#include "../../slang.h"

#include "../core/slang-io.h"
#include "../core/slang-string-util.h"
#include "../core/slang-shared-library.h"
#include "../core/slang-archive-file-system.h"
#include "../core/slang-type-text-util.h"
#include "../core/slang-type-convert-util.h"

#include "slang-check.h"
#include "slang-parameter-binding.h"
#include "slang-lower-to-ir.h"
#include "slang-mangle.h"
#include "slang-parser.h"
#include "slang-preprocessor.h"

#include "slang-type-layout.h"

#include "slang-options.h"

#include "slang-repro.h"

#include "../core/slang-file-system.h"
#include "../core/slang-writer.h"

#include "../compiler-core/slang-source-loc.h"

#include "slang-ast-dump.h"

#include "slang-serialize-ast.h"
#include "slang-serialize-ir.h"
#include "slang-serialize-container.h"

#include "slang-doc-ast.h"
#include "slang-doc-markdown-writer.h"

#include "slang-check-impl.h"

#include "../../slang-tag-version.h"

// Used to print exception type names in internal-compiler-error messages
#include <typeinfo>

#ifdef _WIN32
#define WIN32_LEAN_AND_MEAN
#define NOMINMAX
#include <Windows.h>
#undef WIN32_LEAN_AND_MEAN
#undef NOMINMAX
#endif

extern Slang::String get_slang_cuda_prelude();
extern Slang::String get_slang_cpp_prelude();
extern Slang::String get_slang_hlsl_prelude();

namespace Slang {

/* static */const BaseTypeInfo BaseTypeInfo::s_info[Index(BaseType::CountOf)] = 
{
    { 0, 0, uint8_t(BaseType::Void) },
    { uint8_t(sizeof(bool)),   0, uint8_t(BaseType::Bool) },
    { uint8_t(sizeof(int8_t)),   BaseTypeInfo::Flag::Signed | BaseTypeInfo::Flag::Integer , uint8_t(BaseType::Int8) },
    { uint8_t(sizeof(int16_t)),  BaseTypeInfo::Flag::Signed | BaseTypeInfo::Flag::Integer , uint8_t(BaseType::Int16) },
    { uint8_t(sizeof(int32_t)),  BaseTypeInfo::Flag::Signed | BaseTypeInfo::Flag::Integer , uint8_t(BaseType::Int) },
    { uint8_t(sizeof(int64_t)),  BaseTypeInfo::Flag::Signed | BaseTypeInfo::Flag::Integer , uint8_t(BaseType::Int64) },
    { uint8_t(sizeof(uint8_t)),                               BaseTypeInfo::Flag::Integer , uint8_t(BaseType::UInt8) },
    { uint8_t(sizeof(uint16_t)),                              BaseTypeInfo::Flag::Integer , uint8_t(BaseType::UInt16) },
    { uint8_t(sizeof(uint32_t)),                              BaseTypeInfo::Flag::Integer , uint8_t(BaseType::UInt) },
    { uint8_t(sizeof(uint64_t)),                              BaseTypeInfo::Flag::Integer, uint8_t(BaseType::UInt64) },
    { uint8_t(sizeof(uint16_t)), BaseTypeInfo::Flag::FloatingPoint , uint8_t(BaseType::Half) },
    { uint8_t(sizeof(float)),    BaseTypeInfo::Flag::FloatingPoint , uint8_t(BaseType::Float) },
    { uint8_t(sizeof(double)),   BaseTypeInfo::Flag::FloatingPoint , uint8_t(BaseType::Double) },
};

/* static */bool BaseTypeInfo::check()
{
    for (Index i = 0; i < SLANG_COUNT_OF(s_info); ++i)
    {
        if (s_info[i].baseType != i)
        {
            SLANG_ASSERT(!"Inconsistency between the s_info table and BaseInfo");
            return false;
        }
    }
    return true;
}

/* static */UnownedStringSlice BaseTypeInfo::asText(BaseType baseType)
{
    switch (baseType)
    {
        case BaseType::Void:            return UnownedStringSlice::fromLiteral("void");
        case BaseType::Bool:            return UnownedStringSlice::fromLiteral("bool");
        case BaseType::Int8:            return UnownedStringSlice::fromLiteral("int8_t");
        case BaseType::Int16:           return UnownedStringSlice::fromLiteral("int16_t");
        case BaseType::Int:             return UnownedStringSlice::fromLiteral("int");
        case BaseType::Int64:           return UnownedStringSlice::fromLiteral("int64_t");
        case BaseType::UInt8:           return UnownedStringSlice::fromLiteral("uint8_t");
        case BaseType::UInt16:          return UnownedStringSlice::fromLiteral("uint16_t");
        case BaseType::UInt:            return UnownedStringSlice::fromLiteral("uint");
        case BaseType::UInt64:          return UnownedStringSlice::fromLiteral("uint64_t");
        case BaseType::Half:            return UnownedStringSlice::fromLiteral("half");
        case BaseType::Float:           return UnownedStringSlice::fromLiteral("float");
        case BaseType::Double:          return UnownedStringSlice::fromLiteral("double");
        default:
        {
            SLANG_ASSERT(!"Unknown basic type");
            return UnownedStringSlice();
        }
    }
}

const char* getBuildTagString()
{
    return SLANG_TAG_VERSION;
}


void Session::init()
{
    SLANG_ASSERT(BaseTypeInfo::check());

    _initCodeGenTransitionMap();

    ::memset(m_downstreamCompilerLocators, 0, sizeof(m_downstreamCompilerLocators));
    DownstreamCompilerUtil::setDefaultLocators(m_downstreamCompilerLocators);
    m_downstreamCompilerSet = new DownstreamCompilerSet;

    // Initialize name pool
    getNamePool()->setRootNamePool(getRootNamePool());

    m_sharedLibraryLoader = DefaultSharedLibraryLoader::getSingleton();
    
    // Set up shared AST builder
    m_sharedASTBuilder = new SharedASTBuilder;
    m_sharedASTBuilder->init(this);

    //  Use to create a ASTBuilder
    RefPtr<ASTBuilder> builtinAstBuilder(new ASTBuilder(m_sharedASTBuilder, "m_builtInLinkage::m_astBuilder"));

    // And the global ASTBuilder
    globalAstBuilder = new ASTBuilder(m_sharedASTBuilder, "globalAstBuilder");

    // Make sure our source manager is initialized
    builtinSourceManager.initialize(nullptr, nullptr);

    // Built in linkage uses the built in builder
    m_builtinLinkage = new Linkage(this, builtinAstBuilder, nullptr);

    // Because the `Session` retains the builtin `Linkage`,
    // we need to make sure that the parent pointer inside
    // `Linkage` doesn't create a retain cycle.
    //
    // This operation ensures that the parent pointer will
    // just be a raw pointer, so that the builtin linkage
    // doesn't keep the parent session alive.
    //
    m_builtinLinkage->_stopRetainingParentSession();

    // Create scopes for various language builtins.
    //
    // TODO: load these on-demand to avoid parsing
    // stdlib code for languages the user won't use.

    baseLanguageScope = builtinAstBuilder->create<Scope>();

    // Will stay in scope as long as ASTBuilder
    baseModuleDecl = populateBaseLanguageModule(
        m_builtinLinkage->getASTBuilder(),
        baseLanguageScope);

    coreLanguageScope = builtinAstBuilder->create<Scope>();
    coreLanguageScope->nextSibling = baseLanguageScope;

    hlslLanguageScope = builtinAstBuilder->create<Scope>();
    hlslLanguageScope->nextSibling = coreLanguageScope;

    slangLanguageScope = builtinAstBuilder->create<Scope>();
    slangLanguageScope->nextSibling = hlslLanguageScope;

    {
        for (Index i = 0; i < Index(SourceLanguage::CountOf); ++i)
        {
            m_defaultDownstreamCompilers[i] = PassThroughMode::None;
        }
        m_defaultDownstreamCompilers[Index(SourceLanguage::C)] = PassThroughMode::GenericCCpp;
        m_defaultDownstreamCompilers[Index(SourceLanguage::CPP)] = PassThroughMode::GenericCCpp;
        m_defaultDownstreamCompilers[Index(SourceLanguage::CUDA)] = PassThroughMode::NVRTC;
    }

    // Set up default prelude code for target languages that need a prelude
    m_languagePreludes[Index(SourceLanguage::CUDA)] = get_slang_cuda_prelude();
    m_languagePreludes[Index(SourceLanguage::CPP)] = get_slang_cpp_prelude();
    m_languagePreludes[Index(SourceLanguage::HLSL)] = get_slang_hlsl_prelude();
}

void Session::_initCodeGenTransitionMap()
{
    // TODO(JS): Might want to do something about these in the future...

    //PassThroughMode getDownstreamCompilerRequiredForTarget(CodeGenTarget target);
    //SourceLanguage getDefaultSourceLanguageForDownstreamCompiler(PassThroughMode compiler);

    // Set up the default ways to do compilations between code gen targets
    auto& map = m_codeGenTransitionMap;
    
    // TODO(JS): There currently isn't a 'downstream compiler' for direct spirv output. If we did
    // it would presumably a transition from SlangIR to SPIRV.

    // For C and C++ we default to use the 'genericCCpp' compiler 
    {
        const CodeGenTarget sources[] = { CodeGenTarget::CSource, CodeGenTarget::CPPSource };
        for (auto source : sources)
        {
            // We *don't* add a default for host callable, as we will determine what is suitable depending on what
            // is available. We prefer LLVM if that's available. If it's not we can use generic C/C++ compiler

            map.addTransition(source, CodeGenTarget::SharedLibrary, PassThroughMode::GenericCCpp);
            map.addTransition(source, CodeGenTarget::Executable, PassThroughMode::GenericCCpp);
            map.addTransition(source, CodeGenTarget::ObjectCode, PassThroughMode::GenericCCpp);
        }
    }

    
    // Add all the straightforward transitions
    map.addTransition(CodeGenTarget::CUDASource, CodeGenTarget::PTX, PassThroughMode::NVRTC);
    map.addTransition(CodeGenTarget::HLSL, CodeGenTarget::DXBytecode, PassThroughMode::Fxc);
    map.addTransition(CodeGenTarget::HLSL, CodeGenTarget::DXIL, PassThroughMode::Dxc);
    map.addTransition(CodeGenTarget::GLSL, CodeGenTarget::SPIRV, PassThroughMode::Glslang);

    // To assembly
    map.addTransition(CodeGenTarget::SPIRV, CodeGenTarget::SPIRVAssembly, PassThroughMode::Glslang);
    map.addTransition(CodeGenTarget::DXIL, CodeGenTarget::DXILAssembly, PassThroughMode::Dxc);
    map.addTransition(CodeGenTarget::DXBytecode, CodeGenTarget::DXBytecodeAssembly, PassThroughMode::Fxc);
}

void Session::addBuiltins(
    char const*     sourcePath,
    char const*     sourceString)
{
    // TODO(tfoley): Add ability to directly new builtins to the appropriate scope
    addBuiltinSource(
        coreLanguageScope,
        sourcePath,
        sourceString);
}

void Session::setSharedLibraryLoader(ISlangSharedLibraryLoader* loader)
{
    // External API allows passing of nullptr to reset the loader
    loader = loader ? loader : DefaultSharedLibraryLoader::getSingleton();

    _setSharedLibraryLoader(loader);
}

ISlangSharedLibraryLoader* Session::getSharedLibraryLoader()
{
    return (m_sharedLibraryLoader == DefaultSharedLibraryLoader::getSingleton()) ? nullptr : m_sharedLibraryLoader.get();
}

SlangResult Session::checkCompileTargetSupport(SlangCompileTarget inTarget)
{
    auto target = CodeGenTarget(inTarget);

    const PassThroughMode mode = getDownstreamCompilerRequiredForTarget(target);
    return (mode != PassThroughMode::None) ?
        checkPassThroughSupport(SlangPassThrough(mode)) :
        SLANG_OK;
}

SlangResult Session::checkPassThroughSupport(SlangPassThrough inPassThrough)
{
    return checkExternalCompilerSupport(this, PassThroughMode(inPassThrough));
}

SlangResult Session::compileStdLib(slang::CompileStdLibFlags compileFlags)
{
    if (m_builtinLinkage->mapNameToLoadedModules.Count())
    {
        // Already have a StdLib loaded
        return SLANG_FAIL;
    }

    // TODO(JS): Could make this return a SlangResult as opposed to exception
    addBuiltinSource(coreLanguageScope, "core", getCoreLibraryCode());
    addBuiltinSource(hlslLanguageScope, "hlsl", getHLSLLibraryCode());

    if (compileFlags & slang::CompileStdLibFlag::WriteDocumentation)
    {
        // Not 100% clear where best to get the ASTBuilder from, but from the linkage shouldn't
        // cause any problems with scoping

        ASTBuilder* astBuilder = getBuiltinLinkage()->getASTBuilder();
        SourceManager* sourceManager = getBuiltinSourceManager();

        DiagnosticSink sink(sourceManager, Lexer::sourceLocationLexer);

        List<String> docStrings;

        // For all the modules add their doc output to docStrings
        for (Module* stdlibModule : stdlibModules)
        { 
            RefPtr<ASTMarkup> markup(new ASTMarkup);
            ASTMarkupUtil::extract(stdlibModule->getModuleDecl(), sourceManager, &sink, markup);

            DocMarkdownWriter writer(markup, astBuilder);
            writer.writeAll();
            docStrings.add(writer.getOutput());
        }

        // Combine all together in stdlib-doc.md output fiel
        {
            String fileName("stdlib-doc.md");

            RefPtr<FileStream> stream = new FileStream;
            SLANG_RETURN_ON_FAIL(stream->init(fileName, FileMode::Create));
            StreamWriter writer;
            SLANG_RETURN_ON_FAIL(writer.init(stream));

            for (auto& docString : docStrings)
            {
                SLANG_RETURN_ON_FAIL(writer.write(docString));
            }
        }
    }

    return SLANG_OK;
}

SlangResult Session::loadStdLib(const void* stdLib, size_t stdLibSizeInBytes)
{
    if (m_builtinLinkage->mapNameToLoadedModules.Count())
    {
        // Already have a StdLib loaded
        return SLANG_FAIL;
    }

    // Make a file system to read it from
    RefPtr<ArchiveFileSystem> fileSystem;
    SLANG_RETURN_ON_FAIL(loadArchiveFileSystem(stdLib, stdLibSizeInBytes, fileSystem));

    // Let's try loading serialized modules and adding them
    SLANG_RETURN_ON_FAIL(_readBuiltinModule(fileSystem, coreLanguageScope, "core"));
    SLANG_RETURN_ON_FAIL(_readBuiltinModule(fileSystem, hlslLanguageScope, "hlsl"));
    return SLANG_OK;
}

SlangResult Session::saveStdLib(SlangArchiveType archiveType, ISlangBlob** outBlob)
{
    if (m_builtinLinkage->mapNameToLoadedModules.Count() == 0)
    {
        // There is no standard lib loaded
        return SLANG_FAIL;
    }

    // Make a file system to read it from
    RefPtr<ArchiveFileSystem> fileSystem;
    SLANG_RETURN_ON_FAIL(createArchiveFileSystem(archiveType, fileSystem));

    for (auto& pair : m_builtinLinkage->mapNameToLoadedModules)
    {
        const Name* moduleName = pair.Key;
        Module* module = pair.Value;

        // Set up options
        SerialContainerUtil::WriteOptions options;

        // Save with SourceLocation information
        options.optionFlags |= SerialOptionFlag::SourceLocation;

        // TODO(JS): Should this be the Session::getBuiltinSourceManager()?
        options.sourceManager = m_builtinLinkage->getSourceManager();

        StringBuilder builder;
        builder << moduleName->text << ".slang-module";

        OwnedMemoryStream stream(FileAccess::Write);

        SLANG_RETURN_ON_FAIL(SerialContainerUtil::write(module, options, &stream));

        auto contents = stream.getContents();

        // Write into the file system
        SLANG_RETURN_ON_FAIL(fileSystem->saveFile(builder.getBuffer(), contents.getBuffer(), contents.getCount()));
    }

    // Now need to convert into a blob
    SLANG_RETURN_ON_FAIL(fileSystem->storeArchive(true, outBlob));
    return SLANG_OK;
}

SlangResult Session::_readBuiltinModule(ISlangFileSystem* fileSystem, Scope* scope, String moduleName)
{
    // Get the name of the module
    StringBuilder moduleFilename;
    moduleFilename << moduleName << ".slang-module";

    RiffContainer riffContainer;
    {
        // Load it
        ComPtr<ISlangBlob> blob;
        SLANG_RETURN_ON_FAIL(fileSystem->loadFile(moduleFilename.getBuffer(), blob.writeRef()));

        // Set up a stream
        MemoryStreamBase stream(FileAccess::Read, blob->getBufferPointer(), blob->getBufferSize());

        // Load the riff container
        SLANG_RETURN_ON_FAIL(RiffUtil::read(&stream, riffContainer));
    }
    
    // Load up the module
    
    SerialContainerData containerData;

    Linkage* linkage = getBuiltinLinkage();

    SourceManager* sourceManger = getBuiltinSourceManager();

    NamePool* sessionNamePool = &namePool;
    NamePool* linkageNamePool = linkage->getNamePool();

    SerialContainerUtil::ReadOptions options;
    options.namePool = linkageNamePool;
    options.session = this;
    options.sharedASTBuilder = linkage->getASTBuilder()->getSharedASTBuilder();
    options.sourceManager = sourceManger;
    options.linkage = linkage;

    // Hmm - don't have a suitable sink yet, so attempt to just not have one
    options.sink = nullptr;

    SLANG_RETURN_ON_FAIL(SerialContainerUtil::read(&riffContainer, options, containerData));

    for (auto& srcModule : containerData.modules)
    {
        RefPtr<Module> module(new Module(linkage, srcModule.astBuilder));

        ModuleDecl* moduleDecl = as<ModuleDecl>(srcModule.astRootNode);
        // Set the module back reference on the decl
        moduleDecl->module = module;

        if (moduleDecl)
        {
            if (isFromStdLib(moduleDecl))
            {
                registerBuiltinDecls(this, moduleDecl);
            }
            
            module->setModuleDecl(moduleDecl);
        }

        module->setIRModule(srcModule.irModule);

        // Put in the loaded module map
        linkage->mapNameToLoadedModules.Add(sessionNamePool->getName(moduleName), module);

        // Add the resulting code to the appropriate scope
        if (!scope->containerDecl)
        {
            // We are the first chunk of code to be loaded for this scope
            scope->containerDecl = moduleDecl;
        }
        else
        {
            // We need to create a new scope to link into the whole thing
            auto subScope = linkage->getASTBuilder()->create<Scope>();
            subScope->containerDecl = moduleDecl;
            subScope->nextSibling = scope->nextSibling;
            scope->nextSibling = subScope;
        }

        // We need to retain this AST so that we can use it in other code
        // (Note that the `Scope` type does not retain the AST it points to)
        stdlibModules.add(module);
    }

    return SLANG_OK;
}

ISlangUnknown* Session::getInterface(const Guid& guid)
{
    if(guid == ISlangUnknown::getTypeGuid() || guid == IGlobalSession::getTypeGuid())
        return asExternal(this);
    return nullptr;
}

SLANG_NO_THROW SlangResult SLANG_MCALL Session::createSession(
    slang::SessionDesc const&  desc,
    slang::ISession**          outSession)
{
    RefPtr<ASTBuilder> astBuilder(new ASTBuilder(m_sharedASTBuilder, "Session::astBuilder"));
    RefPtr<Linkage> linkage = new Linkage(this, astBuilder, getBuiltinLinkage());

    Int targetCount = desc.targetCount;
    const uint8_t* targetDescPtr = reinterpret_cast<const uint8_t*>(desc.targets);
    for (Int ii = 0; ii < targetCount; ++ii)
    {
        slang::TargetDesc targetDesc;
        // Copy the size field first.
        memcpy(&targetDesc.structureSize, targetDescPtr, sizeof(size_t));
        // Copy the entire desc structure.
        memcpy(&targetDesc, targetDescPtr, targetDesc.structureSize);
        linkage->addTarget(targetDesc);
        targetDescPtr += targetDesc.structureSize;
    }

    if(desc.flags & slang::kSessionFlag_FalcorCustomSharedKeywordSemantics)
    {
        linkage->m_useFalcorCustomSharedKeywordSemantics = true;
    }

    linkage->setMatrixLayoutMode(desc.defaultMatrixLayoutMode);

