/*
 * Copyright 2015-2021 Arm Limited
 * SPDX-License-Identifier: Apache-2.0 OR MIT
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/*
 * At your option, you may choose to accept this material under either:
 *  1. The Apache License, Version 2.0, found at <http://www.apache.org/licenses/LICENSE-2.0>, or
 *  2. The MIT License, found at <http://opensource.org/licenses/MIT>.
 */

#ifndef SPIRV_CROSS_COMMON_HPP
#define SPIRV_CROSS_COMMON_HPP

#ifndef SPV_ENABLE_UTILITY_CODE
#define SPV_ENABLE_UTILITY_CODE
#endif
#include "spirv.hpp"

#include "spirv_cross_containers.hpp"
#include "spirv_cross_error_handling.hpp"
#include <functional>

// A bit crude, but allows projects which embed SPIRV-Cross statically to
// effectively hide all the symbols from other projects.
// There is a case where we have:
// - Project A links against SPIRV-Cross statically.
// - Project A links against Project B statically.
// - Project B links against SPIRV-Cross statically (might be a different version).
// This leads to a conflict with extremely bizarre results.
// By overriding the namespace in one of the project builds, we can work around this.
// If SPIRV-Cross is embedded in dynamic libraries,
// prefer using -fvisibility=hidden on GCC/Clang instead.
#ifdef SPIRV_CROSS_NAMESPACE_OVERRIDE
#define SPIRV_CROSS_NAMESPACE SPIRV_CROSS_NAMESPACE_OVERRIDE
#else
#define SPIRV_CROSS_NAMESPACE spirv_cross
#endif

namespace SPIRV_CROSS_NAMESPACE
{
namespace inner
{
template <typename T>
void join_helper(StringStream<> &stream, T &&t)
{
    stream << std::forward<T>(t);
}

template <typename T, typename... Ts>
void join_helper(StringStream<> &stream, T &&t, Ts &&... ts)
{
    stream << std::forward<T>(t);
    join_helper(stream, std::forward<Ts>(ts)...);
}
} // namespace inner

class Bitset
{
public:
    Bitset() = default;
    explicit inline Bitset(uint64_t lower_)
        : lower(lower_)
    {
    }

    inline bool get(uint32_t bit) const
    {
        if (bit < 64)
            return (lower & (1ull << bit)) != 0;
        else
            return higher.count(bit) != 0;
    }

    inline void set(uint32_t bit)
    {
        if (bit < 64)
            lower |= 1ull << bit;
        else
            higher.insert(bit);
    }

    inline void clear(uint32_t bit)
    {
        if (bit < 64)
            lower &= ~(1ull << bit);
        else
            higher.erase(bit);
    }

    inline uint64_t get_lower() const
    {
        return lower;
    }

    inline void reset()
    {
        lower = 0;
        higher.clear();
    }

    inline void merge_and(const Bitset &other)
    {
        lower &= other.lower;
        std::unordered_set<uint32_t> tmp_set;
        for (auto &v : higher)
            if (other.higher.count(v) != 0)
                tmp_set.insert(v);
        higher = std::move(tmp_set);
    }

    inline void merge_or(const Bitset &other)
    {
        lower |= other.lower;
        for (auto &v : other.higher)
            higher.insert(v);
    }

    inline bool operator==(const Bitset &other) const
    {
        if (lower != other.lower)
            return false;

        if (higher.size() != other.higher.size())
            return false;

        for (auto &v : higher)
            if (other.higher.count(v) == 0)
                return false;

        return true;
    }

    inline bool operator!=(const Bitset &other) const
    {
        return !(*this == other);
    }

    template <typename Op>
    void for_each_bit(const Op &op) const
    {
        // TODO: Add ctz-based iteration.
        for (uint32_t i = 0; i < 64; i++)
        {
            if (lower & (1ull << i))
                op(i);
        }

        if (higher.empty())
            return;

        // Need to enforce an order here for reproducible results,
        // but hitting this path should happen extremely rarely, so having this slow path is fine.
        SmallVector<uint32_t> bits;
        bits.reserve(higher.size());
        for (auto &v : higher)
            bits.push_back(v);
        std::sort(std::begin(bits), std::end(bits));

        for (auto &v : bits)
            op(v);
    }

    inline bool empty() const
    {
        return lower == 0 && higher.empty();
    }

private:
    // The most common bits to set are all lower than 64,
    // so optimize for this case. Bits spilling outside 64 go into a slower data structure.
    // In almost all cases, higher data structure will not be used.
    uint64_t lower = 0;
    std::unordered_set<uint32_t> higher;
};

// Helper template to avoid lots of nasty string temporary munging.
template <typename... Ts>
std::string join(Ts &&... ts)
{
    StringStream<> stream;
    inner::join_helper(stream, std::forward<Ts>(ts)...);
    return stream.str();
}

inline std::string merge(const SmallVector<std::string> &list, const char *between = ", ")
{
    StringStream<> stream;
    for (auto &elem : list)
    {
        stream << elem;
        if (&elem != &list.back())
            stream << between;
    }
    return stream.str();
}

// Make sure we don't accidentally call this with float or doubles with SFINAE.
// Have to use the radix-aware overload.
template <typename T, typename std::enable_if<!std::is_floating_point<T>::value, int>::type = 0>
inline std::string convert_to_string(const T &t)
{
    return std::to_string(t);
}

static inline std::string convert_to_string(int32_t value)
{
    // INT_MIN is ... special on some backends. If we use a decimal literal, and negate it, we
    // could accidentally promote the literal to long first, then negate.
    // To workaround it, emit int(0x80000000) instead.
    if (value == (std::numeric_limits<int32_t>::min)())
        return "int(0x80000000)";
    else
        return std::to_string(value);
}

static inline std::string convert_to_string(int64_t value, const std::string &int64_type, bool long_long_literal_suffix)
{
    // INT64_MIN is ... special on some backends.
    // If we use a decimal literal, and negate it, we might overflow the representable numbers.
    // To workaround it, emit int(0x80000000) instead.
    if (value == (std::numeric_limits<int64_t>::min)())
        return join(int64_type, "(0x8000000000000000u", (long_long_literal_suffix ? "ll" : "l"), ")");
    else
        return std::to_string(value) + (long_long_literal_suffix ? "ll" : "l");
}

// Allow implementations to set a convenient standard precision
#ifndef SPIRV_CROSS_FLT_FMT
#define SPIRV_CROSS_FLT_FMT "%.32g"
#endif

