(location, reason.c_str(), "volatile");
    }
}

// Make sure there is no offset overlapping, and store the newly assigned offset to "type" in
// intermediate tree.
void TParseContext::checkAtomicCounterOffsetDoesNotOverlap(bool forceAppend,
                                                           const TSourceLoc &loc,
                                                           TType *type)
{
    const size_t size = type->isArray() ? kAtomicCounterArrayStride * type->getArraySizeProduct()
                                        : kAtomicCounterSize;
    TLayoutQualifier layoutQualifier = type->getLayoutQualifier();
    auto &bindingState               = mAtomicCounterBindingStates[layoutQualifier.binding];
    int offset;
    if (layoutQualifier.offset == -1 || forceAppend)
    {
        offset = bindingState.appendSpan(size);
    }
    else
    {
        offset = bindingState.insertSpan(layoutQualifier.offset, size);
    }
    if (offset == -1)
    {
        error(loc, "Offset overlapping", "atomic counter");
        return;
    }
    layoutQualifier.offset = offset;
    type->setLayoutQualifier(layoutQualifier);
}

void TParseContext::checkAtomicCounterOffsetAlignment(const TSourceLoc &location, const TType &type)
{
    TLayoutQualifier layoutQualifier = type.getLayoutQualifier();

    // OpenGL ES 3.1 Table 6.5, Atomic counter offset must be a multiple of 4
    if (layoutQualifier.offset % 4 != 0)
    {
        error(location, "Offset must be multiple of 4", "atomic counter");
    }
}

void TParseContext::checkGeometryShaderInputAndSetArraySize(const TSourceLoc &location,
                                                            const ImmutableString &token,
                                                            TType *type)
{
    if (IsGeometryShaderInput(mShaderType, type->getQualifier()))
    {
        if (type->isArray() && type->getOutermostArraySize() == 0u)
        {
            // Set size for the unsized geometry shader inputs if they are declared after a valid
            // input primitive declaration.
            if (mGeometryShaderInputPrimitiveType != EptUndefined)
            {
                ASSERT(symbolTable.getGlInVariableWithArraySize() != nullptr);
                type->sizeOutermostUnsizedArray(
                    symbolTable.getGlInVariableWithArraySize()->getType().getOutermostArraySize());
            }
            else
            {
                // [GLSL ES 3.2 SPEC Chapter 4.4.1.2]
                // An input can be declared without an array size if there is a previous layout
                // which specifies the size.
                error(location,
                      "Missing a valid input primitive declaration before declaring an unsized "
                      "array input",
                      token);
            }
        }
        else if (type->isArray())
        {
            setGeometryShaderInputArraySize(type->getOutermostArraySize(), location);
        }
        else
        {
            error(location, "Geometry shader input variable must be declared as an array", token);
        }
    }
}

void TParseContext::checkTessellationShaderUnsizedArraysAndSetSize(const TSourceLoc &location,
                                                                   const ImmutableString &token,
                                                                   TType *type)
{
    TQualifier qualifier = type->getQualifier();
    if (!IsTessellationControlShaderOutput(mShaderType, qualifier) &&
        !IsTessellationControlShaderInput(mShaderType, qualifier) &&
        !IsTessellationEvaluationShaderInput(mShaderType, qualifier))
    {
        return;
    }

    // Such variables must be declared as arrays or inside output blocks declared as arrays.
    if (!type->isArray())
    {
        error(location, "Tessellation interface variables must be declared as an array", token);
        return;
    }

    // If a size is specified, it must match the maximum patch size.
    unsigned int outermostSize = type->getOutermostArraySize();
    if (outermostSize == 0u)
    {
        switch (qualifier)
        {
            case EvqTessControlIn:
            case EvqTessEvaluationIn:
            case EvqFlatIn:
            case EvqCentroidIn:
            case EvqSmoothIn:
                // Declaring an array size is optional. If no size is specified, it will be taken
                // from the implementation-dependent maximum patch size (gl_MaxPatchVertices).
                ASSERT(mMaxPatchVertices > 0);
                type->sizeOutermostUnsizedArray(mMaxPatchVertices);
                break;
            case EvqTessControlOut:
            case EvqFlatOut:
            case EvqCentroidOut:
            case EvqSmoothOut:
                // Declaring an array size is optional. If no size is specified, it will be taken
                // from output patch size declared in the shader.
                type->sizeOutermostUnsizedArray(mTessControlShaderOutputVertices);
                break;
            default:
                UNREACHABLE();
                break;
        }
    }
    else
    {
        if (IsTessellationControlShaderInput(mShaderType, qualifier) ||
            IsTessellationEvaluationShaderInput(mShaderType, qualifier))
        {
            if (outermostSize != static_cast<unsigned int>(mMaxPatchVertices))
            {
                error(
                    location,
                    "If a size is specified for a tessellation control or evaluation user-defined "
                    "input variable, it must match the maximum patch size (gl_MaxPatchVertices).",
                    token);
            }
        }
        else if (IsTessellationControlShaderOutput(mShaderType, qualifier))
        {
            if (outermostSize != static_cast<unsigned int>(mTessControlShaderOutputVertices) &&
                mTessControlShaderOutputVertices != 0)
            {
                error(location,
                      "If a size is specified for a tessellation control user-defined per-vertex "
                      "output variable, it must match the the number of vertices in the output "
                      "patch.",
                      token);
            }
        }

        return;
    }
}

TIntermDeclaration *TParseContext::parseSingleDeclaration(
    TPublicType &publicType,
    const TSourceLoc &identifierOrTypeLocation,
    const ImmutableString &identifier)
{
    TType *type = new TType(publicType);
    if ((mCompileOptions & SH_FLATTEN_PRAGMA_STDGL_INVARIANT_ALL) != 0 &&
        mDirectiveHandler.pragma().stdgl.invariantAll)
    {
        TQualifier qualifier = type->getQualifier();

        // The directive handler has already taken care of rejecting invalid uses of this pragma
        // (for example, in ESSL 3.00 fragment shaders), so at this point, flatten it into all
        // affected variable declarations:
        //
        // 1. Built-in special variables which are inputs to the fragment shader. (These are handled
        // elsewhere, in TranslatorGLSL.)
        //
        // 2. Outputs from vertex shaders in ESSL 1.00 and 3.00 (EvqVaryingOut and EvqVertexOut). It
        // is actually less likely that there will be bugs in the handling of ESSL 3.00 shaders, but
        // the way this is currently implemented we have to enable this compiler option before
        // parsing the shader and determining the shading language version it uses. If this were
        // implemented as a post-pass, the workaround could be more targeted.
        if (qualifier == EvqVaryingOut || qualifier == EvqVertexOut)
        {
            type->setInvariant(true);
        }
    }

    checkGeometryShaderInputAndSetArraySize(identifierOrTypeLocation, identifier, type);
    checkTessellationShaderUnsizedArraysAndSetSize(identifierOrTypeLocation, identifier, type);

    declarationQualifierErrorCheck(publicType.qualifier, publicType.layoutQualifier,
                                   identifierOrTypeLocation);

    bool emptyDeclaration                  = (identifier == "");
    mDeferredNonEmptyDeclarationErrorCheck = emptyDeclaration;

    TIntermSymbol *symbol = nullptr;
    if (emptyDeclaration)
    {
        emptyDeclarationErrorCheck(*type, identifierOrTypeLocation);
        // In most cases we don't need to create a symbol node for an empty declaration.
        // But if the empty declaration is declaring a struct type, the symbol node will store that.
        if (type->getBasicType() == EbtStruct)
        {
            TVariable *emptyVariable =
                new TVariable(&symbolTable, kEmptyImmutableString, type, SymbolType::Empty);
            symbol = new TIntermSymbol(emptyVariable);
        }
        else if (IsAtomicCounter(publicType.getBasicType()))
        {
            setAtomicCounterBindingDefaultOffset(publicType, identifierOrTypeLocation);
        }
    }
    else
    {
        nonEmptyDeclarationErrorCheck(publicType, identifierOrTypeLocation);

        checkCanBeDeclaredWithoutInitializer(identifierOrTypeLocation, identifier, type);

        if (IsAtomicCounter(type->getBasicType()))
        {
            checkAtomicCounterOffsetDoesNotOverlap(false, identifierOrTypeLocation, type);

            checkAtomicCounterOffsetAlignment(identifierOrTypeLocation, *type);
        }

        TVariable *variable = nullptr;
        if (declareVariable(identifierOrTypeLocation, identifier, type, &variable))
        {
            symbol = new TIntermSymbol(variable);
        }
    }

    TIntermDeclaration *declaration = new TIntermDeclaration();
    declaration->setLine(identifierOrTypeLocation);
    if (symbol)
    {
        symbol->setLine(identifierOrTypeLocation);
        declaration->appendDeclarator(symbol);
    }
    return declaration;
}

TIntermDeclaration *TParseContext::parseSingleArrayDeclaration(
    TPublicType &elementType,
    const TSourceLoc &identifierLocation,
    const ImmutableString &identifier,
    const TSourceLoc &indexLocation,
    const TVector<unsigned int> &arraySizes)
{
    mDeferredNonEmptyDeclarationErrorCheck = false;

    declarationQualifierErrorCheck(elementType.qualifier, elementType.layoutQualifier,
                                   identifierLocation);

    nonEmptyDeclarationErrorCheck(elementType, identifierLocation);

    checkIsValidTypeAndQualifierForArray(indexLocation, elementType);

    TType *arrayType = new TType(elementType);
    arrayType->makeArrays(arraySizes);

    checkArrayOfArraysInOut(indexLocation, elementType, *arrayType);

    checkGeometryShaderInputAndSetArraySize(indexLocation, identifier, arrayType);
    checkTessellationShaderUnsizedArraysAndSetSize(indexLocation, identifier, arrayType);

    checkCanBeDeclaredWithoutInitializer(identifierLocation, identifier, arrayType);

    if (IsAtomicCounter(arrayType->getBasicType()))
    {
        checkAtomicCounterOffsetDoesNotOverlap(false, identifierLocation, arrayType);

        checkAtomicCounterOffsetAlignment(identifierLocation, *arrayType);
    }

    TIntermDeclaration *declaration = new TIntermDeclaration();
    declaration->setLine(identifierLocation);

    TVariable *variable = nullptr;
    if (declareVariable(identifierLocation, identifier, arrayType, &variable))
    {
        TIntermSymbol *symbol = new TIntermSymbol(variable);
        symbol->setLine(identifierLocation);
        declaration->appendDeclarator(symbol);
    }

    return declaration;
}

TIntermDeclaration *TParseContext::parseSingleInitDeclaration(const TPublicType &publicType,
                                                              const TSourceLoc &identifierLocation,
                                                              const ImmutableString &identifier,
                                                              const TSourceLoc &initLocation,
                                                              TIntermTyped *initializer)
{
    mDeferredNonEmptyDeclarationErrorCheck = false;

    declarationQualifierErrorCheck(publicType.qualifier, publicType.layoutQualifier,
                                   identifierLocation);

    nonEmptyDeclarationErrorCheck(publicType, identifierLocation);

    TIntermDeclaration *declaration = new TIntermDeclaration();
    declaration->setLine(identifierLocation);

    TIntermBinary *initNode = nullptr;
    TType *type             = new TType(publicType);
    if (executeInitializer(identifierLocation, identifier, type, initializer, &initNode))
    {
        if (initNode)
        {
            declaration->appendDeclarator(initNode);
        }
    }
    return declaration;
}

TIntermDeclaration *TParseContext::parseSingleArrayInitDeclaration(
    TPublicType &elementType,
    const TSourceLoc &identifierLocation,
    const ImmutableString &identifier,
    const TSourceLoc &indexLocation,
    const TVector<unsigned int> &arraySizes,
    const TSourceLoc &initLocation,
    TIntermTyped *initializer)
{
    mDeferredNonEmptyDeclarationErrorCheck = false;

    declarationQualifierErrorCheck(elementType.qualifier, elementType.layoutQualifier,
                                   identifierLocation);

    nonEmptyDeclarationErrorCheck(elementType, identifierLocation);

    checkIsValidTypeAndQualifierForArray(indexLocation, elementType);

    TType *arrayType = new TType(elementType);
    arrayType->makeArrays(arraySizes);

    TIntermDeclaration *declaration = new TIntermDeclaration();
    declaration->setLine(identifierLocation);

    // initNode will correspond to the whole of "type b[n] = initializer".
    TIntermBinary *initNode = nullptr;
    if (executeInitializer(identifierLocation, identifier, arrayType, initializer, &initNode))
    {
        if (initNode)
        {
            declaration->appendDeclarator(initNode);
        }
    }

    return declaration;
}

TIntermGlobalQualifierDeclaration *TParseContext::parseGlobalQualifierDeclaration(
    const TTypeQualifierBuilder &typeQualifierBuilder,
    const TSourceLoc &identifierLoc,
    const ImmutableString &identifier,
    const TSymbol *symbol)
{
    TTypeQualifier typeQualifier = typeQualifierBuilder.getVariableTypeQualifier(mDiagnostics);

    if (!typeQualifier.invariant && !typeQualifier.precise)
    {
        error(identifierLoc, "Expected invariant or precise", identifier);
        return nullptr;
    }
    if (typeQualifier.invariant && !checkIsAtGlobalLevel(identifierLoc, "invariant varying"))
    {
        return nullptr;
    }
    if (!symbol)
    {
        error(identifierLoc, "undeclared identifier declared as invariant or precise", identifier);
        return nullptr;
    }
    if (!IsQualifierUnspecified(typeQualifier.qualifier))
    {
        error(identifierLoc, "invariant or precise declaration specifies qualifier",
              getQualifierString(typeQualifier.qualifier));
    }
    if (typeQualifier.precision != EbpUndefined)
    {
        error(identifierLoc, "invariant or precise declaration specifies precision",
              getPrecisionString(typeQualifier.precision));
    }
    if (!typeQualifier.layoutQualifier.isEmpty())
    {
        error(identifierLoc, "invariant or precise declaration specifies layout", "'layout'");
    }

    const TVariable *variable = getNamedVariable(identifierLoc, identifier, symbol);
    if (!variable)
    {
        return nullptr;
    }
    const TType &type = variable->getType();

    checkInvariantVariableQualifier(typeQualifier.invariant, type.getQualifier(),
                                    typeQualifier.line);
    checkMemoryQualifierIsNotSpecified(typeQualifier.memoryQualifier, typeQualifier.line);

    symbolTable.addInvariantVarying(*variable);

    TIntermSymbol *intermSymbol = new TIntermSymbol(variable);
    intermSymbol->setLine(identifierLoc);

    return new TIntermGlobalQualifierDeclaration(intermSymbol, typeQualifier.precise,
                                                 identifierLoc);
}

void TParseContext::parseDeclarator(TPublicType &publicType,
                                    const TSourceLoc &identifierLocation,
                                    const ImmutableString &identifier,
                                    TIntermDeclaration *declarationOut)
{
    // If the declaration starting this declarator list was empty (example: int,), some checks were
    // not performed.
    if (mDeferredNonEmptyDeclarationErrorCheck)
    {
        nonEmptyDeclarationErrorCheck(publicType, identifierLocation);
        mDeferredNonEmptyDeclarationErrorCheck = false;
    }

    checkDeclaratorLocationIsNotSpecified(identifierLocation, publicType);

    TType *type = new TType(publicType);

    checkGeometryShaderInputAndSetArraySize(identifierLocation, identifier, type);
    checkTessellationShaderUnsizedArraysAndSetSize(identifierLocation, identifier, type);

    checkCanBeDeclaredWithoutInitializer(identifierLocation, identifier, type);

    if (IsAtomicCounter(type->getBasicType()))
    {
        checkAtomicCounterOffsetDoesNotOverlap(true, identifierLocation, type);

        checkAtomicCounterOffsetAlignment(identifierLocation, *type);
    }

    TVariable *variable = nullptr;
    if (declareVariable(identifierLocation, identifier, type, &variable))
    {
        TIntermSymbol *symbol = new TIntermSymbol(variable);
        symbol->setLine(identifierLocation);
        declarationOut->appendDeclarator(symbol);
    }
}

void TParseContext::parseArrayDeclarator(TPublicType &elementType,
                                         const TSourceLoc &identifierLocation,
                                         const ImmutableString &identifier,
                                         const TSourceLoc &arrayLocation,
                                         const TVector<unsigned int> &arraySizes,
                                         TIntermDeclaration *declarationOut)
{
    // If the declaration starting this declarator list was empty (example: int,), some checks were
    // not performed.
    if (mDeferredNonEmptyDeclarationErrorCheck)
    {
        nonEmptyDeclarationErrorCheck(elementType, identifierLocation);
        mDeferredNonEmptyDeclarationErrorCheck = false;
    }

    checkDeclaratorLocationIsNotSpecified(identifierLocation, elementType);

    if (checkIsValidTypeAndQualifierForArray(arrayLocation, elementType))
    {
        TType *arrayType = new TType(elementType);
        arrayType->makeArrays(arraySizes);

        checkGeometryShaderInputAndSetArraySize(identifierLocation, identifier, arrayType);
        checkTessellationShaderUnsizedArraysAndSetSize(identifierLocation, identifier, arrayType);

        checkCanBeDeclaredWithoutInitializer(identifierLocation, identifier, arrayType);

        if (IsAtomicCounter(arrayType->getBasicType()))
        {
            checkAtomicCounterOffsetDoesNotOverlap(true, identifierLocation, arrayType);

            checkAtomicCounterOffsetAlignment(identifierLocation, *arrayType);
        }

        TVariable *variable = nullptr;
        if (declareVariable(identifierLocation, identifier, arrayType, &variable))
        {
            TIntermSymbol *symbol = new TIntermSymbol(variable);
            symbol->setLine(identifierLocation);
            declarationOut->appendDeclarator(symbol);
        }
    }
}

void TParseContext::parseInitDeclarator(const TPublicType &publicType,
                                        const TSourceLoc &identifierLocation,
                                        const ImmutableString &identifier,
                                        const TSourceLoc &initLocation,
                                        TIntermTyped *initializer,
                                        TIntermDeclaration *declarationOut)
{
    // If the declaration starting this declarator list was empty (example: int,), some checks were
    // not performed.
    if (mDeferredNonEmptyDeclarationErrorCheck)
    {
        nonEmptyDeclarationErrorCheck(publicType, identifierLocation);
        mDeferredNonEmptyDeclarationErrorCheck = false;
    }

    checkDeclaratorLocationIsNotSpecified(identifierLocation, publicType);

