glslang/MachineIndependent/ParseHelper.cpp

//
// Copyright (C) 2002-2005  3Dlabs Inc. Ltd.
// Copyright (C) 2012-2015 LunarG, Inc.
// Copyright (C) 2015-2018 Google, Inc.
// Copyright (C) 2017 ARM Limited.
//
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
//
//    Redistributions of source code must retain the above copyright
//    notice, this list of conditions and the following disclaimer.
//
//    Redistributions in binary form must reproduce the above
//    copyright notice, this list of conditions and the following
//    disclaimer in the documentation and/or other materials provided
//    with the distribution.
//
//    Neither the name of 3Dlabs Inc. Ltd. nor the names of its
//    contributors may be used to endorse or promote products derived
//    from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
// FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
// COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
// BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
// LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
// ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
//

#include "ParseHelper.h"
#include "Scan.h"

#include "../OSDependent/osinclude.h"
#include <algorithm>

#include "preprocessor/PpContext.h"

extern int yyparse(glslang::TParseContext*);

namespace glslang {

TParseContext::TParseContext(TSymbolTable& symbolTable, TIntermediate& interm, bool parsingBuiltins,
                             int version, EProfile profile, const SpvVersion& spvVersion, EShLanguage language,
                             TInfoSink& infoSink, bool forwardCompatible, EShMessages messages,
                             const TString* entryPoint) :
            TParseContextBase(symbolTable, interm, parsingBuiltins, version, profile, spvVersion, language,
                              infoSink, forwardCompatible, messages, entryPoint),
            inMain(false),
            blockName(nullptr),
            limits(resources.limits)
#ifndef GLSLANG_WEB
            ,
            atomicUintOffsets(nullptr), anyIndexLimits(false)
#endif
{
    // decide whether precision qualifiers should be ignored or respected
    if (isEsProfile() || spvVersion.vulkan > 0) {
        precisionManager.respectPrecisionQualifiers();
        if (! parsingBuiltins && language == EShLangFragment && !isEsProfile() && spvVersion.vulkan > 0)
            precisionManager.warnAboutDefaults();
    }

    setPrecisionDefaults();

    globalUniformDefaults.clear();
    globalUniformDefaults.layoutMatrix = ElmColumnMajor;
    globalUniformDefaults.layoutPacking = spvVersion.spv != 0 ? ElpStd140 : ElpShared;

    globalBufferDefaults.clear();
    globalBufferDefaults.layoutMatrix = ElmColumnMajor;
    globalBufferDefaults.layoutPacking = spvVersion.spv != 0 ? ElpStd430 : ElpShared;

    // use storage buffer on SPIR-V 1.3 and up
    if (spvVersion.spv >= EShTargetSpv_1_3)
        intermediate.setUseStorageBuffer();

    globalInputDefaults.clear();
    globalOutputDefaults.clear();

#ifndef GLSLANG_WEB
    // "Shaders in the transform
    // feedback capturing mode have an initial global default of
    //     layout(xfb_buffer = 0) out;"
    if (language == EShLangVertex ||
        language == EShLangTessControl ||
        language == EShLangTessEvaluation ||
        language == EShLangGeometry)
        globalOutputDefaults.layoutXfbBuffer = 0;

    if (language == EShLangGeometry)
        globalOutputDefaults.layoutStream = 0;
#endif

    if (entryPoint != nullptr && entryPoint->size() > 0 && *entryPoint != "main")
        infoSink.info.message(EPrefixError, "Source entry point must be \"main\"");
}

TParseContext::~TParseContext()
{
#ifndef GLSLANG_WEB
    delete [] atomicUintOffsets;
#endif
}

// Set up all default precisions as needed by the current environment.
// Intended just as a TParseContext constructor helper.
void TParseContext::setPrecisionDefaults()
{
    // Set all precision defaults to EpqNone, which is correct for all types
    // when not obeying precision qualifiers, and correct for types that don't
    // have defaults (thus getting an error on use) when obeying precision
    // qualifiers.

    for (int type = 0; type < EbtNumTypes; ++type)
        defaultPrecision[type] = EpqNone;

    for (int type = 0; type < maxSamplerIndex; ++type)
        defaultSamplerPrecision[type] = EpqNone;

    // replace with real precision defaults for those that have them
    if (obeyPrecisionQualifiers()) {
        if (isEsProfile()) {
            // Most don't have defaults, a few default to lowp.
            TSampler sampler;
            sampler.set(EbtFloat, Esd2D);
            defaultSamplerPrecision[computeSamplerTypeIndex(sampler)] = EpqLow;
            sampler.set(EbtFloat, EsdCube);
            defaultSamplerPrecision[computeSamplerTypeIndex(sampler)] = EpqLow;
            sampler.set(EbtFloat, Esd2D);
            sampler.setExternal(true);
            defaultSamplerPrecision[computeSamplerTypeIndex(sampler)] = EpqLow;
        }

        // If we are parsing built-in computational variables/functions, it is meaningful to record
        // whether the built-in has no precision qualifier, as that ambiguity
        // is used to resolve the precision from the supplied arguments/operands instead.
        // So, we don't actually want to replace EpqNone with a default precision for built-ins.
        if (! parsingBuiltins) {
            if (isEsProfile() && language == EShLangFragment) {
                defaultPrecision[EbtInt] = EpqMedium;
                defaultPrecision[EbtUint] = EpqMedium;
            } else {
                defaultPrecision[EbtInt] = EpqHigh;
                defaultPrecision[EbtUint] = EpqHigh;
                defaultPrecision[EbtFloat] = EpqHigh;
            }

            if (!isEsProfile()) {
                // Non-ES profile
                // All sampler precisions default to highp.
                for (int type = 0; type < maxSamplerIndex; ++type)
                    defaultSamplerPrecision[type] = EpqHigh;
            }
        }

        defaultPrecision[EbtSampler] = EpqLow;
        defaultPrecision[EbtAtomicUint] = EpqHigh;
    }
}

void TParseContext::setLimits(const TBuiltInResource& r)
{
    resources = r;
    intermediate.setLimits(r);

#ifndef GLSLANG_WEB
    anyIndexLimits = ! limits.generalAttributeMatrixVectorIndexing ||
                     ! limits.generalConstantMatrixVectorIndexing ||
                     ! limits.generalSamplerIndexing ||
                     ! limits.generalUniformIndexing ||
                     ! limits.generalVariableIndexing ||
                     ! limits.generalVaryingIndexing;


    // "Each binding point tracks its own current default offset for
    // inheritance of subsequent variables using the same binding. The initial state of compilation is that all
    // binding points have an offset of 0."
    atomicUintOffsets = new int[resources.maxAtomicCounterBindings];
    for (int b = 0; b < resources.maxAtomicCounterBindings; ++b)
        atomicUintOffsets[b] = 0;
#endif
}

//
// Parse an array of strings using yyparse, going through the
// preprocessor to tokenize the shader strings, then through
// the GLSL scanner.
//
// Returns true for successful acceptance of the shader, false if any errors.
//
bool TParseContext::parseShaderStrings(TPpContext& ppContext, TInputScanner& input, bool versionWillBeError)
{
    currentScanner = &input;
    ppContext.setInput(input, versionWillBeError);
    yyparse(this);

    finish();

    return numErrors == 0;
}

// This is called from bison when it has a parse (syntax) error
// Note though that to stop cascading errors, we set EOF, which
// will usually cause a syntax error, so be more accurate that
// compilation is terminating.
void TParseContext::parserError(const char* s)
{
    if (! getScanner()->atEndOfInput() || numErrors == 0)
        error(getCurrentLoc(), "", "", s, "");
    else
        error(getCurrentLoc(), "compilation terminated", "", "");
}

void TParseContext::handlePragma(const TSourceLoc& loc, const TVector<TString>& tokens)
{
#ifndef GLSLANG_WEB
    if (pragmaCallback)
        pragmaCallback(loc.line, tokens);

    if (tokens.size() == 0)
        return;

    if (tokens[0].compare("optimize") == 0) {
        if (tokens.size() != 4) {
            error(loc, "optimize pragma syntax is incorrect", "#pragma", "");
            return;
        }

        if (tokens[1].compare("(") != 0) {
            error(loc, "\"(\" expected after 'optimize' keyword", "#pragma", "");
            return;
        }

        if (tokens[2].compare("on") == 0)
            contextPragma.optimize = true;
        else if (tokens[2].compare("off") == 0)
            contextPragma.optimize = false;
        else {
            error(loc, "\"on\" or \"off\" expected after '(' for 'optimize' pragma", "#pragma", "");
            return;
        }

        if (tokens[3].compare(")") != 0) {
            error(loc, "\")\" expected to end 'optimize' pragma", "#pragma", "");
            return;
        }
    } else if (tokens[0].compare("debug") == 0) {
        if (tokens.size() != 4) {
            error(loc, "debug pragma syntax is incorrect", "#pragma", "");
            return;
        }

        if (tokens[1].compare("(") != 0) {
            error(loc, "\"(\" expected after 'debug' keyword", "#pragma", "");
            return;
        }

        if (tokens[2].compare("on") == 0)
            contextPragma.debug = true;
        else if (tokens[2].compare("off") == 0)
            contextPragma.debug = false;
        else {
            error(loc, "\"on\" or \"off\" expected after '(' for 'debug' pragma", "#pragma", "");
            return;
        }

        if (tokens[3].compare(")") != 0) {
            error(loc, "\")\" expected to end 'debug' pragma", "#pragma", "");
            return;
        }
    } else if (spvVersion.spv > 0 && tokens[0].compare("use_storage_buffer") == 0) {
        if (tokens.size() != 1)
            error(loc, "extra tokens", "#pragma", "");
        intermediate.setUseStorageBuffer();
    } else if (spvVersion.spv > 0 && tokens[0].compare("use_vulkan_memory_model") == 0) {
        if (tokens.size() != 1)
            error(loc, "extra tokens", "#pragma", "");
        intermediate.setUseVulkanMemoryModel();
    } else if (spvVersion.spv > 0 && tokens[0].compare("use_variable_pointers") == 0) {
        if (tokens.size() != 1)
            error(loc, "extra tokens", "#pragma", "");
        if (spvVersion.spv < glslang::EShTargetSpv_1_3)
            error(loc, "requires SPIR-V 1.3", "#pragma use_variable_pointers", "");
        intermediate.setUseVariablePointers();
    } else if (tokens[0].compare("once") == 0) {
        warn(loc, "not implemented", "#pragma once", "");
    } else if (tokens[0].compare("glslang_binary_double_output") == 0)
        intermediate.setBinaryDoubleOutput();
#endif
}

//
// Handle seeing a variable identifier in the grammar.
//
TIntermTyped* TParseContext::handleVariable(const TSourceLoc& loc, TSymbol* symbol, const TString* string)
{
    TIntermTyped* node = nullptr;

    // Error check for requiring specific extensions present.
    if (symbol && symbol->getNumExtensions())
        requireExtensions(loc, symbol->getNumExtensions(), symbol->getExtensions(), symbol->getName().c_str());

#ifndef GLSLANG_WEB
    if (symbol && symbol->isReadOnly()) {
        // All shared things containing an unsized array must be copied up
        // on first use, so that all future references will share its array structure,
        // so that editing the implicit size will effect all nodes consuming it,
        // and so that editing the implicit size won't change the shared one.
        //
        // If this is a variable or a block, check it and all it contains, but if this
        // is a member of an anonymous block, check the whole block, as the whole block
        // will need to be copied up if it contains an unsized array.
        //
        // This check is being done before the block-name check further down, so guard
        // for that too.
        if (!symbol->getType().isUnusableName()) {
            if (symbol->getType().containsUnsizedArray() ||
                (symbol->getAsAnonMember() &&
                 symbol->getAsAnonMember()->getAnonContainer().getType().containsUnsizedArray()))
                makeEditable(symbol);
        }
    }
#endif

    const TVariable* variable;
    const TAnonMember* anon = symbol ? symbol->getAsAnonMember() : nullptr;
    if (anon) {
        // It was a member of an anonymous container.

        // Create a subtree for its dereference.
        variable = anon->getAnonContainer().getAsVariable();
        TIntermTyped* container = intermediate.addSymbol(*variable, loc);
        TIntermTyped* constNode = intermediate.addConstantUnion(anon->getMemberNumber(), loc);
        node = intermediate.addIndex(EOpIndexDirectStruct, container, constNode, loc);

        node->setType(*(*variable->getType().getStruct())[anon->getMemberNumber()].type);
        if (node->getType().hiddenMember())
            error(loc, "member of nameless block was not redeclared", string->c_str(), "");
    } else {
        // Not a member of an anonymous container.

