ParseContext.cpp

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Author : Olli Etuaho
Date : 2016-12-16 12:01:18
Hash : 77ba408a
Message : Unify Diagnostics interface Use the same kind of interface for reporting preprocessor errors as for reporting regular compiler errors, and make global errors like having too many uniforms also go through Diagnostics. Also don't create std::string objects unnecessarily. Includes cleanups of some dead code related to reporting errors. BUG=angleproject:1670 TEST=angle_unittests Change-Id: I3ee794d32ddeec1826bdf1b76b558f35259f82c0 Reviewed-on: https://chromium-review.googlesource.com/421527 Reviewed-by: Corentin Wallez <cwallez@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org> Commit-Queue: Olli Etuaho <oetuaho@nvidia.com>
src/compiler/translator/ParseContext.cpp
//
// Copyright (c) 2002-2014 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 "compiler/preprocessor/SourceLocation.h"
#include "compiler/translator/Cache.h"
#include "compiler/translator/glslang.h"
#include "compiler/translator/ValidateSwitch.h"
#include "compiler/translator/ValidateGlobalInitializer.h"
#include "compiler/translator/util.h"

namespace sh
{

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

namespace
{

const int kWebGLMaxStructNesting = 4;

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

    if (type.getBasicType() == EbtStruct || type.isInterfaceBlock())
    {
        const TFieldList &fields = type.getStruct()->fields();
        for (unsigned int i = 0; i < fields.size(); ++i)
        {
            if (ContainsSampler(*fields[i]->type()))
                return true;
        }
    }

    return false;
}

bool ContainsImage(const TType &type)
{
    if (IsImage(type.getBasicType()))
        return true;

    if (type.getBasicType() == EbtStruct || type.isInterfaceBlock())
    {
        const TFieldList &fields = type.getStruct()->fields();
        for (unsigned int i = 0; i < fields.size(); ++i)
        {
            if (ContainsImage(*fields[i]->type()))
                return true;
        }
    }

    return false;
}

}  // namespace

TParseContext::TParseContext(TSymbolTable &symt,
                             TExtensionBehavior &ext,
                             sh::GLenum type,
                             ShShaderSpec spec,
                             ShCompileOptions options,
                             bool checksPrecErrors,
                             TDiagnostics *diagnostics,
                             const ShBuiltInResources &resources)
    : intermediate(),
      symbolTable(symt),
      mDeferredSingleDeclarationErrorCheck(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),
      mDefaultMatrixPacking(EmpColumnMajor),
      mDefaultBlockStorage(sh::IsWebGLBasedSpec(spec) ? EbsStd140 : EbsShared),
      mDiagnostics(diagnostics),
      mDirectiveHandler(ext,
                        *mDiagnostics,
                        mShaderVersion,
                        mShaderType,
                        resources.WEBGL_debug_shader_precision == 1),
      mPreprocessor(mDiagnostics, &mDirectiveHandler, pp::PreprocessorSettings()),
      mScanner(nullptr),
      mUsesFragData(false),
      mUsesFragColor(false),
      mUsesSecondaryOutputs(false),
      mMinProgramTexelOffset(resources.MinProgramTexelOffset),
      mMaxProgramTexelOffset(resources.MaxProgramTexelOffset),
      mComputeShaderLocalSizeDeclared(false),
      mDeclaringFunction(false)
{
    mComputeShaderLocalSize.fill(-1);
}

//
// Look at a '.' field selector string and change it into offsets
// for a vector.
//
bool TParseContext::parseVectorFields(const TString &compString,
                                      int vecSize,
                                      TVectorFields &fields,
                                      const TSourceLoc &line)
{
    fields.num = (int)compString.size();
    if (fields.num > 4)
    {
        error(line, "illegal vector field selection", compString.c_str());
        return false;
    }

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

    for (int i = 0; i < fields.num; ++i)
    {
        switch (compString[i])
        {
            case 'x':
                fields.offsets[i] = 0;
                fieldSet[i]       = exyzw;
                break;
            case 'r':
                fields.offsets[i] = 0;
                fieldSet[i]       = ergba;
                break;
            case 's':
                fields.offsets[i] = 0;
                fieldSet[i]       = estpq;
                break;
            case 'y':
                fields.offsets[i] = 1;
                fieldSet[i]       = exyzw;
                break;
            case 'g':
                fields.offsets[i] = 1;
                fieldSet[i]       = ergba;
                break;
            case 't':
                fields.offsets[i] = 1;
                fieldSet[i]       = estpq;
                break;
            case 'z':
                fields.offsets[i] = 2;
                fieldSet[i]       = exyzw;
                break;
            case 'b':
                fields.offsets[i] = 2;
                fieldSet[i]       = ergba;
                break;
            case 'p':
                fields.offsets[i] = 2;
                fieldSet[i]       = estpq;
                break;

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

    for (int i = 0; i < fields.num; ++i)
    {
        if (fields.offsets[i] >= vecSize)
        {
            error(line, "vector field selection out of range", compString.c_str());
            return false;
        }

        if (i > 0)
        {
            if (fieldSet[i] != fieldSet[i - 1])
            {
                error(line, "illegal - vector component fields not from the same set",
                      compString.c_str());
                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::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, TString left, TString right)
{
    std::stringstream reasonStream;
    reasonStream << "cannot convert from '" << right << "' to '" << left << "'";
    std::string reason = reasonStream.str();
    error(line, reason.c_str(), op);
}

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

//
// Same error message for all binary operations don't work.
//
void TParseContext::binaryOpError(const TSourceLoc &line,
                                  const char *op,
                                  TString left,
                                  TString right)
{
    std::stringstream 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)";
    std::string reason = reasonStream.str();
    error(line, reason.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 (IsSampler(type))
                {
                    error(line, "No precision specified (sampler)", "");
                    return;
                }
                if (IsImage(type))
                {
                    error(line, "No precision specified (image)", "");
                    return;
                }
        }
    }
}

// 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)
{
    TIntermSymbol *symNode      = node->getAsSymbolNode();
    TIntermBinary *binaryNode   = node->getAsBinaryNode();
    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;
    }

    if (binaryNode)
    {
        switch (binaryNode->getOp())
        {
            case EOpIndexDirect:
            case EOpIndexIndirect:
            case EOpIndexDirectStruct:
            case EOpIndexDirectInterfaceBlock:
                return checkCanBeLValue(line, op, binaryNode->getLeft());
            default:
                break;
        }
        error(line, " l-value required", op);
        return false;
    }

    const char *message = 0;
    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:
            message = "can't modify an input";
            break;
        case EvqVertexIn:
            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 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 EvqComputeIn:
            message = "can't modify work group size variable";
            break;
        default:
            //
            // Type that can't be written to?
            //
            if (node->getBasicType() == EbtVoid)
            {
                message = "can't modify void";
            }
            if (IsSampler(node->getBasicType()))
            {
                message = "can't modify a sampler";
            }
            if (IsImage(node->getBasicType()))
            {
                message = "can't modify an image";
            }
    }

    if (message == 0 && binaryNode == 0 && symNode == 0)
    {
        error(line, "l-value required", op);

        return false;
    }

    //
    // Everything else is okay, no error.
    //
    if (message == 0)
        return true;

    //
    // If we get here, we have an error and a message.
    //
    if (symNode)
    {
        const char *symbol = symNode->getSymbol().c_str();
        std::stringstream reasonStream;
        reasonStream << "l-value required (" << message << " \"" << symbol << "\")";
        std::string reason = reasonStream.str();
        error(line, reason.c_str(), op);
    }
    else
    {
        std::stringstream reasonStream;
        reasonStream << "l-value required (" << 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;
}

// For now, keep it simple:  if it starts "gl_", it's reserved, independent
// of scope.  Except, if the symbol table is at the built-in push-level,
// which is when we are parsing built-ins.
// Also checks for "webgl_" and "_webgl_" reserved identifiers if parsing a
// webgl shader.
bool TParseContext::checkIsNotReserved(const TSourceLoc &line, const TString &identifier)
{
    static const char *reservedErrMsg = "reserved built-in name";
    if (!symbolTable.atBuiltInLevel())
    {
        if (identifier.compare(0, 3, "gl_") == 0)
        {
            error(line, reservedErrMsg, "gl_");
            return false;
        }
        if (sh::IsWebGLBasedSpec(mShaderSpec))
        {
            if (identifier.compare(0, 6, "webgl_") == 0)
            {
                error(line, reservedErrMsg, "webgl_");
                return false;
            }
            if (identifier.compare(0, 7, "_webgl_") == 0)
            {
                error(line, reservedErrMsg, "_webgl_");
                return false;
            }
        }
        if (identifier.find("__") != TString::npos)
        {
            error(line,
                  "identifiers containing two consecutive underscores (__) are reserved as "
                  "possible future keywords",
                  identifier.c_str());
            return false;
        }
    }

    return true;
}

// Make sure there is enough data provided to the constructor to build
// something of the type of the constructor.  Also returns the type of
// the constructor.
bool TParseContext::checkConstructorArguments(const TSourceLoc &line,
                                              TIntermNode *argumentsNode,
                                              const TFunction &function,
                                              TOperator op,
                                              const TType &type)
{
    bool constructingMatrix = false;
    switch (op)
    {
        case EOpConstructMat2:
        case EOpConstructMat2x3:
        case EOpConstructMat2x4:
        case EOpConstructMat3x2:
        case EOpConstructMat3:
        case EOpConstructMat3x4:
        case EOpConstructMat4x2:
        case EOpConstructMat4x3:
        case EOpConstructMat4:
            constructingMatrix = true;
            break;
        default:
            break;
    }