    Int searchPathCount = desc.searchPathCount;
    for(Int ii = 0; ii < searchPathCount; ++ii)
    {
        linkage->addSearchPath(desc.searchPaths[ii]);
    }

    Int macroCount = desc.preprocessorMacroCount;
    for(Int ii = 0; ii < macroCount; ++ii)
    {
        auto& macro = desc.preprocessorMacros[ii];
        linkage->addPreprocessorDefine(macro.name, macro.value);
    }

    *outSession = asExternal(linkage.detach());
    return SLANG_OK;
}

SLANG_NO_THROW SlangResult SLANG_MCALL Session::createCompileRequest(slang::ICompileRequest** outCompileRequest)
{
    auto req = new EndToEndCompileRequest(this);

    // Give it a ref (for output)
    req->addRef();
    // Check it is what we think it should be
    SLANG_ASSERT(req->debugGetReferenceCount() == 1);

    *outCompileRequest = req;
    return SLANG_OK;
}

SLANG_NO_THROW SlangProfileID SLANG_MCALL Session::findProfile(
    char const*     name)
{
    return Slang::Profile::lookUp(name).raw;
}

SLANG_NO_THROW SlangCapabilityID SLANG_MCALL Session::findCapability(
    char const* name)
{
    return SlangCapabilityID(Slang::findCapabilityAtom(UnownedTerminatedStringSlice(name)));
}

SLANG_NO_THROW void SLANG_MCALL Session::setDownstreamCompilerPath(
    SlangPassThrough inPassThrough,
    char const* path)
{
    PassThroughMode passThrough = PassThroughMode(inPassThrough);
    SLANG_ASSERT(int(passThrough) > int(PassThroughMode::None) && int(passThrough) < int(PassThroughMode::CountOf));
    
    if (m_downstreamCompilerPaths[int(passThrough)] != path)
    {
        // Make access redetermine compiler
        resetDownstreamCompiler(passThrough);
        // Set the path
        m_downstreamCompilerPaths[int(passThrough)] = path;
    }
}

SLANG_NO_THROW void SLANG_MCALL Session::setDownstreamCompilerPrelude(
    SlangPassThrough inPassThrough,
    char const* prelude)
{
    PassThroughMode downstreamCompiler = PassThroughMode(inPassThrough);
    SLANG_ASSERT(int(downstreamCompiler) > int(PassThroughMode::None) && int(downstreamCompiler) < int(PassThroughMode::CountOf));
    const SourceLanguage sourceLanguage = getDefaultSourceLanguageForDownstreamCompiler(downstreamCompiler);
    setLanguagePrelude(SlangSourceLanguage(sourceLanguage), prelude);
}

SLANG_NO_THROW void SLANG_MCALL Session::getDownstreamCompilerPrelude(
    SlangPassThrough inPassThrough,
    ISlangBlob** outPrelude)
{
    PassThroughMode downstreamCompiler = PassThroughMode(inPassThrough);
    SLANG_ASSERT(int(downstreamCompiler) > int(PassThroughMode::None) && int(downstreamCompiler) < int(PassThroughMode::CountOf));
    const SourceLanguage sourceLanguage = getDefaultSourceLanguageForDownstreamCompiler(downstreamCompiler);
    getLanguagePrelude(SlangSourceLanguage(sourceLanguage), outPrelude);
}

SLANG_NO_THROW void SLANG_MCALL Session::setLanguagePrelude(
    SlangSourceLanguage inSourceLanguage,
    char const* prelude)
{
    SourceLanguage sourceLanguage = SourceLanguage(inSourceLanguage);
    SLANG_ASSERT(int(sourceLanguage) > int(SourceLanguage::Unknown) && int(sourceLanguage) < int(SourceLanguage::CountOf));

    SLANG_ASSERT(sourceLanguage != SourceLanguage::Unknown);

    if (sourceLanguage != SourceLanguage::Unknown)
    {
        m_languagePreludes[int(sourceLanguage)] = prelude;
    }
}

SLANG_NO_THROW void SLANG_MCALL Session::getLanguagePrelude(
    SlangSourceLanguage inSourceLanguage,
    ISlangBlob** outPrelude)
{
    SourceLanguage sourceLanguage = SourceLanguage(inSourceLanguage);
    SLANG_ASSERT(int(sourceLanguage) > int(SourceLanguage::Unknown) && int(sourceLanguage) < int(SourceLanguage::CountOf));

    SLANG_ASSERT(sourceLanguage != SourceLanguage::Unknown);

    *outPrelude = nullptr;
    if (sourceLanguage != SourceLanguage::Unknown)
    {
        *outPrelude = Slang::StringUtil::createStringBlob(m_languagePreludes[int(sourceLanguage)]).detach();
    }
}

SLANG_NO_THROW const char* SLANG_MCALL Session::getBuildTagString()
{
    return ::Slang::getBuildTagString();
}

SLANG_NO_THROW SlangResult SLANG_MCALL Session::setDefaultDownstreamCompiler(SlangSourceLanguage sourceLanguage, SlangPassThrough defaultCompiler)
{
    if (DownstreamCompiler::canCompile(defaultCompiler, sourceLanguage))
    {
        m_defaultDownstreamCompilers[int(sourceLanguage)] = PassThroughMode(defaultCompiler);
        return SLANG_OK;
    }
    return SLANG_FAIL;
}

SlangPassThrough SLANG_MCALL Session::getDefaultDownstreamCompiler(SlangSourceLanguage inSourceLanguage)
{
    SLANG_ASSERT(inSourceLanguage >= 0 && inSourceLanguage < SLANG_SOURCE_LANGUAGE_COUNT_OF);
    auto sourceLanguage = SourceLanguage(inSourceLanguage);
    return SlangPassThrough(m_defaultDownstreamCompilers[int(sourceLanguage)]);
}

void Session::setDownstreamCompilerForTransition(SlangCompileTarget source, SlangCompileTarget target, SlangPassThrough compiler)
{
    if (compiler == SLANG_PASS_THROUGH_NONE)
    {
        // Removing the transition means a default can be used
        m_codeGenTransitionMap.removeTransition(CodeGenTarget(source), CodeGenTarget(target));
    }
    else
    {
        m_codeGenTransitionMap.addTransition(CodeGenTarget(source), CodeGenTarget(target), PassThroughMode(compiler));
    }
}

SlangPassThrough Session::getDownstreamCompilerForTransition(SlangCompileTarget inSource, SlangCompileTarget inTarget)
{
    const CodeGenTarget source = CodeGenTarget(inSource);
    const CodeGenTarget target = CodeGenTarget(inTarget);

    if (m_codeGenTransitionMap.hasTransition(source, target))
    {
        return (SlangPassThrough)m_codeGenTransitionMap.getTransition(source, target);
    }

    // Special case host-callable
    if (target == CodeGenTarget::HostCallable)
    {
        if (source == CodeGenTarget::CSource || source == CodeGenTarget::CPPSource)
        {
            // We prefer LLVM if it's available
            DownstreamCompiler* llvm = getOrLoadDownstreamCompiler(PassThroughMode::LLVM, nullptr);
            if (llvm)
            {
                return SLANG_PASS_THROUGH_LLVM;
            }
        }
    }

    // Use the legacy 'sourceLanguage' default mechanism.
    // This says nothing about the target type, so it is *assumed* the target type is possible
    // If not it will fail when trying to compile to an unknown target
    const SourceLanguage sourceLanguage = (SourceLanguage)TypeConvertUtil::getSourceLanguageFromTarget(inSource);
    if (sourceLanguage != SourceLanguage::Unknown)
    {
        return getDefaultDownstreamCompiler(SlangSourceLanguage(sourceLanguage));
    }

    // Unknwon
    return SLANG_PASS_THROUGH_NONE;
}

DownstreamCompiler* Session::getDownstreamCompiler(CodeGenTarget source, CodeGenTarget target)
{
    PassThroughMode compilerType = (PassThroughMode)getDownstreamCompilerForTransition(SlangCompileTarget(source), SlangCompileTarget(target));
    return getOrLoadDownstreamCompiler(compilerType, nullptr);
}

Profile getEffectiveProfile(EntryPoint* entryPoint, TargetRequest* target)
{
    auto entryPointProfile = entryPoint->getProfile();
    auto targetProfile = target->getTargetProfile();

    // Depending on the target *format* we might have to restrict the
    // profile family to one that makes sense.
    //
    // TODO: Some of this should really be handled as validation at
    // the front-end. People shouldn't be allowed to ask for SPIR-V
    // output with Shader Model 5.0...
    switch(target->getTarget())
    {
    default:
        break;

    case CodeGenTarget::GLSL:
    case CodeGenTarget::GLSL_Vulkan:
    case CodeGenTarget::GLSL_Vulkan_OneDesc:
    case CodeGenTarget::SPIRV:
    case CodeGenTarget::SPIRVAssembly:
        if(targetProfile.getFamily() != ProfileFamily::GLSL)
        {
            targetProfile.setVersion(ProfileVersion::GLSL_110);
        }
        break;

    case CodeGenTarget::HLSL:
    case CodeGenTarget::DXBytecode:
    case CodeGenTarget::DXBytecodeAssembly:
    case CodeGenTarget::DXIL:
    case CodeGenTarget::DXILAssembly:
        if(targetProfile.getFamily() != ProfileFamily::DX)
        {
            targetProfile.setVersion(ProfileVersion::DX_4_0);
        }
        break;
    }

    auto entryPointProfileVersion = entryPointProfile.getVersion();
    auto targetProfileVersion = targetProfile.getVersion();

    // Default to the entry point profile, since we know that has the right stage.
    Profile effectiveProfile = entryPointProfile;

    // Ignore the input from the target profile if it is missing.
    if( targetProfile.getFamily() != ProfileFamily::Unknown )
    {
        // If the target comes from a different profile family, *or* it is from
        // the same family but has a greater version number, then use the target's version.
        if( targetProfile.getFamily() != entryPointProfile.getFamily()
            || (targetProfileVersion > entryPointProfileVersion) )
        {
            effectiveProfile.setVersion(targetProfileVersion);
        }
    }

    // Now consider the possibility that the chosen stage might force an "upgrade"
    // to the profile level.
    ProfileVersion stageMinVersion = ProfileVersion::Unknown;
    switch( effectiveProfile.getFamily() )
    {
    case ProfileFamily::DX:
        switch(effectiveProfile.getStage())
        {
        default:
            break;

        case Stage::RayGeneration:
        case Stage::Intersection:
        case Stage::ClosestHit:
        case Stage::AnyHit:
        case Stage::Miss:
        case Stage::Callable:
            // The DirectX ray tracing stages implicitly
            // require Shader Model 6.3 or later.
            //
            stageMinVersion = ProfileVersion::DX_6_3;
            break;

        //  TODO: Add equivalent logic for geometry, tessellation, and compute stages.
        }
        break;

    case ProfileFamily::GLSL:
        switch(effectiveProfile.getStage())
        {
        default:
            break;

        case Stage::RayGeneration:
        case Stage::Intersection:
        case Stage::ClosestHit:
        case Stage::AnyHit:
        case Stage::Miss:
        case Stage::Callable:
            stageMinVersion = ProfileVersion::GLSL_460;
            break;

        //  TODO: Add equivalent logic for geometry, tessellation, and compute stages.
        }
        break;

    default:
        break;
    }

    if( stageMinVersion > effectiveProfile.getVersion() )
    {
        effectiveProfile.setVersion(stageMinVersion);
    }

    return effectiveProfile;
}


//

Linkage::Linkage(Session* session, ASTBuilder* astBuilder, Linkage* builtinLinkage)
    : m_session(session)
    , m_retainedSession(session)
    , m_sourceManager(&m_defaultSourceManager)
    , m_astBuilder(astBuilder)
{
    getNamePool()->setRootNamePool(session->getRootNamePool());

    m_defaultSourceManager.initialize(session->getBuiltinSourceManager(), nullptr);

    setFileSystem(nullptr);

    // Copy of the built in linkages modules
    if (builtinLinkage)
    {
        for (const auto& pair : builtinLinkage->mapNameToLoadedModules)
        {
            mapNameToLoadedModules.Add(pair.Key, pair.Value);
        }
    }

    {
        RefPtr<CommandLineContext> context = new CommandLineContext;
        m_downstreamArgs = DownstreamArgs(context);

        // Add all of the possible names we allow for downstream tools
        {
            for (Index i = SLANG_PASS_THROUGH_NONE + 1; i < SLANG_PASS_THROUGH_COUNT_OF; ++i)
            {
                m_downstreamArgs.addName(TypeTextUtil::getPassThroughName(SlangPassThrough(i)));
            }

            // Generic downstream tool
            m_downstreamArgs.addName("downstream");
            // Generic downstream linker
            m_downstreamArgs.addName("linker");
        }
    }
}

ISlangUnknown* Linkage::getInterface(const Guid& guid)
{
    if(guid == ISlangUnknown::getTypeGuid() || guid == ISession::getTypeGuid())
        return asExternal(this);

    return nullptr;
}

Linkage::~Linkage()
{
    destroyTypeCheckingCache();
}

TypeCheckingCache* Linkage::getTypeCheckingCache()
{
    if (!m_typeCheckingCache)
    {
        m_typeCheckingCache = new TypeCheckingCache();
    }
    return m_typeCheckingCache;
}

void Linkage::destroyTypeCheckingCache()
{
    delete m_typeCheckingCache;
    m_typeCheckingCache = nullptr;
}

SLANG_NO_THROW slang::IGlobalSession* SLANG_MCALL Linkage::getGlobalSession()
{
    return asExternal(getSessionImpl());
}

void Linkage::addTarget(
    slang::TargetDesc const&  desc)
{
    auto targetIndex = addTarget(CodeGenTarget(desc.format));
    auto target = targets[targetIndex];

    target->setFloatingPointMode(FloatingPointMode(desc.floatingPointMode));
    target->addTargetFlags(desc.flags);
    target->setTargetProfile(Profile(desc.profile));
    target->setLineDirectiveMode(LineDirectiveMode(desc.lineDirectiveMode));
    target->setForceGLSLScalarBufferLayout(desc.forceGLSLScalarBufferLayout);
}

#if 0
SLANG_NO_THROW SlangInt SLANG_MCALL Linkage::getTargetCount()
{
    return targets.getCount();
}

SLANG_NO_THROW slang::ITarget* SLANG_MCALL Linkage::getTargetByIndex(SlangInt index)
{
    if(index < 0) return nullptr;
    if(index >= targets.getCount()) return nullptr;
    return asExternal(targets[index]);
}
#endif

SLANG_NO_THROW slang::IModule* SLANG_MCALL Linkage::loadModule(
    const char*     moduleName,
    slang::IBlob**  outDiagnostics)
{
    DiagnosticSink sink(getSourceManager(), Lexer::sourceLocationLexer);
    try
    {
        auto name = getNamePool()->getName(moduleName);

        auto module = findOrImportModule(name, SourceLoc(), &sink);
        sink.getBlobIfNeeded(outDiagnostics);

        return asExternal(module);

    }
    catch (const AbortCompilationException&)
    {
        sink.getBlobIfNeeded(outDiagnostics);
        return nullptr;
    }
}

SLANG_NO_THROW slang::IModule* SLANG_MCALL Linkage::loadModuleFromSource(
    const char* moduleName,
    slang::IBlob* source,
    slang::IBlob** outDiagnostics)
{
    try
    {
        auto name = getNamePool()->getName(moduleName);
        RefPtr<LoadedModule> loadedModule;
        if (mapNameToLoadedModules.TryGetValue(name, loadedModule))
        {
            return loadedModule;
        }
        DiagnosticSink sink(getSourceManager(), Lexer::sourceLocationLexer);
        auto module = loadModule(
            name,
            PathInfo::makeFromString(moduleName),
            source,
            SourceLoc(),
            &sink);
        sink.getBlobIfNeeded(outDiagnostics);
        return asExternal(module);

    }
    catch (const AbortCompilationException&)
    {
        return nullptr;
    }
}

SLANG_NO_THROW SlangResult SLANG_MCALL Linkage::createCompositeComponentType(
    slang::IComponentType* const*   componentTypes,
    SlangInt                        componentTypeCount,
    slang::IComponentType**         outCompositeComponentType,
    ISlangBlob**                    outDiagnostics)
{
    // Attempting to create a "composite" of just one component type should
    // just return the component type itself, to avoid redundant work.
    //
    if( componentTypeCount == 1)
    {
        auto componentType = componentTypes[0];
        componentType->addRef();
        *outCompositeComponentType = componentType;
        return SLANG_OK;
    }

    DiagnosticSink sink(getSourceManager(), Lexer::sourceLocationLexer);

    List<RefPtr<ComponentType>> childComponents;
    for( Int cc = 0; cc < componentTypeCount; ++cc )
    {
        childComponents.add(asInternal(componentTypes[cc]));
    }

    RefPtr<ComponentType> composite = CompositeComponentType::create(
        this,
        childComponents);

    sink.getBlobIfNeeded(outDiagnostics);

    *outCompositeComponentType = asExternal(composite.detach());
    return SLANG_OK;
}

SLANG_NO_THROW slang::TypeReflection* SLANG_MCALL Linkage::specializeType(
    slang::TypeReflection*          inUnspecializedType,
    slang::SpecializationArg const* specializationArgs,
    SlangInt                        specializationArgCount,
    ISlangBlob**                    outDiagnostics)
{
    auto unspecializedType = asInternal(inUnspecializedType);

    List<Type*> typeArgs;

    for(Int ii = 0; ii < specializationArgCount; ++ii)
    {
        auto& arg = specializationArgs[ii];
        if(arg.kind != slang::SpecializationArg::Kind::Type)
            return nullptr;

        typeArgs.add(asInternal(arg.type));
    }

    DiagnosticSink sink(getSourceManager(), Lexer::sourceLocationLexer);
    auto specializedType = specializeType(unspecializedType, typeArgs.getCount(), typeArgs.getBuffer(), &sink);
    sink.getBlobIfNeeded(outDiagnostics);

    return asExternal(specializedType);
}

SLANG_NO_THROW slang::TypeLayoutReflection* SLANG_MCALL Linkage::getTypeLayout(
    slang::TypeReflection*  inType,
    SlangInt                targetIndex,
    slang::LayoutRules      rules,
    ISlangBlob**            outDiagnostics)
{
    auto type = asInternal(inType);

    if(targetIndex < 0 || targetIndex >= targets.getCount())
        return nullptr;

    auto target = targets[targetIndex];

    // TODO: We need a way to pass through the layout rules
    // that the user requested (e.g., constant buffers vs.
    // structured buffer rules). Right now the API only
    // exposes a single case, so this isn't a big deal.
    //
    SLANG_UNUSED(rules);

    auto typeLayout = target->getTypeLayout(type);

    // TODO: We currently don't have a path for capturing
    // errors that occur during layout (e.g., types that
    // are invalid because of target-specific layout constraints).
    //
    SLANG_UNUSED(outDiagnostics);

    return asExternal(typeLayout);
}

SLANG_NO_THROW slang::TypeReflection* SLANG_MCALL Linkage::getContainerType(
    slang::TypeReflection* inType,
    slang::ContainerType containerType,
    ISlangBlob** outDiagnostics)
{
    auto type = asInternal(inType);

