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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"
#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-ia32.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(RelocInfo* rinfo) {
ASSERT(RelocInfo::IsJSReturn(rinfo->rmode()));
return rinfo->IsPatchedReturnSequence();
}
#define __ ACCESS_MASM(masm)
static void Generate_DebugBreakCallHelper(MacroAssembler* masm,
RegList pointer_regs,
bool convert_call_to_jmp) {
// Save the content of all general purpose registers in memory. This copy in
// memory is later pushed onto the JS expression stack for the fake JS frame
// generated and also to the C frame generated on top of that. In the JS
// frame ONLY the registers containing pointers will be pushed on the
// expression stack. This causes the GC to update these pointers so that
// they will have the correct value when returning from the debugger.
__ SaveRegistersToMemory(kJSCallerSaved);
// Enter an internal frame.
__ EnterInternalFrame();
// Store the registers containing object pointers on the expression stack to
// make sure that these are correctly updated during GC.
__ PushRegistersFromMemory(pointer_regs);
#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()));
CEntryStub ceb(1, ExitFrame::MODE_DEBUG);
__ CallStub(&ceb);
// Restore the register values containing object pointers from the expression
// stack in the reverse order as they where pushed.
__ PopRegistersToMemory(pointer_regs);
// 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) {
__ pop(eax);
}
// Finally restore all registers.
__ RestoreRegistersFromMemory(kJSCallerSaved);
// 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());
__ 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 -------------
// -- eax : receiver
// -- ecx : name
// -----------------------------------
Generate_DebugBreakCallHelper(masm, eax.bit() | ecx.bit(), 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(), false);
}
void Debug::GenerateKeyedLoadICDebugBreak(MacroAssembler* masm) {
// Register state for keyed IC load call (from ic-ia32.cc).
// ----------- S t a t e -------------
// No registers used on entry.
// -----------------------------------
Generate_DebugBreakCallHelper(masm, 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
// -----------------------------------
// Register eax contains an object that needs to be pushed on the
// expression stack of the fake JS frame.
Generate_DebugBreakCallHelper(masm, eax.bit(), false);
}
void Debug::GenerateCallICDebugBreak(MacroAssembler* masm) {
// Register state for keyed IC call call (from ic-ia32.cc)
// ----------- S t a t e -------------
// -- eax: number of arguments
// -----------------------------------
// The number of arguments in eax is not smi encoded.
Generate_DebugBreakCallHelper(masm, 0, false);
}
void Debug::GenerateConstructCallDebugBreak(MacroAssembler* masm) {
// Register state just before return from JS function (from codegen-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
// -----------------------------------
// The number of arguments in eax is not smi encoded.
Generate_DebugBreakCallHelper(masm, 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(), true);
}
void Debug::GenerateStubNoRegistersDebugBreak(MacroAssembler* masm) {
// Register state for stub CallFunction (from CallFunctionStub in ic-ia32.cc).
// ----------- S t a t e -------------
// No registers used on entry.
// -----------------------------------
Generate_DebugBreakCallHelper(masm, 0, false);
}
#undef __
#endif // ENABLE_DEBUGGER_SUPPORT
} } // namespace v8::internal