        // The symbol table search was done in the lexical phase.
        // See if it was a variable.
        variable = symbol ? symbol->getAsVariable() : nullptr;
        if (variable) {
            if (variable->getType().isUnusableName()) {
                error(loc, "cannot be used (maybe an instance name is needed)", string->c_str(), "");
                variable = nullptr;
            }
        } else {
            if (symbol)
                error(loc, "variable name expected", string->c_str(), "");
        }

        // Recovery, if it wasn't found or was not a variable.
        if (! variable)
            variable = new TVariable(string, TType(EbtVoid));

        if (variable->getType().getQualifier().isFrontEndConstant())
            node = intermediate.addConstantUnion(variable->getConstArray(), variable->getType(), loc);
        else
            node = intermediate.addSymbol(*variable, loc);
    }

    if (variable->getType().getQualifier().isIo())
        intermediate.addIoAccessed(*string);

    if (variable->getType().isReference() &&
        variable->getType().getQualifier().bufferReferenceNeedsVulkanMemoryModel()) {
        intermediate.setUseVulkanMemoryModel();
    }

    return node;
}

//
// Handle seeing a base[index] dereference in the grammar.
//
TIntermTyped* TParseContext::handleBracketDereference(const TSourceLoc& loc, TIntermTyped* base, TIntermTyped* index)
{
    int indexValue = 0;
    if (index->getQualifier().isFrontEndConstant())
        indexValue = index->getAsConstantUnion()->getConstArray()[0].getIConst();

    // basic type checks...
    variableCheck(base);

    if (! base->isArray() && ! base->isMatrix() && ! base->isVector() && ! base->getType().isCoopMat() &&
        ! base->isReference()) {
        if (base->getAsSymbolNode())
            error(loc, " left of '[' is not of type array, matrix, or vector ", base->getAsSymbolNode()->getName().c_str(), "");
        else
            error(loc, " left of '[' is not of type array, matrix, or vector ", "expression", "");

        // Insert dummy error-recovery result
        return intermediate.addConstantUnion(0.0, EbtFloat, loc);
    }

    if (!base->isArray() && base->isVector()) {
        if (base->getType().contains16BitFloat())
            requireFloat16Arithmetic(loc, "[", "does not operate on types containing float16");
        if (base->getType().contains16BitInt())
            requireInt16Arithmetic(loc, "[", "does not operate on types containing (u)int16");
        if (base->getType().contains8BitInt())
            requireInt8Arithmetic(loc, "[", "does not operate on types containing (u)int8");
    }

    // check for constant folding
    if (base->getType().getQualifier().isFrontEndConstant() && index->getQualifier().isFrontEndConstant()) {
        // both base and index are front-end constants
        checkIndex(loc, base->getType(), indexValue);
        return intermediate.foldDereference(base, indexValue, loc);
    }

    // at least one of base and index is not a front-end constant variable...
    TIntermTyped* result = nullptr;

#ifndef GLSLANG_WEB
    if (base->isReference() && ! base->isArray()) {
        requireExtensions(loc, 1, &E_GL_EXT_buffer_reference2, "buffer reference indexing");
        result = intermediate.addBinaryMath(EOpAdd, base, index, loc);
        result->setType(base->getType());
        return result;
    }
    if (base->getAsSymbolNode() && isIoResizeArray(base->getType()))
        handleIoResizeArrayAccess(loc, base);
#endif

    if (index->getQualifier().isFrontEndConstant())
        checkIndex(loc, base->getType(), indexValue);

    if (index->getQualifier().isFrontEndConstant()) {
#ifndef GLSLANG_WEB
        if (base->getType().isUnsizedArray()) {
            base->getWritableType().updateImplicitArraySize(indexValue + 1);
            // For 2D per-view builtin arrays, update the inner dimension size in parent type
            if (base->getQualifier().isPerView() && base->getQualifier().builtIn != EbvNone) {
                TIntermBinary* binaryNode = base->getAsBinaryNode();
                if (binaryNode) {
                    TType& leftType = binaryNode->getLeft()->getWritableType();
                    TArraySizes& arraySizes = *leftType.getArraySizes();
                    assert(arraySizes.getNumDims() == 2);
                    arraySizes.setDimSize(1, std::max(arraySizes.getDimSize(1), indexValue + 1));
                }
            }
        } else
#endif
            checkIndex(loc, base->getType(), indexValue);
        result = intermediate.addIndex(EOpIndexDirect, base, index, loc);
    } else {
#ifndef GLSLANG_WEB
        if (base->getType().isUnsizedArray()) {
            // we have a variable index into an unsized array, which is okay,
            // depending on the situation
            if (base->getAsSymbolNode() && isIoResizeArray(base->getType()))
                error(loc, "", "[", "array must be sized by a redeclaration or layout qualifier before being indexed with a variable");
            else {
                // it is okay for a run-time sized array
                checkRuntimeSizable(loc, *base);
            }
            base->getWritableType().setArrayVariablyIndexed();
        }
#endif
        if (base->getBasicType() == EbtBlock) {
            if (base->getQualifier().storage == EvqBuffer)
                requireProfile(base->getLoc(), ~EEsProfile, "variable indexing buffer block array");
            else if (base->getQualifier().storage == EvqUniform)
                profileRequires(base->getLoc(), EEsProfile, 320, Num_AEP_gpu_shader5, AEP_gpu_shader5,
                                "variable indexing uniform block array");
            else {
                // input/output blocks either don't exist or can't be variably indexed
            }
        } else if (language == EShLangFragment && base->getQualifier().isPipeOutput())
            requireProfile(base->getLoc(), ~EEsProfile, "variable indexing fragment shader output array");
        else if (base->getBasicType() == EbtSampler && version >= 130) {
            const char* explanation = "variable indexing sampler array";
            requireProfile(base->getLoc(), EEsProfile | ECoreProfile | ECompatibilityProfile, explanation);
            profileRequires(base->getLoc(), EEsProfile, 320, Num_AEP_gpu_shader5, AEP_gpu_shader5, explanation);
            profileRequires(base->getLoc(), ECoreProfile | ECompatibilityProfile, 400, nullptr, explanation);
        }

        result = intermediate.addIndex(EOpIndexIndirect, base, index, loc);
    }

    // Insert valid dereferenced result type
    TType newType(base->getType(), 0);
    if (base->getType().getQualifier().isConstant() && index->getQualifier().isConstant()) {
        newType.getQualifier().storage = EvqConst;
        // If base or index is a specialization constant, the result should also be a specialization constant.
        if (base->getType().getQualifier().isSpecConstant() || index->getQualifier().isSpecConstant()) {
            newType.getQualifier().makeSpecConstant();
        }
    } else {
        newType.getQualifier().storage = EvqTemporary;
        newType.getQualifier().specConstant = false;
    }
    result->setType(newType);

#ifndef GLSLANG_WEB
    inheritMemoryQualifiers(base->getQualifier(), result->getWritableType().getQualifier());

    // Propagate nonuniform
    if (base->getQualifier().isNonUniform() || index->getQualifier().isNonUniform())
        result->getWritableType().getQualifier().nonUniform = true;

    if (anyIndexLimits)
        handleIndexLimits(loc, base, index);
#endif

    return result;
}

#ifndef GLSLANG_WEB

// for ES 2.0 (version 100) limitations for almost all index operations except vertex-shader uniforms
void TParseContext::handleIndexLimits(const TSourceLoc& /*loc*/, TIntermTyped* base, TIntermTyped* index)
{
    if ((! limits.generalSamplerIndexing && base->getBasicType() == EbtSampler) ||
        (! limits.generalUniformIndexing && base->getQualifier().isUniformOrBuffer() && language != EShLangVertex) ||
        (! limits.generalAttributeMatrixVectorIndexing && base->getQualifier().isPipeInput() && language == EShLangVertex && (base->getType().isMatrix() || base->getType().isVector())) ||
        (! limits.generalConstantMatrixVectorIndexing && base->getAsConstantUnion()) ||
        (! limits.generalVariableIndexing && ! base->getType().getQualifier().isUniformOrBuffer() &&
                                             ! base->getType().getQualifier().isPipeInput() &&
                                             ! base->getType().getQualifier().isPipeOutput() &&
                                             ! base->getType().getQualifier().isConstant()) ||
        (! limits.generalVaryingIndexing && (base->getType().getQualifier().isPipeInput() ||
                                                base->getType().getQualifier().isPipeOutput()))) {
        // it's too early to know what the inductive variables are, save it for post processing
        needsIndexLimitationChecking.push_back(index);
    }
}

// Make a shared symbol have a non-shared version that can be edited by the current
// compile, such that editing its type will not change the shared version and will
// effect all nodes sharing it.
void TParseContext::makeEditable(TSymbol*& symbol)
{
    TParseContextBase::makeEditable(symbol);

    // See if it's tied to IO resizing
    if (isIoResizeArray(symbol->getType()))
        ioArraySymbolResizeList.push_back(symbol);
}

// Return true if this is a geometry shader input array or tessellation control output array
// or mesh shader output array.
bool TParseContext::isIoResizeArray(const TType& type) const
{
    return type.isArray() &&
           ((language == EShLangGeometry    && type.getQualifier().storage == EvqVaryingIn) ||
            (language == EShLangTessControl && type.getQualifier().storage == EvqVaryingOut &&
                ! type.getQualifier().patch) ||
            (language == EShLangFragment && type.getQualifier().storage == EvqVaryingIn &&
                type.getQualifier().pervertexNV) ||
            (language == EShLangMeshNV && type.getQualifier().storage == EvqVaryingOut &&
                !type.getQualifier().perTaskNV));
}

// If an array is not isIoResizeArray() but is an io array, make sure it has the right size
void TParseContext::fixIoArraySize(const TSourceLoc& loc, TType& type)
{
    if (! type.isArray() || type.getQualifier().patch || symbolTable.atBuiltInLevel())
        return;

    assert(! isIoResizeArray(type));

    if (type.getQualifier().storage != EvqVaryingIn || type.getQualifier().patch)
        return;

    if (language == EShLangTessControl || language == EShLangTessEvaluation) {
        if (type.getOuterArraySize() != resources.maxPatchVertices) {
            if (type.isSizedArray())
                error(loc, "tessellation input array size must be gl_MaxPatchVertices or implicitly sized", "[]", "");
            type.changeOuterArraySize(resources.maxPatchVertices);
        }
    }
}

// Issue any errors if the non-array object is missing arrayness WRT
// shader I/O that has array requirements.
// All arrayness checking is handled in array paths, this is for
void TParseContext::ioArrayCheck(const TSourceLoc& loc, const TType& type, const TString& identifier)
{
    if (! type.isArray() && ! symbolTable.atBuiltInLevel()) {
        if (type.getQualifier().isArrayedIo(language) && !type.getQualifier().layoutPassthrough)
            error(loc, "type must be an array:", type.getStorageQualifierString(), identifier.c_str());
    }
}

// Handle a dereference of a geometry shader input array or tessellation control output array.
// See ioArraySymbolResizeList comment in ParseHelper.h.
//
void TParseContext::handleIoResizeArrayAccess(const TSourceLoc& /*loc*/, TIntermTyped* base)
{
    TIntermSymbol* symbolNode = base->getAsSymbolNode();
    assert(symbolNode);
    if (! symbolNode)
        return;

    // fix array size, if it can be fixed and needs to be fixed (will allow variable indexing)
    if (symbolNode->getType().isUnsizedArray()) {
        int newSize = getIoArrayImplicitSize(symbolNode->getType().getQualifier());
        if (newSize > 0)
            symbolNode->getWritableType().changeOuterArraySize(newSize);
    }
}

// If there has been an input primitive declaration (geometry shader) or an output
// number of vertices declaration(tessellation shader), make sure all input array types
// match it in size.  Types come either from nodes in the AST or symbols in the
// symbol table.
//
// Types without an array size will be given one.
// Types already having a size that is wrong will get an error.
//
void TParseContext::checkIoArraysConsistency(const TSourceLoc &loc, bool tailOnly)
{
    int requiredSize = 0;
    TString featureString;
    size_t listSize = ioArraySymbolResizeList.size();
    size_t i = 0;

    // If tailOnly = true, only check the last array symbol in the list.
    if (tailOnly) {
        i = listSize - 1;
    }
    for (bool firstIteration = true; i < listSize; ++i) {
        TType &type = ioArraySymbolResizeList[i]->getWritableType();

        // As I/O array sizes don't change, fetch requiredSize only once,
        // except for mesh shaders which could have different I/O array sizes based on type qualifiers.
        if (firstIteration || (language == EShLangMeshNV)) {
            requiredSize = getIoArrayImplicitSize(type.getQualifier(), &featureString);
            if (requiredSize == 0)
                break;
            firstIteration = false;
        }

        checkIoArrayConsistency(loc, requiredSize, featureString.c_str(), type,
                                ioArraySymbolResizeList[i]->getName());
    }
}

int TParseContext::getIoArrayImplicitSize(const TQualifier &qualifier, TString *featureString) const
{
    int expectedSize = 0;
    TString str = "unknown";
    unsigned int maxVertices = intermediate.getVertices() != TQualifier::layoutNotSet ? intermediate.getVertices() : 0;

    if (language == EShLangGeometry) {
        expectedSize = TQualifier::mapGeometryToSize(intermediate.getInputPrimitive());
        str = TQualifier::getGeometryString(intermediate.getInputPrimitive());
    }
    else if (language == EShLangTessControl) {
        expectedSize = maxVertices;
        str = "vertices";
    } else if (language == EShLangFragment) {
        // Number of vertices for Fragment shader is always three.
        expectedSize = 3;
        str = "vertices";
    } else if (language == EShLangMeshNV) {
        unsigned int maxPrimitives =
            intermediate.getPrimitives() != TQualifier::layoutNotSet ? intermediate.getPrimitives() : 0;
        if (qualifier.builtIn == EbvPrimitiveIndicesNV) {
            expectedSize = maxPrimitives * TQualifier::mapGeometryToSize(intermediate.getOutputPrimitive());
            str = "max_primitives*";
            str += TQualifier::getGeometryString(intermediate.getOutputPrimitive());
        }
        else if (qualifier.isPerPrimitive()) {
            expectedSize = maxPrimitives;
            str = "max_primitives";
        }
        else {
            expectedSize = maxVertices;
            str = "max_vertices";
        }
    }
    if (featureString)
        *featureString = str;
    return expectedSize;
}

void TParseContext::checkIoArrayConsistency(const TSourceLoc& loc, int requiredSize, const char* feature, TType& type, const TString& name)
{
    if (type.isUnsizedArray())
        type.changeOuterArraySize(requiredSize);
    else if (type.getOuterArraySize() != requiredSize) {
        if (language == EShLangGeometry)
            error(loc, "inconsistent input primitive for array size of", feature, name.c_str());
        else if (language == EShLangTessControl)
            error(loc, "inconsistent output number of vertices for array size of", feature, name.c_str());
        else if (language == EShLangFragment) {
            if (type.getOuterArraySize() > requiredSize)
                error(loc, " cannot be greater than 3 for pervertexNV", feature, name.c_str());
        }
        else if (language == EShLangMeshNV)
            error(loc, "inconsistent output array size of", feature, name.c_str());
        else
            assert(0);
    }
}