// Disable sprintf and strcat warnings.
// We cannot rely on snprintf and family existing because, ..., MSVC.
#if defined(__clang__) || defined(__GNUC__)
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
#elif defined(_MSC_VER)
#pragma warning(push)
#pragma warning(disable : 4996)
#endif

static inline void fixup_radix_point(char *str, char radix_point)
{
    // Setting locales is a very risky business in multi-threaded program,
    // so just fixup locales instead. We only need to care about the radix point.
    if (radix_point != '.')
    {
        while (*str != '\0')
        {
            if (*str == radix_point)
                *str = '.';
            str++;
        }
    }
}

inline std::string convert_to_string(float t, char locale_radix_point)
{
    // std::to_string for floating point values is broken.
    // Fallback to something more sane.
    char buf[64];
    sprintf(buf, SPIRV_CROSS_FLT_FMT, t);
    fixup_radix_point(buf, locale_radix_point);

    // Ensure that the literal is float.
    if (!strchr(buf, '.') && !strchr(buf, 'e'))
        strcat(buf, ".0");
    return buf;
}

inline std::string convert_to_string(double t, char locale_radix_point)
{
    // std::to_string for floating point values is broken.
    // Fallback to something more sane.
    char buf[64];
    sprintf(buf, SPIRV_CROSS_FLT_FMT, t);
    fixup_radix_point(buf, locale_radix_point);

    // Ensure that the literal is float.
    if (!strchr(buf, '.') && !strchr(buf, 'e'))
        strcat(buf, ".0");
    return buf;
}

#if defined(__clang__) || defined(__GNUC__)
#pragma GCC diagnostic pop
#elif defined(_MSC_VER)
#pragma warning(pop)
#endif

class FloatFormatter
{
public:
    virtual ~FloatFormatter() = default;
    virtual std::string format_float(float value) = 0;
    virtual std::string format_double(double value) = 0;
};

template <typename T>
struct ValueSaver
{
    explicit ValueSaver(T &current_)
        : current(current_)
        , saved(current_)
    {
    }

    void release()
    {
        current = saved;
    }

    ~ValueSaver()
    {
        release();
    }

    T &current;
    T saved;
};

struct Instruction
{
    uint16_t op = 0;
    uint16_t count = 0;
    // If offset is 0 (not a valid offset into the instruction stream),
    // we have an instruction stream which is embedded in the object.
    uint32_t offset = 0;
    uint32_t length = 0;

    inline bool is_embedded() const
    {
        return offset == 0;
    }
};

struct EmbeddedInstruction : Instruction
{
    SmallVector<uint32_t> ops;
};

enum Types
{
    TypeNone,
    TypeType,
    TypeVariable,
    TypeConstant,
    TypeFunction,
    TypeFunctionPrototype,
    TypeBlock,
    TypeExtension,
    TypeExpression,
    TypeConstantOp,
    TypeCombinedImageSampler,
    TypeAccessChain,
    TypeUndef,
    TypeString,
    TypeCount
};

template <Types type>
class TypedID;

template <>
class TypedID<TypeNone>
{
public:
    TypedID() = default;
    TypedID(uint32_t id_)
        : id(id_)
    {
    }

    template <Types U>
    TypedID(const TypedID<U> &other)
    {
        *this = other;
    }

    template <Types U>
    TypedID &operator=(const TypedID<U> &other)
    {
        id = uint32_t(other);
        return *this;
    }

    // Implicit conversion to u32 is desired here.
    // As long as we block implicit conversion between TypedID<A> and TypedID<B> we're good.
    operator uint32_t() const
    {
        return id;
    }

    template <Types U>
    operator TypedID<U>() const
    {
        return TypedID<U>(*this);
    }

private:
    uint32_t id = 0;
};

template <Types type>
class TypedID
{
public:
    TypedID() = default;
    TypedID(uint32_t id_)
        : id(id_)
    {
    }

    explicit TypedID(const TypedID<TypeNone> &other)
        : id(uint32_t(other))
    {
    }

    operator uint32_t() const
    {
        return id;
    }

private:
    uint32_t id = 0;
};

using VariableID = TypedID<TypeVariable>;
using TypeID = TypedID<TypeType>;
using ConstantID = TypedID<TypeConstant>;
using FunctionID = TypedID<TypeFunction>;
using BlockID = TypedID<TypeBlock>;
using ID = TypedID<TypeNone>;

// Helper for Variant interface.
struct IVariant
{
    virtual ~IVariant() = default;
    virtual IVariant *clone(ObjectPoolBase *pool) = 0;
    ID self = 0;

protected:
    IVariant() = default;
    IVariant(const IVariant&) = default;
    IVariant &operator=(const IVariant&) = default;
};

#define SPIRV_CROSS_DECLARE_CLONE(T)                                \
    IVariant *clone(ObjectPoolBase *pool) override                  \
    {                                                               \
        return static_cast<ObjectPool<T> *>(pool)->allocate(*this); \
    }

struct SPIRUndef : IVariant
{
    enum
    {
        type = TypeUndef
    };

    explicit SPIRUndef(TypeID basetype_)
        : basetype(basetype_)
    {
    }
    TypeID basetype;

    SPIRV_CROSS_DECLARE_CLONE(SPIRUndef)
};

struct SPIRString : IVariant
{
    enum
    {
        type = TypeString
    };

    explicit SPIRString(std::string str_)
        : str(std::move(str_))
    {
    }

    std::string str;

    SPIRV_CROSS_DECLARE_CLONE(SPIRString)
};

// This type is only used by backends which need to access the combined image and sampler IDs separately after
// the OpSampledImage opcode.
struct SPIRCombinedImageSampler : IVariant
{
    enum
    {
        type = TypeCombinedImageSampler
    };
    SPIRCombinedImageSampler(TypeID type_, VariableID image_, VariableID sampler_)
        : combined_type(type_)
        , image(image_)
        , sampler(sampler_)
    {
    }
    TypeID combined_type;
    VariableID image;
    VariableID sampler;

    SPIRV_CROSS_DECLARE_CLONE(SPIRCombinedImageSampler)
};

struct SPIRConstantOp : IVariant
{
    enum
    {
        type = TypeConstantOp
    };

    SPIRConstantOp(TypeID result_type, spv::Op op, const uint32_t *args, uint32_t length)
        : opcode(op)
        , basetype(result_type)
    {
        arguments.reserve(length);
        for (uint32_t i = 0; i < length; i++)
            arguments.push_back(args[i]);
    }

    spv::Op opcode;
    SmallVector<uint32_t> arguments;
    TypeID basetype;

