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DEFINITIONS
This source file includes following definitions.
- IsDebugBreakAtReturn
- SetDebugBreakAtReturn
- ClearDebugBreakAtReturn
- IsDebugBreakAtReturn
- IsDebugBreakAtSlot
- SetDebugBreakAtSlot
- ClearDebugBreakAtSlot
- Generate_DebugBreakCallHelper
- GenerateLoadICDebugBreak
- GenerateStoreICDebugBreak
- GenerateKeyedLoadICDebugBreak
- GenerateKeyedStoreICDebugBreak
- GenerateCallICDebugBreak
- GenerateReturnDebugBreak
- GenerateCallFunctionStubDebugBreak
- GenerateCallFunctionStubRecordDebugBreak
- GenerateCallConstructStubDebugBreak
- GenerateCallConstructStubRecordDebugBreak
- GenerateSlot
- GenerateSlotDebugBreak
- GeneratePlainReturnLiveEdit
- GenerateFrameDropperLiveEdit
// Copyright 2012 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * 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.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "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 THE COPYRIGHT
// OWNER 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.
#include "v8.h"
#if defined(V8_TARGET_ARCH_IA32)
#include "codegen.h"
#include "debug.h"
namespace v8 {
namespace internal {
#ifdef ENABLE_DEBUGGER_SUPPORT
bool BreakLocationIterator::IsDebugBreakAtReturn() {
return Debug::IsDebugBreakAtReturn(rinfo());
}
// Patch the JS frame exit code with a debug break call. See
// CodeGenerator::VisitReturnStatement and VirtualFrame::Exit in codegen-ia32.cc
// for the precise return instructions sequence.
void BreakLocationIterator::SetDebugBreakAtReturn() {
ASSERT(Assembler::kJSReturnSequenceLength >=
Assembler::kCallInstructionLength);
Isolate* isolate = Isolate::Current();
rinfo()->PatchCodeWithCall(isolate->debug()->debug_break_return()->entry(),
Assembler::kJSReturnSequenceLength - Assembler::kCallInstructionLength);
}
// Restore the JS frame exit code.
void BreakLocationIterator::ClearDebugBreakAtReturn() {
rinfo()->PatchCode(original_rinfo()->pc(),
Assembler::kJSReturnSequenceLength);
}
// A debug break in the frame exit code is identified by the JS frame exit code
// having been patched with a call instruction.
bool Debug::IsDebugBreakAtReturn(RelocInfo* rinfo) {
ASSERT(RelocInfo::IsJSReturn(rinfo->rmode()));
return rinfo->IsPatchedReturnSequence();
}
bool BreakLocationIterator::IsDebugBreakAtSlot() {
ASSERT(IsDebugBreakSlot());
// Check whether the debug break slot instructions have been patched.
return rinfo()->IsPatchedDebugBreakSlotSequence();
}
void BreakLocationIterator::SetDebugBreakAtSlot() {
ASSERT(IsDebugBreakSlot());
Isolate* isolate = Isolate::Current();
rinfo()->PatchCodeWithCall(
isolate->debug()->debug_break_slot()->entry(),
Assembler::kDebugBreakSlotLength - Assembler::kCallInstructionLength);
}
void BreakLocationIterator::ClearDebugBreakAtSlot() {
ASSERT(IsDebugBreakSlot());
rinfo()->PatchCode(original_rinfo()->pc(), Assembler::kDebugBreakSlotLength);
}
// All debug break stubs support padding for LiveEdit.
const bool Debug::FramePaddingLayout::kIsSupported = true;
#define __ ACCESS_MASM(masm)
static void Generate_DebugBreakCallHelper(MacroAssembler* masm,
RegList object_regs,
RegList non_object_regs,
bool convert_call_to_jmp) {
// Enter an internal frame.
{
FrameScope scope(masm, StackFrame::INTERNAL);
// Load padding words on stack.
for (int i = 0; i < Debug::FramePaddingLayout::kInitialSize; i++) {
__ push(Immediate(Smi::FromInt(
Debug::FramePaddingLayout::kPaddingValue)));
}
__ push(Immediate(Smi::FromInt(Debug::FramePaddingLayout::kInitialSize)));
// Store the registers containing live values on the expression stack to
// make sure that these are correctly updated during GC. Non object values
// are stored as a smi causing it to be untouched by GC.