    Type* containerTypeReflection = nullptr;
    ContainerTypeKey key = {inType, containerType};
    if (!m_containerTypes.TryGetValue(key, containerTypeReflection))
    {
        switch (containerType)
        {
        case slang::ContainerType::ConstantBuffer:
            {
                ConstantBufferType* cbType = getASTBuilder()->create<ConstantBufferType>();
                cbType->elementType = type;
                cbType->declRef = getASTBuilder()->getBuiltinDeclRef(
                    "ConstantBuffer", makeConstArrayViewSingle<Val*>(static_cast<Val*>(type)));
                containerTypeReflection = cbType;
            }
            break;
        case slang::ContainerType::ParameterBlock:
            {
                ParameterBlockType* pbType = getASTBuilder()->create<ParameterBlockType>();
                pbType->elementType = type;
                pbType->declRef = getASTBuilder()->getBuiltinDeclRef(
                    "ParameterBlock", makeConstArrayViewSingle<Val*>(static_cast<Val*>(type)));
                containerTypeReflection = pbType;
            }
            break;
        case slang::ContainerType::StructuredBuffer:
            {
                HLSLStructuredBufferType* sbType =
                    getASTBuilder()->create<HLSLStructuredBufferType>();
                sbType->elementType = type;
                sbType->declRef = getASTBuilder()->getBuiltinDeclRef(
                    "HLSLStructuredBufferType", makeConstArrayViewSingle<Val*>(static_cast<Val*>(type)));
                containerTypeReflection = sbType;
            }
            break;
        case slang::ContainerType::UnsizedArray:
            {
                ArrayExpressionType* arrType = getASTBuilder()->getArrayType(type, nullptr);
                containerTypeReflection = arrType;
            }
            break;
        default:
            containerTypeReflection = type;
            break;
        }
        
        m_containerTypes.Add(key, containerTypeReflection);
    }

    SLANG_UNUSED(outDiagnostics);

    return asExternal(containerTypeReflection);
}

SLANG_NO_THROW slang::TypeReflection* SLANG_MCALL Linkage::getDynamicType()
{
    return asExternal(getASTBuilder()->getSharedASTBuilder()->getDynamicType());
}

SLANG_NO_THROW SlangResult SLANG_MCALL Linkage::getTypeRTTIMangledName(
    slang::TypeReflection* type, ISlangBlob** outNameBlob)
{
    auto internalType = asInternal(type);
    if (auto declRefType = as<DeclRefType>(internalType))
    {
        auto name = getMangledName(internalType->getASTBuilder(), declRefType->declRef);
        Slang::ComPtr<ISlangBlob> blob = Slang::StringUtil::createStringBlob(name);
        *outNameBlob = blob.detach();
        return SLANG_OK;
    }
    return SLANG_FAIL;
}

SLANG_NO_THROW SlangResult SLANG_MCALL Linkage::getTypeConformanceWitnessMangledName(
    slang::TypeReflection* type, slang::TypeReflection* interfaceType, ISlangBlob** outNameBlob)
{
    auto subType = asInternal(type);
    auto supType = asInternal(interfaceType);
    auto name = getMangledNameForConformanceWitness(subType->getASTBuilder(), subType, supType);
    Slang::ComPtr<ISlangBlob> blob = Slang::StringUtil::createStringBlob(name);
    *outNameBlob = blob.detach();
    return SLANG_OK;
}

SLANG_NO_THROW SlangResult SLANG_MCALL Linkage::getTypeConformanceWitnessSequentialID(
    slang::TypeReflection* type,
    slang::TypeReflection* interfaceType,
    uint32_t* outId)
{
    auto subType = asInternal(type);
    auto supType = asInternal(interfaceType);

    if (!subType || !supType)
        return SLANG_FAIL;

    auto name = getMangledNameForConformanceWitness(subType->getASTBuilder(), subType, supType);
    auto interfaceName = getMangledTypeName(supType->getASTBuilder(), supType);
    uint32_t resultIndex = 0;
    if (mapMangledNameToRTTIObjectIndex.TryGetValue(name, resultIndex))
    {
        if (outId)
            *outId = resultIndex;
        return SLANG_OK;
    }
    auto idAllocator = mapInterfaceMangledNameToSequentialIDCounters.TryGetValue(interfaceName);
    if (!idAllocator)
    {
        mapInterfaceMangledNameToSequentialIDCounters[interfaceName] = 0;
        idAllocator = mapInterfaceMangledNameToSequentialIDCounters.TryGetValue(interfaceName);
    }
    resultIndex = (*idAllocator);
    ++(*idAllocator);
    mapMangledNameToRTTIObjectIndex[name] = resultIndex;
    if (outId)
        *outId = resultIndex;
    return SLANG_OK;
}

SLANG_NO_THROW SlangResult SLANG_MCALL Linkage::createTypeConformanceComponentType(
    slang::TypeReflection* type,
    slang::TypeReflection* interfaceType,
    slang::ITypeConformance** outConformanceComponentType,
    SlangInt conformanceIdOverride,
    ISlangBlob** outDiagnostics)
{
    RefPtr<TypeConformance> result;
    DiagnosticSink sink;
    try
    {
        SharedSemanticsContext sharedSemanticsContext(this, nullptr, &sink);
        SemanticsVisitor visitor(&sharedSemanticsContext);
        auto witness =
            visitor.tryGetSubtypeWitness((Slang::Type*)type, (Slang::Type*)interfaceType);
        if (auto subtypeWitness = as<SubtypeWitness>(witness))
        {
            result = new TypeConformance(this, subtypeWitness, conformanceIdOverride, &sink);
        }
    }
    catch (...)
    {}
    sink.getBlobIfNeeded(outDiagnostics);
    bool success = (result != nullptr);
    *outConformanceComponentType = result.detach();
    return success ? SLANG_OK : SLANG_FAIL;
}

SLANG_NO_THROW SlangResult SLANG_MCALL Linkage::createCompileRequest(
    SlangCompileRequest**   outCompileRequest)
{
    auto compileRequest = new EndToEndCompileRequest(this);
    compileRequest->addRef();
    *outCompileRequest = asExternal(compileRequest);
    return SLANG_OK;
}

SlangResult Linkage::addSearchPath(
    char const* path)
{
    searchDirectories.searchDirectories.add(Slang::SearchDirectory(path));
    return SLANG_OK;
}

SlangResult Linkage::addPreprocessorDefine(
    char const* name,
    char const* value)
{
    preprocessorDefinitions[name] = value;
    return SLANG_OK;
}

SlangResult Linkage::setMatrixLayoutMode(
    SlangMatrixLayoutMode mode)
{
    defaultMatrixLayoutMode = MatrixLayoutMode(mode);
    return SLANG_OK;
}

//
// TargetRequest
//

TargetRequest::TargetRequest(Linkage* linkage, CodeGenTarget format)
    : linkage(linkage)
    , format(format)
{}


Session* TargetRequest::getSession()
{
    return linkage->getSessionImpl();
}

MatrixLayoutMode TargetRequest::getDefaultMatrixLayoutMode()
{
    return linkage->getDefaultMatrixLayoutMode();
}

void TargetRequest::addCapability(CapabilityAtom capability)
{
    rawCapabilities.add(capability);
    cookedCapabilities = CapabilitySet::makeEmpty();
}

CapabilitySet TargetRequest::getTargetCaps()
{
    if(!cookedCapabilities.isEmpty())
        return cookedCapabilities;

    // The full `CapabilitySet` for the target will be computed
    // from the combination of the code generation format, and
    // the profile.
    //
    // Note: the preofile might have been set in a way that is
    // inconsistent with the output code format of SPIR-V, but
    // a profile of Direct3D Shader Model 5.1. In those cases,
    // the format should always override the implications in
    // the profile.
    //
    // TODO: This logic isn't currently taking int account
    // the information in the profile, because the current
    // `CapabilityAtom`s that we support don't include any
    // of the details there (e.g., the shader model versions).
    //
    // Eventually, we'd want to have a rich set of capability
    // atoms, so that most of the information about what operations
    // are available where can be directly encoded on the declarations.

    List<CapabilityAtom> atoms;
    switch(format)
    {
    case CodeGenTarget::GLSL:
    case CodeGenTarget::GLSL_Vulkan:
    case CodeGenTarget::GLSL_Vulkan_OneDesc:
        atoms.add(CapabilityAtom::GLSL);
        break;
    case CodeGenTarget::SPIRV:
    case CodeGenTarget::SPIRVAssembly:
        if (targetFlags & SLANG_TARGET_FLAG_GENERATE_SPIRV_DIRECTLY)
        {
            atoms.add(CapabilityAtom::SPIRV_DIRECT);
        }
        else
        {
            atoms.add(CapabilityAtom::GLSL);
        }
        break;

    case CodeGenTarget::HLSL:
    case CodeGenTarget::DXBytecode:
    case CodeGenTarget::DXBytecodeAssembly:
    case CodeGenTarget::DXIL:
    case CodeGenTarget::DXILAssembly:
        atoms.add(CapabilityAtom::HLSL);
        break;

    case CodeGenTarget::CSource:
        atoms.add(CapabilityAtom::C);
        break;

    case CodeGenTarget::CPPSource:
    case CodeGenTarget::Executable:
    case CodeGenTarget::SharedLibrary:
    case CodeGenTarget::HostCallable:
        atoms.add(CapabilityAtom::CPP);
        break;

    case CodeGenTarget::CUDASource:
    case CodeGenTarget::PTX:
        atoms.add(CapabilityAtom::CUDA);
        break;

    default:
        break;
    }
    for(auto atom : rawCapabilities)
        atoms.add(atom);

    cookedCapabilities = CapabilitySet(atoms);
    return cookedCapabilities;
}


TypeLayout* TargetRequest::getTypeLayout(Type* type)
{
    // TODO: We are not passing in a `ProgramLayout` here, although one
    // is nominally required to establish the global ordering of
    // generic type parameters, which might be referenced from field types.
    //
    // The solution here is to make sure that the reflection data for
    // uses of global generic/existential types does *not* include any
    // kind of index in that global ordering, and just refers to the
    // parameter instead (leaving the user to figure out how that
    // maps to the ordering via some API on the program layout).
    //
    auto layoutContext = getInitialLayoutContextForTarget(this, nullptr);

    RefPtr<TypeLayout> result;
    if (getTypeLayouts().TryGetValue(type, result))
        return result.Ptr();
    result = createTypeLayout(layoutContext, type);
    getTypeLayouts()[type] = result;
    return result.Ptr();
}

//
// TranslationUnitRequest
//

TranslationUnitRequest::TranslationUnitRequest(
    FrontEndCompileRequest* compileRequest)
    : compileRequest(compileRequest)
{
    module = new Module(compileRequest->getLinkage());
}


Session* TranslationUnitRequest::getSession()
{
    return compileRequest->getSession();
}

NamePool* TranslationUnitRequest::getNamePool()
{
    return compileRequest->getNamePool();
}

SourceManager* TranslationUnitRequest::getSourceManager()
{
    return compileRequest->getSourceManager();
}

void TranslationUnitRequest::addSourceFile(SourceFile* sourceFile)
{
    m_sourceFiles.add(sourceFile);

    // We want to record that the compiled module has a dependency
    // on the path of the source file, but we also need to account
    // for cases where the user added a source string/blob without
    // an associated path and/or wasn't from a file.

    auto pathInfo = sourceFile->getPathInfo();
    if (pathInfo.hasFileFoundPath())
    {
        getModule()->addFilePathDependency(pathInfo.foundPath);
    }
}


//

static ISlangWriter* _getDefaultWriter(WriterChannel chan)
{
    static FileWriter stdOut(stdout, WriterFlag::IsStatic | WriterFlag::IsUnowned);
    static FileWriter stdError(stderr, WriterFlag::IsStatic | WriterFlag::IsUnowned);
    static NullWriter nullWriter(WriterFlag::IsStatic | WriterFlag::IsConsole);

    switch (chan)
    {
        case WriterChannel::StdError:    return &stdError;
        case WriterChannel::StdOutput:   return &stdOut;
        case WriterChannel::Diagnostic:  return &nullWriter;
        default:
        {
            SLANG_ASSERT(!"Unknown type");
            return &stdError;
        }
    }
}

void EndToEndCompileRequest::setWriter(WriterChannel chan, ISlangWriter* writer)
{
    // If the user passed in null, we will use the default writer on that channel
    m_writers->setWriter(SlangWriterChannel(chan), writer ? writer : _getDefaultWriter(chan));

    // For diagnostic output, if the user passes in nullptr, we set on mSink.writer as that enables buffering on DiagnosticSink
    if (chan == WriterChannel::Diagnostic)
    {
        m_sink.writer = writer; 
    }
}

SlangResult Linkage::loadFile(String const& path, PathInfo& outPathInfo, ISlangBlob** outBlob)
{
    outPathInfo.type = PathInfo::Type::Unknown;

    SLANG_RETURN_ON_FAIL(m_fileSystemExt->loadFile(path.getBuffer(), outBlob));

    ComPtr<ISlangBlob> uniqueIdentity;
    // Get the unique identity
    if (SLANG_FAILED(m_fileSystemExt->getFileUniqueIdentity(path.getBuffer(), uniqueIdentity.writeRef())))
    {
        // We didn't get a unique identity, so go with just a found path
        outPathInfo.type = PathInfo::Type::FoundPath;
        outPathInfo.foundPath = path;
    }
    else
    {
        outPathInfo = PathInfo::makeNormal(path, StringUtil::getString(uniqueIdentity));
    }
    return SLANG_OK;
}

Expr* Linkage::parseTermString(String typeStr, Scope* scope)
{
    // Create a SourceManager on the stack, so any allocations for 'SourceFile'/'SourceView' etc will be cleaned up
    SourceManager localSourceManager;
    localSourceManager.initialize(getSourceManager(), nullptr);
        
    Slang::SourceFile* srcFile = localSourceManager.createSourceFileWithString(PathInfo::makeTypeParse(), typeStr);
    
    // We'll use a temporary diagnostic sink  
    DiagnosticSink sink(&localSourceManager, nullptr);

    // RAII type to make make sure current SourceManager is restored after parse.
    // Use RAII - to make sure everything is reset even if an exception is thrown.
    struct ScopeReplaceSourceManager
    {
        ScopeReplaceSourceManager(Linkage* linkage, SourceManager* replaceManager):
            m_linkage(linkage),
            m_originalSourceManager(linkage->getSourceManager())
        {
            linkage->setSourceManager(replaceManager);
        }

        ~ScopeReplaceSourceManager()
        {
            m_linkage->setSourceManager(m_originalSourceManager);
        }

        private:
        Linkage* m_linkage;
        SourceManager* m_originalSourceManager;
    };

    // We need to temporarily replace the SourceManager for this CompileRequest
    ScopeReplaceSourceManager scopeReplaceSourceManager(this, &localSourceManager);

    auto tokens = preprocessSource(
        srcFile,
        &sink,
        nullptr,
        Dictionary<String,String>(),
        this);

    return parseTermFromSourceFile(
        getASTBuilder(),
        tokens, &sink, scope, getNamePool(), SourceLanguage::Slang);
}

Type* checkProperType(
    Linkage*        linkage,
    TypeExp         typeExp,
    DiagnosticSink* sink);

Type* ComponentType::getTypeFromString(
        String const&   typeStr,
        DiagnosticSink* sink)
{
    // If we've looked up this type name before,
    // then we can re-use it.
    //
    Type* type = nullptr;
    if(m_types.TryGetValue(typeStr, type))
        return type;


    // TODO(JS): For now just used the linkages ASTBuilder to keep on scope
    //
    // The parseTermString uses the linkage ASTBuilder for it's parsing.
    // 
    // It might be possible to just create a temporary ASTBuilder - the worry though is
    // that the parsing sets a member variable in AST node to one of these scopes, and then
    // it become a dangling pointer. So for now we go with the linkages.
    auto astBuilder = getLinkage()->getASTBuilder();

    // Otherwise, we need to start looking in
    // the modules that were directly or
    // indirectly referenced.
    //
    Scope* scope = _createScopeForLegacyLookup(astBuilder);

    auto linkage = getLinkage();
    Expr* typeExpr = linkage->parseTermString(
        typeStr, scope);
    type = checkProperType(linkage, TypeExp(typeExpr), sink);

    if( type )
    {
        m_types[typeStr] = type;
    }
    return type;
}

CompileRequestBase::CompileRequestBase(
    Linkage*        linkage,
    DiagnosticSink* sink)
    : m_linkage(linkage)
    , m_sink(sink)
{}


FrontEndCompileRequest::FrontEndCompileRequest(
    Linkage*        linkage,
    StdWriters*     writers, 
    DiagnosticSink* sink)
    : CompileRequestBase(linkage, sink)
    , m_writers(writers)
{
}

    /// Handlers for preprocessor callbacks to use when doing ordinary front-end compilation
struct FrontEndPreprocessorHandler : PreprocessorHandler
{
public:
    FrontEndPreprocessorHandler(
        Module*         module,
        ASTBuilder*     astBuilder,
        DiagnosticSink* sink)
        : m_module(module)
        , m_astBuilder(astBuilder)
        , m_sink(sink)
    {
    }

protected:
    Module*         m_module;
    ASTBuilder*     m_astBuilder;
    DiagnosticSink* m_sink;

    // The first task that this handler tries to deal with is
    // capturing all the files on which a module is dependent.
    //
    // That information is exposed through public APIs and used
    // by applications to decide when they need to "hot reload"
    // their shader code.
    //
    void handleFileDependency(String const& path) SLANG_OVERRIDE
    {
        m_module->addFilePathDependency(path);
    }

    // The second task that this handler deals with is detecting
    // whether any macro values were set in a given source file
    // that are semantically relevant to other stages of compilation.
    //
    void handleEndOfTranslationUnit(Preprocessor* preprocessor) SLANG_OVERRIDE
    {
        // We look at the preprocessor state after reading the entire
        // source file/string, in order to see if any macros have been
        // set that should be considered semantically relevant for
        // later stages of compilation.
        //
        // Note: Checking the macro environment *after* preprocessing is complete
        // means that we can treat macros introduced via `-D` options or the API
        // equivalently to macros introduced via `#define`s in user code.
        //
        // For now, the only case of semantically-relevant macros we need to worrry
        // about are the NVAPI macros used to establish the register/space to use.
        //
        static const char* kNVAPIRegisterMacroName = "NV_SHADER_EXTN_SLOT";
        static const char* kNVAPISpaceMacroName = "NV_SHADER_EXTN_REGISTER_SPACE";

        // For NVAPI use, the `NV_SHADER_EXTN_SLOT` macro is required to be defined.
        //
        String nvapiRegister;
        SourceLoc nvapiRegisterLoc;
        if(!SLANG_FAILED(findMacroValue(preprocessor, kNVAPIRegisterMacroName, nvapiRegister, nvapiRegisterLoc)))
        {
            // In contrast, NVAPI can be used without defining `NV_SHADER_EXTN_REGISTER_SPACE`,
            // which effectively defaults to `space0`.
            //
            String nvapiSpace = "space0";
            SourceLoc nvapiSpaceLoc;
            findMacroValue(preprocessor, kNVAPISpaceMacroName, nvapiSpace, nvapiSpaceLoc);

            // We are going to store the values of these macros on the AST-level `ModuleDecl`
            // so that they will be available to later processing stages.
            //
            auto moduleDecl = m_module->getModuleDecl();

            if(auto existingModifier = moduleDecl->findModifier<NVAPISlotModifier>())
            {
                // If there is already a modifier attached to the module (perhaps
                // because of preprocessing a different source file, or because
                // of settings established via command-line options), then we
                // need to validate that the values being set in this file
                // match those already set (or else there is likely to be
                // some kind of error in the user's code).
                //
                _validateNVAPIMacroMatch(kNVAPIRegisterMacroName, existingModifier->registerName, nvapiRegister,  nvapiRegisterLoc);
                _validateNVAPIMacroMatch(kNVAPISpaceMacroName,    existingModifier->spaceName,    nvapiSpace,     nvapiSpaceLoc);
            }
            else
            {
                // If there is no existing modifier on the module, then we
                // take responsibility for adding one, based on the macro
                // values we saw.
                //
                auto modifier = m_astBuilder->create<NVAPISlotModifier>();
                modifier->loc = nvapiRegisterLoc;
                modifier->registerName = nvapiRegister;
                modifier->spaceName = nvapiSpace;

                addModifier(moduleDecl, modifier);
            }
        }
    }

        /// Validate that a re-defintion of an NVAPI-related macro matches any previous definition
    void _validateNVAPIMacroMatch(
        char const*     macroName,
        String const&   existingValue,
        String const&   newValue,
        SourceLoc       loc)
    {
        if( existingValue != newValue )
        {
            m_sink->diagnose(loc, Diagnostics::nvapiMacroMismatch, macroName, existingValue, newValue);
        }
    }
};


// Holds the hierarchy of views, the children being views that were 'initiated' (have an initiating SourceLoc) in the parent. 
typedef Dictionary<SourceView*, List<SourceView*>> ViewInitiatingHierarchy;

