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

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• Hash : d9fa0744
  Author :
  Date : 2019-04-25T14:57:26
  

  Emit OVR_multiview2 on ESSL/GLSL outputs.
  
  Add ARB_shader_viewport_layer_array support to
  SH_SELECT_VIEW_IN_NV_GLSL_VERTEX_SHADER.
  
  Bug: angleproject:3404
  Change-Id: Ia89517d0cc92400ce47c9118e8c1abf8285aec41
  Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1585452
  Reviewed-by: Jamie Madill <jmadill@chromium.org>
  

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• src/compiler/translator/Compiler.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/Compiler.h"
  
  #include <sstream>
  
  #include "angle_gl.h"
  #include "common/utilities.h"
  #include "compiler/translator/CallDAG.h"
  #include "compiler/translator/CollectVariables.h"
  #include "compiler/translator/Initialize.h"
  #include "compiler/translator/IsASTDepthBelowLimit.h"
  #include "compiler/translator/OutputTree.h"
  #include "compiler/translator/ParseContext.h"
  #include "compiler/translator/ValidateLimitations.h"
  #include "compiler/translator/ValidateMaxParameters.h"
  #include "compiler/translator/ValidateOutputs.h"
  #include "compiler/translator/ValidateVaryingLocations.h"
  #include "compiler/translator/VariablePacker.h"
  #include "compiler/translator/tree_ops/AddAndTrueToLoopCondition.h"
  #include "compiler/translator/tree_ops/ClampFragDepth.h"
  #include "compiler/translator/tree_ops/ClampPointSize.h"
  #include "compiler/translator/tree_ops/DeclareAndInitBuiltinsForInstancedMultiview.h"
  #include "compiler/translator/tree_ops/DeferGlobalInitializers.h"
  #include "compiler/translator/tree_ops/EmulateGLDrawID.h"
  #include "compiler/translator/tree_ops/EmulateGLFragColorBroadcast.h"
  #include "compiler/translator/tree_ops/EmulatePrecision.h"
  #include "compiler/translator/tree_ops/FoldExpressions.h"
  #include "compiler/translator/tree_ops/InitializeVariables.h"
  #include "compiler/translator/tree_ops/PruneEmptyCases.h"
  #include "compiler/translator/tree_ops/PruneNoOps.h"
  #include "compiler/translator/tree_ops/RegenerateStructNames.h"
  #include "compiler/translator/tree_ops/RemoveArrayLengthMethod.h"
  #include "compiler/translator/tree_ops/RemoveInvariantDeclaration.h"
  #include "compiler/translator/tree_ops/RemovePow.h"
  #include "compiler/translator/tree_ops/RemoveUnreferencedVariables.h"
  #include "compiler/translator/tree_ops/RewriteDoWhile.h"
  #include "compiler/translator/tree_ops/RewriteRepeatedAssignToSwizzled.h"
  #include "compiler/translator/tree_ops/ScalarizeVecAndMatConstructorArgs.h"
  #include "compiler/translator/tree_ops/SeparateDeclarations.h"
  #include "compiler/translator/tree_ops/SimplifyLoopConditions.h"
  #include "compiler/translator/tree_ops/SplitSequenceOperator.h"
  #include "compiler/translator/tree_ops/UnfoldShortCircuitAST.h"
  #include "compiler/translator/tree_ops/UseInterfaceBlockFields.h"
  #include "compiler/translator/tree_ops/VectorizeVectorScalarArithmetic.h"
  #include "compiler/translator/tree_util/BuiltIn_autogen.h"
  #include "compiler/translator/tree_util/IntermNodePatternMatcher.h"
  #include "compiler/translator/tree_util/ReplaceShadowingVariables.h"
  #include "compiler/translator/util.h"
  #include "third_party/compiler/ArrayBoundsClamper.h"
  
  namespace sh
  {
  
  namespace
  {
  
  #if defined(ANGLE_ENABLE_FUZZER_CORPUS_OUTPUT)
  void DumpFuzzerCase(char const *const *shaderStrings,
                      size_t numStrings,
                      uint32_t type,
                      uint32_t spec,
                      uint32_t output,
                      uint64_t options)
  {
      static int fileIndex = 0;
  
      std::ostringstream o = sh::InitializeStream<std::ostringstream>();
      o << "corpus/" << fileIndex++ << ".sample";
      std::string s = o.str();
  
      // Must match the input format of the fuzzer
      FILE *f = fopen(s.c_str(), "w");
      fwrite(&type, sizeof(type), 1, f);
      fwrite(&spec, sizeof(spec), 1, f);
      fwrite(&output, sizeof(output), 1, f);
      fwrite(&options, sizeof(options), 1, f);
  
      char zero[128 - 20] = {0};
      fwrite(&zero, 128 - 20, 1, f);
  
      for (size_t i = 0; i < numStrings; i++)
      {
          fwrite(shaderStrings[i], sizeof(char), strlen(shaderStrings[i]), f);
      }
      fwrite(&zero, 1, 1, f);
  
      fclose(f);
  }
  #endif  // defined(ANGLE_ENABLE_FUZZER_CORPUS_OUTPUT)
  }  // anonymous namespace
  
  bool IsGLSL130OrNewer(ShShaderOutput output)
  {
      return (output == SH_GLSL_130_OUTPUT || output == SH_GLSL_140_OUTPUT ||
              output == SH_GLSL_150_CORE_OUTPUT || output == SH_GLSL_330_CORE_OUTPUT ||
              output == SH_GLSL_400_CORE_OUTPUT || output == SH_GLSL_410_CORE_OUTPUT ||
              output == SH_GLSL_420_CORE_OUTPUT || output == SH_GLSL_430_CORE_OUTPUT ||
              output == SH_GLSL_440_CORE_OUTPUT || output == SH_GLSL_450_CORE_OUTPUT);
  }
  
  bool IsGLSL420OrNewer(ShShaderOutput output)
  {
      return (output == SH_GLSL_420_CORE_OUTPUT || output == SH_GLSL_430_CORE_OUTPUT ||
              output == SH_GLSL_440_CORE_OUTPUT || output == SH_GLSL_450_CORE_OUTPUT);
  }
  
  bool IsGLSL410OrOlder(ShShaderOutput output)
  {
      return (output == SH_GLSL_130_OUTPUT || output == SH_GLSL_140_OUTPUT ||
              output == SH_GLSL_150_CORE_OUTPUT || output == SH_GLSL_330_CORE_OUTPUT ||
              output == SH_GLSL_400_CORE_OUTPUT || output == SH_GLSL_410_CORE_OUTPUT);
  }
  
  bool RemoveInvariant(sh::GLenum shaderType,
                       int shaderVersion,
                       ShShaderOutput outputType,
                       ShCompileOptions compileOptions)
  {
      if (shaderType == GL_FRAGMENT_SHADER && IsGLSL420OrNewer(outputType))
          return true;
  
      if ((compileOptions & SH_REMOVE_INVARIANT_AND_CENTROID_FOR_ESSL3) != 0 &&
          shaderVersion >= 300 && shaderType == GL_VERTEX_SHADER)
          return true;
  
      return false;
  }
  
  size_t GetGlobalMaxTokenSize(ShShaderSpec spec)
  {
      // WebGL defines a max token length of 256, while ES2 leaves max token
      // size undefined. ES3 defines a max size of 1024 characters.
      switch (spec)
      {
          case SH_WEBGL_SPEC:
              return 256;
          default:
              return 1024;
      }
  }
  
  int GetMaxUniformVectorsForShaderType(GLenum shaderType, const ShBuiltInResources &resources)
  {
      switch (shaderType)
      {
          case GL_VERTEX_SHADER:
              return resources.MaxVertexUniformVectors;
          case GL_FRAGMENT_SHADER:
              return resources.MaxFragmentUniformVectors;
  