#endif // GLSLANG_WEB

// Handle seeing a binary node with a math operation.
// Returns nullptr if not semantically allowed.
TIntermTyped* TParseContext::handleBinaryMath(const TSourceLoc& loc, const char* str, TOperator op, TIntermTyped* left, TIntermTyped* right)
{
    rValueErrorCheck(loc, str, left->getAsTyped());
    rValueErrorCheck(loc, str, right->getAsTyped());

    bool allowed = true;
    switch (op) {
    // TODO: Bring more source language-specific checks up from intermediate.cpp
    // to the specific parse helpers for that source language.
    case EOpLessThan:
    case EOpGreaterThan:
    case EOpLessThanEqual:
    case EOpGreaterThanEqual:
        if (! left->isScalar() || ! right->isScalar())
            allowed = false;
        break;
    default:
        break;
    }

    if (((left->getType().contains16BitFloat() || right->getType().contains16BitFloat()) && !float16Arithmetic()) ||
        ((left->getType().contains16BitInt() || right->getType().contains16BitInt()) && !int16Arithmetic()) ||
        ((left->getType().contains8BitInt() || right->getType().contains8BitInt()) && !int8Arithmetic())) {
        allowed = false;
    }

    TIntermTyped* result = nullptr;
    if (allowed)
        result = intermediate.addBinaryMath(op, left, right, loc);

    if (result == nullptr)
        binaryOpError(loc, str, left->getCompleteString(), right->getCompleteString());

    return result;
}

// Handle seeing a unary node with a math operation.
TIntermTyped* TParseContext::handleUnaryMath(const TSourceLoc& loc, const char* str, TOperator op, TIntermTyped* childNode)
{
    rValueErrorCheck(loc, str, childNode);

    bool allowed = true;
    if ((childNode->getType().contains16BitFloat() && !float16Arithmetic()) ||
        (childNode->getType().contains16BitInt() && !int16Arithmetic()) ||
        (childNode->getType().contains8BitInt() && !int8Arithmetic())) {
        allowed = false;
    }

    TIntermTyped* result = nullptr;
    if (allowed)
        result = intermediate.addUnaryMath(op, childNode, loc);

    if (result)
        return result;
    else
        unaryOpError(loc, str, childNode->getCompleteString());

    return childNode;
}

//
// Handle seeing a base.field dereference in the grammar.
//
TIntermTyped* TParseContext::handleDotDereference(const TSourceLoc& loc, TIntermTyped* base, const TString& field)
{
    variableCheck(base);

    //
    // .length() can't be resolved until we later see the function-calling syntax.
    // Save away the name in the AST for now.  Processing is completed in
    // handleLengthMethod().
    //
    if (field == "length") {
        if (base->isArray()) {
            profileRequires(loc, ENoProfile, 120, E_GL_3DL_array_objects, ".length");
            profileRequires(loc, EEsProfile, 300, nullptr, ".length");
        } else if (base->isVector() || base->isMatrix()) {
            const char* feature = ".length() on vectors and matrices";
            requireProfile(loc, ~EEsProfile, feature);
            profileRequires(loc, ~EEsProfile, 420, E_GL_ARB_shading_language_420pack, feature);
        } else if (!base->getType().isCoopMat()) {
            error(loc, "does not operate on this type:", field.c_str(), base->getType().getCompleteString().c_str());

            return base;
        }

        return intermediate.addMethod(base, TType(EbtInt), &field, loc);
    }

    // It's not .length() if we get to here.

    if (base->isArray()) {
        error(loc, "cannot apply to an array:", ".", field.c_str());

        return base;
    }

    if (base->getType().isCoopMat()) {
        error(loc, "cannot apply to a cooperative matrix type:", ".", field.c_str());
        return base;
    }

    // It's neither an array nor .length() if we get here,
    // leaving swizzles and struct/block dereferences.

    TIntermTyped* result = base;
    if ((base->isVector() || base->isScalar()) &&
        (base->isFloatingDomain() || base->isIntegerDomain() || base->getBasicType() == EbtBool)) {
        if (base->isScalar()) {
            const char* dotFeature = "scalar swizzle";
            requireProfile(loc, ~EEsProfile, dotFeature);
            profileRequires(loc, ~EEsProfile, 420, E_GL_ARB_shading_language_420pack, dotFeature);
        }

        TSwizzleSelectors<TVectorSelector> selectors;
        parseSwizzleSelector(loc, field, base->getVectorSize(), selectors);

        if (base->isVector() && selectors.size() != 1 && base->getType().contains16BitFloat())
            requireFloat16Arithmetic(loc, ".", "can't swizzle types containing float16");
        if (base->isVector() && selectors.size() != 1 && base->getType().contains16BitInt())
            requireInt16Arithmetic(loc, ".", "can't swizzle types containing (u)int16");
        if (base->isVector() && selectors.size() != 1 && base->getType().contains8BitInt())
            requireInt8Arithmetic(loc, ".", "can't swizzle types containing (u)int8");

        if (base->isScalar()) {
            if (selectors.size() == 1)
                return result;
            else {
                TType type(base->getBasicType(), EvqTemporary, selectors.size());
                // Swizzle operations propagate specialization-constantness
                if (base->getQualifier().isSpecConstant())
                    type.getQualifier().makeSpecConstant();
                return addConstructor(loc, base, type);
            }
        }

        if (base->getType().getQualifier().isFrontEndConstant())
            result = intermediate.foldSwizzle(base, selectors, loc);
        else {
            if (selectors.size() == 1) {
                TIntermTyped* index = intermediate.addConstantUnion(selectors[0], loc);
                result = intermediate.addIndex(EOpIndexDirect, base, index, loc);
                result->setType(TType(base->getBasicType(), EvqTemporary, base->getType().getQualifier().precision));
            } else {
                TIntermTyped* index = intermediate.addSwizzle(selectors, loc);
                result = intermediate.addIndex(EOpVectorSwizzle, base, index, loc);
                result->setType(TType(base->getBasicType(), EvqTemporary, base->getType().getQualifier().precision, selectors.size()));
            }
            // Swizzle operations propagate specialization-constantness
            if (base->getType().getQualifier().isSpecConstant())
                result->getWritableType().getQualifier().makeSpecConstant();
        }
    } else if (base->isStruct() || base->isReference()) {
        const TTypeList* fields = base->isReference() ?
                                  base->getType().getReferentType()->getStruct() :
                                  base->getType().getStruct();
        bool fieldFound = false;
        int member;
        for (member = 0; member < (int)fields->size(); ++member) {
            if ((*fields)[member].type->getFieldName() == field) {
                fieldFound = true;
                break;
            }
        }
        if (fieldFound) {
            if (base->getType().getQualifier().isFrontEndConstant())
                result = intermediate.foldDereference(base, member, loc);
            else {
                blockMemberExtensionCheck(loc, base, member, field);
                TIntermTyped* index = intermediate.addConstantUnion(member, loc);
                result = intermediate.addIndex(EOpIndexDirectStruct, base, index, loc);
                result->setType(*(*fields)[member].type);
                if ((*fields)[member].type->getQualifier().isIo())
                    intermediate.addIoAccessed(field);
            }
            inheritMemoryQualifiers(base->getQualifier(), result->getWritableType().getQualifier());
        } else
            error(loc, "no such field in structure", field.c_str(), "");
    } else
        error(loc, "does not apply to this type:", field.c_str(), base->getType().getCompleteString().c_str());

    // Propagate noContraction up the dereference chain
    if (base->getQualifier().isNoContraction())
        result->getWritableType().getQualifier().setNoContraction();

    // Propagate nonuniform
    if (base->getQualifier().isNonUniform())
        result->getWritableType().getQualifier().nonUniform = true;

    return result;
}

void TParseContext::blockMemberExtensionCheck(const TSourceLoc& loc, const TIntermTyped* base, int member, const TString& memberName)
{
    // a block that needs extension checking is either 'base', or if arrayed,
    // one level removed to the left
    const TIntermSymbol* baseSymbol = nullptr;
    if (base->getAsBinaryNode() == nullptr)
        baseSymbol = base->getAsSymbolNode();
    else
        baseSymbol = base->getAsBinaryNode()->getLeft()->getAsSymbolNode();
    if (baseSymbol == nullptr)
        return;
    const TSymbol* symbol = symbolTable.find(baseSymbol->getName());
    if (symbol == nullptr)
        return;
    const TVariable* variable = symbol->getAsVariable();
    if (variable == nullptr)
        return;
    if (!variable->hasMemberExtensions())
        return;

    // We now have a variable that is the base of a dot reference
    // with members that need extension checking.
    if (variable->getNumMemberExtensions(member) > 0)
        requireExtensions(loc, variable->getNumMemberExtensions(member), variable->getMemberExtensions(member), memberName.c_str());
}

//
// Handle seeing a function declarator in the grammar.  This is the precursor
// to recognizing a function prototype or function definition.
//
TFunction* TParseContext::handleFunctionDeclarator(const TSourceLoc& loc, TFunction& function, bool prototype)
{
    // ES can't declare prototypes inside functions
    if (! symbolTable.atGlobalLevel())
        requireProfile(loc, ~EEsProfile, "local function declaration");

    //
    // Multiple declarations of the same function name are allowed.
    //
    // If this is a definition, the definition production code will check for redefinitions
    // (we don't know at this point if it's a definition or not).
    //
    // Redeclarations (full signature match) are allowed.  But, return types and parameter qualifiers must also match.
    //  - except ES 100, which only allows a single prototype
    //
    // ES 100 does not allow redefining, but does allow overloading of built-in functions.
    // ES 300 does not allow redefining or overloading of built-in functions.
    //
    bool builtIn;
    TSymbol* symbol = symbolTable.find(function.getMangledName(), &builtIn);
    if (symbol && symbol->getAsFunction() && builtIn)
        requireProfile(loc, ~EEsProfile, "redefinition of built-in function");
    const TFunction* prevDec = symbol ? symbol->getAsFunction() : 0;
    if (prevDec) {
        if (prevDec->isPrototyped() && prototype)
            profileRequires(loc, EEsProfile, 300, nullptr, "multiple prototypes for same function");
        if (prevDec->getType() != function.getType())
            error(loc, "overloaded functions must have the same return type", function.getName().c_str(), "");
        for (int i = 0; i < prevDec->getParamCount(); ++i) {
            if ((*prevDec)[i].type->getQualifier().storage != function[i].type->getQualifier().storage)
                error(loc, "overloaded functions must have the same parameter storage qualifiers for argument", function[i].type->getStorageQualifierString(), "%d", i+1);

            if ((*prevDec)[i].type->getQualifier().precision != function[i].type->getQualifier().precision)
                error(loc, "overloaded functions must have the same parameter precision qualifiers for argument", function[i].type->getPrecisionQualifierString(), "%d", i+1);
        }
    }

    arrayObjectCheck(loc, function.getType(), "array in function return type");

    if (prototype) {
        // All built-in functions are defined, even though they don't have a body.
        // Count their prototype as a definition instead.
        if (symbolTable.atBuiltInLevel())
            function.setDefined();
        else {
            if (prevDec && ! builtIn)
                symbol->getAsFunction()->setPrototyped();  // need a writable one, but like having prevDec as a const
            function.setPrototyped();
        }
    }

    // This insert won't actually insert it if it's a duplicate signature, but it will still check for
    // other forms of name collisions.
    if (! symbolTable.insert(function))
        error(loc, "function name is redeclaration of existing name", function.getName().c_str(), "");

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

//
// Handle seeing the function prototype in front of a function definition in the grammar.
// The body is handled after this function returns.
//
TIntermAggregate* TParseContext::handleFunctionDefinition(const TSourceLoc& loc, TFunction& function)
{
    currentCaller = function.getMangledName();
    TSymbol* symbol = symbolTable.find(function.getMangledName());
    TFunction* prevDec = symbol ? symbol->getAsFunction() : nullptr;

    if (! prevDec)
        error(loc, "can't find function", function.getName().c_str(), "");
    // 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 occurrence.

    if (prevDec && prevDec->isDefined()) {
        // Then this function already has a body.
        error(loc, "function already has a body", function.getName().c_str(), "");
    }
    if (prevDec && ! prevDec->isDefined()) {
        prevDec->setDefined();

        // Remember the return type for later checking for RETURN statements.
        currentFunctionType = &(prevDec->getType());
    } else
        currentFunctionType = new TType(EbtVoid);
    functionReturnsValue = false;

