// slang-options.cpp

// Implementation of options parsing for `slangc` command line,
// and also for API interface that takes command-line argument strings.

#include "slang-options.h"

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

#include "slang-compiler.h"
#include "slang-profile.h"

#include "../compiler-core/slang-artifact-desc-util.h"

#include "../compiler-core/slang-artifact-impl.h"
#include "../compiler-core/slang-artifact-representation-impl.h"

#include "../compiler-core/slang-name-convention-util.h"

#include "slang-repro.h"
#include "slang-serialize-ir.h"
#include "slang-hlsl-to-vulkan-layout-options.h"

#include "../core/slang-castable.h"
#include "../core/slang-file-system.h"
#include "../core/slang-type-text-util.h"
#include "../core/slang-hex-dump-util.h"

#include "../compiler-core/slang-command-line-args.h"
#include "../compiler-core/slang-artifact-desc-util.h"
#include "../compiler-core/slang-core-diagnostics.h"
#include "../compiler-core/slang-source-embed-util.h"

#include "../core/slang-string-slice-pool.h"
#include "../core/slang-char-util.h"

#include "../core/slang-name-value.h"

#include "../core/slang-command-options-writer.h"

#include <assert.h>

namespace Slang {

namespace { // anonymous

// All of the options are given an unique enum
enum class OptionKind
{
    // General

    MacroDefine,
    DepFile,
    EntryPointName,
    Help,
    HelpStyle,
    Include,
    Language,
    MatrixLayoutColumn,
    MatrixLayoutRow,
    ModuleName,
    Output,
    Profile,
    Stage,
    Target,
    Version,
    WarningsAsErrors,
    DisableWarnings,
    EnableWarning,
    DisableWarning,
    DumpWarningDiagnostics,
    InputFilesRemain,
    EmitIr,
    ReportDownstreamTime,
    ReportPerfBenchmark,

    SourceEmbedStyle,
    SourceEmbedName,
    SourceEmbedLanguage,

    // Target

    Capability,
    DefaultImageFormatUnknown,
    DisableDynamicDispatch,
    DisableSpecialization,
    FloatingPointMode,
    DebugInformation,
    LineDirectiveMode,
    Optimization,
    Obfuscate,

    VulkanBindShift,
    VulkanBindGlobals,
    VulkanInvertY,
    VulkanUseEntryPointName,
    VulkanUseGLLayout,
    VulkanEmitReflection,

    GLSLForceScalarLayout,
    EnableEffectAnnotations,

    EmitSpirvViaGLSL,
    EmitSpirvDirectly,
    SPIRVCoreGrammarJSON,
    
    // Downstream

    CompilerPath,
    DefaultDownstreamCompiler,
    DownstreamArgs,
    PassThrough,

    // Repro

    DumpRepro,
    DumpReproOnError,
    ExtractRepro,
    LoadRepro,
    LoadReproDirectory,
    ReproFallbackDirectory,

    // Debugging

    DumpAst,
    DumpIntermediatePrefix,
    DumpIntermediates,
    DumpIr,
    DumpIrIds,
    PreprocessorOutput,
    NoCodeGen,
    OutputIncludes,
    ReproFileSystem,
    SerialIr,
    SkipCodeGen,
    ValidateIr,
    VerbosePaths,
    VerifyDebugSerialIr,

    // Experimental

    FileSystem,
    Heterogeneous,
    NoMangle,
    AllowGLSL,

    // Internal

    ArchiveType,
    CompileStdLib,
    Doc,
    IrCompression,
    LoadStdLib,
    ReferenceModule,
    SaveStdLib,
    SaveStdLibBinSource,
    TrackLiveness,

    // Deprecated
    ParameterBlocksUseRegisterSpaces,

    CountOf,
};

struct Option
{
    OptionKind optionKind;
    const char* name;
    const char* usage = nullptr;
    const char* description = nullptr;
};

enum class ValueCategory
{
    Compiler,
    Target,
    Language,
    FloatingPointMode,
    ArchiveType,
    Stage,
    LineDirectiveMode,
    DebugInfoFormat,
    HelpStyle,
    OptimizationLevel,
    DebugLevel, 
    FileSystemType,
    VulkanShift,
    SourceEmbedStyle,

    CountOf,
};

template <typename T>
struct GetValueCategory;

#define SLANG_GET_VALUE_CATEGORY(cat, type) template <> struct GetValueCategory<type> { enum { Value = Index(ValueCategory::cat) }; }; 

SLANG_GET_VALUE_CATEGORY(Compiler, SlangPassThrough)
SLANG_GET_VALUE_CATEGORY(ArchiveType, SlangArchiveType)
SLANG_GET_VALUE_CATEGORY(LineDirectiveMode, SlangLineDirectiveMode)
SLANG_GET_VALUE_CATEGORY(FloatingPointMode, FloatingPointMode)
SLANG_GET_VALUE_CATEGORY(FileSystemType, TypeTextUtil::FileSystemType)
SLANG_GET_VALUE_CATEGORY(HelpStyle, CommandOptionsWriter::Style)
SLANG_GET_VALUE_CATEGORY(OptimizationLevel, SlangOptimizationLevel)
SLANG_GET_VALUE_CATEGORY(VulkanShift, HLSLToVulkanLayoutOptions::Kind)
SLANG_GET_VALUE_CATEGORY(SourceEmbedStyle, SourceEmbedUtil::Style)
SLANG_GET_VALUE_CATEGORY(Language, SourceLanguage)

} // anonymous

static void _addOptions(const ConstArrayView<Option>& options, CommandOptions& cmdOptions)
{
    for (auto& opt : options)
    {
        cmdOptions.add(opt.name, opt.usage, opt.description, CommandOptions::UserValue(opt.optionKind));
    }
}

void initCommandOptions(CommandOptions& options)
{
    typedef CommandOptions::Flag::Enum Flag;
    typedef CommandOptions::CategoryKind CategoryKind;
    typedef CommandOptions::UserValue UserValue;

    // Add all the option categories

    options.addCategory(CategoryKind::Option, "General", "General options");
    options.addCategory(CategoryKind::Option, "Target", "Target code generation options");
    options.addCategory(CategoryKind::Option, "Downstream", "Downstream compiler options");
    options.addCategory(CategoryKind::Option, "Debugging", "Compiler debugging/instrumentation options");
    options.addCategory(CategoryKind::Option, "Repro", "Slang repro system related");
    options.addCategory(CategoryKind::Option, "Experimental", "Experimental options (use at your own risk)");
    options.addCategory(CategoryKind::Option, "Internal", "Internal-use options (use at your own risk)");
    options.addCategory(CategoryKind::Option, "Deprecated", "Deprecated options (allowed but ignored; may be removed in future)");

    // Do the easy ones
    {
        options.addCategory(CategoryKind::Value, "compiler", "Downstream Compilers (aka Pass through)", UserValue(ValueCategory::Compiler));
        options.addValues(TypeTextUtil::getCompilerInfos());
    
        options.addCategory(CategoryKind::Value, "language", "Language", UserValue(ValueCategory::Language));
        options.addValues(TypeTextUtil::getLanguageInfos());

        options.addCategory(CategoryKind::Value, "archive-type", "Archive Type", UserValue(ValueCategory::ArchiveType));
        options.addValues(TypeTextUtil::getArchiveTypeInfos());

        options.addCategory(CategoryKind::Value, "line-directive-mode", "Line Directive Mode", UserValue(ValueCategory::LineDirectiveMode));
        options.addValues(TypeTextUtil::getLineDirectiveInfos());

        options.addCategory(CategoryKind::Value, "debug-info-format", "Debug Info Format", UserValue(ValueCategory::DebugInfoFormat));
        options.addValues(TypeTextUtil::getDebugInfoFormatInfos());

        options.addCategory(CategoryKind::Value, "fp-mode", "Floating Point Mode", UserValue(ValueCategory::FloatingPointMode));
        options.addValues(TypeTextUtil::getFloatingPointModeInfos());

        options.addCategory(CategoryKind::Value, "help-style", "Help Style", UserValue(ValueCategory::HelpStyle));
        options.addValues(CommandOptionsWriter::getStyleInfos());

        options.addCategory(CategoryKind::Value, "optimization-level", "Optimization Level", UserValue(ValueCategory::OptimizationLevel));
        options.addValues(TypeTextUtil::getOptimizationLevelInfos());

        options.addCategory(CategoryKind::Value, "debug-level", "Debug Level", UserValue(ValueCategory::DebugLevel));
        options.addValues(TypeTextUtil::getDebugLevelInfos());

        options.addCategory(CategoryKind::Value, "file-system-type", "File System Type", UserValue(ValueCategory::FileSystemType));
        options.addValues(TypeTextUtil::getFileSystemTypeInfos());

        options.addCategory(CategoryKind::Value, "source-embed-style", "Source Embed Style", UserValue(ValueCategory::SourceEmbedStyle));
        options.addValues(SourceEmbedUtil::getStyleInfos());
    }

    /* !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! target !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! */

    {
        options.addCategory(CategoryKind::Value, "target", "Target", UserValue(ValueCategory::Target));
        for (auto opt : TypeTextUtil::getCompileTargetInfos())
        {
            options.addValue(opt.names, opt.description, UserValue(opt.target));
        }
    }

    /* !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! stage !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! */

    {
        options.addCategory(CategoryKind::Value, "stage", "Stage", UserValue(ValueCategory::Stage));
        List<NameValue> opts;
        for (auto& info: getStageInfos())
        {
            opts.add({ValueInt(info.stage), info.name });
        }
        options.addValuesWithAliases(opts.getArrayView());
    }

    /* !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! vulkan-shift !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! */

    {
        options.addCategory(CategoryKind::Value, "vulkan-shift", "Vulkan Shift", UserValue(ValueCategory::VulkanShift));
        options.addValues(HLSLToVulkanLayoutOptions::getKindInfos());
    }
    
    /* !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! capabilities !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! */

    {
        options.addCategory(CategoryKind::Value, "capability", 
            "A capability describes an optional feature that a target may or "
            "may not support. When a -capability is specified, the compiler "
            "may assume that the target supports that capability, and generate "
            "code accordingly.");

        List<UnownedStringSlice> names;
        getCapabilityNames(names);

        // We'll just add to keep the list more simple...
        options.addValue("spirv_1_{ 0,1,2,3,4,5 }", "minimum supported SPIR - V version");

        for (auto name : names)
        {
            if (name.startsWith("__") || 
                name.startsWith("spirv_1_") ||
                name.startsWith("_"))
            {
                continue;
            }
            else if (name.startsWith("GL_") || name.startsWith("SPV_") || name.startsWith("GLSL_"))
            {
                // We'll assume it is an extension..
                StringBuilder buf;
                buf << "enables the " << name << " extension";
                options.addValue(name, buf.getUnownedSlice());
            }
            else
            {
                options.addValue(name);
            }
        }
    }

    /* !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! extension !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! */

    {
        options.addCategory(CategoryKind::Value, "file-extension",
            "A <language>, <format>, and/or <stage> may be inferred from the "
            "extension of an input or -o path");

        // TODO(JS): It's concevable that these are enumerated via some other system
        // rather than just being listed here

        const CommandOptions::ValuePair pairs[] = 
        {
            {"hlsl,fx", "hlsl"},
            {"dxbc", nullptr},
            {"dxbc-asm", "dxbc-assembly"},
            {"dxil", nullptr},
            {"dxil-asm", "dxil-assembly"},
            {"glsl", nullptr},
            {"vert", "glsl (vertex)"},
            {"frag", "glsl (fragment)"},
            {"geom", "glsl (geoemtry)"},
            {"tesc", "glsl (hull)"},
            {"tese", "glsl (domain)"},
            {"comp", "glsl (compute)"},
            {"slang", nullptr},
            {"spv", "SPIR-V"},
            {"spv-asm", "SPIR-V assembly"},
            {"c", nullptr},
            {"cpp,c++,cxx", "C++"},
            {"exe", "executable"},
            {"dll,so", "sharedlibrary/dll"},
            {"cu", "CUDA"},
            {"ptx", "PTX"},
            {"obj,o", "object-code"},
            {"zip", "container"},
            {"slang-module,slang-library", "Slang Module/Library"},
            {"dir", "Container as a directory"},
        };
        options.addValues(pairs, SLANG_COUNT_OF(pairs));
    }

    /* !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! General !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! */

    options.setCategory("General");

    const Option generalOpts[] = 
    {
        { OptionKind::MacroDefine,  "-D?...",   "-D<name>[=<value>], -D <name>[=<value>]",
        "Insert a preprocessor macro.\n"
        "The space between - D and <name> is optional. If no <value> is specified, Slang will define the macro with an empty value." },
        { OptionKind::DepFile,      "-depfile", "-depfile <path>", "Save the source file dependency list in a file." },
        { OptionKind::EntryPointName, "-entry", "-entry <name>",
        "Specify the name of an entry-point function.\n"
        "When compiling from a single file, this defaults to main if you specify a stage using -stage.\n"
        "Multiple -entry options may be used in a single invocation. "
        "When they do, the file associated with the entry point will be the first one found when searching to the left in the command line.\n"
        "If no -entry options are given, compiler will use [shader(...)] "
        "attributes to detect entry points."},
        { OptionKind::EmitIr,       "-emit-ir", nullptr, "Emit IR typically as a '.slang-module' when outputting to a container." },
        { OptionKind::Help,         "-h,-help,--help", "-h or -h <help-category>", "Print this message, or help in specified category." },
        { OptionKind::HelpStyle,    "-help-style", "-help-style <help-style>", "Help formatting style" },
        { OptionKind::Include,      "-I?...", "-I<path>, -I <path>",
        "Add a path to be used in resolving '#include' "
        "and 'import' operations."},
        { OptionKind::Language,     "-lang", "-lang <language>", "Set the language for the following input files."},
        { OptionKind::MatrixLayoutColumn, "-matrix-layout-column-major", nullptr, "Set the default matrix layout to column-major."},
        { OptionKind::MatrixLayoutRow,"-matrix-layout-row-major", nullptr, "Set the default matrix layout to row-major."},
        { OptionKind::ModuleName,     "-module-name", "-module-name <name>", 
        "Set the module name to use when compiling multiple .slang source files into a single module."},
        { OptionKind::Output, "-o", "-o <path>", 
        "Specify a path where generated output should be written.\n"
        "If no -target or -stage is specified, one may be inferred "
        "from file extension (see <file-extension>). "
        "If multiple -target options and a single -entry are present, each -o "
        "associates with the first -target to its left. "
        "Otherwise, if multiple -entry options are present, each -o associates "
        "with the first -entry to its left, and with the -target that matches "
        "the one inferred from <path>."},
        { OptionKind::Profile, "-profile", "-profile <profile>[+<capability>...]",
        "Specify the shader profile for code generation.\n"
        "Accepted profiles are:\n"
        "* sm_{4_0,4_1,5_0,5_1,6_0,6_1,6_2,6_3,6_4,6_5,6_6}\n"
        "* glsl_{110,120,130,140,150,330,400,410,420,430,440,450,460}\n"
        "Additional profiles that include -stage information:\n"
        "* {vs,hs,ds,gs,ps}_<version>\n"
        "See -capability for information on <capability>\n"
        "When multiple -target options are present, each -profile associates "
        "with the first -target to its left."},
        { OptionKind::Stage, "-stage", "-stage <stage>",
        "Specify the stage of an entry-point function.\n"
        "When multiple -entry options are present, each -stage associated with "
        "the first -entry to its left.\n"
        "May be omitted if entry-point function has a [shader(...)] attribute; "
        "otherwise required for each -entry option."},
        { OptionKind::Target, "-target", "-target <target>", "Specifies the format in which code should be generated."},
        { OptionKind::Version, "-v,-version", nullptr, 
            "Display the build version. This is the contents of git describe --tags.\n"
            "It is typically only set from automated builds(such as distros available on github).A user build will by default be 'unknown'."},
        { OptionKind::WarningsAsErrors, "-warnings-as-errors", "-warnings-as-errors all or -warnings-as-errors <id>[,<id>...]", 
        "all - Treat all warnings as errors.\n"
        "<id>[,<id>...]: Treat specific warning ids as errors.\n"},
        { OptionKind::DisableWarnings, "-warnings-disable", "-warnings-disable <id>[,<id>...]", "Disable specific warning ids."},
        { OptionKind::EnableWarning, "-W...", "-W<id>", "Enable a warning with the specified id."},
        { OptionKind::DisableWarning, "-Wno-...", "-Wno-<id>", "Disable warning with <id>"},
        { OptionKind::DumpWarningDiagnostics, "-dump-warning-diagnostics", nullptr, "Dump to output list of warning diagnostic numeric and name ids." },
        { OptionKind::InputFilesRemain, "--", nullptr, "Treat the rest of the command line as input files."},
        { OptionKind::ReportDownstreamTime, "-report-downstream-time", nullptr, "Reports the time spent in the downstream compiler." },
        { OptionKind::ReportPerfBenchmark, "-report-perf-benchmark", nullptr, "Reports compiler performance benchmark results." },
        { OptionKind::SourceEmbedStyle, "-source-embed-style", "-source-embed-style <source-embed-style>",
        "If source embedding is enabled, defines the style used. When enabled (with any style other than `none`), "
        "will write compile results into embeddable source for the target language. "
        "If no output file is specified, the output is written to stdout. If an output file is specified "
        "it is written either to that file directly (if it is appropriate for the target language), "
        "or it will be output to the filename with an appropriate extension.\n\n"
        "Note for C/C++ with u16/u32/u64 types it is necessary to have \"#include <stdint.h>\" before the generated file.\n" },
        { OptionKind::SourceEmbedName, "-source-embed-name", "-source-embed-name <name>",
        "The name used as the basis for variables output for source embedding."},
        { OptionKind::SourceEmbedLanguage, "-source-embed-language", "-source-embed-language <language>",
        "The language to be used for source embedding. Defaults to C/C++. Currently only C/C++ are supported"},
    };