          // TODO (jiawei.shao@intel.com): check if we need finer-grained component counting
          case GL_COMPUTE_SHADER:
              return resources.MaxComputeUniformComponents / 4;
          case GL_GEOMETRY_SHADER_EXT:
              return resources.MaxGeometryUniformComponents / 4;
          default:
              UNREACHABLE();
              return -1;
      }
  }
  
  namespace
  {
  
  class TScopedPoolAllocator
  {
    public:
      TScopedPoolAllocator(angle::PoolAllocator *allocator) : mAllocator(allocator)
      {
          mAllocator->push();
          SetGlobalPoolAllocator(mAllocator);
      }
      ~TScopedPoolAllocator()
      {
          SetGlobalPoolAllocator(nullptr);
          mAllocator->pop();
      }
  
    private:
      angle::PoolAllocator *mAllocator;
  };
  
  class TScopedSymbolTableLevel
  {
    public:
      TScopedSymbolTableLevel(TSymbolTable *table) : mTable(table)
      {
          ASSERT(mTable->isEmpty());
          mTable->push();
      }
      ~TScopedSymbolTableLevel()
      {
          while (!mTable->isEmpty())
              mTable->pop();
      }
  
    private:
      TSymbolTable *mTable;
  };
  
  int MapSpecToShaderVersion(ShShaderSpec spec)
  {
      switch (spec)
      {
          case SH_GLES2_SPEC:
          case SH_WEBGL_SPEC:
              return 100;
          case SH_GLES3_SPEC:
          case SH_WEBGL2_SPEC:
              return 300;
          case SH_GLES3_1_SPEC:
          case SH_WEBGL3_SPEC:
              return 310;
          default:
              UNREACHABLE();
              return 0;
      }
  }
  
  bool ValidateFragColorAndFragData(GLenum shaderType,
                                    int shaderVersion,
                                    const TSymbolTable &symbolTable,
                                    TDiagnostics *diagnostics)
  {
      if (shaderVersion > 100 || shaderType != GL_FRAGMENT_SHADER)
      {
          return true;
      }
  
      bool usesFragColor = false;
      bool usesFragData  = false;
      // This validation is a bit stricter than the spec - it's only an error to write to
      // both FragData and FragColor. But because it's better not to have reads from undefined
      // variables, we always return an error if they are both referenced, rather than only if they
      // are written.
      if (symbolTable.isStaticallyUsed(*BuiltInVariable::gl_FragColor()) ||
          symbolTable.isStaticallyUsed(*BuiltInVariable::gl_SecondaryFragColorEXT()))
      {
          usesFragColor = true;
      }
      // Extension variables may not always be initialized (saves some time at symbol table init).
      bool secondaryFragDataUsed =
          symbolTable.gl_SecondaryFragDataEXT() != nullptr &&
          symbolTable.isStaticallyUsed(*symbolTable.gl_SecondaryFragDataEXT());
      if (symbolTable.isStaticallyUsed(*symbolTable.gl_FragData()) || secondaryFragDataUsed)
      {
          usesFragData = true;
      }
      if (usesFragColor && usesFragData)
      {
          const char *errorMessage = "cannot use both gl_FragData and gl_FragColor";
          if (symbolTable.isStaticallyUsed(*BuiltInVariable::gl_SecondaryFragColorEXT()) ||
              secondaryFragDataUsed)
          {
              errorMessage =
                  "cannot use both output variable sets (gl_FragData, gl_SecondaryFragDataEXT)"
                  " and (gl_FragColor, gl_SecondaryFragColorEXT)";
          }
          diagnostics->globalError(errorMessage);
          return false;
      }
      return true;
  }
  
  }  // namespace
  
  TShHandleBase::TShHandleBase()
  {
      allocator.push();
      SetGlobalPoolAllocator(&allocator);
  }
  
  TShHandleBase::~TShHandleBase()
  {
      SetGlobalPoolAllocator(nullptr);
      allocator.popAll();
  }
  
  TCompiler::TCompiler(sh::GLenum type, ShShaderSpec spec, ShShaderOutput output)
      : mVariablesCollected(false),
        mGLPositionInitialized(false),
        mShaderType(type),
        mShaderSpec(spec),
        mOutputType(output),
        mBuiltInFunctionEmulator(),
        mDiagnostics(mInfoSink.info),
        mSourcePath(nullptr),
        mComputeShaderLocalSizeDeclared(false),
        mComputeShaderLocalSize(1),
        mGeometryShaderMaxVertices(-1),
        mGeometryShaderInvocations(0),
        mGeometryShaderInputPrimitiveType(EptUndefined),
        mGeometryShaderOutputPrimitiveType(EptUndefined)
  {}
  
  TCompiler::~TCompiler() {}
  
  bool TCompiler::shouldRunLoopAndIndexingValidation(ShCompileOptions compileOptions) const
  {
      // If compiling an ESSL 1.00 shader for WebGL, or if its been requested through the API,
      // validate loop and indexing as well (to verify that the shader only uses minimal functionality
      // of ESSL 1.00 as in Appendix A of the spec).
      return (IsWebGLBasedSpec(mShaderSpec) && mShaderVersion == 100) ||
             (compileOptions & SH_VALIDATE_LOOP_INDEXING);
  }
  
  bool TCompiler::Init(const ShBuiltInResources &resources)
  {
      SetGlobalPoolAllocator(&allocator);
  
      // Generate built-in symbol table.
      if (!initBuiltInSymbolTable(resources))
          return false;
  
      mResources = resources;
      setResourceString();
  
      InitExtensionBehavior(resources, mExtensionBehavior);
      mArrayBoundsClamper.SetClampingStrategy(resources.ArrayIndexClampingStrategy);
      return true;
  }
  
  TIntermBlock *TCompiler::compileTreeForTesting(const char *const shaderStrings[],
                                                 size_t numStrings,
                                                 ShCompileOptions compileOptions)
  {
      return compileTreeImpl(shaderStrings, numStrings, compileOptions);
  }
  
  TIntermBlock *TCompiler::compileTreeImpl(const char *const shaderStrings[],
                                           size_t numStrings,
                                           const ShCompileOptions compileOptions)
  {
      clearResults();
  