    // Check for entry point
    if (function.getName().compare(intermediate.getEntryPointName().c_str()) == 0) {
        intermediate.setEntryPointMangledName(function.getMangledName().c_str());
        intermediate.incrementEntryPointCount();
        inMain = true;
    } else
        inMain = false;

    //
    // Raise error message if main function takes any parameters or returns anything other than void
    //
    if (inMain) {
        if (function.getParamCount() > 0)
            error(loc, "function cannot take any parameter(s)", function.getName().c_str(), "");
        if (function.getType().getBasicType() != EbtVoid)
            error(loc, "", function.getType().getBasicTypeString().c_str(), "entry point cannot return a value");
    }

    //
    // New symbol table scope for body of function plus its arguments
    //
    symbolTable.push();

    //
    // 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 (int i = 0; i < function.getParamCount(); i++) {
        TParameter& param = function[i];
        if (param.name != nullptr) {
            TVariable *variable = new TVariable(param.name, *param.type);

            // Insert the parameters with name in the symbol table.
            if (! symbolTable.insert(*variable))
                error(loc, "redefinition", variable->getName().c_str(), "");
            else {
                // Transfer ownership of name pointer to symbol table.
                param.name = nullptr;

                // Add the parameter to the HIL
                paramNodes = intermediate.growAggregate(paramNodes,
                                                        intermediate.addSymbol(*variable, loc),
                                                        loc);
            }
        } else
            paramNodes = intermediate.growAggregate(paramNodes, intermediate.addSymbol(*param.type, loc), loc);
    }
    intermediate.setAggregateOperator(paramNodes, EOpParameters, TType(EbtVoid), loc);
    loopNestingLevel = 0;
    statementNestingLevel = 0;
    controlFlowNestingLevel = 0;
    postEntryPointReturn = false;

    return paramNodes;
}

//
// Handle seeing function call syntax in the grammar, which could be any of
//  - .length() method
//  - constructor
//  - a call to a built-in function mapped to an operator
//  - a call to a built-in function that will remain a function call (e.g., texturing)
//  - user function
//  - subroutine call (not implemented yet)
//
TIntermTyped* TParseContext::handleFunctionCall(const TSourceLoc& loc, TFunction* function, TIntermNode* arguments)
{
    TIntermTyped* result = nullptr;

    if (function->getBuiltInOp() == EOpArrayLength)
        result = handleLengthMethod(loc, function, arguments);
    else if (function->getBuiltInOp() != EOpNull) {
        //
        // Then this should be a constructor.
        // Don't go through the symbol table for constructors.
        // Their parameters will be verified algorithmically.
        //
        TType type(EbtVoid);  // use this to get the type back
        if (! constructorError(loc, arguments, *function, function->getBuiltInOp(), type)) {
            //
            // It's a constructor, of type 'type'.
            //
            result = addConstructor(loc, arguments, type);
            if (result == nullptr)
                error(loc, "cannot construct with these arguments", type.getCompleteString().c_str(), "");
        }
    } else {
        //
        // Find it in the symbol table.
        //
        const TFunction* fnCandidate;
        bool builtIn;
        fnCandidate = findFunction(loc, *function, builtIn);
        if (fnCandidate) {
            // This is a declared function that might map to
            //  - a built-in operator,
            //  - a built-in function not mapped to an operator, or
            //  - a user function.

            // Error check for a function requiring specific extensions present.
            if (builtIn && fnCandidate->getNumExtensions())
                requireExtensions(loc, fnCandidate->getNumExtensions(), fnCandidate->getExtensions(), fnCandidate->getName().c_str());

            if (builtIn && fnCandidate->getType().contains16BitFloat())
                requireFloat16Arithmetic(loc, "built-in function", "float16 types can only be in uniform block or buffer storage");
            if (builtIn && fnCandidate->getType().contains16BitInt())
                requireInt16Arithmetic(loc, "built-in function", "(u)int16 types can only be in uniform block or buffer storage");
            if (builtIn && fnCandidate->getType().contains8BitInt())
                requireInt8Arithmetic(loc, "built-in function", "(u)int8 types can only be in uniform block or buffer storage");

            if (arguments != nullptr) {
                // Make sure qualifications work for these arguments.
                TIntermAggregate* aggregate = arguments->getAsAggregate();
                for (int i = 0; i < fnCandidate->getParamCount(); ++i) {
                    // At this early point there is a slight ambiguity between whether an aggregate 'arguments'
                    // is the single argument itself or its children are the arguments.  Only one argument
                    // means take 'arguments' itself as the one argument.
                    TIntermNode* arg = fnCandidate->getParamCount() == 1 ? arguments : (aggregate ? aggregate->getSequence()[i] : arguments);
                    TQualifier& formalQualifier = (*fnCandidate)[i].type->getQualifier();
                    if (formalQualifier.isParamOutput()) {
                        if (lValueErrorCheck(arguments->getLoc(), "assign", arg->getAsTyped()))
                            error(arguments->getLoc(), "Non-L-value cannot be passed for 'out' or 'inout' parameters.", "out", "");
                    }
                    const TType& argType = arg->getAsTyped()->getType();
                    const TQualifier& argQualifier = argType.getQualifier();
                    if (argQualifier.isMemory() && (argType.containsOpaque() || argType.isReference())) {
                        const char* message = "argument cannot drop memory qualifier when passed to formal parameter";
                        if (argQualifier.volatil && ! formalQualifier.volatil)
                            error(arguments->getLoc(), message, "volatile", "");
                        if (argQualifier.coherent && ! (formalQualifier.devicecoherent || formalQualifier.coherent))
                            error(arguments->getLoc(), message, "coherent", "");
                        if (argQualifier.devicecoherent && ! (formalQualifier.devicecoherent || formalQualifier.coherent))
                            error(arguments->getLoc(), message, "devicecoherent", "");
                        if (argQualifier.queuefamilycoherent && ! (formalQualifier.queuefamilycoherent || formalQualifier.devicecoherent || formalQualifier.coherent))
                            error(arguments->getLoc(), message, "queuefamilycoherent", "");
                        if (argQualifier.workgroupcoherent && ! (formalQualifier.workgroupcoherent || formalQualifier.queuefamilycoherent || formalQualifier.devicecoherent || formalQualifier.coherent))
                            error(arguments->getLoc(), message, "workgroupcoherent", "");
                        if (argQualifier.subgroupcoherent && ! (formalQualifier.subgroupcoherent || formalQualifier.workgroupcoherent || formalQualifier.queuefamilycoherent || formalQualifier.devicecoherent || formalQualifier.coherent))
                            error(arguments->getLoc(), message, "subgroupcoherent", "");
                        if (argQualifier.readonly && ! formalQualifier.readonly)
                            error(arguments->getLoc(), message, "readonly", "");
                        if (argQualifier.writeonly && ! formalQualifier.writeonly)
                            error(arguments->getLoc(), message, "writeonly", "");
                        // Don't check 'restrict', it is different than the rest:
                        // "...but only restrict can be taken away from a calling argument, by a formal parameter that
                        // lacks the restrict qualifier..."
                    }
                    if (!builtIn && argQualifier.getFormat() != formalQualifier.getFormat()) {
                        // we have mismatched formats, which should only be allowed if writeonly
                        // and at least one format is unknown
                        if (!formalQualifier.isWriteOnly() || (formalQualifier.getFormat() != ElfNone &&
                                                                  argQualifier.getFormat() != ElfNone))
                            error(arguments->getLoc(), "image formats must match", "format", "");
                    }
                    if (builtIn && arg->getAsTyped()->getType().contains16BitFloat())
                        requireFloat16Arithmetic(arguments->getLoc(), "built-in function", "float16 types can only be in uniform block or buffer storage");
                    if (builtIn && arg->getAsTyped()->getType().contains16BitInt())
                        requireInt16Arithmetic(arguments->getLoc(), "built-in function", "(u)int16 types can only be in uniform block or buffer storage");
                    if (builtIn && arg->getAsTyped()->getType().contains8BitInt())
                        requireInt8Arithmetic(arguments->getLoc(), "built-in function", "(u)int8 types can only be in uniform block or buffer storage");

                    // TODO 4.5 functionality:  A shader will fail to compile
                    // if the value passed to the memargument of an atomic memory function does not correspond to a buffer or
                    // shared variable. It is acceptable to pass an element of an array or a single component of a vector to the
                    // memargument of an atomic memory function, as long as the underlying array or vector is a buffer or
                    // shared variable.
                }

                // Convert 'in' arguments
                addInputArgumentConversions(*fnCandidate, arguments);  // arguments may be modified if it's just a single argument node
            }

            if (builtIn && fnCandidate->getBuiltInOp() != EOpNull) {
                // A function call mapped to a built-in operation.
                result = handleBuiltInFunctionCall(loc, arguments, *fnCandidate);
            } else {
                // This is a function call not mapped to built-in operator.
                // It could still be a built-in function, but only if PureOperatorBuiltins == false.
                result = intermediate.setAggregateOperator(arguments, EOpFunctionCall, fnCandidate->getType(), loc);
                TIntermAggregate* call = result->getAsAggregate();
                call->setName(fnCandidate->getMangledName());

                // this is how we know whether the given function is a built-in function or a user-defined function
                // if builtIn == false, it's a userDefined -> could be an overloaded built-in function also
                // if builtIn == true, it's definitely a built-in function with EOpNull
                if (! builtIn) {
                    call->setUserDefined();
                    if (symbolTable.atGlobalLevel()) {
                        requireProfile(loc, ~EEsProfile, "calling user function from global scope");
                        intermediate.addToCallGraph(infoSink, "main(", fnCandidate->getMangledName());
                    } else
                        intermediate.addToCallGraph(infoSink, currentCaller, fnCandidate->getMangledName());
                }

#ifndef GLSLANG_WEB
                if (builtIn)
                    nonOpBuiltInCheck(loc, *fnCandidate, *call);
                else
#endif
                    userFunctionCallCheck(loc, *call);
            }

            // Convert 'out' arguments.  If it was a constant folded built-in, it won't be an aggregate anymore.
            // Built-ins with a single argument aren't called with an aggregate, but they also don't have an output.
            // Also, build the qualifier list for user function calls, which are always called with an aggregate.
            if (result->getAsAggregate()) {
                TQualifierList& qualifierList = result->getAsAggregate()->getQualifierList();
                for (int i = 0; i < fnCandidate->getParamCount(); ++i) {
                    TStorageQualifier qual = (*fnCandidate)[i].type->getQualifier().storage;
                    qualifierList.push_back(qual);
                }
                result = addOutputArgumentConversions(*fnCandidate, *result->getAsAggregate());
            }

            if (result->getAsTyped()->getType().isCoopMat() &&
               !result->getAsTyped()->getType().isParameterized()) {
                assert(fnCandidate->getBuiltInOp() == EOpCooperativeMatrixMulAdd);

                result->setType(result->getAsAggregate()->getSequence()[2]->getAsTyped()->getType());
            }
        }
    }

    // generic error recovery
    // TODO: simplification: localize all the error recoveries that look like this, and taking type into account to reduce cascades
    if (result == nullptr)
        result = intermediate.addConstantUnion(0.0, EbtFloat, loc);

    return result;
}

TIntermTyped* TParseContext::handleBuiltInFunctionCall(TSourceLoc loc, TIntermNode* arguments,
                                                       const TFunction& function)
{
    checkLocation(loc, function.getBuiltInOp());
    TIntermTyped *result = intermediate.addBuiltInFunctionCall(loc, function.getBuiltInOp(),
                                                               function.getParamCount() == 1,
                                                               arguments, function.getType());
    if (obeyPrecisionQualifiers())
        computeBuiltinPrecisions(*result, function);

    if (result == nullptr) {
        if (arguments == nullptr)
            error(loc, " wrong operand type", "Internal Error",
                                      "built in unary operator function.  Type: %s", "");
        else
            error(arguments->getLoc(), " wrong operand type", "Internal Error",
                                      "built in unary operator function.  Type: %s",
                                      static_cast<TIntermTyped*>(arguments)->getCompleteString().c_str());
    } else if (result->getAsOperator())
        builtInOpCheck(loc, function, *result->getAsOperator());

    return result;
}

// "The operation of a built-in function can have a different precision
// qualification than the precision qualification of the resulting value.
// These two precision qualifications are established as follows.
//
// The precision qualification of the operation of a built-in function is
// based on the precision qualification of its input arguments and formal
// parameters:  When a formal parameter specifies a precision qualifier,
// that is used, otherwise, the precision qualification of the calling
// argument is used.  The highest precision of these will be the precision
// qualification of the operation of the built-in function. Generally,
// this is applied across all arguments to a built-in function, with the
// exceptions being:
//   - bitfieldExtract and bitfieldInsert ignore the 'offset' and 'bits'
//     arguments.
//   - interpolateAt* functions only look at the 'interpolant' argument.
//
// The precision qualification of the result of a built-in function is
// determined in one of the following ways:
//
//   - For the texture sampling, image load, and image store functions,
//     the precision of the return type matches the precision of the
//     sampler type
//
//   Otherwise:
//
//   - For prototypes that do not specify a resulting precision qualifier,
//     the precision will be the same as the precision of the operation.
//
//   - For prototypes that do specify a resulting precision qualifier,
//     the specified precision qualifier is the precision qualification of
//     the result."
//
void TParseContext::computeBuiltinPrecisions(TIntermTyped& node, const TFunction& function)
{
    TPrecisionQualifier operationPrecision = EpqNone;
    TPrecisionQualifier resultPrecision = EpqNone;