    //
    // 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 matrixInMatrix = false;
    bool arrayArg       = false;
    for (size_t i = 0; i < function.getParamCount(); ++i)
    {
        const TConstParameter &param = function.getParam(i);
        size += param.type->getObjectSize();

        if (constructingMatrix && param.type->isMatrix())
            matrixInMatrix = true;
        if (full)
            overFull = true;
        if (op != EOpConstructStruct && !type.isArray() && size >= type.getObjectSize())
            full = true;
        if (param.type->isArray())
            arrayArg = true;
    }

    if (type.isArray())
    {
        // The size of an unsized constructor should already have been determined.
        ASSERT(!type.isUnsizedArray());
        if (static_cast<size_t>(type.getArraySize()) != function.getParamCount())
        {
            error(line, "array constructor needs one argument per array element", "constructor");
            return false;
        }
    }

    if (arrayArg && op != EOpConstructStruct)
    {
        error(line, "constructing from a non-dereferenced array", "constructor");
        return false;
    }

    if (matrixInMatrix && !type.isArray())
    {
        if (function.getParamCount() != 1)
        {
            error(line, "constructing matrix from matrix can only take one argument",
                  "constructor");
            return false;
        }
    }

    if (overFull)
    {
        error(line, "too many arguments", "constructor");
        return false;
    }

    if (op == EOpConstructStruct && !type.isArray() &&
        type.getStruct()->fields().size() != function.getParamCount())
    {
        error(line,
              "Number of constructor parameters does not match the number of structure fields",
              "constructor");
        return false;
    }

    if (!type.isMatrix() || !matrixInMatrix)
    {
        if ((op != EOpConstructStruct && size != 1 && size < type.getObjectSize()) ||
            (op == EOpConstructStruct && size < type.getObjectSize()))
        {
            error(line, "not enough data provided for construction", "constructor");
            return false;
        }
    }

    if (argumentsNode == nullptr)
    {
        error(line, "constructor does not have any arguments", "constructor");
        return false;
    }

    TIntermAggregate *argumentsAgg = argumentsNode->getAsAggregate();
    for (TIntermNode *&argNode : *argumentsAgg->getSequence())
    {
        TIntermTyped *argTyped = argNode->getAsTyped();
        ASSERT(argTyped != nullptr);
        if (op != EOpConstructStruct && IsSampler(argTyped->getBasicType()))
        {
            error(line, "cannot convert a sampler", "constructor");
            return false;
        }
        if (op != EOpConstructStruct && IsImage(argTyped->getBasicType()))
        {
            error(line, "cannot convert an image", "constructor");
            return false;
        }
        if (argTyped->getBasicType() == EbtVoid)
        {
            error(line, "cannot convert a void", "constructor");
            return false;
        }
    }

    if (type.isArray())
    {
        // GLSL ES 3.00 section 5.4.4: Each argument must be the same type as the element type of
        // the array.
        for (TIntermNode *&argNode : *argumentsAgg->getSequence())
        {
            const TType &argType = argNode->getAsTyped()->getType();
            // It has already been checked that the argument is not an array.
            ASSERT(!argType.isArray());
            if (!argType.sameElementType(type))
            {
                error(line, "Array constructor argument has an incorrect type", "constructor");
                return false;
            }
        }
    }
    else if (op == EOpConstructStruct)
    {
        const TFieldList &fields = type.getStruct()->fields();
        TIntermSequence *args    = argumentsAgg->getSequence();

        for (size_t i = 0; i < fields.size(); i++)
        {
            if (i >= args->size() || (*args)[i]->getAsTyped()->getType() != *fields[i]->type())
            {
                error(line, "Structure constructor arguments do not match structure fields",
                      "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 TString &identifier,
                                   const TBasicType &type)
{
    if (type == EbtVoid)
    {
        error(line, "illegal use of type 'void'", identifier.c_str());
        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 TIntermTyped *type)
{
    if (type->getBasicType() != EbtBool || type->isArray() || type->isMatrix() || type->isVector())
    {
        error(line, "boolean expression expected", "");
    }
}

// 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::checkIsNotSampler(const TSourceLoc &line,
                                      const TTypeSpecifierNonArray &pType,
                                      const char *reason)
{
    if (pType.type == EbtStruct)
    {
        if (ContainsSampler(*pType.userDef))
        {
            std::stringstream reasonStream;
            reasonStream << reason << " (structure contains a sampler)";
            std::string reasonStr = reasonStream.str();
            error(line, reasonStr.c_str(), getBasicString(pType.type));
            return false;
        }

        return true;
    }
    else if (IsSampler(pType.type))
    {
        error(line, reason, getBasicString(pType.type));
        return false;
    }

    return true;
}

bool TParseContext::checkIsNotImage(const TSourceLoc &line,
                                    const TTypeSpecifierNonArray &pType,
                                    const char *reason)
{
    if (pType.type == EbtStruct)
    {
        if (ContainsImage(*pType.userDef))
        {
            std::stringstream reasonStream;
            reasonStream << reason << " (structure contains an image)";
            std::string reasonStr = reasonStream.str();
            error(line, reasonStr.c_str(), getBasicString(pType.type));

            return false;
        }

        return true;
    }
    else if (IsImage(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)
    {
        error(location, "invalid layout qualifier: only valid on program inputs and outputs",
              "location");
    }
}

void TParseContext::checkOutParameterIsNotOpaqueType(const TSourceLoc &line,
                                                     TQualifier qualifier,
                                                     const TType &type)
{
    checkOutParameterIsNotSampler(line, qualifier, type);
    checkOutParameterIsNotImage(line, qualifier, type);
}

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

void TParseContext::checkOutParameterIsNotImage(const TSourceLoc &line,
                                                TQualifier qualifier,
                                                const TType &type)
{
    ASSERT(qualifier == EvqOut || qualifier == EvqInOut);
    if (IsImage(type.getBasicType()))
    {
        error(line, "images 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();

    // TODO(oetuaho@nvidia.com): Get rid of the constant == nullptr check here once all constant
    // expressions can be folded. Right now we don't allow constant expressions that ANGLE can't
    // fold as array size.
    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;
    }

    // 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::checkIsValidTypeForArray(const TSourceLoc &line, const TPublicType &elementType)
{
    //
    // Can the type be an array?
    //
    if (elementType.array)
    {
        error(line, "cannot declare arrays of arrays",
              TType(elementType).getCompleteString().c_str());
        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).
    if (mShaderVersion >= 300 && elementType.getBasicType() == EbtStruct &&
        sh::IsVarying(elementType.qualifier))
    {
        error(line, "cannot declare arrays of structs of this qualifier",
              TType(elementType).getCompleteString().c_str());
        return false;
    }

    return true;
}

// Check if this qualified element type can be formed into an array.
bool TParseContext::checkIsValidTypeAndQualifierForArray(const TSourceLoc &indexLocation,
                                                         const TPublicType &elementType)
{
    if (checkIsValidTypeForArray(indexLocation, elementType))
    {
        return checkIsValidQualifierForArray(indexLocation, elementType);
    }
    return false;
}

// Enforce non-initializer type/qualifier rules.
void TParseContext::checkCanBeDeclaredWithoutInitializer(const TSourceLoc &line,
                                                         const TString &identifier,
                                                         TPublicType *type)
{
    ASSERT(type != nullptr);
    if (type->qualifier == EvqConst)
    {
        // Make the qualifier make sense.
        type->qualifier = 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.c_str());
        }
        else
        {
            error(line, "variables with qualifier 'const' must be initialized", identifier.c_str());
        }
        return;
    }
    if (type->isUnsizedArray())
    {
        error(line, "implicitly sized arrays need to be initialized", identifier.c_str());
    }
}

// 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 TString &identifier,
                                    const TType &type,
                                    TVariable **variable)
{
    ASSERT((*variable) == nullptr);

    bool needsReservedCheck = true;

    // gl_LastFragData may be redeclared with a new precision qualifier
    if (type.isArray() && identifier.compare(0, 15, "gl_LastFragData") == 0)
    {
        const TVariable *maxDrawBuffers = static_cast<const TVariable *>(
            symbolTable.findBuiltIn("gl_MaxDrawBuffers", mShaderVersion));
        if (static_cast<int>(type.getArraySize()) == maxDrawBuffers->getConstPointer()->getIConst())
        {
            if (TSymbol *builtInSymbol = symbolTable.findBuiltIn(identifier, mShaderVersion))
            {
                needsReservedCheck = !checkCanUseExtension(line, builtInSymbol->getExtension());
            }
        }
        else
        {
            error(line, "redeclaration of gl_LastFragData with size != gl_MaxDrawBuffers",
                  identifier.c_str());
            return false;
        }
    }

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

    (*variable) = new TVariable(&identifier, type);
    if (!symbolTable.declare(*variable))
    {
        error(line, "redefinition", identifier.c_str());
        *variable = nullptr;
        return false;
    }

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

    return true;
}

void TParseContext::checkIsParameterQualifierValid(
    const TSourceLoc &line,
    const TTypeQualifierBuilder &typeQualifierBuilder,
    TType *type)
{
    TTypeQualifier typeQualifier = typeQualifierBuilder.getParameterTypeQualifier(mDiagnostics);

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

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

    type->setQualifier(typeQualifier.qualifier);

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

bool TParseContext::checkCanUseExtension(const TSourceLoc &line, const TString &extension)
{
    const TExtensionBehavior &extBehavior   = extensionBehavior();
    TExtensionBehavior::const_iterator iter = extBehavior.find(extension.c_str());
    if (iter == extBehavior.end())
    {
        error(line, "extension is not supported", extension.c_str());
        return false;
    }
    // In GLSL ES, an extension's default behavior is "disable".
    if (iter->second == EBhDisable || iter->second == EBhUndefined)
    {
        error(line, "extension is disabled", extension.c_str());
        return false;
    }
    if (iter->second == EBhWarn)
    {
        warning(line, "extension is being used", extension.c_str());
        return true;
    }

    return true;
}

void TParseContext::emptyDeclarationErrorCheck(const TPublicType &publicType,
                                               const TSourceLoc &location)
{
    if (publicType.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 (publicType.qualifier == EvqShared && !publicType.layoutQualifier.isEmpty())
    {
        error(location, "Shared memory declarations cannot have layout specified", "layout");
    }
}