      ASSERT(numStrings > 0);
      ASSERT(GetGlobalPoolAllocator());
  
      // Reset the extension behavior for each compilation unit.
      ResetExtensionBehavior(mExtensionBehavior);
  
      // If gl_DrawID is not supported, remove it from the available extensions
      // Currently we only allow emulation of gl_DrawID
      const bool glDrawIDSupported = (compileOptions & SH_EMULATE_GL_DRAW_ID) != 0u;
      if (!glDrawIDSupported)
      {
          auto it = mExtensionBehavior.find(TExtension::ANGLE_multi_draw);
          if (it != mExtensionBehavior.end())
          {
              mExtensionBehavior.erase(it);
          }
      }
  
      // First string is path of source file if flag is set. The actual source follows.
      size_t firstSource = 0;
      if (compileOptions & SH_SOURCE_PATH)
      {
          mSourcePath = shaderStrings[0];
          ++firstSource;
      }
  
      TParseContext parseContext(mSymbolTable, mExtensionBehavior, mShaderType, mShaderSpec, true,
                                 &mDiagnostics, getResources());
  
      parseContext.setFragmentPrecisionHighOnESSL1(mResources.FragmentPrecisionHigh == 1);
  
      // We preserve symbols at the built-in level from compile-to-compile.
      // Start pushing the user-defined symbols at global level.
      TScopedSymbolTableLevel globalLevel(&mSymbolTable);
      ASSERT(mSymbolTable.atGlobalLevel());
  
      // Parse shader.
      if (PaParseStrings(numStrings - firstSource, &shaderStrings[firstSource], nullptr,
                         &parseContext) != 0)
      {
          return nullptr;
      }
  
      if (parseContext.getTreeRoot() == nullptr)
      {
          return nullptr;
      }
  
      setASTMetadata(parseContext);
  
      if (!checkShaderVersion(&parseContext))
      {
          return nullptr;
      }
  
      TIntermBlock *root = parseContext.getTreeRoot();
      if (!checkAndSimplifyAST(root, parseContext, compileOptions))
      {
          return nullptr;
      }
  
      return root;
  }
  
  bool TCompiler::checkShaderVersion(TParseContext *parseContext)
  {
      if (MapSpecToShaderVersion(mShaderSpec) < mShaderVersion)
      {
          mDiagnostics.globalError("unsupported shader version");
          return false;
      }
  
      ASSERT(parseContext);
      switch (mShaderType)
      {
          case GL_COMPUTE_SHADER:
              if (mShaderVersion < 310)
              {
                  mDiagnostics.globalError("Compute shader is not supported in this shader version.");
                  return false;
              }
              break;
  
          case GL_GEOMETRY_SHADER_EXT:
              if (mShaderVersion < 310)
              {
                  mDiagnostics.globalError(
                      "Geometry shader is not supported in this shader version.");
                  return false;
              }
              else
              {
                  ASSERT(mShaderVersion == 310);
                  if (!parseContext->checkCanUseExtension(sh::TSourceLoc(),
                                                          TExtension::EXT_geometry_shader))
                  {
                      return false;
                  }
              }
              break;
  
          default:
              break;
      }
  
      return true;
  }
  
  void TCompiler::setASTMetadata(const TParseContext &parseContext)
  {
      mShaderVersion = parseContext.getShaderVersion();
  
      mPragma = parseContext.pragma();
      mSymbolTable.setGlobalInvariant(mPragma.stdgl.invariantAll);
  
      mComputeShaderLocalSizeDeclared = parseContext.isComputeShaderLocalSizeDeclared();
      mComputeShaderLocalSize         = parseContext.getComputeShaderLocalSize();
  
      mNumViews = parseContext.getNumViews();
  
      if (mShaderType == GL_GEOMETRY_SHADER_EXT)
      {
          mGeometryShaderInputPrimitiveType  = parseContext.getGeometryShaderInputPrimitiveType();
          mGeometryShaderOutputPrimitiveType = parseContext.getGeometryShaderOutputPrimitiveType();
          mGeometryShaderMaxVertices         = parseContext.getGeometryShaderMaxVertices();
          mGeometryShaderInvocations         = parseContext.getGeometryShaderInvocations();
      }
  }
  
  bool TCompiler::checkAndSimplifyAST(TIntermBlock *root,
                                      const TParseContext &parseContext,
                                      ShCompileOptions compileOptions)
  {
      // Disallow expressions deemed too complex.
      if ((compileOptions & SH_LIMIT_EXPRESSION_COMPLEXITY) && !limitExpressionComplexity(root))
      {
          return false;
      }
  
      if (shouldRunLoopAndIndexingValidation(compileOptions) &&
          !ValidateLimitations(root, mShaderType, &mSymbolTable, &mDiagnostics))
      {
          return false;
      }
  
      if (!ValidateFragColorAndFragData(mShaderType, mShaderVersion, mSymbolTable, &mDiagnostics))
      {
          return false;
      }
  
      // Fold expressions that could not be folded before validation that was done as a part of
      // parsing.
      FoldExpressions(root, &mDiagnostics);
      // Folding should only be able to generate warnings.
      ASSERT(mDiagnostics.numErrors() == 0);
      if (!ValidateAST(root, &mDiagnostics, mValidateASTOptions))
      {
          return false;
      }
  
      // We prune no-ops to work around driver bugs and to keep AST processing and output simple.
      // The following kinds of no-ops are pruned:
      //   1. Empty declarations "int;".
      //   2. Literal statements: "1.0;". The ESSL output doesn't define a default precision
      //      for float, so float literal statements would end up with no precision which is
      //      invalid ESSL.
      // After this empty declarations are not allowed in the AST.
      PruneNoOps(root, &mSymbolTable);
      if (!ValidateAST(root, &mDiagnostics, mValidateASTOptions))
      {
          return false;
      }
  
      // Create the function DAG and check there is no recursion
      if (!initCallDag(root))
      {
          return false;
      }
  
      if ((compileOptions & SH_LIMIT_CALL_STACK_DEPTH) && !checkCallDepth())
      {
          return false;
      }
  
      // Checks which functions are used and if "main" exists
      mFunctionMetadata.clear();
      mFunctionMetadata.resize(mCallDag.size());
      if (!tagUsedFunctions())
      {
          return false;
      }
  
      if (!(compileOptions & SH_DONT_PRUNE_UNUSED_FUNCTIONS))
      {
          pruneUnusedFunctions(root);
          if (!ValidateAST(root, &mDiagnostics, mValidateASTOptions))
          {
              return false;
          }
      }
      if (IsSpecWithFunctionBodyNewScope(mShaderSpec, mShaderVersion))
      {
          ReplaceShadowingVariables(root, &mSymbolTable);
      }
  
      if (mShaderVersion >= 310 && !ValidateVaryingLocations(root, &mDiagnostics, mShaderType))
      {
          return false;
      }
  
      if (mShaderVersion >= 300 && mShaderType == GL_FRAGMENT_SHADER &&
          !ValidateOutputs(root, getExtensionBehavior(), mResources.MaxDrawBuffers, &mDiagnostics))
      {
          return false;
      }
  