    TIntermOperator* opNode = node.getAsOperator();
    if (opNode == nullptr)
        return;

    if (TIntermUnary* unaryNode = node.getAsUnaryNode()) {
        operationPrecision = std::max(function[0].type->getQualifier().precision,
                                      unaryNode->getOperand()->getType().getQualifier().precision);
        if (function.getType().getBasicType() != EbtBool)
            resultPrecision = function.getType().getQualifier().precision == EpqNone ?
                                        operationPrecision :
                                        function.getType().getQualifier().precision;
    } else if (TIntermAggregate* agg = node.getAsAggregate()) {
        TIntermSequence& sequence = agg->getSequence();
        unsigned int numArgs = (unsigned int)sequence.size();
        switch (agg->getOp()) {
        case EOpBitfieldExtract:
            numArgs = 1;
            break;
        case EOpBitfieldInsert:
            numArgs = 2;
            break;
        case EOpInterpolateAtCentroid:
        case EOpInterpolateAtOffset:
        case EOpInterpolateAtSample:
            numArgs = 1;
            break;
        default:
            break;
        }
        // find the maximum precision from the arguments and parameters
        for (unsigned int arg = 0; arg < numArgs; ++arg) {
            operationPrecision = std::max(operationPrecision, sequence[arg]->getAsTyped()->getQualifier().precision);
            operationPrecision = std::max(operationPrecision, function[arg].type->getQualifier().precision);
        }
        // compute the result precision
        if (agg->isSampling() ||
            agg->getOp() == EOpImageLoad || agg->getOp() == EOpImageStore ||
            agg->getOp() == EOpImageLoadLod || agg->getOp() == EOpImageStoreLod)
            resultPrecision = sequence[0]->getAsTyped()->getQualifier().precision;
        else if (function.getType().getBasicType() != EbtBool)
            resultPrecision = function.getType().getQualifier().precision == EpqNone ?
                                        operationPrecision :
                                        function.getType().getQualifier().precision;
    }

    // Propagate precision through this node and its children. That algorithm stops
    // when a precision is found, so start by clearing this subroot precision
    opNode->getQualifier().precision = EpqNone;
    if (operationPrecision != EpqNone) {
        opNode->propagatePrecision(operationPrecision);
        opNode->setOperationPrecision(operationPrecision);
    }
    // Now, set the result precision, which might not match
    opNode->getQualifier().precision = resultPrecision;
}

TIntermNode* TParseContext::handleReturnValue(const TSourceLoc& loc, TIntermTyped* value)
{
#ifndef GLSLANG_WEB
    storage16BitAssignmentCheck(loc, value->getType(), "return");
#endif

    functionReturnsValue = true;
    if (currentFunctionType->getBasicType() == EbtVoid) {
        error(loc, "void function cannot return a value", "return", "");
        return intermediate.addBranch(EOpReturn, loc);
    } else if (*currentFunctionType != value->getType()) {
        TIntermTyped* converted = intermediate.addConversion(EOpReturn, *currentFunctionType, value);
        if (converted) {
            if (*currentFunctionType != converted->getType())
                error(loc, "cannot convert return value to function return type", "return", "");
            if (version < 420)
                warn(loc, "type conversion on return values was not explicitly allowed until version 420", "return", "");
            return intermediate.addBranch(EOpReturn, converted, loc);
        } else {
            error(loc, "type does not match, or is not convertible to, the function's return type", "return", "");
            return intermediate.addBranch(EOpReturn, value, loc);
        }
    } else
        return intermediate.addBranch(EOpReturn, value, loc);
}

// See if the operation is being done in an illegal location.
void TParseContext::checkLocation(const TSourceLoc& loc, TOperator op)
{
#ifndef GLSLANG_WEB
    switch (op) {
    case EOpBarrier:
        if (language == EShLangTessControl) {
            if (controlFlowNestingLevel > 0)
                error(loc, "tessellation control barrier() cannot be placed within flow control", "", "");
            if (! inMain)
                error(loc, "tessellation control barrier() must be in main()", "", "");
            else if (postEntryPointReturn)
                error(loc, "tessellation control barrier() cannot be placed after a return from main()", "", "");
        }
        break;
    case EOpBeginInvocationInterlock:
        if (language != EShLangFragment)
            error(loc, "beginInvocationInterlockARB() must be in a fragment shader", "", "");
        if (! inMain)
            error(loc, "beginInvocationInterlockARB() must be in main()", "", "");
        else if (postEntryPointReturn)
            error(loc, "beginInvocationInterlockARB() cannot be placed after a return from main()", "", "");
        if (controlFlowNestingLevel > 0)
            error(loc, "beginInvocationInterlockARB() cannot be placed within flow control", "", "");

        if (beginInvocationInterlockCount > 0)
            error(loc, "beginInvocationInterlockARB() must only be called once", "", "");
        if (endInvocationInterlockCount > 0)
            error(loc, "beginInvocationInterlockARB() must be called before endInvocationInterlockARB()", "", "");

        beginInvocationInterlockCount++;

        // default to pixel_interlock_ordered
        if (intermediate.getInterlockOrdering() == EioNone)
            intermediate.setInterlockOrdering(EioPixelInterlockOrdered);
        break;
    case EOpEndInvocationInterlock:
        if (language != EShLangFragment)
            error(loc, "endInvocationInterlockARB() must be in a fragment shader", "", "");
        if (! inMain)
            error(loc, "endInvocationInterlockARB() must be in main()", "", "");
        else if (postEntryPointReturn)
            error(loc, "endInvocationInterlockARB() cannot be placed after a return from main()", "", "");
        if (controlFlowNestingLevel > 0)
            error(loc, "endInvocationInterlockARB() cannot be placed within flow control", "", "");

        if (endInvocationInterlockCount > 0)
            error(loc, "endInvocationInterlockARB() must only be called once", "", "");
        if (beginInvocationInterlockCount == 0)
            error(loc, "beginInvocationInterlockARB() must be called before endInvocationInterlockARB()", "", "");

        endInvocationInterlockCount++;
        break;
    default:
        break;
    }
#endif
}

// Finish processing object.length(). This started earlier in handleDotDereference(), where
// the ".length" part was recognized and semantically checked, and finished here where the
// function syntax "()" is recognized.
//
// Return resulting tree node.
TIntermTyped* TParseContext::handleLengthMethod(const TSourceLoc& loc, TFunction* function, TIntermNode* intermNode)
{
    int length = 0;

    if (function->getParamCount() > 0)
        error(loc, "method does not accept any arguments", function->getName().c_str(), "");
    else {
        const TType& type = intermNode->getAsTyped()->getType();
        if (type.isArray()) {
            if (type.isUnsizedArray()) {
#ifndef GLSLANG_WEB
                if (intermNode->getAsSymbolNode() && isIoResizeArray(type)) {
                    // We could be between a layout declaration that gives a built-in io array implicit size and
                    // a user redeclaration of that array, meaning we have to substitute its implicit size here
                    // without actually redeclaring the array.  (It is an error to use a member before the
                    // redeclaration, but not an error to use the array name itself.)
                    const TString& name = intermNode->getAsSymbolNode()->getName();
                    if (name == "gl_in" || name == "gl_out" || name == "gl_MeshVerticesNV" ||
                        name == "gl_MeshPrimitivesNV") {
                        length = getIoArrayImplicitSize(type.getQualifier());
                    }
                }
#endif
                if (length == 0) {
#ifndef GLSLANG_WEB
                    if (intermNode->getAsSymbolNode() && isIoResizeArray(type))
                        error(loc, "", function->getName().c_str(), "array must first be sized by a redeclaration or layout qualifier");
                    else if (isRuntimeLength(*intermNode->getAsTyped())) {
                        // Create a unary op and let the back end handle it
                        return intermediate.addBuiltInFunctionCall(loc, EOpArrayLength, true, intermNode, TType(EbtInt));
                    } else
#endif
                        error(loc, "", function->getName().c_str(), "array must be declared with a size before using this method");
                }
            } else if (type.getOuterArrayNode()) {
                // If the array's outer size is specified by an intermediate node, it means the array's length
                // was specified by a specialization constant. In such a case, we should return the node of the
                // specialization constants to represent the length.
                return type.getOuterArrayNode();
            } else
                length = type.getOuterArraySize();
        } else if (type.isMatrix())
            length = type.getMatrixCols();
        else if (type.isVector())
            length = type.getVectorSize();
        else if (type.isCoopMat())
            return intermediate.addBuiltInFunctionCall(loc, EOpArrayLength, true, intermNode, TType(EbtInt));
        else {
            // we should not get here, because earlier semantic checking should have prevented this path
            error(loc, ".length()", "unexpected use of .length()", "");
        }
    }

    if (length == 0)
        length = 1;

    return intermediate.addConstantUnion(length, loc);
}

//
// Add any needed implicit conversions for function-call arguments to input parameters.
//
void TParseContext::addInputArgumentConversions(const TFunction& function, TIntermNode*& arguments) const
{
#ifndef GLSLANG_WEB
    TIntermAggregate* aggregate = arguments->getAsAggregate();

    // Process each argument's conversion
    for (int i = 0; i < function.getParamCount(); ++i) {
        // At this early point there is a slight ambiguity between whether an aggregate 'arguments'
        // is the single argument itself or its children are the arguments.  Only one argument
        // means take 'arguments' itself as the one argument.
        TIntermTyped* arg = function.getParamCount() == 1 ? arguments->getAsTyped() : (aggregate ? aggregate->getSequence()[i]->getAsTyped() : arguments->getAsTyped());
        if (*function[i].type != arg->getType()) {
            if (function[i].type->getQualifier().isParamInput() &&
               !function[i].type->isCoopMat()) {
                // In-qualified arguments just need an extra node added above the argument to
                // convert to the correct type.
                arg = intermediate.addConversion(EOpFunctionCall, *function[i].type, arg);
                if (arg) {
                    if (function.getParamCount() == 1)
                        arguments = arg;
                    else {
                        if (aggregate)
                            aggregate->getSequence()[i] = arg;
                        else
                            arguments = arg;
                    }
                }
            }
        }
    }
#endif
}

//
// Add any needed implicit output conversions for function-call arguments.  This
// can require a new tree topology, complicated further by whether the function
// has a return value.
//
// Returns a node of a subtree that evaluates to the return value of the function.
//
TIntermTyped* TParseContext::addOutputArgumentConversions(const TFunction& function, TIntermAggregate& intermNode) const
{
#ifdef GLSLANG_WEB
    return &intermNode;
#else
    TIntermSequence& arguments = intermNode.getSequence();

    // Will there be any output conversions?
    bool outputConversions = false;
    for (int i = 0; i < function.getParamCount(); ++i) {
        if (*function[i].type != arguments[i]->getAsTyped()->getType() && function[i].type->getQualifier().isParamOutput()) {
            outputConversions = true;
            break;
        }
    }

    if (! outputConversions)
        return &intermNode;

    // Setup for the new tree, if needed:
    //
    // Output conversions need a different tree topology.
    // Out-qualified arguments need a temporary of the correct type, with the call
    // followed by an assignment of the temporary to the original argument:
    //     void: function(arg, ...)  ->        (          function(tempArg, ...), arg = tempArg, ...)
    //     ret = function(arg, ...)  ->  ret = (tempRet = function(tempArg, ...), arg = tempArg, ..., tempRet)
    // Where the "tempArg" type needs no conversion as an argument, but will convert on assignment.
    TIntermTyped* conversionTree = nullptr;
    TVariable* tempRet = nullptr;
    if (intermNode.getBasicType() != EbtVoid) {
        // do the "tempRet = function(...), " bit from above
        tempRet = makeInternalVariable("tempReturn", intermNode.getType());
        TIntermSymbol* tempRetNode = intermediate.addSymbol(*tempRet, intermNode.getLoc());
        conversionTree = intermediate.addAssign(EOpAssign, tempRetNode, &intermNode, intermNode.getLoc());
    } else
        conversionTree = &intermNode;

    conversionTree = intermediate.makeAggregate(conversionTree);

    // Process each argument's conversion
    for (int i = 0; i < function.getParamCount(); ++i) {
        if (*function[i].type != arguments[i]->getAsTyped()->getType()) {
            if (function[i].type->getQualifier().isParamOutput()) {
                // Out-qualified arguments need to use the topology set up above.
                // do the " ...(tempArg, ...), arg = tempArg" bit from above
                TType paramType;
                paramType.shallowCopy(*function[i].type);
                if (arguments[i]->getAsTyped()->getType().isParameterized() &&
                    !paramType.isParameterized()) {
                    paramType.shallowCopy(arguments[i]->getAsTyped()->getType());
                    paramType.copyTypeParameters(*arguments[i]->getAsTyped()->getType().getTypeParameters());
                }
                TVariable* tempArg = makeInternalVariable("tempArg", paramType);
                tempArg->getWritableType().getQualifier().makeTemporary();
                TIntermSymbol* tempArgNode = intermediate.addSymbol(*tempArg, intermNode.getLoc());
                TIntermTyped* tempAssign = intermediate.addAssign(EOpAssign, arguments[i]->getAsTyped(), tempArgNode, arguments[i]->getLoc());
                conversionTree = intermediate.growAggregate(conversionTree, tempAssign, arguments[i]->getLoc());
                // replace the argument with another node for the same tempArg variable
                arguments[i] = intermediate.addSymbol(*tempArg, intermNode.getLoc());
            }
        }
    }

