/*
 * Copyright (C) 2023-2024 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#pragma once

#if ENABLE(WEBASSEMBLY)

#include <JavaScriptCore/WasmCallingConvention.h>
#include <wtf/Expected.h>
#include <wtf/text/WTFString.h>

namespace JSC { namespace Wasm {

class FunctionIPIntMetadataGenerator;
class TypeDefinition;
struct ModuleInformation;
struct FunctionDebugInfo;

Expected<std::unique_ptr<FunctionIPIntMetadataGenerator>, String> parseAndCompileMetadata(std::span<const uint8_t>, const TypeDefinition&, ModuleInformation&, FunctionCodeIndex functionIndex);
void parseForDebugInfo(std::span<const uint8_t>, const TypeDefinition&, ModuleInformation&, FunctionCodeIndex, FunctionDebugInfo&);

} // namespace JSC::Wasm

namespace IPInt {

constexpr static unsigned STACK_ENTRY_SIZE = 16; // bytes
struct IPIntStackEntry {
    union {
        int32_t i32;
        float f32;
        int64_t i64;
        double f64;
        v128_t v128;
        EncodedJSValue ref;
    };
};

constexpr static unsigned LOCAL_SIZE = 16; // bytes
struct IPIntLocal {
    union {
        int32_t i32;
        float f32;
        int64_t i64;
        double f64;
        v128_t v128;
        EncodedJSValue ref;
    };
};

static_assert(sizeof(IPIntStackEntry) == STACK_ENTRY_SIZE);
static_assert(sizeof(IPIntLocal) == LOCAL_SIZE);

#pragma pack(1)

// Metadata structure for control flow instructions

struct InstructionLengthMetadata {
    uint8_t length; // 1B for length of current instruction
};

struct BlockMetadata {
    // Field order is significant, both may be loaded with one 'loadpairi' instruction.
    // Negative deltas are possible for some Wasm instructions and require sign extension to 64b before the addition.
    int32_t deltaPC; // 4B added to PC
    int32_t deltaMC; // 4B added to MC
};

struct IfMetadata {
    // Field order is significant, both may be loaded with one 'loadpairi' instruction.
    uint32_t elseDeltaPC; // 4B added to PC
    uint32_t elseDeltaMC; // 4B added to MC
    InstructionLengthMetadata instructionLength;
};

struct ThrowMetadata {
    uint32_t exceptionIndex; // 4B for exception index
};

struct RethrowMetadata {
    uint32_t tryDepth; // 4B for try depth
};

struct CatchMetadata {
    uint32_t stackSizeInV128; // 4B for stack size
};

struct BranchTargetMetadata {
    BlockMetadata block; // 8B for target
    uint16_t toPop; // 2B for stack values to pop
    uint16_t toKeep; // 2B for stack values to keep
};

struct BranchMetadata {
    BranchTargetMetadata target;
    InstructionLengthMetadata instructionLength;
};

struct SwitchMetadata {
    uint32_t size; // 4B for number of jump targets
    BranchTargetMetadata target[0];
};

// Global get/set metadata structure

struct GlobalMetadata {
    uint32_t index; // 4B for index of global
    InstructionLengthMetadata instructionLength;
    uint8_t bindingMode; // 1B for bindingMode
    uint8_t isRef; // 1B for ref flag
};

// Constant metadata structures

struct Const32Metadata {
    // instructionLength needs to go first because we encode small
    // i32 as just instructionLength with the value embedded in bytecode.
    InstructionLengthMetadata instructionLength;
    uint32_t value;
};

struct Const64Metadata {
    uint64_t value;
    InstructionLengthMetadata instructionLength;
};

struct Const128Metadata {
    v128_t value;
    InstructionLengthMetadata instructionLength;
};

struct TableInitMetadata {
    uint32_t elementIndex; // 4B for index of element
    uint32_t tableIndex; // 4B for index of table
    InstructionLengthMetadata instructionLength;
};

struct TableFillMetadata {
    uint32_t tableIndex; // 4B for index of table
    InstructionLengthMetadata instructionLength;
};

struct TableGrowMetadata {
    uint32_t tableIndex; // 4B for index of table
    InstructionLengthMetadata instructionLength;
};

struct TableCopyMetadata {
    uint32_t dstTableIndex; // 4B for index of destination table
    uint32_t srcTableIndex; // 4B for index of source table
    InstructionLengthMetadata instructionLength;
};

// Metadata structure for calls:

struct CallSignatureMetadata {
    uint32_t stackFrameSize; // 4B for stack frame size
    uint16_t numExtraResults; // 2B for number of spots we need to reserve for returns
    uint16_t numArguments; // 2B for number of arguments, to figure out how much to move SP down by
};

enum class CallArgumentBytecode : uint8_t { // (mINT)
    ArgumentGPR = 0x0, // 0x00 - 0x07: push into a0, a1, ...
    ArgumentFPR = 0x8, // 0x08 - 0x0f: push into fa0, fa1, ...

