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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_MIPS)
#include "codegen.h"
#include "debug.h"
namespace v8 {
namespace internal {
#ifdef ENABLE_DEBUGGER_SUPPORT
bool BreakLocationIterator::IsDebugBreakAtReturn() {
return Debug::IsDebugBreakAtReturn(rinfo());
}
void BreakLocationIterator::SetDebugBreakAtReturn() {
// Mips return sequence:
// mov sp, fp
// lw fp, sp(0)
// lw ra, sp(4)
// addiu sp, sp, 8
// addiu sp, sp, N
// jr ra
// nop (in branch delay slot)
// Make sure this constant matches the number if instrucntions we emit.
ASSERT(Assembler::kJSReturnSequenceInstructions == 7);
CodePatcher patcher(rinfo()->pc(), Assembler::kJSReturnSequenceInstructions);
// li and Call pseudo-instructions emit two instructions each.
patcher.masm()->li(v8::internal::t9,
Operand(reinterpret_cast<int32_t>(
Isolate::Current()->debug()->debug_break_return()->entry())));
patcher.masm()->Call(v8::internal::t9);
patcher.masm()->nop();
patcher.masm()->nop();
patcher.masm()->nop();
// TODO(mips): Open issue about using breakpoint instruction instead of nops.
// patcher.masm()->bkpt(0);
}
// Restore the JS frame exit code.
void BreakLocationIterator::ClearDebugBreakAtReturn() {
rinfo()->PatchCode(original_rinfo()->pc(),
Assembler::kJSReturnSequenceInstructions);
}
// A debug break in the exit code is identified by the JS frame exit code
// having been patched with li/call psuedo-instrunction (liu/ori/jalr).
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());
// Patch the code changing the debug break slot code from:
// nop(DEBUG_BREAK_NOP) - nop(1) is sll(zero_reg, zero_reg, 1)
// nop(DEBUG_BREAK_NOP)
// nop(DEBUG_BREAK_NOP)
// nop(DEBUG_BREAK_NOP)
// to a call to the debug break slot code.
// li t9, address (lui t9 / ori t9 instruction pair)
// call t9 (jalr t9 / nop instruction pair)
CodePatcher patcher(rinfo()->pc(), Assembler::kDebugBreakSlotInstructions);
patcher.masm()->li(v8::internal::t9, Operand(reinterpret_cast<int32_t>(
Isolate::Current()->debug()->debug_break_slot()->entry())));
patcher.masm()->Call(v8::internal::t9);
}
void BreakLocationIterator::ClearDebugBreakAtSlot() {
ASSERT(IsDebugBreakSlot());
rinfo()->PatchCode(original_rinfo()->pc(),
Assembler::kDebugBreakSlotInstructions);
}
const bool Debug::FramePaddingLayout::kIsSupported = false;
#define __ ACCESS_MASM(masm)
static void Generate_DebugBreakCallHelper(MacroAssembler* masm,
RegList object_regs,
RegList non_object_regs) {
{
FrameScope scope(masm, StackFrame::INTERNAL);
// 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);
if ((object_regs | non_object_regs) != 0) {
for (int i = 0; i < kNumJSCallerSaved; i++) {
int r = JSCallerSavedCode(i);
Register reg = { r };
if ((non_object_regs & (1 << r)) != 0) {
if (FLAG_debug_code) {
__ And(at, reg, 0xc0000000);
__ Assert(
eq, "Unable to encode value as smi", at, Operand(zero_reg));
}
__ sll(reg, reg, kSmiTagSize);
}
}
__ MultiPush(object_regs | non_object_regs);
}
#ifdef DEBUG
__ RecordComment("// Calling from debug break to runtime - come in - over");
#endif
__ PrepareCEntryArgs(0); // No arguments.
__ PrepareCEntryFunction(ExternalReference::debug_break(masm->isolate()));
CEntryStub ceb(1);
__ CallStub(&ceb);
// Restore the register values from the expression stack.
if ((object_regs | non_object_regs) != 0) {
__ MultiPop(object_regs | non_object_regs);
for (int i = 0; i < kNumJSCallerSaved; i++) {
int r = JSCallerSavedCode(i);
Register reg = { r };
if ((non_object_regs & (1 << r)) != 0) {
__ srl(reg, reg, kSmiTagSize);
}
if (FLAG_debug_code &&
(((object_regs |non_object_regs) & (1 << r)) == 0)) {
__ li(reg, kDebugZapValue);
}
}
}
// Leave the internal frame.
}
// 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.
__ li(t9, Operand(
ExternalReference(Debug_Address::AfterBreakTarget(), masm->isolate())));
__ lw(t9, MemOperand(t9));
__ Jump(t9);
}
void Debug::GenerateLoadICDebugBreak(MacroAssembler* masm) {
// Calling convention for IC load (from ic-mips.cc).