// These checks are common for all declarations starting a declarator list, and declarators that
// follow an empty declaration.
void TParseContext::singleDeclarationErrorCheck(const TPublicType &publicType,
                                                const TSourceLoc &identifierLocation)
{
    switch (publicType.qualifier)
    {
        case EvqVaryingIn:
        case EvqVaryingOut:
        case EvqAttribute:
        case EvqVertexIn:
        case EvqFragmentOut:
        case EvqComputeIn:
            if (publicType.getBasicType() == EbtStruct)
            {
                error(identifierLocation, "cannot be used with a structure",
                      getQualifierString(publicType.qualifier));
                return;
            }

        default:
            break;
    }

    if (publicType.qualifier != EvqUniform &&
        !checkIsNotSampler(identifierLocation, publicType.typeSpecifierNonArray,
                           "samplers must be uniform"))
    {
        return;
    }
    if (publicType.qualifier != EvqUniform &&
        !checkIsNotImage(identifierLocation, publicType.typeSpecifierNonArray,
                         "images must be uniform"))
    {
        return;
    }

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

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

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

    if (publicType.qualifier != EvqVertexIn && publicType.qualifier != EvqFragmentOut)
    {
        checkLocationIsNotSpecified(identifierLocation, 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
    {

        if (!checkInternalFormatIsNotSpecified(identifierLocation,
                                               layoutQualifier.imageInternalFormat))
        {
            return;
        }

        if (!checkIsMemoryQualifierNotSpecified(publicType.memoryQualifier, identifierLocation))
        {
            return;
        }
    }
}

void TParseContext::checkLayoutQualifierSupported(const TSourceLoc &location,
                                                  const TString &layoutQualifierName,
                                                  int versionRequired)
{

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

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;
}

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

void TParseContext::functionCallLValueErrorCheck(const TFunction *fnCandidate,
                                                 TIntermAggregate *fnCall)
{
    for (size_t i = 0; i < fnCandidate->getParamCount(); ++i)
    {
        TQualifier qual = fnCandidate->getParam(i).type->getQualifier();
        if (qual == EvqOut || qual == EvqInOut)
        {
            TIntermTyped *argument = (*(fnCall->getSequence()))[i]->getAsTyped();
            if (!checkCanBeLValue(argument->getLine(), "assign", argument))
            {
                TString unmangledName =
                    TFunction::unmangleName(fnCall->getFunctionSymbolInfo()->getName());
                error(argument->getLine(),
                      "Constant value cannot be passed for 'out' or 'inout' parameters.",
                      unmangledName.c_str());
                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::supportsExtension(const char *extension)
{
    const TExtensionBehavior &extbehavior   = extensionBehavior();
    TExtensionBehavior::const_iterator iter = extbehavior.find(extension);
    return (iter != extbehavior.end());
}

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

void TParseContext::handleExtensionDirective(const TSourceLoc &loc,
                                             const char *extName,
                                             const char *behavior)
{
    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)
{
    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;
    for (size_t i = 0u; i < result.size(); ++i)
    {
        if (mComputeShaderLocalSizeDeclared && mComputeShaderLocalSize[i] == -1)
        {
            result[i] = 1;
        }
        else
        {
            result[i] = mComputeShaderLocalSize[i];
        }
    }
    return result;
}

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

const TVariable *TParseContext::getNamedVariable(const TSourceLoc &location,
                                                 const TString *name,
                                                 const TSymbol *symbol)
{
    const TVariable *variable = NULL;

    if (!symbol)
    {
        error(location, "undeclared identifier", name->c_str());
    }
    else if (!symbol->isVariable())
    {
        error(location, "variable expected", name->c_str());
    }
    else
    {
        variable = static_cast<const TVariable *>(symbol);

        if (symbolTable.findBuiltIn(variable->getName(), mShaderVersion) &&
            !variable->getExtension().empty())
        {
            checkCanUseExtension(location, variable->getExtension());
        }

        // Reject shaders using both gl_FragData and gl_FragColor
        TQualifier qualifier = variable->getType().getQualifier();
        if (qualifier == EvqFragData || qualifier == EvqSecondaryFragDataEXT)
        {
            mUsesFragData = true;
        }
        else if (qualifier == EvqFragColor || qualifier == EvqSecondaryFragColorEXT)
        {
            mUsesFragColor = true;
        }
        if (qualifier == EvqSecondaryFragDataEXT || qualifier == EvqSecondaryFragColorEXT)
        {
            mUsesSecondaryOutputs = true;
        }

        // This validation is not quite correct - it's only an error to write to
        // both FragData and FragColor. For simplicity, and because users shouldn't
        // be rewarded for reading from undefined varaibles, return an error
        // if they are both referenced, rather than assigned.
        if (mUsesFragData && mUsesFragColor)
        {
            const char *errorMessage = "cannot use both gl_FragData and gl_FragColor";
            if (mUsesSecondaryOutputs)
            {
                errorMessage =
                    "cannot use both output variable sets (gl_FragData, gl_SecondaryFragDataEXT)"
                    " and (gl_FragColor, gl_SecondaryFragColorEXT)";
            }
            error(location, errorMessage, name->c_str());
        }

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

    if (!variable)
    {
        TType type(EbtFloat, EbpUndefined);
        TVariable *fakeVariable = new TVariable(name, type);
        symbolTable.declare(fakeVariable);
        variable = fakeVariable;
    }

    return variable;
}

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

    if (variable->getConstPointer())
    {
        const TConstantUnion *constArray = variable->getConstPointer();
        return intermediate.addConstantUnion(constArray, variable->getType(), location);
    }
    else if (variable->getType().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(variable->getType().getBasicType() == EbtUInt);
        ASSERT(variable->getType().getObjectSize() == 3);

        TType type(variable->getType());
        type.setQualifier(EvqConst);
        return intermediate.addConstantUnion(constArray, type, location);
    }
    else
    {
        return intermediate.addSymbol(variable->getUniqueId(), variable->getName(),
                                      variable->getType(), location);
    }
}

//
// Look up a function name in the symbol table, and make sure it is a function.
//
// Return the function symbol if found, otherwise 0.
//
const TFunction *TParseContext::findFunction(const TSourceLoc &line,
                                             TFunction *call,
                                             int inputShaderVersion,
                                             bool *builtIn)
{
    // First find by unmangled name to check whether the function name has been
    // hidden by a variable name or struct typename.
    // If a function is found, check for one with a matching argument list.
    const TSymbol *symbol = symbolTable.find(call->getName(), inputShaderVersion, builtIn);
    if (symbol == 0 || symbol->isFunction())
    {
        symbol = symbolTable.find(call->getMangledName(), inputShaderVersion, builtIn);
    }

    if (symbol == 0)
    {
        error(line, "no matching overloaded function found", call->getName().c_str());
        return 0;
    }

    if (!symbol->isFunction())
    {
        error(line, "function name expected", call->getName().c_str());
        return 0;
    }

    return static_cast<const TFunction *>(symbol);
}

//
// Initializers show up in several places in the grammar.  Have one set of
// code to handle them here.
//
// Returns true on error, false if no error
//
bool TParseContext::executeInitializer(const TSourceLoc &line,
                                       const TString &identifier,
                                       const TPublicType &pType,
                                       TIntermTyped *initializer,
                                       TIntermBinary **initNode)
{
    ASSERT(initNode != nullptr);
    ASSERT(*initNode == nullptr);
    TType type = TType(pType);

    TVariable *variable = nullptr;
    if (type.isUnsizedArray())
    {
        // We have not checked yet whether the initializer actually is an array or not.
        if (initializer->isArray())
        {
            type.setArraySize(initializer->getArraySize());
        }
        else
        {
            // 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.setArraySize(1u);
        }
    }
    if (!declareVariable(line, identifier, type, &variable))
    {
        return true;
    }

    bool globalInitWarning = false;
    if (symbolTable.atGlobalLevel() &&
        !ValidateGlobalInitializer(initializer, this, &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 true;
    }
    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
    //
    TQualifier qualifier = variable->getType().getQualifier();
    if ((qualifier != EvqTemporary) && (qualifier != EvqGlobal) && (qualifier != EvqConst))
    {
        error(line, " cannot initialize this type of qualifier ",
              variable->getType().getQualifierString());
        return true;
    }
    //
    // test for and propagate constant
    //

    if (qualifier == EvqConst)
    {
        if (qualifier != initializer->getType().getQualifier())
        {
            std::stringstream reasonStream;
            reasonStream << "assigning non-constant to '" << variable->getType().getCompleteString()
                         << "'";
            std::string reason = reasonStream.str();
            error(line, reason.c_str(), "=");
            variable->getType().setQualifier(EvqTemporary);
            return true;
        }
        if (type != initializer->getType())
        {
            error(line, " non-matching types for const initializer ",
                  variable->getType().getQualifierString());
            variable->getType().setQualifier(EvqTemporary);
            return true;
        }

        // Save the constant folded value to the variable if possible. For example array
        // initializers are not folded, since that way copying the array literal to multiple places
        // in the shader is avoided.
        // TODO(oetuaho@nvidia.com): Consider constant folding array initialization in cases where
        // it would be beneficial.
        if (initializer->getAsConstantUnion())
        {
            variable->shareConstPointer(initializer->getAsConstantUnion()->getUnionArrayPointer());
            *initNode = nullptr;
            return false;
        }
        else if (initializer->getAsSymbolNode())
        {
            const TSymbol *symbol =
                symbolTable.find(initializer->getAsSymbolNode()->getSymbol(), 0);
            const TVariable *tVar = static_cast<const TVariable *>(symbol);

            const TConstantUnion *constArray = tVar->getConstPointer();
            if (constArray)
            {
                variable->shareConstPointer(constArray);
                *initNode = nullptr;
                return false;
            }
        }
    }