    _addOptions(makeConstArrayView(generalOpts), options);

    /* !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Target !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! */

    options.setCategory("Target");

    StringBuilder vkShiftNames;
    {
        for (auto nameSlice : NameValueUtil::getNames(NameValueUtil::NameKind::All, HLSLToVulkanLayoutOptions::getKindInfos()))
        {
            // -fvk-{b|s|t|u}-shift
            vkShiftNames << "-fvk-" << nameSlice << "-shift,";
        }
        // remove last ,
        vkShiftNames.reduceLength(vkShiftNames.getLength() - 1);
    }

    const Option targetOpts[] = 
    {
        { OptionKind::Capability, "-capability", "-capability <capability>[+<capability>...]",
        "Add optional capabilities to a code generation target. See Capabilities below."},
        { OptionKind::DefaultImageFormatUnknown, "-default-image-format-unknown", nullptr,
        "Set the format of R/W images with unspecified format to 'unknown'. Otherwise try to guess the format."},
        { OptionKind::DisableDynamicDispatch, "-disable-dynamic-dispatch", nullptr, "Disables generating dynamic dispatch code." },
        { OptionKind::DisableSpecialization, "-disable-specialization", nullptr, "Disables generics and specialization pass." },
        { OptionKind::FloatingPointMode, "-fp-mode,-floating-point-mode", "-fp-mode <fp-mode>, -floating-point-mode <fp-mode>", 
        "Control floating point optimizations"},
        { OptionKind::DebugInformation, "-g...", "-g, -g<debug-info-format>, -g<debug-level>", 
        "Include debug information in the generated code, where possible.\n"
        "<debug-level> is the amount of information, 0..3, unspecified means 2\n" 
        "<debug-info-format> specifies a debugging info format\n"
        "It is valid to have multiple -g options, such as a <debug-level> and a <debug-info-format>" },
        { OptionKind::LineDirectiveMode, "-line-directive-mode", "-line-directive-mode <line-directive-mode>", 
        "Sets how the `#line` directives should be produced. Available options are:\n"
        "If not specified, default behavior is to use C-style `#line` directives "
        "for HLSL and C/C++ output, and traditional GLSL-style `#line` directives "
        "for GLSL output." },
        { OptionKind::Optimization, "-O...", "-O<optimization-level>", "Set the optimization level."},
        { OptionKind::Obfuscate, "-obfuscate", nullptr, "Remove all source file information from outputs." },
        { OptionKind::GLSLForceScalarLayout,
         "-force-glsl-scalar-layout", nullptr,
         "Force using scalar block layout for uniform and shader storage buffers in GLSL output."},
        { OptionKind::VulkanBindShift, vkShiftNames.getBuffer(), "-fvk-<vulkan-shift>-shift <N> <space>", 
        "For example '-fvk-b-shift <N> <space>' shifts by N the inferred binding numbers for all resources in 'b' registers of space <space>. "
        "For a resource attached with :register(bX, <space>) but not [vk::binding(...)], "
        "sets its Vulkan descriptor set to <space> and binding number to X + N. If you need to shift the "
        "inferred binding numbers for more than one space, provide more than one such option. "
        "If more than one such option is provided for the same space, the last one takes effect. "
        "If you need to shift the inferred binding numbers for all sets, use 'all' as <space>. " 
        "\n"
        "* [DXC description](https://github.com/Microsoft/DirectXShaderCompiler/blob/main/docs/SPIR-V.rst#implicit-binding-number-assignment)\n" 
        "* [GLSL wiki](https://github.com/KhronosGroup/glslang/wiki/HLSL-FAQ#auto-mapped-binding-numbers)\n" },
        { OptionKind::VulkanBindGlobals, "-fvk-bind-globals", "-fvk-bind-globals <N> <descriptor-set>",
        "Places the $Globals cbuffer at descriptor set <descriptor-set> and binding <N>."},
        { OptionKind::VulkanInvertY, "-fvk-invert-y", nullptr, "Negates (additively inverts) SV_Position.y before writing to stage output."},
        { OptionKind::VulkanUseEntryPointName, "-fvk-use-entrypoint-name", nullptr, "Uses the entrypoint name from the source instead of 'main' in the spirv output."},
        { OptionKind::VulkanUseGLLayout, "-fvk-use-gl-layout", nullptr, "Use std430 layout instead of D3D buffer layout for raw buffer load/stores."},
        { OptionKind::VulkanEmitReflection, "-fspv-reflect", nullptr, "Include reflection decorations in the resulting SPIRV for shader parameters."},
        { OptionKind::EnableEffectAnnotations,
         "-enable-effect-annotations", nullptr, 
         "Enables support for legacy effect annotation syntax."},
#if defined(SLANG_CONFIG_DEFAULT_SPIRV_DIRECT)
        { OptionKind::EmitSpirvViaGLSL, "-emit-spirv-via-glsl", nullptr,
        "Generate SPIR-V output by compiling generated GLSL with glslang" },
        { OptionKind::EmitSpirvDirectly, "-emit-spirv-directly", nullptr,
        "Generate SPIR-V output direclty (default)" },
#else
        { OptionKind::EmitSpirvViaGLSL, "-emit-spirv-via-glsl", nullptr,
        "Generate SPIR-V output by compiling generated GLSL with glslang (default)" },
        { OptionKind::EmitSpirvDirectly, "-emit-spirv-directly", nullptr,
        "Generate SPIR-V output direclty rather than by compiling generated GLSL with glslang" },
        { OptionKind::SPIRVCoreGrammarJSON, "-spirv-core-grammar", nullptr,
        "A path to a specific spirv.core.grammar.json to use when generating SPIR-V output" },
#endif
    };

    _addOptions(makeConstArrayView(targetOpts), options);

    /* !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Downstream !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! */

    options.setCategory("Downstream");

    {
        auto namesList = NameValueUtil::getNames(NameValueUtil::NameKind::First, TypeTextUtil::getCompilerInfos());
        StringBuilder names;
        for (auto name : namesList)
        {
            names << "-" << name << "-path,";
        }
        // remove last ,
        names.reduceLength(names.getLength() - 1);

        options.add(names.getBuffer(), "-<compiler>-path <path>", 
            "Specify path to a downstream <compiler> "
            "executable or library.\n", 
            UserValue(OptionKind::CompilerPath));
    }

    const Option downstreamOpts[] = 
    {
        { OptionKind::DefaultDownstreamCompiler, "-default-downstream-compiler", "-default-downstream-compiler <language> <compiler>",
        "Set a default compiler for the given language. See -lang for the list of languages." },
        { OptionKind::DownstreamArgs, "-X...", "-X<compiler> <option> -X<compiler>... <options> -X.", 
        "Pass arguments to downstream <compiler>. Just -X<compiler> passes just the next argument "
        "to the downstream compiler. -X<compiler>... options -X. will pass *all* of the options "
        "inbetween the opening -X and -X. to the downstream compiler."},
        { OptionKind::PassThrough, "-pass-through", "-pass-through <compiler>", 
        "Pass the input through mostly unmodified to the "
        "existing compiler <compiler>.\n" 
        "These are intended for debugging/testing purposes, when you want to be able to see what these existing compilers do with the \"same\" input and options"},
    };

    _addOptions(makeConstArrayView(downstreamOpts), options);

    /* !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Repro !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! */

    options.setCategory("Repro");

    const Option reproOpts[] =
    {
        { OptionKind::DumpReproOnError, "-dump-repro-on-error", nullptr, "Dump `.slang-repro` file on any compilation error." },
        { OptionKind::ExtractRepro, "-extract-repro", "-extract-repro <name>", "Extract the repro files into a folder." },
        { OptionKind::LoadReproDirectory, "-load-repro-directory", "-load-repro-directory <path>", "Use repro along specified path" },
        { OptionKind::LoadRepro, "-load-repro", "-load-repro <name>", "Load repro"},
        { OptionKind::ReproFileSystem, "-repro-file-system", "-repro-file-system <name>", "Use a repro as a file system" },
        { OptionKind::DumpRepro, "-dump-repro", nullptr, "Dump a `.slang-repro` file that can be used to reproduce "
        "a compilation on another machine.\n"},
        { OptionKind::ReproFallbackDirectory, "-repro-fallback-directory <path>", 
        "Specify a directory to use if a file isn't found in a repro. Should be specified *before* any repro usage such as `load-repro`. \n"
        "There are two *special* directories: \n\n"
        " * 'none:' indicates no fallback, so if the file isn't found in the repro compliation will fail\n" 
        " * 'default:' is the default (which is the OS file system)"}
    };

    _addOptions(makeConstArrayView(reproOpts), options);

    /* !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Debugging !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! */

    options.setCategory("Debugging");

    const Option debuggingOpts[] = 
    {
        { OptionKind::DumpAst, "-dump-ast", nullptr, "Dump the AST to a .slang-ast file next to the input." },
        { OptionKind::DumpIntermediatePrefix, "-dump-intermediate-prefix", "-dump-intermediate-prefix <prefix>", 
        "File name prefix for -dump-intermediates outputs, default is 'slang-dump-'"},
        { OptionKind::DumpIntermediates, "-dump-intermediates", nullptr, "Dump intermediate outputs for debugging." },
        { OptionKind::DumpIr, "-dump-ir", nullptr, "Dump the IR for debugging." },
        { OptionKind::DumpIrIds, "-dump-ir-ids", nullptr, "Dump the IDs with -dump-ir (debug builds only)" },
        { OptionKind::PreprocessorOutput, "-E,-output-preprocessor", nullptr, "Output the preprocessing result and exit." },
        { OptionKind::NoCodeGen, "-no-codegen", nullptr, "Skip the code generation step, just check the code and generate layout." },
        { OptionKind::OutputIncludes, "-output-includes", nullptr, "Print the hierarchy of the processed source files." },
        { OptionKind::SerialIr, "-serial-ir", nullptr, "Serialize the IR between front-end and back-end." },
        { OptionKind::SkipCodeGen, "-skip-codegen", nullptr, "Skip the code generation phase." },
        { OptionKind::ValidateIr, "-validate-ir", nullptr, "Validate the IR between the phases." },
        { OptionKind::VerbosePaths, "-verbose-paths", nullptr, "When displaying diagnostic output aim to display more detailed path information. "
        "In practice this is typically the complete 'canonical' path to the source file used." },
        { OptionKind::VerifyDebugSerialIr, "-verify-debug-serial-ir", nullptr, "Verify IR in the front-end." }
    };
    _addOptions(makeConstArrayView(debuggingOpts), options);
    
    /* !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Experimental !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! */

    options.setCategory("Experimental");

    const Option experimentalOpts[] = 
    {
        { OptionKind::FileSystem, "-file-system", "-file-system <file-system-type>", 
        "Set the filesystem hook to use for a compile request."},
        { OptionKind::Heterogeneous, "-heterogeneous", nullptr, "Output heterogeneity-related code." },
        { OptionKind::NoMangle, "-no-mangle", nullptr, "Do as little mangling of names as possible." },
        { OptionKind::AllowGLSL, "-allow-glsl", nullptr, "Enable GLSL as an input language." },
    };
    _addOptions(makeConstArrayView(experimentalOpts), options);

    /* !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Internal !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! */

    options.setCategory("Internal");

    const Option internalOpts[] = 
    {
        { OptionKind::ArchiveType, "-archive-type", "-archive-type <archive-type>", "Set the archive type for -save-stdlib. Default is zip." },
        { OptionKind::CompileStdLib, "-compile-stdlib", nullptr, 
        "Compile the StdLib from embedded sources. "
        "Will return a failure if there is already a StdLib available."},
        { OptionKind::Doc, "-doc", nullptr, "Write documentation for -compile-stdlib" },
        { OptionKind::IrCompression,"-ir-compression", "-ir-compression <type>", 
        "Set compression for IR and AST outputs.\n"
        "Accepted compression types: none, lite"},
        { OptionKind::LoadStdLib, "-load-stdlib", "-load-stdlib <filename>", "Load the StdLib from file." },
        { OptionKind::ReferenceModule, "-r", "-r <name>", "reference module <name>" },
        { OptionKind::SaveStdLib, "-save-stdlib", "-save-stdlib <filename>", "Save the StdLib modules to an archive file." },
        { OptionKind::SaveStdLibBinSource, "-save-stdlib-bin-source","-save-stdlib-bin-source <filename>", "Same as -save-stdlib but output "
        "the data as a C array.\n"},
        { OptionKind::TrackLiveness, "-track-liveness", nullptr, "Enable liveness tracking. Places SLANG_LIVE_START, and SLANG_LIVE_END in output source to indicate value liveness." },
    };
    _addOptions(makeConstArrayView(internalOpts), options);

    /* !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Deprecated !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! */

    options.setCategory("Deprecated");

    const Option deprecatedOpts[] =
    {
        { OptionKind::ParameterBlocksUseRegisterSpaces, "-parameter-blocks-use-register-spaces", nullptr, "Parameter blocks will use register spaces" },
    };
    _addOptions(makeConstArrayView(deprecatedOpts), options);