    SPIRV_CROSS_DECLARE_CLONE(SPIRConstantOp)
};

struct SPIRType : IVariant
{
    enum
    {
        type = TypeType
    };

    spv::Op op = spv::Op::OpNop;
    explicit SPIRType(spv::Op op_) : op(op_) {}

    enum BaseType
    {
        Unknown,
        Void,
        Boolean,
        SByte,
        UByte,
        Short,
        UShort,
        Int,
        UInt,
        Int64,
        UInt64,
        AtomicCounter,
        Half,
        Float,
        Double,
        Struct,
        Image,
        SampledImage,
        Sampler,
        AccelerationStructure,
        RayQuery,

        // Keep internal types at the end.
        ControlPointArray,
        Interpolant,
        Char
    };

    // Scalar/vector/matrix support.
    BaseType basetype = Unknown;
    uint32_t width = 0;
    uint32_t vecsize = 1;
    uint32_t columns = 1;

    // Arrays, support array of arrays by having a vector of array sizes.
    SmallVector<uint32_t> array;

    // Array elements can be either specialization constants or specialization ops.
    // This array determines how to interpret the array size.
    // If an element is true, the element is a literal,
    // otherwise, it's an expression, which must be resolved on demand.
    // The actual size is not really known until runtime.
    SmallVector<bool> array_size_literal;

    // Pointers
    // Keep track of how many pointer layers we have.
    uint32_t pointer_depth = 0;
    bool pointer = false;
    bool forward_pointer = false;

    spv::StorageClass storage = spv::StorageClassGeneric;

    SmallVector<TypeID> member_types;

    // If member order has been rewritten to handle certain scenarios with Offset,
    // allow codegen to rewrite the index.
    SmallVector<uint32_t> member_type_index_redirection;

    struct ImageType
    {
        TypeID type;
        spv::Dim dim;
        bool depth;
        bool arrayed;
        bool ms;
        uint32_t sampled;
        spv::ImageFormat format;
        spv::AccessQualifier access;
    } image = {};

    // Structs can be declared multiple times if they are used as part of interface blocks.
    // We want to detect this so that we only emit the struct definition once.
    // Since we cannot rely on OpName to be equal, we need to figure out aliases.
    TypeID type_alias = 0;

    // Denotes the type which this type is based on.
    // Allows the backend to traverse how a complex type is built up during access chains.
    TypeID parent_type = 0;

    // Used in backends to avoid emitting members with conflicting names.
    std::unordered_set<std::string> member_name_cache;

    SPIRV_CROSS_DECLARE_CLONE(SPIRType)
};

struct SPIRExtension : IVariant
{
    enum
    {
        type = TypeExtension
    };

    enum Extension
    {
        Unsupported,
        GLSL,
        SPV_debug_info,
        SPV_AMD_shader_ballot,
        SPV_AMD_shader_explicit_vertex_parameter,
        SPV_AMD_shader_trinary_minmax,
        SPV_AMD_gcn_shader,
        NonSemanticDebugPrintf,
        NonSemanticShaderDebugInfo,
        NonSemanticGeneric
    };

    explicit SPIRExtension(Extension ext_)
        : ext(ext_)
    {
    }

    Extension ext;
    SPIRV_CROSS_DECLARE_CLONE(SPIRExtension)
};

// SPIREntryPoint is not a variant since its IDs are used to decorate OpFunction,
// so in order to avoid conflicts, we can't stick them in the ids array.
struct SPIREntryPoint
{
    SPIREntryPoint(FunctionID self_, spv::ExecutionModel execution_model, const std::string &entry_name)
        : self(self_)
        , name(entry_name)
        , orig_name(entry_name)
        , model(execution_model)
    {
    }
    SPIREntryPoint() = default;

    FunctionID self = 0;
    std::string name;
    std::string orig_name;
    SmallVector<VariableID> interface_variables;

    Bitset flags;
    struct WorkgroupSize
    {
        uint32_t x = 0, y = 0, z = 0;
        uint32_t id_x = 0, id_y = 0, id_z = 0;
        uint32_t constant = 0; // Workgroup size can be expressed as a constant/spec-constant instead.
    } workgroup_size;
    uint32_t invocations = 0;
    uint32_t output_vertices = 0;
    uint32_t output_primitives = 0;
    spv::ExecutionModel model = spv::ExecutionModelMax;
    bool geometry_passthrough = false;
};

struct SPIRExpression : IVariant
{
    enum
    {
        type = TypeExpression
    };

    // Only created by the backend target to avoid creating tons of temporaries.
    SPIRExpression(std::string expr, TypeID expression_type_, bool immutable_)
        : expression(std::move(expr))
        , expression_type(expression_type_)
        , immutable(immutable_)
    {
    }

    // If non-zero, prepend expression with to_expression(base_expression).
    // Used in amortizing multiple calls to to_expression()
    // where in certain cases that would quickly force a temporary when not needed.
    ID base_expression = 0;

    std::string expression;
    TypeID expression_type = 0;

    // If this expression is a forwarded load,
    // allow us to reference the original variable.
    ID loaded_from = 0;

    // If this expression will never change, we can avoid lots of temporaries
    // in high level source.
    // An expression being immutable can be speculative,
    // it is assumed that this is true almost always.
    bool immutable = false;

    // Before use, this expression must be transposed.
    // This is needed for targets which don't support row_major layouts.
    bool need_transpose = false;

    // Whether or not this is an access chain expression.
    bool access_chain = false;

    // Whether or not gl_MeshVerticesEXT[].gl_Position (as a whole or .y) is referenced
    bool access_meshlet_position_y = false;

    // A list of expressions which this expression depends on.
    SmallVector<ID> expression_dependencies;

    // By reading this expression, we implicitly read these expressions as well.
    // Used by access chain Store and Load since we read multiple expressions in this case.
    SmallVector<ID> implied_read_expressions;

    // The expression was emitted at a certain scope. Lets us track when an expression read means multiple reads.
    uint32_t emitted_loop_level = 0;

    SPIRV_CROSS_DECLARE_CLONE(SPIRExpression)
};

struct SPIRFunctionPrototype : IVariant
{
    enum
    {
        type = TypeFunctionPrototype
    };

    explicit SPIRFunctionPrototype(TypeID return_type_)
        : return_type(return_type_)
    {
    }

    TypeID return_type;
    SmallVector<uint32_t> parameter_types;

    SPIRV_CROSS_DECLARE_CLONE(SPIRFunctionPrototype)
};

struct SPIRBlock : IVariant
{
    enum
    {
        type = TypeBlock
    };

    enum Terminator
    {
        Unknown,
        Direct, // Emit next block directly without a particular condition.

        Select, // Block ends with an if/else block.
        MultiSelect, // Block ends with switch statement.