      // Fail compilation if precision emulation not supported.
      if (getResources().WEBGL_debug_shader_precision && getPragma().debugShaderPrecision &&
          !EmulatePrecision::SupportedInLanguage(mOutputType))
      {
          mDiagnostics.globalError("Precision emulation not supported for this output type.");
          return false;
      }
  
      // Clamping uniform array bounds needs to happen after validateLimitations pass.
      if (compileOptions & SH_CLAMP_INDIRECT_ARRAY_BOUNDS)
      {
          mArrayBoundsClamper.MarkIndirectArrayBoundsForClamping(root);
      }
  
      if ((compileOptions & SH_INITIALIZE_BUILTINS_FOR_INSTANCED_MULTIVIEW) &&
          (parseContext.isExtensionEnabled(TExtension::OVR_multiview2) ||
           parseContext.isExtensionEnabled(TExtension::OVR_multiview)) &&
          getShaderType() != GL_COMPUTE_SHADER)
      {
          DeclareAndInitBuiltinsForInstancedMultiview(root, mNumViews, mShaderType, compileOptions,
                                                      mOutputType, &mSymbolTable);
          if (!ValidateAST(root, &mDiagnostics, mValidateASTOptions))
          {
              return false;
          }
      }
  
      // This pass might emit short circuits so keep it before the short circuit unfolding
      if (compileOptions & SH_REWRITE_DO_WHILE_LOOPS)
      {
          RewriteDoWhile(root, &mSymbolTable);
          if (!ValidateAST(root, &mDiagnostics, mValidateASTOptions))
          {
              return false;
          }
      }
  
      if (compileOptions & SH_ADD_AND_TRUE_TO_LOOP_CONDITION)
      {
          AddAndTrueToLoopCondition(root);
          if (!ValidateAST(root, &mDiagnostics, mValidateASTOptions))
          {
              return false;
          }
      }
  
      if (compileOptions & SH_UNFOLD_SHORT_CIRCUIT)
      {
          UnfoldShortCircuitAST(root);
          if (!ValidateAST(root, &mDiagnostics, mValidateASTOptions))
          {
              return false;
          }
      }
  
      if (compileOptions & SH_REMOVE_POW_WITH_CONSTANT_EXPONENT)
      {
          RemovePow(root, &mSymbolTable);
          if (!ValidateAST(root, &mDiagnostics, mValidateASTOptions))
          {
              return false;
          }
      }
  
      if (compileOptions & SH_REGENERATE_STRUCT_NAMES)
      {
          RegenerateStructNames gen(&mSymbolTable);
          root->traverse(&gen);
          if (!ValidateAST(root, &mDiagnostics, mValidateASTOptions))
          {
              return false;
          }
      }
  
      if (mShaderType == GL_VERTEX_SHADER &&
          IsExtensionEnabled(mExtensionBehavior, TExtension::ANGLE_multi_draw))
      {
          if ((compileOptions & SH_EMULATE_GL_DRAW_ID) != 0)
          {
              EmulateGLDrawID(root, &mSymbolTable, &mUniforms,
                              shouldCollectVariables(compileOptions));
              if (!ValidateAST(root, &mDiagnostics, mValidateASTOptions))
              {
                  return false;
              }
          }
      }
  
      if (mShaderType == GL_FRAGMENT_SHADER && mShaderVersion == 100 && mResources.EXT_draw_buffers &&
          mResources.MaxDrawBuffers > 1 &&
          IsExtensionEnabled(mExtensionBehavior, TExtension::EXT_draw_buffers))
      {
          EmulateGLFragColorBroadcast(root, mResources.MaxDrawBuffers, &mOutputVariables,
                                      &mSymbolTable, mShaderVersion);
          if (!ValidateAST(root, &mDiagnostics, mValidateASTOptions))
          {
              return false;
          }
      }
  
      int simplifyScalarized = (compileOptions & SH_SCALARIZE_VEC_AND_MAT_CONSTRUCTOR_ARGS)
                                   ? IntermNodePatternMatcher::kScalarizedVecOrMatConstructor
                                   : 0;
  
      // Split multi declarations and remove calls to array length().
      // Note that SimplifyLoopConditions needs to be run before any other AST transformations
      // that may need to generate new statements from loop conditions or loop expressions.
      SimplifyLoopConditions(root,
                             IntermNodePatternMatcher::kMultiDeclaration |
                                 IntermNodePatternMatcher::kArrayLengthMethod | simplifyScalarized,
                             &getSymbolTable());
      if (!ValidateAST(root, &mDiagnostics, mValidateASTOptions))
      {
          return false;
      }
  
      // Note that separate declarations need to be run before other AST transformations that
      // generate new statements from expressions.
      SeparateDeclarations(root);
      mValidateASTOptions.validateMultiDeclarations = true;
      if (!ValidateAST(root, &mDiagnostics, mValidateASTOptions))
      {
          return false;
      }
  
      SplitSequenceOperator(root, IntermNodePatternMatcher::kArrayLengthMethod | simplifyScalarized,
                            &getSymbolTable());
      if (!ValidateAST(root, &mDiagnostics, mValidateASTOptions))
      {
          return false;
      }
  
      RemoveArrayLengthMethod(root);
      if (!ValidateAST(root, &mDiagnostics, mValidateASTOptions))
      {
          return false;
      }
  
      RemoveUnreferencedVariables(root, &mSymbolTable);
      if (!ValidateAST(root, &mDiagnostics, mValidateASTOptions))
      {
          return false;
      }
  
      // In case the last case inside a switch statement is a certain type of no-op, GLSL compilers in
      // drivers may not accept it. In this case we clean up the dead code from the end of switch
      // statements. This is also required because PruneNoOps or RemoveUnreferencedVariables may have
      // left switch statements that only contained an empty declaration inside the final case in an
      // invalid state. Relies on that PruneNoOps and RemoveUnreferencedVariables have already been
      // run.
      PruneEmptyCases(root);
      if (!ValidateAST(root, &mDiagnostics, mValidateASTOptions))
      {
          return false;
      }
  