    TIntermBinary *initNode = nullptr;
    TType *type             = new TType(publicType);
    if (executeInitializer(identifierLocation, identifier, type, initializer, &initNode))
    {
        //
        // build the intermediate representation
        //
        if (initNode)
        {
            declarationOut->appendDeclarator(initNode);
        }
    }
}

void TParseContext::parseArrayInitDeclarator(const TPublicType &elementType,
                                             const TSourceLoc &identifierLocation,
                                             const ImmutableString &identifier,
                                             const TSourceLoc &indexLocation,
                                             const TVector<unsigned int> &arraySizes,
                                             const TSourceLoc &initLocation,
                                             TIntermTyped *initializer,
                                             TIntermDeclaration *declarationOut)
{
    // If the declaration starting this declarator list was empty (example: int,), some checks were
    // not performed.
    if (mDeferredNonEmptyDeclarationErrorCheck)
    {
        nonEmptyDeclarationErrorCheck(elementType, identifierLocation);
        mDeferredNonEmptyDeclarationErrorCheck = false;
    }

    checkDeclaratorLocationIsNotSpecified(identifierLocation, elementType);

    checkIsValidTypeAndQualifierForArray(indexLocation, elementType);

    TType *arrayType = new TType(elementType);
    arrayType->makeArrays(arraySizes);

    // initNode will correspond to the whole of "b[n] = initializer".
    TIntermBinary *initNode = nullptr;
    if (executeInitializer(identifierLocation, identifier, arrayType, initializer, &initNode))
    {
        if (initNode)
        {
            declarationOut->appendDeclarator(initNode);
        }
    }
}

TIntermNode *TParseContext::addEmptyStatement(const TSourceLoc &location)
{
    // It's simpler to parse an empty statement as a constant expression rather than having a
    // different type of node just for empty statements, that will be pruned from the AST anyway.
    TIntermNode *node = CreateZeroNode(TType(EbtInt, EbpMedium));
    node->setLine(location);
    return node;
}

void TParseContext::setAtomicCounterBindingDefaultOffset(const TPublicType &publicType,
                                                         const TSourceLoc &location)
{
    const TLayoutQualifier &layoutQualifier = publicType.layoutQualifier;
    checkAtomicCounterBindingIsValid(location, layoutQualifier.binding);
    if (layoutQualifier.binding == -1 || layoutQualifier.offset == -1)
    {
        error(location, "Requires both binding and offset", "layout");
        return;
    }
    mAtomicCounterBindingStates[layoutQualifier.binding].setDefaultOffset(layoutQualifier.offset);
}

void TParseContext::parseDefaultPrecisionQualifier(const TPrecision precision,
                                                   const TPublicType &type,
                                                   const TSourceLoc &loc)
{
    if ((precision == EbpHigh) && (getShaderType() == GL_FRAGMENT_SHADER) &&
        !getFragmentPrecisionHigh())
    {
        error(loc, "precision is not supported in fragment shader", "highp");
    }

    if (!CanSetDefaultPrecisionOnType(type))
    {
        error(loc, "illegal type argument for default precision qualifier",
              getBasicString(type.getBasicType()));
        return;
    }
    symbolTable.setDefaultPrecision(type.getBasicType(), precision);
}

bool TParseContext::checkPrimitiveTypeMatchesTypeQualifier(const TTypeQualifier &typeQualifier)
{
    switch (typeQualifier.layoutQualifier.primitiveType)
    {
        case EptLines:
        case EptLinesAdjacency:
        case EptTriangles:
        case EptTrianglesAdjacency:
            return typeQualifier.qualifier == EvqGeometryIn;

        case EptLineStrip:
        case EptTriangleStrip:
            return typeQualifier.qualifier == EvqGeometryOut;

        case EptPoints:
            return true;

        default:
            UNREACHABLE();
            return false;
    }
}

void TParseContext::setGeometryShaderInputArraySize(unsigned int inputArraySize,
                                                    const TSourceLoc &line)
{
    if (!symbolTable.setGlInArraySize(inputArraySize))
    {
        error(line,
              "Array size or input primitive declaration doesn't match the size of earlier sized "
              "array inputs.",
              "layout");
    }
    mGeometryInputArraySize = inputArraySize;
}

bool TParseContext::parseGeometryShaderInputLayoutQualifier(const TTypeQualifier &typeQualifier)
{
    ASSERT(typeQualifier.qualifier == EvqGeometryIn);

    const TLayoutQualifier &layoutQualifier = typeQualifier.layoutQualifier;

    if (layoutQualifier.maxVertices != -1)
    {
        error(typeQualifier.line,
              "max_vertices can only be declared in 'out' layout in a geometry shader", "layout");
        return false;
    }

    // Set mGeometryInputPrimitiveType if exists
    if (layoutQualifier.primitiveType != EptUndefined)
    {
        if (!checkPrimitiveTypeMatchesTypeQualifier(typeQualifier))
        {
            error(typeQualifier.line, "invalid primitive type for 'in' layout", "layout");
            return false;
        }

        if (mGeometryShaderInputPrimitiveType == EptUndefined)
        {
            mGeometryShaderInputPrimitiveType = layoutQualifier.primitiveType;
            setGeometryShaderInputArraySize(
                GetGeometryShaderInputArraySize(mGeometryShaderInputPrimitiveType),
                typeQualifier.line);
        }
        else if (mGeometryShaderInputPrimitiveType != layoutQualifier.primitiveType)
        {
            error(typeQualifier.line, "primitive doesn't match earlier input primitive declaration",
                  "layout");
            return false;
        }
    }

    // Set mGeometryInvocations if exists
    if (layoutQualifier.invocations > 0)
    {
        if (mGeometryShaderInvocations == 0)
        {
            mGeometryShaderInvocations = layoutQualifier.invocations;
        }
        else if (mGeometryShaderInvocations != layoutQualifier.invocations)
        {
            error(typeQualifier.line, "invocations contradicts to the earlier declaration",
                  "layout");
            return false;
        }
    }

    return true;
}

bool TParseContext::parseGeometryShaderOutputLayoutQualifier(const TTypeQualifier &typeQualifier)
{
    ASSERT(typeQualifier.qualifier == EvqGeometryOut);

    const TLayoutQualifier &layoutQualifier = typeQualifier.layoutQualifier;

    if (layoutQualifier.invocations > 0)
    {
        error(typeQualifier.line,
              "invocations can only be declared in 'in' layout in a geometry shader", "layout");
        return false;
    }

    // Set mGeometryOutputPrimitiveType if exists
    if (layoutQualifier.primitiveType != EptUndefined)
    {
        if (!checkPrimitiveTypeMatchesTypeQualifier(typeQualifier))
        {
            error(typeQualifier.line, "invalid primitive type for 'out' layout", "layout");
            return false;
        }

        if (mGeometryShaderOutputPrimitiveType == EptUndefined)
        {
            mGeometryShaderOutputPrimitiveType = layoutQualifier.primitiveType;
        }
        else if (mGeometryShaderOutputPrimitiveType != layoutQualifier.primitiveType)
        {
            error(typeQualifier.line,
                  "primitive doesn't match earlier output primitive declaration", "layout");
            return false;
        }
    }

    // Set mGeometryMaxVertices if exists
    if (layoutQualifier.maxVertices > -1)
    {
        if (mGeometryShaderMaxVertices == -1)
        {
            mGeometryShaderMaxVertices = layoutQualifier.maxVertices;
        }
        else if (mGeometryShaderMaxVertices != layoutQualifier.maxVertices)
        {
            error(typeQualifier.line, "max_vertices contradicts to the earlier declaration",
                  "layout");
            return false;
        }
    }

    return true;
}

bool TParseContext::parseTessControlShaderOutputLayoutQualifier(const TTypeQualifier &typeQualifier)
{
    ASSERT(typeQualifier.qualifier == EvqTessControlOut);

    const TLayoutQualifier &layoutQualifier = typeQualifier.layoutQualifier;

    if (layoutQualifier.vertices == 0)
    {
        error(typeQualifier.line, "No vertices specified", "layout");
        return false;
    }

    // Set mTessControlShaderOutputVertices if exists
    if (mTessControlShaderOutputVertices == 0)
    {
        mTessControlShaderOutputVertices = layoutQualifier.vertices;
    }
    else
    {
        error(typeQualifier.line, "Duplicated vertices specified", "layout");
    }
    return true;
}

bool TParseContext::parseTessEvaluationShaderInputLayoutQualifier(
    const TTypeQualifier &typeQualifier)
{
    ASSERT(typeQualifier.qualifier == EvqTessEvaluationIn);

    const TLayoutQualifier &layoutQualifier = typeQualifier.layoutQualifier;

    // Set mTessEvaluationShaderInputPrimitiveType if exists
    if (layoutQualifier.tesPrimitiveType != EtetUndefined)
    {
        if (mTessEvaluationShaderInputPrimitiveType == EtetUndefined)
        {
            mTessEvaluationShaderInputPrimitiveType = layoutQualifier.tesPrimitiveType;
        }
        else
        {
            error(typeQualifier.line, "Duplicated primitive type declaration", "layout");
        }
    }
    // Set mTessEvaluationShaderVertexSpacingType if exists
    if (layoutQualifier.tesVertexSpacingType != EtetUndefined)
    {
        if (mTessEvaluationShaderInputVertexSpacingType == EtetUndefined)
        {
            mTessEvaluationShaderInputVertexSpacingType = layoutQualifier.tesVertexSpacingType;
        }
        else
        {
            error(typeQualifier.line, "Duplicated vertex spacing declaration", "layout");
        }
    }
    // Set mTessEvaluationShaderInputOrderingType if exists
    if (layoutQualifier.tesOrderingType != EtetUndefined)
    {
        if (mTessEvaluationShaderInputOrderingType == EtetUndefined)
        {
            mTessEvaluationShaderInputOrderingType = layoutQualifier.tesOrderingType;
        }
        else
        {
            error(typeQualifier.line, "Duplicated ordering declaration", "layout");
        }
    }
    // Set mTessEvaluationShaderInputPointType if exists
    if (layoutQualifier.tesPointType != EtetUndefined)
    {
        if (mTessEvaluationShaderInputPointType == EtetUndefined)
        {
            mTessEvaluationShaderInputPointType = layoutQualifier.tesPointType;
        }
        else
        {
            error(typeQualifier.line, "Duplicated point type declaration", "layout");
        }
    }

    return true;
}

void TParseContext::parseGlobalLayoutQualifier(const TTypeQualifierBuilder &typeQualifierBuilder)
{
    TTypeQualifier typeQualifier = typeQualifierBuilder.getVariableTypeQualifier(mDiagnostics);
    const TLayoutQualifier layoutQualifier = typeQualifier.layoutQualifier;

    checkInvariantVariableQualifier(typeQualifier.invariant, typeQualifier.qualifier,
                                    typeQualifier.line);

    // It should never be the case, but some strange parser errors can send us here.
    if (layoutQualifier.isEmpty())
    {
        error(typeQualifier.line, "Error during layout qualifier parsing.", "?");
        return;
    }

    if (!layoutQualifier.isCombinationValid())
    {
        error(typeQualifier.line, "invalid layout qualifier combination", "layout");
        return;
    }

    checkIndexIsNotSpecified(typeQualifier.line, layoutQualifier.index);

    checkBindingIsNotSpecified(typeQualifier.line, layoutQualifier.binding);

    checkMemoryQualifierIsNotSpecified(typeQualifier.memoryQualifier, typeQualifier.line);

    checkInternalFormatIsNotSpecified(typeQualifier.line, layoutQualifier.imageInternalFormat);

    checkYuvIsNotSpecified(typeQualifier.line, layoutQualifier.yuv);

    checkOffsetIsNotSpecified(typeQualifier.line, layoutQualifier.offset);

    checkStd430IsForShaderStorageBlock(typeQualifier.line, layoutQualifier.blockStorage,
                                       typeQualifier.qualifier);

    if (typeQualifier.qualifier != EvqFragmentIn)
    {
        checkEarlyFragmentTestsIsNotSpecified(typeQualifier.line,
                                              layoutQualifier.earlyFragmentTests);
    }

    if (typeQualifier.qualifier == EvqComputeIn)
    {
        if (mComputeShaderLocalSizeDeclared &&
            !layoutQualifier.isLocalSizeEqual(mComputeShaderLocalSize))
        {
            error(typeQualifier.line, "Work group size does not match the previous declaration",
                  "layout");
            return;
        }

        if (mShaderVersion < 310)
        {
            error(typeQualifier.line, "in type qualifier supported in GLSL ES 3.10 only", "layout");
            return;
        }

        if (!layoutQualifier.localSize.isAnyValueSet())
        {
            error(typeQualifier.line, "No local work group size specified", "layout");
            return;
        }

        const TVariable *maxComputeWorkGroupSize = static_cast<const TVariable *>(
            symbolTable.findBuiltIn(ImmutableString("gl_MaxComputeWorkGroupSize"), mShaderVersion));

        const TConstantUnion *maxComputeWorkGroupSizeData =
            maxComputeWorkGroupSize->getConstPointer();

        for (size_t i = 0u; i < layoutQualifier.localSize.size(); ++i)
        {
            if (layoutQualifier.localSize[i] != -1)
            {
                mComputeShaderLocalSize[i]             = layoutQualifier.localSize[i];
                const int maxComputeWorkGroupSizeValue = maxComputeWorkGroupSizeData[i].getIConst();
                if (mComputeShaderLocalSize[i] < 1 ||
                    mComputeShaderLocalSize[i] > maxComputeWorkGroupSizeValue)
                {
                    std::stringstream reasonStream = sh::InitializeStream<std::stringstream>();
                    reasonStream << "invalid value: Value must be at least 1 and no greater than "
                                 << maxComputeWorkGroupSizeValue;
                    const std::string &reason = reasonStream.str();

                    error(typeQualifier.line, reason.c_str(), getWorkGroupSizeString(i));
                    return;
                }
            }
        }

        mComputeShaderLocalSizeDeclared = true;
    }
    else if (typeQualifier.qualifier == EvqGeometryIn)
    {
        if (mShaderVersion < 310)
        {
            error(typeQualifier.line, "in type qualifier supported in GLSL ES 3.10 only", "layout");
            return;
        }

        if (!parseGeometryShaderInputLayoutQualifier(typeQualifier))
        {
            return;
        }
    }
    else if (typeQualifier.qualifier == EvqGeometryOut)
    {
        if (mShaderVersion < 310)
        {
            error(typeQualifier.line, "out type qualifier supported in GLSL ES 3.10 only",
                  "layout");
            return;
        }

        if (!parseGeometryShaderOutputLayoutQualifier(typeQualifier))
        {
            return;
        }
    }
    else if (anyMultiviewExtensionAvailable() && typeQualifier.qualifier == EvqVertexIn)
    {
        // This error is only specified in WebGL, but tightens unspecified behavior in the native
        // specification.
        if (mNumViews != -1 && layoutQualifier.numViews != mNumViews)
        {
            error(typeQualifier.line, "Number of views does not match the previous declaration",
                  "layout");
            return;
        }

        if (layoutQualifier.numViews == -1)
        {
            error(typeQualifier.line, "No num_views specified", "layout");
            return;
        }

        if (layoutQualifier.numViews > mMaxNumViews)
        {
            error(typeQualifier.line, "num_views greater than the value of GL_MAX_VIEWS_OVR",
                  "layout");
            return;
        }

        mNumViews = layoutQualifier.numViews;
    }
    else if (typeQualifier.qualifier == EvqFragmentIn)
    {
        if (mShaderVersion < 310)
        {
            error(typeQualifier.line,
                  "in type qualifier without variable declaration supported in GLSL ES 3.10 and "
                  "after",
                  "layout");
            return;
        }

        if (!layoutQualifier.earlyFragmentTests)
        {
            error(typeQualifier.line,
                  "only early_fragment_tests is allowed as layout qualifier when not declaring a "
                  "variable",
                  "layout");
            return;
        }

        mEarlyFragmentTestsSpecified = true;
    }
    else if (typeQualifier.qualifier == EvqTessControlOut)
    {
        if (mShaderVersion < 310)
        {
            error(typeQualifier.line, "out type qualifier supported in GLSL ES 3.10 and after",
                  "layout");
            return;
        }

        if (!parseTessControlShaderOutputLayoutQualifier(typeQualifier))
        {
            return;
        }
    }
    else if (typeQualifier.qualifier == EvqTessEvaluationIn)
    {
        if (mShaderVersion < 310)
        {
            error(typeQualifier.line, "in type qualifier supported in GLSL ES 3.10 and after",
                  "layout");
            return;
        }

        if (!parseTessEvaluationShaderInputLayoutQualifier(typeQualifier))
        {
            return;
        }
    }
    else
    {
        if (!checkWorkGroupSizeIsNotSpecified(typeQualifier.line, layoutQualifier))
        {
            return;
        }

        if (typeQualifier.qualifier != EvqUniform && typeQualifier.qualifier != EvqBuffer)
        {
            error(typeQualifier.line, "invalid qualifier: global layout can only be set for blocks",
                  getQualifierString(typeQualifier.qualifier));
            return;
        }

        if (mShaderVersion < 300)
        {
            error(typeQualifier.line, "layout qualifiers supported in GLSL ES 3.00 and after",
                  "layout");
            return;
        }

        checkLocationIsNotSpecified(typeQualifier.line, layoutQualifier);

        if (layoutQualifier.matrixPacking != EmpUnspecified)
        {
            if (typeQualifier.qualifier == EvqUniform)
            {
                mDefaultUniformMatrixPacking = layoutQualifier.matrixPacking;
            }
            else if (typeQualifier.qualifier == EvqBuffer)
            {
                mDefaultBufferMatrixPacking = layoutQualifier.matrixPacking;
            }
        }

        if (layoutQualifier.blockStorage != EbsUnspecified)
        {
            if (typeQualifier.qualifier == EvqUniform)
            {
                mDefaultUniformBlockStorage = layoutQualifier.blockStorage;
            }
            else if (typeQualifier.qualifier == EvqBuffer)
            {
                mDefaultBufferBlockStorage = layoutQualifier.blockStorage;
            }
        }
    }
}

TIntermFunctionPrototype *TParseContext::createPrototypeNodeFromFunction(
    const TFunction &function,
    const TSourceLoc &location,
    bool insertParametersToSymbolTable)
{
    checkIsNotReserved(location, function.name());

    TIntermFunctionPrototype *prototype = new TIntermFunctionPrototype(&function);
    prototype->setLine(location);

    for (size_t i = 0; i < function.getParamCount(); i++)
    {
        const TVariable *param = function.getParam(i);

