// Copyright 2013 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "src/api/api.h"
#include "src/codegen/flush-instruction-cache.h"
#include "src/codegen/macro-assembler.h"
#include "src/common/code-memory-access-inl.h"
#include "src/deoptimizer/deoptimizer.h"
#include "src/execution/pointer-authentication.h"

namespace v8 {
namespace internal {

const int Deoptimizer::kEagerDeoptExitSize = kInstrSize;
#ifdef V8_ENABLE_CONTROL_FLOW_INTEGRITY
const int Deoptimizer::kLazyDeoptExitSize = 2 * kInstrSize;
#else
const int Deoptimizer::kLazyDeoptExitSize = 1 * kInstrSize;
#endif

const int Deoptimizer::kAdaptShadowStackOffsetToSubtract = 0;

// static
void Deoptimizer::ZapCode(Address start, Address end, RelocIterator& it) {
  // TODO(422364570): Support this platform.
}

// static
void Deoptimizer::PatchToJump(Address pc, Address new_pc) {
  RwxMemoryWriteScope rwx_write_scope("Patch jump to deopt trampoline");
  intptr_t offset = (new_pc - pc) / kInstrSize;
  // We'll overwrite only one instruction of 4-bytes. Give enough
  // space not to try to grow the buffer.
  constexpr int kSize = 128;
  AccountingAllocator allocator;
  Assembler masm(
      &allocator, AssemblerOptions{},
      ExternalAssemblerBuffer(reinterpret_cast<uint8_t*>(pc), kSize));
  masm.b(static_cast<int>(offset));
  FlushInstructionCache(pc, kSize);
}

Float32 RegisterValues::GetFloatRegister(unsigned n) const {
  V8_ASSUME(n < arraysize(simd128_registers_));
  return base::ReadUnalignedValue<Float32>(
      reinterpret_cast<Address>(simd128_registers_ + n));
}

Float64 RegisterValues::GetDoubleRegister(unsigned n) const {
  V8_ASSUME(n < arraysize(simd128_registers_));
  return base::ReadUnalignedValue<Float64>(
      reinterpret_cast<Address>(simd128_registers_ + n));
}

void RegisterValues::SetDoubleRegister(unsigned n, Float64 value) {
  V8_ASSUME(n < arraysize(simd128_registers_));
  base::WriteUnalignedValue(reinterpret_cast<Address>(simd128_registers_ + n),
                            value);
}

void FrameDescription::SetCallerPc(unsigned offset, intptr_t value) {
  Address new_context =
      static_cast<Address>(GetTop()) + offset + kPCOnStackSize;
  value = PointerAuthentication::SignAndCheckPC(isolate_, value, new_context);
  SetFrameSlot(offset, value);
}

void FrameDescription::SetCallerFp(unsigned offset, intptr_t value) {
  SetFrameSlot(offset, value);
}

void FrameDescription::SetCallerConstantPool(unsigned offset, intptr_t value) {
  // No embedded constant pool support.
  UNREACHABLE();
}

void FrameDescription::SetPc(intptr_t pc) {
  // TODO(v8:10026): We need to sign pointers to the embedded blob, which are
  // stored in the isolate and code range objects.
  if (ENABLE_CONTROL_FLOW_INTEGRITY_BOOL) {
    Deoptimizer::EnsureValidReturnAddress(isolate_,
                                          PointerAuthentication::StripPAC(pc));
  }
  pc_ = pc;
}

}  // namespace internal
}  // namespace v8