// Calculate the hierarchy from the sourceManager
static void _calcViewInitiatingHierarchy(SourceManager* sourceManager, ViewInitiatingHierarchy& outHierarchy)
{
    const List<SourceView*> emptyList;
    outHierarchy.Clear();

    // Iterate over all managers
    for (SourceManager* curManager = sourceManager; curManager; curManager = curManager->getParent())
    {
        // Iterate over all views
        for (SourceView* view : curManager->getSourceViews())
        {
            if (view->getInitiatingSourceLoc().isValid())
            {
                // Look up the view it came from
                SourceView* parentView = sourceManager->findSourceViewRecursively(view->getInitiatingSourceLoc());
                if (parentView)
                {
                    List<SourceView*>& children = outHierarchy.GetOrAddValue(parentView, emptyList);
                    // It shouldn't have already been added
                    SLANG_ASSERT(children.indexOf(view) < 0);
                    children.add(view);
                }
            }
        }
    }

    // Order all the children, by their raw SourceLocs. This is desirable, so that a trivial traversal
    // will traverse children in the order they are initiated in the parent source.
    // This assumes they increase in SourceLoc implies an later within a source file - this is true currently.
    for (auto& pair : outHierarchy)
    {
        pair.Value.sort([](SourceView* a, SourceView* b) -> bool { return a->getInitiatingSourceLoc().getRaw() < b->getInitiatingSourceLoc().getRaw(); });
    }
}

// Given a source file, find the view that is the initial SourceView use of the source. It must have
// an initiating SourceLoc that is not valid.
static SourceView* _findInitialSourceView(SourceFile* sourceFile)
{
    // TODO(JS):
    // This might be overkill - presumably the SourceView would belong to the same manager as it's SourceFile?
    // That is not enforced by the SourceManager in any way though so we just search all managers, and all views.
    for (SourceManager* sourceManager = sourceFile->getSourceManager(); sourceManager; sourceManager = sourceManager->getParent())
    {
        for (SourceView* view : sourceManager->getSourceViews())
        {
            if (view->getSourceFile() == sourceFile && !view->getInitiatingSourceLoc().isValid())
            {
                return view;
            }
        }        
    }

    return nullptr;
}

static void _outputInclude(SourceFile* sourceFile, Index depth, DiagnosticSink* sink)
{
    StringBuilder buf;

    for (Index i = 0; i < depth; ++i)
    {
        buf << "  ";
    }

    // Output the found path for now
    // TODO(JS). We could use the verbose paths flag to control what path is output -> as it may be useful to output the full path
    // for example

    const PathInfo& pathInfo = sourceFile->getPathInfo();
    buf << "'" << pathInfo.foundPath << "'";

    // TODO(JS)?
    // You might want to know where this include was from.
    // If I output this though there will be a problem... as the indenting won't be clearly shown.
    // Perhaps I output in two sections, one the hierarchy and the other the locations of the includes?

    sink->diagnose(SourceLoc(), Diagnostics::includeOutput, buf);
}

static void _outputIncludesRec(SourceView* sourceView, Index depth, ViewInitiatingHierarchy& hierarchy, DiagnosticSink* sink)
{
    SourceFile* sourceFile = sourceView->getSourceFile();
    const PathInfo& pathInfo = sourceFile->getPathInfo();

    switch (pathInfo.type)
    {
        case PathInfo::Type::TokenPaste:
        case PathInfo::Type::CommandLine:
        case PathInfo::Type::TypeParse:
        {
            // If any of these types we don't output
            return;
        }
        default: break;
    }

    // Okay output this file at the current depth
    _outputInclude(sourceFile, depth, sink);

    // Now recurse to all of the children at the next depth
    List<SourceView*>* children = hierarchy.TryGetValue(sourceView);
    if (children)
    {
        for (SourceView* child : *children)
        {
            _outputIncludesRec(child, depth + 1, hierarchy, sink);
        }
    }
}

static void _outputPreprocessorTokens(const TokenList& toks, ISlangWriter* writer)
{
    if (writer == nullptr)
    {
        return;
    }

    StringBuilder buf;
    for (const auto& tok : toks)
    {
        buf << tok.getContent();
        // We'll separate tokens with space for now
        buf.appendChar(' ');
    }

    buf.appendChar('\n');

    writer->write(buf.getBuffer(), buf.getLength());
}

static void _outputIncludes(const List<SourceFile*>& sourceFiles, SourceManager* sourceManager, DiagnosticSink* sink)
{
    // Set up the hierarchy to know how all the source views relate. This could be argued as overkill, but makes recursive
    // output pretty simple
    ViewInitiatingHierarchy hierarchy;
    _calcViewInitiatingHierarchy(sourceManager, hierarchy);

    // For all the source files
    for (SourceFile* sourceFile : sourceFiles)
    {
        // Find an initial view (this is the view of this file, that doesn't have an initiating loc)
        SourceView* sourceView = _findInitialSourceView(sourceFile);
        if (!sourceView)
        {
            // Okay, didn't find one, so just output the file
            _outputInclude(sourceFile, 0, sink);
        }
        else
        {
            // Output from this view recursively
            _outputIncludesRec(sourceView, 0, hierarchy, sink);
        }
    }
}

void FrontEndCompileRequest::parseTranslationUnit(
    TranslationUnitRequest* translationUnit)
{
    auto linkage = getLinkage();

    // TODO(JS): NOTE! Here we are using the searchDirectories on the linkage. This is because
    // currently the API only allows the setting search paths on linkage.
    // 
    // Here we should probably be using the searchDirectories on the FrontEndCompileRequest.
    // If searchDirectories.parent pointed to the one in the Linkage would mean linkage paths
    // would be checked too (after those on the FrontEndCompileRequest). 
    IncludeSystem includeSystem(&linkage->searchDirectories, linkage->getFileSystemExt(), linkage->getSourceManager());

    Scope* languageScope = nullptr;
    switch (translationUnit->sourceLanguage)
    {
    case SourceLanguage::HLSL:
        languageScope = getSession()->hlslLanguageScope;
        break;

    case SourceLanguage::Slang:
    default:
        languageScope = getSession()->slangLanguageScope;
        break;
    }

    Dictionary<String, String> combinedPreprocessorDefinitions;
    for(auto& def : getLinkage()->preprocessorDefinitions)
        combinedPreprocessorDefinitions.Add(def.Key, def.Value);
    for(auto& def : preprocessorDefinitions)
        combinedPreprocessorDefinitions.Add(def.Key, def.Value);
    for(auto& def : translationUnit->preprocessorDefinitions)
        combinedPreprocessorDefinitions.Add(def.Key, def.Value);

    auto module = translationUnit->getModule();

    ASTBuilder* astBuilder = module->getASTBuilder();

    //ASTBuilder* astBuilder = linkage->getASTBuilder();

    ModuleDecl* translationUnitSyntax = astBuilder->create<ModuleDecl>();

    translationUnitSyntax->nameAndLoc.name = translationUnit->moduleName;
    translationUnitSyntax->module = module;
    module->setModuleDecl(translationUnitSyntax);

    // When compiling a module of code that belongs to the Slang
    // standard library, we add a modifier to the module to act
    // as a marker, so that downstream code can detect declarations
    // that came from the standard library (by walking up their
    // chain of ancestors and looking for the marker), and treat
    // them differently from user declarations.
    //
    // We are adding the marker here, before we even parse the
    // code in the module, in case the subsequent steps would
    // like to treat the standard library differently. Alternatively
    // we could pass down the `m_isStandardLibraryCode` flag to
    // these passes.
    //
    if( m_isStandardLibraryCode )
    {
        translationUnitSyntax->modifiers.first = astBuilder->create<FromStdLibModifier>();
    }

    // We use a custom handler for preprocessor callbacks, to
    // ensure that relevant state that is only visible during
    // preprocessoing can be communicated to later phases of
    // compilation.
    //
    FrontEndPreprocessorHandler preprocessorHandler(module, astBuilder, getSink());

    for (auto sourceFile : translationUnit->getSourceFiles())
    {
        auto tokens = preprocessSource(
            sourceFile,
            getSink(),
            &includeSystem,
            combinedPreprocessorDefinitions,
            getLinkage(),
            &preprocessorHandler);

        if (outputIncludes)
        {
            _outputIncludes(translationUnit->getSourceFiles(), getSink()->getSourceManager(), getSink());
        }

        if (outputPreprocessor)
        {
            if (m_writers)
            {
                _outputPreprocessorTokens(tokens, m_writers->getWriter(SLANG_WRITER_CHANNEL_STD_OUTPUT));
            }
            // If we output the preprocessor output then we are done doing anything else
            return;
        }

        parseSourceFile(
            astBuilder,
            translationUnit,
            tokens,
            getSink(),
            languageScope);

        // Let's try dumping

        if (shouldDumpAST)
        {
            StringBuilder buf;
            SourceWriter writer(linkage->getSourceManager(), LineDirectiveMode::None);

            ASTDumpUtil::dump(translationUnit->getModuleDecl(), ASTDumpUtil::Style::Flat, 0, &writer);

            const String& path = sourceFile->getPathInfo().foundPath;
            if (path.getLength())
            {
                String fileName = Path::getFileNameWithoutExt(path);
                fileName.append(".slang-ast");

                File::writeAllText(fileName, writer.getContent());
            }
        }



#if 0
        // Test serialization
        {
            ASTSerialTestUtil::testSerialize(translationUnit->getModuleDecl(), getSession()->getRootNamePool(), getLinkage()->getASTBuilder()->getSharedASTBuilder(), getSourceManager());
        }
#endif

    }
}

RefPtr<ComponentType> createUnspecializedGlobalComponentType(
        FrontEndCompileRequest* compileRequest);

RefPtr<ComponentType> createUnspecializedGlobalAndEntryPointsComponentType(
        FrontEndCompileRequest*         compileRequest,
        List<RefPtr<ComponentType>>&    outUnspecializedEntryPoints);

RefPtr<ComponentType> createSpecializedGlobalComponentType(
    EndToEndCompileRequest* endToEndReq);

RefPtr<ComponentType> createSpecializedGlobalAndEntryPointsComponentType(
    EndToEndCompileRequest*         endToEndReq,
    List<RefPtr<ComponentType>>&    outSpecializedEntryPoints);

void FrontEndCompileRequest::checkAllTranslationUnits()
{
    // Iterate over all translation units and
    // apply the semantic checking logic.
    for( auto& translationUnit : translationUnits )
    {
        checkTranslationUnit(translationUnit.Ptr());
    }
    checkEntryPoints();
}

void FrontEndCompileRequest::generateIR()
{
    // Our task in this function is to generate IR code
    // for all of the declarations in the translation
    // units that were loaded.

    // Each translation unit is its own little world
    // for code generation (we are not trying to
    // replicate the GLSL linkage model), and so
    // we will generate IR for each (if needed)
    // in isolation.
    for( auto& translationUnit : translationUnits )
    {
        // We want to only run generateIRForTranslationUnit once here. This is for two side effects:
        // * it can dump ir 
        // * it can generate diagnostics

        /// Generate IR for translation unit.
        /// TODO(JS): Use the linkage ASTBuilder, because it seems possible that cross module constructs are possible in
        /// ir lowering.
        RefPtr<IRModule> irModule(generateIRForTranslationUnit(getLinkage()->getASTBuilder(), translationUnit));

        if (verifyDebugSerialization)
        {
            SerialContainerUtil::WriteOptions options;

            options.compressionType = SerialCompressionType::None;
            options.sourceManager = getSourceManager();
            options.optionFlags |= SerialOptionFlag::SourceLocation;

            // Verify debug information
            if (SLANG_FAILED(SerialContainerUtil::verifyIRSerialize(irModule, getSession(), options)))
            {
                getSink()->diagnose(irModule->getModuleInst()->sourceLoc, Diagnostics::serialDebugVerificationFailed);
            }
        }

        if (useSerialIRBottleneck)
        {
            IRSerialData serialData;
            {
                // Write IR out to serialData - copying over SourceLoc information directly
                IRSerialWriter writer;
                writer.write(irModule, nullptr, SerialOptionFlag::RawSourceLocation, &serialData);

                // Destroy irModule such that memory can be used for newly constructed read irReadModule  
                irModule = nullptr;
            }
            RefPtr<IRModule> irReadModule;
            {
                // Read IR back from serialData
                IRSerialReader reader;
                reader.read(serialData, getSession(), nullptr, irReadModule);
            }

            // Set irModule to the read module
            irModule = irReadModule;
        }

        // Set the module on the translation unit
        translationUnit->getModule()->setIRModule(irModule);
    }
}

// Try to infer a single common source language for a request
static SourceLanguage inferSourceLanguage(FrontEndCompileRequest* request)
{
    SourceLanguage language = SourceLanguage::Unknown;
    for (auto& translationUnit : request->translationUnits)
    {
        // Allow any other language to overide Slang as a choice
        if (language == SourceLanguage::Unknown
            || language == SourceLanguage::Slang)
        {
            language = translationUnit->sourceLanguage;
        }
        else if (language == translationUnit->sourceLanguage)
        {
            // same language as we currently have, so keep going
        }
        else
        {
            // we found a mismatch, so inference fails
            return SourceLanguage::Unknown;
        }
    }
    return language;
}

SlangResult FrontEndCompileRequest::executeActionsInner()
{
    // We currently allow GlSL files on the command line so that we can
    // drive our "pass-through" mode, but we really want to issue an error
    // message if the user is seriously asking us to compile them.
    for (auto& translationUnit : translationUnits)
    {
        switch(translationUnit->sourceLanguage)
        {
        default:
            break;

        case SourceLanguage::GLSL:
            getSink()->diagnose(SourceLoc(), Diagnostics::glslIsNotSupported);
            return SLANG_FAIL;
        }
    }


    // Parse everything from the input files requested
    for (auto& translationUnit : translationUnits)
    {
        parseTranslationUnit(translationUnit.Ptr());
    }

    if (outputPreprocessor)
    {
        // If doing pre-processor output, then we are done
        return SLANG_OK;
    }

    if (getSink()->getErrorCount() != 0)
        return SLANG_FAIL;

    // Perform semantic checking on the whole collection
    checkAllTranslationUnits();
    if (getSink()->getErrorCount() != 0)
        return SLANG_FAIL;

    // After semantic checking is performed we can try and output doc information for this
    if (shouldDocument)
    {
        // Not 100% clear where best to get the ASTBuilder from, but from the linkage shouldn't
        // cause any problems with scoping
        ASTBuilder* astBuilder = getLinkage()->getASTBuilder();

        ISlangWriter* writer = getSink()->writer;

        // Write output to the diagnostic writer
        if (writer)
        {
            for (TranslationUnitRequest* translationUnit : translationUnits)
            {
                RefPtr<ASTMarkup> markup(new ASTMarkup);
                ASTMarkupUtil::extract(translationUnit->getModuleDecl(), getSourceManager(), getSink(), markup);

                // Convert to markdown            
                DocMarkdownWriter markdownWriter(markup, astBuilder);
                markdownWriter.writeAll();

                UnownedStringSlice docText = markdownWriter.getOutput().getUnownedSlice();
                writer->write(docText.begin(), docText.getLength());            
            }
        }
    }

    // Look up all the entry points that are expected,
    // and use them to populate the `program` member.
    //
    m_globalComponentType = createUnspecializedGlobalComponentType(this);
    if (getSink()->getErrorCount() != 0)
        return SLANG_FAIL;

    m_globalAndEntryPointsComponentType = createUnspecializedGlobalAndEntryPointsComponentType(
        this,
        m_unspecializedEntryPoints);
    if (getSink()->getErrorCount() != 0)
        return SLANG_FAIL;

    // We always generate IR for all the translation units.
    //
    // TODO: We may eventually have a mode where we skip
    // IR codegen and only produce an AST (e.g., for use when
    // debugging problems in the parser or semantic checking),
    // but for now there are no cases where not having IR
    // makes sense.
    //
    generateIR();
    if (getSink()->getErrorCount() != 0)
        return SLANG_FAIL;

    // Do parameter binding generation, for each compilation target.
    //
    for(auto targetReq : getLinkage()->targets)
    {
        auto targetProgram = m_globalAndEntryPointsComponentType->getTargetProgram(targetReq);
        targetProgram->getOrCreateLayout(getSink());
        targetProgram->getOrCreateIRModuleForLayout(getSink());
    }
    if (getSink()->getErrorCount() != 0)
        return SLANG_FAIL;

    return SLANG_OK;
}

BackEndCompileRequest::BackEndCompileRequest(
    Linkage*        linkage,
    DiagnosticSink* sink,
    ComponentType*  program)
    : CompileRequestBase(linkage, sink)
    , m_program(program)
    , m_dumpIntermediatePrefix("slang-dump-")

{
}

EndToEndCompileRequest::EndToEndCompileRequest(
    Session* session)
    : m_session(session)
    , m_sink(nullptr, Lexer::sourceLocationLexer)
{
    RefPtr<ASTBuilder> astBuilder(new ASTBuilder(session->m_sharedASTBuilder, "EndToEnd::Linkage::astBuilder"));
    m_linkage = new Linkage(session, astBuilder, session->getBuiltinLinkage());
    init();
}

EndToEndCompileRequest::EndToEndCompileRequest(
    Linkage* linkage)
    : m_session(linkage->getSessionImpl())
    , m_linkage(linkage)
    , m_sink(nullptr, Lexer::sourceLocationLexer)
{
    init();
}

SLANG_NO_THROW SlangResult SLANG_MCALL EndToEndCompileRequest::queryInterface(SlangUUID const& uuid, void** outObject)
{
    if (uuid == EndToEndCompileRequest::getTypeGuid())
    {
        // Special case to cast directly into internal type
        // NOTE! No addref(!)
        *outObject = this;
        return SLANG_OK;
    }

    if (uuid == ISlangUnknown::getTypeGuid() && uuid == ICompileRequest::getTypeGuid())
    {
        addReference();
        *outObject = static_cast<slang::ICompileRequest*>(this);
        return SLANG_OK;
    }

    return SLANG_E_NO_INTERFACE;
}

void EndToEndCompileRequest::init()
{
    m_sink.setSourceManager(m_linkage->getSourceManager());

    m_writers = new StdWriters;

    // Set all the default writers
    for (int i = 0; i < int(WriterChannel::CountOf); ++i)
    {
        setWriter(WriterChannel(i), nullptr);
    }

    m_frontEndReq = new FrontEndCompileRequest(getLinkage(), m_writers, getSink());

    m_backEndReq = new BackEndCompileRequest(getLinkage(), getSink());
}

SlangResult EndToEndCompileRequest::executeActionsInner()
{
    // If no code-generation target was specified, then try to infer one from the source language,
    // just to make sure we can do something reasonable when invoked from the command line.
    //
    // TODO: This logic should be moved into `options.cpp` or somewhere else
    // specific to the command-line tool.
    //
    if (getLinkage()->targets.getCount() == 0)
    {
        auto language = inferSourceLanguage(getFrontEndReq());
        switch (language)
        {
        case SourceLanguage::HLSL:
            getLinkage()->addTarget(CodeGenTarget::DXBytecode);
            break;

        case SourceLanguage::GLSL:
            getLinkage()->addTarget(CodeGenTarget::SPIRV);
            break;

        default:
            break;
        }
    }

    // We only do parsing and semantic checking if we *aren't* doing
    // a pass-through compilation.
    //
    if (m_passThrough == PassThroughMode::None)
    {
        SLANG_RETURN_ON_FAIL(getFrontEndReq()->executeActionsInner());
    }

    if (getFrontEndReq()->outputPreprocessor)
    {
        return SLANG_OK;
    }

    // If command line specifies to skip codegen, we exit here.
    // Note: this is a debugging option.
    //
    if (m_shouldSkipCodegen ||
        ((getFrontEndReq()->compileFlags & SLANG_COMPILE_FLAG_NO_CODEGEN) != 0))
    {
        // We will use the program (and matching layout information)
        // that was computed in the front-end for all subsequent
        // reflection queries, etc.
        //
        m_specializedGlobalComponentType = getUnspecializedGlobalComponentType();
        m_specializedGlobalAndEntryPointsComponentType = getUnspecializedGlobalAndEntryPointsComponentType();
        m_specializedEntryPoints = getFrontEndReq()->getUnspecializedEntryPoints();