    // Note: addCallArgumentBytecode() requires that the corresponding CallArg and TailCallArg bytecodes
    // have a constant offset from each other

    // For Call, SP is actually a shadow stack, not the machine SP
    CallArgDecSP = 0x10, // Decrement SP by 16
    CallArgStore0 = 0x11, // Store 8-bytes to [SP]
    CallArgDecSPStore8 = 0x12, // Decrement SP by 16 and store 8-bytes to 8[SP]
    CallArgDecSPStoreVector0 = 0x13, // Decrement SP by 16 and store 16-bytes to [SP]
    CallArgDecSPStoreVector8 = 0x14, // Decrement SP by 16 and store 16-bytes to 8[SP]

    // Equivalent to the Call bytecodes above, but operates on machine SP directly
    TailCallArgDecSP = 0x15,
    TailCallArgStore0 = 0x16,
    TailCallArgDecSPStore8 = 0x17,
    TailCallArgDecSPStoreVector0 = 0x18,
    TailCallArgDecSPStoreVector8 = 0x19,

    TailCall = 0x1a,
    Call = 0x1b,

    NumOpcodes // this must be the last element of the enum!
};

struct CallMetadata {
    uint8_t length; // 1B for instruction length
    uint32_t callProfileIndex; // 4B for call profile index
    Wasm::FunctionSpaceIndex functionIndex; // 4B for decoded index
    CallSignatureMetadata signature;
    CallArgumentBytecode argumentBytecode[0];
};

struct TailCallMetadata {
    uint8_t length; // 1B for instruction length
    uint32_t callProfileIndex; // 4B for call profile index
    Wasm::FunctionSpaceIndex functionIndex; // 4B for decoded index
    int32_t callerStackArgSize; // 4B for caller stack size
    CallArgumentBytecode argumentBytecode[0];
};

struct CallIndirectMetadata {
    uint8_t length; // 1B for length
    uint32_t callProfileIndex; // 4B for call profile index
    uint32_t tableIndex; // 4B for table index
    SUPPRESS_UNCOUNTED_MEMBER const Wasm::RTT* rtt; // 8B for RTT
    CallSignatureMetadata signature;
    CallArgumentBytecode argumentBytecode[0];
};

struct TailCallIndirectMetadata {
    uint8_t length; // 1B for instruction length
    uint32_t callProfileIndex; // 4B for call profile index
    uint32_t tableIndex; // 4B for table index
    SUPPRESS_UNCOUNTED_MEMBER const Wasm::RTT* rtt; // 8B for RTT
    int32_t callerStackArgSize; // 4B for caller stack size
    CallArgumentBytecode argumentBytecode[0];
};

struct CallRefMetadata {
    uint8_t length; // 1B for length
    uint32_t callProfileIndex; // 4B for call profile index
    CallSignatureMetadata signature;
    CallArgumentBytecode argumentBytecode[0];
};

struct TailCallRefMetadata {
    uint8_t length; // 1B for length
    uint32_t callProfileIndex; // 4B for call profile index
    int32_t callerStackArgSize; // 4B for caller stack size
    CallArgumentBytecode argumentBytecode[0];
};

// Metadata structure for returns:

enum class CallResultBytecode : uint8_t { // (mINT)
    ResultGPR = 0x0, // 0x00 - 0x07: r0 - r7
    ResultFPR = 0x8, // 0x08 - 0x0f: fr0 - fr7
    ResultStack = 0x10,
    ResultStackVector = 0x11,
    End = 0x12,

    NumOpcodes // this must be the last element of the enum!
};

struct CallReturnMetadata {
    uint32_t stackFrameSize; // 4B for stack frame size
    uint32_t firstStackResultSPOffset; // 4B for stack argument offset
    CallResultBytecode resultBytecode[0];
};

// argumINT / uINT

enum class ArgumINTBytecode: uint8_t {
    ArgGPR = 0x0, // 0x00 - 0x07: r0 - r7
    ArgFPR = 0x8, // 0x08 - 0x0f: fr0 - fr7
    Stack = 0x10,
    StackVector = 0x11,
    End = 0x12,

    NumOpcodes // this must be the last element of the enum!
};

enum class UIntBytecode: uint8_t {
    RetGPR = 0x0, // 0x00 - 0x07: r0 - r7
    RetFPR = 0x8, // 0x08 - 0x0f: fr0 - fr7
    Stack = 0x10,
    StackVector = 0x11,
    End = 0x12,

    NumOpcodes // this must be the last element of the enum!
};

// GC Metadata

struct StructNewMetadata {
    uint32_t type;
    uint16_t params;
    uint8_t length;
};

struct StructNewDefaultMetadata {
    uint32_t type;
    uint8_t length;
};

struct StructGetSetMetadata {
    uint32_t fieldIndex;
    uint8_t length;
};

struct ArrayNewMetadata {
    uint32_t type;
    uint8_t length;
};

struct ArrayNewFixedMetadata {
    uint32_t type;
    uint32_t arraySize;
    uint8_t length;
};

struct ArrayNewDataMetadata {
    uint32_t type;
    uint32_t dataSegmentIndex;
    uint8_t length;
};

struct ArrayNewElemMetadata {
    uint32_t type;
    uint32_t elemSegmentIndex;
    uint8_t length;
};

struct ArrayGetSetMetadata {
    uint32_t type;
    uint8_t length;
};

struct ArrayFillMetadata {
    uint8_t length;
};

struct ArrayCopyMetadata {
    uint8_t length;
};

struct ArrayInitDataMetadata {
    uint32_t dataSegmentIndex;
    uint8_t length;
};

struct ArrayInitElemMetadata {
    uint32_t elemSegmentIndex;
    uint8_t length;
};

struct RefTestCastMetadata {
    int32_t toHeapType;
    uint8_t length;
};

#pragma pack()

} // namespace JSC::IPInt

} // namespace JSC

#endif // ENABLE(WEBASSEMBLY)