        // If the parameter has no name, it's not an error, just don't add it to symbol table (could
        // be used for unused args).
        if (param->symbolType() != SymbolType::Empty)
        {
            if (insertParametersToSymbolTable)
            {
                if (!symbolTable.declare(const_cast<TVariable *>(param)))
                {
                    error(location, "redefinition", param->name());
                }
            }
            // Unsized type of a named parameter should have already been checked and sanitized.
            ASSERT(!param->getType().isUnsizedArray());
        }
        else
        {
            if (param->getType().isUnsizedArray())
            {
                error(location, "function parameter array must be sized at compile time", "[]");
                // We don't need to size the arrays since the parameter is unnamed and hence
                // inaccessible.
            }
        }
    }
    return prototype;
}

TIntermFunctionPrototype *TParseContext::addFunctionPrototypeDeclaration(
    const TFunction &parsedFunction,
    const TSourceLoc &location)
{
    // Note: function found from the symbol table could be the same as parsedFunction if this is the
    // first declaration. Either way the instance in the symbol table is used to track whether the
    // function is declared multiple times.
    bool hadPrototypeDeclaration = false;
    const TFunction *function    = symbolTable.markFunctionHasPrototypeDeclaration(
        parsedFunction.getMangledName(), &hadPrototypeDeclaration);

    if (hadPrototypeDeclaration && mShaderVersion == 100)
    {
        // ESSL 1.00.17 section 4.2.7.
        // Doesn't apply to ESSL 3.00.4: see section 4.2.3.
        error(location, "duplicate function prototype declarations are not allowed", "function");
    }

    TIntermFunctionPrototype *prototype =
        createPrototypeNodeFromFunction(*function, location, false);

    symbolTable.pop();

    if (!symbolTable.atGlobalLevel())
    {
        // ESSL 3.00.4 section 4.2.4.
        error(location, "local function prototype declarations are not allowed", "function");
    }

    return prototype;
}

TIntermFunctionDefinition *TParseContext::addFunctionDefinition(
    TIntermFunctionPrototype *functionPrototype,
    TIntermBlock *functionBody,
    const TSourceLoc &location)
{
    // Undo push at end of parseFunctionDefinitionHeader() below for ESSL1.00 case
    if (mFunctionBodyNewScope)
    {
        mFunctionBodyNewScope = false;
        symbolTable.pop();
    }

    // Check that non-void functions have at least one return statement.
    if (mCurrentFunctionType->getBasicType() != EbtVoid && !mFunctionReturnsValue)
    {
        error(location,
              "function does not return a value:", functionPrototype->getFunction()->name());
    }

    if (functionBody == nullptr)
    {
        functionBody = new TIntermBlock();
        functionBody->setLine(location);
    }
    TIntermFunctionDefinition *functionNode =
        new TIntermFunctionDefinition(functionPrototype, functionBody);
    functionNode->setLine(location);

    symbolTable.pop();
    return functionNode;
}

void TParseContext::parseFunctionDefinitionHeader(const TSourceLoc &location,
                                                  const TFunction *function,
                                                  TIntermFunctionPrototype **prototypeOut)
{
    ASSERT(function);

    bool wasDefined = false;
    function        = symbolTable.setFunctionParameterNamesFromDefinition(function, &wasDefined);
    if (wasDefined)
    {
        error(location, "function already has a body", function->name());
    }

    // Remember the return type for later checking for return statements.
    mCurrentFunctionType  = &(function->getReturnType());
    mFunctionReturnsValue = false;

    *prototypeOut = createPrototypeNodeFromFunction(*function, location, true);
    setLoopNestingLevel(0);

    // ESSL 1.00 spec allows for variable in function body to redefine parameter
    if (IsSpecWithFunctionBodyNewScope(mShaderSpec, mShaderVersion))
    {
        mFunctionBodyNewScope = true;
        symbolTable.push();
    }
}

TFunction *TParseContext::parseFunctionDeclarator(const TSourceLoc &location, TFunction *function)
{
    //
    // We don't know at this point whether this is a function definition or a prototype.
    // The definition production code will check for redefinitions.
    // In the case of ESSL 1.00 the prototype production code will also check for redeclarations.
    //

    for (size_t i = 0u; i < function->getParamCount(); ++i)
    {
        const TVariable *param = function->getParam(i);
        if (param->getType().isStructSpecifier())
        {
            // ESSL 3.00.6 section 12.10.
            error(location, "Function parameter type cannot be a structure definition",
                  function->name());
        }
    }

    if (getShaderVersion() >= 300)
    {

        if (symbolTable.isUnmangledBuiltInName(function->name(), getShaderVersion(),
                                               extensionBehavior()))
        {
            // With ESSL 3.00 and above, names of built-in functions cannot be redeclared as
            // functions. Therefore overloading or redefining builtin functions is an error.
            error(location, "Name of a built-in function cannot be redeclared as function",
                  function->name());
        }
    }
    else
    {
        // ESSL 1.00.17 section 4.2.6: built-ins can be overloaded but not redefined. We assume that
        // this applies to redeclarations as well.
        const TSymbol *builtIn =
            symbolTable.findBuiltIn(function->getMangledName(), getShaderVersion());
        if (builtIn)
        {
            error(location, "built-in functions cannot be redefined", function->name());
        }
    }

    // Return types and parameter qualifiers must match in all redeclarations, so those are checked
    // here.
    const TFunction *prevDec =
        static_cast<const TFunction *>(symbolTable.findGlobal(function->getMangledName()));
    if (prevDec)
    {
        if (prevDec->getReturnType() != function->getReturnType())
        {
            error(location, "function must have the same return type in all of its declarations",
                  function->getReturnType().getBasicString());
        }
        for (size_t i = 0; i < prevDec->getParamCount(); ++i)
        {
            if (prevDec->getParam(i)->getType().getQualifier() !=
                function->getParam(i)->getType().getQualifier())
            {
                error(location,
                      "function must have the same parameter qualifiers in all of its declarations",
                      function->getParam(i)->getType().getQualifierString());
            }
        }
    }

    // Check for previously declared variables using the same name.
    const TSymbol *prevSym   = symbolTable.find(function->name(), getShaderVersion());
    bool insertUnmangledName = true;
    if (prevSym)
    {
        if (!prevSym->isFunction())
        {
            error(location, "redefinition of a function", function->name());
        }
        insertUnmangledName = false;
    }
    // Parsing is at the inner scope level of the function's arguments and body statement at this
    // point, but declareUserDefinedFunction takes care of declaring the function at the global
    // scope.
    symbolTable.declareUserDefinedFunction(function, insertUnmangledName);

    // Raise error message if main function takes any parameters or return anything other than void
    if (function->isMain())
    {
        if (function->getParamCount() > 0)
        {
            error(location, "function cannot take any parameter(s)", "main");
        }
        if (function->getReturnType().getBasicType() != EbtVoid)
        {
            error(location, "main function cannot return a value",
                  function->getReturnType().getBasicString());
        }
    }

    //
    // If this is a redeclaration, it could also be a definition, in which case, we want to use the
    // variable names from this one, and not the one that's
    // being redeclared.  So, pass back up this declaration, not the one in the symbol table.
    //
    return function;
}

TFunction *TParseContext::parseFunctionHeader(const TPublicType &type,
                                              const ImmutableString &name,
                                              const TSourceLoc &location)
{
    if (type.qualifier != EvqGlobal && type.qualifier != EvqTemporary)
    {
        error(location, "no qualifiers allowed for function return",
              getQualifierString(type.qualifier));
    }
    if (!type.layoutQualifier.isEmpty())
    {
        error(location, "no qualifiers allowed for function return", "layout");
    }
    // make sure an opaque type is not involved as well...
    std::string reason(getBasicString(type.getBasicType()));
    reason += "s can't be function return values";
    checkIsNotOpaqueType(location, type.typeSpecifierNonArray, reason.c_str());
    if (mShaderVersion < 300)
    {
        // Array return values are forbidden, but there's also no valid syntax for declaring array
        // return values in ESSL 1.00.
        ASSERT(!type.isArray() || mDiagnostics->numErrors() > 0);

        if (type.isStructureContainingArrays())
        {
            // ESSL 1.00.17 section 6.1 Function Definitions
            TInfoSinkBase typeString;
            typeString << TType(type);
            error(location, "structures containing arrays can't be function return values",
                  typeString.c_str());
        }
    }

    // Add the function as a prototype after parsing it (we do not support recursion)
    return new TFunction(&symbolTable, name, SymbolType::UserDefined, new TType(type), false);
}

TFunctionLookup *TParseContext::addNonConstructorFunc(const ImmutableString &name,
                                                      const TSymbol *symbol)
{
    return TFunctionLookup::CreateFunctionCall(name, symbol);
}

TFunctionLookup *TParseContext::addConstructorFunc(const TPublicType &publicType)
{
    if (mShaderVersion < 300 && publicType.isArray())
    {
        error(publicType.getLine(), "array constructor supported in GLSL ES 3.00 and above only",
              "[]");
    }
    if (publicType.isStructSpecifier())
    {
        error(publicType.getLine(), "constructor can't be a structure definition",
              getBasicString(publicType.getBasicType()));
    }

    TType *type = new TType(publicType);
    if (!type->canBeConstructed())
    {
        error(publicType.getLine(), "cannot construct this type",
              getBasicString(publicType.getBasicType()));
        type->setBasicType(EbtFloat);
    }
    return TFunctionLookup::CreateConstructor(type);
}

void TParseContext::checkIsNotUnsizedArray(const TSourceLoc &line,
                                           const char *errorMessage,
                                           const ImmutableString &token,
                                           TType *arrayType)
{
    if (arrayType->isUnsizedArray())
    {
        error(line, errorMessage, token);
        arrayType->sizeUnsizedArrays(TSpan<const unsigned int>());
    }
}

TParameter TParseContext::parseParameterDeclarator(TType *type,
                                                   const ImmutableString &name,
                                                   const TSourceLoc &nameLoc)
{
    ASSERT(type);
    checkIsNotUnsizedArray(nameLoc, "function parameter array must specify a size", name, type);
    if (type->getBasicType() == EbtVoid)
    {
        error(nameLoc, "illegal use of type 'void'", name);
    }
    checkIsNotReserved(nameLoc, name);
    TParameter param = {name.data(), type};
    return param;
}

TParameter TParseContext::parseParameterDeclarator(const TPublicType &publicType,
                                                   const ImmutableString &name,
                                                   const TSourceLoc &nameLoc)
{
    TType *type = new TType(publicType);
    return parseParameterDeclarator(type, name, nameLoc);
}

TParameter TParseContext::parseParameterArrayDeclarator(const ImmutableString &name,
                                                        const TSourceLoc &nameLoc,
                                                        const TVector<unsigned int> &arraySizes,
                                                        const TSourceLoc &arrayLoc,
                                                        TPublicType *elementType)
{
    checkArrayElementIsNotArray(arrayLoc, *elementType);
    TType *arrayType = new TType(*elementType);
    arrayType->makeArrays(arraySizes);
    return parseParameterDeclarator(arrayType, name, nameLoc);
}

bool TParseContext::checkUnsizedArrayConstructorArgumentDimensionality(
    const TIntermSequence &arguments,
    TType type,
    const TSourceLoc &line)
{
    if (arguments.empty())
    {
        error(line, "implicitly sized array constructor must have at least one argument", "[]");
        return false;
    }
    for (TIntermNode *arg : arguments)
    {
        const TIntermTyped *element = arg->getAsTyped();
        ASSERT(element);
        size_t dimensionalityFromElement = element->getType().getNumArraySizes() + 1u;
        if (dimensionalityFromElement > type.getNumArraySizes())
        {
            error(line, "constructing from a non-dereferenced array", "constructor");
            return false;
        }
        else if (dimensionalityFromElement < type.getNumArraySizes())
        {
            if (dimensionalityFromElement == 1u)
            {
                error(line, "implicitly sized array of arrays constructor argument is not an array",
                      "constructor");
            }
            else
            {
                error(line,
                      "implicitly sized array of arrays constructor argument dimensionality is too "
                      "low",
                      "constructor");
            }
            return false;
        }
    }
    return true;
}

// This function is used to test for the correctness of the parameters passed to various constructor
// functions and also convert them to the right datatype if it is allowed and required.
//
// Returns a node to add to the tree regardless of if an error was generated or not.
//
TIntermTyped *TParseContext::addConstructor(TFunctionLookup *fnCall, const TSourceLoc &line)
{
    TType type                 = fnCall->constructorType();
    TIntermSequence &arguments = fnCall->arguments();
    if (type.isUnsizedArray())
    {
        if (!checkUnsizedArrayConstructorArgumentDimensionality(arguments, type, line))
        {
            type.sizeUnsizedArrays(TSpan<const unsigned int>());
            return CreateZeroNode(type);
        }
        TIntermTyped *firstElement = arguments.at(0)->getAsTyped();
        ASSERT(firstElement);
        if (type.getOutermostArraySize() == 0u)
        {
            type.sizeOutermostUnsizedArray(static_cast<unsigned int>(arguments.size()));
        }
        for (size_t i = 0; i < firstElement->getType().getNumArraySizes(); ++i)
        {
            if (type.getArraySizes()[i] == 0u)
            {
                type.setArraySize(i, firstElement->getType().getArraySizes()[i]);
            }
        }
        ASSERT(!type.isUnsizedArray());
    }

    if (!checkConstructorArguments(line, arguments, type))
    {
        return CreateZeroNode(type);
    }

    TIntermAggregate *constructorNode = TIntermAggregate::CreateConstructor(type, &arguments);
    constructorNode->setLine(line);

    return constructorNode->fold(mDiagnostics);
}

//
// Interface/uniform blocks
TIntermDeclaration *TParseContext::addInterfaceBlock(
    const TTypeQualifierBuilder &typeQualifierBuilder,
    const TSourceLoc &nameLine,
    const ImmutableString &blockName,
    TFieldList *fieldList,
    const ImmutableString &instanceName,
    const TSourceLoc &instanceLine,
    const TVector<unsigned int> *arraySizes,
    const TSourceLoc &arraySizesLine)
{
    checkIsNotReserved(nameLine, blockName);

    TTypeQualifier typeQualifier = typeQualifierBuilder.getVariableTypeQualifier(mDiagnostics);

    const bool isUniformOrBuffer =
        typeQualifier.qualifier == EvqUniform || typeQualifier.qualifier == EvqBuffer;
    const bool isShaderIoBlock = IsShaderIoBlock(typeQualifier.qualifier);

    if (mShaderVersion < 310 && typeQualifier.qualifier != EvqUniform)
    {
        error(typeQualifier.line,
              "invalid qualifier: interface blocks must be uniform in version lower than GLSL ES "
              "3.10",
              getQualifierString(typeQualifier.qualifier));
    }
    else if (typeQualifier.qualifier == EvqPatchOut)
    {
        if ((!isExtensionEnabled(TExtension::EXT_tessellation_shader) && mShaderVersion < 320) ||
            mShaderType != GL_TESS_CONTROL_SHADER)
        {
            error(typeQualifier.line,
                  "invalid qualifier: 'patch out' requires a tessellation control shader",
                  getQualifierString(typeQualifier.qualifier));
        }
    }
    else if (typeQualifier.qualifier == EvqPatchIn)
    {
        if ((!isExtensionEnabled(TExtension::EXT_tessellation_shader) && mShaderVersion < 320) ||
            mShaderType != GL_TESS_EVALUATION_SHADER)
        {
            error(typeQualifier.line,
                  "invalid qualifier: 'patch in' requires a tessellation evaluation shader",
                  getQualifierString(typeQualifier.qualifier));
        }
    }
    else if (typeQualifier.qualifier != EvqUniform && typeQualifier.qualifier != EvqBuffer)
    {
        if (isShaderIoBlock)
        {
            if (!isExtensionEnabled(TExtension::OES_shader_io_blocks) &&
                !isExtensionEnabled(TExtension::EXT_shader_io_blocks) && mShaderVersion < 320)
            {
                error(typeQualifier.line,
                      "invalid qualifier: shader IO blocks need shader io block extension",
                      getQualifierString(typeQualifier.qualifier));
            }

            if (mShaderType == GL_TESS_CONTROL_SHADER && arraySizes == nullptr)
            {
                error(typeQualifier.line, "type must be an array", blockName);
            }
        }
        else
        {
            error(typeQualifier.line,
                  "invalid qualifier: interface blocks must be uniform or buffer",
                  getQualifierString(typeQualifier.qualifier));
        }
    }

    if (typeQualifier.invariant)
    {
        error(typeQualifier.line, "invalid qualifier on interface block member", "invariant");
    }

    if (typeQualifier.qualifier != EvqBuffer)
    {
        checkMemoryQualifierIsNotSpecified(typeQualifier.memoryQualifier, typeQualifier.line);
    }

    // Verify array sizes
    if (arraySizes)
    {
        if (isUniformOrBuffer)
        {
            if (arraySizes->size() == 0)
            {
                error(arraySizesLine, "unsized arrays are not allowed with interface blocks", "");
            }
            if (arraySizes->size() > 1)
            {
                error(arraySizesLine, "array of arrays are not allowed with interface blocks", "");
            }
        }
        else if (isShaderIoBlock)
        {
            size_t arrayDimensions = arraySizes->size();

            // Geometry shader inputs have a level arrayness that must be ignored.
            if (mShaderType == GL_GEOMETRY_SHADER_EXT && IsVaryingIn(typeQualifier.qualifier))
            {
                ASSERT(arrayDimensions > 0);
                --arrayDimensions;

                // Validate that the array size of input matches the geometry layout
                // declaration, if not automatic (specified as []).
                const unsigned int geometryDim = arraySizes->back();
                if (geometryDim > 0 && geometryDim != mGeometryInputArraySize)
                {
                    error(arraySizesLine,
                          "geometry shader input block array size inconsistent "
                          "with primitive",
                          "");
                }
            }

            if (arrayDimensions > 1)
            {
                error(arraySizesLine, "array of arrays are not allowed with I/O blocks", "");
            }
        }
    }
    else if (isShaderIoBlock && mShaderType == GL_GEOMETRY_SHADER_EXT &&
             IsVaryingIn(typeQualifier.qualifier))
    {
        error(arraySizesLine, "geometry shader input blocks must be an array", "");
    }

    checkIndexIsNotSpecified(typeQualifier.line, typeQualifier.layoutQualifier.index);

    if (mShaderVersion < 310)
    {
        checkBindingIsNotSpecified(typeQualifier.line, typeQualifier.layoutQualifier.binding);
    }
    else
    {
        unsigned int arraySize =
            arraySizes == nullptr || arraySizes->empty() ? 0 : (*arraySizes)[0];
        checkBlockBindingIsValid(typeQualifier.line, typeQualifier.qualifier,
                                 typeQualifier.layoutQualifier.binding, arraySize);
    }

    checkYuvIsNotSpecified(typeQualifier.line, typeQualifier.layoutQualifier.yuv);
    checkEarlyFragmentTestsIsNotSpecified(typeQualifier.line,
                                          typeQualifier.layoutQualifier.earlyFragmentTests);
    checkNoncoherentIsNotSpecified(typeQualifier.line, typeQualifier.layoutQualifier.noncoherent);

