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// Copyright 2015 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "src/v8.h"
#if V8_TARGET_ARCH_S390
#include "src/debug/debug.h"
#include "src/codegen.h"
#include "src/debug/liveedit.h"
namespace v8 {
namespace internal {
#define __ ACCESS_MASM(masm)
void EmitDebugBreakSlot(MacroAssembler* masm) {
Label check_size;
__ bind(&check_size);
// oill r3, 0
// oill r3, 0
__ nop(Assembler::DEBUG_BREAK_NOP);
__ nop(Assembler::DEBUG_BREAK_NOP);
// lr r0, r0 64-bit only
// lr r0, r0 64-bit only
// lr r0, r0 64-bit only
for (int i = 8; i < Assembler::kDebugBreakSlotLength; i += 2) {
__ nop();
}
DCHECK_EQ(Assembler::kDebugBreakSlotLength,
masm->SizeOfCodeGeneratedSince(&check_size));
}
void DebugCodegen::GenerateSlot(MacroAssembler* masm, RelocInfo::Mode mode) {
// Generate enough nop's to make space for a call instruction.
masm->RecordDebugBreakSlot(mode);
EmitDebugBreakSlot(masm);
}
void DebugCodegen::ClearDebugBreakSlot(Isolate* isolate, Address pc) {
CodePatcher patcher(isolate, pc, Assembler::kDebugBreakSlotLength);
EmitDebugBreakSlot(patcher.masm());
}
void DebugCodegen::PatchDebugBreakSlot(Isolate* isolate, Address pc,
Handle<Code> code) {
DCHECK(code->is_debug_stub());
CodePatcher patcher(isolate, pc, Assembler::kDebugBreakSlotLength);
// Patch the code changing the debug break slot code from
//
// oill r3, 0
// oill r3, 0
// oill r3, 0 64-bit only
// lr r0, r0 64-bit only
//
// to a call to the debug break code, using a FIXED_SEQUENCE.
//
// iilf r14, <address> 6-bytes
// basr r14, r14A 2-bytes
//
// The 64bit sequence has an extra iihf.
//
// iihf r14, <high 32-bits address> 6-bytes
// iilf r14, <lower 32-bits address> 6-bytes
// basr r14, r14 2-bytes
patcher.masm()->mov(v8::internal::r14,
Operand(reinterpret_cast<intptr_t>(code->entry())));
patcher.masm()->basr(v8::internal::r14, v8::internal::r14);
}
bool DebugCodegen::DebugBreakSlotIsPatched(Address pc) {
Instr current_instr = Assembler::instr_at(pc);
return !Assembler::IsNop(current_instr, Assembler::DEBUG_BREAK_NOP);
}
void DebugCodegen::GenerateDebugBreakStub(MacroAssembler* masm,
DebugBreakCallHelperMode mode) {
__ RecordComment("Debug break");
{
FrameScope scope(masm, StackFrame::INTERNAL);
// Load padding words on stack.
__ LoadSmiLiteral(ip, Smi::FromInt(LiveEdit::kFramePaddingValue));
for (int i = 0; i < LiveEdit::kFramePaddingInitialSize; i++) {
__ push(ip);
}
__ LoadSmiLiteral(ip, Smi::FromInt(LiveEdit::kFramePaddingInitialSize));
__ push(ip);
// Push arguments for DebugBreak call.
if (mode == SAVE_RESULT_REGISTER) {
// Break on return.
__ push(r2);
} else {
// Non-return breaks.
__ Push(masm->isolate()->factory()->the_hole_value());
}
__ mov(r2, Operand(1));
__ mov(r3,
Operand(ExternalReference(
Runtime::FunctionForId(Runtime::kDebugBreak), masm->isolate())));
CEntryStub ceb(masm->isolate(), 1);
__ CallStub(&ceb);
if (FLAG_debug_code) {
for (int i = 0; i < kNumJSCallerSaved; i++) {
Register reg = {JSCallerSavedCode(i)};
// Do not clobber r2 if mode is SAVE_RESULT_REGISTER. It will
// contain return value of the function.
if (!(reg.is(r2) && (mode == SAVE_RESULT_REGISTER))) {
__ mov(reg, Operand(kDebugZapValue));
}
}
}
// Don't bother removing padding bytes pushed on the stack
// as the frame is going to be restored right away.
// 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.
ExternalReference after_break_target =
ExternalReference::debug_after_break_target_address(masm->isolate());
__ mov(ip, Operand(after_break_target));
__ LoadP(ip, MemOperand(ip));
__ JumpToJSEntry(ip);
}
void DebugCodegen::GenerateFrameDropperLiveEdit(MacroAssembler* masm) {
// Load the function pointer off of our current stack frame.
__ LoadP(r3, MemOperand(fp, FrameDropperFrameConstants::kFunctionOffset));
// Pop return address and frame
__ LeaveFrame(StackFrame::INTERNAL);
ParameterCount dummy(0);
__ FloodFunctionIfStepping(r3, no_reg, dummy, dummy);
// Load context from the function.
__ LoadP(cp, FieldMemOperand(r3, JSFunction::kContextOffset));
// Clear new.target as a safety measure.
__ LoadRoot(r5, Heap::kUndefinedValueRootIndex);
// Get function code.
__ LoadP(ip, FieldMemOperand(r3, JSFunction::kSharedFunctionInfoOffset));
__ LoadP(ip, FieldMemOperand(ip, SharedFunctionInfo::kCodeOffset));
__ AddP(ip, Operand(Code::kHeaderSize - kHeapObjectTag));
// Re-run JSFunction, r3 is function, cp is context.
__ Jump(ip);
}
const bool LiveEdit::kFrameDropperSupported = true;
#undef __
} // namespace internal
} // namespace v8
#endif // V8_TARGET_ARCH_S390
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