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// Copyright 2010 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_X64)
#include "codegen-inl.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-x64.cc
// for the precise return instructions sequence.
void BreakLocationIterator::SetDebugBreakAtReturn() {
ASSERT(Assembler::kJSReturnSequenceLength >=
Assembler::kCallInstructionLength);
rinfo()->PatchCodeWithCall(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(v8::internal::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 !Assembler::IsNop(rinfo()->pc());
}
void BreakLocationIterator::SetDebugBreakAtSlot() {
ASSERT(IsDebugBreakSlot());
rinfo()->PatchCodeWithCall(
Debug::debug_break_slot()->entry(),
Assembler::kDebugBreakSlotLength - Assembler::kCallInstructionLength);
}
void BreakLocationIterator::ClearDebugBreakAtSlot() {
ASSERT(IsDebugBreakSlot());
rinfo()->PatchCode(original_rinfo()->pc(), Assembler::kDebugBreakSlotLength);
}
#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.
__ EnterInternalFrame();
// 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 as two smis 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 };
ASSERT(!reg.is(kScratchRegister));
if ((object_regs & (1 << r)) != 0) {
__ push(reg);
}
// Store the 64-bit value as two smis.
if ((non_object_regs & (1 << r)) != 0) {
__ movq(kScratchRegister, reg);
__ Integer32ToSmi(reg, reg);
__ push(reg);
__ sar(kScratchRegister, Immediate(32));
__ Integer32ToSmi(kScratchRegister, kScratchRegister);
__ push(kScratchRegister);
}
}
#ifdef DEBUG
__ RecordComment("// Calling from debug break to runtime - come in - over");
#endif
__ Set(rax, 0); // No arguments (argc == 0).
__ movq(rbx, ExternalReference::debug_break());
CEntryStub ceb(1);
__ CallStub(&ceb);
// Restore the register values from the expression stack.
for (int i = kNumJSCallerSaved - 1; i >= 0; i--) {
int r = JSCallerSavedCode(i);
Register reg = { r };
if (FLAG_debug_code) {
__ Set(reg, kDebugZapValue);
}
if ((object_regs & (1 << r)) != 0) {
__ pop(reg);
}
// Reconstruct the 64-bit value from two smis.
if ((non_object_regs & (1 << r)) != 0) {
__ pop(kScratchRegister);
__ SmiToInteger32(kScratchRegister, kScratchRegister);
__ shl(kScratchRegister, Immediate(32));
__ pop(reg);
__ SmiToInteger32(reg, reg);
__ or_(reg, kScratchRegister);
}
}
// Get rid of the internal frame.
__ LeaveInternalFrame();
// 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) {
__ addq(rsp, 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());
__ movq(kScratchRegister, after_break_target);
__ jmp(Operand(kScratchRegister, 0));
}
void Debug::GenerateLoadICDebugBreak(MacroAssembler* masm) {
// Register state for IC load call (from ic-x64.cc).
// ----------- S t a t e -------------
// -- rax : receiver
// -- rcx : name
// -----------------------------------
Generate_DebugBreakCallHelper(masm, rax.bit() | rcx.bit(), 0, false);
}
void Debug::GenerateStoreICDebugBreak(MacroAssembler* masm) {
// Register state for IC store call (from ic-x64.cc).
// ----------- S t a t e -------------
// -- rax : value
// -- rcx : name
// -- rdx : receiver
// -----------------------------------
Generate_DebugBreakCallHelper(
masm, rax.bit() | rcx.bit() | rdx.bit(), 0, false);
}
void Debug::GenerateKeyedLoadICDebugBreak(MacroAssembler* masm) {
// Register state for keyed IC load call (from ic-x64.cc).
// ----------- S t a t e -------------
// -- rax : key
// -- rdx : receiver
// -----------------------------------
Generate_DebugBreakCallHelper(masm, rax.bit() | rdx.bit(), 0, false);
}
void Debug::GenerateKeyedStoreICDebugBreak(MacroAssembler* masm) {
// Register state for keyed IC load call (from ic-x64.cc).
// ----------- S t a t e -------------
// -- rax : value
// -- rcx : key
// -- rdx : receiver
// -----------------------------------
Generate_DebugBreakCallHelper(
masm, rax.bit() | rcx.bit() | rdx.bit(), 0, false);
}
void Debug::GenerateCallICDebugBreak(MacroAssembler* masm) {
// Register state for IC call call (from ic-x64.cc)
// ----------- S t a t e -------------
// -- rcx: function name
// -----------------------------------
Generate_DebugBreakCallHelper(masm, rcx.bit(), 0, false);
}
void Debug::GenerateConstructCallDebugBreak(MacroAssembler* masm) {
// Register state just before return from JS function (from codegen-x64.cc).
// rax is the actual number of arguments not encoded as a smi, see comment
// above IC call.
// ----------- S t a t e -------------
// -- rax: number of arguments
// -----------------------------------
// The number of arguments in rax is not smi encoded.
Generate_DebugBreakCallHelper(masm, rdi.bit(), rax.bit(), false);
}
void Debug::GenerateReturnDebugBreak(MacroAssembler* masm) {
// Register state just before return from JS function (from codegen-x64.cc).
// ----------- S t a t e -------------
// -- rax: return value
// -----------------------------------
Generate_DebugBreakCallHelper(masm, rax.bit(), 0, true);
}
void Debug::GenerateStubNoRegistersDebugBreak(MacroAssembler* masm) {
// Register state for stub CallFunction (from CallFunctionStub in ic-x64.cc).
// ----------- S t a t e -------------
// No registers used on entry.
// -----------------------------------
Generate_DebugBreakCallHelper(masm, 0, 0, false);
}
void Debug::GenerateSlot(MacroAssembler* masm) {
// Generate enough nop's to make space for a call instruction.
Label check_codesize;
__ bind(&check_codesize);
__ RecordDebugBreakSlot();
for (int i = 0; i < Assembler::kDebugBreakSlotLength; i++) {
__ nop();
}
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());
__ movq(rax, restarter_frame_function_slot);
__ movq(Operand(rax, 0), Immediate(0));
// We do not know our frame height, but set rsp based on rbp.
__ lea(rsp, Operand(rbp, -1 * kPointerSize));
__ pop(rdi); // Function.
__ pop(rbp);
// Load context from the function.
__ movq(rsi, FieldOperand(rdi, JSFunction::kContextOffset));
// Get function code.
__ movq(rdx, FieldOperand(rdi, JSFunction::kSharedFunctionInfoOffset));
__ movq(rdx, FieldOperand(rdx, SharedFunctionInfo::kCodeOffset));
__ lea(rdx, FieldOperand(rdx, Code::kHeaderSize));
// Re-run JSFunction, rdi is function, rsi is context.
__ jmp(rdx);
}
const bool Debug::kFrameDropperSupported = true;
#undef __
#endif // ENABLE_DEBUGGER_SUPPORT
} } // namespace v8::internal
#endif // V8_TARGET_ARCH_X64