    TIntermSymbol *intermSymbol = intermediate.addSymbol(
        variable->getUniqueId(), variable->getName(), variable->getType(), line);
    *initNode = createAssign(EOpInitialize, intermSymbol, initializer, line);
    if (*initNode == nullptr)
    {
        assignError(line, "=", intermSymbol->getCompleteString(), initializer->getCompleteString());
        return true;
    }

    return false;
}

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

    if (mShaderVersion < 300 && typeSpecifier->array)
    {
        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.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);

    if (mShaderVersion < 300)
    {
        if (typeSpecifier.array)
        {
            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)
        {
            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.array)
            {
                error(qualifierLocation, "cannot be array", getQualifierString(qualifier));
            }
            // Vertex inputs with a struct type are disallowed in singleDeclarationErrorCheck
            return;
        case EvqFragmentOut:
            // 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 singleDeclarationErrorCheck
            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));
    if (typeContainsIntegers && qualifier != EvqFlatIn && qualifier != EvqFlatOut)
    {
        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.array)
        {
            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().c_str());
        }
    }
}

bool TParseContext::checkIsMemoryQualifierNotSpecified(const TMemoryQualifier &memoryQualifier,
                                                       const TSourceLoc &location)
{
    if (memoryQualifier.readonly)
    {
        error(location, "Only allowed with images.", "readonly");
        return false;
    }
    if (memoryQualifier.writeonly)
    {
        error(location, "Only allowed with images.", "writeonly");
        return false;
    }
    if (memoryQualifier.coherent)
    {
        error(location, "Only allowed with images.", "coherent");
        return false;
    }
    if (memoryQualifier.restrictQualifier)
    {
        error(location, "Only allowed with images.", "restrict");
        return false;
    }
    if (memoryQualifier.volatileQualifier)
    {
        error(location, "Only allowed with images.", "volatile");
        return false;
    }
    return true;
}

TIntermDeclaration *TParseContext::parseSingleDeclaration(
    TPublicType &publicType,
    const TSourceLoc &identifierOrTypeLocation,
    const TString &identifier)
{
    TType type(publicType);
    if ((mCompileOptions & SH_FLATTEN_PRAGMA_STDGL_INVARIANT_ALL) &&
        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.
        //
        // 3. Inputs in ESSL 1.00 fragment shaders (EvqVaryingIn). This is somewhat in violation of
        // the specification, but there are desktop OpenGL drivers that expect that this is the
        // behavior of the #pragma when specified in ESSL 1.00 fragment shaders.
        if (qualifier == EvqVaryingOut || qualifier == EvqVertexOut || qualifier == EvqVaryingIn)
        {
            type.setInvariant(true);
        }
    }

    TIntermSymbol *symbol = intermediate.addSymbol(0, identifier, type, identifierOrTypeLocation);

    bool emptyDeclaration = (identifier == "");

    mDeferredSingleDeclarationErrorCheck = emptyDeclaration;

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

    if (emptyDeclaration)
    {
        emptyDeclarationErrorCheck(publicType, identifierOrTypeLocation);
    }
    else
    {
        singleDeclarationErrorCheck(publicType, identifierOrTypeLocation);

        checkCanBeDeclaredWithoutInitializer(identifierOrTypeLocation, identifier, &publicType);

        TVariable *variable = nullptr;
        declareVariable(identifierOrTypeLocation, identifier, type, &variable);

        if (variable && symbol)
        {
            symbol->setId(variable->getUniqueId());
        }
    }

    // We append the symbol even if the declaration is empty, mainly because of struct declarations
    // that may just declare a type.
    declaration->appendDeclarator(symbol);

    return declaration;
}

TIntermDeclaration *TParseContext::parseSingleArrayDeclaration(TPublicType &publicType,
                                                               const TSourceLoc &identifierLocation,
                                                               const TString &identifier,
                                                               const TSourceLoc &indexLocation,
                                                               TIntermTyped *indexExpression)
{
    mDeferredSingleDeclarationErrorCheck = false;

    singleDeclarationErrorCheck(publicType, identifierLocation);

    checkCanBeDeclaredWithoutInitializer(identifierLocation, identifier, &publicType);

    checkIsValidTypeAndQualifierForArray(indexLocation, publicType);

    TType arrayType(publicType);

    unsigned int size = checkIsValidArraySize(identifierLocation, indexExpression);
    // Make the type an array even if size check failed.
    // This ensures useless error messages regarding the variable's non-arrayness won't follow.
    arrayType.setArraySize(size);

    TVariable *variable = nullptr;
    declareVariable(identifierLocation, identifier, arrayType, &variable);

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

    TIntermSymbol *symbol = intermediate.addSymbol(0, identifier, arrayType, identifierLocation);
    if (variable && symbol)
    {
        symbol->setId(variable->getUniqueId());
        declaration->appendDeclarator(symbol);
    }

    return declaration;
}

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

    singleDeclarationErrorCheck(publicType, identifierLocation);

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

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

TIntermDeclaration *TParseContext::parseSingleArrayInitDeclaration(
    TPublicType &publicType,
    const TSourceLoc &identifierLocation,
    const TString &identifier,
    const TSourceLoc &indexLocation,
    TIntermTyped *indexExpression,
    const TSourceLoc &initLocation,
    TIntermTyped *initializer)
{
    mDeferredSingleDeclarationErrorCheck = false;

    singleDeclarationErrorCheck(publicType, identifierLocation);

    checkIsValidTypeAndQualifierForArray(indexLocation, publicType);

    TPublicType arrayType(publicType);

    unsigned int size = 0u;
    // If indexExpression is nullptr, then the array will eventually get its size implicitly from
    // the initializer.
    if (indexExpression != nullptr)
    {
        size = checkIsValidArraySize(identifierLocation, indexExpression);
    }
    // Make the type an array even if size check failed.
    // This ensures useless error messages regarding the variable's non-arrayness won't follow.
    arrayType.setArraySize(size);

    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;
}

TIntermInvariantDeclaration *TParseContext::parseInvariantDeclaration(
    const TTypeQualifierBuilder &typeQualifierBuilder,
    const TSourceLoc &identifierLoc,
    const TString *identifier,
    const TSymbol *symbol)
{
    TTypeQualifier typeQualifier = typeQualifierBuilder.getVariableTypeQualifier(mDiagnostics);

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

    const TVariable *variable = getNamedVariable(identifierLoc, identifier, symbol);
    ASSERT(variable);
    const TType &type = variable->getType();

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

    symbolTable.addInvariantVarying(std::string(identifier->c_str()));

    TIntermSymbol *intermSymbol =
        intermediate.addSymbol(variable->getUniqueId(), *identifier, type, identifierLoc);

    return new TIntermInvariantDeclaration(intermSymbol, identifierLoc);
}

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

    checkDeclaratorLocationIsNotSpecified(identifierLocation, publicType);

    checkCanBeDeclaredWithoutInitializer(identifierLocation, identifier, &publicType);

    TVariable *variable = nullptr;
    declareVariable(identifierLocation, identifier, TType(publicType), &variable);

    TIntermSymbol *symbol =
        intermediate.addSymbol(0, identifier, TType(publicType), identifierLocation);
    if (variable && symbol)
    {
        symbol->setId(variable->getUniqueId());
        declarationOut->appendDeclarator(symbol);
    }
}

void TParseContext::parseArrayDeclarator(TPublicType &publicType,
                                         const TSourceLoc &identifierLocation,
                                         const TString &identifier,
                                         const TSourceLoc &arrayLocation,
                                         TIntermTyped *indexExpression,
                                         TIntermDeclaration *declarationOut)
{
    // If the declaration starting this declarator list was empty (example: int,), some checks were
    // not performed.
    if (mDeferredSingleDeclarationErrorCheck)
    {
        singleDeclarationErrorCheck(publicType, identifierLocation);
        mDeferredSingleDeclarationErrorCheck = false;
    }

    checkDeclaratorLocationIsNotSpecified(identifierLocation, publicType);

    checkCanBeDeclaredWithoutInitializer(identifierLocation, identifier, &publicType);

    if (checkIsValidTypeAndQualifierForArray(arrayLocation, publicType))
    {
        TType arrayType   = TType(publicType);
        unsigned int size = checkIsValidArraySize(arrayLocation, indexExpression);
        arrayType.setArraySize(size);

        TVariable *variable = nullptr;
        declareVariable(identifierLocation, identifier, arrayType, &variable);

        TIntermSymbol *symbol =
            intermediate.addSymbol(0, identifier, arrayType, identifierLocation);
        if (variable && symbol)
            symbol->setId(variable->getUniqueId());

        declarationOut->appendDeclarator(symbol);
    }
}

void TParseContext::parseInitDeclarator(const TPublicType &publicType,
                                        const TSourceLoc &identifierLocation,
                                        const TString &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 (mDeferredSingleDeclarationErrorCheck)
    {
        singleDeclarationErrorCheck(publicType, identifierLocation);
        mDeferredSingleDeclarationErrorCheck = false;
    }

    checkDeclaratorLocationIsNotSpecified(identifierLocation, publicType);

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

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

    checkDeclaratorLocationIsNotSpecified(identifierLocation, publicType);

    checkIsValidTypeAndQualifierForArray(indexLocation, publicType);

    TPublicType arrayType(publicType);

    unsigned int size = 0u;
    // If indexExpression is nullptr, then the array will eventually get its size implicitly from
    // the initializer.
    if (indexExpression != nullptr)
    {
        size = checkIsValidArraySize(identifierLocation, indexExpression);
    }
    // Make the type an array even if size check failed.
    // This ensures useless error messages regarding the variable's non-arrayness won't follow.
    arrayType.setArraySize(size);

