/*
 * Copyright (C) 2019 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
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 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "config.h"
#include "WasmLLIntPlan.h"

#if ENABLE(WEBASSEMBLY)

#include "B3Compilation.h"
#include "BytecodeDumper.h"
#include "CalleeBits.h"
#include "JSToWasm.h"
#include "LLIntThunks.h"
#include "LinkBuffer.h"
#include "WasmCallee.h"
#include "WasmLLIntGenerator.h"
#include "WasmSignatureInlines.h"

namespace JSC { namespace Wasm {

namespace WasmLLIntPlanInternal {
static const bool verbose = false;
}

LLIntPlan::LLIntPlan(Context* context, Vector<uint8_t>&& source, AsyncWork work, CompletionTask&& task)
    : Base(context, WTFMove(source), work, WTFMove(task))
{
    if (parseAndValidateModule(m_source.data(), m_source.size()))
        prepare();
}

LLIntPlan::LLIntPlan(Context* context, Ref<ModuleInformation> info, const Ref<LLIntCallee>* callees, CompletionTask&& task)
    : Base(context, WTFMove(info), AsyncWork::FullCompile, WTFMove(task))
    , m_callees(callees)
{
    ASSERT(m_callees || !m_moduleInformation->functions.size());
    prepare();
    m_currentIndex = m_moduleInformation->functions.size();
}

bool LLIntPlan::prepareImpl()
{
    const auto& functions = m_moduleInformation->functions;
    if (!tryReserveCapacity(m_wasmInternalFunctions, functions.size(), " WebAssembly functions"))
        return false;

    m_wasmInternalFunctions.resize(functions.size());

    return true;
}

void LLIntPlan::compileFunction(uint32_t functionIndex)
{
    const auto& function = m_moduleInformation->functions[functionIndex];
    SignatureIndex signatureIndex = m_moduleInformation->internalFunctionSignatureIndices[functionIndex];
    const Signature& signature = SignatureInformation::get(signatureIndex);
    unsigned functionIndexSpace = m_wasmToWasmExitStubs.size() + functionIndex;
    ASSERT_UNUSED(functionIndexSpace, m_moduleInformation->signatureIndexFromFunctionIndexSpace(functionIndexSpace) == signatureIndex);

    m_unlinkedWasmToWasmCalls[functionIndex] = Vector<UnlinkedWasmToWasmCall>();
    Expected<std::unique_ptr<FunctionCodeBlock>, String> parseAndCompileResult = parseAndCompileBytecode(function.data.data(), function.data.size(), signature, m_moduleInformation.get(), functionIndex);

    if (UNLIKELY(!parseAndCompileResult)) {
        auto locker = holdLock(m_lock);
        if (!m_errorMessage) {
            // Multiple compiles could fail simultaneously. We arbitrarily choose the first.
            fail(locker, makeString(parseAndCompileResult.error(), ", in function at index ", String::number(functionIndex))); // FIXME make this an Expected.
        }
        m_currentIndex = m_moduleInformation->functions.size();
        return;
    }

    m_wasmInternalFunctions[functionIndex] = WTFMove(*parseAndCompileResult);
}

void LLIntPlan::didCompleteCompilation(const AbstractLocker& locker)
{
    unsigned functionCount = m_wasmInternalFunctions.size();
    if (!m_callees && functionCount) {
        // LLInt entrypoint thunks generation
        CCallHelpers jit;
        m_calleesVector.resize(functionCount);
        Vector<CCallHelpers::Label> entrypoints(functionCount);
        Vector<CCallHelpers::Jump> jumps(functionCount);
        for (unsigned i = 0; i < functionCount; ++i) {
            size_t functionIndexSpace = i + m_moduleInformation->importFunctionCount();

            if (UNLIKELY(Options::dumpGeneratedWasmBytecodes()))
                BytecodeDumper::dumpBlock(m_wasmInternalFunctions[i].get(), m_moduleInformation, WTF::dataFile());

            m_calleesVector[i] = LLIntCallee::create(WTFMove(m_wasmInternalFunctions[i]), functionIndexSpace, m_moduleInformation->nameSection->get(functionIndexSpace));
            entrypoints[i] = jit.label();
#if CPU(X86_64)
            CCallHelpers::Address calleeSlot(CCallHelpers::stackPointerRegister, CallFrameSlot::callee * static_cast<int>(sizeof(Register)) - sizeof(CPURegister));
#elif CPU(ARM64)
            CCallHelpers::Address calleeSlot(CCallHelpers::stackPointerRegister, CallFrameSlot::callee * static_cast<int>(sizeof(Register)) - sizeof(CallerFrameAndPC));
#else
#error Unsupported architecture.
#endif
            jit.storePtr(CCallHelpers::TrustedImmPtr(CalleeBits::boxWasm(m_calleesVector[i].ptr())), calleeSlot);
            jumps[i] = jit.jump();
        }