      // Built-in function emulation needs to happen after validateLimitations pass.
      // TODO(jmadill): Remove global pool allocator.
      GetGlobalPoolAllocator()->lock();
      initBuiltInFunctionEmulator(&mBuiltInFunctionEmulator, compileOptions);
      GetGlobalPoolAllocator()->unlock();
      mBuiltInFunctionEmulator.markBuiltInFunctionsForEmulation(root);
  
      bool highPrecisionSupported = mShaderVersion > 100 || mShaderType != GL_FRAGMENT_SHADER ||
                                    mResources.FragmentPrecisionHigh == 1;
      if (compileOptions & SH_SCALARIZE_VEC_AND_MAT_CONSTRUCTOR_ARGS)
      {
          ScalarizeVecAndMatConstructorArgs(root, mShaderType, highPrecisionSupported, &mSymbolTable);
          if (!ValidateAST(root, &mDiagnostics, mValidateASTOptions))
          {
              return false;
          }
      }
  
      if (shouldCollectVariables(compileOptions))
      {
          ASSERT(!mVariablesCollected);
          CollectVariables(root, &mAttributes, &mOutputVariables, &mUniforms, &mInputVaryings,
                           &mOutputVaryings, &mUniformBlocks, &mShaderStorageBlocks, &mInBlocks,
                           mResources.HashFunction, &mSymbolTable, mShaderType, mExtensionBehavior);
          collectInterfaceBlocks();
          mVariablesCollected = true;
          if (compileOptions & SH_USE_UNUSED_STANDARD_SHARED_BLOCKS)
          {
              useAllMembersInUnusedStandardAndSharedBlocks(root);
          }
          if (compileOptions & SH_ENFORCE_PACKING_RESTRICTIONS)
          {
              int maxUniformVectors = GetMaxUniformVectorsForShaderType(mShaderType, mResources);
              // Returns true if, after applying the packing rules in the GLSL ES 1.00.17 spec
              // Appendix A, section 7, the shader does not use too many uniforms.
              if (!CheckVariablesInPackingLimits(maxUniformVectors, mUniforms))
              {
                  mDiagnostics.globalError("too many uniforms");
                  return false;
              }
          }
          if ((compileOptions & SH_INIT_OUTPUT_VARIABLES) && (mShaderType != GL_COMPUTE_SHADER))
          {
              initializeOutputVariables(root);
              if (!ValidateAST(root, &mDiagnostics, mValidateASTOptions))
              {
                  return false;
              }
          }
      }
  
      // Removing invariant declarations must be done after collecting variables.
      // Otherwise, built-in invariant declarations don't apply.
      if (RemoveInvariant(mShaderType, mShaderVersion, mOutputType, compileOptions))
      {
          RemoveInvariantDeclaration(root);
          if (!ValidateAST(root, &mDiagnostics, mValidateASTOptions))
          {
              return false;
          }
      }
  
      // gl_Position is always written in compatibility output mode.
      // It may have been already initialized among other output variables, in that case we don't
      // need to initialize it twice.
      if (mShaderType == GL_VERTEX_SHADER && !mGLPositionInitialized &&
          ((compileOptions & SH_INIT_GL_POSITION) || (mOutputType == SH_GLSL_COMPATIBILITY_OUTPUT)))
      {
          initializeGLPosition(root);
          mGLPositionInitialized = true;
          if (!ValidateAST(root, &mDiagnostics, mValidateASTOptions))
          {
              return false;
          }
      }
  
      // DeferGlobalInitializers needs to be run before other AST transformations that generate new
      // statements from expressions. But it's fine to run DeferGlobalInitializers after the above
      // SplitSequenceOperator and RemoveArrayLengthMethod since they only have an effect on the AST
      // on ESSL >= 3.00, and the initializers that need to be deferred can only exist in ESSL < 3.00.
      bool initializeLocalsAndGlobals =
          (compileOptions & SH_INITIALIZE_UNINITIALIZED_LOCALS) && !IsOutputHLSL(getOutputType());
      bool canUseLoopsToInitialize = !(compileOptions & SH_DONT_USE_LOOPS_TO_INITIALIZE_VARIABLES);
      DeferGlobalInitializers(root, initializeLocalsAndGlobals, canUseLoopsToInitialize,
                              highPrecisionSupported, &mSymbolTable);
      if (!ValidateAST(root, &mDiagnostics, mValidateASTOptions))
      {
          return false;
      }
  
      if (initializeLocalsAndGlobals)
      {
          // Initialize uninitialized local variables.
          // In some cases initializing can generate extra statements in the parent block, such as
          // when initializing nameless structs or initializing arrays in ESSL 1.00. In that case
          // we need to first simplify loop conditions. We've already separated declarations
          // earlier, which is also required. If we don't follow the Appendix A limitations, loop
          // init statements can declare arrays or nameless structs and have multiple
          // declarations.
  
          if (!shouldRunLoopAndIndexingValidation(compileOptions))
          {
              SimplifyLoopConditions(root,
                                     IntermNodePatternMatcher::kArrayDeclaration |
                                         IntermNodePatternMatcher::kNamelessStructDeclaration,
                                     &getSymbolTable());
              if (!ValidateAST(root, &mDiagnostics, mValidateASTOptions))
              {
                  return false;
              }
          }
  
          InitializeUninitializedLocals(root, getShaderVersion(), canUseLoopsToInitialize,
                                        highPrecisionSupported, &getSymbolTable());
          if (!ValidateAST(root, &mDiagnostics, mValidateASTOptions))
          {
              return false;
          }
      }
  
      if (getShaderType() == GL_VERTEX_SHADER && (compileOptions & SH_CLAMP_POINT_SIZE))
      {
          ClampPointSize(root, mResources.MaxPointSize, &getSymbolTable());
          if (!ValidateAST(root, &mDiagnostics, mValidateASTOptions))
          {
              return false;
          }
      }
  
      if (getShaderType() == GL_FRAGMENT_SHADER && (compileOptions & SH_CLAMP_FRAG_DEPTH))
      {
          ClampFragDepth(root, &getSymbolTable());
          if (!ValidateAST(root, &mDiagnostics, mValidateASTOptions))
          {
              return false;
          }
      }
  
      if (compileOptions & SH_REWRITE_REPEATED_ASSIGN_TO_SWIZZLED)
      {
          sh::RewriteRepeatedAssignToSwizzled(root);
          if (!ValidateAST(root, &mDiagnostics, mValidateASTOptions))
          {
              return false;
          }
      }
  
      if (compileOptions & SH_REWRITE_VECTOR_SCALAR_ARITHMETIC)
      {
          VectorizeVectorScalarArithmetic(root, &getSymbolTable());
          if (!ValidateAST(root, &mDiagnostics, mValidateASTOptions))
          {
              return false;
          }
      }
  
      return true;
  }
  
  bool TCompiler::compile(const char *const shaderStrings[],
                          size_t numStrings,
                          ShCompileOptions compileOptionsIn)
  {
  #if defined(ANGLE_ENABLE_FUZZER_CORPUS_OUTPUT)
      DumpFuzzerCase(shaderStrings, numStrings, mShaderType, mShaderSpec, mOutputType,
                     compileOptionsIn);
  #endif  // defined(ANGLE_ENABLE_FUZZER_CORPUS_OUTPUT)
  
      if (numStrings == 0)
          return true;
  
      ShCompileOptions compileOptions = compileOptionsIn;
  
      // Apply key workarounds.
      if (shouldFlattenPragmaStdglInvariantAll())
      {
          // This should be harmless to do in all cases, but for the moment, do it only conditionally.
          compileOptions |= SH_FLATTEN_PRAGMA_STDGL_INVARIANT_ALL;
      }
  