        SLANG_RETURN_ON_FAIL(maybeCreateContainer());
        SLANG_RETURN_ON_FAIL(maybeWriteContainer(m_containerOutputPath));

        return SLANG_OK;
    }

    // If codegen is enabled, we need to move along to
    // apply any generic specialization that the user asked for.
    //
    if (m_passThrough == PassThroughMode::None)
    {
        m_specializedGlobalComponentType = createSpecializedGlobalComponentType(this);
        if (getSink()->getErrorCount() != 0)
            return SLANG_FAIL;

        m_specializedGlobalAndEntryPointsComponentType = createSpecializedGlobalAndEntryPointsComponentType(
            this,
            m_specializedEntryPoints);
        if (getSink()->getErrorCount() != 0)
            return SLANG_FAIL;

        // For each code generation target, we will generate specialized
        // parameter binding information (taking global generic
        // arguments into account at this time).
        //
        for (auto targetReq : getLinkage()->targets)
        {
            auto targetProgram = m_specializedGlobalAndEntryPointsComponentType->getTargetProgram(targetReq);
            targetProgram->getOrCreateLayout(getSink());
        }
        if (getSink()->getErrorCount() != 0)
            return SLANG_FAIL;
    }
    else
    {
        // We need to create dummy `EntryPoint` objects
        // to make sure that the logic in `generateOutput`
        // sees something worth processing.
        //
        List<RefPtr<ComponentType>> dummyEntryPoints;
        for(auto entryPointReq : getFrontEndReq()->getEntryPointReqs())
        {
            RefPtr<EntryPoint> dummyEntryPoint = EntryPoint::createDummyForPassThrough(
                getLinkage(),
                entryPointReq->getName(),
                entryPointReq->getProfile());

            dummyEntryPoints.add(dummyEntryPoint);
        }

        RefPtr<ComponentType> composedProgram = CompositeComponentType::create(
            getLinkage(),
            dummyEntryPoints);

        m_specializedGlobalComponentType = getUnspecializedGlobalComponentType();
        m_specializedGlobalAndEntryPointsComponentType = composedProgram;
        m_specializedEntryPoints = getFrontEndReq()->getUnspecializedEntryPoints();
    }

    // Generate output code, in whatever format was requested
    getBackEndReq()->setProgram(getSpecializedGlobalAndEntryPointsComponentType());
    generateOutput(this);
    if (getSink()->getErrorCount() != 0)
        return SLANG_FAIL;

    return SLANG_OK;
}

// Act as expected of the API-based compiler
SlangResult EndToEndCompileRequest::executeActions()
{
    SlangResult res = executeActionsInner();

    m_diagnosticOutput = getSink()->outputBuffer.ProduceString();
    return res;
}

int FrontEndCompileRequest::addTranslationUnit(SourceLanguage language, Name* moduleName)
{
    if (!moduleName)
    {
        // We want to ensure that symbols defined in different translation
        // units get unique mangled names, so that we can, e.g., tell apart
        // a `main()` function in `vertex.hlsl` and a `main()` in `fragment.hlsl`,
        // even when they are being compiled together.
        //
        String generatedName = "tu";
        generatedName.append(translationUnits.getCount());
        moduleName = getNamePool()->getName(generatedName);
    }

    RefPtr<TranslationUnitRequest> translationUnit = new TranslationUnitRequest(this);
    translationUnit->compileRequest = this;
    translationUnit->sourceLanguage = SourceLanguage(language);

    translationUnit->moduleName = moduleName;

    return addTranslationUnit(translationUnit);
}

int FrontEndCompileRequest::addTranslationUnit(TranslationUnitRequest* translationUnit)
{
    Index result = translationUnits.getCount();
    translationUnits.add(translationUnit);
    return (int) result;
}


void FrontEndCompileRequest::addTranslationUnitSourceFile(
    int             translationUnitIndex,
    SourceFile*     sourceFile)
{
    translationUnits[translationUnitIndex]->addSourceFile(sourceFile);
}

void FrontEndCompileRequest::addTranslationUnitSourceBlob(
    int             translationUnitIndex,
    String const&   path,
    ISlangBlob*     sourceBlob)
{
    // The path specified may or may not be a file path - mark as being constructed 'FromString'.
    SourceFile* sourceFile = getSourceManager()->createSourceFileWithBlob(PathInfo::makeFromString(path), sourceBlob);
    
    addTranslationUnitSourceFile(translationUnitIndex, sourceFile);
}

void FrontEndCompileRequest::addTranslationUnitSourceString(
    int             translationUnitIndex,
    String const&   path,
    String const&   source)
{
    // The path specified may or may not be a file path - mark as being constructed 'FromString'.
    SourceFile* sourceFile = getSourceManager()->createSourceFileWithString(PathInfo::makeFromString(path), source);

    addTranslationUnitSourceFile(translationUnitIndex, sourceFile);
}

void FrontEndCompileRequest::addTranslationUnitSourceFile(
    int             translationUnitIndex,
    String const&   path)
{
    // TODO: We need to consider whether a relative `path` should cause
    // us to look things up using the registered search paths.
    //
    // This behavior wouldn't make sense for command-line invocations
    // of `slangc`, but at least one API user wondered by the search
    // paths were not taken into account by this function.
    //

    PathInfo pathInfo;

    ComPtr<ISlangBlob> sourceBlob;
    SlangResult result = loadFile(path, pathInfo, sourceBlob.writeRef());
    if(SLANG_FAILED(result))
    {
        // Emit a diagnostic!
        getSink()->diagnose(
            SourceLoc(),
            Diagnostics::cannotOpenFile,
            path);
        return;
    }

    // Was loaded from the specified path
    SourceFile* sourceFile = getSourceManager()->createSourceFileWithBlob(pathInfo, sourceBlob);
    addTranslationUnitSourceFile(translationUnitIndex, sourceFile);
}

int FrontEndCompileRequest::addEntryPoint(
    int                     translationUnitIndex,
    String const&           name,
    Profile                 entryPointProfile)
{
    auto translationUnitReq = translationUnits[translationUnitIndex];

    Index result = m_entryPointReqs.getCount();

    RefPtr<FrontEndEntryPointRequest> entryPointReq = new FrontEndEntryPointRequest(
        this,
        translationUnitIndex,
        getNamePool()->getName(name),
        entryPointProfile);

    m_entryPointReqs.add(entryPointReq);
//    translationUnitReq->entryPoints.Add(entryPointReq);

    return int(result);
}

int EndToEndCompileRequest::addEntryPoint(
    int                     translationUnitIndex,
    String const&           name,
    Profile                 entryPointProfile,
    List<String> const &    genericTypeNames)
{
    getFrontEndReq()->addEntryPoint(translationUnitIndex, name, entryPointProfile);

    EntryPointInfo entryPointInfo;
    for (auto typeName : genericTypeNames)
        entryPointInfo.specializationArgStrings.add(typeName);

    Index result = m_entryPoints.getCount();
    m_entryPoints.add(_Move(entryPointInfo));
    return (int) result;
}

UInt Linkage::addTarget(
    CodeGenTarget   target)
{
    RefPtr<TargetRequest> targetReq = new TargetRequest(this, target);

    Index result = targets.getCount();
    targets.add(targetReq);
    return (int) result;
}

void Linkage::loadParsedModule(
    RefPtr<FrontEndCompileRequest>  compileRequest,
    RefPtr<TranslationUnitRequest>  translationUnit,
    Name*                           name,
    const PathInfo&                 pathInfo)
{
    // Note: we add the loaded module to our name->module listing
    // before doing semantic checking, so that if it tries to
    // recursively `import` itself, we can detect it.
    //
    RefPtr<Module> loadedModule = translationUnit->getModule();

    // Get a path
    String mostUniqueIdentity = pathInfo.getMostUniqueIdentity();
    SLANG_ASSERT(mostUniqueIdentity.getLength() > 0);

    mapPathToLoadedModule.Add(mostUniqueIdentity, loadedModule);
    mapNameToLoadedModules.Add(name, loadedModule);

    auto sink = translationUnit->compileRequest->getSink();

    int errorCountBefore = sink->getErrorCount();
    compileRequest->checkAllTranslationUnits();
    int errorCountAfter = sink->getErrorCount();

    if (errorCountAfter != errorCountBefore)
    {
        // There must have been an error in the loaded module.
    }
    else
    {
        // If we didn't run into any errors, then try to generate
        // IR code for the imported module.
        SLANG_ASSERT(errorCountAfter == 0);
        loadedModule->setIRModule(generateIRForTranslationUnit(getASTBuilder(), translationUnit));
    }
    loadedModulesList.add(loadedModule);
}

Module* Linkage::loadModule(String const& name)
{
    // TODO: We either need to have a diagnostics sink
    // get passed into this operation, or associate
    // one with the linkage.
    //
    DiagnosticSink* sink = nullptr;
    return findOrImportModule(
        getNamePool()->getName(name),
        SourceLoc(),
        sink);
}

void Linkage::_diagnoseErrorInImportedModule(
    DiagnosticSink*     sink)
{
    for(auto info = m_modulesBeingImported; info; info = info->next)
    {
            sink->diagnose(info->importLoc, Diagnostics::errorInImportedModule, info->name);
    }
    sink->diagnose(SourceLoc(), Diagnostics::complationCeased);
}

RefPtr<Module> Linkage::loadModule(
    Name*               name,
    const PathInfo&     filePathInfo,
    ISlangBlob*         sourceBlob, 
    SourceLoc const&    srcLoc,
    DiagnosticSink*     sink)
{
    RefPtr<FrontEndCompileRequest> frontEndReq = new FrontEndCompileRequest(this, nullptr, sink);

    RefPtr<TranslationUnitRequest> translationUnit = new TranslationUnitRequest(frontEndReq);
    translationUnit->compileRequest = frontEndReq;
    translationUnit->moduleName = name;
    translationUnit->sourceLanguage = SourceLanguage::Slang;

    frontEndReq->addTranslationUnit(translationUnit);

    auto module = translationUnit->getModule();

    ModuleBeingImportedRAII moduleBeingImported(
        this,
        module,
        name,
        srcLoc);

    // Create with the 'friendly' name
    SourceFile* sourceFile = getSourceManager()->createSourceFileWithBlob(filePathInfo, sourceBlob);
    
    translationUnit->addSourceFile(sourceFile);

    int errorCountBefore = sink->getErrorCount();
    frontEndReq->parseTranslationUnit(translationUnit);
    int errorCountAfter = sink->getErrorCount();

    if( errorCountAfter != errorCountBefore )
    {
        _diagnoseErrorInImportedModule(sink);
    }
    if (errorCountAfter)
    {
        // Something went wrong during the parsing, so we should bail out.
        return nullptr;
    }

    loadParsedModule(
        frontEndReq,
        translationUnit,
        name,
        filePathInfo);

    errorCountAfter = sink->getErrorCount();

    if (errorCountAfter != errorCountBefore)
    {
        _diagnoseErrorInImportedModule(sink);
        // Something went wrong during the parsing, so we should bail out.
        return nullptr;
    }

    return module;
}

bool Linkage::isBeingImported(Module* module)
{
    for(auto ii = m_modulesBeingImported; ii; ii = ii->next)
    {
        if(module == ii->module)
            return true;
    }
    return false;
}

RefPtr<Module> Linkage::findOrImportModule(
    Name*               name,
    SourceLoc const&    loc,
    DiagnosticSink*     sink)
{
    // Have we already loaded a module matching this name?
    //
    RefPtr<LoadedModule> loadedModule;
    if (mapNameToLoadedModules.TryGetValue(name, loadedModule))
    {
        // If the map shows a null module having been loaded,
        // then that means there was a prior load attempt,
        // but it failed, so we won't bother trying again.
        //
        if (!loadedModule)
            return nullptr;

        // If state shows us that the module is already being
        // imported deeper on the call stack, then we've
        // hit a recursive case, and that is an error.
        //
        if(isBeingImported(loadedModule))
        {
            // We seem to be in the middle of loading this module
            sink->diagnose(loc, Diagnostics::recursiveModuleImport, name);
            return nullptr;
        }

        return loadedModule;
    }

    // Derive a file name for the module, by taking the given
    // identifier, replacing all occurrences of `_` with `-`,
    // and then appending `.slang`.
    //
    // For example, `foo_bar` becomes `foo-bar.slang`.

    StringBuilder sb;
    for (auto c : getText(name))
    {
        if (c == '_')
            c = '-';

        sb.Append(c);
    }
    sb.Append(".slang");

    String fileName = sb.ProduceString();

    // Next, try to find the file of the given name,
    // using our ordinary include-handling logic.

    IncludeSystem includeSystem(&searchDirectories, getFileSystemExt(), getSourceManager());

    // Get the original path info
    PathInfo pathIncludedFromInfo = getSourceManager()->getPathInfo(loc, SourceLocType::Actual);
    PathInfo filePathInfo;

    // We have to load via the found path - as that is how file was originally loaded 
    if (SLANG_FAILED(includeSystem.findFile(fileName, pathIncludedFromInfo.foundPath, filePathInfo)))
    {
        sink->diagnose(loc, Diagnostics::cannotFindFile, fileName);
        mapNameToLoadedModules[name] = nullptr;
        return nullptr;
    }

    // Maybe this was loaded previously at a different relative name?
    if (mapPathToLoadedModule.TryGetValue(filePathInfo.getMostUniqueIdentity(), loadedModule))
        return loadedModule;

    // Try to load it
    ComPtr<ISlangBlob> fileContents;
    if(SLANG_FAILED(includeSystem.loadFile(filePathInfo, fileContents)))
    {
        sink->diagnose(loc, Diagnostics::cannotOpenFile, fileName);
        mapNameToLoadedModules[name] = nullptr;
        return nullptr;
    }

    // We've found a file that we can load for the given module, so
    // go ahead and perform the module-load action
    return loadModule(
        name,
        filePathInfo,
        fileContents,
        loc,
        sink);
}

//
// ModuleDependencyList
//

void ModuleDependencyList::addDependency(Module* module)
{
    // If we depend on a module, then we depend on everything it depends on.
    //
    // Note: We are processing these sub-depenencies before adding the
    // `module` itself, so that in the common case a module will always
    // appear *after* everything it depends on.
    //
    // However, this rule is being violated in the compiler right now because
    // the modules for hte top-level translation units of a compile request
    // will be added to the list first (using `addLeafDependency`) to
    // maintain compatibility with old behavior. This may be fixed later.
    //
    for(auto subDependency : module->getModuleDependencyList())
    {
        _addDependency(subDependency);
    }
    _addDependency(module);
}

void ModuleDependencyList::addLeafDependency(Module* module)
{
    _addDependency(module);
}

void ModuleDependencyList::_addDependency(Module* module)
{
    if(m_moduleSet.Contains(module))
        return;

    m_moduleList.add(module);
    m_moduleSet.Add(module);
}

//
// FilePathDependencyList
//

void FilePathDependencyList::addDependency(String const& path)
{
    if(m_filePathSet.Contains(path))
        return;

    m_filePathList.add(path);
    m_filePathSet.Add(path);
}

void FilePathDependencyList::addDependency(Module* module)
{
    for(auto& path : module->getFilePathDependencyList())
    {
        addDependency(path);
    }
}



//
// Module
//

Module::Module(Linkage* linkage, ASTBuilder* astBuilder)
    : ComponentType(linkage)
    , m_mangledExportPool(StringSlicePool::Style::Empty)
{
    if (astBuilder)
    {
        m_astBuilder = astBuilder;
    }
    else
    {
        m_astBuilder = new ASTBuilder(linkage->getASTBuilder()->getSharedASTBuilder(), "Module");
    }

    addModuleDependency(this);
}

ISlangUnknown* Module::getInterface(const Guid& guid)
{
    if(guid == IModule::getTypeGuid())
        return asExternal(this);
    return Super::getInterface(guid);
}

void Module::addModuleDependency(Module* module)
{
    m_moduleDependencyList.addDependency(module);
    m_filePathDependencyList.addDependency(module);
}

void Module::addFilePathDependency(String const& path)
{
    m_filePathDependencyList.addDependency(path);
}

void Module::setModuleDecl(ModuleDecl* moduleDecl)
{
    m_moduleDecl = moduleDecl;
}

RefPtr<EntryPoint> Module::findEntryPointByName(UnownedStringSlice const& name)
{
    // TODO: We should consider having this function be expanded to be able
    // to look up and validate possible entry-point functions in teh module
    // even if they were not marked with `[shader(...)]` in the source code.
    //
    // With such a change the function would probably need to accept a stage
    // to use and a sink to write validation errors to.

    for(auto entryPoint : m_entryPoints)
    {
        if(entryPoint->getName()->text.getUnownedSlice() == name)
            return entryPoint;
    }

    return nullptr;
}

void Module::_addEntryPoint(EntryPoint* entryPoint)
{
    m_entryPoints.add(entryPoint);
}

static bool _canExportDeclSymbol(ASTNodeType type)
{
    switch (type)
    {
        case ASTNodeType::ModuleDecl:
        case ASTNodeType::EmptyDecl:
        case ASTNodeType::NamespaceDecl:
        {
            return false;
        }
        default: break;
    }

    return true;
}

static bool _canRecurseExportSymbol(Decl* decl)
{
    if (as<FunctionDeclBase>(decl) ||
        as<ScopeDecl>(decl))
    {
        return false;
    }
    return true;
}

void Module::_processFindDeclsExportSymbolsRec(Decl* decl)
{
    if (_canExportDeclSymbol(decl->astNodeType))
    {
        // It's a reference to a declaration in another module, so first get the symbol name. 
        String mangledName = getMangledName(getASTBuilder(), decl);

        Index index = Index(m_mangledExportPool.add(mangledName));

        // TODO(JS): It appears that more than one entity might have the same mangled name.
        // So for now we ignore and just take the first one.
        if (index == m_mangledExportSymbols.getCount())
        {
            m_mangledExportSymbols.add(decl);
        }
    }

    if (!_canRecurseExportSymbol(decl))
    {
        // We don't need to recurse any further into this
        return;
    }

    // If it's a container process it's children
    if(auto containerDecl = as<ContainerDecl>(decl))
    {
        for (auto child : containerDecl->members)
        {
            _processFindDeclsExportSymbolsRec(child);
        }
    }

    // GenericDecl is also a container, so do subsequent test
    if (auto genericDecl = as<GenericDecl>(decl))
    {
        _processFindDeclsExportSymbolsRec(genericDecl->inner);
    }
}

NodeBase* Module::findExportFromMangledName(const UnownedStringSlice& slice)
{
    // Will be non zero if has been previously attempted
    if (m_mangledExportSymbols.getCount() == 0)
    {
        // Build up the exported mangled name list
        _processFindDeclsExportSymbolsRec(getModuleDecl());

        // If nothing found, mark that we have tried looking by making m_mangledExportSymbols.getCount() != 0
        if (m_mangledExportSymbols.getCount() == 0)
        {
            m_mangledExportSymbols.add(nullptr);
        }        
    }

    const Index index = m_mangledExportPool.findIndex(slice);
    return (index >= 0) ? m_mangledExportSymbols[index] : nullptr;
}

// ComponentType

ComponentType::ComponentType(Linkage* linkage)
    : m_linkage(linkage)
{}

ComponentType* asInternal(slang::IComponentType* inComponentType)
{
    // Note: we use a `queryInterface` here instead of just a `static_cast`
    // to ensure that the `IComponentType` we get is the preferred/canonical
    // one, which shares its address with the `ComponentType`.
    //
    // TODO: An alternative choice here would be to have a "magic" IID that
    // we pass into `queryInterface` that returns the `ComponentType` directly
    // (without even `addRef`-ing it).
    //
    ComPtr<slang::IComponentType> componentType;
    inComponentType->queryInterface(slang::IComponentType::getTypeGuid(), (void**) componentType.writeRef());
    return static_cast<ComponentType*>(componentType.get());
}

ISlangUnknown* ComponentType::getInterface(Guid const& guid)
{
    if(guid == ISlangUnknown::getTypeGuid()
        || guid == slang::IComponentType::getTypeGuid())
    {
        return static_cast<slang::IComponentType*>(this);
    }

    return nullptr;
}

SLANG_NO_THROW slang::ISession* SLANG_MCALL ComponentType::getSession()
{
    return m_linkage;
}