        Return, // Block ends with return.
        Unreachable, // Noop
        Kill, // Discard
        IgnoreIntersection, // Ray Tracing
        TerminateRay, // Ray Tracing
        EmitMeshTasks // Mesh shaders
    };

    enum Merge
    {
        MergeNone,
        MergeLoop,
        MergeSelection
    };

    enum Hints
    {
        HintNone,
        HintUnroll,
        HintDontUnroll,
        HintFlatten,
        HintDontFlatten
    };

    enum Method
    {
        MergeToSelectForLoop,
        MergeToDirectForLoop,
        MergeToSelectContinueForLoop
    };

    enum ContinueBlockType
    {
        ContinueNone,

        // Continue block is branchless and has at least one instruction.
        ForLoop,

        // Noop continue block.
        WhileLoop,

        // Continue block is conditional.
        DoWhileLoop,

        // Highly unlikely that anything will use this,
        // since it is really awkward/impossible to express in GLSL.
        ComplexLoop
    };

    enum : uint32_t
    {
        NoDominator = 0xffffffffu
    };

    Terminator terminator = Unknown;
    Merge merge = MergeNone;
    Hints hint = HintNone;
    BlockID next_block = 0;
    BlockID merge_block = 0;
    BlockID continue_block = 0;

    ID return_value = 0; // If 0, return nothing (void).
    ID condition = 0;
    BlockID true_block = 0;
    BlockID false_block = 0;
    BlockID default_block = 0;

    // If terminator is EmitMeshTasksEXT.
    struct
    {
        ID groups[3];
        ID payload;
    } mesh = {};

    SmallVector<Instruction> ops;

    struct Phi
    {
        ID local_variable; // flush local variable ...
        BlockID parent; // If we're in from_block and want to branch into this block ...
        VariableID function_variable; // to this function-global "phi" variable first.
    };

    // Before entering this block flush out local variables to magical "phi" variables.
    SmallVector<Phi> phi_variables;

    // Declare these temporaries before beginning the block.
    // Used for handling complex continue blocks which have side effects.
    SmallVector<std::pair<TypeID, ID>> declare_temporary;

    // Declare these temporaries, but only conditionally if this block turns out to be
    // a complex loop header.
    SmallVector<std::pair<TypeID, ID>> potential_declare_temporary;

    struct Case
    {
        uint64_t value;
        BlockID block;
    };
    SmallVector<Case> cases_32bit;
    SmallVector<Case> cases_64bit;

    // If we have tried to optimize code for this block but failed,
    // keep track of this.
    bool disable_block_optimization = false;

    // If the continue block is complex, fallback to "dumb" for loops.
    bool complex_continue = false;

    // Do we need a ladder variable to defer breaking out of a loop construct after a switch block?
    bool need_ladder_break = false;

    // If marked, we have explicitly handled Phi from this block, so skip any flushes related to that on a branch.
    // Used to handle an edge case with switch and case-label fallthrough where fall-through writes to Phi.
    BlockID ignore_phi_from_block = 0;

    // The dominating block which this block might be within.
    // Used in continue; blocks to determine if we really need to write continue.
    BlockID loop_dominator = 0;

    // All access to these variables are dominated by this block,
    // so before branching anywhere we need to make sure that we declare these variables.
    SmallVector<VariableID> dominated_variables;

    // These are variables which should be declared in a for loop header, if we
    // fail to use a classic for-loop,
    // we remove these variables, and fall back to regular variables outside the loop.
    SmallVector<VariableID> loop_variables;

    // Some expressions are control-flow dependent, i.e. any instruction which relies on derivatives or
    // sub-group-like operations.
    // Make sure that we only use these expressions in the original block.
    SmallVector<ID> invalidate_expressions;

    SPIRV_CROSS_DECLARE_CLONE(SPIRBlock)
};

struct SPIRFunction : IVariant
{
    enum
    {
        type = TypeFunction
    };

    SPIRFunction(TypeID return_type_, TypeID function_type_)
        : return_type(return_type_)
        , function_type(function_type_)
    {
    }

    struct Parameter
    {
        TypeID type;
        ID id;
        uint32_t read_count;
        uint32_t write_count;

        // Set to true if this parameter aliases a global variable,
        // used mostly in Metal where global variables
        // have to be passed down to functions as regular arguments.
        // However, for this kind of variable, we should not care about
        // read and write counts as access to the function arguments
        // is not local to the function in question.
        bool alias_global_variable;
    };

    // When calling a function, and we're remapping separate image samplers,
    // resolve these arguments into combined image samplers and pass them
    // as additional arguments in this order.
    // It gets more complicated as functions can pull in their own globals
    // and combine them with parameters,
    // so we need to distinguish if something is local parameter index
    // or a global ID.
    struct CombinedImageSamplerParameter
    {
        VariableID id;
        VariableID image_id;
        VariableID sampler_id;
        bool global_image;
        bool global_sampler;
        bool depth;
    };

    TypeID return_type;
    TypeID function_type;
    SmallVector<Parameter> arguments;

    // Can be used by backends to add magic arguments.
    // Currently used by combined image/sampler implementation.

    SmallVector<Parameter> shadow_arguments;
    SmallVector<VariableID> local_variables;
    BlockID entry_block = 0;
    SmallVector<BlockID> blocks;
    SmallVector<CombinedImageSamplerParameter> combined_parameters;

    struct EntryLine
    {
        uint32_t file_id = 0;
        uint32_t line_literal = 0;
    };
    EntryLine entry_line;

    void add_local_variable(VariableID id)
    {
        local_variables.push_back(id);
    }

    void add_parameter(TypeID parameter_type, ID id, bool alias_global_variable = false)
    {
        // Arguments are read-only until proven otherwise.
        arguments.push_back({ parameter_type, id, 0u, 0u, alias_global_variable });
    }

    // Hooks to be run when the function returns.
    // Mostly used for lowering internal data structures onto flattened structures.
    // Need to defer this, because they might rely on things which change during compilation.
    // Intentionally not a small vector, this one is rare, and std::function can be large.
    Vector<std::function<void()>> fixup_hooks_out;

    // Hooks to be run when the function begins.
    // Mostly used for populating internal data structures from flattened structures.
    // Need to defer this, because they might rely on things which change during compilation.
    // Intentionally not a small vector, this one is rare, and std::function can be large.
    Vector<std::function<void()>> fixup_hooks_in;

    // On function entry, make sure to copy a constant array into thread addr space to work around
    // the case where we are passing a constant array by value to a function on backends which do not
    // consider arrays value types.
    SmallVector<ID> constant_arrays_needed_on_stack;

    bool active = false;
    bool flush_undeclared = true;
    bool do_combined_parameters = true;

    SPIRV_CROSS_DECLARE_CLONE(SPIRFunction)
};

struct SPIRAccessChain : IVariant
{
    enum
    {
        type = TypeAccessChain
    };

    SPIRAccessChain(TypeID basetype_, spv::StorageClass storage_, std::string base_, std::string dynamic_index_,
                    int32_t static_index_)
        : basetype(basetype_)
        , storage(storage_)
        , base(std::move(base_))
        , dynamic_index(std::move(dynamic_index_))
        , static_index(static_index_)
    {
    }

    // The access chain represents an offset into a buffer.
    // Some backends need more complicated handling of access chains to be able to use buffers, like HLSL
    // which has no usable buffer type ala GLSL SSBOs.
    // StructuredBuffer is too limited, so our only option is to deal with ByteAddressBuffer which works with raw addresses.