      TScopedPoolAllocator scopedAlloc(&allocator);
      TIntermBlock *root = compileTreeImpl(shaderStrings, numStrings, compileOptions);
  
      if (root)
      {
          if (compileOptions & SH_INTERMEDIATE_TREE)
              OutputTree(root, mInfoSink.info);
  
          if (compileOptions & SH_OBJECT_CODE)
          {
              PerformanceDiagnostics perfDiagnostics(&mDiagnostics);
              translate(root, compileOptions, &perfDiagnostics);
          }
  
          if (mShaderType == GL_VERTEX_SHADER &&
              IsExtensionEnabled(mExtensionBehavior, TExtension::ANGLE_multi_draw))
          {
              if ((compileOptions & SH_EMULATE_GL_DRAW_ID) != 0)
              {
                  for (auto &uniform : mUniforms)
                  {
                      if (uniform.name == "angle_DrawID" && uniform.mappedName == "angle_DrawID")
                      {
                          uniform.name = "gl_DrawID";
                          break;
                      }
                  }
              }
          }
  
          // The IntermNode tree doesn't need to be deleted here, since the
          // memory will be freed in a big chunk by the PoolAllocator.
          return true;
      }
      return false;
  }
  
  bool TCompiler::initBuiltInSymbolTable(const ShBuiltInResources &resources)
  {
      if (resources.MaxDrawBuffers < 1)
      {
          return false;
      }
      if (resources.EXT_blend_func_extended && resources.MaxDualSourceDrawBuffers < 1)
      {
          return false;
      }
  
      mSymbolTable.initializeBuiltIns(mShaderType, mShaderSpec, resources);
  
      return true;
  }
  
  void TCompiler::setResourceString()
  {
      std::ostringstream strstream = sh::InitializeStream<std::ostringstream>();
  
      // clang-format off
      strstream << ":MaxVertexAttribs:" << mResources.MaxVertexAttribs
          << ":MaxVertexUniformVectors:" << mResources.MaxVertexUniformVectors
          << ":MaxVaryingVectors:" << mResources.MaxVaryingVectors
          << ":MaxVertexTextureImageUnits:" << mResources.MaxVertexTextureImageUnits
          << ":MaxCombinedTextureImageUnits:" << mResources.MaxCombinedTextureImageUnits
          << ":MaxTextureImageUnits:" << mResources.MaxTextureImageUnits
          << ":MaxFragmentUniformVectors:" << mResources.MaxFragmentUniformVectors
          << ":MaxDrawBuffers:" << mResources.MaxDrawBuffers
          << ":OES_standard_derivatives:" << mResources.OES_standard_derivatives
          << ":OES_EGL_image_external:" << mResources.OES_EGL_image_external
          << ":OES_EGL_image_external_essl3:" << mResources.OES_EGL_image_external_essl3
          << ":NV_EGL_stream_consumer_external:" << mResources.NV_EGL_stream_consumer_external
          << ":ARB_texture_rectangle:" << mResources.ARB_texture_rectangle
          << ":EXT_draw_buffers:" << mResources.EXT_draw_buffers
          << ":FragmentPrecisionHigh:" << mResources.FragmentPrecisionHigh
          << ":MaxExpressionComplexity:" << mResources.MaxExpressionComplexity
          << ":MaxCallStackDepth:" << mResources.MaxCallStackDepth
          << ":MaxFunctionParameters:" << mResources.MaxFunctionParameters
          << ":EXT_blend_func_extended:" << mResources.EXT_blend_func_extended
          << ":EXT_frag_depth:" << mResources.EXT_frag_depth
          << ":EXT_shader_texture_lod:" << mResources.EXT_shader_texture_lod
          << ":EXT_shader_framebuffer_fetch:" << mResources.EXT_shader_framebuffer_fetch
          << ":NV_shader_framebuffer_fetch:" << mResources.NV_shader_framebuffer_fetch
          << ":ARM_shader_framebuffer_fetch:" << mResources.ARM_shader_framebuffer_fetch
          << ":OVR_multiview2:" << mResources.OVR_multiview2
          << ":OVR_multiview:" << mResources.OVR_multiview
          << ":EXT_YUV_target:" << mResources.EXT_YUV_target
          << ":EXT_geometry_shader:" << mResources.EXT_geometry_shader
          << ":MaxVertexOutputVectors:" << mResources.MaxVertexOutputVectors
          << ":MaxFragmentInputVectors:" << mResources.MaxFragmentInputVectors
          << ":MinProgramTexelOffset:" << mResources.MinProgramTexelOffset
          << ":MaxProgramTexelOffset:" << mResources.MaxProgramTexelOffset
          << ":MaxDualSourceDrawBuffers:" << mResources.MaxDualSourceDrawBuffers
          << ":MaxViewsOVR:" << mResources.MaxViewsOVR
          << ":NV_draw_buffers:" << mResources.NV_draw_buffers
          << ":WEBGL_debug_shader_precision:" << mResources.WEBGL_debug_shader_precision
          << ":ANGLE_multi_draw:" << mResources.ANGLE_multi_draw
          << ":MinProgramTextureGatherOffset:" << mResources.MinProgramTextureGatherOffset
          << ":MaxProgramTextureGatherOffset:" << mResources.MaxProgramTextureGatherOffset
          << ":MaxImageUnits:" << mResources.MaxImageUnits
          << ":MaxVertexImageUniforms:" << mResources.MaxVertexImageUniforms
          << ":MaxFragmentImageUniforms:" << mResources.MaxFragmentImageUniforms
          << ":MaxComputeImageUniforms:" << mResources.MaxComputeImageUniforms
          << ":MaxCombinedImageUniforms:" << mResources.MaxCombinedImageUniforms
          << ":MaxCombinedShaderOutputResources:" << mResources.MaxCombinedShaderOutputResources
          << ":MaxComputeWorkGroupCountX:" << mResources.MaxComputeWorkGroupCount[0]
          << ":MaxComputeWorkGroupCountY:" << mResources.MaxComputeWorkGroupCount[1]
          << ":MaxComputeWorkGroupCountZ:" << mResources.MaxComputeWorkGroupCount[2]
          << ":MaxComputeWorkGroupSizeX:" << mResources.MaxComputeWorkGroupSize[0]
          << ":MaxComputeWorkGroupSizeY:" << mResources.MaxComputeWorkGroupSize[1]
          << ":MaxComputeWorkGroupSizeZ:" << mResources.MaxComputeWorkGroupSize[2]
          << ":MaxComputeUniformComponents:" << mResources.MaxComputeUniformComponents
          << ":MaxComputeTextureImageUnits:" << mResources.MaxComputeTextureImageUnits
          << ":MaxComputeAtomicCounters:" << mResources.MaxComputeAtomicCounters
          << ":MaxComputeAtomicCounterBuffers:" << mResources.MaxComputeAtomicCounterBuffers
          << ":MaxVertexAtomicCounters:" << mResources.MaxVertexAtomicCounters
          << ":MaxFragmentAtomicCounters:" << mResources.MaxFragmentAtomicCounters
          << ":MaxCombinedAtomicCounters:" << mResources.MaxCombinedAtomicCounters
          << ":MaxAtomicCounterBindings:" << mResources.MaxAtomicCounterBindings
          << ":MaxVertexAtomicCounterBuffers:" << mResources.MaxVertexAtomicCounterBuffers
          << ":MaxFragmentAtomicCounterBuffers:" << mResources.MaxFragmentAtomicCounterBuffers
          << ":MaxCombinedAtomicCounterBuffers:" << mResources.MaxCombinedAtomicCounterBuffers
          << ":MaxAtomicCounterBufferSize:" << mResources.MaxAtomicCounterBufferSize
          << ":MaxGeometryUniformComponents:" << mResources.MaxGeometryUniformComponents
          << ":MaxGeometryUniformBlocks:" << mResources.MaxGeometryUniformBlocks
          << ":MaxGeometryInputComponents:" << mResources.MaxGeometryInputComponents
          << ":MaxGeometryOutputComponents:" << mResources.MaxGeometryOutputComponents
          << ":MaxGeometryOutputVertices:" << mResources.MaxGeometryOutputVertices
          << ":MaxGeometryTotalOutputComponents:" << mResources.MaxGeometryTotalOutputComponents
          << ":MaxGeometryTextureImageUnits:" << mResources.MaxGeometryTextureImageUnits
          << ":MaxGeometryAtomicCounterBuffers:" << mResources.MaxGeometryAtomicCounterBuffers
          << ":MaxGeometryAtomicCounters:" << mResources.MaxGeometryAtomicCounters
          << ":MaxGeometryShaderStorageBlocks:" << mResources.MaxGeometryShaderStorageBlocks
          << ":MaxGeometryShaderInvocations:" << mResources.MaxGeometryShaderInvocations
          << ":MaxGeometryImageUniforms:" << mResources.MaxGeometryImageUniforms;
      // clang-format on
  
