blob: 2bd3f1bebadba5accef9d8108e47c2b1f1fe9e22 [file] [log] [blame]
// Copyright (c) 2012, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
#include "vm/globals.h" // Needed here to get TARGET_ARCH_IA32.
#if defined(TARGET_ARCH_IA32)
#include "vm/assembler.h"
#include "vm/code_patcher.h"
#include "vm/cpu.h"
#include "vm/dart_entry.h"
#include "vm/instructions.h"
#include "vm/object.h"
#include "vm/raw_object.h"
namespace dart {
// The pattern of a Dart instance call is:
// 1: mov ECX, immediate 1
// 2: mov EDX, immediate 2
// 3: call target_address
// <- return_address
class DartCallPattern : public ValueObject {
public:
explicit DartCallPattern(uword return_address)
: start_(return_address - (kNumInstructions * kInstructionSize)) {
ASSERT(IsValid(return_address));
ASSERT(kInstructionSize == Assembler::kCallExternalLabelSize);
}
static bool IsValid(uword return_address) {
uint8_t* code_bytes =
reinterpret_cast<uint8_t*>(
return_address - (kNumInstructions * kInstructionSize));
return (code_bytes[0] == 0xB9) &&
(code_bytes[kInstructionSize] == 0xBA) &&
(code_bytes[2 * kInstructionSize] == 0xE8);
}
uword target() const {
const uword offset = *reinterpret_cast<uword*>(call_address() + 1);
return return_address() + offset;
}
void set_target(uword target) const {
uword* target_addr = reinterpret_cast<uword*>(call_address() + 1);
uword offset = target - return_address();
*target_addr = offset;
CPU::FlushICache(call_address(), kInstructionSize);
}
RawObject* immediate_one() const {
return *reinterpret_cast<RawObject**>(start_ + 1);
}
RawObject* immediate_two() const {
return *reinterpret_cast<RawObject**>(start_ + kInstructionSize + 1);
}
static const int kNumInstructions = 3;
static const int kInstructionSize = 5; // All instructions have same length.
private:
uword return_address() const {
return start_ + kNumInstructions * kInstructionSize;
}
uword call_address() const {
return start_ + 2 * kInstructionSize;
}
uword start_;
DISALLOW_IMPLICIT_CONSTRUCTORS(DartCallPattern);
};
// The expected pattern of a dart instance call:
// mov ECX, ic-data
// mov EDX, arguments_descriptor_array
// call target_address
// <- return address
class InstanceCall : public DartCallPattern {
public:
explicit InstanceCall(uword return_address)
: DartCallPattern(return_address) {}
RawObject* ic_data() const { return immediate_one(); }
RawObject* arguments_descriptor() const { return immediate_two(); }
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(InstanceCall);
};
// The expected pattern of a dart static call:
// mov EDX, arguments_descriptor_array (optional in polymorphic calls)
// call target_address
// <- return address
class StaticCall : public ValueObject {
public:
explicit StaticCall(uword return_address)
: start_(return_address - (kNumInstructions * kInstructionSize)) {
ASSERT(IsValid(return_address));
ASSERT(kInstructionSize == Assembler::kCallExternalLabelSize);
}
static bool IsValid(uword return_address) {
uint8_t* code_bytes =
reinterpret_cast<uint8_t*>(
return_address - (kNumInstructions * kInstructionSize));
return (code_bytes[0] == 0xE8);
}
uword target() const {
const uword offset = *reinterpret_cast<uword*>(call_address() + 1);
return return_address() + offset;
}
void set_target(uword target) const {
uword* target_addr = reinterpret_cast<uword*>(call_address() + 1);
uword offset = target - return_address();
*target_addr = offset;
CPU::FlushICache(call_address(), kInstructionSize);
}
static const int kNumInstructions = 1;
static const int kInstructionSize = 5; // All instructions have same length.
private:
uword return_address() const {
return start_ + kNumInstructions * kInstructionSize;
}
uword call_address() const {
return start_;
}
uword start_;
DISALLOW_IMPLICIT_CONSTRUCTORS(StaticCall);
};
uword CodePatcher::GetStaticCallTargetAt(uword return_address,
const Code& code) {
ASSERT(code.ContainsInstructionAt(return_address));
StaticCall call(return_address);
return call.target();
}
void CodePatcher::PatchStaticCallAt(uword return_address,
const Code& code,
uword new_target) {
ASSERT(code.ContainsInstructionAt(return_address));
StaticCall call(return_address);
call.set_target(new_target);
}
void CodePatcher::PatchInstanceCallAt(uword return_address,
const Code& code,
uword new_target) {
ASSERT(code.ContainsInstructionAt(return_address));
InstanceCall call(return_address);
call.set_target(new_target);
}
void CodePatcher::InsertCallAt(uword start, uword target) {
*reinterpret_cast<uint8_t*>(start) = 0xE8;
CallPattern call(start);
call.SetTargetAddress(target);
CPU::FlushICache(start, CallPattern::InstructionLength());
}
uword CodePatcher::GetInstanceCallAt(uword return_address,
const Code& code,
ICData* ic_data,
Array* arguments_descriptor) {
ASSERT(code.ContainsInstructionAt(return_address));
InstanceCall call(return_address);
if (ic_data != NULL) {
*ic_data ^= call.ic_data();
}
if (arguments_descriptor != NULL) {
*arguments_descriptor ^= call.arguments_descriptor();
}
return call.target();
}
intptr_t CodePatcher::InstanceCallSizeInBytes() {
return DartCallPattern::kNumInstructions * DartCallPattern::kInstructionSize;
}
} // namespace dart
#endif // defined TARGET_ARCH_IA32