    TLayoutQualifier blockLayoutQualifier = typeQualifier.layoutQualifier;
    if (!IsShaderIoBlock(typeQualifier.qualifier) && typeQualifier.qualifier != EvqPatchIn &&
        typeQualifier.qualifier != EvqPatchOut)
    {
        checkLocationIsNotSpecified(typeQualifier.line, blockLayoutQualifier);
    }
    checkStd430IsForShaderStorageBlock(typeQualifier.line, blockLayoutQualifier.blockStorage,
                                       typeQualifier.qualifier);

    if (blockLayoutQualifier.matrixPacking == EmpUnspecified)
    {
        if (typeQualifier.qualifier == EvqUniform)
        {
            blockLayoutQualifier.matrixPacking = mDefaultUniformMatrixPacking;
        }
        else if (typeQualifier.qualifier == EvqBuffer)
        {
            blockLayoutQualifier.matrixPacking = mDefaultBufferMatrixPacking;
        }
    }

    if (blockLayoutQualifier.blockStorage == EbsUnspecified)
    {
        if (typeQualifier.qualifier == EvqUniform)
        {
            blockLayoutQualifier.blockStorage = mDefaultUniformBlockStorage;
        }
        else if (typeQualifier.qualifier == EvqBuffer)
        {
            blockLayoutQualifier.blockStorage = mDefaultBufferBlockStorage;
        }
    }

    checkWorkGroupSizeIsNotSpecified(nameLine, blockLayoutQualifier);

    checkInternalFormatIsNotSpecified(nameLine, blockLayoutQualifier.imageInternalFormat);

    // check for sampler types and apply layout qualifiers
    for (size_t memberIndex = 0; memberIndex < fieldList->size(); ++memberIndex)
    {
        TField *field    = (*fieldList)[memberIndex];
        TType *fieldType = field->type();
        if (IsOpaqueType(fieldType->getBasicType()))
        {
            std::string reason("unsupported type - ");
            reason += fieldType->getBasicString();
            reason += " types are not allowed in interface blocks";
            error(field->line(), reason.c_str(), fieldType->getBasicString());
        }

        const TQualifier qualifier = fieldType->getQualifier();
        switch (qualifier)
        {
            case EvqGlobal:
                break;
            case EvqUniform:
                if (typeQualifier.qualifier == EvqBuffer)
                {
                    error(field->line(), "invalid qualifier on shader storage block member",
                          getQualifierString(qualifier));
                }
                break;
            case EvqBuffer:
                if (typeQualifier.qualifier == EvqUniform)
                {
                    error(field->line(), "invalid qualifier on uniform block member",
                          getQualifierString(qualifier));
                }
                break;
            // a member variable in io block may have different interpolation.
            case EvqFlatIn:
            case EvqFlatOut:
            case EvqNoPerspectiveIn:
            case EvqNoPerspectiveOut:
            case EvqSmoothIn:
            case EvqSmoothOut:
            case EvqCentroidIn:
            case EvqCentroidOut:
                break;
            // a member variable can have an incomplete qualifier because shader io block has either
            // in or out.
            case EvqSmooth:
            case EvqFlat:
            case EvqNoPerspective:
            case EvqCentroid:
                if (!IsShaderIoBlock(typeQualifier.qualifier) &&
                    typeQualifier.qualifier != EvqPatchIn && typeQualifier.qualifier != EvqPatchOut)
                {
                    error(field->line(), "invalid qualifier on interface block member",
                          getQualifierString(qualifier));
                }
                break;
            default:
                error(field->line(), "invalid qualifier on interface block member",
                      getQualifierString(qualifier));
                break;
        }

        if (fieldType->isInvariant())
        {
            error(field->line(), "invalid qualifier on interface block member", "invariant");
        }

        // check layout qualifiers
        TLayoutQualifier fieldLayoutQualifier = fieldType->getLayoutQualifier();
        checkIndexIsNotSpecified(field->line(), fieldLayoutQualifier.index);
        checkBindingIsNotSpecified(field->line(), fieldLayoutQualifier.binding);

        if (fieldLayoutQualifier.blockStorage != EbsUnspecified)
        {
            error(field->line(), "invalid layout qualifier: cannot be used here",
                  getBlockStorageString(fieldLayoutQualifier.blockStorage));
        }

        if (fieldLayoutQualifier.matrixPacking == EmpUnspecified)
        {
            fieldLayoutQualifier.matrixPacking = blockLayoutQualifier.matrixPacking;
        }
        else if (!fieldType->isMatrix() && fieldType->getBasicType() != EbtStruct)
        {
            warning(field->line(),
                    "extraneous layout qualifier: only has an effect on matrix types",
                    getMatrixPackingString(fieldLayoutQualifier.matrixPacking));
        }

        fieldType->setLayoutQualifier(fieldLayoutQualifier);

        if (mShaderVersion < 310 || memberIndex != fieldList->size() - 1u ||
            typeQualifier.qualifier != EvqBuffer)
        {
            // ESSL 3.10 spec section 4.1.9 allows for runtime-sized arrays.
            checkIsNotUnsizedArray(field->line(),
                                   "array members of interface blocks must specify a size",
                                   field->name(), field->type());
        }

        if (typeQualifier.qualifier == EvqBuffer)
        {
            // set memory qualifiers
            // GLSL ES 3.10 session 4.9 [Memory Access Qualifiers]. When a block declaration is
            // qualified with a memory qualifier, it is as if all of its members were declared with
            // the same memory qualifier.
            const TMemoryQualifier &blockMemoryQualifier = typeQualifier.memoryQualifier;
            TMemoryQualifier fieldMemoryQualifier        = fieldType->getMemoryQualifier();
            fieldMemoryQualifier.readonly |= blockMemoryQualifier.readonly;
            fieldMemoryQualifier.writeonly |= blockMemoryQualifier.writeonly;
            fieldMemoryQualifier.coherent |= blockMemoryQualifier.coherent;
            fieldMemoryQualifier.restrictQualifier |= blockMemoryQualifier.restrictQualifier;
            fieldMemoryQualifier.volatileQualifier |= blockMemoryQualifier.volatileQualifier;
            // TODO(jiajia.qin@intel.com): Decide whether if readonly and writeonly buffer variable
            // is legal. See bug https://github.com/KhronosGroup/OpenGL-API/issues/7
            fieldType->setMemoryQualifier(fieldMemoryQualifier);
        }
    }

    TInterfaceBlock *interfaceBlock = new TInterfaceBlock(
        &symbolTable, blockName, fieldList, blockLayoutQualifier, SymbolType::UserDefined);
    if (!symbolTable.declare(interfaceBlock))
    {
        error(nameLine, "redefinition of an interface block name", blockName);
    }

    TType *interfaceBlockType =
        new TType(interfaceBlock, typeQualifier.qualifier, blockLayoutQualifier);
    if (arraySizes)
    {
        interfaceBlockType->makeArrays(*arraySizes);
    }

    // The instance variable gets created to refer to the interface block type from the AST
    // regardless of if there's an instance name. It's created as an empty symbol if there is no
    // instance name.
    TVariable *instanceVariable =
        new TVariable(&symbolTable, instanceName, interfaceBlockType,
                      instanceName.empty() ? SymbolType::Empty : SymbolType::UserDefined);

    if (instanceVariable->symbolType() == SymbolType::Empty)
    {
        // define symbols for the members of the interface block
        for (size_t memberIndex = 0; memberIndex < fieldList->size(); ++memberIndex)
        {
            TField *field    = (*fieldList)[memberIndex];
            TType *fieldType = new TType(*field->type());

            // set parent pointer of the field variable
            fieldType->setInterfaceBlock(interfaceBlock);

            fieldType->setQualifier(typeQualifier.qualifier);

            TVariable *fieldVariable =
                new TVariable(&symbolTable, field->name(), fieldType, SymbolType::UserDefined);
            if (!symbolTable.declare(fieldVariable))
            {
                error(field->line(), "redefinition of an interface block member name",
                      field->name());
            }
        }
    }
    else
    {
        checkIsNotReserved(instanceLine, instanceName);

        // add a symbol for this interface block
        if (!symbolTable.declare(instanceVariable))
        {
            error(instanceLine, "redefinition of an interface block instance name", instanceName);
        }
    }

    TIntermSymbol *blockSymbol = new TIntermSymbol(instanceVariable);
    blockSymbol->setLine(typeQualifier.line);
    TIntermDeclaration *declaration = new TIntermDeclaration();
    declaration->appendDeclarator(blockSymbol);
    declaration->setLine(nameLine);

    exitStructDeclaration();
    return declaration;
}

void TParseContext::enterStructDeclaration(const TSourceLoc &line,
                                           const ImmutableString &identifier)
{
    ++mStructNestingLevel;

    // Embedded structure definitions are not supported per GLSL ES spec.
    // ESSL 1.00.17 section 10.9. ESSL 3.00.6 section 12.11.
    if (mStructNestingLevel > 1)
    {
        error(line, "Embedded struct definitions are not allowed", "struct");
    }
}

void TParseContext::exitStructDeclaration()
{
    --mStructNestingLevel;
}

void TParseContext::checkIsBelowStructNestingLimit(const TSourceLoc &line, const TField &field)
{
    if (!sh::IsWebGLBasedSpec(mShaderSpec))
    {
        return;
    }

    if (field.type()->getBasicType() != EbtStruct)
    {
        return;
    }

    // We're already inside a structure definition at this point, so add
    // one to the field's struct nesting.
    if (1 + field.type()->getDeepestStructNesting() > kWebGLMaxStructNesting)
    {
        std::stringstream reasonStream = sh::InitializeStream<std::stringstream>();
        if (field.type()->getStruct()->symbolType() == SymbolType::Empty)
        {
            // This may happen in case there are nested struct definitions. While they are also
            // invalid GLSL, they don't cause a syntax error.
            reasonStream << "Struct nesting";
        }
        else
        {
            reasonStream << "Reference of struct type " << field.type()->getStruct()->name();
        }
        reasonStream << " exceeds maximum allowed nesting level of " << kWebGLMaxStructNesting;
        std::string reason = reasonStream.str();
        error(line, reason.c_str(), field.name());
        return;
    }
}

//
// Parse an array index expression
//
TIntermTyped *TParseContext::addIndexExpression(TIntermTyped *baseExpression,
                                                const TSourceLoc &location,
                                                TIntermTyped *indexExpression)
{
    if (!baseExpression->isArray() && !baseExpression->isMatrix() && !baseExpression->isVector())
    {
        if (baseExpression->getAsSymbolNode())
        {
            error(location, " left of '[' is not of type array, matrix, or vector ",
                  baseExpression->getAsSymbolNode()->getName());
        }
        else
        {
            error(location, " left of '[' is not of type array, matrix, or vector ", "expression");
        }

        return CreateZeroNode(TType(EbtFloat, EbpHigh, EvqConst));
    }

    if (baseExpression->getQualifier() == EvqPerVertexIn)
    {
        if (mGeometryShaderInputPrimitiveType == EptUndefined &&
            mShaderType == GL_GEOMETRY_SHADER_EXT)
        {
            error(location, "missing input primitive declaration before indexing gl_in.", "[");
            return CreateZeroNode(TType(EbtFloat, EbpHigh, EvqConst));
        }
    }

    if (mShaderType == GL_TESS_CONTROL_SHADER &&
        IsTessellationControlShaderOutput(mShaderType, baseExpression->getQualifier()))
    {
        const TIntermSymbol *intermSymbol = indexExpression->getAsSymbolNode();
        if (!intermSymbol || intermSymbol->getName() != "gl_InvocationID")
        {
            error(location,
                  "tessellation-control per-vertex output l-value must be indexed with "
                  "gl_InvocationID",
                  "[");
            return CreateZeroNode(TType(EbtFloat, EbpHigh, EvqConst));
        }
    }

    TIntermConstantUnion *indexConstantUnion = indexExpression->getAsConstantUnion();

    // ES3.2 or ES3.1's EXT_gpu_shader5 allow dynamically uniform expressions to be used as indices
    // of opaque types (samplers and atomic counters) as well as UBOs, but not SSBOs and images.
    bool allowUniformIndices =
        mShaderVersion >= 320 || isExtensionEnabled(TExtension::EXT_gpu_shader5);

    // ANGLE should be able to fold any constant expressions resulting in an integer - but to be
    // safe we don't treat "EvqConst" that's evaluated according to the spec as being sufficient
    // for constness. Some interpretations of the spec have allowed constant expressions with side
    // effects - like array length() method on a non-constant array.
    if (indexExpression->getQualifier() != EvqConst || indexConstantUnion == nullptr)
    {
        if (baseExpression->isInterfaceBlock())
        {
            switch (baseExpression->getQualifier())
            {
                case EvqPerVertexIn:
                    break;
                case EvqUniform:
                    if (!allowUniformIndices)
                    {
                        error(location,
                              "array indexes for uniform block arrays must be constant integral "
                              "expressions",
                              "[");
                    }
                    break;
                case EvqBuffer:
                    error(location,
                          "array indexes for shader storage block arrays must be constant integral "
                          "expressions",
                          "[");
                    break;
                default:
                    // It's ok for shader I/O blocks to be dynamically indexed
                    if (!IsShaderIoBlock(baseExpression->getQualifier()) &&
                        baseExpression->getQualifier() != EvqPatchIn &&
                        baseExpression->getQualifier() != EvqPatchOut)
                    {
                        // We can reach here only in error cases.
                        ASSERT(mDiagnostics->numErrors() > 0);
                    }
                    break;
            }
        }
        else if (baseExpression->getQualifier() == EvqFragmentOut)
        {
            error(location,
                  "array indexes for fragment outputs must be constant integral expressions", "[");
        }
        else if (mShaderSpec == SH_WEBGL2_SPEC && baseExpression->getQualifier() == EvqFragData)
        {
            error(location, "array index for gl_FragData must be constant zero", "[");
        }
        else if (baseExpression->isArray())
        {
            TBasicType elementType = baseExpression->getType().getBasicType();

            // Note: In Section 12.30 of the ESSL 3.00 spec on p143-144:
            //
            //   Indexing of arrays of samplers by constant-index-expressions is
            //   supported in GLSL ES 1.00. A constant-index-expression is an
            //   expression formed from constant-expressions and certain loop indices,
            //   defined for a subset of loop constructs. Should this functionality be
            //   included in GLSL ES 3.00?
            //
            //   RESOLUTION: No. Arrays of samplers may only be indexed by constant-
            //   integral-expressions.
            if (IsSampler(elementType) && !allowUniformIndices && mShaderVersion > 100)
            {
                error(location, "array index for samplers must be constant integral expressions",
                      "[");
            }
            else if (IsImage(elementType))
            {
                error(location,
                      "array indexes for image arrays must be constant integral expressions", "[");
            }
        }
    }

    if (indexConstantUnion)
    {
        // If an out-of-range index is not qualified as constant, the behavior in the spec is
        // undefined. This applies even if ANGLE has been able to constant fold it (ANGLE may
        // constant fold expressions that are not constant expressions). The most compatible way to
        // handle this case is to report a warning instead of an error and force the index to be in
        // the correct range.
        bool outOfRangeIndexIsError = indexExpression->getQualifier() == EvqConst;
        int index                   = 0;
        if (indexConstantUnion->getBasicType() == EbtInt)
        {
            index = indexConstantUnion->getIConst(0);
        }
        else if (indexConstantUnion->getBasicType() == EbtUInt)
        {
            index = static_cast<int>(indexConstantUnion->getUConst(0));
        }

        int safeIndex = -1;

        if (index < 0)
        {
            outOfRangeError(outOfRangeIndexIsError, location, "index expression is negative", "[]");
            safeIndex = 0;
        }

        if (!baseExpression->getType().isUnsizedArray())
        {
            if (baseExpression->isArray())
            {
                if (baseExpression->getQualifier() == EvqFragData && index > 0)
                {
                    if (!isExtensionEnabled(TExtension::EXT_draw_buffers))
                    {
                        outOfRangeError(outOfRangeIndexIsError, location,
                                        "array index for gl_FragData must be zero when "
                                        "GL_EXT_draw_buffers is disabled",
                                        "[]");
                        safeIndex = 0;
                    }
                }
            }
            // Only do generic out-of-range check if similar error hasn't already been reported.
            if (safeIndex < 0)
            {
                if (baseExpression->isArray())
                {
                    safeIndex = checkIndexLessThan(outOfRangeIndexIsError, location, index,
                                                   baseExpression->getOutermostArraySize(),
                                                   "array index out of range");
                }
                else if (baseExpression->isMatrix())
                {
                    safeIndex = checkIndexLessThan(outOfRangeIndexIsError, location, index,
                                                   baseExpression->getType().getCols(),
                                                   "matrix field selection out of range");
                }
                else
                {
                    ASSERT(baseExpression->isVector());
                    safeIndex = checkIndexLessThan(outOfRangeIndexIsError, location, index,
                                                   baseExpression->getType().getNominalSize(),
                                                   "vector field selection out of range");
                }
            }

            ASSERT(safeIndex >= 0);
            // Data of constant unions can't be changed, because it may be shared with other
            // constant unions or even builtins, like gl_MaxDrawBuffers. Instead use a new
            // sanitized object.
            if (safeIndex != index || indexConstantUnion->getBasicType() != EbtInt)
            {
                TConstantUnion *safeConstantUnion = new TConstantUnion();
                safeConstantUnion->setIConst(safeIndex);
                indexExpression = new TIntermConstantUnion(
                    safeConstantUnion, TType(EbtInt, indexExpression->getPrecision(),
                                             indexExpression->getQualifier()));
            }