    // Finalize the tree topology (see bigger comment above).
    if (tempRet) {
        // do the "..., tempRet" bit from above
        TIntermSymbol* tempRetNode = intermediate.addSymbol(*tempRet, intermNode.getLoc());
        conversionTree = intermediate.growAggregate(conversionTree, tempRetNode, intermNode.getLoc());
    }
    conversionTree = intermediate.setAggregateOperator(conversionTree, EOpComma, intermNode.getType(), intermNode.getLoc());

    return conversionTree;
#endif
}

void TParseContext::memorySemanticsCheck(const TSourceLoc& loc, const TFunction& fnCandidate, const TIntermOperator& callNode)
{
    const TIntermSequence* argp = &callNode.getAsAggregate()->getSequence();

    //const int gl_SemanticsRelaxed         = 0x0;
    const int gl_SemanticsAcquire         = 0x2;
    const int gl_SemanticsRelease         = 0x4;
    const int gl_SemanticsAcquireRelease  = 0x8;
    const int gl_SemanticsMakeAvailable   = 0x2000;
    const int gl_SemanticsMakeVisible     = 0x4000;
    const int gl_SemanticsVolatile        = 0x8000;

    //const int gl_StorageSemanticsNone     = 0x0;
    const int gl_StorageSemanticsBuffer   = 0x40;
    const int gl_StorageSemanticsShared   = 0x100;
    const int gl_StorageSemanticsImage    = 0x800;
    const int gl_StorageSemanticsOutput   = 0x1000;


    unsigned int semantics = 0, storageClassSemantics = 0;
    unsigned int semantics2 = 0, storageClassSemantics2 = 0;

    // Grab the semantics and storage class semantics from the operands, based on opcode
    switch (callNode.getOp()) {
    case EOpAtomicAdd:
    case EOpAtomicMin:
    case EOpAtomicMax:
    case EOpAtomicAnd:
    case EOpAtomicOr:
    case EOpAtomicXor:
    case EOpAtomicExchange:
    case EOpAtomicStore:
        storageClassSemantics = (*argp)[3]->getAsConstantUnion()->getConstArray()[0].getIConst();
        semantics = (*argp)[4]->getAsConstantUnion()->getConstArray()[0].getIConst();
        break;
    case EOpAtomicLoad:
        storageClassSemantics = (*argp)[2]->getAsConstantUnion()->getConstArray()[0].getIConst();
        semantics = (*argp)[3]->getAsConstantUnion()->getConstArray()[0].getIConst();
        break;
    case EOpAtomicCompSwap:
        storageClassSemantics = (*argp)[4]->getAsConstantUnion()->getConstArray()[0].getIConst();
        semantics = (*argp)[5]->getAsConstantUnion()->getConstArray()[0].getIConst();
        storageClassSemantics2 = (*argp)[6]->getAsConstantUnion()->getConstArray()[0].getIConst();
        semantics2 = (*argp)[7]->getAsConstantUnion()->getConstArray()[0].getIConst();
        break;

    case EOpImageAtomicAdd:
    case EOpImageAtomicMin:
    case EOpImageAtomicMax:
    case EOpImageAtomicAnd:
    case EOpImageAtomicOr:
    case EOpImageAtomicXor:
    case EOpImageAtomicExchange:
    case EOpImageAtomicStore:
        storageClassSemantics = (*argp)[4]->getAsConstantUnion()->getConstArray()[0].getIConst();
        semantics = (*argp)[5]->getAsConstantUnion()->getConstArray()[0].getIConst();
        break;
    case EOpImageAtomicLoad:
        storageClassSemantics = (*argp)[3]->getAsConstantUnion()->getConstArray()[0].getIConst();
        semantics = (*argp)[4]->getAsConstantUnion()->getConstArray()[0].getIConst();
        break;
    case EOpImageAtomicCompSwap:
        storageClassSemantics = (*argp)[5]->getAsConstantUnion()->getConstArray()[0].getIConst();
        semantics = (*argp)[6]->getAsConstantUnion()->getConstArray()[0].getIConst();
        storageClassSemantics2 = (*argp)[7]->getAsConstantUnion()->getConstArray()[0].getIConst();
        semantics2 = (*argp)[8]->getAsConstantUnion()->getConstArray()[0].getIConst();
        break;

    case EOpBarrier:
        storageClassSemantics = (*argp)[2]->getAsConstantUnion()->getConstArray()[0].getIConst();
        semantics = (*argp)[3]->getAsConstantUnion()->getConstArray()[0].getIConst();
        break;
    case EOpMemoryBarrier:
        storageClassSemantics = (*argp)[1]->getAsConstantUnion()->getConstArray()[0].getIConst();
        semantics = (*argp)[2]->getAsConstantUnion()->getConstArray()[0].getIConst();
        break;
    default:
        break;
    }

    if ((semantics & gl_SemanticsAcquire) && 
        (callNode.getOp() == EOpAtomicStore || callNode.getOp() == EOpImageAtomicStore)) {
        error(loc, "gl_SemanticsAcquire must not be used with (image) atomic store",
              fnCandidate.getName().c_str(), "");
    }
    if ((semantics & gl_SemanticsRelease) && 
        (callNode.getOp() == EOpAtomicLoad || callNode.getOp() == EOpImageAtomicLoad)) {
        error(loc, "gl_SemanticsRelease must not be used with (image) atomic load",
              fnCandidate.getName().c_str(), "");
    }
    if ((semantics & gl_SemanticsAcquireRelease) && 
        (callNode.getOp() == EOpAtomicStore || callNode.getOp() == EOpImageAtomicStore || 
         callNode.getOp() == EOpAtomicLoad  || callNode.getOp() == EOpImageAtomicLoad)) {
        error(loc, "gl_SemanticsAcquireRelease must not be used with (image) atomic load/store",
              fnCandidate.getName().c_str(), "");
    }
    if (((semantics | semantics2) & ~(gl_SemanticsAcquire |
                                      gl_SemanticsRelease |
                                      gl_SemanticsAcquireRelease |
                                      gl_SemanticsMakeAvailable |
                                      gl_SemanticsMakeVisible |
                                      gl_SemanticsVolatile))) {
        error(loc, "Invalid semantics value", fnCandidate.getName().c_str(), "");
    }
    if (((storageClassSemantics | storageClassSemantics2) & ~(gl_StorageSemanticsBuffer |
                                                              gl_StorageSemanticsShared |
                                                              gl_StorageSemanticsImage |
                                                              gl_StorageSemanticsOutput))) {
        error(loc, "Invalid storage class semantics value", fnCandidate.getName().c_str(), "");
    }

    if (callNode.getOp() == EOpMemoryBarrier) {
        if (!IsPow2(semantics & (gl_SemanticsAcquire | gl_SemanticsRelease | gl_SemanticsAcquireRelease))) {
            error(loc, "Semantics must include exactly one of gl_SemanticsRelease, gl_SemanticsAcquire, or "
                       "gl_SemanticsAcquireRelease", fnCandidate.getName().c_str(), "");
        }
    } else {
        if (semantics & (gl_SemanticsAcquire | gl_SemanticsRelease | gl_SemanticsAcquireRelease)) {
            if (!IsPow2(semantics & (gl_SemanticsAcquire | gl_SemanticsRelease | gl_SemanticsAcquireRelease))) {
                error(loc, "Semantics must not include multiple of gl_SemanticsRelease, gl_SemanticsAcquire, or "
                           "gl_SemanticsAcquireRelease", fnCandidate.getName().c_str(), "");
            }
        }
        if (semantics2 & (gl_SemanticsAcquire | gl_SemanticsRelease | gl_SemanticsAcquireRelease)) {
            if (!IsPow2(semantics2 & (gl_SemanticsAcquire | gl_SemanticsRelease | gl_SemanticsAcquireRelease))) {
                error(loc, "semUnequal must not include multiple of gl_SemanticsRelease, gl_SemanticsAcquire, or "
                           "gl_SemanticsAcquireRelease", fnCandidate.getName().c_str(), "");
            }
        }
    }
    if (callNode.getOp() == EOpMemoryBarrier) {
        if (storageClassSemantics == 0) {
            error(loc, "Storage class semantics must not be zero", fnCandidate.getName().c_str(), "");
        }
    }
    if (callNode.getOp() == EOpBarrier && semantics != 0 && storageClassSemantics == 0) {
        error(loc, "Storage class semantics must not be zero", fnCandidate.getName().c_str(), "");
    }
    if ((callNode.getOp() == EOpAtomicCompSwap || callNode.getOp() == EOpImageAtomicCompSwap) &&
        (semantics2 & (gl_SemanticsRelease | gl_SemanticsAcquireRelease))) {
        error(loc, "semUnequal must not be gl_SemanticsRelease or gl_SemanticsAcquireRelease",
              fnCandidate.getName().c_str(), "");
    }
    if ((semantics & gl_SemanticsMakeAvailable) &&
        !(semantics & (gl_SemanticsRelease | gl_SemanticsAcquireRelease))) {
        error(loc, "gl_SemanticsMakeAvailable requires gl_SemanticsRelease or gl_SemanticsAcquireRelease",
              fnCandidate.getName().c_str(), "");
    }
    if ((semantics & gl_SemanticsMakeVisible) &&
        !(semantics & (gl_SemanticsAcquire | gl_SemanticsAcquireRelease))) {
        error(loc, "gl_SemanticsMakeVisible requires gl_SemanticsAcquire or gl_SemanticsAcquireRelease",
              fnCandidate.getName().c_str(), "");
    }
    if ((semantics & gl_SemanticsVolatile) &&
        (callNode.getOp() == EOpMemoryBarrier || callNode.getOp() == EOpBarrier)) {
        error(loc, "gl_SemanticsVolatile must not be used with memoryBarrier or controlBarrier",
              fnCandidate.getName().c_str(), "");
    }
    if ((callNode.getOp() == EOpAtomicCompSwap || callNode.getOp() == EOpImageAtomicCompSwap) &&
        ((semantics ^ semantics2) & gl_SemanticsVolatile)) {
        error(loc, "semEqual and semUnequal must either both include gl_SemanticsVolatile or neither",
              fnCandidate.getName().c_str(), "");
    }
}

//
// Do additional checking of built-in function calls that is not caught
// by normal semantic checks on argument type, extension tagging, etc.
//
// Assumes there has been a semantically correct match to a built-in function prototype.
//
void TParseContext::builtInOpCheck(const TSourceLoc& loc, const TFunction& fnCandidate, TIntermOperator& callNode)
{
    // Set up convenience accessors to the argument(s).  There is almost always
    // multiple arguments for the cases below, but when there might be one,
    // check the unaryArg first.
    const TIntermSequence* argp = nullptr;   // confusing to use [] syntax on a pointer, so this is to help get a reference
    const TIntermTyped* unaryArg = nullptr;
    const TIntermTyped* arg0 = nullptr;
    if (callNode.getAsAggregate()) {
        argp = &callNode.getAsAggregate()->getSequence();
        if (argp->size() > 0)
            arg0 = (*argp)[0]->getAsTyped();
    } else {
        assert(callNode.getAsUnaryNode());
        unaryArg = callNode.getAsUnaryNode()->getOperand();
        arg0 = unaryArg;
    }

    TString featureString;
    const char* feature = nullptr;
    switch (callNode.getOp()) {
#ifndef GLSLANG_WEB
    case EOpTextureGather:
    case EOpTextureGatherOffset:
    case EOpTextureGatherOffsets:
    {
        // Figure out which variants are allowed by what extensions,
        // and what arguments must be constant for which situations.