    TypeID basetype;
    spv::StorageClass storage;
    std::string base;
    std::string dynamic_index;
    int32_t static_index;

    VariableID loaded_from = 0;
    uint32_t matrix_stride = 0;
    uint32_t array_stride = 0;
    bool row_major_matrix = false;
    bool immutable = false;

    // By reading this expression, we implicitly read these expressions as well.
    // Used by access chain Store and Load since we read multiple expressions in this case.
    SmallVector<ID> implied_read_expressions;

    SPIRV_CROSS_DECLARE_CLONE(SPIRAccessChain)
};

struct SPIRVariable : IVariant
{
    enum
    {
        type = TypeVariable
    };

    SPIRVariable() = default;
    SPIRVariable(TypeID basetype_, spv::StorageClass storage_, ID initializer_ = 0, VariableID basevariable_ = 0)
        : basetype(basetype_)
        , storage(storage_)
        , initializer(initializer_)
        , basevariable(basevariable_)
    {
    }

    TypeID basetype = 0;
    spv::StorageClass storage = spv::StorageClassGeneric;
    uint32_t decoration = 0;
    ID initializer = 0;
    VariableID basevariable = 0;

    SmallVector<uint32_t> dereference_chain;
    bool compat_builtin = false;

    // If a variable is shadowed, we only statically assign to it
    // and never actually emit a statement for it.
    // When we read the variable as an expression, just forward
    // shadowed_id as the expression.
    bool statically_assigned = false;
    ID static_expression = 0;

    // Temporaries which can remain forwarded as long as this variable is not modified.
    SmallVector<ID> dependees;

    bool deferred_declaration = false;
    bool phi_variable = false;

    // Used to deal with Phi variable flushes. See flush_phi().
    bool allocate_temporary_copy = false;

    bool remapped_variable = false;
    uint32_t remapped_components = 0;

    // The block which dominates all access to this variable.
    BlockID dominator = 0;
    // If true, this variable is a loop variable, when accessing the variable
    // outside a loop,
    // we should statically forward it.
    bool loop_variable = false;
    // Set to true while we're inside the for loop.
    bool loop_variable_enable = false;

    // Used to find global LUTs
    bool is_written_to = false;

    SPIRFunction::Parameter *parameter = nullptr;

    SPIRV_CROSS_DECLARE_CLONE(SPIRVariable)
};

struct SPIRConstant : IVariant
{
    enum
    {
        type = TypeConstant
    };

    union Constant
    {
        uint32_t u32;
        int32_t i32;
        float f32;

        uint64_t u64;
        int64_t i64;
        double f64;
    };

    struct ConstantVector
    {
        Constant r[4];
        // If != 0, this element is a specialization constant, and we should keep track of it as such.
        ID id[4];
        uint32_t vecsize = 1;

        ConstantVector()
        {
            memset(r, 0, sizeof(r));
        }
    };

    struct ConstantMatrix
    {
        ConstantVector c[4];
        // If != 0, this column is a specialization constant, and we should keep track of it as such.
        ID id[4];
        uint32_t columns = 1;
    };

    static inline float f16_to_f32(uint16_t u16_value)
    {
        // Based on the GLM implementation.
        int s = (u16_value >> 15) & 0x1;
        int e = (u16_value >> 10) & 0x1f;
        int m = (u16_value >> 0) & 0x3ff;

        union
        {
            float f32;
            uint32_t u32;
        } u;

        if (e == 0)
        {
            if (m == 0)
            {
                u.u32 = uint32_t(s) << 31;
                return u.f32;
            }
            else
            {
                while ((m & 0x400) == 0)
                {
                    m <<= 1;
                    e--;
                }

                e++;
                m &= ~0x400;
            }
        }
        else if (e == 31)
        {
            if (m == 0)
            {
                u.u32 = (uint32_t(s) << 31) | 0x7f800000u;
                return u.f32;
            }
            else
            {
                u.u32 = (uint32_t(s) << 31) | 0x7f800000u | (m << 13);
                return u.f32;
            }
        }

        e += 127 - 15;
        m <<= 13;
        u.u32 = (uint32_t(s) << 31) | (e << 23) | m;
        return u.f32;
    }

    inline uint32_t specialization_constant_id(uint32_t col, uint32_t row) const
    {
        return m.c[col].id[row];
    }

    inline uint32_t specialization_constant_id(uint32_t col) const
    {
        return m.id[col];
    }

    inline uint32_t scalar(uint32_t col = 0, uint32_t row = 0) const
    {
        return m.c[col].r[row].u32;
    }

    inline int16_t scalar_i16(uint32_t col = 0, uint32_t row = 0) const
    {
        return int16_t(m.c[col].r[row].u32 & 0xffffu);
    }

    inline uint16_t scalar_u16(uint32_t col = 0, uint32_t row = 0) const
    {
        return uint16_t(m.c[col].r[row].u32 & 0xffffu);
    }

    inline int8_t scalar_i8(uint32_t col = 0, uint32_t row = 0) const
    {
        return int8_t(m.c[col].r[row].u32 & 0xffu);
    }

    inline uint8_t scalar_u8(uint32_t col = 0, uint32_t row = 0) const
    {
        return uint8_t(m.c[col].r[row].u32 & 0xffu);
    }

    inline float scalar_f16(uint32_t col = 0, uint32_t row = 0) const
    {
        return f16_to_f32(scalar_u16(col, row));
    }

    inline float scalar_f32(uint32_t col = 0, uint32_t row = 0) const
    {
        return m.c[col].r[row].f32;
    }

    inline int32_t scalar_i32(uint32_t col = 0, uint32_t row = 0) const
    {
        return m.c[col].r[row].i32;
    }

    inline double scalar_f64(uint32_t col = 0, uint32_t row = 0) const
    {
        return m.c[col].r[row].f64;
    }

    inline int64_t scalar_i64(uint32_t col = 0, uint32_t row = 0) const
    {
        return m.c[col].r[row].i64;
    }