            TIntermBinary *node =
                new TIntermBinary(EOpIndexDirect, baseExpression, indexExpression);
            node->setLine(location);
            return expressionOrFoldedResult(node);
        }
    }

    markStaticReadIfSymbol(indexExpression);
    TIntermBinary *node = new TIntermBinary(EOpIndexIndirect, baseExpression, indexExpression);
    node->setLine(location);
    // Indirect indexing can never be constant folded.
    return node;
}

int TParseContext::checkIndexLessThan(bool outOfRangeIndexIsError,
                                      const TSourceLoc &location,
                                      int index,
                                      int arraySize,
                                      const char *reason)
{
    // Should not reach here with an unsized / runtime-sized array.
    ASSERT(arraySize > 0);
    // A negative index should already have been checked.
    ASSERT(index >= 0);
    if (index >= arraySize)
    {
        std::stringstream reasonStream = sh::InitializeStream<std::stringstream>();
        reasonStream << reason << " '" << index << "'";
        std::string token = reasonStream.str();
        outOfRangeError(outOfRangeIndexIsError, location, reason, "[]");
        return arraySize - 1;
    }
    return index;
}

TIntermTyped *TParseContext::addFieldSelectionExpression(TIntermTyped *baseExpression,
                                                         const TSourceLoc &dotLocation,
                                                         const ImmutableString &fieldString,
                                                         const TSourceLoc &fieldLocation)
{
    if (baseExpression->isArray())
    {
        error(fieldLocation, "cannot apply dot operator to an array", ".");
        return baseExpression;
    }

    if (baseExpression->isVector())
    {
        TVector<int> fieldOffsets;
        if (!parseVectorFields(fieldLocation, fieldString, baseExpression->getNominalSize(),
                               &fieldOffsets))
        {
            fieldOffsets.resize(1);
            fieldOffsets[0] = 0;
        }
        TIntermSwizzle *node = new TIntermSwizzle(baseExpression, fieldOffsets);
        node->setLine(dotLocation);

        return node->fold(mDiagnostics);
    }
    else if (baseExpression->getBasicType() == EbtStruct)
    {
        const TFieldList &fields = baseExpression->getType().getStruct()->fields();
        if (fields.empty())
        {
            error(dotLocation, "structure has no fields", "Internal Error");
            return baseExpression;
        }
        else
        {
            bool fieldFound = false;
            unsigned int i;
            for (i = 0; i < fields.size(); ++i)
            {
                if (fields[i]->name() == fieldString)
                {
                    fieldFound = true;
                    break;
                }
            }
            if (fieldFound)
            {
                TIntermTyped *index = CreateIndexNode(i);
                index->setLine(fieldLocation);
                TIntermBinary *node =
                    new TIntermBinary(EOpIndexDirectStruct, baseExpression, index);
                node->setLine(dotLocation);
                return expressionOrFoldedResult(node);
            }
            else
            {
                error(dotLocation, " no such field in structure", fieldString);
                return baseExpression;
            }
        }
    }
    else if (baseExpression->isInterfaceBlock())
    {
        const TFieldList &fields = baseExpression->getType().getInterfaceBlock()->fields();
        if (fields.empty())
        {
            error(dotLocation, "interface block has no fields", "Internal Error");
            return baseExpression;
        }
        else
        {
            bool fieldFound = false;
            unsigned int i;
            for (i = 0; i < fields.size(); ++i)
            {
                if (fields[i]->name() == fieldString)
                {
                    fieldFound = true;
                    break;
                }
            }
            if (fieldFound)
            {
                TIntermTyped *index = CreateIndexNode(i);
                index->setLine(fieldLocation);
                TIntermBinary *node =
                    new TIntermBinary(EOpIndexDirectInterfaceBlock, baseExpression, index);
                node->setLine(dotLocation);
                // Indexing interface blocks can never be constant folded.
                return node;
            }
            else
            {
                error(dotLocation, " no such field in interface block", fieldString);
                return baseExpression;
            }
        }
    }
    else
    {
        if (mShaderVersion < 300)
        {
            error(dotLocation, " field selection requires structure or vector on left hand side",
                  fieldString);
        }
        else
        {
            error(dotLocation,
                  " field selection requires structure, vector, or interface block on left hand "
                  "side",
                  fieldString);
        }
        return baseExpression;
    }
}

TLayoutQualifier TParseContext::parseLayoutQualifier(const ImmutableString &qualifierType,
                                                     const TSourceLoc &qualifierTypeLine)
{
    TLayoutQualifier qualifier = TLayoutQualifier::Create();

    if (qualifierType == "shared")
    {
        if (sh::IsWebGLBasedSpec(mShaderSpec))
        {
            error(qualifierTypeLine, "Only std140 layout is allowed in WebGL", "shared");
        }
        qualifier.blockStorage = EbsShared;
    }
    else if (qualifierType == "packed")
    {
        if (sh::IsWebGLBasedSpec(mShaderSpec))
        {
            error(qualifierTypeLine, "Only std140 layout is allowed in WebGL", "packed");
        }
        qualifier.blockStorage = EbsPacked;
    }
    else if (qualifierType == "std430")
    {
        checkLayoutQualifierSupported(qualifierTypeLine, qualifierType, 310);
        qualifier.blockStorage = EbsStd430;
    }
    else if (qualifierType == "std140")
    {
        qualifier.blockStorage = EbsStd140;
    }
    else if (qualifierType == "row_major")
    {
        qualifier.matrixPacking = EmpRowMajor;
    }
    else if (qualifierType == "column_major")
    {
        qualifier.matrixPacking = EmpColumnMajor;
    }
    else if (qualifierType == "location")
    {
        error(qualifierTypeLine, "invalid layout qualifier: location requires an argument",
              qualifierType);
    }
    else if (qualifierType == "yuv" && mShaderType == GL_FRAGMENT_SHADER)
    {
        if (checkCanUseExtension(qualifierTypeLine, TExtension::EXT_YUV_target))
        {
            qualifier.yuv = true;
        }
    }
    else if (qualifierType == "early_fragment_tests")
    {
        checkLayoutQualifierSupported(qualifierTypeLine, qualifierType, 310);
        qualifier.earlyFragmentTests = true;
    }
    else if (qualifierType == "rgba32f")
    {
        checkLayoutQualifierSupported(qualifierTypeLine, qualifierType, 310);
        qualifier.imageInternalFormat = EiifRGBA32F;
    }
    else if (qualifierType == "rgba16f")
    {
        checkLayoutQualifierSupported(qualifierTypeLine, qualifierType, 310);
        qualifier.imageInternalFormat = EiifRGBA16F;
    }
    else if (qualifierType == "r32f")
    {
        checkLayoutQualifierSupported(qualifierTypeLine, qualifierType, 310);
        qualifier.imageInternalFormat = EiifR32F;
    }
    else if (qualifierType == "rgba8")
    {
        checkLayoutQualifierSupported(qualifierTypeLine, qualifierType, 310);
        qualifier.imageInternalFormat = EiifRGBA8;
    }
    else if (qualifierType == "rgba8_snorm")
    {
        checkLayoutQualifierSupported(qualifierTypeLine, qualifierType, 310);
        qualifier.imageInternalFormat = EiifRGBA8_SNORM;
    }
    else if (qualifierType == "rgba32i")
    {
        checkLayoutQualifierSupported(qualifierTypeLine, qualifierType, 310);
        qualifier.imageInternalFormat = EiifRGBA32I;
    }
    else if (qualifierType == "rgba16i")
    {
        checkLayoutQualifierSupported(qualifierTypeLine, qualifierType, 310);
        qualifier.imageInternalFormat = EiifRGBA16I;
    }
    else if (qualifierType == "rgba8i")
    {
        checkLayoutQualifierSupported(qualifierTypeLine, qualifierType, 310);
        qualifier.imageInternalFormat = EiifRGBA8I;
    }
    else if (qualifierType == "r32i")
    {
        checkLayoutQualifierSupported(qualifierTypeLine, qualifierType, 310);
        qualifier.imageInternalFormat = EiifR32I;
    }
    else if (qualifierType == "rgba32ui")
    {
        checkLayoutQualifierSupported(qualifierTypeLine, qualifierType, 310);
        qualifier.imageInternalFormat = EiifRGBA32UI;
    }
    else if (qualifierType == "rgba16ui")
    {
        checkLayoutQualifierSupported(qualifierTypeLine, qualifierType, 310);
        qualifier.imageInternalFormat = EiifRGBA16UI;
    }
    else if (qualifierType == "rgba8ui")
    {
        checkLayoutQualifierSupported(qualifierTypeLine, qualifierType, 310);
        qualifier.imageInternalFormat = EiifRGBA8UI;
    }
    else if (qualifierType == "r32ui")
    {
        checkLayoutQualifierSupported(qualifierTypeLine, qualifierType, 310);
        qualifier.imageInternalFormat = EiifR32UI;
    }
    else if (mShaderType == GL_GEOMETRY_SHADER_EXT &&
             (mShaderVersion >= 320 ||
              (checkCanUseExtension(qualifierTypeLine, TExtension::EXT_geometry_shader) &&
               checkLayoutQualifierSupported(qualifierTypeLine, qualifierType, 310))))
    {
        if (qualifierType == "points")
        {
            qualifier.primitiveType = EptPoints;
        }
        else if (qualifierType == "lines")
        {
            qualifier.primitiveType = EptLines;
        }
        else if (qualifierType == "lines_adjacency")
        {
            qualifier.primitiveType = EptLinesAdjacency;
        }
        else if (qualifierType == "triangles")
        {
            qualifier.primitiveType = EptTriangles;
        }
        else if (qualifierType == "triangles_adjacency")
        {
            qualifier.primitiveType = EptTrianglesAdjacency;
        }
        else if (qualifierType == "line_strip")
        {
            qualifier.primitiveType = EptLineStrip;
        }
        else if (qualifierType == "triangle_strip")
        {
            qualifier.primitiveType = EptTriangleStrip;
        }
        else
        {
            error(qualifierTypeLine, "invalid layout qualifier", qualifierType);
        }
    }
    else if (mShaderType == GL_TESS_EVALUATION_SHADER_EXT &&
             (mShaderVersion >= 320 ||
              (checkCanUseExtension(qualifierTypeLine, TExtension::EXT_tessellation_shader) &&
               checkLayoutQualifierSupported(qualifierTypeLine, qualifierType, 310))))
    {
        if (qualifierType == "triangles")
        {
            qualifier.tesPrimitiveType = EtetTriangles;
        }
        else if (qualifierType == "quads")
        {
            qualifier.tesPrimitiveType = EtetQuads;
        }
        else if (qualifierType == "isolines")
        {
            qualifier.tesPrimitiveType = EtetIsolines;
        }
        else if (qualifierType == "equal_spacing")
        {
            qualifier.tesVertexSpacingType = EtetEqualSpacing;
        }
        else if (qualifierType == "fractional_even_spacing")
        {
            qualifier.tesVertexSpacingType = EtetFractionalEvenSpacing;
        }
        else if (qualifierType == "fractional_odd_spacing")
        {
            qualifier.tesVertexSpacingType = EtetFractionalOddSpacing;
        }
        else if (qualifierType == "cw")
        {
            qualifier.tesOrderingType = EtetCw;
        }
        else if (qualifierType == "ccw")
        {
            qualifier.tesOrderingType = EtetCcw;
        }
        else if (qualifierType == "point_mode")
        {
            qualifier.tesPointType = EtetPointMode;
        }
        else
        {
            error(qualifierTypeLine, "invalid layout qualifier", qualifierType);
        }
    }
    else if (qualifierType == "noncoherent" && mShaderType == GL_FRAGMENT_SHADER)
    {
        if (checkCanUseOneOfExtensions(
                qualifierTypeLine, std::array<TExtension, 2u>{
                                       {TExtension::EXT_shader_framebuffer_fetch,
                                        TExtension::EXT_shader_framebuffer_fetch_non_coherent}}))
        {
            checkLayoutQualifierSupported(qualifierTypeLine, qualifierType, 100);
            qualifier.noncoherent = true;
        }
    }
    else
    {
        error(qualifierTypeLine, "invalid layout qualifier", qualifierType);
    }

    return qualifier;
}

void TParseContext::parseLocalSize(const ImmutableString &qualifierType,
                                   const TSourceLoc &qualifierTypeLine,
                                   int intValue,
                                   const TSourceLoc &intValueLine,
                                   const std::string &intValueString,
                                   size_t index,
                                   sh::WorkGroupSize *localSize)
{
    checkLayoutQualifierSupported(qualifierTypeLine, qualifierType, 310);
    if (intValue < 1)
    {
        std::stringstream reasonStream = sh::InitializeStream<std::stringstream>();
        reasonStream << "out of range: " << getWorkGroupSizeString(index) << " must be positive";
        std::string reason = reasonStream.str();
        error(intValueLine, reason.c_str(), intValueString.c_str());
    }
    (*localSize)[index] = intValue;
}

void TParseContext::parseNumViews(int intValue,
                                  const TSourceLoc &intValueLine,
                                  const std::string &intValueString,
                                  int *numViews)
{
    // This error is only specified in WebGL, but tightens unspecified behavior in the native
    // specification.
    if (intValue < 1)
    {
        error(intValueLine, "out of range: num_views must be positive", intValueString.c_str());
    }
    *numViews = intValue;
}

void TParseContext::parseInvocations(int intValue,
                                     const TSourceLoc &intValueLine,
                                     const std::string &intValueString,
                                     int *numInvocations)
{
    // Although SPEC isn't clear whether invocations can be less than 1, we add this limit because
    // it doesn't make sense to accept invocations <= 0.
    if (intValue < 1 || intValue > mMaxGeometryShaderInvocations)
    {
        error(intValueLine,
              "out of range: invocations must be in the range of [1, "
              "MAX_GEOMETRY_SHADER_INVOCATIONS_OES]",
              intValueString.c_str());
    }
    else
    {
        *numInvocations = intValue;
    }
}

void TParseContext::parseMaxVertices(int intValue,
                                     const TSourceLoc &intValueLine,
                                     const std::string &intValueString,
                                     int *maxVertices)
{
    // Although SPEC isn't clear whether max_vertices can be less than 0, we add this limit because
    // it doesn't make sense to accept max_vertices < 0.
    if (intValue < 0 || intValue > mMaxGeometryShaderMaxVertices)
    {
        error(
            intValueLine,
            "out of range: max_vertices must be in the range of [0, gl_MaxGeometryOutputVertices]",
            intValueString.c_str());
    }
    else
    {
        *maxVertices = intValue;
    }
}

void TParseContext::parseVertices(int intValue,
                                  const TSourceLoc &intValueLine,
                                  const std::string &intValueString,
                                  int *vertices)
{
    if (intValue < 1 || intValue > mMaxPatchVertices)
    {
        error(intValueLine,
              "out of range : vertices must be in the range of [1, gl_MaxPatchVertices]",
              intValueString.c_str());
    }
    else
    {
        *vertices = intValue;
    }
}

void TParseContext::parseIndexLayoutQualifier(int intValue,
                                              const TSourceLoc &intValueLine,
                                              const std::string &intValueString,
                                              int *index)
{
    // EXT_blend_func_extended specifies that most validation should happen at link time, but since
    // we're validating output variable locations at compile time, it makes sense to validate that
    // index is 0 or 1 also at compile time. Also since we use "-1" as a placeholder for unspecified
    // index, we can't accept it here.
    if (intValue < 0 || intValue > 1)
    {
        error(intValueLine, "out of range: index layout qualifier can only be 0 or 1",
              intValueString.c_str());
    }
    else
    {
        *index = intValue;
    }
}

TLayoutQualifier TParseContext::parseLayoutQualifier(const ImmutableString &qualifierType,
                                                     const TSourceLoc &qualifierTypeLine,
                                                     int intValue,
                                                     const TSourceLoc &intValueLine)
{
    TLayoutQualifier qualifier = TLayoutQualifier::Create();

    std::string intValueString = Str(intValue);

    if (qualifierType == "location")
    {
        // must check that location is non-negative
        if (intValue < 0)
        {
            error(intValueLine, "out of range: location must be non-negative",
                  intValueString.c_str());
        }
        else
        {
            qualifier.location           = intValue;
            qualifier.locationsSpecified = 1;
        }
    }
    else if (qualifierType == "binding")
    {
        checkLayoutQualifierSupported(qualifierTypeLine, qualifierType, 310);
        if (intValue < 0)
        {
            error(intValueLine, "out of range: binding must be non-negative",
                  intValueString.c_str());
        }
        else
        {
            qualifier.binding = intValue;
        }
    }
    else if (qualifierType == "offset")
    {
        checkLayoutQualifierSupported(qualifierTypeLine, qualifierType, 310);
        if (intValue < 0)
        {
            error(intValueLine, "out of range: offset must be non-negative",
                  intValueString.c_str());
        }
        else
        {
            qualifier.offset = intValue;
        }
    }
    else if (qualifierType == "local_size_x")
    {
        parseLocalSize(qualifierType, qualifierTypeLine, intValue, intValueLine, intValueString, 0u,
                       &qualifier.localSize);
    }
    else if (qualifierType == "local_size_y")
    {
        parseLocalSize(qualifierType, qualifierTypeLine, intValue, intValueLine, intValueString, 1u,
                       &qualifier.localSize);
    }
    else if (qualifierType == "local_size_z")
    {
        parseLocalSize(qualifierType, qualifierTypeLine, intValue, intValueLine, intValueString, 2u,
                       &qualifier.localSize);
    }
    else if (qualifierType == "num_views" && mShaderType == GL_VERTEX_SHADER)
    {
        if (checkCanUseOneOfExtensions(
                qualifierTypeLine, std::array<TExtension, 2u>{
                                       {TExtension::OVR_multiview, TExtension::OVR_multiview2}}))
        {
            parseNumViews(intValue, intValueLine, intValueString, &qualifier.numViews);
        }
    }
    else if (qualifierType == "invocations" && mShaderType == GL_GEOMETRY_SHADER_EXT &&
             (mShaderVersion >= 320 ||
              checkCanUseExtension(qualifierTypeLine, TExtension::EXT_geometry_shader)))
    {
        parseInvocations(intValue, intValueLine, intValueString, &qualifier.invocations);
    }
    else if (qualifierType == "max_vertices" && mShaderType == GL_GEOMETRY_SHADER_EXT &&
             (mShaderVersion >= 320 ||
              checkCanUseExtension(qualifierTypeLine, TExtension::EXT_geometry_shader)))
    {
        parseMaxVertices(intValue, intValueLine, intValueString, &qualifier.maxVertices);
    }
    else if (qualifierType == "index" && mShaderType == GL_FRAGMENT_SHADER &&
             checkCanUseExtension(qualifierTypeLine, TExtension::EXT_blend_func_extended))
    {
        parseIndexLayoutQualifier(intValue, intValueLine, intValueString, &qualifier.index);
    }
    else if (qualifierType == "vertices" && mShaderType == GL_TESS_CONTROL_SHADER_EXT &&
             (mShaderVersion >= 320 ||
              checkCanUseExtension(qualifierTypeLine, TExtension::EXT_tessellation_shader)))
    {
        parseVertices(intValue, intValueLine, intValueString, &qualifier.vertices);
    }
    else
    {
        error(qualifierTypeLine, "invalid layout qualifier", qualifierType);
    }

    return qualifier;
}

TTypeQualifierBuilder *TParseContext::createTypeQualifierBuilder(const TSourceLoc &loc)
{
    return new TTypeQualifierBuilder(
        new TStorageQualifierWrapper(symbolTable.atGlobalLevel() ? EvqGlobal : EvqTemporary, loc),
        mShaderVersion);
}