        featureString = fnCandidate.getName();
        featureString += "(...)";
        feature = featureString.c_str();
        profileRequires(loc, EEsProfile, 310, nullptr, feature);
        int compArg = -1;  // track which argument, if any, is the constant component argument
        switch (callNode.getOp()) {
        case EOpTextureGather:
            // More than two arguments needs gpu_shader5, and rectangular or shadow needs gpu_shader5,
            // otherwise, need GL_ARB_texture_gather.
            if (fnCandidate.getParamCount() > 2 || fnCandidate[0].type->getSampler().dim == EsdRect || fnCandidate[0].type->getSampler().shadow) {
                profileRequires(loc, ~EEsProfile, 400, E_GL_ARB_gpu_shader5, feature);
                if (! fnCandidate[0].type->getSampler().shadow)
                    compArg = 2;
            } else
                profileRequires(loc, ~EEsProfile, 400, E_GL_ARB_texture_gather, feature);
            break;
        case EOpTextureGatherOffset:
            // GL_ARB_texture_gather is good enough for 2D non-shadow textures with no component argument
            if (fnCandidate[0].type->getSampler().dim == Esd2D && ! fnCandidate[0].type->getSampler().shadow && fnCandidate.getParamCount() == 3)
                profileRequires(loc, ~EEsProfile, 400, E_GL_ARB_texture_gather, feature);
            else
                profileRequires(loc, ~EEsProfile, 400, E_GL_ARB_gpu_shader5, feature);
            if (! (*argp)[fnCandidate[0].type->getSampler().shadow ? 3 : 2]->getAsConstantUnion())
                profileRequires(loc, EEsProfile, 320, Num_AEP_gpu_shader5, AEP_gpu_shader5,
                                "non-constant offset argument");
            if (! fnCandidate[0].type->getSampler().shadow)
                compArg = 3;
            break;
        case EOpTextureGatherOffsets:
            profileRequires(loc, ~EEsProfile, 400, E_GL_ARB_gpu_shader5, feature);
            if (! fnCandidate[0].type->getSampler().shadow)
                compArg = 3;
            // check for constant offsets
            if (! (*argp)[fnCandidate[0].type->getSampler().shadow ? 3 : 2]->getAsConstantUnion())
                error(loc, "must be a compile-time constant:", feature, "offsets argument");
            break;
        default:
            break;
        }

        if (compArg > 0 && compArg < fnCandidate.getParamCount()) {
            if ((*argp)[compArg]->getAsConstantUnion()) {
                int value = (*argp)[compArg]->getAsConstantUnion()->getConstArray()[0].getIConst();
                if (value < 0 || value > 3)
                    error(loc, "must be 0, 1, 2, or 3:", feature, "component argument");
            } else
                error(loc, "must be a compile-time constant:", feature, "component argument");
        }

        bool bias = false;
        if (callNode.getOp() == EOpTextureGather)
            bias = fnCandidate.getParamCount() > 3;
        else if (callNode.getOp() == EOpTextureGatherOffset ||
                 callNode.getOp() == EOpTextureGatherOffsets)
            bias = fnCandidate.getParamCount() > 4;

        if (bias) {
            featureString = fnCandidate.getName();
            featureString += "with bias argument";
            feature = featureString.c_str();
            profileRequires(loc, ~EEsProfile, 450, nullptr, feature);
            requireExtensions(loc, 1, &E_GL_AMD_texture_gather_bias_lod, feature);
        }
        break;
    }
    case EOpSparseTextureGather:
    case EOpSparseTextureGatherOffset:
    case EOpSparseTextureGatherOffsets:
    {
        bool bias = false;
        if (callNode.getOp() == EOpSparseTextureGather)
            bias = fnCandidate.getParamCount() > 4;
        else if (callNode.getOp() == EOpSparseTextureGatherOffset ||
                 callNode.getOp() == EOpSparseTextureGatherOffsets)
            bias = fnCandidate.getParamCount() > 5;

        if (bias) {
            featureString = fnCandidate.getName();
            featureString += "with bias argument";
            feature = featureString.c_str();
            profileRequires(loc, ~EEsProfile, 450, nullptr, feature);
            requireExtensions(loc, 1, &E_GL_AMD_texture_gather_bias_lod, feature);
        }

        break;
    }

    case EOpSparseTextureGatherLod:
    case EOpSparseTextureGatherLodOffset:
    case EOpSparseTextureGatherLodOffsets:
    {
        requireExtensions(loc, 1, &E_GL_ARB_sparse_texture2, fnCandidate.getName().c_str());
        break;
    }

    case EOpSwizzleInvocations:
    {
        if (! (*argp)[1]->getAsConstantUnion())
            error(loc, "argument must be compile-time constant", "offset", "");
        else {
            unsigned offset[4] = {};
            offset[0] = (*argp)[1]->getAsConstantUnion()->getConstArray()[0].getUConst();
            offset[1] = (*argp)[1]->getAsConstantUnion()->getConstArray()[1].getUConst();
            offset[2] = (*argp)[1]->getAsConstantUnion()->getConstArray()[2].getUConst();
            offset[3] = (*argp)[1]->getAsConstantUnion()->getConstArray()[3].getUConst();
            if (offset[0] > 3 || offset[1] > 3 || offset[2] > 3 || offset[3] > 3)
                error(loc, "components must be in the range [0, 3]", "offset", "");
        }

        break;
    }

    case EOpSwizzleInvocationsMasked:
    {
        if (! (*argp)[1]->getAsConstantUnion())
            error(loc, "argument must be compile-time constant", "mask", "");
        else {
            unsigned mask[3] = {};
            mask[0] = (*argp)[1]->getAsConstantUnion()->getConstArray()[0].getUConst();
            mask[1] = (*argp)[1]->getAsConstantUnion()->getConstArray()[1].getUConst();
            mask[2] = (*argp)[1]->getAsConstantUnion()->getConstArray()[2].getUConst();
            if (mask[0] > 31 || mask[1] > 31 || mask[2] > 31)
                error(loc, "components must be in the range [0, 31]", "mask", "");
        }

        break;
    }
#endif

    case EOpTextureOffset:
    case EOpTextureFetchOffset:
    case EOpTextureProjOffset:
    case EOpTextureLodOffset:
    case EOpTextureProjLodOffset:
    case EOpTextureGradOffset:
    case EOpTextureProjGradOffset:
    {
        // Handle texture-offset limits checking
        // Pick which argument has to hold constant offsets
        int arg = -1;
        switch (callNode.getOp()) {
        case EOpTextureOffset:          arg = 2;  break;
        case EOpTextureFetchOffset:     arg = (arg0->getType().getSampler().isRect()) ? 2 : 3; break;
        case EOpTextureProjOffset:      arg = 2;  break;
        case EOpTextureLodOffset:       arg = 3;  break;
        case EOpTextureProjLodOffset:   arg = 3;  break;
        case EOpTextureGradOffset:      arg = 4;  break;
        case EOpTextureProjGradOffset:  arg = 4;  break;
        default:
            assert(0);
            break;
        }

        if (arg > 0) {

#ifndef GLSLANG_WEB
            bool f16ShadowCompare = (*argp)[1]->getAsTyped()->getBasicType() == EbtFloat16 && arg0->getType().getSampler().shadow;
            if (f16ShadowCompare)
                ++arg;
#endif
            if (! (*argp)[arg]->getAsConstantUnion())
                error(loc, "argument must be compile-time constant", "texel offset", "");
            else {
                const TType& type = (*argp)[arg]->getAsTyped()->getType();
                for (int c = 0; c < type.getVectorSize(); ++c) {
                    int offset = (*argp)[arg]->getAsConstantUnion()->getConstArray()[c].getIConst();
                    if (offset > resources.maxProgramTexelOffset || offset < resources.minProgramTexelOffset)
                        error(loc, "value is out of range:", "texel offset", "[gl_MinProgramTexelOffset, gl_MaxProgramTexelOffset]");
                }
            }
        }

        break;
    }

#ifndef GLSLANG_WEB
    case EOpTraceNV:
        if (!(*argp)[10]->getAsConstantUnion())
            error(loc, "argument must be compile-time constant", "payload number", "");
        break;
    case EOpExecuteCallableNV:
        if (!(*argp)[1]->getAsConstantUnion())
            error(loc, "argument must be compile-time constant", "callable data number", "");
        break;

    case EOpTextureQuerySamples:
    case EOpImageQuerySamples:
        // GL_ARB_shader_texture_image_samples
        profileRequires(loc, ~EEsProfile, 450, E_GL_ARB_shader_texture_image_samples, "textureSamples and imageSamples");
        break;

    case EOpImageAtomicAdd:
    case EOpImageAtomicMin:
    case EOpImageAtomicMax:
    case EOpImageAtomicAnd:
    case EOpImageAtomicOr:
    case EOpImageAtomicXor:
    case EOpImageAtomicExchange:
    case EOpImageAtomicCompSwap:
    case EOpImageAtomicLoad:
    case EOpImageAtomicStore:
    {
        // Make sure the image types have the correct layout() format and correct argument types
        const TType& imageType = arg0->getType();
        if (imageType.getSampler().type == EbtInt || imageType.getSampler().type == EbtUint) {
            if (imageType.getQualifier().getFormat() != ElfR32i && imageType.getQualifier().getFormat() != ElfR32ui)
                error(loc, "only supported on image with format r32i or r32ui", fnCandidate.getName().c_str(), "");
        } else {
            if (fnCandidate.getName().compare(0, 19, "imageAtomicExchange") != 0)
                error(loc, "only supported on integer images", fnCandidate.getName().c_str(), "");
            else if (imageType.getQualifier().getFormat() != ElfR32f && isEsProfile())
                error(loc, "only supported on image with format r32f", fnCandidate.getName().c_str(), "");
        }

        const size_t maxArgs = imageType.getSampler().isMultiSample() ? 5 : 4;
        if (argp->size() > maxArgs) {
            requireExtensions(loc, 1, &E_GL_KHR_memory_scope_semantics, fnCandidate.getName().c_str());
            memorySemanticsCheck(loc, fnCandidate, callNode);
        }

        break;
    }

    case EOpAtomicAdd:
    case EOpAtomicMin:
    case EOpAtomicMax:
    case EOpAtomicAnd:
    case EOpAtomicOr:
    case EOpAtomicXor:
    case EOpAtomicExchange:
    case EOpAtomicCompSwap:
    case EOpAtomicLoad:
    case EOpAtomicStore:
    {
        if (argp->size() > 3) {
            requireExtensions(loc, 1, &E_GL_KHR_memory_scope_semantics, fnCandidate.getName().c_str());
            memorySemanticsCheck(loc, fnCandidate, callNode);
        } else if (arg0->getType().getBasicType() == EbtInt64 || arg0->getType().getBasicType() == EbtUint64) {
            const char* const extensions[2] = { E_GL_NV_shader_atomic_int64,
                                                E_GL_EXT_shader_atomic_int64 };
            requireExtensions(loc, 2, extensions, fnCandidate.getName().c_str());
        }
        break;
    }

    case EOpInterpolateAtCentroid:
    case EOpInterpolateAtSample:
    case EOpInterpolateAtOffset:
    case EOpInterpolateAtVertex:
        // Make sure the first argument is an interpolant, or an array element of an interpolant
        if (arg0->getType().getQualifier().storage != EvqVaryingIn) {
            // It might still be an array element.
            //
            // We could check more, but the semantics of the first argument are already met; the
            // only way to turn an array into a float/vec* is array dereference and swizzle.
            //
            // ES and desktop 4.3 and earlier:  swizzles may not be used
            // desktop 4.4 and later: swizzles may be used
            bool swizzleOkay = (!isEsProfile()) && (version >= 440);
            const TIntermTyped* base = TIntermediate::findLValueBase(arg0, swizzleOkay);
            if (base == nullptr || base->getType().getQualifier().storage != EvqVaryingIn)
                error(loc, "first argument must be an interpolant, or interpolant-array element", fnCandidate.getName().c_str(), "");
        }

        if (callNode.getOp() == EOpInterpolateAtVertex) {
            if (!arg0->getType().getQualifier().isExplicitInterpolation())
                error(loc, "argument must be qualified as __explicitInterpAMD in", "interpolant", "");
            else {
                if (! (*argp)[1]->getAsConstantUnion())
                    error(loc, "argument must be compile-time constant", "vertex index", "");
                else {
                    unsigned vertexIdx = (*argp)[1]->getAsConstantUnion()->getConstArray()[0].getUConst();
                    if (vertexIdx > 2)
                        error(loc, "must be in the range [0, 2]", "vertex index", "");
                }
            }
        }
        break;

    case EOpEmitStreamVertex:
    case EOpEndStreamPrimitive:
        intermediate.setMultiStream();
        break;

    case EOpSubgroupClusteredAdd:
    case EOpSubgroupClusteredMul:
    case EOpSubgroupClusteredMin:
    case EOpSubgroupClusteredMax:
    case EOpSubgroupClusteredAnd:
    case EOpSubgroupClusteredOr:
    case EOpSubgroupClusteredXor:
        // The <clusterSize> as used in the subgroupClustered<op>() operations must be:
        // - An integral constant expression.
        // - At least 1.
        // - A power of 2.
        if ((*argp)[1]->getAsConstantUnion() == nullptr)
            error(loc, "argument must be compile-time constant", "cluster size", "");
        else {
            int size = (*argp)[1]->getAsConstantUnion()->getConstArray()[0].getIConst();
            if (size < 1)
                error(loc, "argument must be at least 1", "cluster size", "");
            else if (!IsPow2(size))
                error(loc, "argument must be a power of 2", "cluster size", "");
        }
        break;

    case EOpSubgroupBroadcast:
        if (spvVersion.spv < EShTargetSpv_1_5) {
            // <id> must be an integral constant expression.
            if ((*argp)[1]->getAsConstantUnion() == nullptr)
                error(loc, "argument must be compile-time constant", "id", "");
        }
        break;

    case EOpBarrier:
    case EOpMemoryBarrier:
        if (argp->size() > 0) {
            requireExtensions(loc, 1, &E_GL_KHR_memory_scope_semantics, fnCandidate.getName().c_str());
            memorySemanticsCheck(loc, fnCandidate, callNode);
        }
        break;
#endif

    default:
        break;
    }

    // Texture operations on texture objects (aside from texelFetch on a
    // textureBuffer) require EXT_samplerless_texture_functions.
    switch (callNode.getOp()) {
    case EOpTextureQuerySize:
    case EOpTextureQueryLevels:
    case EOpTextureQuerySamples:
    case EOpTextureFetch:
    case EOpTextureFetchOffset:
    {
        const TSampler& sampler = fnCandidate[0].type->getSampler();

        const bool isTexture = sampler.isTexture() && !sampler.isCombined();
        const bool isBuffer = sampler.isBuffer();
        const bool isFetch = callNode.getOp() == EOpTextureFetch || callNode.getOp() == EOpTextureFetchOffset;

        if (isTexture && (!isBuffer || !isFetch))
            requireExtensions(loc, 1, &E_GL_EXT_samplerless_texture_functions, fnCandidate.getName().c_str());

        break;
    }

    default:
        break;
    }

    if (callNode.getOp() > EOpSubgroupGuardStart && callNode.getOp() < EOpSubgroupGuardStop) {
        // these require SPIR-V 1.3
        if (spvVersion.spv > 0 && spvVersion.spv < EShTargetSpv_1_3)
            error(loc, "requires SPIR-V 1.3", "subgroup op", "");

        // Check that if extended types are being used that the correct extensions are enabled.
        if (arg0 != nullptr) {
            const TType& type = arg0->getType();
            switch (type.getBasicType()) {
            default:
                break;
            case EbtInt8:
            case EbtUint8:
                requireExtensions(loc, 1, &E_GL_EXT_shader_subgroup_extended_types_int8, type.getCompleteString().c_str());
                break;
            case EbtInt16:
            case EbtUint16:
                requireExtensions(loc, 1, &E_GL_EXT_shader_subgroup_extended_types_int16, type.getCompleteString().c_str());
                break;
            case EbtInt64:
            case EbtUint64:
                requireExtensions(loc, 1, &E_GL_EXT_shader_subgroup_extended_types_int64, type.getCompleteString().c_str());
                break;
            case EbtFloat16:
                requireExtensions(loc, 1, &E_GL_EXT_shader_subgroup_extended_types_float16, type.getCompleteString().c_str());
                break;
            }
        }
    }
}

#ifndef GLSLANG_WEB

extern bool PureOperatorBuiltins;

// Deprecated!  Use PureOperatorBuiltins == true instead, in which case this
// functionality is handled in builtInOpCheck() instead of here.
//
// Do additional checking of built-in function calls that were not mapped
// to built-in operations (e.g., texturing functions).
//
// Assumes there has been a semantically correct match to a built-in function.
//
void TParseContext::nonOpBuiltInCheck(const TSourceLoc& loc, const TFunction& fnCandidate, TIntermAggregate& callNode)
{
    // Further maintenance of this function is deprecated, because the "correct"
    // future-oriented design is to not have to do string compares on function names.