      mBuiltInResourcesString = strstream.str();
  }
  
  void TCompiler::collectInterfaceBlocks()
  {
      ASSERT(mInterfaceBlocks.empty());
      mInterfaceBlocks.reserve(mUniformBlocks.size() + mShaderStorageBlocks.size() +
                               mInBlocks.size());
      mInterfaceBlocks.insert(mInterfaceBlocks.end(), mUniformBlocks.begin(), mUniformBlocks.end());
      mInterfaceBlocks.insert(mInterfaceBlocks.end(), mShaderStorageBlocks.begin(),
                              mShaderStorageBlocks.end());
      mInterfaceBlocks.insert(mInterfaceBlocks.end(), mInBlocks.begin(), mInBlocks.end());
  }
  
  void TCompiler::clearResults()
  {
      mArrayBoundsClamper.Cleanup();
      mInfoSink.info.erase();
      mInfoSink.obj.erase();
      mInfoSink.debug.erase();
      mDiagnostics.resetErrorCount();
  
      mAttributes.clear();
      mOutputVariables.clear();
      mUniforms.clear();
      mInputVaryings.clear();
      mOutputVaryings.clear();
      mInterfaceBlocks.clear();
      mUniformBlocks.clear();
      mShaderStorageBlocks.clear();
      mInBlocks.clear();
      mVariablesCollected    = false;
      mGLPositionInitialized = false;
  
      mNumViews = -1;
  
      mGeometryShaderInputPrimitiveType  = EptUndefined;
      mGeometryShaderOutputPrimitiveType = EptUndefined;
      mGeometryShaderInvocations         = 0;
      mGeometryShaderMaxVertices         = -1;
  
      mBuiltInFunctionEmulator.cleanup();
  
      mNameMap.clear();
  
      mSourcePath = nullptr;
  
      mSymbolTable.clearCompilationResults();
  }
  
  bool TCompiler::initCallDag(TIntermNode *root)
  {
      mCallDag.clear();
  
      switch (mCallDag.init(root, &mDiagnostics))
      {
          case CallDAG::INITDAG_SUCCESS:
              return true;
          case CallDAG::INITDAG_RECURSION:
          case CallDAG::INITDAG_UNDEFINED:
              // Error message has already been written out.
              ASSERT(mDiagnostics.numErrors() > 0);
              return false;
      }
  
      UNREACHABLE();
      return true;
  }
  
  bool TCompiler::checkCallDepth()
  {
      std::vector<int> depths(mCallDag.size());
  
      for (size_t i = 0; i < mCallDag.size(); i++)
      {
          int depth                     = 0;
          const CallDAG::Record &record = mCallDag.getRecordFromIndex(i);
  
          for (const int &calleeIndex : record.callees)
          {
              depth = std::max(depth, depths[calleeIndex] + 1);
          }
  
          depths[i] = depth;
  
          if (depth >= mResources.MaxCallStackDepth)
          {
              // Trace back the function chain to have a meaningful info log.
              std::stringstream errorStream = sh::InitializeStream<std::stringstream>();
              errorStream << "Call stack too deep (larger than " << mResources.MaxCallStackDepth
                          << ") with the following call chain: "
                          << record.node->getFunction()->name();
  
              int currentFunction = static_cast<int>(i);
              int currentDepth    = depth;
  
              while (currentFunction != -1)
              {
                  errorStream
                      << " -> "
                      << mCallDag.getRecordFromIndex(currentFunction).node->getFunction()->name();
  
                  int nextFunction = -1;
                  for (const int &calleeIndex : mCallDag.getRecordFromIndex(currentFunction).callees)
                  {
                      if (depths[calleeIndex] == currentDepth - 1)
                      {
                          currentDepth--;
                          nextFunction = calleeIndex;
                      }
                  }
  
                  currentFunction = nextFunction;
              }
  
              std::string errorStr = errorStream.str();
              mDiagnostics.globalError(errorStr.c_str());
  
              return false;
          }
      }
  
      return true;
  }
  
  bool TCompiler::tagUsedFunctions()
  {
      // Search from main, starting from the end of the DAG as it usually is the root.
      for (size_t i = mCallDag.size(); i-- > 0;)
      {
          if (mCallDag.getRecordFromIndex(i).node->getFunction()->isMain())
          {
              internalTagUsedFunction(i);
              return true;
          }
      }
  
      mDiagnostics.globalError("Missing main()");
      return false;
  }
  
  void TCompiler::internalTagUsedFunction(size_t index)
  {
      if (mFunctionMetadata[index].used)
      {
          return;
      }
  
      mFunctionMetadata[index].used = true;
  
      for (int calleeIndex : mCallDag.getRecordFromIndex(index).callees)
      {
          internalTagUsedFunction(calleeIndex);
      }
  }
  