    // 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);
        }
    }
}

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 combination:", "layout");
        return;
    }

    checkIsMemoryQualifierNotSpecified(typeQualifier.memoryQualifier, typeQualifier.line);

    checkInternalFormatIsNotSpecified(typeQualifier.line, layoutQualifier.imageInternalFormat);

    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("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;
                    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 (!checkWorkGroupSizeIsNotSpecified(typeQualifier.line, typeQualifier.layoutQualifier))
        {
            return;
        }

        if (typeQualifier.qualifier != EvqUniform)
        {
            error(typeQualifier.line, "invalid qualifier: global layout must be uniform",
                  getQualifierString(typeQualifier.qualifier));
            return;
        }

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

        checkLocationIsNotSpecified(typeQualifier.line, typeQualifier.layoutQualifier);

        if (layoutQualifier.matrixPacking != EmpUnspecified)
        {
            mDefaultMatrixPacking = layoutQualifier.matrixPacking;
        }

        if (layoutQualifier.blockStorage != EbsUnspecified)
        {
            mDefaultBlockStorage = layoutQualifier.blockStorage;
        }
    }
}

TIntermAggregate *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.
    TFunction *function = static_cast<TFunction *>(
        symbolTable.find(parsedFunction.getMangledName(), getShaderVersion()));
    if (function->hasPrototypeDeclaration() && 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");
    }
    function->setHasPrototypeDeclaration();

    TIntermAggregate *prototype = new TIntermAggregate;
    // TODO(oetuaho@nvidia.com): Instead of converting the function information here, the node could
    // point to the data that already exists in the symbol table.
    prototype->setType(function->getReturnType());
    prototype->getFunctionSymbolInfo()->setFromFunction(*function);

    for (size_t i = 0; i < function->getParamCount(); i++)
    {
        const TConstParameter &param = function->getParam(i);
        if (param.name != 0)
        {
            TVariable variable(param.name, *param.type);

            TIntermSymbol *paramSymbol = intermediate.addSymbol(
                variable.getUniqueId(), variable.getName(), variable.getType(), location);
            prototype = intermediate.growAggregate(prototype, paramSymbol, location);
        }
        else
        {
            TIntermSymbol *paramSymbol = intermediate.addSymbol(0, "", *param.type, location);
            prototype = intermediate.growAggregate(prototype, paramSymbol, location);
        }
    }

    prototype->setOp(EOpPrototype);

    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(
    const TFunction &function,
    TIntermAggregate *functionParameters,
    TIntermBlock *functionBody,
    const TSourceLoc &location)
{
    // Check that non-void functions have at least one return statement.
    if (mCurrentFunctionType->getBasicType() != EbtVoid && !mFunctionReturnsValue)
    {
        error(location, "function does not return a value:", function.getName().c_str());
    }

    if (functionBody == nullptr)
    {
        functionBody = new TIntermBlock();
        functionBody->setLine(location);
    }
    TIntermFunctionDefinition *functionNode =
        new TIntermFunctionDefinition(function.getReturnType(), functionParameters, functionBody);
    functionNode->setLine(location);

    functionNode->getFunctionSymbolInfo()->setFromFunction(function);

    symbolTable.pop();
    return functionNode;
}

void TParseContext::parseFunctionDefinitionHeader(const TSourceLoc &location,
                                                  TFunction **function,
                                                  TIntermAggregate **aggregateOut)
{
    ASSERT(function);
    ASSERT(*function);
    const TSymbol *builtIn =
        symbolTable.findBuiltIn((*function)->getMangledName(), getShaderVersion());

    if (builtIn)
    {
        error(location, "built-in functions cannot be redefined", (*function)->getName().c_str());
    }
    else
    {
        TFunction *prevDec = static_cast<TFunction *>(
            symbolTable.find((*function)->getMangledName(), getShaderVersion()));

        // Note: 'prevDec' could be 'function' if this is the first time we've seen function as it
        // would have just been put in the symbol table. Otherwise, we're looking up an earlier
        // occurance.
        if (*function != prevDec)
        {
            // Swap the parameters of the previous declaration to the parameters of the function
            // definition (parameter names may differ).
            prevDec->swapParameters(**function);

            // The function definition will share the same symbol as any previous declaration.
            *function = prevDec;
        }

        if ((*function)->isDefined())
        {
            error(location, "function already has a body", (*function)->getName().c_str());
        }

        (*function)->setDefined();
    }

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

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

    //
    // Insert parameters into the symbol table.
    // If the parameter has no name, it's not an error, just don't insert it
    // (could be used for unused args).
    //
    // Also, accumulate the list of parameters into the HIL, so lower level code
    // knows where to find parameters.
    //
    TIntermAggregate *paramNodes = new TIntermAggregate;
    for (size_t i = 0; i < (*function)->getParamCount(); i++)
    {
        const TConstParameter &param = (*function)->getParam(i);
        if (param.name != 0)
        {
            TVariable *variable = new TVariable(param.name, *param.type);
            //
            // Insert the parameters with name in the symbol table.
            //
            if (!symbolTable.declare(variable))
            {
                error(location, "redefinition", variable->getName().c_str());
                paramNodes = intermediate.growAggregate(
                    paramNodes, intermediate.addSymbol(0, "", *param.type, location), location);
                continue;
            }

            //
            // Add the parameter to the HIL
            //
            TIntermSymbol *symbol = intermediate.addSymbol(
                variable->getUniqueId(), variable->getName(), variable->getType(), location);

            paramNodes = intermediate.growAggregate(paramNodes, symbol, location);
        }
        else
        {
            paramNodes = intermediate.growAggregate(
                paramNodes, intermediate.addSymbol(0, "", *param.type, location), location);
        }
    }
    intermediate.setAggregateOperator(paramNodes, EOpParameters, location);
    *aggregateOut = paramNodes;
    setLoopNestingLevel(0);
}

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.
    //
    // Return types and parameter qualifiers must match in all redeclarations, so those are checked
    // here.
    //
    TFunction *prevDec =
        static_cast<TFunction *>(symbolTable.find(function->getMangledName(), getShaderVersion()));

    if (getShaderVersion() >= 300 &&
        symbolTable.hasUnmangledBuiltInForShaderVersion(function->getName().c_str(),
                                                        getShaderVersion()))
    {
        // 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->getName().c_str());
    }
    else 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).type->getQualifier() !=
                function->getParam(i).type->getQualifier())
            {
                error(location,
                      "function must have the same parameter qualifiers in all of its declarations",
                      function->getParam(i).type->getQualifierString());
            }
        }
    }

    //
    // Check for previously declared variables using the same name.
    //
    TSymbol *prevSym = symbolTable.find(function->getName(), getShaderVersion());
    if (prevSym)
    {
        if (!prevSym->isFunction())
        {
            error(location, "redefinition of a function", function->getName().c_str());
        }
    }
    else
    {
        // Insert the unmangled name to detect potential future redefinition as a variable.
        symbolTable.getOuterLevel()->insertUnmangled(function);
    }

    // We're at the inner scope level of the function's arguments and body statement.
    // Add the function prototype to the surrounding scope instead.
    symbolTable.getOuterLevel()->insert(function);

    //
    // 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 TString *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 a sampler or an image is not involved as well...
    checkIsNotSampler(location, type.typeSpecifierNonArray,
                      "samplers can't be function return values");
    checkIsNotImage(location, type.typeSpecifierNonArray, "images can't be function return values");
    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.arraySize == 0 || mDiagnostics->numErrors() > 0);

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

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

TFunction *TParseContext::addConstructorFunc(const TPublicType &publicTypeIn)
{
    TPublicType publicType = publicTypeIn;
    if (publicType.isStructSpecifier())
    {
        error(publicType.getLine(), "constructor can't be a structure definition",
              getBasicString(publicType.getBasicType()));
    }

    TOperator op = EOpNull;
    if (publicType.getUserDef())
    {
        op = EOpConstructStruct;
    }
    else
    {
        op = sh::TypeToConstructorOperator(TType(publicType));
        if (op == EOpNull)
        {
            error(publicType.getLine(), "cannot construct this type",
                  getBasicString(publicType.getBasicType()));
            publicType.setBasicType(EbtFloat);
            op = EOpConstructFloat;
        }
    }

    TString tempString;
    const TType *type = new TType(publicType);
    return new TFunction(&tempString, type, op);
}

// 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(TIntermNode *arguments,
                                            TOperator op,
                                            TFunction *fnCall,
                                            const TSourceLoc &line)
{
    TType type = fnCall->getReturnType();
    if (type.isUnsizedArray())
    {
        if (fnCall->getParamCount() == 0)
        {
            error(line, "implicitly sized array constructor must have at least one argument", "[]");
            type.setArraySize(1u);
            return TIntermTyped::CreateZero(type);
        }
        type.setArraySize(static_cast<unsigned int>(fnCall->getParamCount()));
    }
    bool constType = true;
    for (size_t i = 0; i < fnCall->getParamCount(); ++i)
    {
        const TConstParameter &param = fnCall->getParam(i);
        if (param.type->getQualifier() != EvqConst)
            constType = false;
    }
    if (constType)
        type.setQualifier(EvqConst);

    if (!checkConstructorArguments(line, arguments, *fnCall, op, type))
    {
        TIntermTyped *dummyNode = intermediate.setAggregateOperator(nullptr, op, line);
        dummyNode->setType(type);
        return dummyNode;
    }
    TIntermAggregate *constructor = arguments->getAsAggregate();
    ASSERT(constructor != nullptr);

    // Turn the argument list itself into a constructor
    constructor->setOp(op);
    constructor->setLine(line);
    ASSERT(constructor->isConstructor());