        LinkBuffer linkBuffer(jit, GLOBAL_THUNK_ID, JITCompilationCanFail);
        if (UNLIKELY(linkBuffer.didFailToAllocate())) {
            Base::fail(locker, "Out of executable memory in Wasm LLInt entry thunks");
            return;
        }

        for (unsigned i = 0; i < functionCount; ++i) {
            m_calleesVector[i]->setEntrypoint(linkBuffer.locationOf<WasmEntryPtrTag>(entrypoints[i]));
            linkBuffer.link<JITThunkPtrTag>(jumps[i], CodeLocationLabel<JITThunkPtrTag>(LLInt::wasmFunctionEntryThunk().code()));
        }

        m_entryThunks = FINALIZE_CODE(linkBuffer, B3CompilationPtrTag, "Wasm LLInt entry thunks");
        m_callees = m_calleesVector.data();
    }

    if (m_asyncWork == AsyncWork::Validation)
        return;

    for (uint32_t functionIndex = 0; functionIndex < m_moduleInformation->functions.size(); functionIndex++) {
        if (m_exportedFunctionIndices.contains(functionIndex) || m_moduleInformation->referencedFunctions().contains(functionIndex)) {
            SignatureIndex signatureIndex = m_moduleInformation->internalFunctionSignatureIndices[functionIndex];
            const Signature& signature = SignatureInformation::get(signatureIndex);
            CCallHelpers jit;
            std::unique_ptr<InternalFunction> function = createJSToWasmWrapper(jit, signature, &m_unlinkedWasmToWasmCalls[functionIndex], m_moduleInformation.get(), m_mode, functionIndex);

            LinkBuffer linkBuffer(jit, nullptr, JITCompilationCanFail);
            if (UNLIKELY(linkBuffer.didFailToAllocate())) {
                Base::fail(locker, makeString("Out of executable memory in function entrypoint at index ", String::number(functionIndex)));
                return;
            }

            function->entrypoint.compilation = makeUnique<B3::Compilation>(
                FINALIZE_CODE(linkBuffer, B3CompilationPtrTag, "Embedder->WebAssembly entrypoint[%i] %s", functionIndex, signature.toString().ascii().data()),
                nullptr);

            Ref<EmbedderEntrypointCallee> callee = EmbedderEntrypointCallee::create(WTFMove(function->entrypoint));
            // FIXME: remove this repatchPointer - just pass in the callee directly
            // https://bugs.webkit.org/show_bug.cgi?id=166462
            if (function->calleeMoveLocation)
                MacroAssembler::repatchPointer(function->calleeMoveLocation, CalleeBits::boxWasm(callee.ptr()));

            auto result = m_embedderCallees.add(functionIndex, WTFMove(callee));
            ASSERT_UNUSED(result, result.isNewEntry);
        }
    }

    for (auto& unlinked : m_unlinkedWasmToWasmCalls) {
        for (auto& call : unlinked) {
            MacroAssemblerCodePtr<WasmEntryPtrTag> executableAddress;
            if (m_moduleInformation->isImportedFunctionFromFunctionIndexSpace(call.functionIndexSpace)) {
                // FIXME: imports could have been linked in B3, instead of generating a patchpoint. This condition should be replaced by a RELEASE_ASSERT.
                // https://bugs.webkit.org/show_bug.cgi?id=166462
                executableAddress = m_wasmToWasmExitStubs.at(call.functionIndexSpace).code();
            } else
                executableAddress = m_callees[call.functionIndexSpace - m_moduleInformation->importFunctionCount()]->entrypoint();
            MacroAssembler::repatchNearCall(call.callLocation, CodeLocationLabel<WasmEntryPtrTag>(executableAddress));
        }
    }
}

void LLIntPlan::work(CompilationEffort effort)
{
    switch (m_state) {
    case State::Prepared:
        compileFunctions(effort);
        break;
    case State::Compiled:
        break;
    default:
        break;
    }
}

bool LLIntPlan::didReceiveFunctionData(unsigned, const FunctionData&)
{
    // Validation is done inline by the parser
    return true;
}

} } // namespace JSC::Wasm

#endif // ENABLE(WEBASSEMBLY)