ASSERT((object_regs & ~kJSCallerSaved) == 0);
ASSERT((non_object_regs & ~kJSCallerSaved) == 0);
ASSERT((object_regs & non_object_regs) == 0);
for (int i = 0; i < kNumJSCallerSaved; i++) {
int r = JSCallerSavedCode(i);
Register reg = { r };
if ((object_regs & (1 << r)) != 0) {
__ push(reg);
}
if ((non_object_regs & (1 << r)) != 0) {
if (FLAG_debug_code) {
__ test(reg, Immediate(0xc0000000));
__ Assert(zero, "Unable to encode value as smi");
}
__ SmiTag(reg);
__ push(reg);
}
}
#ifdef DEBUG
__ RecordComment("// Calling from debug break to runtime - come in - over");
#endif
__ Set(eax, Immediate(0)); // No arguments.
__ mov(ebx, Immediate(ExternalReference::debug_break(masm->isolate())));
CEntryStub ceb(1);
__ CallStub(&ceb);
// Automatically find register that could be used after register restore.
// We need one register for padding skip instructions.
Register unused_reg = { -1 };
// Restore the register values containing object pointers from the
// expression stack.
for (int i = kNumJSCallerSaved; --i >= 0;) {
int r = JSCallerSavedCode(i);
Register reg = { r };
if (FLAG_debug_code) {
__ Set(reg, Immediate(kDebugZapValue));
}
bool taken = reg.code() == esi.code();
if ((object_regs & (1 << r)) != 0) {
__ pop(reg);
taken = true;
}
if ((non_object_regs & (1 << r)) != 0) {
__ pop(reg);
__ SmiUntag(reg);
taken = true;
}
if (!taken) {
unused_reg = reg;
}
}
ASSERT(unused_reg.code() != -1);
// Read current padding counter and skip corresponding number of words.
__ pop(unused_reg);
// We divide stored value by 2 (untagging) and multiply it by word's size.
STATIC_ASSERT(kSmiTagSize == 1 && kSmiShiftSize == 0);
__ lea(esp, Operand(esp, unused_reg, times_half_pointer_size, 0));
// Get rid of the internal frame.
}
// If this call did not replace a call but patched other code then there will
// be an unwanted return address left on the stack. Here we get rid of that.
if (convert_call_to_jmp) {
__ add(esp, Immediate(kPointerSize));
}
// Now that the break point has been handled, resume normal execution by
// jumping to the target address intended by the caller and that was
// overwritten by the address of DebugBreakXXX.
ExternalReference after_break_target =
ExternalReference(Debug_Address::AfterBreakTarget(), masm->isolate());
__ jmp(Operand::StaticVariable(after_break_target));
}
void Debug::GenerateLoadICDebugBreak(MacroAssembler* masm) {
// Register state for IC load call (from ic-ia32.cc).
// ----------- S t a t e -------------
// -- ecx : name
// -- edx : receiver
// -----------------------------------
Generate_DebugBreakCallHelper(masm, ecx.bit() | edx.bit(), 0, false);
}
void Debug::GenerateStoreICDebugBreak(MacroAssembler* masm) {
// Register state for IC store call (from ic-ia32.cc).
// ----------- S t a t e -------------
// -- eax : value
// -- ecx : name
// -- edx : receiver
// -----------------------------------
Generate_DebugBreakCallHelper(
masm, eax.bit() | ecx.bit() | edx.bit(), 0, false);
}
void Debug::GenerateKeyedLoadICDebugBreak(MacroAssembler* masm) {
// Register state for keyed IC load call (from ic-ia32.cc).
// ----------- S t a t e -------------
// -- ecx : key
// -- edx : receiver
// -----------------------------------
Generate_DebugBreakCallHelper(masm, ecx.bit() | edx.bit(), 0, false);
}
void Debug::GenerateKeyedStoreICDebugBreak(MacroAssembler* masm) {
// Register state for keyed IC load call (from ic-ia32.cc).