TStorageQualifierWrapper *TParseContext::parseGlobalStorageQualifier(TQualifier qualifier,
                                                                     const TSourceLoc &loc)
{
    checkIsAtGlobalLevel(loc, getQualifierString(qualifier));
    return new TStorageQualifierWrapper(qualifier, loc);
}

TStorageQualifierWrapper *TParseContext::parseVaryingQualifier(const TSourceLoc &loc)
{
    if (getShaderType() == GL_VERTEX_SHADER)
    {
        return parseGlobalStorageQualifier(EvqVaryingOut, loc);
    }
    return parseGlobalStorageQualifier(EvqVaryingIn, loc);
}

TStorageQualifierWrapper *TParseContext::parseInQualifier(const TSourceLoc &loc)
{
    if (declaringFunction())
    {
        return new TStorageQualifierWrapper(EvqIn, loc);
    }

    switch (getShaderType())
    {
        case GL_VERTEX_SHADER:
        {
            if (mShaderVersion < 300 && !anyMultiviewExtensionAvailable() &&
                !IsDesktopGLSpec(mShaderSpec))
            {
                error(loc, "storage qualifier supported in GLSL ES 3.00 and above only", "in");
            }
            return new TStorageQualifierWrapper(EvqVertexIn, loc);
        }
        case GL_FRAGMENT_SHADER:
        {
            if (mShaderVersion < 300 && !IsDesktopGLSpec(mShaderSpec))
            {
                error(loc, "storage qualifier supported in GLSL ES 3.00 and above only", "in");
            }
            return new TStorageQualifierWrapper(EvqFragmentIn, loc);
        }
        case GL_COMPUTE_SHADER:
        {
            return new TStorageQualifierWrapper(EvqComputeIn, loc);
        }
        case GL_GEOMETRY_SHADER:
        {
            return new TStorageQualifierWrapper(EvqGeometryIn, loc);
        }
        case GL_TESS_CONTROL_SHADER:
        {
            return new TStorageQualifierWrapper(EvqTessControlIn, loc);
        }
        case GL_TESS_EVALUATION_SHADER:
        {
            return new TStorageQualifierWrapper(EvqTessEvaluationIn, loc);
        }
        default:
        {
            UNREACHABLE();
            return new TStorageQualifierWrapper(EvqLast, loc);
        }
    }
}

TStorageQualifierWrapper *TParseContext::parseOutQualifier(const TSourceLoc &loc)
{
    if (declaringFunction())
    {
        return new TStorageQualifierWrapper(EvqOut, loc);
    }
    switch (getShaderType())
    {
        case GL_VERTEX_SHADER:
        {
            if (mShaderVersion < 300 && !IsDesktopGLSpec(mShaderSpec))
            {
                error(loc, "storage qualifier supported in GLSL ES 3.00 and above only", "out");
            }
            return new TStorageQualifierWrapper(EvqVertexOut, loc);
        }
        case GL_FRAGMENT_SHADER:
        {
            if (mShaderVersion < 300 && !IsDesktopGLSpec(mShaderSpec))
            {
                error(loc, "storage qualifier supported in GLSL ES 3.00 and above only", "out");
            }
            return new TStorageQualifierWrapper(EvqFragmentOut, loc);
        }
        case GL_COMPUTE_SHADER:
        {
            error(loc, "storage qualifier isn't supported in compute shaders", "out");
            return new TStorageQualifierWrapper(EvqOut, loc);
        }
        case GL_GEOMETRY_SHADER_EXT:
        {
            return new TStorageQualifierWrapper(EvqGeometryOut, loc);
        }
        case GL_TESS_CONTROL_SHADER_EXT:
        {
            return new TStorageQualifierWrapper(EvqTessControlOut, loc);
        }
        case GL_TESS_EVALUATION_SHADER_EXT:
        {
            return new TStorageQualifierWrapper(EvqTessEvaluationOut, loc);
        }
        default:
        {
            UNREACHABLE();
            return new TStorageQualifierWrapper(EvqLast, loc);
        }
    }
}

TStorageQualifierWrapper *TParseContext::parseInOutQualifier(const TSourceLoc &loc)
{
    if (!declaringFunction())
    {
        if (isExtensionEnabled(TExtension::EXT_shader_framebuffer_fetch) ||
            isExtensionEnabled(TExtension::EXT_shader_framebuffer_fetch_non_coherent))
        {
            return new TStorageQualifierWrapper(EvqFragmentInOut, loc);
        }

        error(loc,
              "invalid qualifier: can be used with either function parameters or the variables for "
              "fetching input attachment data",
              "inout");
    }
    return new TStorageQualifierWrapper(EvqInOut, loc);
}

TLayoutQualifier TParseContext::joinLayoutQualifiers(TLayoutQualifier leftQualifier,
                                                     TLayoutQualifier rightQualifier,
                                                     const TSourceLoc &rightQualifierLocation)
{
    return sh::JoinLayoutQualifiers(leftQualifier, rightQualifier, rightQualifierLocation,
                                    mDiagnostics);
}

TDeclarator *TParseContext::parseStructDeclarator(const ImmutableString &identifier,
                                                  const TSourceLoc &loc)
{
    checkIsNotReserved(loc, identifier);
    return new TDeclarator(identifier, loc);
}

TDeclarator *TParseContext::parseStructArrayDeclarator(const ImmutableString &identifier,
                                                       const TSourceLoc &loc,
                                                       const TVector<unsigned int> *arraySizes)
{
    checkIsNotReserved(loc, identifier);
    return new TDeclarator(identifier, arraySizes, loc);
}

void TParseContext::checkDoesNotHaveDuplicateFieldName(const TFieldList::const_iterator begin,
                                                       const TFieldList::const_iterator end,
                                                       const ImmutableString &name,
                                                       const TSourceLoc &location)
{
    for (auto fieldIter = begin; fieldIter != end; ++fieldIter)
    {
        if ((*fieldIter)->name() == name)
        {
            error(location, "duplicate field name in structure", name);
        }
    }
}

TFieldList *TParseContext::addStructFieldList(TFieldList *fields, const TSourceLoc &location)
{
    for (TFieldList::const_iterator fieldIter = fields->begin(); fieldIter != fields->end();
         ++fieldIter)
    {
        checkDoesNotHaveDuplicateFieldName(fields->begin(), fieldIter, (*fieldIter)->name(),
                                           location);
    }
    return fields;
}

TFieldList *TParseContext::combineStructFieldLists(TFieldList *processedFields,
                                                   const TFieldList *newlyAddedFields,
                                                   const TSourceLoc &location)
{
    for (TField *field : *newlyAddedFields)
    {
        checkDoesNotHaveDuplicateFieldName(processedFields->begin(), processedFields->end(),
                                           field->name(), location);
        processedFields->push_back(field);
    }
    return processedFields;
}

TFieldList *TParseContext::addStructDeclaratorListWithQualifiers(
    const TTypeQualifierBuilder &typeQualifierBuilder,
    TPublicType *typeSpecifier,
    const TDeclaratorList *declaratorList)
{
    TTypeQualifier typeQualifier = typeQualifierBuilder.getVariableTypeQualifier(mDiagnostics);

    typeSpecifier->qualifier       = typeQualifier.qualifier;
    typeSpecifier->layoutQualifier = typeQualifier.layoutQualifier;
    typeSpecifier->memoryQualifier = typeQualifier.memoryQualifier;
    typeSpecifier->invariant       = typeQualifier.invariant;
    typeSpecifier->precise         = typeQualifier.precise;
    if (typeQualifier.precision != EbpUndefined)
    {
        typeSpecifier->precision = typeQualifier.precision;
    }
    return addStructDeclaratorList(*typeSpecifier, declaratorList);
}

TFieldList *TParseContext::addStructDeclaratorList(const TPublicType &typeSpecifier,
                                                   const TDeclaratorList *declaratorList)
{
    checkPrecisionSpecified(typeSpecifier.getLine(), typeSpecifier.precision,
                            typeSpecifier.getBasicType());

    checkIsNonVoid(typeSpecifier.getLine(), (*declaratorList)[0]->name(),
                   typeSpecifier.getBasicType());

    checkWorkGroupSizeIsNotSpecified(typeSpecifier.getLine(), typeSpecifier.layoutQualifier);
    checkEarlyFragmentTestsIsNotSpecified(typeSpecifier.getLine(),
                                          typeSpecifier.layoutQualifier.earlyFragmentTests);
    checkNoncoherentIsNotSpecified(typeSpecifier.getLine(),
                                   typeSpecifier.layoutQualifier.noncoherent);

    TFieldList *fieldList = new TFieldList();

    for (const TDeclarator *declarator : *declaratorList)
    {
        TType *type = new TType(typeSpecifier);
        if (declarator->isArray())
        {
            // Don't allow arrays of arrays in ESSL < 3.10.
            checkArrayElementIsNotArray(typeSpecifier.getLine(), typeSpecifier);
            type->makeArrays(*declarator->arraySizes());
        }

        TField *field =
            new TField(type, declarator->name(), declarator->line(), SymbolType::UserDefined);
        checkIsBelowStructNestingLimit(typeSpecifier.getLine(), *field);
        fieldList->push_back(field);
    }

    return fieldList;
}

TTypeSpecifierNonArray TParseContext::addStructure(const TSourceLoc &structLine,
                                                   const TSourceLoc &nameLine,
                                                   const ImmutableString &structName,
                                                   TFieldList *fieldList)
{
    SymbolType structSymbolType = SymbolType::UserDefined;
    if (structName.empty())
    {
        structSymbolType = SymbolType::Empty;
    }
    TStructure *structure = new TStructure(&symbolTable, structName, fieldList, structSymbolType);

    // Store a bool in the struct if we're at global scope, to allow us to
    // skip the local struct scoping workaround in HLSL.
    structure->setAtGlobalScope(symbolTable.atGlobalLevel());

    if (structSymbolType != SymbolType::Empty)
    {
        checkIsNotReserved(nameLine, structName);
        if (!symbolTable.declare(structure))
        {
            error(nameLine, "redefinition of a struct", structName);
        }
    }

    // ensure we do not specify any storage qualifiers on the struct members
    for (unsigned int typeListIndex = 0; typeListIndex < fieldList->size(); typeListIndex++)
    {
        TField &field              = *(*fieldList)[typeListIndex];
        const TQualifier qualifier = field.type()->getQualifier();
        switch (qualifier)
        {
            case EvqGlobal:
            case EvqTemporary:
                break;
            default:
                error(field.line(), "invalid qualifier on struct member",
                      getQualifierString(qualifier));
                break;
        }
        if (field.type()->isInvariant())
        {
            error(field.line(), "invalid qualifier on struct member", "invariant");
        }
        // ESSL 3.10 section 4.1.8 -- atomic_uint or images are not allowed as structure member.
        if (IsImage(field.type()->getBasicType()) || IsAtomicCounter(field.type()->getBasicType()))
        {
            error(field.line(), "disallowed type in struct", field.type()->getBasicString());
        }

        checkIsNotUnsizedArray(field.line(), "array members of structs must specify a size",
                               field.name(), field.type());

        checkMemoryQualifierIsNotSpecified(field.type()->getMemoryQualifier(), field.line());

        checkIndexIsNotSpecified(field.line(), field.type()->getLayoutQualifier().index);

        checkBindingIsNotSpecified(field.line(), field.type()->getLayoutQualifier().binding);

        checkLocationIsNotSpecified(field.line(), field.type()->getLayoutQualifier());
    }

    TTypeSpecifierNonArray typeSpecifierNonArray;
    typeSpecifierNonArray.initializeStruct(structure, true, structLine);
    exitStructDeclaration();

    return typeSpecifierNonArray;
}

TIntermSwitch *TParseContext::addSwitch(TIntermTyped *init,
                                        TIntermBlock *statementList,
                                        const TSourceLoc &loc)
{
    TBasicType switchType = init->getBasicType();
    if ((switchType != EbtInt && switchType != EbtUInt) || init->isMatrix() || init->isArray() ||
        init->isVector())
    {
        error(init->getLine(), "init-expression in a switch statement must be a scalar integer",
              "switch");
        return nullptr;
    }

    ASSERT(statementList);
    if (!ValidateSwitchStatementList(switchType, mDiagnostics, statementList, loc))
    {
        ASSERT(mDiagnostics->numErrors() > 0);
        return nullptr;
    }

    markStaticReadIfSymbol(init);
    TIntermSwitch *node = new TIntermSwitch(init, statementList);
    node->setLine(loc);
    return node;
}

TIntermCase *TParseContext::addCase(TIntermTyped *condition, const TSourceLoc &loc)
{
    if (mSwitchNestingLevel == 0)
    {
        error(loc, "case labels need to be inside switch statements", "case");
        return nullptr;
    }
    if (condition == nullptr)
    {
        error(loc, "case label must have a condition", "case");
        return nullptr;
    }
    if ((condition->getBasicType() != EbtInt && condition->getBasicType() != EbtUInt) ||
        condition->isMatrix() || condition->isArray() || condition->isVector())
    {
        error(condition->getLine(), "case label must be a scalar integer", "case");
    }
    TIntermConstantUnion *conditionConst = condition->getAsConstantUnion();
    // ANGLE should be able to fold any EvqConst expressions resulting in an integer - but to be
    // safe against corner cases we still check for conditionConst. Some interpretations of the
    // spec have allowed constant expressions with side effects - like array length() method on a
    // non-constant array.
    if (condition->getQualifier() != EvqConst || conditionConst == nullptr)
    {
        error(condition->getLine(), "case label must be constant", "case");
    }
    TIntermCase *node = new TIntermCase(condition);
    node->setLine(loc);
    return node;
}

TIntermCase *TParseContext::addDefault(const TSourceLoc &loc)
{
    if (mSwitchNestingLevel == 0)
    {
        error(loc, "default labels need to be inside switch statements", "default");
        return nullptr;
    }
    TIntermCase *node = new TIntermCase(nullptr);
    node->setLine(loc);
    return node;
}

TIntermTyped *TParseContext::createUnaryMath(TOperator op,
                                             TIntermTyped *child,
                                             const TSourceLoc &loc,
                                             const TFunction *func)
{
    ASSERT(child != nullptr);

    switch (op)
    {
        case EOpLogicalNot:
            if (child->getBasicType() != EbtBool || child->isMatrix() || child->isArray() ||
                child->isVector())
            {
                unaryOpError(loc, GetOperatorString(op), child->getType());
                return nullptr;
            }
            break;
        case EOpBitwiseNot:
            if ((child->getBasicType() != EbtInt && child->getBasicType() != EbtUInt) ||
                child->isMatrix() || child->isArray())
            {
                unaryOpError(loc, GetOperatorString(op), child->getType());
                return nullptr;
            }
            break;
        case EOpPostIncrement:
        case EOpPreIncrement:
        case EOpPostDecrement:
        case EOpPreDecrement:
        case EOpNegative:
        case EOpPositive:
            if (child->getBasicType() == EbtStruct || child->isInterfaceBlock() ||
                child->getBasicType() == EbtBool || child->isArray() ||
                child->getBasicType() == EbtVoid || IsOpaqueType(child->getBasicType()))
            {
                unaryOpError(loc, GetOperatorString(op), child->getType());
                return nullptr;
            }
            break;
        // Operators for built-ins are already type checked against their prototype.
        default:
            break;
    }

    if (child->getMemoryQualifier().writeonly)
    {
        unaryOpError(loc, GetOperatorString(op), child->getType());
        return nullptr;
    }

    markStaticReadIfSymbol(child);
    TIntermUnary *node = new TIntermUnary(op, child, func);
    node->setLine(loc);

    return node->fold(mDiagnostics);
}

TIntermTyped *TParseContext::addUnaryMath(TOperator op, TIntermTyped *child, const TSourceLoc &loc)
{
    ASSERT(op != EOpNull);
    TIntermTyped *node = createUnaryMath(op, child, loc, nullptr);
    if (node == nullptr)
    {
        return child;
    }
    return node;
}

TIntermTyped *TParseContext::addUnaryMathLValue(TOperator op,
                                                TIntermTyped *child,
                                                const TSourceLoc &loc)
{
    checkCanBeLValue(loc, GetOperatorString(op), child);
    return addUnaryMath(op, child, loc);
}

TIntermTyped *TParseContext::expressionOrFoldedResult(TIntermTyped *expression)
{
    // If we can, we should return the folded version of the expression for subsequent parsing. This
    // enables folding the containing expression during parsing as well, instead of the separate
    // FoldExpressions() step where folding nested expressions requires multiple full AST
    // traversals.