SLANG_NO_THROW slang::ProgramLayout* SLANG_MCALL ComponentType::getLayout(
    Int             targetIndex,
    slang::IBlob**  outDiagnostics)
{
    auto linkage = getLinkage();
    if(targetIndex < 0 || targetIndex >= linkage->targets.getCount())
        return nullptr;
    auto target = linkage->targets[targetIndex];

    DiagnosticSink sink(linkage->getSourceManager(), Lexer::sourceLocationLexer);
    auto programLayout = getTargetProgram(target)->getOrCreateLayout(&sink);
    sink.getBlobIfNeeded(outDiagnostics);

    return asExternal(programLayout);
}

SLANG_NO_THROW SlangResult SLANG_MCALL ComponentType::getEntryPointCode(
    SlangInt        entryPointIndex,
    Int             targetIndex,
    slang::IBlob**  outCode,
    slang::IBlob**  outDiagnostics)
{
    auto linkage = getLinkage();
    if(targetIndex < 0 || targetIndex >= linkage->targets.getCount())
        return SLANG_E_INVALID_ARG;
    auto target = linkage->targets[targetIndex];

    auto targetProgram = getTargetProgram(target);

    DiagnosticSink sink(linkage->getSourceManager(), Lexer::sourceLocationLexer);
    auto& entryPointResult = targetProgram->getOrCreateEntryPointResult(entryPointIndex, &sink);
    sink.getBlobIfNeeded(outDiagnostics);

    if(entryPointResult.format == ResultFormat::None )
        return SLANG_FAIL;

    ComPtr<ISlangBlob> blob;
    SLANG_RETURN_ON_FAIL(entryPointResult.getBlob(blob));
    *outCode = blob.detach();
    return SLANG_OK;
}

SLANG_NO_THROW SlangResult SLANG_MCALL ComponentType::getEntryPointHostCallable(
    int                     entryPointIndex,
    int                     targetIndex,
    ISlangSharedLibrary**   outSharedLibrary,
    slang::IBlob**          outDiagnostics)
{
    auto linkage = getLinkage();
    if(targetIndex < 0 || targetIndex >= linkage->targets.getCount())
        return SLANG_E_INVALID_ARG;
    auto target = linkage->targets[targetIndex];

    auto targetProgram = getTargetProgram(target);

    DiagnosticSink sink(linkage->getSourceManager(), Lexer::sourceLocationLexer);
    auto& entryPointResult = targetProgram->getOrCreateEntryPointResult(entryPointIndex, &sink);
    sink.getBlobIfNeeded(outDiagnostics);

    if(entryPointResult.format == ResultFormat::None )
        return SLANG_FAIL;

    ComPtr<ISlangSharedLibrary> sharedLibrary;
    SLANG_RETURN_ON_FAIL(entryPointResult.getSharedLibrary(sharedLibrary));

    *outSharedLibrary = sharedLibrary.detach();
    return SLANG_OK;
}

RefPtr<ComponentType> ComponentType::specialize(
    SpecializationArg const*    inSpecializationArgs,
    SlangInt                    specializationArgCount,
    DiagnosticSink*             sink)
{
    if(specializationArgCount == 0)
    {
        return this;
    }

    List<SpecializationArg> specializationArgs;
    specializationArgs.addRange(
        inSpecializationArgs,
        specializationArgCount);

    // We next need to validate that the specialization arguments
    // make sense, and also expand them to include any derived data
    // (e.g., interface conformance witnesses) that doesn't get
    // passed explicitly through the API interface.
    //
    RefPtr<SpecializationInfo> specializationInfo = _validateSpecializationArgs(
        specializationArgs.getBuffer(),
        specializationArgCount,
        sink);

    return new SpecializedComponentType(
        this,
        specializationInfo,
        specializationArgs,
        sink);
}

SLANG_NO_THROW SlangResult SLANG_MCALL ComponentType::specialize(
    slang::SpecializationArg const* specializationArgs,
    SlangInt                        specializationArgCount,
    slang::IComponentType**         outSpecializedComponentType,
    ISlangBlob**                    outDiagnostics)
{
    DiagnosticSink sink(getLinkage()->getSourceManager(), Lexer::sourceLocationLexer);

    // First let's check if the number of arguments given matches
    // the number of parameters that are present on this component type.
    //
    auto specializationParamCount = getSpecializationParamCount();
    if( specializationArgCount != specializationParamCount )
    {
        sink.diagnose(SourceLoc(), Diagnostics::mismatchSpecializationArguments,
            specializationParamCount,
            specializationArgCount);
        sink.getBlobIfNeeded(outDiagnostics);
        return SLANG_FAIL;
    }

    List<SpecializationArg> expandedArgs;
    for( Int aa = 0; aa < specializationArgCount; ++aa )
    {
        auto apiArg = specializationArgs[aa];

        SpecializationArg expandedArg;
        switch(apiArg.kind)
        {
        case slang::SpecializationArg::Kind::Type:
            expandedArg.val = asInternal(apiArg.type);
            break;

        default:
            sink.getBlobIfNeeded(outDiagnostics);
            return SLANG_FAIL;
        }
        expandedArgs.add(expandedArg);
    }

    auto specializedComponentType = specialize(
        expandedArgs.getBuffer(),
        expandedArgs.getCount(),
        &sink);

    sink.getBlobIfNeeded(outDiagnostics);

    *outSpecializedComponentType = specializedComponentType.detach();

    return SLANG_OK;
}

SLANG_NO_THROW SlangResult SLANG_MCALL
    ComponentType::renameEntryPoint(const char* newName, IComponentType** outEntryPoint)
{
    RefPtr<RenamedEntryPointComponentType> result =
        new RenamedEntryPointComponentType(this, newName);
    *outEntryPoint = result.detach();
    return SLANG_OK;
}

RefPtr<ComponentType> fillRequirements(
    ComponentType* inComponentType);

SLANG_NO_THROW SlangResult SLANG_MCALL ComponentType::link(
    slang::IComponentType**         outLinkedComponentType,
    ISlangBlob**                    outDiagnostics)
{
    // TODO: It should be possible for `fillRequirements` to fail,
    // in cases where we have a dependency that can't be automatically
    // resolved.
    //
    SLANG_UNUSED(outDiagnostics);

    auto linked = fillRequirements(this);
    if(!linked)
        return SLANG_FAIL;

    *outLinkedComponentType = ComPtr<slang::IComponentType>(linked).detach();
    return SLANG_OK;
}


    /// Visitor used by `ComponentType::enumerateModules`
struct EnumerateModulesVisitor : ComponentTypeVisitor
{
    EnumerateModulesVisitor(ComponentType::EnumerateModulesCallback callback, void* userData)
        : m_callback(callback)
        , m_userData(userData)
    {}

    ComponentType::EnumerateModulesCallback m_callback;
    void* m_userData;

    void visitEntryPoint(EntryPoint*, EntryPoint::EntryPointSpecializationInfo*) SLANG_OVERRIDE {}

    void visitRenamedEntryPoint(
        RenamedEntryPointComponentType* entryPoint,
        EntryPoint::EntryPointSpecializationInfo* specializationInfo) SLANG_OVERRIDE
    {
        entryPoint->getBase()->acceptVisitor(this, specializationInfo);
    }

    void visitModule(Module* module, Module::ModuleSpecializationInfo*) SLANG_OVERRIDE
    {
        m_callback(module, m_userData);
    }

    void visitComposite(CompositeComponentType* composite, CompositeComponentType::CompositeSpecializationInfo* specializationInfo) SLANG_OVERRIDE
    {
        visitChildren(composite, specializationInfo);
    }

    void visitSpecialized(SpecializedComponentType* specialized) SLANG_OVERRIDE
    {
        visitChildren(specialized);
    }

    void visitTypeConformance(TypeConformance* conformance) SLANG_OVERRIDE
    {
        SLANG_UNUSED(conformance);
    }
};


void ComponentType::enumerateModules(EnumerateModulesCallback callback, void* userData)
{
    EnumerateModulesVisitor visitor(callback, userData);
    acceptVisitor(&visitor, nullptr);
}

    /// Visitor used by `ComponentType::enumerateIRModules`
struct EnumerateIRModulesVisitor : ComponentTypeVisitor
{
    EnumerateIRModulesVisitor(ComponentType::EnumerateIRModulesCallback callback, void* userData)
        : m_callback(callback)
        , m_userData(userData)
    {}

    ComponentType::EnumerateIRModulesCallback m_callback;
    void* m_userData;

    void visitEntryPoint(EntryPoint*, EntryPoint::EntryPointSpecializationInfo*) SLANG_OVERRIDE {}

    void visitRenamedEntryPoint(
        RenamedEntryPointComponentType* entryPoint,
        EntryPoint::EntryPointSpecializationInfo* specializationInfo) SLANG_OVERRIDE
    {
        entryPoint->getBase()->acceptVisitor(this, specializationInfo);
    }

    void visitModule(Module* module, Module::ModuleSpecializationInfo*) SLANG_OVERRIDE
    {
        m_callback(module->getIRModule(), m_userData);
    }

    void visitComposite(CompositeComponentType* composite, CompositeComponentType::CompositeSpecializationInfo* specializationInfo) SLANG_OVERRIDE
    {
        visitChildren(composite, specializationInfo);
    }

    void visitSpecialized(SpecializedComponentType* specialized) SLANG_OVERRIDE
    {
        visitChildren(specialized);

        m_callback(specialized->getIRModule(), m_userData);
    }

    void visitTypeConformance(TypeConformance* conformance) SLANG_OVERRIDE
    {
        m_callback(conformance->getIRModule(), m_userData);
    }
};

void ComponentType::enumerateIRModules(EnumerateIRModulesCallback callback, void* userData)
{
    EnumerateIRModulesVisitor visitor(callback, userData);
    acceptVisitor(&visitor, nullptr);
}

//
// CompositeComponentType
//

RefPtr<ComponentType> CompositeComponentType::create(
    Linkage*                            linkage,
    List<RefPtr<ComponentType>> const&  childComponents)
{
    // TODO: We should ideally be caching the results of
    // composition on the `linkage`, so that if we get
    // asked for the same composite again later we re-use
    // it rather than re-create it.
    //
    // Similarly, we might want to do some amount of
    // work to "canonicalize" the input for composition.
    // E.g., if the user does:
    //
    //    X = compose(A,B);
    //    Y = compose(C,D);
    //    Z = compose(X,Y);
    //
    //    W = compose(A, B, C, D);
    //
    // Then there is no observable difference between
    // Z and W, so we might prefer to have them be identical.

    // If there is only a single child, then we should
    // just return that child rather than create a dummy composite.
    //
    if( childComponents.getCount() == 1 )
    {
        return childComponents[0];
    }

    return new CompositeComponentType(linkage, childComponents);
}


CompositeComponentType::CompositeComponentType(
    Linkage*                            linkage,
    List<RefPtr<ComponentType>> const&  childComponents)
    : ComponentType(linkage)
    , m_childComponents(childComponents)
{
    HashSet<ComponentType*> requirementsSet;
    for(auto child : childComponents )
    {
        child->enumerateModules([&](Module* module)
        {
            requirementsSet.Add(module);
        });
    }

    for(auto child : childComponents )
    {
        auto childEntryPointCount = child->getEntryPointCount();
        for(Index cc = 0; cc < childEntryPointCount; ++cc)
        {
            m_entryPoints.add(child->getEntryPoint(cc));
            m_entryPointMangledNames.add(child->getEntryPointMangledName(cc));
            m_entryPointNameOverrides.add(child->getEntryPointNameOverride(cc));
        }

        auto childShaderParamCount = child->getShaderParamCount();
        for(Index pp = 0; pp < childShaderParamCount; ++pp)
        {
            m_shaderParams.add(child->getShaderParam(pp));
        }

        auto childSpecializationParamCount = child->getSpecializationParamCount();
        for(Index pp = 0; pp < childSpecializationParamCount; ++pp)
        {
            m_specializationParams.add(child->getSpecializationParam(pp));
        }

        for(auto module : child->getModuleDependencies())
        {
            m_moduleDependencyList.addDependency(module);
        }
        for(auto filePath : child->getFilePathDependencies())
        {
            m_filePathDependencyList.addDependency(filePath);
        }

        auto childRequirementCount = child->getRequirementCount();
        for(Index rr = 0; rr < childRequirementCount; ++rr)
        {
            auto childRequirement = child->getRequirement(rr);
            if(!requirementsSet.Contains(childRequirement))
            {
                requirementsSet.Add(childRequirement);
                m_requirements.add(childRequirement);
            }
        }
    }
}

Index CompositeComponentType::getEntryPointCount()
{
    return m_entryPoints.getCount();
}

RefPtr<EntryPoint> CompositeComponentType::getEntryPoint(Index index)
{
    return m_entryPoints[index];
}

String CompositeComponentType::getEntryPointMangledName(Index index)
{
    return m_entryPointMangledNames[index];
}

String CompositeComponentType::getEntryPointNameOverride(Index index)
{
    return m_entryPointNameOverrides[index];
}

Index CompositeComponentType::getShaderParamCount()
{
    return m_shaderParams.getCount();
}

ShaderParamInfo CompositeComponentType::getShaderParam(Index index)
{
    return m_shaderParams[index];
}

Index CompositeComponentType::getSpecializationParamCount()
{
    return m_specializationParams.getCount();
}

SpecializationParam const& CompositeComponentType::getSpecializationParam(Index index)
{
    return m_specializationParams[index];
}

Index CompositeComponentType::getRequirementCount()
{
    return m_requirements.getCount();
}

RefPtr<ComponentType> CompositeComponentType::getRequirement(Index index)
{
    return m_requirements[index];
}

List<Module*> const& CompositeComponentType::getModuleDependencies()
{
    return m_moduleDependencyList.getModuleList();
}

List<String> const& CompositeComponentType::getFilePathDependencies()
{
    return m_filePathDependencyList.getFilePathList();
}

void CompositeComponentType::acceptVisitor(ComponentTypeVisitor* visitor, SpecializationInfo* specializationInfo)
{
    visitor->visitComposite(this, as<CompositeSpecializationInfo>(specializationInfo));
}

RefPtr<ComponentType::SpecializationInfo> CompositeComponentType::_validateSpecializationArgsImpl(
    SpecializationArg const*    args,
    Index                       argCount,
    DiagnosticSink*             sink)
{
    SLANG_UNUSED(argCount);

    RefPtr<CompositeSpecializationInfo> specializationInfo = new CompositeSpecializationInfo();

    Index offset = 0;
    for(auto child : m_childComponents)
    {
        auto childParamCount = child->getSpecializationParamCount();
        SLANG_ASSERT(offset + childParamCount <= argCount);

        auto childInfo = child->_validateSpecializationArgs(
            args + offset,
            childParamCount,
            sink);

        specializationInfo->childInfos.add(childInfo);

        offset += childParamCount;
    }
    return specializationInfo;
}

//
// SpecializedComponentType
//

/// Utility type for collecting modules references by types/declarations
struct SpecializationArgModuleCollector : ComponentTypeVisitor
{
    HashSet<Module*> m_modulesSet;
    List<Module*> m_modulesList;

    void addModule(Module* module)
    {
        m_modulesList.add(module);
        m_modulesSet.Add(module);
    }

    void maybeAddModule(Module* module)
    {
        if(!module)
            return;
        if(m_modulesSet.Contains(module))
            return;

        addModule(module);
    }

    void collectReferencedModules(Decl* decl)
    {
        auto module = getModule(decl);
        maybeAddModule(module);
    }

    void collectReferencedModules(Substitutions* substitution)
    {
        if(auto genericSubst = as<GenericSubstitution>(substitution))
        {
            for(auto arg : genericSubst->args)
            {
                collectReferencedModules(arg);
            }
        }
    }

    void collectReferencedModules(SubstitutionSet const& substitutions)
    {
        for(auto subst = substitutions.substitutions; subst; subst = subst->outer)
        {
            collectReferencedModules(subst);
        }
    }

    void collectReferencedModules(DeclRefBase const& declRef)
    {
        collectReferencedModules(declRef.decl);
        collectReferencedModules(declRef.substitutions);
    }

    void collectReferencedModules(Type* type)
    {
        if(auto declRefType = as<DeclRefType>(type))
        {
            collectReferencedModules(declRefType->declRef);
        }

        // TODO: Handle non-decl-ref composite type cases
        // (e.g., function types).
    }

    void collectReferencedModules(Val* val)
    {
        if(auto type = as<Type>(val))
        {
            collectReferencedModules(type);
        }
        else if (auto declRefVal = as<GenericParamIntVal>(val))
        {
            collectReferencedModules(declRefVal->declRef);
        }

        // TODO: other cases of values that could reference
        // a declaration.
    }

    void collectReferencedModules(List<ExpandedSpecializationArg> const& args)
    {
        for(auto arg : args)
        {
            collectReferencedModules(arg.val);
            collectReferencedModules(arg.witness);
        }
    }

    //
    // ComponentTypeVisitor methods
    //

    void visitEntryPoint(EntryPoint* entryPoint, EntryPoint::EntryPointSpecializationInfo* specializationInfo) SLANG_OVERRIDE
    {
        SLANG_UNUSED(entryPoint);

        if(!specializationInfo)
            return;

        collectReferencedModules(specializationInfo->specializedFuncDeclRef);
        collectReferencedModules(specializationInfo->existentialSpecializationArgs);
    }

    void visitRenamedEntryPoint(
        RenamedEntryPointComponentType* entryPoint,
        EntryPoint::EntryPointSpecializationInfo* specializationInfo) SLANG_OVERRIDE
    {
        entryPoint->getBase()->acceptVisitor(this, specializationInfo);
    }

    void visitModule(Module* module, Module::ModuleSpecializationInfo* specializationInfo) SLANG_OVERRIDE
    {
        SLANG_UNUSED(module);

        if(!specializationInfo)
            return;

        for(auto arg : specializationInfo->genericArgs)
        {
            collectReferencedModules(arg.argVal);
        }
        collectReferencedModules(specializationInfo->existentialArgs);
    }

    void visitComposite(CompositeComponentType* composite, CompositeComponentType::CompositeSpecializationInfo* specializationInfo) SLANG_OVERRIDE
    {
        visitChildren(composite, specializationInfo);
    }

    void visitSpecialized(SpecializedComponentType* specialized) SLANG_OVERRIDE
    {
        visitChildren(specialized);
    }

    void visitTypeConformance(TypeConformance* conformance) SLANG_OVERRIDE
    {
        SLANG_UNUSED(conformance);
    }
};

SpecializedComponentType::SpecializedComponentType(
    ComponentType*                      base,
    ComponentType::SpecializationInfo*  specializationInfo,
    List<SpecializationArg> const&      specializationArgs,
    DiagnosticSink*                     sink)
    : ComponentType(base->getLinkage())
    , m_base(base)
    , m_specializationInfo(specializationInfo)
    , m_specializationArgs(specializationArgs)
{
    m_irModule = generateIRForSpecializedComponentType(this, sink);

    // We need to account for the fact that a specialized
    // entity like `myShader<SomeType>` needs to not only
    // depend on the module(s) that `myShader` depends on,
    // but also on any modules that `SomeType` depends on.
    //
    // We will set up a "collector" type that will be
    // used to build a list of these additional modules.
    //
    SpecializationArgModuleCollector moduleCollector;

    // We don't want to go adding additional requirements for
    // modules that the base component type already includes,
    // so we will add those to the set of modules in
    // the collector before we starting trying to add others.
    //
    base->enumerateModules([&](Module* module)
    {
        moduleCollector.m_modulesSet.Add(module);
    });

    // In order to collect the additional modules, we need
    // to inspect the specialization arguments and see what
    // they depend on.
    //
    // Naively, it seems like we'd just want to iterate
    // over `specializationArgs`, which gives the specialization
    // arguments as the user supplied them. However, such
    // an approach would have a subtle problem.
    //
    // If we have a generic entry point like:
    //
    //      // In module A
    //      myShader<T : IThing>
    //
    //
    // And the type `SomeType` that is being used as an argument doesn't
    // directly conform to `IThing`:
    //
    //      // In module B
    //      struct SomeType { ... }
    //
    // and the conformance of `SomeType` to `IThing` is
    // coming from yet another module:
    //
    //      // In module C
    //      import B;
    //      extension SomeType : IThing { ... }
    //
    // In this case, the specialized component for `myShader<SomeType>`
    // needs to depend on all of:
    //
    // * Module A, because it defines `myShader`
    // * Module B, because it defines `SomeType`
    // * Module C, because it defines the conformance `SomeType : IThing`
    //
    // We thus need to iterate over a form of the specialization
    // arguments that includes the "expanded" arguments like
    // interface conformance witnesses that got added during
    // semantic checking.
    //
    // The expanded arguments are being stored in the `specializationInfo`
    // today (for use by downstream code generation), and the easiest
    // way to walk that information and get to the leaf nodes where
    // the expanded arguments are stored is to apply a visitor to
    // the specialized component type we are in the middle of constructing.
    //
    moduleCollector.visitSpecialized(this);

    // Now that we've collected our additional information, we can
    // start to build up the final lists for the specialized component type.
    //
    // The starting point for our lists comes from the base component type.
    //
    m_moduleDependencies = base->getModuleDependencies();
    m_filePathDependencies = base->getFilePathDependencies();

    Index baseRequirementCount = base->getRequirementCount();
    for( Index r = 0; r < baseRequirementCount; r++ )
    {
        m_requirements.add(base->getRequirement(r));
    }

    // The specialized component type will need to have additional
    // dependencies and requirements based on the modules that
    // were collected when looking at the specialization arguments.