    // We can now check that the whole range is available. If this fails it means there 
    // is an enum in the list that hasn't been setup as an option!
    SLANG_ASSERT(options.hasContiguousUserValueRange(CommandOptions::LookupKind::Option, UserValue(0), UserValue(OptionKind::CountOf)));
    SLANG_ASSERT(options.hasContiguousUserValueRange(CommandOptions::LookupKind::Category, UserValue(0), UserValue(ValueCategory::CountOf)));
}

SlangResult _addLibraryReference(EndToEndCompileRequest* req, IArtifact* artifact);

class ReproPathVisitor : public Slang::Path::Visitor
{
public:
    virtual void accept(Slang::Path::Type type, const Slang::UnownedStringSlice& filename) SLANG_OVERRIDE
    {
        if (type == Path::Type::File && Path::getPathExt(filename) == "slang-repro")
        {
            m_filenames.add(filename);
        }
    }

    Slang::List<String> m_filenames;
};

struct OptionsParser
{
    // A "translation unit" represents one or more source files
    // that are processed as a single entity when it comes to
    // semantic checking.
    //
    // For languages like HLSL, GLSL, and C, a translation unit
    // is usually a single source file (which can then go on
    // to `#include` other files into the same translation unit).
    //
    // For Slang, we support having multiple source files in
    // a single translation unit, and indeed command-line `slangc`
    // will always put all the source files into a single translation
    // unit.
    //
    // We track information on the translation units that we
    // create during options parsing, so that we can assocaite
    // other entities with these translation units:
    //
    struct RawTranslationUnit
    {
        // What language is the translation unit using?
        //
        // Note: We do not support translation units that mix
        // languages.
        //
        SlangSourceLanguage sourceLanguage;

        // Certain naming conventions imply a stage for
        // a file with only a single entry point, and in
        // those cases we will try to infer the stage from
        // the file when it is possible.
        //
        Stage impliedStage;

        // We retain the Slang API level translation unit index,
        // which we will call an "ID" inside the options parsing code.
        //
        // This will almost always be the index into the
        // `rawTranslationUnits` array below, but could conceivably,
        // be mismatched if we were parsing options for a compile
        // request that already had some translation unit(s) added
        // manually.
        //
        int                 translationUnitID;
    };
    
    // An entry point represents a function to be checked and possibly have
    // code generated in one of our translation units. An entry point
    // needs to have an associated stage, which might come via the
    // `-stage` command line option, or a `[shader("...")]` attribute
    // in the source code.
    //
    struct RawEntryPoint
    {
        String  name;
        Stage   stage = Stage::Unknown;
        int     translationUnitIndex = -1;
        int     entryPointID = -1;

        // State for tracking command-line errors
        bool conflictingStagesSet = false;
        bool redundantStageSet = false;
    };
    
    struct RawOutput
    {
        String          path;
        CodeGenTarget   impliedFormat = CodeGenTarget::Unknown;
        int             targetIndex = -1;
        int             entryPointIndex = -1;
        bool            isWholeProgram = false;
    };
    
    struct RawTarget
    {
        CodeGenTarget       format = CodeGenTarget::Unknown;
        ProfileVersion      profileVersion = ProfileVersion::Unknown;
        SlangTargetFlags    targetFlags = kDefaultTargetFlags;
        int                 targetID = -1;
        FloatingPointMode   floatingPointMode = FloatingPointMode::Default;
        bool                forceGLSLScalarLayout = false;
        List<CapabilityName> capabilityAtoms;

        // State for tracking command-line errors
        bool conflictingProfilesSet = false;
        bool redundantProfileSet = false;

    };
    
    int addTranslationUnit(SlangSourceLanguage language, Stage impliedStage);

    void addInputSlangPath(String const& path);

    void addInputForeignShaderPath(
        String const&           path,
        SlangSourceLanguage     language,
        Stage                   impliedStage);

    static Profile::RawVal findGlslProfileFromPath(const String& path);

    static SlangSourceLanguage findSourceLanguageFromPath(const String& path, Stage& outImpliedStage);

    SlangResult addInputPath(char const* inPath, SourceLanguage langOverride = SourceLanguage::Unknown);

    void addOutputPath(String const& path, CodeGenTarget impliedFormat);

    void addOutputPath(char const* inPath);
    RawEntryPoint* getCurrentEntryPoint();

    void setStage(RawEntryPoint* rawEntryPoint, Stage stage);

    RawTarget* getCurrentTarget();
    void setProfileVersion(RawTarget* rawTarget, ProfileVersion profileVersion);
    void addCapabilityAtom(RawTarget* rawTarget, CapabilityName atom);
    
    void setFloatingPointMode(RawTarget* rawTarget, FloatingPointMode mode);
    
    SlangResult parse(
        SlangCompileRequest* compileRequest,
        int             argc,
        char const* const* argv);

    SlangResult _parse(
        int             argc,
        char const* const* argv);

    static bool _passThroughRequiresStage(PassThroughMode passThrough);

    SlangResult _compileReproDirectory(SlangSession* session, EndToEndCompileRequest* originalRequest, const String& dir);

        // Pass Severity::Disabled to allow any original severity
    SlangResult _overrideDiagnostics(const UnownedStringSlice& identifierList, Severity originalSeverity, Severity overrideSeverity);

        // Pass Severity::Disabled to allow any original severity
    SlangResult _overrideDiagnostic(const UnownedStringSlice& identifier, Severity originalSeverity, Severity overrideSeverity);

    SlangResult _dumpDiagnostics(Severity originalSeverity);

    template <typename T>
    SlangResult _getValue(const CommandLineArg& arg, const UnownedStringSlice& name, T& ioValue)
    {
        CommandOptions::UserValue value;
        SLANG_RETURN_ON_FAIL(_getValue(ValueCategory(GetValueCategory<T>::Value), arg, name, value));
        ioValue = T(value);
        return SLANG_OK;
    }

    SlangResult _getValue(ValueCategory valueCategory, const CommandLineArg& arg, const UnownedStringSlice& name, CommandOptions::UserValue& outValue);
    SlangResult _getValue(ValueCategory valueCategory, const CommandLineArg& arg, CommandOptions::UserValue& outValue);
    SlangResult _getValue(const ConstArrayView<ValueCategory>& valueCategories, const CommandLineArg& arg, const UnownedStringSlice& name, ValueCategory& outCat, CommandOptions::UserValue& outValue);
    
    SlangResult _expectValue(ValueCategory valueCategory, CommandOptions::UserValue& outValue);
    SlangResult _expectInt(const CommandLineArg& arg, Int& outInt);

    template <typename T>
    SlangResult _expectValue(T& ioValue)
    {
        CommandOptions::UserValue value;
        SLANG_RETURN_ON_FAIL(_expectValue(ValueCategory(GetValueCategory<T>::Value), value));
        ioValue = T(value);
        return SLANG_OK;
    }

    void _appendUsageTitle(StringBuilder& out);
    void _appendMinimalUsage(StringBuilder& out);
    void _outputMinimalUsage();

    SlangResult _parseReferenceModule(const CommandLineArg& arg);
    SlangResult _parseReproFileSystem(const CommandLineArg& arg);
    SlangResult _parseLoadRepro(const CommandLineArg& arg);
    SlangResult _parseDebugInformation(const CommandLineArg& arg);
    SlangResult _parseProfile(const CommandLineArg& arg);
    SlangResult _parseHelp(const CommandLineArg& arg);

    SlangSession* m_session = nullptr;
    SlangCompileRequest* m_compileRequest = nullptr;

    Slang::EndToEndCompileRequest* m_requestImpl = nullptr;

    List<RawTarget> m_rawTargets;

    RawTarget m_defaultTarget;

    //
    // We collect the entry points in a "raw" array so that we can
    // possibly associate them with a stage or translation unit
    // after the fact.
    //
    List<RawEntryPoint> m_rawEntryPoints;

    // In the case where we have only a single entry point,
    // the entry point and its options might be specified out
    // of order, so we will keep a single `RawEntryPoint` around
    // and use it as the target for any state-setting options
    // before the first "proper" entry point is specified.
    RawEntryPoint m_defaultEntryPoint;

    SlangCompileFlags m_flags = 0;

    RefPtr<HLSLToVulkanLayoutOptions> m_hlslToVulkanLayoutOptions;

    List<RawTranslationUnit> m_rawTranslationUnits;

    // If we already have a translation unit for Slang code, then this will give its index.
    // If not, it will be `-1`.
    int m_slangTranslationUnitIndex = -1;

    // The number of input files that have been specified
    int m_inputPathCount = 0;

    int m_translationUnitCount = 0;
    int m_currentTranslationUnitIndex = -1;

    List<RawOutput> m_rawOutputs;

    DiagnosticSink m_parseSink;
    DiagnosticSink* m_sink = nullptr;

    FrontEndCompileRequest* m_frontEndReq = nullptr;

    SlangMatrixLayoutMode m_defaultMatrixLayoutMode = SLANG_MATRIX_LAYOUT_MODE_UNKNOWN;

        // The default archive type is zip
    SlangArchiveType m_archiveType = SLANG_ARCHIVE_TYPE_ZIP;

    bool m_compileStdLib = false;
    slang::CompileStdLibFlags m_compileStdLibFlags = 0;
    bool m_hasLoadedRepro = false;

    String m_spirvCoreGrammarJSONPath;

    bool m_allowGLSLInput = false;

    CommandLineReader m_reader;

    CommandOptionsWriter::Style m_helpStyle = CommandOptionsWriter::Style::Text;

    CommandOptions* m_cmdOptions = nullptr;
    CommandLineContext* m_cmdLineContext = nullptr;
};

int OptionsParser::addTranslationUnit(
    SlangSourceLanguage language,
    Stage               impliedStage)
{
    auto translationUnitIndex = m_rawTranslationUnits.getCount();
    auto translationUnitID = m_compileRequest->addTranslationUnit(language, nullptr);

    // As a sanity check: the API should be returning the same translation
    // unit index as we maintain internally. This invariant would only
    // be broken if we decide to support a mix of translation units specified
    // via API, and ones specified via command-line arguments.
    //
    SLANG_RELEASE_ASSERT(Index(translationUnitID) == translationUnitIndex);

    RawTranslationUnit rawTranslationUnit;
    rawTranslationUnit.sourceLanguage = language;
    rawTranslationUnit.translationUnitID = translationUnitID;
    rawTranslationUnit.impliedStage = impliedStage;

    m_rawTranslationUnits.add(rawTranslationUnit);

    return int(translationUnitIndex);
}

void OptionsParser::addInputSlangPath(
    String const& path)
{
    // All of the input .slang files will be grouped into a single logical translation unit,
    // which we create lazily when the first .slang file is encountered.
    if (m_slangTranslationUnitIndex == -1)
    {
        m_translationUnitCount++;
        m_slangTranslationUnitIndex = addTranslationUnit(SLANG_SOURCE_LANGUAGE_SLANG, Stage::Unknown);
    }

    m_compileRequest->addTranslationUnitSourceFile(m_rawTranslationUnits[m_slangTranslationUnitIndex].translationUnitID, path.begin());

    // Set the translation unit to be used by subsequent entry points
    m_currentTranslationUnitIndex = m_slangTranslationUnitIndex;
}

void OptionsParser::addInputForeignShaderPath(
    String const& path,
    SlangSourceLanguage     language,
    Stage                   impliedStage)
{
    m_translationUnitCount++;
    m_currentTranslationUnitIndex = addTranslationUnit(language, impliedStage);

    m_compileRequest->addTranslationUnitSourceFile(m_rawTranslationUnits[m_currentTranslationUnitIndex].translationUnitID, path.begin());
}

/* static */Profile::RawVal OptionsParser::findGlslProfileFromPath(const String& path)
{
    struct Entry
    {
        const char* ext;
        Profile::RawVal profileId;
    };

    static const Entry entries[] =
    {
        { ".frag", Profile::GLSL_Fragment },
        { ".geom", Profile::GLSL_Geometry },
        { ".tesc", Profile::GLSL_TessControl },
        { ".tese", Profile::GLSL_TessEval },
        { ".comp", Profile::GLSL_Compute }
    };

    for (Index i = 0; i < SLANG_COUNT_OF(entries); ++i)
    {
        const Entry& entry = entries[i];
        if (path.endsWith(entry.ext))
        {
            return entry.profileId;
        }
    }
    return Profile::Unknown;
}

/* static */SlangSourceLanguage OptionsParser::findSourceLanguageFromPath(const String& path, Stage& outImpliedStage)
{
    struct Entry
    {
        const char* ext;
        SlangSourceLanguage sourceLanguage;
        SlangStage          impliedStage;
    };

    static const Entry entries[] =
    {
        { ".slang", SLANG_SOURCE_LANGUAGE_SLANG, SLANG_STAGE_NONE },

        { ".hlsl",  SLANG_SOURCE_LANGUAGE_HLSL, SLANG_STAGE_NONE },
        { ".fx",    SLANG_SOURCE_LANGUAGE_HLSL, SLANG_STAGE_NONE },

        { ".glsl", SLANG_SOURCE_LANGUAGE_GLSL,  SLANG_STAGE_NONE },
        { ".vert", SLANG_SOURCE_LANGUAGE_GLSL,  SLANG_STAGE_VERTEX },
        { ".frag", SLANG_SOURCE_LANGUAGE_GLSL,  SLANG_STAGE_FRAGMENT },
        { ".geom", SLANG_SOURCE_LANGUAGE_GLSL,  SLANG_STAGE_GEOMETRY },
        { ".tesc", SLANG_SOURCE_LANGUAGE_GLSL,  SLANG_STAGE_HULL },
        { ".tese", SLANG_SOURCE_LANGUAGE_GLSL,  SLANG_STAGE_DOMAIN },
        { ".comp", SLANG_SOURCE_LANGUAGE_GLSL,  SLANG_STAGE_COMPUTE },
        { ".mesh", SLANG_SOURCE_LANGUAGE_GLSL,  SLANG_STAGE_MESH },
        { ".task", SLANG_SOURCE_LANGUAGE_GLSL,  SLANG_STAGE_AMPLIFICATION },

        { ".c",    SLANG_SOURCE_LANGUAGE_C,     SLANG_STAGE_NONE },
        { ".cpp",  SLANG_SOURCE_LANGUAGE_CPP,   SLANG_STAGE_NONE },
        { ".cu",   SLANG_SOURCE_LANGUAGE_CUDA,  SLANG_STAGE_NONE }

    };

    for (Index i = 0; i < SLANG_COUNT_OF(entries); ++i)
    {
        const Entry& entry = entries[i];
        if (path.endsWith(entry.ext))
        {
            outImpliedStage = Stage(entry.impliedStage);
            return entry.sourceLanguage;
        }
    }
    return SLANG_SOURCE_LANGUAGE_UNKNOWN;
}

SlangResult OptionsParser::addInputPath(char const* inPath, SourceLanguage langOverride )
{
    m_inputPathCount++;

    // look at the extension on the file name to determine
    // how we should handle it.
    String path = String(inPath);

    if (path.endsWith(".slang") || langOverride == SourceLanguage::Slang)
    {
        // Plain old slang code
        addInputSlangPath(path);
        return SLANG_OK;
    }