// ----------- S t a t e -------------
// -- a2 : name
// -- ra : return address
// -- a0 : receiver
// -- [sp] : receiver
// -----------------------------------
// Registers a0 and a2 contain objects that need to be pushed on the
// expression stack of the fake JS frame.
Generate_DebugBreakCallHelper(masm, a0.bit() | a2.bit(), 0);
}
void Debug::GenerateStoreICDebugBreak(MacroAssembler* masm) {
// Calling convention for IC store (from ic-mips.cc).
// ----------- S t a t e -------------
// -- a0 : value
// -- a1 : receiver
// -- a2 : name
// -- ra : return address
// -----------------------------------
// Registers a0, a1, and a2 contain objects that need to be pushed on the
// expression stack of the fake JS frame.
Generate_DebugBreakCallHelper(masm, a0.bit() | a1.bit() | a2.bit(), 0);
}
void Debug::GenerateKeyedLoadICDebugBreak(MacroAssembler* masm) {
// ---------- S t a t e --------------
// -- ra : return address
// -- a0 : key
// -- a1 : receiver
Generate_DebugBreakCallHelper(masm, a0.bit() | a1.bit(), 0);
}
void Debug::GenerateKeyedStoreICDebugBreak(MacroAssembler* masm) {
// ---------- S t a t e --------------
// -- a0 : value
// -- a1 : key
// -- a2 : receiver
// -- ra : return address
Generate_DebugBreakCallHelper(masm, a0.bit() | a1.bit() | a2.bit(), 0);
}
void Debug::GenerateCallICDebugBreak(MacroAssembler* masm) {
// Calling convention for IC call (from ic-mips.cc).
// ----------- S t a t e -------------
// -- a2: name
// -----------------------------------
Generate_DebugBreakCallHelper(masm, a2.bit(), 0);
}
void Debug::GenerateReturnDebugBreak(MacroAssembler* masm) {
// In places other than IC call sites it is expected that v0 is TOS which
// is an object - this is not generally the case so this should be used with
// care.
Generate_DebugBreakCallHelper(masm, v0.bit(), 0);
}
void Debug::GenerateCallFunctionStubDebugBreak(MacroAssembler* masm) {
// Register state for CallFunctionStub (from code-stubs-mips.cc).
// ----------- S t a t e -------------
// -- a1 : function
// -----------------------------------
Generate_DebugBreakCallHelper(masm, a1.bit(), 0);
}
void Debug::GenerateCallFunctionStubRecordDebugBreak(MacroAssembler* masm) {
// Register state for CallFunctionStub (from code-stubs-mips.cc).
// ----------- S t a t e -------------
// -- a1 : function
// -- a2 : cache cell for call target
// -----------------------------------
Generate_DebugBreakCallHelper(masm, a1.bit() | a2.bit(), 0);
}
void Debug::GenerateCallConstructStubDebugBreak(MacroAssembler* masm) {
// Calling convention for CallConstructStub (from code-stubs-mips.cc).
// ----------- S t a t e -------------
// -- a0 : number of arguments (not smi)
// -- a1 : constructor function
// -----------------------------------
Generate_DebugBreakCallHelper(masm, a1.bit() , a0.bit());
}
void Debug::GenerateCallConstructStubRecordDebugBreak(MacroAssembler* masm) {
// Calling convention for CallConstructStub (from code-stubs-mips.cc).
// ----------- S t a t e -------------
// -- a0 : number of arguments (not smi)
// -- a1 : constructor function
// -- a2 : cache cell for call target
// -----------------------------------
Generate_DebugBreakCallHelper(masm, a1.bit() | a2.bit(), a0.bit());
}
void Debug::GenerateSlot(MacroAssembler* masm) {
// Generate enough nop's to make space for a call instruction. Avoid emitting
// the trampoline pool in the debug break slot code.
Assembler::BlockTrampolinePoolScope block_trampoline_pool(masm);
Label check_codesize;
__ bind(&check_codesize);
__ RecordDebugBreakSlot();
for (int i = 0; i < Assembler::kDebugBreakSlotInstructions; i++) {
__ nop(MacroAssembler::DEBUG_BREAK_NOP);
}
ASSERT_EQ(Assembler::kDebugBreakSlotInstructions,
masm->InstructionsGeneratedSince(&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);
}
void Debug::GeneratePlainReturnLiveEdit(MacroAssembler* masm) {
masm->Abort("LiveEdit frame dropping is not supported on mips");
}
void Debug::GenerateFrameDropperLiveEdit(MacroAssembler* masm) {
masm->Abort("LiveEdit frame dropping is not supported on mips");
}
const bool Debug::kFrameDropperSupported = false;
#undef __
#endif // ENABLE_DEBUGGER_SUPPORT
} } // namespace v8::internal
#endif // V8_TARGET_ARCH_MIPS