    inline uint64_t scalar_u64(uint32_t col = 0, uint32_t row = 0) const
    {
        return m.c[col].r[row].u64;
    }

    inline const ConstantVector &vector() const
    {
        return m.c[0];
    }

    inline uint32_t vector_size() const
    {
        return m.c[0].vecsize;
    }

    inline uint32_t columns() const
    {
        return m.columns;
    }

    inline void make_null(const SPIRType &constant_type_)
    {
        m = {};
        m.columns = constant_type_.columns;
        for (auto &c : m.c)
            c.vecsize = constant_type_.vecsize;
    }

    inline bool constant_is_null() const
    {
        if (specialization)
            return false;
        if (!subconstants.empty())
            return false;

        for (uint32_t col = 0; col < columns(); col++)
            for (uint32_t row = 0; row < vector_size(); row++)
                if (scalar_u64(col, row) != 0)
                    return false;

        return true;
    }

    explicit SPIRConstant(uint32_t constant_type_)
        : constant_type(constant_type_)
    {
    }

    SPIRConstant() = default;

    SPIRConstant(TypeID constant_type_, const uint32_t *elements, uint32_t num_elements, bool specialized)
        : constant_type(constant_type_)
        , specialization(specialized)
    {
        subconstants.reserve(num_elements);
        for (uint32_t i = 0; i < num_elements; i++)
            subconstants.push_back(elements[i]);
        specialization = specialized;
    }

    // Construct scalar (32-bit).
    SPIRConstant(TypeID constant_type_, uint32_t v0, bool specialized)
        : constant_type(constant_type_)
        , specialization(specialized)
    {
        m.c[0].r[0].u32 = v0;
        m.c[0].vecsize = 1;
        m.columns = 1;
    }

    // Construct scalar (64-bit).
    SPIRConstant(TypeID constant_type_, uint64_t v0, bool specialized)
        : constant_type(constant_type_)
        , specialization(specialized)
    {
        m.c[0].r[0].u64 = v0;
        m.c[0].vecsize = 1;
        m.columns = 1;
    }

    // Construct vectors and matrices.
    SPIRConstant(TypeID constant_type_, const SPIRConstant *const *vector_elements, uint32_t num_elements,
                 bool specialized)
        : constant_type(constant_type_)
        , specialization(specialized)
    {
        bool matrix = vector_elements[0]->m.c[0].vecsize > 1;

        if (matrix)
        {
            m.columns = num_elements;

            for (uint32_t i = 0; i < num_elements; i++)
            {
                m.c[i] = vector_elements[i]->m.c[0];
                if (vector_elements[i]->specialization)
                    m.id[i] = vector_elements[i]->self;
            }
        }
        else
        {
            m.c[0].vecsize = num_elements;
            m.columns = 1;

            for (uint32_t i = 0; i < num_elements; i++)
            {
                m.c[0].r[i] = vector_elements[i]->m.c[0].r[0];
                if (vector_elements[i]->specialization)
                    m.c[0].id[i] = vector_elements[i]->self;
            }
        }
    }

    TypeID constant_type = 0;
    ConstantMatrix m;

    // If this constant is a specialization constant (i.e. created with OpSpecConstant*).
    bool specialization = false;
    // If this constant is used as an array length which creates specialization restrictions on some backends.
    bool is_used_as_array_length = false;

    // If true, this is a LUT, and should always be declared in the outer scope.
    bool is_used_as_lut = false;

    // For composites which are constant arrays, etc.
    SmallVector<ConstantID> subconstants;

    // Non-Vulkan GLSL, HLSL and sometimes MSL emits defines for each specialization constant,
    // and uses them to initialize the constant. This allows the user
    // to still be able to specialize the value by supplying corresponding
    // preprocessor directives before compiling the shader.
    std::string specialization_constant_macro_name;

    SPIRV_CROSS_DECLARE_CLONE(SPIRConstant)
};

// Variants have a very specific allocation scheme.
struct ObjectPoolGroup
{
    std::unique_ptr<ObjectPoolBase> pools[TypeCount];
};

class Variant
{
public:
    explicit Variant(ObjectPoolGroup *group_)
        : group(group_)
    {
    }

    ~Variant()
    {
        if (holder)
            group->pools[type]->deallocate_opaque(holder);
    }

    // Marking custom move constructor as noexcept is important.
    Variant(Variant &&other) SPIRV_CROSS_NOEXCEPT
    {
        *this = std::move(other);
    }

    // We cannot copy from other variant without our own pool group.
    // Have to explicitly copy.
    Variant(const Variant &variant) = delete;

    // Marking custom move constructor as noexcept is important.
    Variant &operator=(Variant &&other) SPIRV_CROSS_NOEXCEPT
    {
        if (this != &other)
        {
            if (holder)
                group->pools[type]->deallocate_opaque(holder);
            holder = other.holder;
            group = other.group;
            type = other.type;
            allow_type_rewrite = other.allow_type_rewrite;

            other.holder = nullptr;
            other.type = TypeNone;
        }
        return *this;
    }

    // This copy/clone should only be called in the Compiler constructor.
    // If this is called inside ::compile(), we invalidate any references we took higher in the stack.
    // This should never happen.
    Variant &operator=(const Variant &other)
    {
//#define SPIRV_CROSS_COPY_CONSTRUCTOR_SANITIZE
#ifdef SPIRV_CROSS_COPY_CONSTRUCTOR_SANITIZE
        abort();
#endif
        if (this != &other)
        {
            if (holder)
                group->pools[type]->deallocate_opaque(holder);

            if (other.holder)
                holder = other.holder->clone(group->pools[other.type].get());
            else
                holder = nullptr;

            type = other.type;
            allow_type_rewrite = other.allow_type_rewrite;
        }
        return *this;
    }

    void set(IVariant *val, Types new_type)
    {
        if (holder)
            group->pools[type]->deallocate_opaque(holder);
        holder = nullptr;

        if (!allow_type_rewrite && type != TypeNone && type != new_type)
        {
            if (val)
                group->pools[new_type]->deallocate_opaque(val);
            SPIRV_CROSS_THROW("Overwriting a variant with new type.");
        }

        holder = val;
        type = new_type;
        allow_type_rewrite = false;
    }

    template <typename T, typename... Ts>
    T *allocate_and_set(Types new_type, Ts &&... ts)
    {
        T *val = static_cast<ObjectPool<T> &>(*group->pools[new_type]).allocate(std::forward<Ts>(ts)...);
        set(val, new_type);
        return val;
    }

    template <typename T>
    T &get()
    {
        if (!holder)
            SPIRV_CROSS_THROW("nullptr");
        if (static_cast<Types>(T::type) != type)
            SPIRV_CROSS_THROW("Bad cast");
        return *static_cast<T *>(holder);
    }

    template <typename T>
    const T &get() const
    {
        if (!holder)
            SPIRV_CROSS_THROW("nullptr");
        if (static_cast<Types>(T::type) != type)
            SPIRV_CROSS_THROW("Bad cast");
        return *static_cast<const T *>(holder);
    }