    Stage impliedStage = Stage::Unknown;
    SlangSourceLanguage sourceLanguage = langOverride == SourceLanguage::Unknown ? findSourceLanguageFromPath(path, impliedStage) : SlangSourceLanguage(langOverride);

    if (sourceLanguage == SLANG_SOURCE_LANGUAGE_UNKNOWN)
    {
        m_requestImpl->getSink()->diagnose(SourceLoc(), Diagnostics::cannotDeduceSourceLanguage, inPath);
        return SLANG_FAIL;
    }

    addInputForeignShaderPath(path, sourceLanguage, impliedStage);

    return SLANG_OK;
}

void OptionsParser::addOutputPath(
    String const& path,
    CodeGenTarget   impliedFormat)
{
    RawOutput rawOutput;
    rawOutput.path = path;
    rawOutput.impliedFormat = impliedFormat;
    m_rawOutputs.add(rawOutput);
}

void OptionsParser::addOutputPath(char const* inPath)
{
    String path = String(inPath);
    String ext = Path::getPathExt(path);

    if (ext == toSlice("slang-module") ||
        ext == toSlice("slang-lib") ||
        ext == toSlice("dir") ||
        ext == toSlice("zip"))
    {
        // These extensions don't indicate a artifact container, just that we want to emit IR
        if (ext == toSlice("slang-module") ||
            ext == toSlice("slang-lib"))
        {
            // We want to emit IR 
            m_requestImpl->m_emitIr = true;
        }
        else
        {
            // We want to write out in an artfact "container", that can hold multiple artifacts.
            m_compileRequest->setOutputContainerFormat(SLANG_CONTAINER_FORMAT_SLANG_MODULE);
        }

        m_requestImpl->m_containerOutputPath = path;
    }
    else
    {
        const SlangCompileTarget target = TypeTextUtil::findCompileTargetFromExtension(ext.getUnownedSlice());
        // If the target is not found the value returned is Unknown. This is okay because
        // we allow an unknown-format `-o`, assuming we get a target format
        // from another argument.
        addOutputPath(path, CodeGenTarget(target));
    }
}

OptionsParser::RawEntryPoint* OptionsParser::getCurrentEntryPoint()
{
    auto rawEntryPointCount = m_rawEntryPoints.getCount();
    return rawEntryPointCount ? &m_rawEntryPoints[rawEntryPointCount - 1] : &m_defaultEntryPoint;
}

void OptionsParser::setStage(RawEntryPoint* rawEntryPoint, Stage stage)
{
    if (rawEntryPoint->stage != Stage::Unknown)
    {
        rawEntryPoint->redundantStageSet = true;
        if (stage != rawEntryPoint->stage)
        {
            rawEntryPoint->conflictingStagesSet = true;
        }
    }
    rawEntryPoint->stage = stage;
}

OptionsParser::RawTarget* OptionsParser::getCurrentTarget()
{
    auto rawTargetCount = m_rawTargets.getCount();
    return rawTargetCount ? &m_rawTargets[rawTargetCount - 1] : &m_defaultTarget;
}

void OptionsParser::setProfileVersion(RawTarget* rawTarget, ProfileVersion profileVersion)
{
    if (rawTarget->profileVersion != ProfileVersion::Unknown)
    {
        rawTarget->redundantProfileSet = true;

        if (profileVersion != rawTarget->profileVersion)
        {
            rawTarget->conflictingProfilesSet = true;
        }
    }
    rawTarget->profileVersion = profileVersion;
}

void OptionsParser::addCapabilityAtom(RawTarget* rawTarget, CapabilityName atom)
{
    rawTarget->capabilityAtoms.add(atom);
}

void OptionsParser::setFloatingPointMode(RawTarget* rawTarget, FloatingPointMode mode)
{
    rawTarget->floatingPointMode = mode;
}

/* static */bool OptionsParser::_passThroughRequiresStage(PassThroughMode passThrough)
{
    switch (passThrough)
    {
        case PassThroughMode::Glslang:
        case PassThroughMode::Dxc:
        case PassThroughMode::Fxc:
        {
            return true;
        }
        default:
        {
            return false;
        }
    }
}

static SlangResult _loadRepro(const String& path, DiagnosticSink* sink, EndToEndCompileRequest* request)
{
    List<uint8_t> buffer;
    SLANG_RETURN_ON_FAIL(ReproUtil::loadState(path, sink, buffer));

    auto requestState = ReproUtil::getRequest(buffer);
    MemoryOffsetBase base;
    base.set(buffer.getBuffer(), buffer.getCount());

    // If we can find a directory, that exists, we will set up a file system to load from that directory
    ComPtr<ISlangFileSystem> optionalFileSystem;
    String dirPath;
    if (SLANG_SUCCEEDED(ReproUtil::calcDirectoryPathFromFilename(path, dirPath)))
    {
        SlangPathType pathType;
        if (SLANG_SUCCEEDED(Path::getPathType(dirPath, &pathType)) && pathType == SLANG_PATH_TYPE_DIRECTORY)
        {
            optionalFileSystem = new RelativeFileSystem(OSFileSystem::getExtSingleton(), dirPath);
        }
    }

    SLANG_RETURN_ON_FAIL(ReproUtil::load(base, requestState, optionalFileSystem, request));

    return SLANG_OK;
}

SlangResult OptionsParser::_compileReproDirectory(SlangSession* session, EndToEndCompileRequest* originalRequest, const String& dir)
{
    auto stdOut = originalRequest->getWriter(WriterChannel::StdOutput);

    ReproPathVisitor visitor;
    Path::find(dir, nullptr, &visitor);

    for (auto filename : visitor.m_filenames)
    {
        // Create a fresh request
        ComPtr<slang::ICompileRequest> request;
        SLANG_RETURN_ON_FAIL(session->createCompileRequest(request.writeRef()));

        auto requestImpl = asInternal(request);

        // Copy over the fallback file system
        requestImpl->m_reproFallbackFileSystem = originalRequest->m_reproFallbackFileSystem;

        // Load the repro into it
        auto path = Path::combine(dir, filename);

        if (SLANG_FAILED(_loadRepro(path, m_sink, requestImpl)))
        {
            if (stdOut)
            {
                StringBuilder buf;
                buf << filename << " - Failed to load!\n";
            }
            continue;
        }

        if (stdOut)
        {
            StringBuilder buf;
            buf << filename << "\n";
            stdOut->write(buf.getBuffer(), buf.getLength());
        }

        StringBuilder bufs[Index(WriterChannel::CountOf)];
        ComPtr<ISlangWriter> writers[Index(WriterChannel::CountOf)];
        for (Index i = 0; i < Index(WriterChannel::CountOf); ++i)
        {
            writers[i] = new StringWriter(&bufs[0], 0);
            requestImpl->setWriter(WriterChannel(i), writers[i]);
        }

        if (SLANG_FAILED(requestImpl->compile()))
        {
            const char failed[] = "FAILED!\n";
            stdOut->write(failed, SLANG_COUNT_OF(failed) - 1);

            const auto& diagnostics = bufs[Index(WriterChannel::Diagnostic)];

            stdOut->write(diagnostics.getBuffer(), diagnostics.getLength());

            return SLANG_FAIL;
        }
    }

    if (stdOut)
    {
        const char end[] = "(END)\n";
        stdOut->write(end, SLANG_COUNT_OF(end) - 1);
    }

    return SLANG_OK;
}

SlangResult OptionsParser::_overrideDiagnostics(const UnownedStringSlice& identifierList, Severity originalSeverity, Severity overrideSeverity)
{
    List<UnownedStringSlice> slices;
    StringUtil::split(identifierList, ',', slices);

    for (const auto& slice : slices)
    {
        SLANG_RETURN_ON_FAIL(_overrideDiagnostic(slice, originalSeverity, overrideSeverity));
    }
    return SLANG_OK;
}

SlangResult OptionsParser::_overrideDiagnostic(const UnownedStringSlice& identifier, Severity originalSeverity, Severity overrideSeverity)
{
    auto diagnosticsLookup = getDiagnosticsLookup();

    const DiagnosticInfo* diagnostic = nullptr;
    Int diagnosticId = -1;

    // If it starts with a digit we assume it a number 
    if (identifier.getLength() > 0 && (CharUtil::isDigit(identifier[0]) || identifier[0] == '-'))
    {
        if (SLANG_FAILED(StringUtil::parseInt(identifier, diagnosticId)))
        {
            m_sink->diagnose(SourceLoc(), Diagnostics::unknownDiagnosticName, identifier);
            return SLANG_FAIL;
        }

        // If we use numbers, we don't worry if we can't find a diagnostic
        // and silently ignore. This was the previous behavior, and perhaps
        // provides a way to safely disable warnings, without worrying about
        // the version of the compiler.
        diagnostic = diagnosticsLookup->getDiagnosticById(diagnosticId);
    }
    else
    {
        diagnostic = diagnosticsLookup->findDiagnosticByName(identifier);
        if (!diagnostic)
        {
            m_sink->diagnose(SourceLoc(), Diagnostics::unknownDiagnosticName, identifier);
            return SLANG_FAIL;
        }
        diagnosticId = diagnostic->id;
    }

    // If we are only allowing certain original severities check it's the right type
    if (diagnostic && originalSeverity != Severity::Disable && diagnostic->severity != originalSeverity)
    {
        // Strictly speaking the diagnostic name is known, but it's not the right severity
        // to be converted from, so it is an 'unknown name' in the context of severity...
        // Or perhaps we want another diagnostic
        m_sink->diagnose(SourceLoc(), Diagnostics::unknownDiagnosticName, identifier);
        return SLANG_FAIL;
    }

    // Override the diagnostic severity in the sink
    m_requestImpl->getSink()->overrideDiagnosticSeverity(int(diagnosticId), overrideSeverity, diagnostic);

    return SLANG_OK;
}

SlangResult OptionsParser::_dumpDiagnostics(Severity originalSeverity)
{
    // Get the diagnostics and dump them
    auto diagnosticsLookup = getDiagnosticsLookup();

    StringBuilder buf;

    for (const auto& diagnostic : diagnosticsLookup->getDiagnostics())
    {
        if (originalSeverity != Severity::Disable &&
            diagnostic->severity != originalSeverity)
        {
            continue;
        }

        buf.clear();

        buf << diagnostic->id << " : ";
        NameConventionUtil::convert(NameStyle::Camel, UnownedStringSlice(diagnostic->name), NameConvention::LowerKabab, buf);
        buf << "\n";
        m_sink->diagnoseRaw(Severity::Note, buf.getUnownedSlice());
    }

    return SLANG_OK;
}

void OptionsParser::_appendUsageTitle(StringBuilder& out)
{
    out << "Usage: slangc [options...] [--] <input files>\n\n";
}

void OptionsParser::_outputMinimalUsage()
{
    // Output usage info
    StringBuilder buf;
    _appendMinimalUsage(buf);

    m_sink->diagnoseRaw(Severity::Note, buf.getUnownedSlice());
}

void OptionsParser::_appendMinimalUsage(StringBuilder& out)
{
    _appendUsageTitle(out);
    out << "For help: slangc -h\n";
}


SlangResult OptionsParser::_getValue(ValueCategory valueCategory, const CommandLineArg& arg, const UnownedStringSlice& name, CommandOptions::UserValue& outValue)
{
    const auto optionIndex = m_cmdOptions->findOptionByCategoryUserValue(CommandOptions::UserValue(valueCategory), name);
    if (optionIndex < 0)
    {
        const auto categoryIndex = m_cmdOptions->findCategoryByUserValue(CommandOptions::UserValue(valueCategory));
        SLANG_ASSERT(categoryIndex >= 0);
        if (categoryIndex < 0)
        {
            return SLANG_FAIL;
        }

        List<UnownedStringSlice> names;
        m_cmdOptions->getCategoryOptionNames(categoryIndex, names);

        StringBuilder buf;
        StringUtil::join(names.getBuffer(), names.getCount(), toSlice(", "), buf);

        m_sink->diagnose(arg.loc, Diagnostics::unknownCommandLineValue, buf);
        return SLANG_FAIL;
    }

    outValue = m_cmdOptions->getOptionAt(optionIndex).userValue;
    return SLANG_OK;
}

SlangResult OptionsParser::_getValue(ValueCategory valueCategory, const CommandLineArg& arg, CommandOptions::UserValue& outValue)
{
    return _getValue(valueCategory, arg, arg.value.getUnownedSlice(), outValue);
}

SlangResult OptionsParser::_getValue(const ConstArrayView<ValueCategory>& valueCategories, const CommandLineArg& arg, const UnownedStringSlice& name, ValueCategory& outCat, CommandOptions::UserValue& outValue)
{
    auto& cmdOptions = asInternal(m_session)->m_commandOptions;

    for (auto valueCategory : valueCategories)
    {
        const auto optionIndex = cmdOptions.findOptionByCategoryUserValue(CommandOptions::UserValue(valueCategory), name);
        if (optionIndex >= 0)
        {
            outCat = valueCategory;
            outValue = cmdOptions.getOptionAt(optionIndex).userValue;
            return SLANG_OK;
        }
    }

    List<UnownedStringSlice> names;
    for (auto valueCategory : valueCategories)
    {
        const auto categoryIndex = cmdOptions.findCategoryByUserValue(CommandOptions::UserValue(valueCategory));
        SLANG_ASSERT(categoryIndex >= 0);
        if (categoryIndex < 0)
        {
            return SLANG_FAIL;
        }
        cmdOptions.appendCategoryOptionNames(categoryIndex, names);
    }

    StringBuilder buf;
    StringUtil::join(names.getBuffer(), names.getCount(), toSlice(", "), buf);

    m_sink->diagnose(arg.loc, Diagnostics::unknownCommandLineValue, buf);
    return SLANG_FAIL;
}

SlangResult OptionsParser::_expectValue(ValueCategory valueCategory, CommandOptions::UserValue& outValue)
{
    CommandLineArg arg;
    SLANG_RETURN_ON_FAIL(m_reader.expectArg(arg));
    SLANG_RETURN_ON_FAIL(_getValue(valueCategory, arg, outValue));
    return SLANG_OK;
}

SlangResult OptionsParser::_expectInt(const CommandLineArg& initArg, Int& outInt)
{
    SLANG_UNUSED(initArg);

    CommandLineArg arg;
    SLANG_RETURN_ON_FAIL(m_reader.expectArg(arg));
    
    if (SLANG_FAILED(StringUtil::parseInt(arg.value.getUnownedSlice(), outInt)))
    {
        m_sink->diagnose(arg.loc, Diagnostics::expectingAnInteger);
        return SLANG_FAIL;
    }
    return SLANG_OK;
}

SlangResult OptionsParser::_parseReferenceModule(const CommandLineArg& arg)
{
    SLANG_UNUSED(arg);

    CommandLineArg referenceModuleName;
    SLANG_RETURN_ON_FAIL(m_reader.expectArg(referenceModuleName));

    const auto path = referenceModuleName.value;

    auto desc = ArtifactDescUtil::getDescFromPath(path.getUnownedSlice());

    if (desc.kind == ArtifactKind::Unknown)
    {
        m_sink->diagnose(referenceModuleName.loc, Diagnostics::unknownLibraryKind, Path::getPathExt(path));
        return SLANG_FAIL;
    }

    // If it's a GPU binary, then we'll assume it's a library
    if (ArtifactDescUtil::isGpuUsable(desc))
    {
        desc.kind = ArtifactKind::Library;
    }

    // If its a zip we'll *assume* its a zip holding compilation results
    if (desc.kind == ArtifactKind::Zip)
    {
        desc.payload = ArtifactPayload::CompileResults;
    }

    if (!ArtifactDescUtil::isLinkable(desc))
    {
        m_sink->diagnose(referenceModuleName.loc, Diagnostics::kindNotLinkable, Path::getPathExt(path));
        return SLANG_FAIL;
    }

    const String name = ArtifactDescUtil::getBaseNameFromPath(desc, path.getUnownedSlice());

    // Create the artifact
    auto artifact = Artifact::create(desc, name.getUnownedSlice());

    // There is a problem here if I want to reference a library that is a 'system' library or is not directly a file
    // In that case the path shouldn't be set and the name should completely define the library.
    // Seeing as on all targets the baseName doesn't have an extension, and all library types do
    // if the name doesn't have an extension we can assume there is no path to it.