  // A predicate for the stl that returns if a top-level node is unused
  class TCompiler::UnusedPredicate
  {
    public:
      UnusedPredicate(const CallDAG *callDag, const std::vector<FunctionMetadata> *metadatas)
          : mCallDag(callDag), mMetadatas(metadatas)
      {}
  
      bool operator()(TIntermNode *node)
      {
          const TIntermFunctionPrototype *asFunctionPrototype   = node->getAsFunctionPrototypeNode();
          const TIntermFunctionDefinition *asFunctionDefinition = node->getAsFunctionDefinition();
  
          const TFunction *func = nullptr;
  
          if (asFunctionDefinition)
          {
              func = asFunctionDefinition->getFunction();
          }
          else if (asFunctionPrototype)
          {
              func = asFunctionPrototype->getFunction();
          }
          if (func == nullptr)
          {
              return false;
          }
  
          size_t callDagIndex = mCallDag->findIndex(func->uniqueId());
          if (callDagIndex == CallDAG::InvalidIndex)
          {
              // This happens only for unimplemented prototypes which are thus unused
              ASSERT(asFunctionPrototype);
              return true;
          }
  
          ASSERT(callDagIndex < mMetadatas->size());
          return !(*mMetadatas)[callDagIndex].used;
      }
  
    private:
      const CallDAG *mCallDag;
      const std::vector<FunctionMetadata> *mMetadatas;
  };
  
  void TCompiler::pruneUnusedFunctions(TIntermBlock *root)
  {
      UnusedPredicate isUnused(&mCallDag, &mFunctionMetadata);
      TIntermSequence *sequence = root->getSequence();
  
      if (!sequence->empty())
      {
          sequence->erase(std::remove_if(sequence->begin(), sequence->end(), isUnused),
                          sequence->end());
      }
  }
  
  bool TCompiler::limitExpressionComplexity(TIntermBlock *root)
  {
      if (!IsASTDepthBelowLimit(root, mResources.MaxExpressionComplexity))
      {
          mDiagnostics.globalError("Expression too complex.");
          return false;
      }
  
      if (!ValidateMaxParameters(root, mResources.MaxFunctionParameters))
      {
          mDiagnostics.globalError("Function has too many parameters.");
          return false;
      }
  
      return true;
  }
  
  bool TCompiler::shouldCollectVariables(ShCompileOptions compileOptions)
  {
      return (compileOptions & SH_VARIABLES) != 0;
  }
  
  bool TCompiler::wereVariablesCollected() const
  {
      return mVariablesCollected;
  }
  
  void TCompiler::initializeGLPosition(TIntermBlock *root)
  {
      InitVariableList list;
      sh::ShaderVariable var(GL_FLOAT_VEC4);
      var.name = "gl_Position";
      list.push_back(var);
      InitializeVariables(root, list, &mSymbolTable, mShaderVersion, mExtensionBehavior, false,
                          false);
  }
  
  void TCompiler::useAllMembersInUnusedStandardAndSharedBlocks(TIntermBlock *root)
  {
      sh::InterfaceBlockList list;
  
      for (const sh::InterfaceBlock &block : mUniformBlocks)
      {
          if (!block.staticUse &&
              (block.layout == sh::BLOCKLAYOUT_STD140 || block.layout == sh::BLOCKLAYOUT_SHARED))
          {
              list.push_back(block);
          }
      }
  
      sh::UseInterfaceBlockFields(root, list, mSymbolTable);
  }
  
  void TCompiler::initializeOutputVariables(TIntermBlock *root)
  {
      InitVariableList list;
      if (mShaderType == GL_VERTEX_SHADER || mShaderType == GL_GEOMETRY_SHADER_EXT)
      {
          for (const sh::Varying &var : mOutputVaryings)
          {
              list.push_back(var);
              if (var.name == "gl_Position")
              {
                  ASSERT(!mGLPositionInitialized);
                  mGLPositionInitialized = true;
              }
          }
      }
      else
      {
          ASSERT(mShaderType == GL_FRAGMENT_SHADER);
          for (const sh::OutputVariable &var : mOutputVariables)
          {
              list.push_back(var);
          }
      }
      InitializeVariables(root, list, &mSymbolTable, mShaderVersion, mExtensionBehavior, false,
                          false);
  }
  
  const TExtensionBehavior &TCompiler::getExtensionBehavior() const
  {
      return mExtensionBehavior;
  }
  
  const char *TCompiler::getSourcePath() const
  {
      return mSourcePath;
  }
  
  const ShBuiltInResources &TCompiler::getResources() const
  {
      return mResources;
  }
  
  const ArrayBoundsClamper &TCompiler::getArrayBoundsClamper() const
  {
      return mArrayBoundsClamper;
  }
  
  ShArrayIndexClampingStrategy TCompiler::getArrayIndexClampingStrategy() const
  {
      return mResources.ArrayIndexClampingStrategy;
  }
  
  const BuiltInFunctionEmulator &TCompiler::getBuiltInFunctionEmulator() const
  {
      return mBuiltInFunctionEmulator;
  }
  
  void TCompiler::writePragma(ShCompileOptions compileOptions)
  {
      if (!(compileOptions & SH_FLATTEN_PRAGMA_STDGL_INVARIANT_ALL))
      {
          TInfoSinkBase &sink = mInfoSink.obj;
          if (mPragma.stdgl.invariantAll)
              sink << "#pragma STDGL invariant(all)\n";
      }
  }
  
  bool TCompiler::isVaryingDefined(const char *varyingName)
  {
      ASSERT(mVariablesCollected);
      for (size_t ii = 0; ii < mInputVaryings.size(); ++ii)
      {
          if (mInputVaryings[ii].name == varyingName)
          {
              return true;
          }
      }
      for (size_t ii = 0; ii < mOutputVaryings.size(); ++ii)
      {
          if (mOutputVaryings[ii].name == varyingName)
          {
              return true;
          }
      }
  
      return false;
  }
  
  void EmitMultiviewGLSL(const TCompiler &compiler,
                         const ShCompileOptions &compileOptions,
                         const TBehavior behavior,
                         TInfoSinkBase &sink)
  {
      ASSERT(behavior != EBhUndefined);
      if (behavior == EBhDisable)
          return;
  
      const bool isVertexShader = (compiler.getShaderType() == GL_VERTEX_SHADER);
      if (compileOptions & SH_INITIALIZE_BUILTINS_FOR_INSTANCED_MULTIVIEW)
      {
          // Emit ARB_shader_viewport_layer_array/NV_viewport_array2 in a vertex shader if the
          // SH_SELECT_VIEW_IN_NV_GLSL_VERTEX_SHADER option is set and the
          // OVR_multiview(2) extension is requested.
          if (isVertexShader && (compileOptions & SH_SELECT_VIEW_IN_NV_GLSL_VERTEX_SHADER))
          {
              sink << "#if defined(GL_ARB_shader_viewport_layer_array)\n"
                   << "#extension GL_ARB_shader_viewport_layer_array : require\n"
                   << "#elif defined(GL_NV_viewport_array2)\n"
                   << "#extension GL_NV_viewport_array2 : require\n"
                   << "#endif\n";
          }
      }
      else
      {
          sink << "#extension GL_OVR_multiview2 : " << GetBehaviorString(behavior) << "\n";
  
          const auto &numViews = compiler.getNumViews();
          if (isVertexShader && numViews != -1)
          {
              sink << "layout(num_views=" << numViews << ") in;\n";
          }
      }
  }
  
  }  // namespace sh
  

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