    // Need to set type before setPrecisionFromChildren() because bool doesn't have precision.
    constructor->setType(type);

    // Structs should not be precision qualified, the individual members may be.
    // Built-in types on the other hand should be precision qualified.
    if (op != EOpConstructStruct)
    {
        constructor->setPrecisionFromChildren();
        type.setPrecision(constructor->getPrecision());
    }

    constructor->setType(type);

    TIntermTyped *constConstructor = intermediate.foldAggregateBuiltIn(constructor, mDiagnostics);
    if (constConstructor)
    {
        return constConstructor;
    }

    return constructor;
}

//
// Interface/uniform blocks
//
TIntermDeclaration *TParseContext::addInterfaceBlock(
    const TTypeQualifierBuilder &typeQualifierBuilder,
    const TSourceLoc &nameLine,
    const TString &blockName,
    TFieldList *fieldList,
    const TString *instanceName,
    const TSourceLoc &instanceLine,
    TIntermTyped *arrayIndex,
    const TSourceLoc &arrayIndexLine)
{
    checkIsNotReserved(nameLine, blockName);

    TTypeQualifier typeQualifier = typeQualifierBuilder.getVariableTypeQualifier(mDiagnostics);

    if (typeQualifier.qualifier != EvqUniform)
    {
        error(typeQualifier.line, "invalid qualifier: interface blocks must be uniform",
              getQualifierString(typeQualifier.qualifier));
    }

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

    checkIsMemoryQualifierNotSpecified(typeQualifier.memoryQualifier, typeQualifier.line);

    TLayoutQualifier blockLayoutQualifier = typeQualifier.layoutQualifier;
    checkLocationIsNotSpecified(typeQualifier.line, blockLayoutQualifier);

    if (blockLayoutQualifier.matrixPacking == EmpUnspecified)
    {
        blockLayoutQualifier.matrixPacking = mDefaultMatrixPacking;
    }

    if (blockLayoutQualifier.blockStorage == EbsUnspecified)
    {
        blockLayoutQualifier.blockStorage = mDefaultBlockStorage;
    }

    checkWorkGroupSizeIsNotSpecified(nameLine, blockLayoutQualifier);

    checkInternalFormatIsNotSpecified(nameLine, blockLayoutQualifier.imageInternalFormat);

    TSymbol *blockNameSymbol = new TInterfaceBlockName(&blockName);
    if (!symbolTable.declare(blockNameSymbol))
    {
        error(nameLine, "redefinition of an interface block name", blockName.c_str());
    }

    // 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 (IsSampler(fieldType->getBasicType()))
        {
            error(field->line(),
                  "unsupported type - sampler types are not allowed in interface blocks",
                  fieldType->getBasicString());
        }

        if (IsImage(fieldType->getBasicType()))
        {
            error(field->line(),
                  "unsupported type - image types are not allowed in interface blocks",
                  fieldType->getBasicString());
        }

        const TQualifier qualifier = fieldType->getQualifier();
        switch (qualifier)
        {
            case EvqGlobal:
            case EvqUniform:
                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();
        checkLocationIsNotSpecified(field->line(), fieldLayoutQualifier);

        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);
    }

    // add array index
    unsigned int arraySize = 0;
    if (arrayIndex != nullptr)
    {
        arraySize = checkIsValidArraySize(arrayIndexLine, arrayIndex);
    }

    TInterfaceBlock *interfaceBlock =
        new TInterfaceBlock(&blockName, fieldList, instanceName, arraySize, blockLayoutQualifier);
    TType interfaceBlockType(interfaceBlock, typeQualifier.qualifier, blockLayoutQualifier,
                             arraySize);

    TString symbolName = "";
    int symbolId       = 0;

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

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

            TVariable *fieldVariable = new TVariable(&field->name(), *fieldType);
            fieldVariable->setQualifier(typeQualifier.qualifier);

            if (!symbolTable.declare(fieldVariable))
            {
                error(field->line(), "redefinition of an interface block member name",
                      field->name().c_str());
            }
        }
    }
    else
    {
        checkIsNotReserved(instanceLine, *instanceName);

        // add a symbol for this interface block
        TVariable *instanceTypeDef = new TVariable(instanceName, interfaceBlockType, false);
        instanceTypeDef->setQualifier(typeQualifier.qualifier);

        if (!symbolTable.declare(instanceTypeDef))
        {
            error(instanceLine, "redefinition of an interface block instance name",
                  instanceName->c_str());
        }

        symbolId   = instanceTypeDef->getUniqueId();
        symbolName = instanceTypeDef->getName();
    }

    TIntermSymbol *blockSymbol =
        intermediate.addSymbol(symbolId, symbolName, interfaceBlockType, typeQualifier.line);
    TIntermDeclaration *declaration = new TIntermDeclaration();
    declaration->appendDeclarator(blockSymbol);
    declaration->setLine(nameLine);

    exitStructDeclaration();
    return declaration;
}

void TParseContext::enterStructDeclaration(const TSourceLoc &line, const TString &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;
        reasonStream << "Reference of struct type " << field.type()->getStruct()->name().c_str()
                     << " exceeds maximum allowed nesting level of " << kWebGLMaxStructNesting;
        std::string reason = reasonStream.str();
        error(line, reason.c_str(), field.name().c_str());
        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()->getSymbol().c_str());
        }
        else
        {
            error(location, " left of '[' is not of type array, matrix, or vector ", "expression");
        }

        TConstantUnion *unionArray = new TConstantUnion[1];
        unionArray->setFConst(0.0f);
        return intermediate.addConstantUnion(unionArray, TType(EbtFloat, EbpHigh, EvqConst),
                                             location);
    }

    TIntermConstantUnion *indexConstantUnion = indexExpression->getAsConstantUnion();

    // TODO(oetuaho@nvidia.com): Get rid of indexConstantUnion == nullptr below once ANGLE is able
    // to constant fold all constant expressions. Right now we don't allow indexing interface blocks
    // or fragment outputs with expressions that ANGLE is not able to constant fold, even if the
    // index is a constant expression.
    if (indexExpression->getQualifier() != EvqConst || indexConstantUnion == nullptr)
    {
        if (baseExpression->isInterfaceBlock())
        {
            error(location,
                  "array indexes for interface blocks arrays must be constant integral expressions",
                  "[");
        }
        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", "[");
        }
    }

    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                   = indexConstantUnion->getIConst(0);

        int safeIndex = -1;

        if (baseExpression->isArray())
        {
            if (baseExpression->getQualifier() == EvqFragData && index > 0)
            {
                if (mShaderSpec == SH_WEBGL2_SPEC)
                {
                    // Error has been already generated if index is not const.
                    if (indexExpression->getQualifier() == EvqConst)
                    {
                        error(location, "array index for gl_FragData must be constant zero", "[");
                    }
                    safeIndex = 0;
                }
                else if (!isExtensionEnabled("GL_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)
            {
                safeIndex = checkIndexOutOfRange(outOfRangeIndexIsError, location, index,
                                                 baseExpression->getArraySize(),
                                                 "array index out of range");
            }
        }
        else if (baseExpression->isMatrix())
        {
            safeIndex = checkIndexOutOfRange(outOfRangeIndexIsError, location, index,
                                             baseExpression->getType().getCols(),
                                             "matrix field selection out of range");
        }
        else if (baseExpression->isVector())
        {
            safeIndex = checkIndexOutOfRange(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)
        {
            TConstantUnion *safeConstantUnion = new TConstantUnion();
            safeConstantUnion->setIConst(safeIndex);
            indexConstantUnion->replaceConstantUnion(safeConstantUnion);
        }

        return intermediate.addIndex(EOpIndexDirect, baseExpression, indexExpression, location,
                                     mDiagnostics);
    }
    else
    {
        return intermediate.addIndex(EOpIndexIndirect, baseExpression, indexExpression, location,
                                     mDiagnostics);
    }
}

int TParseContext::checkIndexOutOfRange(bool outOfRangeIndexIsError,
                                        const TSourceLoc &location,
                                        int index,
                                        int arraySize,
                                        const char *reason)
{
    if (index >= arraySize || index < 0)
    {
        std::stringstream reasonStream;
        reasonStream << reason << " '" << index << "'";
        std::string token = reasonStream.str();
        outOfRangeError(outOfRangeIndexIsError, location, reason, "[]");
        if (index < 0)
        {
            return 0;
        }
        else
        {
            return arraySize - 1;
        }
    }
    return index;
}

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

    if (baseExpression->isVector())
    {
        TVectorFields fields;
        if (!parseVectorFields(fieldString, baseExpression->getNominalSize(), fields,
                               fieldLocation))
        {
            fields.num        = 1;
            fields.offsets[0] = 0;
        }

        return TIntermediate::AddSwizzle(baseExpression, fields, dotLocation);
    }
    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 = TIntermTyped::CreateIndexNode(i);
                index->setLine(fieldLocation);
                return intermediate.addIndex(EOpIndexDirectStruct, baseExpression, index,
                                             dotLocation, mDiagnostics);
            }
            else
            {
                error(dotLocation, " no such field in structure", fieldString.c_str());
                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 = TIntermTyped::CreateIndexNode(i);
                index->setLine(fieldLocation);
                return intermediate.addIndex(EOpIndexDirectInterfaceBlock, baseExpression, index,
                                             dotLocation, mDiagnostics);
            }
            else
            {
                error(dotLocation, " no such field in interface block", fieldString.c_str());
                return baseExpression;
            }
        }
    }
    else
    {
        if (mShaderVersion < 300)
        {
            error(dotLocation, " field selection requires structure or vector on left hand side",
                  fieldString.c_str());
        }
        else
        {
            error(dotLocation,
                  " field selection requires structure, vector, or interface block on left hand "
                  "side",
                  fieldString.c_str());
        }
        return baseExpression;
    }
}