    ComPtr<IOSFileArtifactRepresentation> fileRep;
    if (Path::getPathExt(path).getLength() <= 0)
    {
        // If there is no extension *assume* it is the name of a system level library
        fileRep = new OSFileArtifactRepresentation(IOSFileArtifactRepresentation::Kind::NameOnly, path.getUnownedSlice(), nullptr);
    }
    else
    {
        fileRep = new OSFileArtifactRepresentation(IOSFileArtifactRepresentation::Kind::Reference, path.getUnownedSlice(), nullptr);
        if (!fileRep->exists())
        {
            m_sink->diagnose(referenceModuleName.loc, Diagnostics::libraryDoesNotExist, path);
            return SLANG_FAIL;
        }
    }
    artifact->addRepresentation(fileRep);

    SLANG_RETURN_ON_FAIL(_addLibraryReference(m_requestImpl, artifact));
    return SLANG_OK;
}

SlangResult OptionsParser::_parseReproFileSystem(const CommandLineArg& arg)
{
    SLANG_UNUSED(arg);

    CommandLineArg reproName;
    SLANG_RETURN_ON_FAIL(m_reader.expectArg(reproName));

    List<uint8_t> buffer;
    {
        const Result res = ReproUtil::loadState(reproName.value, m_sink, buffer);
        if (SLANG_FAILED(res))
        {
            m_sink->diagnose(reproName.loc, Diagnostics::unableToReadFile, reproName.value);
            return res;
        }
    }

    auto requestState = ReproUtil::getRequest(buffer);
    MemoryOffsetBase base;
    base.set(buffer.getBuffer(), buffer.getCount());

    // If we can find a directory, that exists, we will set up a file system to load from that directory
    ComPtr<ISlangFileSystem> dirFileSystem;
    String dirPath;
    if (SLANG_SUCCEEDED(ReproUtil::calcDirectoryPathFromFilename(reproName.value, dirPath)))
    {
        SlangPathType pathType;
        if (SLANG_SUCCEEDED(Path::getPathType(dirPath, &pathType)) && pathType == SLANG_PATH_TYPE_DIRECTORY)
        {
            dirFileSystem = new RelativeFileSystem(OSFileSystem::getExtSingleton(), dirPath, true);
        }
    }

    ComPtr<ISlangFileSystemExt> fileSystem;
    SLANG_RETURN_ON_FAIL(ReproUtil::loadFileSystem(base, requestState, dirFileSystem, fileSystem));

    auto cacheFileSystem = as<CacheFileSystem>(fileSystem);
    SLANG_ASSERT(cacheFileSystem);

    // I might want to make the dir file system the fallback file system...
    cacheFileSystem->setInnerFileSystem(dirFileSystem, cacheFileSystem->getUniqueIdentityMode(), cacheFileSystem->getPathStyle());

    // Set as the file system
    m_compileRequest->setFileSystem(fileSystem);
    return SLANG_OK;
}

SlangResult OptionsParser::_parseHelp(const CommandLineArg& arg)
{
    SLANG_UNUSED(arg);

    Index categoryIndex = -1;

    if (m_reader.hasArg())
    {
        auto catArg = m_reader.getArgAndAdvance();

        categoryIndex = m_cmdOptions->findCategoryByCaseInsensitiveName(catArg.value.getUnownedSlice());
        if (categoryIndex < 0)
        {
            m_sink->diagnose(catArg.loc, Diagnostics::unknownHelpCategory);
            return SLANG_FAIL;
        }
    }

    CommandOptionsWriter::Options writerOptions;
    writerOptions.style = m_helpStyle;

    auto writer = CommandOptionsWriter::create(writerOptions);

    auto& buf = writer->getBuilder();

    if (categoryIndex < 0)
    {
        // If it's the text style we can inject usage at the top
        if (m_helpStyle == CommandOptionsWriter::Style::Text)
        {
            _appendUsageTitle(buf);
        }
        else
        {
            // NOTE! We need this preamble because if we have links,
            // we have to make sure the first thing in markdown *isn't* <>

            buf << "# Slang Command Line Options\n\n";
            buf << "*Usage:*\n";
            buf << "```\n";
            buf << "slangc [options...] [--] <input files>\n\n";
            buf << "# For help\n";
            buf << "slangc -h\n\n";
            buf << "# To generate this file\n";
            buf << "slangc -help-style markdown -h\n";
            buf << "```\n";
        }

        writer->appendDescription(m_cmdOptions);
    }
    else
    {
        writer->appendDescriptionForCategory(m_cmdOptions, categoryIndex);
    }

    m_sink->diagnoseRaw(Severity::Note, buf.getBuffer());

    return SLANG_OK;
}

SlangResult OptionsParser::_parseLoadRepro(const CommandLineArg& arg)
{
    SLANG_UNUSED(arg);

    CommandLineArg reproName;
    SLANG_RETURN_ON_FAIL(m_reader.expectArg(reproName));

    if (SLANG_FAILED(_loadRepro(reproName.value, m_sink, m_requestImpl)))
    {
        m_sink->diagnose(reproName.loc, Diagnostics::unableToReadFile, reproName.value);
        return SLANG_FAIL;
    }

    m_hasLoadedRepro = true;
    return SLANG_OK;
}

SlangResult OptionsParser::_parseDebugInformation(const CommandLineArg& arg)
{
    auto name = arg.value.getUnownedSlice().tail(2);

    // Note: unlike with `-O` above, we have to consider that other
    // options might have names that start with `-g` and so cannot
    // just detect it as a prefix.
    if (name.getLength() == 0)
    {
        // The default is standard
        m_compileRequest->setDebugInfoLevel(SLANG_DEBUG_INFO_LEVEL_STANDARD);
    }
    else
    {
        CommandOptions::UserValue value;
        ValueCategory valueCat;
        ValueCategory valueCats[] = { ValueCategory::DebugLevel, ValueCategory::DebugInfoFormat };
        SLANG_RETURN_ON_FAIL(_getValue(makeConstArrayView(valueCats), arg, name, valueCat, value));

        if (valueCat == ValueCategory::DebugLevel)
        {
            const auto level = (SlangDebugInfoLevel)value;
            m_compileRequest->setDebugInfoLevel(level);
        }
        else
        {
            const auto debugFormat = (SlangDebugInfoFormat)value;
            m_compileRequest->setDebugInfoFormat(debugFormat);
        }
    }
    return SLANG_OK;
}


SlangResult OptionsParser::_parseProfile(const CommandLineArg& arg)
{
    SLANG_UNUSED(arg);

    // A "profile" can specify both a general capability level for
    // a target, and also (as a legacy/compatibility feature) a
    // specific stage to use for an entry point.

    CommandLineArg operand;
    SLANG_RETURN_ON_FAIL(m_reader.expectArg(operand));

    // A a convenience, the `-profile` option supports an operand that consists
    // of multiple tokens separated with `+`. The eventual goal is that each
    // of these tokens will represent a capability that should be assumed to
    // be present on the target.
    //
    List<UnownedStringSlice> slices;
    StringUtil::split(operand.value.getUnownedSlice(), '+', slices);
    Index sliceCount = slices.getCount();

    // For now, we will require that the *first* capability in the list is
    // special, and represents the traditional `Profile` to compile for in
    // the existing Slang model.
    //
    UnownedStringSlice profileName = sliceCount >= 1 ? slices[0] : UnownedTerminatedStringSlice("");

    SlangProfileID profileID = SlangProfileID(Slang::Profile::lookUp(profileName).raw);
    if (profileID == SLANG_PROFILE_UNKNOWN)
    {
        m_sink->diagnose(operand.loc, Diagnostics::unknownProfile, profileName);
        return SLANG_FAIL;
    }
    else
    {
        auto profile = Profile(profileID);

        setProfileVersion(getCurrentTarget(), profile.getVersion());

        // A `-profile` option that also specifies a stage (e.g., `-profile vs_5_0`)
        // should be treated like a composite (e.g., `-profile sm_5_0 -stage vertex`)
        auto stage = profile.getStage();
        if (stage != Stage::Unknown)
        {
            setStage(getCurrentEntryPoint(), stage);
        }
    }

    // Any additional capability tokens will be assumed to represent `CapabilityAtom`s.
    // Those atoms will need to be added to the supported capabilities of the target.
    // 
    for (Index i = 1; i < sliceCount; ++i)
    {
        UnownedStringSlice atomName = slices[i];
        CapabilityName atom = findCapabilityName(atomName);
        if (atom == CapabilityName::Invalid)
        {
            m_sink->diagnose(operand.loc, Diagnostics::unknownProfile, atomName);
            return SLANG_FAIL;
        }

        addCapabilityAtom(getCurrentTarget(), atom);
    }

    return SLANG_OK;
}

SlangResult OptionsParser::_parse(
    int             argc,
    char const* const* argv)
{
    // Copy some state out of the current request, in case we've been called
    // after some other initialization has been performed.
    m_flags = m_requestImpl->getFrontEndReq()->compileFlags;

    // Set up the args
    CommandLineArgs args(m_cmdLineContext);
    // Converts input args into args in 'args'.
    // Doing so will allocate some SourceLoc space from the CommandLineContext.
    args.setArgs(argv, argc);

    {
        auto linkage = m_requestImpl->getLinkage();
        // Before we do anything else lets strip out all of the downstream arguments.
        SLANG_RETURN_ON_FAIL(linkage->m_downstreamArgs.stripDownstreamArgs(args, 0, m_sink));
    }

    m_reader.init(&args, m_sink);

    while (m_reader.hasArg())
    {
        auto arg = m_reader.getArgAndAdvance();
        const auto& argValue = arg.value;

        // If it's not an option we assume it's a path
        if (argValue[0] != '-')
        {
            SLANG_RETURN_ON_FAIL(addInputPath(argValue.getBuffer()));
            continue;
        }

        const Index optionIndex = m_cmdOptions->findOptionByName(argValue.getUnownedSlice());

        if (optionIndex < 0)
        {
            m_sink->diagnose(arg.loc, Diagnostics::unknownCommandLineOption, argValue);
            _outputMinimalUsage();
            return SLANG_FAIL;
        }

        const auto optionKind = OptionKind(m_cmdOptions->getOptionAt(optionIndex).userValue);

        switch (optionKind)
        {
            case OptionKind::NoMangle: m_flags |= SLANG_COMPILE_FLAG_NO_MANGLING; break;
            case OptionKind::AllowGLSL: m_allowGLSLInput = true; break;
            case OptionKind::EmitIr: m_requestImpl->m_emitIr = true; break;
            case OptionKind::LoadStdLib:
            {
                CommandLineArg fileName;
                SLANG_RETURN_ON_FAIL(m_reader.expectArg(fileName));

                // Load the file
                ScopedAllocation contents;
                SLANG_RETURN_ON_FAIL(File::readAllBytes(fileName.value, contents));
                SLANG_RETURN_ON_FAIL(m_session->loadStdLib(contents.getData(), contents.getSizeInBytes()));
                break;
            }
            case OptionKind::CompileStdLib: m_compileStdLib = true; break;
            case OptionKind::ArchiveType:   SLANG_RETURN_ON_FAIL(_expectValue(m_archiveType)); break;
            case OptionKind::SaveStdLib:
            {
                CommandLineArg fileName;
                SLANG_RETURN_ON_FAIL(m_reader.expectArg(fileName));

                ComPtr<ISlangBlob> blob;

                SLANG_RETURN_ON_FAIL(m_session->saveStdLib(m_archiveType, blob.writeRef()));
                SLANG_RETURN_ON_FAIL(File::writeAllBytes(fileName.value, blob->getBufferPointer(), blob->getBufferSize()));
                break;
            }
            case OptionKind::SaveStdLibBinSource:
            {
                CommandLineArg fileName;
                SLANG_RETURN_ON_FAIL(m_reader.expectArg(fileName));

                ComPtr<ISlangBlob> blob;

                SLANG_RETURN_ON_FAIL(m_session->saveStdLib(m_archiveType, blob.writeRef()));

                StringBuilder builder;
                StringWriter writer(&builder, 0);

                SLANG_RETURN_ON_FAIL(HexDumpUtil::dumpSourceBytes((const uint8_t*)blob->getBufferPointer(), blob->getBufferSize(), 16, &writer));

                File::writeAllText(fileName.value, builder);
                break;
            }
            case OptionKind::NoCodeGen: m_flags |= SLANG_COMPILE_FLAG_NO_CODEGEN; break;
            case OptionKind::DumpIntermediates: m_compileRequest->setDumpIntermediates(true); break;
            case OptionKind::DumpIrIds:
            {
                m_frontEndReq->m_irDumpOptions.flags |= IRDumpOptions::Flag::DumpDebugIds;
                break;
            }
            case OptionKind::DumpIntermediatePrefix:
            {
                CommandLineArg prefix;
                SLANG_RETURN_ON_FAIL(m_reader.expectArg(prefix));
                m_requestImpl->m_dumpIntermediatePrefix = prefix.value;
                break;
            }
            case OptionKind::OutputIncludes: m_frontEndReq->outputIncludes = true; break;
            case OptionKind::DumpIr: m_frontEndReq->shouldDumpIR = true; break;
            case OptionKind::PreprocessorOutput: m_frontEndReq->outputPreprocessor = true; break;
            case OptionKind::DumpAst: m_frontEndReq->shouldDumpAST = true; break;
            case OptionKind::Doc:
            {
                // If compiling stdlib is enabled, will write out documentation
                m_compileStdLibFlags |= slang::CompileStdLibFlag::WriteDocumentation;

                // Enable writing out documentation on the req
                m_frontEndReq->shouldDocument = true;
                break;
            }
            case OptionKind::DumpRepro:
            {
                CommandLineArg dumpRepro;
                SLANG_RETURN_ON_FAIL(m_reader.expectArg(dumpRepro));
                m_requestImpl->m_dumpRepro = dumpRepro.value;
                m_compileRequest->enableReproCapture();
                break;
            }
            case OptionKind::DumpReproOnError: m_requestImpl->m_dumpReproOnError = true; break;
            case OptionKind::ExtractRepro:
            {
                CommandLineArg reproName;
                SLANG_RETURN_ON_FAIL(m_reader.expectArg(reproName));