    // We want to avoid adding the same file path dependency more than once.
    //
    HashSet<String> filePathDependencySet;
    for(auto path : m_filePathDependencies)
        filePathDependencySet.Add(path);

    for(auto module : moduleCollector.m_modulesList)
    {
        // The specialized component type will have an open (unsatisfied)
        // requirement for each of the modules that its specialization
        // arguments need.
        //
        // Note: what this means in practice is that the component type
        // records that the given module(s) will need to be linked in
        // before final code can be generated, but it importantly
        // does not dictate the final placement of the parameters from
        // those modules in the layout.
        //
        m_requirements.add(module);

        // The speciialized component type will also have a dependency
        // on all the file paths that any of the modules involved in
        // it depend on (including those that are required but not
        // yet linked in).
        //
        // The file path information is what a client would need to
        // use to decide if kernel code is out of date compared to
        // source files, so we want to include anything that could
        // affect the validity of generated code.
        //
        for(auto path : module->getFilePathDependencies())
        {
            if(filePathDependencySet.Contains(path))
                continue;
            filePathDependencySet.Add(path);
            m_filePathDependencies.add(path);
        }

        // Finalyl we also add the module for the specialization arguments
        // to the list of modules that would be used for legacy lookup
        // operations where we need an implicit/default scope to use
        // and want it to be expansive.
        //
        // TODO: This stuff really isn't worth keeping around long
        // term, and we should ditch the entire "legacy lookup" idea.
        //
        m_moduleDependencies.add(module);
    }

    // The following is a bit of a hack.
    //
    // TODO: We should not need this hack any longer, since the
    // new approach to `switch`-based dynamic dispatch has made
    // the existing tagged-union support obsolete.
    //
    // Back-end code generation relies on us having computed layouts for all tagged
    // unions that end up being used in the code, which means we need a way to find
    // all such types that get used in a program (and the stuff it imports).
    //
    // For now we are assuming a tagged union type only comes into existence
    // as a (top-level) argument for a generic type parameter, so that we
    // can check for them here and cache them on the entry point.
    //
    // A longer-term strategy might need to consider any (tagged or untagged)
    // union types that get used inside of a module, and also take
    // those lists into account.
    //
    // An even longer-term strategy would be to allow type layout to
    // be performed on IR types, so taht we don't need to have front-end
    // code worrying about this stuff.
    // 
    for(auto arg : specializationArgs)
    {
        auto argType = as<Type>(arg.val);
        if(!argType)
            continue;

        auto taggedUnionType = as<TaggedUnionType>(argType);
        if(!taggedUnionType)
            continue;

        m_taggedUnionTypes.add(taggedUnionType);
    }

    // Because we are specializing shader code, the mangled entry
    // point names for this component type may be different than
    // for the base component type (e.g., the mangled name for `f<int>`
    // is different than that that of the generic `f` function
    // itself).
    //
    // We will compute the mangled names of all the entry points and
    // store them here, so that we don't have to do it on the fly.
    // Because the `ComponentType` structure is hierarchical, we
    // need to use a recursive visitor to compute the names,
    // and we will define that visitor locally:
    //
    struct EntryPointMangledNameCollector : ComponentTypeVisitor
    {
        List<String>* mangledEntryPointNames;
        List<String>* entryPointNameOverrides;

        void visitEntryPoint(EntryPoint* entryPoint, EntryPoint::EntryPointSpecializationInfo* specializationInfo)  SLANG_OVERRIDE
        {
            auto funcDeclRef = entryPoint->getFuncDeclRef();
            if(specializationInfo)
                funcDeclRef = specializationInfo->specializedFuncDeclRef;

            (*mangledEntryPointNames).add(getMangledName(m_astBuilder, funcDeclRef));
            (*entryPointNameOverrides).add(entryPoint->getEntryPointNameOverride(0));
        }

        void visitRenamedEntryPoint(
            RenamedEntryPointComponentType* entryPoint,
            EntryPoint::EntryPointSpecializationInfo* specializationInfo) SLANG_OVERRIDE
        {
            entryPoint->getBase()->acceptVisitor(this, specializationInfo);
            (*entryPointNameOverrides).getLast() = entryPoint->getEntryPointNameOverride(0);
        }

        void visitModule(Module*, Module::ModuleSpecializationInfo*) SLANG_OVERRIDE
        {}
        void visitComposite(CompositeComponentType* composite, CompositeComponentType::CompositeSpecializationInfo* specializationInfo) SLANG_OVERRIDE
        { visitChildren(composite, specializationInfo); }
        void visitSpecialized(SpecializedComponentType* specialized) SLANG_OVERRIDE
        { visitChildren(specialized); }
        void visitTypeConformance(TypeConformance* conformance) SLANG_OVERRIDE
        {
            SLANG_UNUSED(conformance);
        }
        EntryPointMangledNameCollector(ASTBuilder* astBuilder):
            m_astBuilder(astBuilder)
        {
        }
        ASTBuilder* m_astBuilder;
    };

    // With the visitor defined, we apply it to ourself to compute
    // and collect the mangled entry point names.
    //
    EntryPointMangledNameCollector collector(getLinkage()->getASTBuilder());
    collector.mangledEntryPointNames = &m_entryPointMangledNames;
    collector.entryPointNameOverrides = &m_entryPointNameOverrides;
    collector.visitSpecialized(this);
}

void SpecializedComponentType::acceptVisitor(ComponentTypeVisitor* visitor, SpecializationInfo* specializationInfo)
{
    SLANG_ASSERT(specializationInfo == nullptr);
    SLANG_UNUSED(specializationInfo);
    visitor->visitSpecialized(this);
}

Index SpecializedComponentType::getRequirementCount()
{
    return m_requirements.getCount();
}

RefPtr<ComponentType> SpecializedComponentType::getRequirement(Index index)
{
    return m_requirements[index];
}

String SpecializedComponentType::getEntryPointMangledName(Index index)
{
    return m_entryPointMangledNames[index];
}

String SpecializedComponentType::getEntryPointNameOverride(Index index)
{
    return m_entryPointNameOverrides[index];
}

// RenamedEntryPointComponentType

RenamedEntryPointComponentType::RenamedEntryPointComponentType(
    ComponentType* base, String newName)
    : ComponentType(base->getLinkage())
    , m_base(base)
    , m_entryPointNameOverride(newName)
{
}

void RenamedEntryPointComponentType::acceptVisitor(
    ComponentTypeVisitor* visitor, SpecializationInfo* specializationInfo)
{
    visitor->visitRenamedEntryPoint(
        this, as<EntryPoint::EntryPointSpecializationInfo>(specializationInfo));
}

void ComponentTypeVisitor::visitChildren(CompositeComponentType* composite, CompositeComponentType::CompositeSpecializationInfo* specializationInfo)
{
    auto childCount = composite->getChildComponentCount();
    for(Index ii = 0; ii < childCount; ++ii)
    {
        auto child = composite->getChildComponent(ii);
        auto childSpecializationInfo = specializationInfo
            ? specializationInfo->childInfos[ii]
            : nullptr;

        child->acceptVisitor(this, childSpecializationInfo);
    }
}

void ComponentTypeVisitor::visitChildren(SpecializedComponentType* specialized)
{
    specialized->getBaseComponentType()->acceptVisitor(this, specialized->getSpecializationInfo());
}

TargetProgram* ComponentType::getTargetProgram(TargetRequest* target)
{
    RefPtr<TargetProgram> targetProgram;
    if(!m_targetPrograms.TryGetValue(target, targetProgram))
    {
        targetProgram = new TargetProgram(this, target);
        m_targetPrograms[target] = targetProgram;
    }
    return targetProgram;
}

//
// TargetProgram
//

TargetProgram::TargetProgram(
    ComponentType*  componentType,
    TargetRequest*  targetReq)
    : m_program(componentType)
    , m_targetReq(targetReq)
{
    m_entryPointResults.setCount(componentType->getEntryPointCount());
}

//




Session* CompileRequestBase::getSession()
{
    return getLinkage()->getSessionImpl();
}

void Linkage::setFileSystem(ISlangFileSystem* inFileSystem)
{
    // Set the fileSystem
    m_fileSystem = inFileSystem;

    // Release what's there
    m_fileSystemExt.setNull();
    m_cacheFileSystem.setNull();

    // If nullptr passed in set up default 
    if (inFileSystem == nullptr)
    {
        m_cacheFileSystem = new Slang::CacheFileSystem(Slang::OSFileSystem::getExtSingleton());
        m_fileSystemExt = m_cacheFileSystem;
    }
    else
    {
        CacheFileSystem* cacheFileSystemPtr = nullptr;   
        inFileSystem->queryInterface(CacheFileSystem::getTypeGuid(), (void**)&cacheFileSystemPtr);
        if (cacheFileSystemPtr)
        {
            m_cacheFileSystem = cacheFileSystemPtr;
            m_fileSystemExt = cacheFileSystemPtr;
        }
        else 
        {
            if (m_requireCacheFileSystem)
            {
                m_cacheFileSystem = new Slang::CacheFileSystem(inFileSystem);
                m_fileSystemExt = m_cacheFileSystem;
            }
            else
            {
                // See if we have the full ISlangFileSystemExt interface, if we do just use it
                inFileSystem->queryInterface(ISlangFileSystemExt::getTypeGuid(), (void**)m_fileSystemExt.writeRef());

                // If not wrap with CacheFileSystem that emulates ISlangFileSystemExt from the ISlangFileSystem interface
                if (!m_fileSystemExt)
                {
                    // Construct a wrapper to emulate the extended interface behavior
                    m_cacheFileSystem = new Slang::CacheFileSystem(m_fileSystem);
                    m_fileSystemExt = m_cacheFileSystem;
                }
            }
        }
    }

    // Set the file system used on the source manager
    getSourceManager()->setFileSystemExt(m_fileSystemExt);
}

void Linkage::setRequireCacheFileSystem(bool requireCacheFileSystem)
{
    if (requireCacheFileSystem == m_requireCacheFileSystem)
    {
        return;
    }

    ComPtr<ISlangFileSystem> scopeFileSystem(m_fileSystem);
    m_requireCacheFileSystem = requireCacheFileSystem;

    setFileSystem(scopeFileSystem);
}

RefPtr<Module> findOrImportModule(
    Linkage*            linkage,
    Name*               name,
    SourceLoc const&    loc,
    DiagnosticSink*     sink)
{
    return linkage->findOrImportModule(name, loc, sink);
}

void Session::addBuiltinSource(
    Scope*                  scope,
    String const&           path,
    String const&           source)
{
    SourceManager* sourceManager = getBuiltinSourceManager();

    DiagnosticSink sink(sourceManager, Lexer::sourceLocationLexer);
    RefPtr<FrontEndCompileRequest> compileRequest = new FrontEndCompileRequest(
        m_builtinLinkage,
        nullptr, 
        &sink);
    compileRequest->m_isStandardLibraryCode = true;

    // Set the source manager on the sink
    sink.setSourceManager(sourceManager);
    // Make the linkage use the builtin source manager
    Linkage* linkage = compileRequest->getLinkage();
    linkage->setSourceManager(sourceManager);

    Name* moduleName = getNamePool()->getName(path);
    auto translationUnitIndex = compileRequest->addTranslationUnit(SourceLanguage::Slang, moduleName);

    compileRequest->addTranslationUnitSourceString(
        translationUnitIndex,
        path,
        source);

    SlangResult res = compileRequest->executeActionsInner();
    if (SLANG_FAILED(res))
    {
        char const* diagnostics = sink.outputBuffer.getBuffer();
        fprintf(stderr, "%s", diagnostics);

#ifdef _WIN32
        OutputDebugStringA(diagnostics);
#endif

        SLANG_UNEXPECTED("error in Slang standard library");
    }

    // Extract the AST for the code we just parsed
    auto module = compileRequest->translationUnits[translationUnitIndex]->getModule();
    auto moduleDecl = module->getModuleDecl();

    // Put in the loaded module map
    linkage->mapNameToLoadedModules.Add(moduleName, module);

    // Add the resulting code to the appropriate scope
    if (!scope->containerDecl)
    {
        // We are the first chunk of code to be loaded for this scope
        scope->containerDecl = moduleDecl;
    }
    else
    {
        // We need to create a new scope to link into the whole thing
        auto subScope = module->getASTBuilder()->create<Scope>();
        subScope->containerDecl = moduleDecl;
        subScope->nextSibling = scope->nextSibling;
        scope->nextSibling = subScope;
    }

    // We need to retain this AST so that we can use it in other code
    // (Note that the `Scope` type does not retain the AST it points to)
    stdlibModules.add(module);
}

Session::~Session()
{
    // destroy modules next
    stdlibModules = decltype(stdlibModules)();
}

}


/* !!!!!!!!!!!!!!!!!! EndToEndCompileRequestImpl !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! */

namespace Slang
{

void EndToEndCompileRequest::setFileSystem(ISlangFileSystem* fileSystem)
{
    getLinkage()->setFileSystem(fileSystem);
}

void EndToEndCompileRequest::setCompileFlags(SlangCompileFlags flags)
{
    getFrontEndReq()->compileFlags = flags;
}

void EndToEndCompileRequest::setDumpIntermediates(int enable)
{
    getBackEndReq()->shouldDumpIntermediates = (enable != 0);

    // Change all existing targets to use the new setting.
    auto linkage = getLinkage();
    for (auto& target : linkage->targets)
    {
        target->setDumpIntermediates(enable != 0);
    }
}

void EndToEndCompileRequest::setDumpIntermediatePrefix(const char* prefix)
{
    getBackEndReq()->m_dumpIntermediatePrefix = prefix;
}

void EndToEndCompileRequest::setLineDirectiveMode(SlangLineDirectiveMode mode)
{
    // This method is deprecated and user should call `setTargetLineDirectiveMode` instead.
    // We provide the implementation here for backward compatibility.
    // Targets added later will use `m_lineDirectiveMode`, so we update it to the new `mode`
    // set by the user.
    m_lineDirectiveMode = LineDirectiveMode(mode);

    // Change all existing targets to use the new mode.
    auto linkage = getLinkage();
    for (auto& target : linkage->targets)
        target->setLineDirectiveMode(m_lineDirectiveMode);
}

void EndToEndCompileRequest::setCommandLineCompilerMode()
{
    m_isCommandLineCompile = true;
}

void EndToEndCompileRequest::setCodeGenTarget(SlangCompileTarget target)
{
    auto linkage = getLinkage();
    linkage->targets.clear();
    linkage->addTarget(CodeGenTarget(target));
    linkage->targets[0]->setLineDirectiveMode(m_lineDirectiveMode);
}

int EndToEndCompileRequest::addCodeGenTarget(SlangCompileTarget target)
{
    int targetIndex = (int)getLinkage()->addTarget(CodeGenTarget(target));
    getLinkage()->targets[targetIndex]->setLineDirectiveMode(m_lineDirectiveMode);
    return targetIndex;
}

void EndToEndCompileRequest::setTargetProfile(int targetIndex, SlangProfileID profile)
{
    getLinkage()->targets[targetIndex]->setTargetProfile(Profile(profile));
}

void EndToEndCompileRequest::setTargetFlags(int targetIndex, SlangTargetFlags flags)
{
    getLinkage()->targets[targetIndex]->addTargetFlags(flags);
}

void EndToEndCompileRequest::setTargetForceGLSLScalarBufferLayout(int targetIndex, bool value)
{
    getLinkage()->targets[targetIndex]->setForceGLSLScalarBufferLayout(value);
}

void EndToEndCompileRequest::setTargetFloatingPointMode(int targetIndex, SlangFloatingPointMode  mode)
{
    getLinkage()->targets[targetIndex]->setFloatingPointMode(FloatingPointMode(mode));
}

void EndToEndCompileRequest::setMatrixLayoutMode(SlangMatrixLayoutMode mode)
{
    getLinkage()->setMatrixLayoutMode(mode);
}

void EndToEndCompileRequest::setTargetMatrixLayoutMode(int targetIndex, SlangMatrixLayoutMode  mode)
{
    SLANG_UNUSED(targetIndex);
    setMatrixLayoutMode(mode);
}

void EndToEndCompileRequest::setTargetLineDirectiveMode(
    SlangInt targetIndex,
    SlangLineDirectiveMode mode)
{
    getLinkage()->targets[targetIndex]->setLineDirectiveMode(LineDirectiveMode(mode));
}

SlangResult EndToEndCompileRequest::addTargetCapability(SlangInt targetIndex, SlangCapabilityID capability)
{
    auto& targets = getLinkage()->targets;
    if(targetIndex < 0 || targetIndex >= targets.getCount())
        return SLANG_E_INVALID_ARG;
    targets[targetIndex]->addCapability(CapabilityAtom(capability));
    return SLANG_OK;
}

void EndToEndCompileRequest::setDebugInfoLevel(SlangDebugInfoLevel level)
{
    getLinkage()->debugInfoLevel = DebugInfoLevel(level);
}

void EndToEndCompileRequest::setOptimizationLevel(SlangOptimizationLevel level)
{
    getLinkage()->optimizationLevel = OptimizationLevel(level);
}

void EndToEndCompileRequest::setOutputContainerFormat(SlangContainerFormat format)
{
    m_containerFormat = ContainerFormat(format);
}

void EndToEndCompileRequest::setPassThrough(SlangPassThrough inPassThrough)
{
    m_passThrough = PassThroughMode(inPassThrough);
}

void EndToEndCompileRequest::setDiagnosticCallback(SlangDiagnosticCallback callback, void const* userData)
{
    ComPtr<ISlangWriter> writer(new CallbackWriter(callback, userData, WriterFlag::IsConsole));
    setWriter(WriterChannel::Diagnostic, writer);
}

void EndToEndCompileRequest::setWriter(SlangWriterChannel chan, ISlangWriter* writer)
{
    setWriter(WriterChannel(chan), writer);
}

ISlangWriter* EndToEndCompileRequest::getWriter(SlangWriterChannel chan)
{
    return getWriter(WriterChannel(chan));
}

void EndToEndCompileRequest::addSearchPath(const char* path)
{
    getLinkage()->addSearchPath(path);
}

void EndToEndCompileRequest::addPreprocessorDefine(const char* key, const char* value)
{
    getLinkage()->addPreprocessorDefine(key, value);
}

char const* EndToEndCompileRequest::getDiagnosticOutput()
{
    return m_diagnosticOutput.begin();
}

SlangResult EndToEndCompileRequest::getDiagnosticOutputBlob(ISlangBlob** outBlob)   
{
    if (!outBlob) return SLANG_E_INVALID_ARG;

    if (!m_diagnosticOutputBlob)
    {
        m_diagnosticOutputBlob = StringUtil::createStringBlob(m_diagnosticOutput);
    }

    ComPtr<ISlangBlob> resultBlob = m_diagnosticOutputBlob;
    *outBlob = resultBlob.detach();
    return SLANG_OK;
}

int EndToEndCompileRequest::addTranslationUnit(SlangSourceLanguage language, char const* inName)
{
    auto frontEndReq = getFrontEndReq();
    NamePool* namePool = frontEndReq->getNamePool();