    // Even if folding fails the fold() functions return some node representing the expression,
    // typically the original node. So "folded" can be assumed to be non-null.
    TIntermTyped *folded = expression->fold(mDiagnostics);
    ASSERT(folded != nullptr);
    if (folded->getQualifier() == expression->getQualifier())
    {
        // We need this expression to have the correct qualifier when validating the consuming
        // expression. So we can only return the folded node from here in case it has the same
        // qualifier as the original expression. In this kind of a cases the qualifier of the folded
        // node is EvqConst, whereas the qualifier of the expression is EvqTemporary:
        //  1. (true ? 1.0 : non_constant)
        //  2. (non_constant, 1.0)
        return folded;
    }
    return expression;
}

bool TParseContext::binaryOpCommonCheck(TOperator op,
                                        TIntermTyped *left,
                                        TIntermTyped *right,
                                        const TSourceLoc &loc)
{
    // Check opaque types are not allowed to be operands in expressions other than array indexing
    // and structure member selection.
    if (IsOpaqueType(left->getBasicType()) || IsOpaqueType(right->getBasicType()))
    {
        switch (op)
        {
            case EOpIndexDirect:
            case EOpIndexIndirect:
                break;

            default:
                ASSERT(op != EOpIndexDirectStruct);
                error(loc, "Invalid operation for variables with an opaque type",
                      GetOperatorString(op));
                return false;
        }
    }

    if (right->getMemoryQualifier().writeonly)
    {
        error(loc, "Invalid operation for variables with writeonly", GetOperatorString(op));
        return false;
    }

    if (left->getMemoryQualifier().writeonly)
    {
        switch (op)
        {
            case EOpAssign:
            case EOpInitialize:
            case EOpIndexDirect:
            case EOpIndexIndirect:
            case EOpIndexDirectStruct:
            case EOpIndexDirectInterfaceBlock:
                break;
            default:
                error(loc, "Invalid operation for variables with writeonly", GetOperatorString(op));
                return false;
        }
    }

    if (left->getType().getStruct() || right->getType().getStruct())
    {
        switch (op)
        {
            case EOpIndexDirectStruct:
                ASSERT(left->getType().getStruct());
                break;
            case EOpEqual:
            case EOpNotEqual:
            case EOpAssign:
            case EOpInitialize:
                if (left->getType() != right->getType())
                {
                    return false;
                }
                break;
            default:
                error(loc, "Invalid operation for structs", GetOperatorString(op));
                return false;
        }
    }

    if (left->isInterfaceBlock() || right->isInterfaceBlock())
    {
        switch (op)
        {
            case EOpIndexDirectInterfaceBlock:
                ASSERT(left->getType().getInterfaceBlock());
                break;
            default:
                error(loc, "Invalid operation for interface blocks", GetOperatorString(op));
                return false;
        }
    }

    if (left->isArray() != right->isArray())
    {
        error(loc, "array / non-array mismatch", GetOperatorString(op));
        return false;
    }

    if (left->isArray())
    {
        ASSERT(right->isArray());
        if (mShaderVersion < 300)
        {
            error(loc, "Invalid operation for arrays", GetOperatorString(op));
            return false;
        }

        switch (op)
        {
            case EOpEqual:
            case EOpNotEqual:
            case EOpAssign:
            case EOpInitialize:
                break;
            default:
                error(loc, "Invalid operation for arrays", GetOperatorString(op));
                return false;
        }
        // At this point, size of implicitly sized arrays should be resolved.
        if (left->getType().getArraySizes() != right->getType().getArraySizes())
        {
            error(loc, "array size mismatch", GetOperatorString(op));
            return false;
        }
    }

    // Check ops which require integer / ivec parameters
    bool isBitShift = false;
    switch (op)
    {
        case EOpBitShiftLeft:
        case EOpBitShiftRight:
        case EOpBitShiftLeftAssign:
        case EOpBitShiftRightAssign:
            // Unsigned can be bit-shifted by signed and vice versa, but we need to
            // check that the basic type is an integer type.
            isBitShift = true;
            if (!IsInteger(left->getBasicType()) || !IsInteger(right->getBasicType()))
            {
                return false;
            }
            break;
        case EOpBitwiseAnd:
        case EOpBitwiseXor:
        case EOpBitwiseOr:
        case EOpBitwiseAndAssign:
        case EOpBitwiseXorAssign:
        case EOpBitwiseOrAssign:
            // It is enough to check the type of only one operand, since later it
            // is checked that the operand types match.
            if (!IsInteger(left->getBasicType()))
            {
                return false;
            }
            break;
        default:
            break;
    }

    ImplicitTypeConversion conversion = GetConversion(left->getBasicType(), right->getBasicType());

    // Implicit type casting only supported for GL shaders
    if (!isBitShift && conversion != ImplicitTypeConversion::Same &&
        (!IsDesktopGLSpec(mShaderSpec) || !IsValidImplicitConversion(conversion, op)))
    {
        return false;
    }

    // Check that:
    // 1. Type sizes match exactly on ops that require that.
    // 2. Restrictions for structs that contain arrays or samplers are respected.
    // 3. Arithmetic op type dimensionality restrictions for ops other than multiply are respected.
    switch (op)
    {
        case EOpAssign:
        case EOpInitialize:
        case EOpEqual:
        case EOpNotEqual:
            // ESSL 1.00 sections 5.7, 5.8, 5.9
            if (mShaderVersion < 300 && left->getType().isStructureContainingArrays())
            {
                error(loc, "undefined operation for structs containing arrays",
                      GetOperatorString(op));
                return false;
            }
            // Samplers as l-values are disallowed also in ESSL 3.00, see section 4.1.7,
            // we interpret the spec so that this extends to structs containing samplers,
            // similarly to ESSL 1.00 spec.
            if ((mShaderVersion < 300 || op == EOpAssign || op == EOpInitialize) &&
                left->getType().isStructureContainingSamplers())
            {
                error(loc, "undefined operation for structs containing samplers",
                      GetOperatorString(op));
                return false;
            }

            if ((left->getNominalSize() != right->getNominalSize()) ||
                (left->getSecondarySize() != right->getSecondarySize()))
            {
                error(loc, "dimension mismatch", GetOperatorString(op));
                return false;
            }
            break;
        case EOpLessThan:
        case EOpGreaterThan:
        case EOpLessThanEqual:
        case EOpGreaterThanEqual:
            if (!left->isScalar() || !right->isScalar())
            {
                error(loc, "comparison operator only defined for scalars", GetOperatorString(op));
                return false;
            }
            break;
        case EOpAdd:
        case EOpSub:
        case EOpDiv:
        case EOpIMod:
        case EOpBitShiftLeft:
        case EOpBitShiftRight:
        case EOpBitwiseAnd:
        case EOpBitwiseXor:
        case EOpBitwiseOr:
        case EOpAddAssign:
        case EOpSubAssign:
        case EOpDivAssign:
        case EOpIModAssign:
        case EOpBitShiftLeftAssign:
        case EOpBitShiftRightAssign:
        case EOpBitwiseAndAssign:
        case EOpBitwiseXorAssign:
        case EOpBitwiseOrAssign:
            if ((left->isMatrix() && right->isVector()) || (left->isVector() && right->isMatrix()))
            {
                return false;
            }

            // Are the sizes compatible?
            if (left->getNominalSize() != right->getNominalSize() ||
                left->getSecondarySize() != right->getSecondarySize())
            {
                // If the nominal sizes of operands do not match:
                // One of them must be a scalar.
                if (!left->isScalar() && !right->isScalar())
                    return false;

                // In the case of compound assignment other than multiply-assign,
                // the right side needs to be a scalar. Otherwise a vector/matrix
                // would be assigned to a scalar. A scalar can't be shifted by a
                // vector either.
                if (!right->isScalar() &&
                    (IsAssignment(op) || op == EOpBitShiftLeft || op == EOpBitShiftRight))
                    return false;
            }
            break;
        default:
            break;
    }

    return true;
}

bool TParseContext::isMultiplicationTypeCombinationValid(TOperator op,
                                                         const TType &left,
                                                         const TType &right)
{
    switch (op)
    {
        case EOpMul:
        case EOpMulAssign:
            return left.getNominalSize() == right.getNominalSize() &&
                   left.getSecondarySize() == right.getSecondarySize();
        case EOpVectorTimesScalar:
            return true;
        case EOpVectorTimesScalarAssign:
            ASSERT(!left.isMatrix() && !right.isMatrix());
            return left.isVector() && !right.isVector();
        case EOpVectorTimesMatrix:
            return left.getNominalSize() == right.getRows();
        case EOpVectorTimesMatrixAssign:
            ASSERT(!left.isMatrix() && right.isMatrix());
            return left.isVector() && left.getNominalSize() == right.getRows() &&
                   left.getNominalSize() == right.getCols();
        case EOpMatrixTimesVector:
            return left.getCols() == right.getNominalSize();
        case EOpMatrixTimesScalar:
            return true;
        case EOpMatrixTimesScalarAssign:
            ASSERT(left.isMatrix() && !right.isMatrix());
            return !right.isVector();
        case EOpMatrixTimesMatrix:
            return left.getCols() == right.getRows();
        case EOpMatrixTimesMatrixAssign:
            ASSERT(left.isMatrix() && right.isMatrix());
            // We need to check two things:
            // 1. The matrix multiplication step is valid.
            // 2. The result will have the same number of columns as the lvalue.
            return left.getCols() == right.getRows() && left.getCols() == right.getCols();

        default:
            UNREACHABLE();
            return false;
    }
}

TIntermTyped *TParseContext::addBinaryMathInternal(TOperator op,
                                                   TIntermTyped *left,
                                                   TIntermTyped *right,
                                                   const TSourceLoc &loc)
{
    if (!binaryOpCommonCheck(op, left, right, loc))
        return nullptr;

    switch (op)
    {
        case EOpEqual:
        case EOpNotEqual:
        case EOpLessThan:
        case EOpGreaterThan:
        case EOpLessThanEqual:
        case EOpGreaterThanEqual:
            break;
        case EOpLogicalOr:
        case EOpLogicalXor:
        case EOpLogicalAnd:
            ASSERT(!left->isArray() && !right->isArray() && !left->getType().getStruct() &&
                   !right->getType().getStruct());
            if (left->getBasicType() != EbtBool || !left->isScalar() || !right->isScalar())
            {
                return nullptr;
            }
            // Basic types matching should have been already checked.
            ASSERT(right->getBasicType() == EbtBool);
            break;
        case EOpAdd:
        case EOpSub:
        case EOpDiv:
        case EOpMul:
            ASSERT(!left->isArray() && !right->isArray() && !left->getType().getStruct() &&
                   !right->getType().getStruct());
            if (left->getBasicType() == EbtBool)
            {
                return nullptr;
            }
            break;
        case EOpIMod:
            ASSERT(!left->isArray() && !right->isArray() && !left->getType().getStruct() &&
                   !right->getType().getStruct());
            // Note that this is only for the % operator, not for mod()
            if (left->getBasicType() == EbtBool || left->getBasicType() == EbtFloat)
            {
                return nullptr;
            }
            break;
        default:
            break;
    }

    if (op == EOpMul)
    {
        op = TIntermBinary::GetMulOpBasedOnOperands(left->getType(), right->getType());
        if (!isMultiplicationTypeCombinationValid(op, left->getType(), right->getType()))
        {
            return nullptr;
        }
    }

    TIntermBinary *node = new TIntermBinary(op, left, right);
    ASSERT(op != EOpAssign);
    markStaticReadIfSymbol(left);
    markStaticReadIfSymbol(right);
    node->setLine(loc);
    return expressionOrFoldedResult(node);
}

TIntermTyped *TParseContext::addBinaryMath(TOperator op,
                                           TIntermTyped *left,
                                           TIntermTyped *right,
                                           const TSourceLoc &loc)
{
    TIntermTyped *node = addBinaryMathInternal(op, left, right, loc);
    if (node == 0)
    {
        binaryOpError(loc, GetOperatorString(op), left->getType(), right->getType());
        return left;
    }
    return node;
}

TIntermTyped *TParseContext::addBinaryMathBooleanResult(TOperator op,
                                                        TIntermTyped *left,
                                                        TIntermTyped *right,
                                                        const TSourceLoc &loc)
{
    TIntermTyped *node = addBinaryMathInternal(op, left, right, loc);
    if (node == nullptr)
    {
        binaryOpError(loc, GetOperatorString(op), left->getType(), right->getType());
        node = CreateBoolNode(false);
        node->setLine(loc);
    }
    return node;
}

TIntermTyped *TParseContext::addAssign(TOperator op,
                                       TIntermTyped *left,
                                       TIntermTyped *right,
                                       const TSourceLoc &loc)
{
    checkCanBeLValue(loc, "assign", left);
    TIntermBinary *node = nullptr;
    if (binaryOpCommonCheck(op, left, right, loc))
    {
        if (op == EOpMulAssign)
        {
            op = TIntermBinary::GetMulAssignOpBasedOnOperands(left->getType(), right->getType());
            if (isMultiplicationTypeCombinationValid(op, left->getType(), right->getType()))
            {
                node = new TIntermBinary(op, left, right);
            }
        }
        else
        {
            node = new TIntermBinary(op, left, right);
        }
    }
    if (node == nullptr)
    {
        assignError(loc, "assign", left->getType(), right->getType());
        return left;
    }
    if (op != EOpAssign)
    {
        markStaticReadIfSymbol(left);
    }
    markStaticReadIfSymbol(right);
    node->setLine(loc);
    return node;
}

TIntermTyped *TParseContext::addComma(TIntermTyped *left,
                                      TIntermTyped *right,
                                      const TSourceLoc &loc)
{
    // WebGL2 section 5.26, the following results in an error:
    // "Sequence operator applied to void, arrays, or structs containing arrays"
    if (mShaderSpec == SH_WEBGL2_SPEC &&
        (left->isArray() || left->getBasicType() == EbtVoid ||
         left->getType().isStructureContainingArrays() || right->isArray() ||
         right->getBasicType() == EbtVoid || right->getType().isStructureContainingArrays()))
    {
        error(loc,
              "sequence operator is not allowed for void, arrays, or structs containing arrays",
              ",");
    }

    TIntermBinary *commaNode = TIntermBinary::CreateComma(left, right, mShaderVersion);
    markStaticReadIfSymbol(left);
    markStaticReadIfSymbol(right);
    commaNode->setLine(loc);

    return expressionOrFoldedResult(commaNode);
}

TIntermBranch *TParseContext::addBranch(TOperator op, const TSourceLoc &loc)
{
    switch (op)
    {
        case EOpContinue:
            if (mLoopNestingLevel <= 0)
            {
                error(loc, "continue statement only allowed in loops", "");
            }
            break;
        case EOpBreak:
            if (mLoopNestingLevel <= 0 && mSwitchNestingLevel <= 0)
            {
                error(loc, "break statement only allowed in loops and switch statements", "");
            }
            break;
        case EOpReturn:
            if (mCurrentFunctionType->getBasicType() != EbtVoid)
            {
                error(loc, "non-void function must return a value", "return");
            }
            break;
        case EOpKill:
            if (mShaderType != GL_FRAGMENT_SHADER)
            {
                error(loc, "discard supported in fragment shaders only", "discard");
            }
            break;
        default:
            UNREACHABLE();
            break;
    }
    return addBranch(op, nullptr, loc);
}

TIntermBranch *TParseContext::addBranch(TOperator op,
                                        TIntermTyped *expression,
                                        const TSourceLoc &loc)
{
    if (expression != nullptr)
    {
        markStaticReadIfSymbol(expression);
        ASSERT(op == EOpReturn);
        mFunctionReturnsValue = true;
        if (mCurrentFunctionType->getBasicType() == EbtVoid)
        {
            error(loc, "void function cannot return a value", "return");
        }
        else if (*mCurrentFunctionType != expression->getType())
        {
            error(loc, "function return is not matching type:", "return");
        }
    }
    TIntermBranch *node = new TIntermBranch(op, expression);
    node->setLine(loc);
    return node;
}

void TParseContext::appendStatement(TIntermBlock *block, TIntermNode *statement)
{
    if (statement != nullptr)
    {
        markStaticReadIfSymbol(statement);
        block->appendStatement(statement);
    }
}

void TParseContext::checkTextureGather(TIntermAggregate *functionCall)
{
    ASSERT(functionCall->getOp() == EOpCallBuiltInFunction);
    const TFunction *func = functionCall->getFunction();
    if (BuiltInGroup::isTextureGather(func))
    {
        bool isTextureGatherOffsetOrOffsets =
            BuiltInGroup::isTextureGatherOffset(func) || BuiltInGroup::isTextureGatherOffsets(func);
        TIntermNode *componentNode = nullptr;
        TIntermSequence *arguments = functionCall->getSequence();
        ASSERT(arguments->size() >= 2u && arguments->size() <= 4u);
        const TIntermTyped *sampler = arguments->front()->getAsTyped();
        ASSERT(sampler != nullptr);
        switch (sampler->getBasicType())
        {
            case EbtSampler2D:
            case EbtISampler2D:
            case EbtUSampler2D:
            case EbtSampler2DArray:
            case EbtISampler2DArray:
            case EbtUSampler2DArray:
                if ((!isTextureGatherOffsetOrOffsets && arguments->size() == 3u) ||
                    (isTextureGatherOffsetOrOffsets && arguments->size() == 4u))
                {
                    componentNode = arguments->back();
                }
                break;
            case EbtSamplerCube:
            case EbtISamplerCube:
            case EbtUSamplerCube:
                ASSERT(!isTextureGatherOffsetOrOffsets);
                if (arguments->size() == 3u)
                {
                    componentNode = arguments->back();
                }
                break;
            case EbtSampler2DShadow:
            case EbtSampler2DArrayShadow:
            case EbtSamplerCubeShadow:
                break;
            default:
                UNREACHABLE();
                break;
        }
        if (componentNode)
        {
            const TIntermConstantUnion *componentConstantUnion =
                componentNode->getAsConstantUnion();
            if (componentNode->getAsTyped()->getQualifier() != EvqConst || !componentConstantUnion)
            {
                error(functionCall->getLine(), "Texture component must be a constant expression",
                      func->name());
            }
            else
            {
                int component = componentConstantUnion->getIConst(0);
                if (component < 0 || component > 3)
                {
                    error(functionCall->getLine(), "Component must be in the range [0;3]",
                          func->name());
                }
            }
        }
    }
}

void TParseContext::checkTextureOffset(TIntermAggregate *functionCall)
{
    ASSERT(functionCall->getOp() == EOpCallBuiltInFunction);
    const TFunction *func      = functionCall->getFunction();
    TIntermNode *offset        = nullptr;
    TIntermSequence *arguments = functionCall->getSequence();

    if (BuiltInGroup::isTextureOffsetNoBias(func) ||
        BuiltInGroup::isTextureGatherOffsetNoComp(func) ||
        BuiltInGroup::isTextureGatherOffsetsNoComp(func))
    {
        offset = arguments->back();
    }
    else if (BuiltInGroup::isTextureOffsetBias(func) ||
             BuiltInGroup::isTextureGatherOffsetComp(func) ||
             BuiltInGroup::isTextureGatherOffsetsComp(func))
    {
        // A bias or comp parameter follows the offset parameter.
        ASSERT(arguments->size() >= 3);
        offset = (*arguments)[2];
    }