TLayoutQualifier TParseContext::parseLayoutQualifier(const TString &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 == "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.c_str());
    }
    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
    {
        error(qualifierTypeLine, "invalid layout qualifier", qualifierType.c_str());
    }

    return qualifier;
}

void TParseContext::parseLocalSize(const TString &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;
        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;
}

TLayoutQualifier TParseContext::parseLayoutQualifier(const TString &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 == "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
    {
        error(qualifierTypeLine, "invalid layout qualifier", qualifierType.c_str());
    }

    return qualifier;
}

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

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

TFieldList *TParseContext::combineStructFieldLists(TFieldList *processedFields,
                                                   const TFieldList *newlyAddedFields,
                                                   const TSourceLoc &location)
{
    for (TField *field : *newlyAddedFields)
    {
        for (TField *oldField : *processedFields)
        {
            if (oldField->name() == field->name())
            {
                error(location, "duplicate field name in structure", field->name().c_str());
            }
        }
        processedFields->push_back(field);
    }
    return processedFields;
}

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

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

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

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

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

    for (unsigned int i = 0; i < fieldList->size(); ++i)
    {
        //
        // Careful not to replace already known aspects of type, like array-ness
        //
        TType *type = (*fieldList)[i]->type();
        type->setBasicType(typeSpecifier.getBasicType());
        type->setPrimarySize(typeSpecifier.getPrimarySize());
        type->setSecondarySize(typeSpecifier.getSecondarySize());
        type->setPrecision(typeSpecifier.precision);
        type->setQualifier(typeSpecifier.qualifier);
        type->setLayoutQualifier(typeSpecifier.layoutQualifier);
        type->setMemoryQualifier(typeSpecifier.memoryQualifier);
        type->setInvariant(typeSpecifier.invariant);

        // don't allow arrays of arrays
        if (type->isArray())
        {
            checkIsValidTypeForArray(typeSpecifier.getLine(), typeSpecifier);
        }
        if (typeSpecifier.array)
            type->setArraySize(static_cast<unsigned int>(typeSpecifier.arraySize));
        if (typeSpecifier.getUserDef())
        {
            type->setStruct(typeSpecifier.getUserDef()->getStruct());
        }

        checkIsBelowStructNestingLimit(typeSpecifier.getLine(), *(*fieldList)[i]);
    }

    return fieldList;
}

TTypeSpecifierNonArray TParseContext::addStructure(const TSourceLoc &structLine,
                                                   const TSourceLoc &nameLine,
                                                   const TString *structName,
                                                   TFieldList *fieldList)
{
    TStructure *structure = new TStructure(structName, fieldList);
    TType *structureType  = new TType(structure);

    // 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 (!structName->empty())
    {
        checkIsNotReserved(nameLine, *structName);
        TVariable *userTypeDef = new TVariable(structName, *structureType, true);
        if (!symbolTable.declare(userTypeDef))
        {
            error(nameLine, "redefinition of a struct", structName->c_str());
        }
    }

    // ensure we do not specify any storage qualifiers on the struct members
    for (unsigned int typeListIndex = 0; typeListIndex < fieldList->size(); typeListIndex++)
    {
        const 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");
        }
        if (IsImage(field.type()->getBasicType()))
        {
            error(field.line(), "disallowed type in struct", field.type()->getBasicString());
        }

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

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

    TTypeSpecifierNonArray typeSpecifierNonArray;
    typeSpecifierNonArray.initialize(EbtStruct, structLine);
    typeSpecifierNonArray.userDef           = structureType;
    typeSpecifierNonArray.isStructSpecifier = true;
    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;
    }

    if (statementList)
    {
        if (!ValidateSwitchStatementList(switchType, mDiagnostics, statementList, loc))
        {
            return nullptr;
        }
    }

    TIntermSwitch *node = intermediate.addSwitch(init, statementList, loc);
    if (node == nullptr)
    {
        error(loc, "erroneous switch statement", "switch");
        return nullptr;
    }
    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();
    // TODO(oetuaho@nvidia.com): Get rid of the conditionConst == nullptr check once all constant
    // expressions can be folded. Right now we don't allow constant expressions that ANGLE can't
    // fold in case labels.
    if (condition->getQualifier() != EvqConst || conditionConst == nullptr)
    {
        error(condition->getLine(), "case label must be constant", "case");
    }
    TIntermCase *node = intermediate.addCase(condition, loc);
    if (node == nullptr)
    {
        error(loc, "erroneous case statement", "case");
        return nullptr;
    }
    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 = intermediate.addCase(nullptr, loc);
    if (node == nullptr)
    {
        error(loc, "erroneous default statement", "default");
        return nullptr;
    }
    return node;
}

TIntermTyped *TParseContext::createUnaryMath(TOperator op,
                                             TIntermTyped *child,
                                             const TSourceLoc &loc,
                                             const TType *funcReturnType)
{
    if (child == nullptr)
    {
        return nullptr;
    }

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

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

    TIntermTyped *foldedNode = node->fold(mDiagnostics);
    if (foldedNode)
        return foldedNode;

    return node;
}

TIntermTyped *TParseContext::addUnaryMath(TOperator op, TIntermTyped *child, const TSourceLoc &loc)
{
    TIntermTyped *node = createUnaryMath(op, child, loc, nullptr);
    if (node == nullptr)
    {
        unaryOpError(loc, GetOperatorString(op), child->getCompleteString());
        return child;
    }
    return node;
}

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

bool TParseContext::binaryOpCommonCheck(TOperator op,
                                        TIntermTyped *left,
                                        TIntermTyped *right,
                                        const TSourceLoc &loc)
{
    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->isArray() || right->isArray())
    {
        if (mShaderVersion < 300)
        {
            error(loc, "Invalid operation for arrays", GetOperatorString(op));
            return false;
        }

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

    // GLSL ES 1.00 and 3.00 do not support implicit type casting.
    // So the basic type should usually match.
    if (!isBitShift && left->getBasicType() != right->getBasicType())
    {
        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 ((op == EOpAssign || op == EOpInitialize) &&
                left->getType().isStructureContainingImages())
            {
                error(loc, "undefined operation for structs containing images",
                      GetOperatorString(op));
                return false;
            }
        case EOpLessThan:
        case EOpGreaterThan:
        case EOpLessThanEqual:
        case EOpGreaterThanEqual:
            if ((left->getNominalSize() != right->getNominalSize()) ||
                (left->getSecondarySize() != right->getSecondarySize()))
            {
                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:
            break;
        case EOpLessThan:
        case EOpGreaterThan:
        case EOpLessThanEqual:
        case EOpGreaterThanEqual:
            ASSERT(!left->isArray() && !right->isArray() && !left->getType().getStruct() &&
                   !right->getType().getStruct());
            if (left->isMatrix() || left->isVector())
            {
                return nullptr;
            }
            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);
    node->setLine(loc);

    // See if we can fold constants.
    TIntermTyped *foldedNode = node->fold(mDiagnostics);
    if (foldedNode)
        return foldedNode;

    return 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->getCompleteString(),
                      right->getCompleteString());
        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 == 0)
    {
        binaryOpError(loc, GetOperatorString(op), left->getCompleteString(),
                      right->getCompleteString());
        TConstantUnion *unionArray = new TConstantUnion[1];
        unionArray->setBConst(false);
        return intermediate.addConstantUnion(unionArray, TType(EbtBool, EbpUndefined, EvqConst),
                                             loc);
    }
    return node;
}

TIntermBinary *TParseContext::createAssign(TOperator op,
                                           TIntermTyped *left,
                                           TIntermTyped *right,
                                           const TSourceLoc &loc)
{
    if (binaryOpCommonCheck(op, left, right, loc))
    {
        if (op == EOpMulAssign)
        {
            op = TIntermBinary::GetMulAssignOpBasedOnOperands(left->getType(), right->getType());
            if (!isMultiplicationTypeCombinationValid(op, left->getType(), right->getType()))
            {
                return nullptr;
            }
        }
        TIntermBinary *node = new TIntermBinary(op, left, right);
        node->setLine(loc);

        return node;
    }
    return nullptr;
}

TIntermTyped *TParseContext::addAssign(TOperator op,
                                       TIntermTyped *left,
                                       TIntermTyped *right,
                                       const TSourceLoc &loc)
{
    TIntermTyped *node = createAssign(op, left, right, loc);
    if (node == nullptr)
    {
        assignError(loc, "assign", left->getCompleteString(), right->getCompleteString());
        return left;
    }
    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",
              ",");
    }

    return TIntermediate::AddComma(left, right, loc, mShaderVersion);
}

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;
        default:
            // No checks for discard
            break;
    }
    return intermediate.addBranch(op, loc);
}

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

void TParseContext::checkTextureOffsetConst(TIntermAggregate *functionCall)
{
    ASSERT(!functionCall->isUserDefined());
    const TString &name        = functionCall->getFunctionSymbolInfo()->getName();
    TIntermNode *offset        = nullptr;
    TIntermSequence *arguments = functionCall->getSequence();
    if (name.compare(0, 16, "texelFetchOffset") == 0 ||
        name.compare(0, 16, "textureLodOffset") == 0 ||
        name.compare(0, 20, "textureProjLodOffset") == 0 ||
        name.compare(0, 17, "textureGradOffset") == 0 ||
        name.compare(0, 21, "textureProjGradOffset") == 0)
    {
        offset = arguments->back();
    }
    else if (name.compare(0, 13, "textureOffset") == 0 ||
             name.compare(0, 17, "textureProjOffset") == 0)
    {
        // A bias parameter might follow the offset parameter.
        ASSERT(arguments->size() >= 3);
        offset = (*arguments)[2];
    }
    if (offset != nullptr)
    {
        TIntermConstantUnion *offsetConstantUnion = offset->getAsConstantUnion();
        if (offset->getAsTyped()->getQualifier() != EvqConst || !offsetConstantUnion)
        {
            TString unmangledName = TFunction::unmangleName(name);
            error(functionCall->getLine(), "Texture offset must be a constant expression",
                  unmangledName.c_str());
        }
        else
        {
            ASSERT(offsetConstantUnion->getBasicType() == EbtInt);
            size_t size                  = offsetConstantUnion->getType().getObjectSize();
            const TConstantUnion *values = offsetConstantUnion->getUnionArrayPointer();
            for (size_t i = 0u; i < size; ++i)
            {
                int offsetValue = values[i].getIConst();
                if (offsetValue > mMaxProgramTexelOffset || offsetValue < mMinProgramTexelOffset)
                {
                    std::stringstream tokenStream;
                    tokenStream << offsetValue;
                    std::string token = tokenStream.str();
                    error(offset->getLine(), "Texture offset value out of valid range",
                          token.c_str());
                }
            }
        }
    }
}