    Types get_type() const
    {
        return type;
    }

    ID get_id() const
    {
        return holder ? holder->self : ID(0);
    }

    bool empty() const
    {
        return !holder;
    }

    void reset()
    {
        if (holder)
            group->pools[type]->deallocate_opaque(holder);
        holder = nullptr;
        type = TypeNone;
    }

    void set_allow_type_rewrite()
    {
        allow_type_rewrite = true;
    }

private:
    ObjectPoolGroup *group = nullptr;
    IVariant *holder = nullptr;
    Types type = TypeNone;
    bool allow_type_rewrite = false;
};

template <typename T>
T &variant_get(Variant &var)
{
    return var.get<T>();
}

template <typename T>
const T &variant_get(const Variant &var)
{
    return var.get<T>();
}

template <typename T, typename... P>
T &variant_set(Variant &var, P &&... args)
{
    auto *ptr = var.allocate_and_set<T>(static_cast<Types>(T::type), std::forward<P>(args)...);
    return *ptr;
}

struct AccessChainMeta
{
    uint32_t storage_physical_type = 0;
    bool need_transpose = false;
    bool storage_is_packed = false;
    bool storage_is_invariant = false;
    bool flattened_struct = false;
    bool relaxed_precision = false;
    bool access_meshlet_position_y = false;
};

enum ExtendedDecorations
{
    // Marks if a buffer block is re-packed, i.e. member declaration might be subject to PhysicalTypeID remapping and padding.
    SPIRVCrossDecorationBufferBlockRepacked = 0,

    // A type in a buffer block might be declared with a different physical type than the logical type.
    // If this is not set, PhysicalTypeID == the SPIR-V type as declared.
    SPIRVCrossDecorationPhysicalTypeID,

    // Marks if the physical type is to be declared with tight packing rules, i.e. packed_floatN on MSL and friends.
    // If this is set, PhysicalTypeID might also be set. It can be set to same as logical type if all we're doing
    // is converting float3 to packed_float3 for example.
    // If this is marked on a struct, it means the struct itself must use only Packed types for all its members.
    SPIRVCrossDecorationPhysicalTypePacked,

    // The padding in bytes before declaring this struct member.
    // If used on a struct type, marks the target size of a struct.
    SPIRVCrossDecorationPaddingTarget,

    SPIRVCrossDecorationInterfaceMemberIndex,
    SPIRVCrossDecorationInterfaceOrigID,
    SPIRVCrossDecorationResourceIndexPrimary,
    // Used for decorations like resource indices for samplers when part of combined image samplers.
    // A variable might need to hold two resource indices in this case.
    SPIRVCrossDecorationResourceIndexSecondary,
    // Used for resource indices for multiplanar images when part of combined image samplers.
    SPIRVCrossDecorationResourceIndexTertiary,
    SPIRVCrossDecorationResourceIndexQuaternary,

    // Marks a buffer block for using explicit offsets (GLSL/HLSL).
    SPIRVCrossDecorationExplicitOffset,

    // Apply to a variable in the Input storage class; marks it as holding the base group passed to vkCmdDispatchBase(),
    // or the base vertex and instance indices passed to vkCmdDrawIndexed().
    // In MSL, this is used to adjust the WorkgroupId and GlobalInvocationId variables in compute shaders,
    // and to hold the BaseVertex and BaseInstance variables in vertex shaders.
    SPIRVCrossDecorationBuiltInDispatchBase,

    // Apply to a variable that is a function parameter; marks it as being a "dynamic"
    // combined image-sampler. In MSL, this is used when a function parameter might hold
    // either a regular combined image-sampler or one that has an attached sampler
    // Y'CbCr conversion.
    SPIRVCrossDecorationDynamicImageSampler,

    // Apply to a variable in the Input storage class; marks it as holding the size of the stage
    // input grid.
    // In MSL, this is used to hold the vertex and instance counts in a tessellation pipeline
    // vertex shader.
    SPIRVCrossDecorationBuiltInStageInputSize,

    // Apply to any access chain of a tessellation I/O variable; stores the type of the sub-object
    // that was chained to, as recorded in the input variable itself. This is used in case the pointer
    // is itself used as the base of an access chain, to calculate the original type of the sub-object
    // chained to, in case a swizzle needs to be applied. This should not happen normally with valid
    // SPIR-V, but the MSL backend can change the type of input variables, necessitating the
    // addition of swizzles to keep the generated code compiling.
    SPIRVCrossDecorationTessIOOriginalInputTypeID,

    // Apply to any access chain of an interface variable used with pull-model interpolation, where the variable is a
    // vector but the resulting pointer is a scalar; stores the component index that is to be accessed by the chain.
    // This is used when emitting calls to interpolation functions on the chain in MSL: in this case, the component
    // must be applied to the result, since pull-model interpolants in MSL cannot be swizzled directly, but the
    // results of interpolation can.
    SPIRVCrossDecorationInterpolantComponentExpr,

    // Apply to any struct type that is used in the Workgroup storage class.
    // This causes matrices in MSL prior to Metal 3.0 to be emitted using a special
    // class that is convertible to the standard matrix type, to work around the
    // lack of constructors in the 'threadgroup' address space.
    SPIRVCrossDecorationWorkgroupStruct,

    SPIRVCrossDecorationOverlappingBinding,

    SPIRVCrossDecorationCount
};

struct Meta
{
    struct Decoration
    {
        std::string alias;
        std::string qualified_alias;
        std::string hlsl_semantic;
        std::string user_type;
        Bitset decoration_flags;
        spv::BuiltIn builtin_type = spv::BuiltInMax;
        uint32_t location = 0;
        uint32_t component = 0;
        uint32_t set = 0;
        uint32_t binding = 0;
        uint32_t offset = 0;
        uint32_t xfb_buffer = 0;
        uint32_t xfb_stride = 0;
        uint32_t stream = 0;
        uint32_t array_stride = 0;
        uint32_t matrix_stride = 0;
        uint32_t input_attachment = 0;
        uint32_t spec_id = 0;
        uint32_t index = 0;
        spv::FPRoundingMode fp_rounding_mode = spv::FPRoundingModeMax;
        bool builtin = false;
        bool qualified_alias_explicit_override = false;

        struct Extended
        {
            Extended()
            {
                // MSVC 2013 workaround to init like this.
                for (auto &v : values)
                    v = 0;
            }