    // Work out a module name. Can be nullptr if so will generate a name
    Name* moduleName = inName ? namePool->getName(inName) : frontEndReq->m_defaultModuleName;

    // If moduleName is nullptr a name will be generated
    return frontEndReq->addTranslationUnit(Slang::SourceLanguage(language), moduleName);
}

void EndToEndCompileRequest::setDefaultModuleName(const char* defaultModuleName)
{
    auto frontEndReq = getFrontEndReq();
    NamePool* namePool = frontEndReq->getNamePool();
    frontEndReq->m_defaultModuleName = namePool->getName(defaultModuleName);
}

SlangResult _addLibraryReference(EndToEndCompileRequest* req, Stream* stream)
{
    // Load up the module
    RiffContainer riffContainer;
    SLANG_RETURN_ON_FAIL(RiffUtil::read(stream, riffContainer));

    auto linkage = req->getLinkage();

    // TODO(JS): May be better to have a ITypeComponent that encapsulates a collection of modules
    // For now just add to the linkage

    {
        SerialContainerData containerData;

        SerialContainerUtil::ReadOptions options;
        options.namePool = req->getNamePool();
        options.session = req->getSession();
        options.sharedASTBuilder = linkage->getASTBuilder()->getSharedASTBuilder();
        options.sourceManager = linkage->getSourceManager();
        options.linkage = req->getLinkage();
        options.sink = req->getSink();

        SLANG_RETURN_ON_FAIL(SerialContainerUtil::read(&riffContainer, options, containerData));

        for (const auto& module : containerData.modules)
        {
            // If the irModule is set, add it
            if (module.irModule)
            {
                linkage->m_libModules.add(module.irModule);
            }
        }

        FrontEndCompileRequest* frontEndRequest = req->getFrontEndReq();

        for (const auto& entryPoint : containerData.entryPoints)
        {
            FrontEndCompileRequest::ExtraEntryPointInfo dst;
            dst.mangledName = entryPoint.mangledName;
            dst.name = entryPoint.name;
            dst.profile = entryPoint.profile;

            // Add entry point
            frontEndRequest->m_extraEntryPoints.add(dst);
        }
    }

    return SLANG_OK;
}

SlangResult EndToEndCompileRequest::addLibraryReference(const void* libData, size_t libDataSize)
{
    // We need to deserialize and add the modules
    MemoryStreamBase fileStream(FileAccess::Read, libData, libDataSize);
    return _addLibraryReference(this, &fileStream);
}

void EndToEndCompileRequest::addTranslationUnitPreprocessorDefine(int translationUnitIndex, const char* key, const char* value)
{
    getFrontEndReq()->translationUnits[translationUnitIndex]->preprocessorDefinitions[key] = value;
}

void EndToEndCompileRequest::addTranslationUnitSourceFile(int translationUnitIndex, char const* path)
{
    auto frontEndReq = getFrontEndReq();
    if (!path) return;
    if (translationUnitIndex < 0) return;
    if (Index(translationUnitIndex) >= frontEndReq->translationUnits.getCount()) return;

    frontEndReq->addTranslationUnitSourceFile(translationUnitIndex, path);
}

void EndToEndCompileRequest::addTranslationUnitSourceString(int translationUnitIndex, char const* path, char const* source)
{
    if (!source) return;
    addTranslationUnitSourceStringSpan(translationUnitIndex, path, source, source + strlen(source));
}

void EndToEndCompileRequest::addTranslationUnitSourceStringSpan(int translationUnitIndex, char const* path, char const* sourceBegin, char const* sourceEnd)
{
    auto frontEndReq = getFrontEndReq();
    if (!sourceBegin) return;
    if (translationUnitIndex < 0) return;
    if (Index(translationUnitIndex) >= frontEndReq->translationUnits.getCount()) return;

    if (!path) path = "";

    frontEndReq->addTranslationUnitSourceString(translationUnitIndex, path, UnownedStringSlice(sourceBegin, sourceEnd));
}

void EndToEndCompileRequest::addTranslationUnitSourceBlob(int translationUnitIndex, char const* path, ISlangBlob* sourceBlob)
{
    auto frontEndReq = getFrontEndReq();
    if (!sourceBlob) return;
    if (translationUnitIndex < 0) return;
    if (Slang::Index(translationUnitIndex) >= frontEndReq->translationUnits.getCount()) return;

    if (!path) path = "";

    frontEndReq->addTranslationUnitSourceBlob(translationUnitIndex, path, sourceBlob);
}


int EndToEndCompileRequest::addEntryPoint(int translationUnitIndex, char const* name, SlangStage stage)
{
    return addEntryPointEx(translationUnitIndex, name, stage, 0, nullptr);
}

int EndToEndCompileRequest::addEntryPointEx(int translationUnitIndex, char const* name, SlangStage stage, int genericParamTypeNameCount, char const** genericParamTypeNames)
{
    auto frontEndReq = getFrontEndReq();
    if (!name) return -1;
    if (translationUnitIndex < 0) return -1;
    if (Index(translationUnitIndex) >= frontEndReq->translationUnits.getCount()) return -1;

    List<String> typeNames;
    for (int i = 0; i < genericParamTypeNameCount; i++)
        typeNames.add(genericParamTypeNames[i]);

    return addEntryPoint(translationUnitIndex, name, Profile(Stage(stage)), typeNames);
}

SlangResult EndToEndCompileRequest::setGlobalGenericArgs(int genericArgCount, char const** genericArgs)
{
    auto& argStrings = m_globalSpecializationArgStrings;
    argStrings.clear();
    for (int i = 0; i < genericArgCount; i++)
        argStrings.add(genericArgs[i]);

    return SLANG_OK;
}

SlangResult EndToEndCompileRequest::setTypeNameForGlobalExistentialTypeParam(int slotIndex, char const* typeName)
{
    if (slotIndex < 0)   return SLANG_FAIL;
    if (!typeName)       return SLANG_FAIL;

    auto& typeArgStrings = m_globalSpecializationArgStrings;
    if (Index(slotIndex) >= typeArgStrings.getCount())
        typeArgStrings.setCount(slotIndex + 1);
    typeArgStrings[slotIndex] = String(typeName);
    return SLANG_OK;
}

SlangResult EndToEndCompileRequest::setTypeNameForEntryPointExistentialTypeParam(int entryPointIndex, int slotIndex, char const* typeName)
{
    if (entryPointIndex < 0) return SLANG_FAIL;
    if (slotIndex < 0)       return SLANG_FAIL;
    if (!typeName)           return SLANG_FAIL;

    if (Index(entryPointIndex) >=m_entryPoints.getCount())
        return SLANG_FAIL;

    auto& entryPointInfo = m_entryPoints[entryPointIndex];
    auto& typeArgStrings = entryPointInfo.specializationArgStrings;
    if (Index(slotIndex) >= typeArgStrings.getCount())
        typeArgStrings.setCount(slotIndex + 1);
    typeArgStrings[slotIndex] = String(typeName);
    return SLANG_OK;
}

SlangResult EndToEndCompileRequest::EndToEndCompileRequest::compile()
{
    SlangResult res = SLANG_FAIL;

#if !defined(SLANG_DEBUG_INTERNAL_ERROR)
    // By default we'd like to catch as many internal errors as possible,
    // and report them to the user nicely (rather than just crash their
    // application). Internally Slang currently uses exceptions for this.
    //
    // TODO: Consider using `setjmp()`-style escape so that we can work
    // with applications that disable exceptions.
    //
    // TODO: Consider supporting Windows "Structured Exception Handling"
    // so that we can also recover from a wider class of crashes.

    try
    {
        res = executeActions();
    }
    catch (const AbortCompilationException&)
    {
        // This situation indicates a fatal (but not necessarily internal) error
        // that forced compilation to terminate. There should already have been
        // a diagnostic produced, so we don't need to add one here.
    }
    catch (const Exception& e)
    {
        // The compiler failed due to an internal error that was detected.
        // We will print out information on the exception to help out the user
        // in either filing a bug, or locating what in their code created
        // a problem.
        getSink()->diagnose(SourceLoc(), Diagnostics::compilationAbortedDueToException, typeid(e).name(), e.Message);
    }
    catch (...)
    {
        // The compiler failed due to some exception that wasn't a sublass of
        // `Exception`, so something really fishy is going on. We want to
        // let the user know that we messed up, so they know to blame Slang
        // and not some other component in their system.
        getSink()->diagnose(SourceLoc(), Diagnostics::compilationAborted);
    }
    m_diagnosticOutput = getSink()->outputBuffer.ProduceString();

#else
    // When debugging, we probably don't want to filter out any errors, since
    // we are probably trying to root-cause and *fix* those errors.
    {
        res = req->executeActions();
    }
#endif

    // Repro dump handling
    {
        if (m_dumpRepro.getLength())
        {
            SlangResult saveRes = ReproUtil::saveState(this, m_dumpRepro);
            if (SLANG_FAILED(saveRes))
            {
                getSink()->diagnose(SourceLoc(), Diagnostics::unableToWriteReproFile, m_dumpRepro);
                return saveRes;
            }
        }
        else if (m_dumpReproOnError && SLANG_FAILED(res)) 
        {
            String reproFileName;
            SlangResult saveRes = SLANG_FAIL;

            RefPtr<Stream> stream;
            if (SLANG_SUCCEEDED(ReproUtil::findUniqueReproDumpStream(this, reproFileName, stream)))
            {
                saveRes = ReproUtil::saveState(this, stream);
            }

            if (SLANG_FAILED(saveRes))
            {
                getSink()->diagnose(SourceLoc(), Diagnostics::unableToWriteReproFile, reproFileName);
            }
        }
    }

    return res;
}

int EndToEndCompileRequest::getDependencyFileCount()
{
    auto frontEndReq = getFrontEndReq();
    auto program = frontEndReq->getGlobalAndEntryPointsComponentType();
    return (int)program->getFilePathDependencies().getCount();
}

char const* EndToEndCompileRequest::getDependencyFilePath(int index)
{
    auto frontEndReq = getFrontEndReq();
    auto program = frontEndReq->getGlobalAndEntryPointsComponentType();
    return program->getFilePathDependencies()[index].begin();
}

int EndToEndCompileRequest::getTranslationUnitCount()
{
    return (int)getFrontEndReq()->translationUnits.getCount();
}

void const* EndToEndCompileRequest::getEntryPointCode(int entryPointIndex, size_t* outSize)
{
    // Zero the size initially, in case need to return nullptr for error.
    if (outSize)
    {
        *outSize = 0;
    }

    auto linkage = getLinkage();
    auto program = getSpecializedGlobalAndEntryPointsComponentType();

    // TODO: We should really accept a target index in this API
    Index targetIndex = 0;
    auto targetCount = linkage->targets.getCount();
    if (targetIndex >= targetCount)
        return nullptr;
    auto targetReq = linkage->targets[targetIndex];


    if (entryPointIndex < 0) return nullptr;
    if (Index(entryPointIndex) >= program->getEntryPointCount()) return nullptr;
    auto entryPoint = program->getEntryPoint(entryPointIndex);

    auto targetProgram = program->getTargetProgram(targetReq);
    if (!targetProgram)
        return nullptr;
    CompileResult& result = targetProgram->getExistingEntryPointResult(entryPointIndex);

    ComPtr<ISlangBlob> blob;
    SLANG_RETURN_NULL_ON_FAIL(result.getBlob(blob));

    if (outSize)
    {
        *outSize = blob->getBufferSize();
    }

    return (void*)blob->getBufferPointer();
}

static SlangResult _getEntryPointResult(
    EndToEndCompileRequest* req,
    int                     entryPointIndex,
    int                     targetIndex,
    Slang::CompileResult**  outCompileResult)
{
    auto linkage = req->getLinkage();
    auto program = req->getSpecializedGlobalAndEntryPointsComponentType();

    Index targetCount = linkage->targets.getCount();
    if ((targetIndex < 0) || (targetIndex >= targetCount))
    {
        return SLANG_E_INVALID_ARG;
    }
    auto targetReq = linkage->targets[targetIndex];

    Index entryPointCount = req->m_entryPoints.getCount();
    if ((entryPointIndex < 0) || (entryPointIndex >= entryPointCount))
    {
        return SLANG_E_INVALID_ARG;
    }
    auto entryPointReq = program->getEntryPoint(entryPointIndex);


    auto targetProgram = program->getTargetProgram(targetReq);
    if (!targetProgram)
        return SLANG_FAIL;
    *outCompileResult = &targetProgram->getExistingEntryPointResult(entryPointIndex);
    return SLANG_OK;
}

static SlangResult _getWholeProgramResult(
    EndToEndCompileRequest* req,
    int targetIndex,
    Slang::CompileResult** outCompileResult)
{
    auto linkage = req->getLinkage();
    auto program = req->getSpecializedGlobalAndEntryPointsComponentType();

    Index targetCount = linkage->targets.getCount();
    if ((targetIndex < 0) || (targetIndex >= targetCount))
    {
        return SLANG_E_INVALID_ARG;
    }
    auto targetReq = linkage->targets[targetIndex];

    auto targetProgram = program->getTargetProgram(targetReq);
    if (!targetProgram)
        return SLANG_FAIL;
    *outCompileResult = &targetProgram->getExistingWholeProgramResult();
    return SLANG_OK;
}

SlangResult EndToEndCompileRequest::getEntryPointCodeBlob(int entryPointIndex, int targetIndex, ISlangBlob** outBlob)
{
    if (!outBlob) return SLANG_E_INVALID_ARG;

    CompileResult* compileResult = nullptr;
    SLANG_RETURN_ON_FAIL(_getEntryPointResult(this, entryPointIndex, targetIndex, &compileResult));

    ComPtr<ISlangBlob> blob;
    SLANG_RETURN_ON_FAIL(compileResult->getBlob(blob));
    *outBlob = blob.detach();
    return SLANG_OK;
}

SlangResult EndToEndCompileRequest::getEntryPointHostCallable(int entryPointIndex, int targetIndex, ISlangSharedLibrary** outSharedLibrary)
{
    if (!outSharedLibrary) return SLANG_E_INVALID_ARG;

    CompileResult* compileResult = nullptr;
    SLANG_RETURN_ON_FAIL(_getEntryPointResult(this, entryPointIndex, targetIndex, &compileResult));

    ComPtr<ISlangSharedLibrary> sharedLibrary;
    SLANG_RETURN_ON_FAIL(compileResult->getSharedLibrary(sharedLibrary));
    *outSharedLibrary = sharedLibrary.detach();
    return SLANG_OK;
}

SlangResult EndToEndCompileRequest::getTargetCodeBlob(int targetIndex, ISlangBlob** outBlob)
{
    if (!outBlob)
        return SLANG_E_INVALID_ARG;

    CompileResult* compileResult = nullptr;
    SLANG_RETURN_ON_FAIL(_getWholeProgramResult(this, targetIndex, &compileResult));

    ComPtr<ISlangBlob> blob;
    SLANG_RETURN_ON_FAIL(compileResult->getBlob(blob));
    *outBlob = blob.detach();
    return SLANG_OK;
}

SlangResult EndToEndCompileRequest::getTargetHostCallable(int targetIndex,ISlangSharedLibrary** outSharedLibrary)
{
    if (!outSharedLibrary)
        return SLANG_E_INVALID_ARG;

    CompileResult* compileResult = nullptr;
    SLANG_RETURN_ON_FAIL(_getWholeProgramResult(this, targetIndex, &compileResult));

    ComPtr<ISlangSharedLibrary> sharedLibrary;
    SLANG_RETURN_ON_FAIL(compileResult->getSharedLibrary(sharedLibrary));
    *outSharedLibrary = sharedLibrary.detach();
    return SLANG_OK;
}

char const* EndToEndCompileRequest::getEntryPointSource(int entryPointIndex)
{
    return (char const*)getEntryPointCode(entryPointIndex, nullptr);
}

void const* EndToEndCompileRequest::getCompileRequestCode(size_t* outSize)
{
    if (m_containerBlob)
    {
        *outSize = m_containerBlob->getBufferSize();
        return m_containerBlob->getBufferPointer();
    }

    // Container blob does not have any contents
    *outSize = 0;
    return nullptr;
}

SlangResult EndToEndCompileRequest::getContainerCode(ISlangBlob** outBlob)
{
    ISlangBlob* containerBlob = m_containerBlob;
    if (containerBlob)
    {
        containerBlob->addRef();
        *outBlob = containerBlob;
        return SLANG_OK;
    }

    return SLANG_FAIL;
}

SlangResult EndToEndCompileRequest::loadRepro(ISlangFileSystem* fileSystem, const void* data, size_t size)
{
    List<uint8_t> buffer;
    SLANG_RETURN_ON_FAIL(ReproUtil::loadState((const uint8_t*)data, size, getSink(), buffer));

    MemoryOffsetBase base;
    base.set(buffer.getBuffer(), buffer.getCount());

    ReproUtil::RequestState* requestState = ReproUtil::getRequest(buffer);

    SLANG_RETURN_ON_FAIL(ReproUtil::load(base, requestState, fileSystem, this));
    return SLANG_OK;
}

SlangResult EndToEndCompileRequest::saveRepro(ISlangBlob** outBlob)
{
    OwnedMemoryStream stream(FileAccess::Write);

    SLANG_RETURN_ON_FAIL(ReproUtil::saveState(this, &stream));

    RefPtr<ListBlob> listBlob(new ListBlob);

    // Put the content of the stream in the blob
    stream.swapContents(listBlob->m_data);

    *outBlob = listBlob.detach();
    return SLANG_OK;
}

SlangResult EndToEndCompileRequest::enableReproCapture()
{
    getLinkage()->setRequireCacheFileSystem(true);
    return SLANG_OK;
}

SlangResult EndToEndCompileRequest::processCommandLineArguments(char const* const* args, int argCount)
{
    return parseOptions(this, argCount, args);
}

SlangReflection* EndToEndCompileRequest::getReflection()
{
    auto linkage = getLinkage();
    auto program = getSpecializedGlobalAndEntryPointsComponentType();

    // Note(tfoley): The API signature doesn't let the client
    // specify which target they want to access reflection
    // information for, so for now we default to the first one.
    //
    // TODO: Add a new `spGetReflectionForTarget(req, targetIndex)`
    // so that we can do this better, and make it clear that
    // `spGetReflection()` is shorthand for `targetIndex == 0`.
    //
    Slang::Index targetIndex = 0;
    auto targetCount = linkage->targets.getCount();
    if (targetIndex >= targetCount)
        return nullptr;

    auto targetReq = linkage->targets[targetIndex];
    auto targetProgram = program->getTargetProgram(targetReq);


    DiagnosticSink sink(linkage->getSourceManager(), Lexer::sourceLocationLexer);
    auto programLayout = targetProgram->getOrCreateLayout(&sink);

    return (SlangReflection*)programLayout;
}

SlangResult EndToEndCompileRequest::getProgram(slang::IComponentType** outProgram)
{
    auto program = getSpecializedGlobalComponentType();
    *outProgram = Slang::ComPtr<slang::IComponentType>(program).detach();
    return SLANG_OK;
}

SlangResult EndToEndCompileRequest::getProgramWithEntryPoints(slang::IComponentType** outProgram)
{
    auto program = getSpecializedGlobalAndEntryPointsComponentType();
    *outProgram = Slang::ComPtr<slang::IComponentType>(program).detach();
    return SLANG_OK;
}

SlangResult EndToEndCompileRequest::getModule(SlangInt translationUnitIndex, slang::IModule** outModule)
{
    auto module = getFrontEndReq()->getTranslationUnit(translationUnitIndex)->getModule();

    *outModule = Slang::ComPtr<slang::IModule>(module).detach();
    return SLANG_OK;
}

SlangResult EndToEndCompileRequest::getSession(slang::ISession** outSession)
{
    auto session = getLinkage();
    *outSession = Slang::ComPtr<slang::ISession>(session).detach();
    return SLANG_OK;
}

SlangResult EndToEndCompileRequest::getEntryPoint(SlangInt entryPointIndex, slang::IComponentType** outEntryPoint)
{
    auto entryPoint = getSpecializedEntryPointComponentType(entryPointIndex);
    *outEntryPoint = Slang::ComPtr<slang::IComponentType>(entryPoint).detach();
    return SLANG_OK;
}

} // namespace Slang