// GLSL ES 3.10 Revision 4, 4.9 Memory Access Qualifiers
void TParseContext::checkImageMemoryAccessForBuiltinFunctions(TIntermAggregate *functionCall)
{
    ASSERT(!functionCall->isUserDefined());
    const TString &name = functionCall->getFunctionSymbolInfo()->getName();

    if (name.compare(0, 5, "image") == 0)
    {
        TIntermSequence *arguments = functionCall->getSequence();
        TIntermNode *imageNode     = (*arguments)[0];
        TIntermSymbol *imageSymbol = imageNode->getAsSymbolNode();

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

        if (name.compare(5, 5, "Store") == 0)
        {
            if (memoryQualifier.readonly)
            {
                error(imageNode->getLine(),
                      "'imageStore' cannot be used with images qualified as 'readonly'",
                      imageSymbol->getSymbol().c_str());
            }
        }
        else if (name.compare(5, 4, "Load") == 0)
        {
            if (memoryQualifier.writeonly)
            {
                error(imageNode->getLine(),
                      "'imageLoad' cannot be used with images qualified as 'writeonly'",
                      imageSymbol->getSymbol().c_str());
            }
        }
    }
}

// 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->isUserDefined());

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

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

    for (size_t i = 0; i < arguments.size(); ++i)
    {
        const TType &functionArgumentType  = arguments[i]->getAsTyped()->getType();
        const TType &functionParameterType = *functionDefinition->getParam(i).type;
        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",
                      arguments[i]->getAsSymbolNode()->getSymbol().c_str());
            }

            if (functionArgumentMemoryQualifier.writeonly &&
                !functionParameterMemoryQualifier.writeonly)
            {
                error(functionCall->getLine(),
                      "Function call discards the 'writeonly' qualifier from image",
                      arguments[i]->getAsSymbolNode()->getSymbol().c_str());
            }

            if (functionArgumentMemoryQualifier.coherent &&
                !functionParameterMemoryQualifier.coherent)
            {
                error(functionCall->getLine(),
                      "Function call discards the 'coherent' qualifier from image",
                      arguments[i]->getAsSymbolNode()->getSymbol().c_str());
            }

            if (functionArgumentMemoryQualifier.volatileQualifier &&
                !functionParameterMemoryQualifier.volatileQualifier)
            {
                error(functionCall->getLine(),
                      "Function call discards the 'volatile' qualifier from image",
                      arguments[i]->getAsSymbolNode()->getSymbol().c_str());
            }
        }
    }
}

TIntermTyped *TParseContext::addFunctionCallOrMethod(TFunction *fnCall,
                                                     TIntermNode *paramNode,
                                                     TIntermNode *thisNode,
                                                     const TSourceLoc &loc,
                                                     bool *fatalError)
{
    *fatalError            = false;
    TOperator op           = fnCall->getBuiltInOp();
    TIntermTyped *callNode = nullptr;

    if (thisNode != nullptr)
    {
        TConstantUnion *unionArray = new TConstantUnion[1];
        int arraySize              = 0;
        TIntermTyped *typedThis    = thisNode->getAsTyped();
        if (fnCall->getName() != "length")
        {
            error(loc, "invalid method", fnCall->getName().c_str());
        }
        else if (paramNode != nullptr)
        {
            error(loc, "method takes no parameters", "length");
        }
        else if (typedThis == nullptr || !typedThis->isArray())
        {
            error(loc, "length can only be called on arrays", "length");
        }
        else
        {
            arraySize = typedThis->getArraySize();
            if (typedThis->getAsSymbolNode() == nullptr)
            {
                // This code path can be hit with expressions like these:
                // (a = b).length()
                // (func()).length()
                // (int[3](0, 1, 2)).length()
                // ESSL 3.00 section 5.9 defines expressions so that this is not actually a valid
                // expression.
                // It allows "An array name with the length method applied" in contrast to GLSL 4.4
                // spec section 5.9 which allows "An array, vector or matrix expression with the
                // length method applied".
                error(loc, "length can only be called on array names, not on array expressions",
                      "length");
            }
        }
        unionArray->setIConst(arraySize);
        callNode =
            intermediate.addConstantUnion(unionArray, TType(EbtInt, EbpUndefined, EvqConst), loc);
    }
    else if (op != EOpNull)
    {
        // Then this should be a constructor.
        callNode = addConstructor(paramNode, op, fnCall, loc);
    }
    else
    {
        //
        // Not a constructor.  Find it in the symbol table.
        //
        const TFunction *fnCandidate;
        bool builtIn;
        fnCandidate = findFunction(loc, fnCall, mShaderVersion, &builtIn);
        if (fnCandidate)
        {
            //
            // A declared function.
            //
            if (builtIn && !fnCandidate->getExtension().empty())
            {
                checkCanUseExtension(loc, fnCandidate->getExtension());
            }
            op = fnCandidate->getBuiltInOp();
            if (builtIn && op != EOpNull)
            {
                //
                // A function call mapped to a built-in operation.
                //
                if (fnCandidate->getParamCount() == 1)
                {
                    //
                    // Treat it like a built-in unary operator.
                    //
                    TIntermAggregate *paramAgg = paramNode->getAsAggregate();
                    paramNode                  = paramAgg->getSequence()->front();
                    callNode                   = createUnaryMath(op, paramNode->getAsTyped(), loc,
                                               &fnCandidate->getReturnType());
                    if (callNode == nullptr)
                    {
                        std::stringstream reasonStream;
                        reasonStream << "wrong operand type for built in unary function: "
                                     << static_cast<TIntermTyped *>(paramNode)->getCompleteString();
                        std::string reason = reasonStream.str();
                        error(paramNode->getLine(), reason.c_str(), "Internal Error");
                        *fatalError = true;
                        return nullptr;
                    }
                }
                else
                {
                    TIntermAggregate *aggregate =
                        intermediate.setAggregateOperator(paramNode, op, loc);
                    aggregate->setType(fnCandidate->getReturnType());
                    aggregate->setPrecisionFromChildren();
                    if (aggregate->areChildrenConstQualified())
                    {
                        aggregate->getTypePointer()->setQualifier(EvqConst);
                    }

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

                    // See if we can constant fold a built-in. Note that this may be possible even
                    // if it is not const-qualified.
                    TIntermTyped *foldedNode =
                        intermediate.foldAggregateBuiltIn(aggregate, mDiagnostics);
                    if (foldedNode)
                    {
                        callNode = foldedNode;
                    }
                    else
                    {
                        callNode = aggregate;
                    }
                }
            }
            else
            {
                // This is a real function call
                TIntermAggregate *aggregate =
                    intermediate.setAggregateOperator(paramNode, EOpFunctionCall, loc);
                aggregate->setType(fnCandidate->getReturnType());

                // this is how we know whether the given function is a builtIn function or a user
                // defined function
                // if builtIn == false, it's a userDefined -> could be an overloaded
                // builtIn function also
                // if builtIn == true, it's definitely a builtIn function with EOpNull
                if (!builtIn)
                    aggregate->setUserDefined();
                aggregate->getFunctionSymbolInfo()->setFromFunction(*fnCandidate);

                // This needs to happen after the function info including name is set
                if (builtIn)
                {
                    aggregate->setBuiltInFunctionPrecision();

                    checkTextureOffsetConst(aggregate);

                    checkImageMemoryAccessForBuiltinFunctions(aggregate);
                }
                else
                {
                    checkImageMemoryAccessForUserDefinedFunctions(fnCandidate, aggregate);
                }

                callNode = aggregate;

                functionCallLValueErrorCheck(fnCandidate, aggregate);
            }
        }
        else
        {
            // error message was put out by findFunction()
            // Put on a dummy node for error recovery
            TConstantUnion *unionArray = new TConstantUnion[1];
            unionArray->setFConst(0.0f);
            callNode = intermediate.addConstantUnion(unionArray,
                                                     TType(EbtFloat, EbpUndefined, EvqConst), loc);
        }
    }
    return callNode;
}

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

    if (trueExpression->getType() != falseExpression->getType())
    {
        binaryOpError(loc, ":", trueExpression->getCompleteString(),
                      falseExpression->getCompleteString());
        return falseExpression;
    }
    if (IsOpaqueType(trueExpression->getBasicType()))
    {
        // ESSL 1.00 section 4.1.7
        // ESSL 3.00 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;
    }

    // ESSL1 sections 5.2 and 5.7:
    // ESSL3 section 5.7:
    // Ternary operator is not among the operators allowed for structures/arrays.
    if (trueExpression->isArray() || trueExpression->getBasicType() == EbtStruct)
    {
        error(loc, "ternary operator is not allowed for structures or arrays", ":");
        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;
    }

    return TIntermediate::AddTernarySelection(cond, trueExpression, falseExpression, loc);
}

//
// 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 == NULL))
        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