    // If not one of the above built-ins, there's nothing to do here.
    if (offset == nullptr)
    {
        return;
    }

    bool isTextureGatherOffset             = BuiltInGroup::isTextureGatherOffset(func);
    bool isTextureGatherOffsets            = BuiltInGroup::isTextureGatherOffsets(func);
    bool useTextureGatherOffsetConstraints = isTextureGatherOffset || isTextureGatherOffsets;

    int minOffsetValue =
        useTextureGatherOffsetConstraints ? mMinProgramTextureGatherOffset : mMinProgramTexelOffset;
    int maxOffsetValue =
        useTextureGatherOffsetConstraints ? mMaxProgramTextureGatherOffset : mMaxProgramTexelOffset;

    if (isTextureGatherOffsets)
    {
        // If textureGatherOffsets, the offsets parameter is an array, which is expected as an
        // aggregate constructor node.
        TIntermAggregate *offsetAggregate = offset->getAsAggregate();
        const TConstantUnion *offsetValues =
            offsetAggregate ? offsetAggregate->getConstantValue() : nullptr;

        if (offsetValues == nullptr)
        {
            error(functionCall->getLine(), "Texture offsets must be a constant expression",
                  func->name());
            return;
        }

        constexpr unsigned int kOffsetsCount = 4;
        const TType &offsetAggregateType     = offsetAggregate->getType();
        if (offsetAggregateType.getNumArraySizes() != 1 ||
            offsetAggregateType.getArraySizes()[0] != kOffsetsCount)
        {
            error(functionCall->getLine(), "Texture offsets must be an array of 4 elements",
                  func->name());
            return;
        }

        TIntermNode *firstOffset = offsetAggregate->getSequence()->front();
        size_t size              = firstOffset->getAsTyped()->getType().getObjectSize();
        for (unsigned int i = 0; i < kOffsetsCount; ++i)
        {
            checkSingleTextureOffset(offset->getLine(), &offsetValues[i * size], size,
                                     minOffsetValue, maxOffsetValue);
        }
    }
    else
    {
        // If textureOffset or textureGatherOffset, the offset is expected to be found as a constant
        // union.
        TIntermConstantUnion *offsetConstantUnion = offset->getAsConstantUnion();

        // ES3.2 or ES3.1's EXT_gpu_shader5 allow non-const offsets to be passed to
        // textureGatherOffset.
        bool textureGatherOffsetMustBeConst =
            mShaderVersion <= 310 && !isExtensionEnabled(TExtension::EXT_gpu_shader5);

        bool isOffsetConst =
            offset->getAsTyped()->getQualifier() == EvqConst && offsetConstantUnion != nullptr;
        bool offsetMustBeConst = !isTextureGatherOffset || textureGatherOffsetMustBeConst;

        if (!isOffsetConst && offsetMustBeConst)
        {
            error(functionCall->getLine(), "Texture offset must be a constant expression",
                  func->name());
            return;
        }

        // We cannot verify non-constant offsets to textureGatherOffset.
        if (offsetConstantUnion == nullptr)
        {
            ASSERT(!offsetMustBeConst);
            return;
        }

        size_t size                  = offsetConstantUnion->getType().getObjectSize();
        const TConstantUnion *values = offsetConstantUnion->getConstantValue();
        checkSingleTextureOffset(offset->getLine(), values, size, minOffsetValue, maxOffsetValue);
    }
}

void TParseContext::checkSingleTextureOffset(const TSourceLoc &line,
                                             const TConstantUnion *values,
                                             size_t size,
                                             int minOffsetValue,
                                             int maxOffsetValue)
{
    for (size_t i = 0u; i < size; ++i)
    {
        ASSERT(values[i].getType() == EbtInt);
        int offsetValue = values[i].getIConst();
        if (offsetValue > maxOffsetValue || offsetValue < minOffsetValue)
        {
            std::stringstream tokenStream = sh::InitializeStream<std::stringstream>();
            tokenStream << offsetValue;
            std::string token = tokenStream.str();
            error(line, "Texture offset value out of valid range", token.c_str());
        }
    }
}

void TParseContext::checkInterpolationFS(TIntermAggregate *functionCall)
{
    const TFunction *func = functionCall->getFunction();
    if (!BuiltInGroup::isInterpolationFS(func))
    {
        return;
    }

    TIntermTyped *arg0 = nullptr;

    if (functionCall->getAsAggregate())
    {
        const TIntermSequence *argp = functionCall->getSequence();
        if (argp->size() > 0)
            arg0 = (*argp)[0]->getAsTyped();
    }
    else
    {
        assert(functionCall->getAsUnaryNode());
        arg0 = functionCall->getAsUnaryNode()->getOperand();
    }

    // Make sure the first argument is an interpolant, or an array element of an interpolant
    if (!IsVaryingIn(arg0->getType().getQualifier()))
    {
        // It might still be an array element.
        const TIntermTyped *base = FindLValueBase(arg0);

        if (base == nullptr || (!IsVaryingIn(base->getType().getQualifier())))
            error(arg0->getLine(),
                  "first argument must be an interpolant, or interpolant-array element",
                  func->name());
    }
}

void TParseContext::checkAtomicMemoryBuiltinFunctions(TIntermAggregate *functionCall)
{
    const TFunction *func = functionCall->getFunction();
    if (BuiltInGroup::isAtomicMemory(func))
    {
        ASSERT(IsAtomicFunction(functionCall->getOp()));
        TIntermSequence *arguments = functionCall->getSequence();
        TIntermTyped *memNode      = (*arguments)[0]->getAsTyped();

        if (IsBufferOrSharedVariable(memNode))
        {
            return;
        }

        while (memNode->getAsBinaryNode() || memNode->getAsSwizzleNode())
        {
            // Child 0 is "left" if binary, and the expression being swizzled if swizzle.
            // Note: we don't need to check that the binary operation is one of EOp*Index*, as any
            // other operation will result in a temp value which cannot be passed to this
            // out/inout parameter anyway.
            memNode = memNode->getChildNode(0)->getAsTyped();
            if (IsBufferOrSharedVariable(memNode))
            {
                return;
            }
        }

        error(memNode->getLine(),
              "The value passed to the mem argument of an atomic memory function does not "
              "correspond to a buffer or shared variable.",
              func->name());
    }
}

// GLSL ES 3.10 Revision 4, 4.9 Memory Access Qualifiers
void TParseContext::checkImageMemoryAccessForBuiltinFunctions(TIntermAggregate *functionCall)
{
    ASSERT(functionCall->getOp() == EOpCallBuiltInFunction);

    const TFunction *func = functionCall->getFunction();

    if (BuiltInGroup::isImage(func))
    {
        TIntermSequence *arguments = functionCall->getSequence();
        TIntermTyped *imageNode    = (*arguments)[0]->getAsTyped();

        const TMemoryQualifier &memoryQualifier = imageNode->getMemoryQualifier();

        if (BuiltInGroup::isImageStore(func))
        {
            if (memoryQualifier.readonly)
            {
                error(imageNode->getLine(),
                      "'imageStore' cannot be used with images qualified as 'readonly'",
                      GetImageArgumentToken(imageNode));
            }
        }
        else if (BuiltInGroup::isImageLoad(func))
        {
            if (memoryQualifier.writeonly)
            {
                error(imageNode->getLine(),
                      "'imageLoad' cannot be used with images qualified as 'writeonly'",
                      GetImageArgumentToken(imageNode));
            }
        }
        else if (BuiltInGroup::isImageAtomic(func))
        {
            if (memoryQualifier.readonly)
            {
                error(imageNode->getLine(),
                      "'imageAtomic' cannot be used with images qualified as 'readonly'",
                      GetImageArgumentToken(imageNode));
            }
            if (memoryQualifier.writeonly)
            {
                error(imageNode->getLine(),
                      "'imageAtomic' cannot be used with images qualified as 'writeonly'",
                      GetImageArgumentToken(imageNode));
            }
        }
    }
}

// GLSL ES 3.10 Revision 4, 13.51 Matching of Memory Qualifiers in Function Parameters
void TParseContext::checkImageMemoryAccessForUserDefinedFunctions(
    const TFunction *functionDefinition,
    const TIntermAggregate *functionCall)
{
    ASSERT(functionCall->getOp() == EOpCallFunctionInAST);

    const TIntermSequence &arguments = *functionCall->getSequence();

    ASSERT(functionDefinition->getParamCount() == arguments.size());

    for (size_t i = 0; i < arguments.size(); ++i)
    {
        TIntermTyped *typedArgument        = arguments[i]->getAsTyped();
        const TType &functionArgumentType  = typedArgument->getType();
        const TType &functionParameterType = functionDefinition->getParam(i)->getType();
        ASSERT(functionArgumentType.getBasicType() == functionParameterType.getBasicType());

        if (IsImage(functionArgumentType.getBasicType()))
        {
            const TMemoryQualifier &functionArgumentMemoryQualifier =
                functionArgumentType.getMemoryQualifier();
            const TMemoryQualifier &functionParameterMemoryQualifier =
                functionParameterType.getMemoryQualifier();
            if (functionArgumentMemoryQualifier.readonly &&
                !functionParameterMemoryQualifier.readonly)
            {
                error(functionCall->getLine(),
                      "Function call discards the 'readonly' qualifier from image",
                      GetImageArgumentToken(typedArgument));
            }

            if (functionArgumentMemoryQualifier.writeonly &&
                !functionParameterMemoryQualifier.writeonly)
            {
                error(functionCall->getLine(),
                      "Function call discards the 'writeonly' qualifier from image",
                      GetImageArgumentToken(typedArgument));
            }

            if (functionArgumentMemoryQualifier.coherent &&
                !functionParameterMemoryQualifier.coherent)
            {
                error(functionCall->getLine(),
                      "Function call discards the 'coherent' qualifier from image",
                      GetImageArgumentToken(typedArgument));
            }

            if (functionArgumentMemoryQualifier.volatileQualifier &&
                !functionParameterMemoryQualifier.volatileQualifier)
            {
                error(functionCall->getLine(),
                      "Function call discards the 'volatile' qualifier from image",
                      GetImageArgumentToken(typedArgument));
            }
        }
    }
}

TIntermTyped *TParseContext::addFunctionCallOrMethod(TFunctionLookup *fnCall, const TSourceLoc &loc)
{
    if (fnCall->thisNode() != nullptr)
    {
        return addMethod(fnCall, loc);
    }
    if (fnCall->isConstructor())
    {
        return addConstructor(fnCall, loc);
    }
    return addNonConstructorFunctionCall(fnCall, loc);
}

TIntermTyped *TParseContext::addMethod(TFunctionLookup *fnCall, const TSourceLoc &loc)
{
    TIntermTyped *thisNode = fnCall->thisNode();
    // It's possible for the name pointer in the TFunction to be null in case it gets parsed as
    // a constructor. But such a TFunction can't reach here, since the lexer goes into FIELDS
    // mode after a dot, which makes type identifiers to be parsed as FIELD_SELECTION instead.
    // So accessing fnCall->name() below is safe.
    if (fnCall->name() != "length")
    {
        error(loc, "invalid method", fnCall->name());
    }
    else if (!fnCall->arguments().empty())
    {
        error(loc, "method takes no parameters", "length");
    }
    else if (!thisNode->isArray())
    {
        error(loc, "length can only be called on arrays", "length");
    }
    else if (thisNode->getQualifier() == EvqPerVertexIn &&
             mGeometryShaderInputPrimitiveType == EptUndefined)
    {
        ASSERT(mShaderType == GL_GEOMETRY_SHADER_EXT);
        error(loc, "missing input primitive declaration before calling length on gl_in", "length");
    }
    else
    {
        TIntermUnary *node = new TIntermUnary(EOpArrayLength, thisNode, nullptr);
        markStaticReadIfSymbol(thisNode);
        node->setLine(loc);
        return node->fold(mDiagnostics);
    }
    return CreateZeroNode(TType(EbtInt, EbpUndefined, EvqConst));
}

TIntermTyped *TParseContext::addNonConstructorFunctionCall(TFunctionLookup *fnCall,
                                                           const TSourceLoc &loc)
{
    // First check whether the function has been hidden by a variable name or struct typename by
    // using the symbol looked up in the lexical phase. If the function is not hidden, look for one
    // with a matching argument list.
    if (fnCall->symbol() != nullptr && !fnCall->symbol()->isFunction())
    {
        error(loc, "function name expected", fnCall->name());
    }
    else
    {
        // There are no inner functions, so it's enough to look for user-defined functions in the
        // global scope.
        const TSymbol *symbol = symbolTable.findGlobal(fnCall->getMangledName());

        if (symbol == nullptr && IsDesktopGLSpec(mShaderSpec))
        {
            // If using Desktop GL spec, need to check for implicit conversion
            symbol = symbolTable.findGlobalWithConversion(
                fnCall->getMangledNamesForImplicitConversions());
        }

        if (symbol != nullptr)
        {
            // A user-defined function - could be an overloaded built-in as well.
            ASSERT(symbol->symbolType() == SymbolType::UserDefined);
            const TFunction *fnCandidate = static_cast<const TFunction *>(symbol);
            TIntermAggregate *callNode =
                TIntermAggregate::CreateFunctionCall(*fnCandidate, &fnCall->arguments());
            callNode->setLine(loc);
            checkImageMemoryAccessForUserDefinedFunctions(fnCandidate, callNode);
            functionCallRValueLValueErrorCheck(fnCandidate, callNode);
            return callNode;
        }

        symbol = symbolTable.findBuiltIn(fnCall->getMangledName(), mShaderVersion);

        if (symbol == nullptr && IsDesktopGLSpec(mShaderSpec))
        {
            // If using Desktop GL spec, need to check for implicit conversion
            symbol = symbolTable.findBuiltInWithConversion(
                fnCall->getMangledNamesForImplicitConversions(), mShaderVersion);
        }

        if (symbol != nullptr)
        {
            // A built-in function.
            ASSERT(symbol->symbolType() == SymbolType::BuiltIn);
            const TFunction *fnCandidate = static_cast<const TFunction *>(symbol);

            if (fnCandidate->extension() != TExtension::UNDEFINED)
            {
                checkCanUseExtension(loc, fnCandidate->extension());
            }
            TOperator op = fnCandidate->getBuiltInOp();
            if (op != EOpCallBuiltInFunction)
            {
                // A function call mapped to a built-in operation.
                if (fnCandidate->getParamCount() == 1)
                {
                    // Treat it like a built-in unary operator.
                    TIntermNode *unaryParamNode = fnCall->arguments().front();
                    TIntermTyped *callNode =
                        createUnaryMath(op, unaryParamNode->getAsTyped(), loc, fnCandidate);
                    ASSERT(callNode != nullptr);
                    return callNode;
                }

                TIntermAggregate *callNode =
                    TIntermAggregate::CreateBuiltInFunctionCall(*fnCandidate, &fnCall->arguments());
                callNode->setLine(loc);

                checkAtomicMemoryBuiltinFunctions(callNode);

                // Some built-in functions have out parameters too.
                functionCallRValueLValueErrorCheck(fnCandidate, callNode);

                // See if we can constant fold a built-in. Note that this may be possible
                // even if it is not const-qualified.
                return callNode->fold(mDiagnostics);
            }

            // This is a built-in function with no op associated with it.
            TIntermAggregate *callNode =
                TIntermAggregate::CreateBuiltInFunctionCall(*fnCandidate, &fnCall->arguments());
            callNode->setLine(loc);
            checkTextureOffset(callNode);
            checkTextureGather(callNode);
            checkInterpolationFS(callNode);
            checkImageMemoryAccessForBuiltinFunctions(callNode);
            functionCallRValueLValueErrorCheck(fnCandidate, callNode);
            return callNode;
        }
        else
        {
            error(loc, "no matching overloaded function found", fnCall->name());
        }
    }

    // Error message was already written. Put on an unused node for error recovery.
    return CreateZeroNode(TType(EbtFloat, EbpMedium, EvqConst));
}

TIntermTyped *TParseContext::addTernarySelection(TIntermTyped *cond,
                                                 TIntermTyped *trueExpression,
                                                 TIntermTyped *falseExpression,
                                                 const TSourceLoc &loc)
{
    if (!checkIsScalarBool(loc, cond))
    {
        return falseExpression;
    }

    if (trueExpression->getType() != falseExpression->getType())
    {
        TInfoSinkBase reasonStream;
        reasonStream << "mismatching ternary operator operand types '" << trueExpression->getType()
                     << " and '" << falseExpression->getType() << "'";
        error(loc, reasonStream.c_str(), "?:");
        return falseExpression;
    }
    if (IsOpaqueType(trueExpression->getBasicType()))
    {
        // ESSL 1.00 section 4.1.7
        // ESSL 3.00.6 section 4.1.7
        // Opaque/sampler types are not allowed in most types of expressions, including ternary.
        // Note that structs containing opaque types don't need to be checked as structs are
        // forbidden below.
        error(loc, "ternary operator is not allowed for opaque types", "?:");
        return falseExpression;
    }

    if (cond->getMemoryQualifier().writeonly || trueExpression->getMemoryQualifier().writeonly ||
        falseExpression->getMemoryQualifier().writeonly)
    {
        error(loc, "ternary operator is not allowed for variables with writeonly", "?:");
        return falseExpression;
    }

    // ESSL 1.00.17 sections 5.2 and 5.7:
    // Ternary operator is not among the operators allowed for structures/arrays.
    // ESSL 3.00.6 section 5.7:
    // Ternary operator support is optional for arrays. No certainty that it works across all
    // devices with struct either, so we err on the side of caution here. TODO (oetuaho@nvidia.com):
    // Would be nice to make the spec and implementation agree completely here.
    if (trueExpression->isArray() || trueExpression->getBasicType() == EbtStruct)
    {
        error(loc, "ternary operator is not allowed for structures or arrays", "?:");
        return falseExpression;
    }
    if (trueExpression->getBasicType() == EbtInterfaceBlock)
    {
        error(loc, "ternary operator is not allowed for interface blocks", "?:");
        return falseExpression;
    }

    // WebGL2 section 5.26, the following results in an error:
    // "Ternary operator applied to void, arrays, or structs containing arrays"
    if (mShaderSpec == SH_WEBGL2_SPEC && trueExpression->getBasicType() == EbtVoid)
    {
        error(loc, "ternary operator is not allowed for void", "?:");
        return falseExpression;
    }

    TIntermTernary *node = new TIntermTernary(cond, trueExpression, falseExpression);
    markStaticReadIfSymbol(cond);
    markStaticReadIfSymbol(trueExpression);
    markStaticReadIfSymbol(falseExpression);
    node->setLine(loc);
    return expressionOrFoldedResult(node);
}

//
// Parse an array of strings using yyparse.
//
// Returns 0 for success.
//
int PaParseStrings(size_t count,
                   const char *const string[],
                   const int length[],
                   TParseContext *context)
{
    if ((count == 0) || (string == nullptr))
        return 1;

    if (glslang_initialize(context))
        return 1;

    int error = glslang_scan(count, string, length, context);
    if (!error)
        error = glslang_parse(context);

    glslang_finalize(context);

    return (error == 0) && (context->numErrors() == 0) ? 0 : 1;
}

}  // namespace sh
kc3-lang/angle/src/compiler/translator/ParseContext.cpp

Commit

kc3-lang/angle /src/compiler/translator/ParseContext.cpp