    // If PureOperatorBuiltins == true, then all built-ins should be mapped
    // to a TOperator, and this function would then never get called.

    assert(PureOperatorBuiltins == false);

    // built-in texturing functions get their return value precision from the precision of the sampler
    if (fnCandidate.getType().getQualifier().precision == EpqNone &&
        fnCandidate.getParamCount() > 0 && fnCandidate[0].type->getBasicType() == EbtSampler)
        callNode.getQualifier().precision = callNode.getSequence()[0]->getAsTyped()->getQualifier().precision;

    if (fnCandidate.getName().compare(0, 7, "texture") == 0) {
        if (fnCandidate.getName().compare(0, 13, "textureGather") == 0) {
            TString featureString = fnCandidate.getName() + "(...)";
            const char* feature = featureString.c_str();
            profileRequires(loc, EEsProfile, 310, nullptr, feature);

            int compArg = -1;  // track which argument, if any, is the constant component argument
            if (fnCandidate.getName().compare("textureGatherOffset") == 0) {
                // GL_ARB_texture_gather is good enough for 2D non-shadow textures with no component argument
                if (fnCandidate[0].type->getSampler().dim == Esd2D && ! fnCandidate[0].type->getSampler().shadow && fnCandidate.getParamCount() == 3)
                    profileRequires(loc, ~EEsProfile, 400, E_GL_ARB_texture_gather, feature);
                else
                    profileRequires(loc, ~EEsProfile, 400, E_GL_ARB_gpu_shader5, feature);
                int offsetArg = fnCandidate[0].type->getSampler().shadow ? 3 : 2;
                if (! callNode.getSequence()[offsetArg]->getAsConstantUnion())
                    profileRequires(loc, EEsProfile, 320, Num_AEP_gpu_shader5, AEP_gpu_shader5,
                                    "non-constant offset argument");
                if (! fnCandidate[0].type->getSampler().shadow)
                    compArg = 3;
            } else if (fnCandidate.getName().compare("textureGatherOffsets") == 0) {
                profileRequires(loc, ~EEsProfile, 400, E_GL_ARB_gpu_shader5, feature);
                if (! fnCandidate[0].type->getSampler().shadow)
                    compArg = 3;
                // check for constant offsets
                int offsetArg = fnCandidate[0].type->getSampler().shadow ? 3 : 2;
                if (! callNode.getSequence()[offsetArg]->getAsConstantUnion())
                    error(loc, "must be a compile-time constant:", feature, "offsets argument");
            } else if (fnCandidate.getName().compare("textureGather") == 0) {
                // More than two arguments needs gpu_shader5, and rectangular or shadow needs gpu_shader5,
                // otherwise, need GL_ARB_texture_gather.
                if (fnCandidate.getParamCount() > 2 || fnCandidate[0].type->getSampler().dim == EsdRect || fnCandidate[0].type->getSampler().shadow) {
                    profileRequires(loc, ~EEsProfile, 400, E_GL_ARB_gpu_shader5, feature);
                    if (! fnCandidate[0].type->getSampler().shadow)
                        compArg = 2;
                } else
                    profileRequires(loc, ~EEsProfile, 400, E_GL_ARB_texture_gather, feature);
            }

            if (compArg > 0 && compArg < fnCandidate.getParamCount()) {
                if (callNode.getSequence()[compArg]->getAsConstantUnion()) {
                    int value = callNode.getSequence()[compArg]->getAsConstantUnion()->getConstArray()[0].getIConst();
                    if (value < 0 || value > 3)
                        error(loc, "must be 0, 1, 2, or 3:", feature, "component argument");
                } else
                    error(loc, "must be a compile-time constant:", feature, "component argument");
            }
        } else {
            // this is only for functions not starting "textureGather"...
            if (fnCandidate.getName().find("Offset") != TString::npos) {

                // Handle texture-offset limits checking
                int arg = -1;
                if (fnCandidate.getName().compare("textureOffset") == 0)
                    arg = 2;
                else if (fnCandidate.getName().compare("texelFetchOffset") == 0)
                    arg = 3;
                else if (fnCandidate.getName().compare("textureProjOffset") == 0)
                    arg = 2;
                else if (fnCandidate.getName().compare("textureLodOffset") == 0)
                    arg = 3;
                else if (fnCandidate.getName().compare("textureProjLodOffset") == 0)
                    arg = 3;
                else if (fnCandidate.getName().compare("textureGradOffset") == 0)
                    arg = 4;
                else if (fnCandidate.getName().compare("textureProjGradOffset") == 0)
                    arg = 4;

                if (arg > 0) {
                    if (! callNode.getSequence()[arg]->getAsConstantUnion())
                        error(loc, "argument must be compile-time constant", "texel offset", "");
                    else {
                        const TType& type = callNode.getSequence()[arg]->getAsTyped()->getType();
                        for (int c = 0; c < type.getVectorSize(); ++c) {
                            int offset = callNode.getSequence()[arg]->getAsConstantUnion()->getConstArray()[c].getIConst();
                            if (offset > resources.maxProgramTexelOffset || offset < resources.minProgramTexelOffset)
                                error(loc, "value is out of range:", "texel offset", "[gl_MinProgramTexelOffset, gl_MaxProgramTexelOffset]");
                        }
                    }
                }
            }
        }
    }

    // GL_ARB_shader_texture_image_samples
    if (fnCandidate.getName().compare(0, 14, "textureSamples") == 0 || fnCandidate.getName().compare(0, 12, "imageSamples") == 0)
        profileRequires(loc, ~EEsProfile, 450, E_GL_ARB_shader_texture_image_samples, "textureSamples and imageSamples");

    if (fnCandidate.getName().compare(0, 11, "imageAtomic") == 0) {
        const TType& imageType = callNode.getSequence()[0]->getAsTyped()->getType();
        if (imageType.getSampler().type == EbtInt || imageType.getSampler().type == EbtUint) {
            if (imageType.getQualifier().getFormat() != ElfR32i && imageType.getQualifier().getFormat() != ElfR32ui)
                error(loc, "only supported on image with format r32i or r32ui", fnCandidate.getName().c_str(), "");
        } else {
            if (fnCandidate.getName().compare(0, 19, "imageAtomicExchange") != 0)
                error(loc, "only supported on integer images", fnCandidate.getName().c_str(), "");
            else if (imageType.getQualifier().getFormat() != ElfR32f && isEsProfile())
                error(loc, "only supported on image with format r32f", fnCandidate.getName().c_str(), "");
        }
    }
}

#endif

//
// Do any extra checking for a user function call.
//
void TParseContext::userFunctionCallCheck(const TSourceLoc& loc, TIntermAggregate& callNode)
{
    TIntermSequence& arguments = callNode.getSequence();

    for (int i = 0; i < (int)arguments.size(); ++i)
        samplerConstructorLocationCheck(loc, "call argument", arguments[i]);
}

//
// Emit an error if this is a sampler constructor
//
void TParseContext::samplerConstructorLocationCheck(const TSourceLoc& loc, const char* token, TIntermNode* node)
{
    if (node->getAsOperator() && node->getAsOperator()->getOp() == EOpConstructTextureSampler)
        error(loc, "sampler constructor must appear at point of use", token, "");
}

//
// Handle seeing a built-in constructor in a grammar production.
//
TFunction* TParseContext::handleConstructorCall(const TSourceLoc& loc, const TPublicType& publicType)
{
    TType type(publicType);
    type.getQualifier().precision = EpqNone;

    if (type.isArray()) {
        profileRequires(loc, ENoProfile, 120, E_GL_3DL_array_objects, "arrayed constructor");
        profileRequires(loc, EEsProfile, 300, nullptr, "arrayed constructor");
    }

    TOperator op = intermediate.mapTypeToConstructorOp(type);

    if (op == EOpNull) {
        error(loc, "cannot construct this type", type.getBasicString(), "");
        op = EOpConstructFloat;
        TType errorType(EbtFloat);
        type.shallowCopy(errorType);
    }

    TString empty("");

    return new TFunction(&empty, type, op);
}

// Handle seeing a precision qualifier in the grammar.
void TParseContext::handlePrecisionQualifier(const TSourceLoc& /*loc*/, TQualifier& qualifier, TPrecisionQualifier precision)
{
    if (obeyPrecisionQualifiers())
        qualifier.precision = precision;
}

// Check for messages to give on seeing a precision qualifier used in a
// declaration in the grammar.
void TParseContext::checkPrecisionQualifier(const TSourceLoc& loc, TPrecisionQualifier)
{
    if (precisionManager.shouldWarnAboutDefaults()) {
        warn(loc, "all default precisions are highp; use precision statements to quiet warning, e.g.:\n"
                  "         \"precision mediump int; precision highp float;\"", "", "");
        precisionManager.defaultWarningGiven();
    }
}

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

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

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

//
// A basic type of EbtVoid is a key that the name string was seen in the source, but
// it was not found as a variable in the symbol table.  If so, give the error
// message and insert a dummy variable in the symbol table to prevent future errors.
//
void TParseContext::variableCheck(TIntermTyped*& nodePtr)
{
    TIntermSymbol* symbol = nodePtr->getAsSymbolNode();
    if (! symbol)
        return;

    if (symbol->getType().getBasicType() == EbtVoid) {
        const char *extraInfoFormat = "";
        if (spvVersion.vulkan != 0 && symbol->getName() == "gl_VertexID") {
          extraInfoFormat = "(Did you mean gl_VertexIndex?)";
        } else if (spvVersion.vulkan != 0 && symbol->getName() == "gl_InstanceID") {
          extraInfoFormat = "(Did you mean gl_InstanceIndex?)";
        }
        error(symbol->getLoc(), "undeclared identifier", symbol->getName().c_str(), extraInfoFormat);

        // Add to symbol table to prevent future error messages on the same name
        if (symbol->getName().size() > 0) {
            TVariable* fakeVariable = new TVariable(&symbol->getName(), TType(EbtFloat));
            symbolTable.insert(*fakeVariable);

            // substitute a symbol node for this new variable
            nodePtr = intermediate.addSymbol(*fakeVariable, symbol->getLoc());
        }
    } else {
        switch (symbol->getQualifier().storage) {
        case EvqPointCoord:
            profileRequires(symbol->getLoc(), ENoProfile, 120, nullptr, "gl_PointCoord");
            break;
        default: break; // some compilers want this
        }
    }
}

//
// 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.
//
// Returns true if there was an error.
//
bool TParseContext::lValueErrorCheck(const TSourceLoc& loc, const char* op, TIntermTyped* node)
{
    TIntermBinary* binaryNode = node->getAsBinaryNode();

    if (binaryNode) {
        bool errorReturn = false;

        switch(binaryNode->getOp()) {
#ifndef GLSLANG_WEB
        case EOpIndexDirect:
        case EOpIndexIndirect:
            // ...  tessellation control shader ...
            // If a per-vertex output variable is used as an l-value, it is a
            // compile-time or link-time error if the expression indicating the
            // vertex index is not the identifier gl_InvocationID.
            if (language == EShLangTessControl) {
                const TType& leftType = binaryNode->getLeft()->getType();
                if (leftType.getQualifier().storage == EvqVaryingOut && ! leftType.getQualifier().patch && binaryNode->getLeft()->getAsSymbolNode()) {
                    // we have a per-vertex output
                    const TIntermSymbol* rightSymbol = binaryNode->getRight()->getAsSymbolNode();
                    if (! rightSymbol || rightSymbol->getQualifier().builtIn != EbvInvocationId)
                        error(loc, "tessellation-control per-vertex output l-value must be indexed with gl_InvocationID", "[]", "");
                }
            }
            break; // left node is checked by base class
#endif
        case EOpVectorSwizzle:
            errorReturn = lValueErrorCheck(loc, op, binaryNode->getLeft());
            if (!errorReturn)