                {
                    const Result res = ReproUtil::extractFilesToDirectory(reproName.value, m_sink);
                    if (SLANG_FAILED(res))
                    {
                        m_sink->diagnose(reproName.loc, Diagnostics::unableExtractReproToDirectory, reproName.value);
                        return res;
                    }
                }
                break;
            }
            case OptionKind::ReportDownstreamTime:
            {
                m_compileRequest->setReportDownstreamTime(true);
                break;
            }
            case OptionKind::ReportPerfBenchmark:
            {
                m_compileRequest->setReportPerfBenchmark(true);
                break;
            }
            case OptionKind::ModuleName:
            {
                CommandLineArg moduleName;
                SLANG_RETURN_ON_FAIL(m_reader.expectArg(moduleName));

                m_compileRequest->setDefaultModuleName(moduleName.value.getBuffer());
                break;
            }
            case OptionKind::LoadRepro: SLANG_RETURN_ON_FAIL(_parseLoadRepro(arg)); break;
            case OptionKind::LoadReproDirectory:
            {
                CommandLineArg reproDirectory;
                SLANG_RETURN_ON_FAIL(m_reader.expectArg(reproDirectory));

                SLANG_RETURN_ON_FAIL(_compileReproDirectory(m_session, m_requestImpl, reproDirectory.value));
                break;
            }
            case OptionKind::ReproFallbackDirectory:
            {
                CommandLineArg reproDirectory;
                SLANG_RETURN_ON_FAIL(m_reader.expectArg(reproDirectory));

                if (reproDirectory.value == toSlice("default:"))
                {
                    // The default is to use the OS file system
                    m_requestImpl->m_reproFallbackFileSystem = OSFileSystem::getExtSingleton();
                }
                else if (reproDirectory.value == toSlice("none:"))
                {
                    // None, means that there isn't a fallback
                    m_requestImpl->m_reproFallbackFileSystem.setNull();
                }
                else
                {
                    auto osFileSystem = OSFileSystem::getExtSingleton();

                    SlangPathType pathType;
                    if (SLANG_FAILED(osFileSystem->getPathType(reproDirectory.value.getBuffer(), &pathType) )
                        || pathType != SLANG_PATH_TYPE_DIRECTORY)
                    {
                        return SLANG_FAIL;
                    }
                    // Make the fallback directory use a relative file system, to the specified directory
                    m_requestImpl->m_reproFallbackFileSystem = new RelativeFileSystem(osFileSystem, reproDirectory.value);
                }
                break;
            }
            case OptionKind::ReproFileSystem: SLANG_RETURN_ON_FAIL(_parseReproFileSystem(arg)); break;
            case OptionKind::SerialIr: m_frontEndReq->useSerialIRBottleneck = true; break;
            case OptionKind::DisableSpecialization: m_requestImpl->disableSpecialization = true; break;
            case OptionKind::DisableDynamicDispatch: m_requestImpl->disableDynamicDispatch = true; break;
            case OptionKind::TrackLiveness: m_requestImpl->setTrackLiveness(true); break;
            case OptionKind::VerbosePaths: m_requestImpl->getSink()->setFlag(DiagnosticSink::Flag::VerbosePath); break;
            case OptionKind::DumpWarningDiagnostics: _dumpDiagnostics(Severity::Warning); break;
            case OptionKind::WarningsAsErrors:
            {
                CommandLineArg operand;
                SLANG_RETURN_ON_FAIL(m_reader.expectArg(operand));

                if (operand.value == "all")
                {
                    // TODO(JS):
                    // Perhaps there needs to be a way to disable this selectively.
                    m_requestImpl->getSink()->setFlag(DiagnosticSink::Flag::TreatWarningsAsErrors);
                }
                else
                {
                    SLANG_RETURN_ON_FAIL(_overrideDiagnostics(operand.value.getUnownedSlice(), Severity::Warning, Severity::Error));
                }
                break;
            }
            case OptionKind::DisableWarnings:
            {
                CommandLineArg operand;
                SLANG_RETURN_ON_FAIL(m_reader.expectArg(operand));
                SLANG_RETURN_ON_FAIL(_overrideDiagnostics(operand.value.getUnownedSlice(), Severity::Warning, Severity::Disable));
                break;
            }
            case OptionKind::DisableWarning:
            {
                // 5 because -Wno-
                auto name = argValue.getUnownedSlice().tail(5);
                SLANG_RETURN_ON_FAIL(_overrideDiagnostic(name, Severity::Warning, Severity::Disable));
                break;
            }
            case OptionKind::EnableWarning:
            {
                // 2 because -W
                auto name = argValue.getUnownedSlice().tail(2);
                // Enable the warning
                SLANG_RETURN_ON_FAIL(_overrideDiagnostic(name, Severity::Warning, Severity::Warning));
                break;
            }
            case OptionKind::VerifyDebugSerialIr: m_frontEndReq->verifyDebugSerialization = true; break;
            case OptionKind::ValidateIr: m_frontEndReq->shouldValidateIR = true; break;
            case OptionKind::SkipCodeGen: m_requestImpl->m_shouldSkipCodegen = true; break;
            case OptionKind::ParameterBlocksUseRegisterSpaces:
            {
                getCurrentTarget()->targetFlags |= SLANG_TARGET_FLAG_PARAMETER_BLOCKS_USE_REGISTER_SPACES;
                break;
            }
            case OptionKind::IrCompression:
            {
                CommandLineArg name;
                SLANG_RETURN_ON_FAIL(m_reader.expectArg(name));

                SLANG_RETURN_ON_FAIL(SerialParseUtil::parseCompressionType(name.value.getUnownedSlice(), m_requestImpl->getLinkage()->serialCompressionType));
                break;
            }
            case OptionKind::Target:
            {
                CommandLineArg name;
                SLANG_RETURN_ON_FAIL(m_reader.expectArg(name));

                const CodeGenTarget format = (CodeGenTarget)TypeTextUtil::findCompileTargetFromName(name.value.getUnownedSlice());

                if (format == CodeGenTarget::Unknown)
                {
                    m_sink->diagnose(name.loc, Diagnostics::unknownCodeGenerationTarget, name.value);
                    return SLANG_FAIL;
                }

                RawTarget rawTarget;
                rawTarget.format = CodeGenTarget(format);

                m_rawTargets.add(rawTarget);
                break;
            }
            case OptionKind::VulkanBindShift:
            {
                // -fvk-{b|s|t|u}-shift <binding-shift> <set>
                const auto slice = arg.value.getUnownedSlice().subString(5, 1);
                HLSLToVulkanLayoutOptions::Kind kind;
                SLANG_RETURN_ON_FAIL(_getValue(arg, slice, kind));

                Int shift;
                SLANG_RETURN_ON_FAIL(_expectInt(arg, shift));
                
                if (m_reader.hasArg() && m_reader.peekArg().value == toSlice("all"))
                {
                    m_reader.advance();
                    m_hlslToVulkanLayoutOptions->setAllShift(kind, shift);
                }
                else
                {
                    Int set;
                    SLANG_RETURN_ON_FAIL(_expectInt(arg, set));
                    m_hlslToVulkanLayoutOptions->setShift(kind, set, shift);
                }
                break;
            }
            case OptionKind::VulkanBindGlobals:
            {
                // -fvk-bind-globals <index> <set>
                Int binding, bindingSet;
                SLANG_RETURN_ON_FAIL(_expectInt(arg, binding));
                SLANG_RETURN_ON_FAIL(_expectInt(arg, bindingSet));

                m_hlslToVulkanLayoutOptions->setGlobalsBinding(Index(bindingSet), Index(binding));
                break;
            }
            case OptionKind::VulkanInvertY:
            {
                // -fvk-invert-y
                m_hlslToVulkanLayoutOptions->setInvertY(true);
                break;
            }
            case OptionKind::VulkanUseEntryPointName:
            {
                // -fvk-use-entrypoint-name
                m_hlslToVulkanLayoutOptions->setUseOriginalEntryPointName(true);
                break;
            }
            case OptionKind::VulkanUseGLLayout:
            {
                // -fvk-use-gl-layout
                m_hlslToVulkanLayoutOptions->setUseGLLayout(true);
                break;
            }
            case OptionKind::VulkanEmitReflection:
            {
                // -fvk-invert-y
                m_hlslToVulkanLayoutOptions->setEmitSPIRVReflectionInfo(true);
                break;
            }
            case OptionKind::Profile: SLANG_RETURN_ON_FAIL(_parseProfile(arg)); break;
            case OptionKind::Capability:
            {
                // The `-capability` option is similar to `-profile` but does not set the actual profile
                // for a target (it just adds capabilities).
                //
                // TODO: Once profiles are treated as capabilities themselves, it might be possible
                // to treat `-profile` and `-capability` as aliases, although there might still be
                // value in only allowing a single `-profile` option per target while still allowing
                // zero or more `-capability` options.

                CommandLineArg operand;
                SLANG_RETURN_ON_FAIL(m_reader.expectArg(operand));

                List<UnownedStringSlice> slices;
                StringUtil::split(operand.value.getUnownedSlice(), '+', slices);
                Index sliceCount = slices.getCount();
                for (Index i = 0; i < sliceCount; ++i)
                {
                    UnownedStringSlice atomName = slices[i];
                    CapabilityName atom = findCapabilityName(atomName);
                    if (atom == CapabilityName::Invalid)
                    {
                        m_sink->diagnose(operand.loc, Diagnostics::unknownProfile, atomName);
                        return SLANG_FAIL;
                    }

                    addCapabilityAtom(getCurrentTarget(), atom);
                }
                break;
            }
            case OptionKind::Stage:
            {
                CommandLineArg name;
                SLANG_RETURN_ON_FAIL(m_reader.expectArg(name));

                Stage stage = findStageByName(name.value);
                if (stage == Stage::Unknown)
                {
                    m_sink->diagnose(name.loc, Diagnostics::unknownStage, name.value);
                    return SLANG_FAIL;
                }
                else
                {
                    setStage(getCurrentEntryPoint(), stage);
                }
                break;
            }
            case OptionKind::GLSLForceScalarLayout:
            {
                getCurrentTarget()->forceGLSLScalarLayout = true;
                break;
            }
            case OptionKind::EnableEffectAnnotations:
            {
                m_compileRequest->setEnableEffectAnnotations(true);
                break;
            }

            case OptionKind::EntryPointName:
            {
                CommandLineArg name;
                SLANG_RETURN_ON_FAIL(m_reader.expectArg(name));

                RawEntryPoint rawEntryPoint;
                rawEntryPoint.name = name.value;
                rawEntryPoint.translationUnitIndex = m_currentTranslationUnitIndex;

                m_rawEntryPoints.add(rawEntryPoint);
                break;
            }
            case OptionKind::Language:
            {
                CommandLineArg name;
                SLANG_RETURN_ON_FAIL(m_reader.expectArg(name));

                const SourceLanguage sourceLanguage = (SourceLanguage)TypeTextUtil::findSourceLanguage(name.value.getUnownedSlice());

                if (sourceLanguage == SourceLanguage::Unknown)
                {
                    m_sink->diagnose(name.loc, Diagnostics::unknownSourceLanguage, name.value);
                    return SLANG_FAIL;
                }
                else
                {
                    while (m_reader.hasArg() && !m_reader.peekValue().startsWith("-"))
                    {
                        SLANG_RETURN_ON_FAIL(addInputPath(m_reader.getValueAndAdvance().getBuffer(), sourceLanguage));
                    }
                }
                break;
            }
            case OptionKind::PassThrough:
            {
                CommandLineArg name;
                SLANG_RETURN_ON_FAIL(m_reader.expectArg(name));

                SlangPassThrough passThrough = SLANG_PASS_THROUGH_NONE;
                if (SLANG_FAILED(TypeTextUtil::findPassThrough(name.value.getUnownedSlice(), passThrough)))
                {
                    m_sink->diagnose(name.loc, Diagnostics::unknownPassThroughTarget, name.value);
                    return SLANG_FAIL;
                }

                m_compileRequest->setPassThrough(passThrough);
                break;
            }
            case OptionKind::MacroDefine:
            {
                // The value to be defined might be part of the same option, as in:
                //     -DFOO
                // or it might come separately, as in:
                //     -D FOO

                UnownedStringSlice slice = argValue.getUnownedSlice().tail(2);

                CommandLineArg nextArg;
                if (slice.getLength() <= 0)
                {
                    SLANG_RETURN_ON_FAIL(m_reader.expectArg(nextArg));
                    slice = nextArg.value.getUnownedSlice();
                }

                // The string that sets up the define can have an `=` between
                // the name to be defined and its value, so we search for one.
                const Index equalIndex = slice.indexOf('=');

                // Now set the preprocessor define

                if (equalIndex >= 0)
                {
                    // If we found an `=`, we split the string...
                    m_compileRequest->addPreprocessorDefine(String(slice.head(equalIndex)).getBuffer(), String(slice.tail(equalIndex + 1)).getBuffer());
                }
                else
                {
                    // If there was no `=`, then just #define it to an empty string
                    m_compileRequest->addPreprocessorDefine(String(slice).getBuffer(), "");
                }
                break;
            }
            case OptionKind::Include:
            {
                // The value to be defined might be part of the same option, as in:
                //     -IFOO
                // or it might come separately, as in:
                //     -I FOO
                // (see handling of `-D` above)
                UnownedStringSlice slice = argValue.getUnownedSlice().tail(2);

                CommandLineArg nextArg;
                if (slice.getLength() <= 0)
                {
                    // Need to read another argument from the command line
                    SLANG_RETURN_ON_FAIL(m_reader.expectArg(nextArg));
                    slice = nextArg.value.getUnownedSlice();
                }

                m_compileRequest->addSearchPath(String(slice).getBuffer());
                break;
            }
            case OptionKind::Output:
            {
                //
                // A `-o` option is used to specify a desired output file.
                CommandLineArg outputPath;
                SLANG_RETURN_ON_FAIL(m_reader.expectArg(outputPath));

                addOutputPath(outputPath.value.getBuffer());
                break;
            }
            case OptionKind::DepFile:
            {
                CommandLineArg dependencyPath;
                SLANG_RETURN_ON_FAIL(m_reader.expectArg(dependencyPath));

                if (m_requestImpl->m_dependencyOutputPath.getLength() == 0)
                {
                    m_requestImpl->m_dependencyOutputPath = dependencyPath.value;
                }
                else
                {
                    m_sink->diagnose(dependencyPath.loc, Diagnostics::duplicateDependencyOutputPaths);
                    return SLANG_FAIL;
                }
                break;
            }
            case OptionKind::MatrixLayoutRow:       m_defaultMatrixLayoutMode = SlangMatrixLayoutMode(kMatrixLayoutMode_RowMajor); break;
            case OptionKind::MatrixLayoutColumn:    m_defaultMatrixLayoutMode = SlangMatrixLayoutMode(kMatrixLayoutMode_ColumnMajor); break;
            case OptionKind::LineDirectiveMode: 
            {
                SlangLineDirectiveMode value;
                SLANG_RETURN_ON_FAIL(_expectValue(value));
                m_compileRequest->setLineDirectiveMode(value);
                break;
            }
            case OptionKind::FloatingPointMode:
            {
                FloatingPointMode value;
                SLANG_RETURN_ON_FAIL(_expectValue(value));
                setFloatingPointMode(getCurrentTarget(), value);
                break;
            }
            case OptionKind::Optimization:
            {
                UnownedStringSlice levelSlice = argValue.getUnownedSlice().tail(2);
                SlangOptimizationLevel level = SLANG_OPTIMIZATION_LEVEL_DEFAULT;
            
                if (levelSlice.getLength())
                {
                    SLANG_RETURN_ON_FAIL(_getValue(arg, levelSlice, level));
                }

                m_compileRequest->setOptimizationLevel(level);
                break;
            }
            case OptionKind::DebugInformation: SLANG_RETURN_ON_FAIL(_parseDebugInformation(arg)); break;
            case OptionKind::DefaultImageFormatUnknown: m_requestImpl->useUnknownImageFormatAsDefault = true; break;
            case OptionKind::Obfuscate: m_requestImpl->getLinkage()->m_obfuscateCode = true; break;
            case OptionKind::FileSystem:
            {
                typedef TypeTextUtil::FileSystemType FileSystemType;
                FileSystemType value;
                SLANG_RETURN_ON_FAIL(_expectValue(value));
                
                switch (value)
                {
                    case FileSystemType::Default:   m_compileRequest->setFileSystem(nullptr); break;
                    case FileSystemType::LoadFile:  m_compileRequest->setFileSystem(OSFileSystem::getLoadSingleton()); break;
                    case FileSystemType::Os:        m_compileRequest->setFileSystem(OSFileSystem::getExtSingleton()); break;
                }
                break;
            }
            case OptionKind::ReferenceModule:   SLANG_RETURN_ON_FAIL(_parseReferenceModule(arg)); break;
            case OptionKind::Version:
            {
                m_sink->diagnoseRaw(Severity::Note, m_session->getBuildTagString());
                break;
            }
            case OptionKind::HelpStyle:     SLANG_RETURN_ON_FAIL(_expectValue(m_helpStyle)); break;
            case OptionKind::Help:
            {
                SLANG_RETURN_ON_FAIL(_parseHelp(arg));