            Bitset flags;
            uint32_t values[SPIRVCrossDecorationCount];
        } extended;
    };

    Decoration decoration;

    // Intentionally not a SmallVector. Decoration is large and somewhat rare.
    Vector<Decoration> members;

    std::unordered_map<uint32_t, uint32_t> decoration_word_offset;

    // For SPV_GOOGLE_hlsl_functionality1.
    bool hlsl_is_magic_counter_buffer = false;
    // ID for the sibling counter buffer.
    uint32_t hlsl_magic_counter_buffer = 0;
};

// A user callback that remaps the type of any variable.
// var_name is the declared name of the variable.
// name_of_type is the textual name of the type which will be used in the code unless written to by the callback.
using VariableTypeRemapCallback =
    std::function<void(const SPIRType &type, const std::string &var_name, std::string &name_of_type)>;

class Hasher
{
public:
    inline void u32(uint32_t value)
    {
        h = (h * 0x100000001b3ull) ^ value;
    }

    inline uint64_t get() const
    {
        return h;
    }

private:
    uint64_t h = 0xcbf29ce484222325ull;
};

static inline bool type_is_floating_point(const SPIRType &type)
{
    return type.basetype == SPIRType::Half || type.basetype == SPIRType::Float || type.basetype == SPIRType::Double;
}

static inline bool type_is_integral(const SPIRType &type)
{
    return type.basetype == SPIRType::SByte || type.basetype == SPIRType::UByte || type.basetype == SPIRType::Short ||
           type.basetype == SPIRType::UShort || type.basetype == SPIRType::Int || type.basetype == SPIRType::UInt ||
           type.basetype == SPIRType::Int64 || type.basetype == SPIRType::UInt64;
}

static inline SPIRType::BaseType to_signed_basetype(uint32_t width)
{
    switch (width)
    {
    case 8:
        return SPIRType::SByte;
    case 16:
        return SPIRType::Short;
    case 32:
        return SPIRType::Int;
    case 64:
        return SPIRType::Int64;
    default:
        SPIRV_CROSS_THROW("Invalid bit width.");
    }
}

static inline SPIRType::BaseType to_unsigned_basetype(uint32_t width)
{
    switch (width)
    {
    case 8:
        return SPIRType::UByte;
    case 16:
        return SPIRType::UShort;
    case 32:
        return SPIRType::UInt;
    case 64:
        return SPIRType::UInt64;
    default:
        SPIRV_CROSS_THROW("Invalid bit width.");
    }
}

// Returns true if an arithmetic operation does not change behavior depending on signedness.
static inline bool opcode_is_sign_invariant(spv::Op opcode)
{
    switch (opcode)
    {
    case spv::OpIEqual:
    case spv::OpINotEqual:
    case spv::OpISub:
    case spv::OpIAdd:
    case spv::OpIMul:
    case spv::OpShiftLeftLogical:
    case spv::OpBitwiseOr:
    case spv::OpBitwiseXor:
    case spv::OpBitwiseAnd:
        return true;

    default:
        return false;
    }
}

static inline bool opcode_can_promote_integer_implicitly(spv::Op opcode)
{
    switch (opcode)
    {
    case spv::OpSNegate:
    case spv::OpNot:
    case spv::OpBitwiseAnd:
    case spv::OpBitwiseOr:
    case spv::OpBitwiseXor:
    case spv::OpShiftLeftLogical:
    case spv::OpShiftRightLogical:
    case spv::OpShiftRightArithmetic:
    case spv::OpIAdd:
    case spv::OpISub:
    case spv::OpIMul:
    case spv::OpSDiv:
    case spv::OpUDiv:
    case spv::OpSRem:
    case spv::OpUMod:
    case spv::OpSMod:
        return true;

    default:
        return false;
    }
}

struct SetBindingPair
{
    uint32_t desc_set;
    uint32_t binding;

    inline bool operator==(const SetBindingPair &other) const
    {
        return desc_set == other.desc_set && binding == other.binding;
    }

    inline bool operator<(const SetBindingPair &other) const
    {
        return desc_set < other.desc_set || (desc_set == other.desc_set && binding < other.binding);
    }
};

struct LocationComponentPair
{
    uint32_t location;
    uint32_t component;

    inline bool operator==(const LocationComponentPair &other) const
    {
        return location == other.location && component == other.component;
    }

    inline bool operator<(const LocationComponentPair &other) const
    {
        return location < other.location || (location == other.location && component < other.component);
    }
};

struct StageSetBinding
{
    spv::ExecutionModel model;
    uint32_t desc_set;
    uint32_t binding;

    inline bool operator==(const StageSetBinding &other) const
    {
        return model == other.model && desc_set == other.desc_set && binding == other.binding;
    }
};

struct InternalHasher
{
    inline size_t operator()(const SetBindingPair &value) const
    {
        // Quality of hash doesn't really matter here.
        auto hash_set = std::hash<uint32_t>()(value.desc_set);
        auto hash_binding = std::hash<uint32_t>()(value.binding);
        return (hash_set * 0x10001b31) ^ hash_binding;
    }

    inline size_t operator()(const LocationComponentPair &value) const
    {
        // Quality of hash doesn't really matter here.
        auto hash_set = std::hash<uint32_t>()(value.location);
        auto hash_binding = std::hash<uint32_t>()(value.component);
        return (hash_set * 0x10001b31) ^ hash_binding;
    }

    inline size_t operator()(const StageSetBinding &value) const
    {
        // Quality of hash doesn't really matter here.
        auto hash_model = std::hash<uint32_t>()(value.model);
        auto hash_set = std::hash<uint32_t>()(value.desc_set);
        auto tmp_hash = (hash_model * 0x10001b31) ^ hash_set;
        return (tmp_hash * 0x10001b31) ^ value.binding;
    }
};

// Special constant used in a {MSL,HLSL}ResourceBinding desc_set
// element to indicate the bindings for the push constants.
static const uint32_t ResourceBindingPushConstantDescriptorSet = ~(0u);

// Special constant used in a {MSL,HLSL}ResourceBinding binding
// element to indicate the bindings for the push constants.
static const uint32_t ResourceBindingPushConstantBinding = 0;
} // namespace SPIRV_CROSS_NAMESPACE

namespace std
{
template <SPIRV_CROSS_NAMESPACE::Types type>
struct hash<SPIRV_CROSS_NAMESPACE::TypedID<type>>
{
    size_t operator()(const SPIRV_CROSS_NAMESPACE::TypedID<type> &value) const
    {
        return std::hash<uint32_t>()(value);
    }
};
} // namespace std

#endif