// ----------- S t a t e -------------
// -- eax : value
// -- ecx : key
// -- edx : receiver
// -----------------------------------
Generate_DebugBreakCallHelper(
masm, eax.bit() | ecx.bit() | edx.bit(), 0, false);
}
void Debug::GenerateCallICDebugBreak(MacroAssembler* masm) {
// Register state for keyed IC call call (from ic-ia32.cc)
// ----------- S t a t e -------------
// -- ecx: name
// -----------------------------------
Generate_DebugBreakCallHelper(masm, ecx.bit(), 0, false);
}
void Debug::GenerateReturnDebugBreak(MacroAssembler* masm) {
// Register state just before return from JS function (from codegen-ia32.cc).
// ----------- S t a t e -------------
// -- eax: return value
// -----------------------------------
Generate_DebugBreakCallHelper(masm, eax.bit(), 0, true);
}
void Debug::GenerateCallFunctionStubDebugBreak(MacroAssembler* masm) {
// Register state for CallFunctionStub (from code-stubs-ia32.cc).
// ----------- S t a t e -------------
// -- edi: function
// -----------------------------------
Generate_DebugBreakCallHelper(masm, edi.bit(), 0, false);
}
void Debug::GenerateCallFunctionStubRecordDebugBreak(MacroAssembler* masm) {
// Register state for CallFunctionStub (from code-stubs-ia32.cc).
// ----------- S t a t e -------------
// -- ebx: cache cell for call target
// -- edi: function
// -----------------------------------
Generate_DebugBreakCallHelper(masm, ebx.bit() | edi.bit(), 0, false);
}
void Debug::GenerateCallConstructStubDebugBreak(MacroAssembler* masm) {
// Register state for CallConstructStub (from code-stubs-ia32.cc).
// eax is the actual number of arguments not encoded as a smi see comment
// above IC call.
// ----------- S t a t e -------------
// -- eax: number of arguments (not smi)
// -- edi: constructor function
// -----------------------------------
// The number of arguments in eax is not smi encoded.
Generate_DebugBreakCallHelper(masm, edi.bit(), eax.bit(), false);
}
void Debug::GenerateCallConstructStubRecordDebugBreak(MacroAssembler* masm) {
// Register state for CallConstructStub (from code-stubs-ia32.cc).
// eax is the actual number of arguments not encoded as a smi see comment
// above IC call.
// ----------- S t a t e -------------
// -- eax: number of arguments (not smi)
// -- ebx: cache cell for call target
// -- edi: constructor function
// -----------------------------------
// The number of arguments in eax is not smi encoded.
Generate_DebugBreakCallHelper(masm, ebx.bit() | edi.bit(), eax.bit(), false);
}
void Debug::GenerateSlot(MacroAssembler* masm) {
// Generate enough nop's to make space for a call instruction.
Label check_codesize;
__ bind(&check_codesize);
__ RecordDebugBreakSlot();
__ Nop(Assembler::kDebugBreakSlotLength);
ASSERT_EQ(Assembler::kDebugBreakSlotLength,
masm->SizeOfCodeGeneratedSince(&check_codesize));
}
void Debug::GenerateSlotDebugBreak(MacroAssembler* masm) {
// In the places where a debug break slot is inserted no registers can contain
// object pointers.
Generate_DebugBreakCallHelper(masm, 0, 0, true);
}
void Debug::GeneratePlainReturnLiveEdit(MacroAssembler* masm) {
masm->ret(0);
}
void Debug::GenerateFrameDropperLiveEdit(MacroAssembler* masm) {
ExternalReference restarter_frame_function_slot =
ExternalReference(Debug_Address::RestarterFrameFunctionPointer(),
masm->isolate());
__ mov(Operand::StaticVariable(restarter_frame_function_slot), Immediate(0));
// We do not know our frame height, but set esp based on ebp.
__ lea(esp, Operand(ebp, -1 * kPointerSize));
__ pop(edi); // Function.
__ pop(ebp);
// Load context from the function.
__ mov(esi, FieldOperand(edi, JSFunction::kContextOffset));
// Get function code.
__ mov(edx, FieldOperand(edi, JSFunction::kSharedFunctionInfoOffset));
__ mov(edx, FieldOperand(edx, SharedFunctionInfo::kCodeOffset));
__ lea(edx, FieldOperand(edx, Code::kHeaderSize));
// Re-run JSFunction, edi is function, esi is context.
__ jmp(edx);
}
const bool Debug::kFrameDropperSupported = true;
#undef __
#endif // ENABLE_DEBUGGER_SUPPORT
} } // namespace v8::internal
#endif // V8_TARGET_ARCH_IA32