                // We retun an error so after this has successfully passed, we quit
                return SLANG_FAIL;
            }
            case OptionKind::EmitSpirvViaGLSL:
            {
                getCurrentTarget()->targetFlags &= ~SLANG_TARGET_FLAG_GENERATE_SPIRV_DIRECTLY;
            }
            break;
            case OptionKind::EmitSpirvDirectly:
            {
                getCurrentTarget()->targetFlags |= SLANG_TARGET_FLAG_GENERATE_SPIRV_DIRECTLY;
            }
            break;
            case OptionKind::SPIRVCoreGrammarJSON:
            {
                CommandLineArg path;
                SLANG_RETURN_ON_FAIL(m_reader.expectArg(path));
                m_spirvCoreGrammarJSONPath = path.value;
            }
            break;

            case OptionKind::DefaultDownstreamCompiler:
            {
                CommandLineArg sourceLanguageArg, compilerArg;
                SLANG_RETURN_ON_FAIL(m_reader.expectArg(sourceLanguageArg));
                SLANG_RETURN_ON_FAIL(m_reader.expectArg(compilerArg));

                SlangSourceLanguage sourceLanguage = TypeTextUtil::findSourceLanguage(sourceLanguageArg.value.getUnownedSlice());
                if (sourceLanguage == SLANG_SOURCE_LANGUAGE_UNKNOWN)
                {
                    m_sink->diagnose(sourceLanguageArg.loc, Diagnostics::unknownSourceLanguage, sourceLanguageArg.value);
                    return SLANG_FAIL;
                }

                SlangPassThrough compiler;
                if (SLANG_FAILED(TypeTextUtil::findPassThrough(compilerArg.value.getUnownedSlice(), compiler)))
                {
                    m_sink->diagnose(compilerArg.loc, Diagnostics::unknownPassThroughTarget, compilerArg.value);
                    return SLANG_FAIL;
                }

                if (SLANG_FAILED(m_session->setDefaultDownstreamCompiler(sourceLanguage, compiler)))
                {
                    m_sink->diagnose(arg.loc, Diagnostics::unableToSetDefaultDownstreamCompiler, compilerArg.value, sourceLanguageArg.value);
                    return SLANG_FAIL;
                }
                break;
            }
            case OptionKind::CompilerPath:
            {
                const Index index = argValue.lastIndexOf('-');
                if (index >= 0)
                {
                    CommandLineArg name;
                    SLANG_RETURN_ON_FAIL(m_reader.expectArg(name));

                    UnownedStringSlice passThroughSlice = argValue.getUnownedSlice().head(index).tail(1);

                    // Skip the initial -, up to the last -
                    SlangPassThrough passThrough = SLANG_PASS_THROUGH_NONE;
                    if (SLANG_SUCCEEDED(TypeTextUtil::findPassThrough(passThroughSlice, passThrough)))
                    {
                        m_session->setDownstreamCompilerPath(passThrough, name.value.getBuffer());
                        continue;
                    }
                    else
                    {
                        m_sink->diagnose(arg.loc, Diagnostics::unknownDownstreamCompiler, passThroughSlice);
                        return SLANG_FAIL;
                    }
                }
                break;
            }
            case OptionKind::InputFilesRemain:
            {
                // The `--` option causes us to stop trying to parse options,
                // and treat the rest of the command line as input file names:
                while (m_reader.hasArg())
                {
                    SLANG_RETURN_ON_FAIL(addInputPath(m_reader.getValueAndAdvance().getBuffer()));
                }
                break;
            }
            case OptionKind::SourceEmbedStyle:
            {
                SLANG_RETURN_ON_FAIL(_expectValue(m_requestImpl->m_sourceEmbedStyle));
                break;
            }
            case OptionKind::SourceEmbedName:
            {
                CommandLineArg name;
                SLANG_RETURN_ON_FAIL(m_reader.expectArg(name));
                m_requestImpl->m_sourceEmbedName = name.value;
                break;
            }
            case OptionKind::SourceEmbedLanguage:
            {
                SLANG_RETURN_ON_FAIL(_expectValue(m_requestImpl->m_sourceEmbedLanguage));

                if (!SourceEmbedUtil::isSupported((SlangSourceLanguage)m_requestImpl->m_sourceEmbedLanguage))
                {
                    m_sink->diagnose(arg.loc, Diagnostics::unhandledLanguageForSourceEmbedding);
                    return SLANG_FAIL;
                }

                break;
            }
            default:
            {
                // Hmmm, we looked up and produced a valid enum, but it wasn't handled in the switch... 
                m_sink->diagnose(arg.loc, Diagnostics::unknownCommandLineOption, argValue);

                _outputMinimalUsage();
                return SLANG_FAIL;
            }
        }
    }

    // If there is state set on HLSL to Vulkan layout settings, set on the end to end request
    // such can be added when target requests are setup
    if (!m_hlslToVulkanLayoutOptions->isReset())
    {
        m_requestImpl->setHLSLToVulkanLayoutOptions(m_hlslToVulkanLayoutOptions);
    }

    // No longer need to track
    m_hlslToVulkanLayoutOptions.setNull();
    
    if (m_compileStdLib)
    {
        SLANG_RETURN_ON_FAIL(m_session->compileStdLib(m_compileStdLibFlags));
    }

    // TODO(JS): This is a restriction because of how setting of state works for load repro
    // If a repro has been loaded, then many of the following options will overwrite
    // what was set up. So for now they are ignored, and only parameters set as part
    // of the loop work if they are after -load-repro
    if (m_hasLoadedRepro)
    {
        return SLANG_OK;
    }

    m_compileRequest->setCompileFlags(m_flags);

    m_compileRequest->setAllowGLSLInput(m_allowGLSLInput);

    // As a compatability feature, if the user didn't list any explicit entry
    // point names, *and* they are compiling a single translation unit, *and* they
    // have either specified a stage, or we can assume one from the naming
    // of the translation unit, then we assume they wanted to compile a single
    // entry point named `main`.
    //
    if (m_rawEntryPoints.getCount() == 0
        && m_rawTranslationUnits.getCount() == 1
        && (m_defaultEntryPoint.stage != Stage::Unknown
            || m_rawTranslationUnits[0].impliedStage != Stage::Unknown))
    {
        RawEntryPoint entry;
        entry.name = "main";
        entry.translationUnitIndex = 0;
        m_rawEntryPoints.add(entry);
    }

    // If the user (manually or implicitly) specified only a single entry point,
    // then we allow the associated stage to be specified either before or after
    // the entry point. This means that if there is a stage attached
    // to the "default" entry point, we should copy it over to the
    // explicit one.
    //
    if (m_rawEntryPoints.getCount() == 1)
    {
        if (m_defaultEntryPoint.stage != Stage::Unknown)
        {
            setStage(getCurrentEntryPoint(), m_defaultEntryPoint.stage);
        }

        if (m_defaultEntryPoint.redundantStageSet)
            getCurrentEntryPoint()->redundantStageSet = true;
        if (m_defaultEntryPoint.conflictingStagesSet)
            getCurrentEntryPoint()->conflictingStagesSet = true;
    }
    else
    {
        // If the "default" entry point has had a stage (or
        // other state, if we add other per-entry-point state)
        // specified, but there is more than one entry point,
        // then that state doesn't apply to anything and we
        // should issue an error to tell the user something
        // funky is going on.
        //
        if (m_defaultEntryPoint.stage != Stage::Unknown)
        {
            if (m_rawEntryPoints.getCount() == 0)
            {
                m_sink->diagnose(SourceLoc(), Diagnostics::stageSpecificationIgnoredBecauseNoEntryPoints);
            }
            else
            {
                m_sink->diagnose(SourceLoc(), Diagnostics::stageSpecificationIgnoredBecauseBeforeAllEntryPoints);
            }
        }
    }

    // Slang requires that every explicit entry point indicate the translation
    // unit it comes from. If there is only one translation unit specified,
    // then implicitly all entry points come from it.
    //
    if (m_translationUnitCount == 1)
    {
        for (auto& entryPoint : m_rawEntryPoints)
        {
            entryPoint.translationUnitIndex = 0;
        }
    }
    else
    {
        // Otherwise, we require that all entry points be specified after
        // the translation unit to which tye belong.
        bool anyEntryPointWithoutTranslationUnit = false;
        for (auto& entryPoint : m_rawEntryPoints)
        {
            // Skip entry points that are already associated with a translation unit...
            if (entryPoint.translationUnitIndex != -1)
                continue;

            anyEntryPointWithoutTranslationUnit = true;
        }
        if (anyEntryPointWithoutTranslationUnit)
        {
            m_sink->diagnose(SourceLoc(), Diagnostics::entryPointsNeedToBeAssociatedWithTranslationUnits);
            return SLANG_FAIL;
        }
    }

    // Now that entry points are associated with translation units,
    // we can make one additional pass where if an entry point has
    // no specified stage, but the nameing of its translation unit
    // implies a stage, we will use that (a manual `-stage` annotation
    // will always win out in such a case).
    //
    for (auto& rawEntryPoint : m_rawEntryPoints)
    {
        // Skip entry points that already have a stage.
        if (rawEntryPoint.stage != Stage::Unknown)
            continue;

        // Sanity check: don't process entry points with no associated translation unit.
        if (rawEntryPoint.translationUnitIndex == -1)
            continue;

        auto impliedStage = m_rawTranslationUnits[rawEntryPoint.translationUnitIndex].impliedStage;
        if (impliedStage != Stage::Unknown)
            rawEntryPoint.stage = impliedStage;
    }

    // Note: it is possible that some entry points still won't have associated
    // stages at this point, but we don't want to error out here, because
    // those entry points might get stages later, as part of semantic checking,
    // if the corresponding function has a `[shader("...")]` attribute.

    // Now that we've tried to establish stages for entry points, we can
    // issue diagnostics for cases where stages were set redundantly or
    // in conflicting ways.
    //
    for (auto& rawEntryPoint : m_rawEntryPoints)
    {
        if (rawEntryPoint.conflictingStagesSet)
        {
            m_sink->diagnose(SourceLoc(), Diagnostics::conflictingStagesForEntryPoint, rawEntryPoint.name);
        }
        else if (rawEntryPoint.redundantStageSet)
        {
            m_sink->diagnose(SourceLoc(), Diagnostics::sameStageSpecifiedMoreThanOnce, rawEntryPoint.stage, rawEntryPoint.name);
        }
        else if (rawEntryPoint.translationUnitIndex != -1)
        {
            // As a quality-of-life feature, if the file name implies a particular
            // stage, but the user manually specified something different for
            // their entry point, give a warning in case they made a mistake.

            auto& rawTranslationUnit = m_rawTranslationUnits[rawEntryPoint.translationUnitIndex];
            if (rawTranslationUnit.impliedStage != Stage::Unknown
                && rawEntryPoint.stage != Stage::Unknown
                && rawTranslationUnit.impliedStage != rawEntryPoint.stage)
            {
                m_sink->diagnose(SourceLoc(), Diagnostics::explicitStageDoesntMatchImpliedStage, rawEntryPoint.name, rawEntryPoint.stage, rawTranslationUnit.impliedStage);
            }
        }
    }

    // If the user is requesting code generation via pass-through,
    // then any entry points they specify need to have a stage set,
    // because fxc/dxc/glslang don't have a facility for taking
    // a named entry point and pulling its stage from an attribute.
    //
    if (_passThroughRequiresStage(m_requestImpl->m_passThrough))
    {
        for (auto& rawEntryPoint : m_rawEntryPoints)
        {
            if (rawEntryPoint.stage == Stage::Unknown)
            {
                m_sink->diagnose(SourceLoc(), Diagnostics::noStageSpecifiedInPassThroughMode, rawEntryPoint.name);
            }
        }
    }

    // We now have inferred enough information to add the
    // entry points to our compile request.
    //
    for (auto& rawEntryPoint : m_rawEntryPoints)
    {
        if (rawEntryPoint.translationUnitIndex < 0)
            continue;

        auto translationUnitID = m_rawTranslationUnits[rawEntryPoint.translationUnitIndex].translationUnitID;

        int entryPointID = m_compileRequest->addEntryPoint(
            translationUnitID,
            rawEntryPoint.name.begin(),
            SlangStage(rawEntryPoint.stage));

        rawEntryPoint.entryPointID = entryPointID;
    }

    // We are going to build a mapping from target formats to the
    // target that handles that format.
    Dictionary<CodeGenTarget, int> mapFormatToTargetIndex;

    // If there was no explicit `-target` specified, then we will look
    // at the `-o` options to see what we can infer.
    //
    if (m_rawTargets.getCount() == 0)
    {
        // If there are no targets and no outputs
        if (m_rawOutputs.getCount() == 0)
        {
            // And we have a container for output, then enable emitting SlangIR module
            if (m_requestImpl->m_containerFormat != ContainerFormat::None)
            {
                m_requestImpl->m_emitIr = true;
            }
        }
        else
        {
            for (auto& rawOutput : m_rawOutputs)
            {
                // Some outputs don't imply a target format, and we shouldn't use those for inference.
                auto impliedFormat = rawOutput.impliedFormat;
                if (impliedFormat == CodeGenTarget::Unknown)
                    continue;

                int targetIndex = 0;
                if (!mapFormatToTargetIndex.tryGetValue(impliedFormat, targetIndex))
                {
                    targetIndex = (int)m_rawTargets.getCount();

                    RawTarget rawTarget;
                    rawTarget.format = impliedFormat;
                    m_rawTargets.add(rawTarget);

                    mapFormatToTargetIndex[impliedFormat] = targetIndex;
                }

                rawOutput.targetIndex = targetIndex;
            }
        }
    }
    else
    {
        // If there were explicit targets, then we will use those, but still
        // build up our mapping. We should object if the same target format
        // is specified more than once (just because of the ambiguities
        // it will create).
        //
        int targetCount = (int)m_rawTargets.getCount();
        for (int targetIndex = 0; targetIndex < targetCount; ++targetIndex)
        {
            auto format = m_rawTargets[targetIndex].format;

            if (mapFormatToTargetIndex.containsKey(format))
            {
                m_sink->diagnose(SourceLoc(), Diagnostics::duplicateTargets, format);
            }
            else
            {
                mapFormatToTargetIndex[format] = targetIndex;
            }
        }
    }

