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// 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.
// Class for patching compiled code.
#ifndef RUNTIME_VM_CODE_PATCHER_H_
#define RUNTIME_VM_CODE_PATCHER_H_
#include "vm/allocation.h"
#include "vm/native_entry.h"
namespace dart {
// Forward declaration.
class Code;
class ICData;
#if defined(TARGET_ARCH_IA32)
// Stack-allocated class to create a scope where the specified region
// [address, address + size] has write access enabled. This is used
// when patching generated code. Access is reset to read-execute in
// the destructor of this scope.
// Dual mapping of instructions pages is not supported on these target arch.
class WritableInstructionsScope : public ValueObject {
public:
WritableInstructionsScope(uword address, intptr_t size);
~WritableInstructionsScope();
private:
const uword address_;
const intptr_t size_;
};
#endif // defined(TARGET_ARCH_IA32)
class CodePatcher : public AllStatic {
public:
// Dart static calls have a distinct, machine-dependent code pattern.
// Patch static call before return_address in given code to the new target.
static void PatchStaticCallAt(uword return_address,
const Code& code,
const Code& new_target);
// Return the target address of the static call before return_address
// in given code.
static CodePtr GetStaticCallTargetAt(uword return_address, const Code& code);
// Get instance call information. Returns the call target and sets the output
// parameter data if non-null.
static CodePtr GetInstanceCallAt(uword return_address,
const Code& caller_code,
Object* data);
// Change the state of an instance call by patching the corresponding object
// pool entries (non-IA32) or instructions (IA32).
static void PatchInstanceCallAt(uword return_address,
const Code& caller_code,
const Object& data,
const Code& target);
static void PatchInstanceCallAtWithMutatorsStopped(Thread* thread,
uword return_address,
const Code& caller_code,
const Object& data,
const Code& target);
// Return target of an unoptimized static call and its ICData object
// (calls target via a stub).
static FunctionPtr GetUnoptimizedStaticCallAt(uword return_address,
const Code& code,
ICData* ic_data);
static void InsertDeoptimizationCallAt(uword start);
static void PatchPoolPointerCallAt(uword return_address,
const Code& code,
const Code& new_target);
static void PatchSwitchableCallAt(uword return_address,
const Code& caller_code,
const Object& data,
const Code& target);
static void PatchSwitchableCallAtWithMutatorsStopped(Thread* thread,
uword return_address,
const Code& caller_code,
const Object& data,
const Code& target);
static ObjectPtr GetSwitchableCallDataAt(uword return_address,
const Code& caller_code);
static uword GetSwitchableCallTargetEntryAt(uword return_address,
const Code& caller_code);
static CodePtr GetNativeCallAt(uword return_address,
const Code& caller_code,
NativeFunction* target);
static void PatchNativeCallAt(uword return_address,
const Code& caller_code,
NativeFunction target,
const Code& trampoline);
static intptr_t GetSubtypeTestCachePoolIndex(uword return_address);
};
// Beginning from [end - size] we compare [size] bytes with [pattern]. All
// [0..255] values in [pattern] have to match, negative values are skipped.
//
// Example pattern: `[0x3d, 0x8b, -1, -1]`.
bool MatchesPattern(uword end, const int16_t* pattern, intptr_t size);
} // namespace dart
#endif // RUNTIME_VM_CODE_PATCHER_H_