    // If we weren't able to infer any targets from output paths (perhaps
    // because there were no output paths), but there was a profile specified,
    // then we can try to infer a target from the profile.
    //
    if (m_rawTargets.getCount() == 0
        && m_defaultTarget.profileVersion != ProfileVersion::Unknown
        && !m_defaultTarget.conflictingProfilesSet)
    {
        // Let's see if the chosen profile allows us to infer
        // the code gen target format that the user probably meant.
        //
        CodeGenTarget inferredFormat = CodeGenTarget::Unknown;
        auto profileVersion = m_defaultTarget.profileVersion;
        switch (Profile(profileVersion).getFamily())
        {
            default:
                break;

                // For GLSL profile versions, we will assume SPIR-V
                // is the output format the user intended.
            case ProfileFamily::GLSL:
                inferredFormat = CodeGenTarget::SPIRV;
                break;

                // For DX profile versions, we will assume that the
                // user wants DXIL for Shader Model 6.0 and up,
                // and DXBC for all earlier versions.
                //
                // Note: There is overlap where both DXBC and DXIL
                // nominally support SM 5.1, but in general we
                // expect users to prefer to make a clean break
                // at SM 6.0. Anybody who cares about the overlap
                // cases should manually specify `-target dxil`.
                //
            case ProfileFamily::DX:
                if (profileVersion >= ProfileVersion::DX_6_0)
                {
                    inferredFormat = CodeGenTarget::DXIL;
                }
                else
                {
                    inferredFormat = CodeGenTarget::DXBytecode;
                }
                break;
        }

        if (inferredFormat != CodeGenTarget::Unknown)
        {
            RawTarget rawTarget;
            rawTarget.format = inferredFormat;
            m_rawTargets.add(rawTarget);
        }
    }

    // Similar to the case for entry points, if there is a single target,
    // then we allow some of its options to come from the "default"
    // target state.
    if (m_rawTargets.getCount() == 1)
    {
        if (m_defaultTarget.profileVersion != ProfileVersion::Unknown)
        {
            setProfileVersion(getCurrentTarget(), m_defaultTarget.profileVersion);
        }
        for (auto atom : m_defaultTarget.capabilityAtoms)
        {
            addCapabilityAtom(getCurrentTarget(), atom);
        }

        getCurrentTarget()->targetFlags |= m_defaultTarget.targetFlags;

        if (m_defaultTarget.floatingPointMode != FloatingPointMode::Default)
        {
            setFloatingPointMode(getCurrentTarget(), m_defaultTarget.floatingPointMode);
        }
    }
    else
    {
        // If the "default" target has had a profile (or other state)
        // specified, but there is != 1 taget, then that state doesn't
        // apply to anythign and we should give the user an error.
        //
        if (m_defaultTarget.profileVersion != ProfileVersion::Unknown)
        {
            if (m_rawTargets.getCount() == 0)
            {
                // This should only happen if there were multiple `-profile` options,
                // so we didn't try to infer a target, or if the `-profile` option
                // somehow didn't imply a target.
                //
                m_sink->diagnose(SourceLoc(), Diagnostics::profileSpecificationIgnoredBecauseNoTargets);
            }
            else
            {
                m_sink->diagnose(SourceLoc(), Diagnostics::profileSpecificationIgnoredBecauseBeforeAllTargets);
            }
        }

        if (m_defaultTarget.targetFlags != kDefaultTargetFlags)
        {
            if (m_rawTargets.getCount() == 0)
            {
                m_sink->diagnose(SourceLoc(), Diagnostics::targetFlagsIgnoredBecauseNoTargets);
            }
            else
            {
                m_sink->diagnose(SourceLoc(), Diagnostics::targetFlagsIgnoredBecauseBeforeAllTargets);
            }
        }

        if (m_defaultTarget.floatingPointMode != FloatingPointMode::Default)
        {
            if (m_rawTargets.getCount() == 0)
            {
                m_sink->diagnose(SourceLoc(), Diagnostics::targetFlagsIgnoredBecauseNoTargets);
            }
            else
            {
                m_sink->diagnose(SourceLoc(), Diagnostics::targetFlagsIgnoredBecauseBeforeAllTargets);
            }
        }

    }
    for (auto& rawTarget : m_rawTargets)
    {
        if (rawTarget.conflictingProfilesSet)
        {
            m_sink->diagnose(SourceLoc(), Diagnostics::conflictingProfilesSpecifiedForTarget, rawTarget.format);
        }
        else if (rawTarget.redundantProfileSet)
        {
            m_sink->diagnose(SourceLoc(), Diagnostics::sameProfileSpecifiedMoreThanOnce, rawTarget.profileVersion, rawTarget.format);
        }
    }

    // TODO: do we need to require that a target must have a profile specified,
    // or will we continue to allow the profile to be inferred from the target?

    // We now have enough information to go ahead and declare the targets
    // through the Slang API:
    //
    for (auto& rawTarget : m_rawTargets)
    {
        int targetID = m_compileRequest->addCodeGenTarget(SlangCompileTarget(rawTarget.format));
        rawTarget.targetID = targetID;

        if (rawTarget.profileVersion != ProfileVersion::Unknown)
        {
            m_compileRequest->setTargetProfile(targetID, SlangProfileID(Profile(rawTarget.profileVersion).raw));
        }
        for (auto atom : rawTarget.capabilityAtoms)
        {
            m_requestImpl->addTargetCapability(targetID, SlangCapabilityID(atom));
        }

        if (rawTarget.targetFlags)
        {
            m_compileRequest->setTargetFlags(targetID, rawTarget.targetFlags);
        }

        if (rawTarget.floatingPointMode != FloatingPointMode::Default)
        {
            m_compileRequest->setTargetFloatingPointMode(targetID, SlangFloatingPointMode(rawTarget.floatingPointMode));
        }

        if (rawTarget.forceGLSLScalarLayout)
        {
            m_compileRequest->setTargetForceGLSLScalarBufferLayout(targetID, true);
        }
    }

    if (m_defaultMatrixLayoutMode != SLANG_MATRIX_LAYOUT_MODE_UNKNOWN)
    {
        m_compileRequest->setMatrixLayoutMode(m_defaultMatrixLayoutMode);
    }

    if(m_spirvCoreGrammarJSONPath.getLength())
    {
        m_session->setSPIRVCoreGrammar(m_spirvCoreGrammarJSONPath.getBuffer());
    }

    // Next we need to sort out the output files specified with `-o`, and
    // figure out which entry point and/or target they apply to.
    //
    // If there is only a single entry point, then that is automatically
    // the entry point that should be associated with all outputs.
    //
    if (m_rawEntryPoints.getCount() == 1)
    {
        for (auto& rawOutput : m_rawOutputs)
        {
            rawOutput.entryPointIndex = 0;
        }
    }
    //
    // Similarly, if there is only one target, then all outputs must
    // implicitly appertain to that target.
    //
    if (m_rawTargets.getCount() == 1)
    {
        for (auto& rawOutput : m_rawOutputs)
        {
            rawOutput.targetIndex = 0;
        }
    }

    // If we don't have any raw outputs but do have a raw target,
    // add an empty' rawOutput for certain targets where the expected behavior is obvious.
    if (m_rawOutputs.getCount() == 0 &&
        m_rawTargets.getCount() == 1 &&
        (m_rawTargets[0].format == CodeGenTarget::HostCPPSource ||
            m_rawTargets[0].format == CodeGenTarget::PyTorchCppBinding ||
            m_rawTargets[0].format == CodeGenTarget::CUDASource ||
            m_rawTargets[0].format == CodeGenTarget::SPIRV ||
            m_rawTargets[0].format == CodeGenTarget::SPIRVAssembly ||
            ArtifactDescUtil::makeDescForCompileTarget(asExternal(m_rawTargets[0].format)).kind == ArtifactKind::HostCallable))
    {
        RawOutput rawOutput;
        rawOutput.impliedFormat = m_rawTargets[0].format;
        rawOutput.targetIndex = 0;
        m_rawOutputs.add(rawOutput);
    }

    // Consider the output files specified via `-o` and try to figure
    // out how to deal with them.
    //
    for (auto& rawOutput : m_rawOutputs)
    {
        // For now, most output formats need to be tightly bound to
        // both a target and an entry point.

        // If an output doesn't have a target associated with
        // it, then search for the target with the matching format.
        if (rawOutput.targetIndex == -1)
        {
            auto impliedFormat = rawOutput.impliedFormat;
            int targetIndex = -1;

            if (impliedFormat == CodeGenTarget::Unknown)
            {
                // If we hit this case, then it means that we need to pick the
                // target to assocaite with this output based on its implied
                // format, but the file path doesn't direclty imply a format
                // (it doesn't have a suffix like `.spv` that tells us what to write).
                //
                m_sink->diagnose(SourceLoc(), Diagnostics::cannotDeduceOutputFormatFromPath, rawOutput.path);
            }
            else if (mapFormatToTargetIndex.tryGetValue(rawOutput.impliedFormat, targetIndex))
            {
                rawOutput.targetIndex = targetIndex;
            }
            else
            {
                m_sink->diagnose(SourceLoc(), Diagnostics::cannotMatchOutputFileToTarget, rawOutput.path, rawOutput.impliedFormat);
            }
        }

        // We won't do any searching to match an output file
        // with an entry point, since the case of a single entry
        // point was handled above, and the user is expected to
        // follow the ordering rules when using multiple entry points.
        if (rawOutput.entryPointIndex == -1)
        {
            if (rawOutput.targetIndex != -1)
            {
                auto outputFormat = m_rawTargets[rawOutput.targetIndex].format;
                // Here we check whether the given output format supports multiple entry points
                // When we add targets with support for multiple entry points,
                // we should update this switch with those new formats
                switch (outputFormat)
                {
                    case CodeGenTarget::CPPSource:
                    case CodeGenTarget::PTX:
                    case CodeGenTarget::CUDASource:

                    case CodeGenTarget::HostHostCallable:
                    case CodeGenTarget::ShaderHostCallable:
                    case CodeGenTarget::HostExecutable:
                    case CodeGenTarget::ShaderSharedLibrary:
                    case CodeGenTarget::PyTorchCppBinding:
                    case CodeGenTarget::DXIL:
                        rawOutput.isWholeProgram = true;
                        break;
                    case CodeGenTarget::SPIRV:
                    case CodeGenTarget::SPIRVAssembly:
                        if (getCurrentTarget()->targetFlags & SLANG_TARGET_FLAG_GENERATE_SPIRV_DIRECTLY)
                        {
                            rawOutput.isWholeProgram = true;
                        }
                        break;
                    default:
                        m_sink->diagnose(SourceLoc(), Diagnostics::cannotMatchOutputFileToEntryPoint, rawOutput.path);
                        break;
                }
            }
        }
    }


    // Now that we've diagnosed the output paths, we can add them
    // to the compile request at the appropriate locations.
    //
    // We will consider the output files specified via `-o` and try to figure
    // out how to deal with them.
    //
    for (auto& rawOutput : m_rawOutputs)
    {
        if (rawOutput.targetIndex == -1) continue;
        auto targetID = m_rawTargets[rawOutput.targetIndex].targetID;
        auto target = m_requestImpl->getLinkage()->targets[targetID];
        RefPtr<EndToEndCompileRequest::TargetInfo> targetInfo;
        if (!m_requestImpl->m_targetInfos.tryGetValue(target, targetInfo))
        {
            targetInfo = new EndToEndCompileRequest::TargetInfo();
            m_requestImpl->m_targetInfos[target] = targetInfo;
        }

        if (rawOutput.isWholeProgram)
        {
            if (targetInfo->wholeTargetOutputPath != "")
            {
                m_sink->diagnose(SourceLoc(), Diagnostics::duplicateOutputPathsForTarget, target->getTarget());
            }
            else
            {
                target->addTargetFlags(SLANG_TARGET_FLAG_GENERATE_WHOLE_PROGRAM);
                targetInfo->wholeTargetOutputPath = rawOutput.path;
            }
        }
        else
        {
            if (rawOutput.entryPointIndex == -1) continue;

            Int entryPointID = m_rawEntryPoints[rawOutput.entryPointIndex].entryPointID;
            auto entryPointReq = m_requestImpl->getFrontEndReq()->getEntryPointReqs()[entryPointID];

            //String outputPath;
            if (targetInfo->entryPointOutputPaths.containsKey(entryPointID))
            {
                m_sink->diagnose(SourceLoc(), Diagnostics::duplicateOutputPathsForEntryPointAndTarget, entryPointReq->getName(), target->getTarget());
            }
            else
            {
                targetInfo->entryPointOutputPaths[entryPointID] = rawOutput.path;
            }
        }
    }

    return (m_sink->getErrorCount() == 0) ? SLANG_OK : SLANG_FAIL;
}

SlangResult OptionsParser::parse(
    SlangCompileRequest* compileRequest,
    int             argc,
    char const* const* argv)
{
    m_compileRequest = compileRequest;
 
    // Set up useful members
    m_requestImpl = asInternal(compileRequest);

    auto session = asInternal(m_requestImpl->getSession());

    m_session = session;
    m_frontEndReq = m_requestImpl->getFrontEndReq();

    m_hlslToVulkanLayoutOptions = new HLSLToVulkanLayoutOptions;

    m_cmdOptions = &session->m_commandOptions;

    DiagnosticSink* requestSink = m_requestImpl->getSink();

    m_cmdLineContext = m_requestImpl->getLinkage()->m_downstreamArgs.getContext();

    // Why create a new DiagnosticSink?
    // We *don't* want the lexer that comes as default (it's for Slang source!)
    // We may want to set flags that are different
    // We will need to use a new sourceManager that will just last for this parse and will map locs to
    // source lines.
    //
    // The *problem* is that we still need to communicate to the requestSink in some suitable way.
    //
    // 1) We could have some kind of scoping mechanism (and only one sink)
    // 2) We could have a 'parent' diagnostic sink, that if we set we route output too
    // 3) We use something like the ISlangWriter to always be the thing output too (this has problems because
    // some code assumes the diagnostics are accessible as a string)
    //
    // The solution used here is to have DiagnosticsSink have a 'parent' that also gets diagnostics reported to.

    m_parseSink.init(m_cmdLineContext->getSourceManager(), nullptr);
    {
        m_parseSink.setFlags(requestSink->getFlags());
        // Allow HumaneLoc - it won't display much for command line parsing - just (1):
        // Leaving allows for diagnostics to be compatible with other Slang diagnostic parsing.
        //parseSink.resetFlag(DiagnosticSink::Flag::HumaneLoc);
        m_parseSink.setFlag(DiagnosticSink::Flag::SourceLocationLine);
    }

    // All diagnostics will also be sent to requestSink
    m_parseSink.setParentSink(requestSink);
    m_sink = &m_parseSink;

    Result res = _parse(argc, argv);
    
    m_sink = nullptr;

    if (requestSink->getErrorCount() > 0)
    {
        // Put the errors in the diagnostic 
        m_requestImpl->m_diagnosticOutput = requestSink->outputBuffer.produceString();
    }

    return res;
}

SlangResult parseOptions(
    SlangCompileRequest*    inCompileRequest,
    int                     argc,
    char const* const*      argv)
{
    OptionsParser parser;
    return parser.parse(inCompileRequest, argc, argv);
}


} // namespace Slang