Refactor BreakLocationIterator.

src/arm64/debug-arm64.cc

 // Copyright 2013 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_ARM64
 
 #include "src/codegen.h"
 #include "src/debug.h"
 
 namespace v8 {
 namespace internal {
 
 
 #define __ ACCESS_MASM(masm)
 
-bool BreakLocationIterator::IsDebugBreakAtReturn() {
-  return Debug::IsDebugBreakAtReturn(rinfo());
-}
 
-
-void BreakLocationIterator::SetDebugBreakAtReturn() {
+void BreakLocation::SetDebugBreakAtReturn() {
   // Patch the code emitted by FullCodeGenerator::EmitReturnSequence, changing
   // the return from JS function sequence from
   //   mov sp, fp
   //   ldp fp, lr, [sp] #16
   //   lrd ip0, [pc, #(3 * kInstructionSize)]
   //   add sp, sp, ip0
   //   ret
   //   <number of paramters ...
   //    ... plus one (64 bits)>
   // to a call to the debug break return code.
   //   ldr ip0, [pc, #(3 * kInstructionSize)]
   //   blr ip0
   //   hlt kHltBadCode    @ code should not return, catch if it does.
   //   <debug break return code ...
   //    ... entry point address (64 bits)>
 
   // The patching code must not overflow the space occupied by the return
   // sequence.
-  STATIC_ASSERT(Assembler::kJSRetSequenceInstructions >= 5);
-  PatchingAssembler patcher(reinterpret_cast<Instruction*>(rinfo()->pc()), 5);
+  STATIC_ASSERT(Assembler::kJSReturnSequenceInstructions >= 5);
+  PatchingAssembler patcher(reinterpret_cast<Instruction*>(pc()), 5);
   byte* entry =
       debug_info_->GetIsolate()->builtins()->Return_DebugBreak()->entry();
 
   // The first instruction of a patched return sequence must be a load literal
   // loading the address of the debug break return code.
   patcher.ldr_pcrel(ip0, (3 * kInstructionSize) >> kLoadLiteralScaleLog2);
   // TODO(all): check the following is correct.
   // The debug break return code will push a frame and call statically compiled
   // code. By using blr, even though control will not return after the branch,
   // this call site will be registered in the frame (lr being saved as the pc
   // of the next instruction to execute for this frame). The debugger can now
   // iterate on the frames to find call to debug break return code.
   patcher.blr(ip0);
   patcher.hlt(kHltBadCode);
   patcher.dc64(reinterpret_cast<int64_t>(entry));
 }
 
 
-void BreakLocationIterator::ClearDebugBreakAtReturn() {
-  // Reset the code emitted by EmitReturnSequence to its original state.
-  rinfo()->PatchCode(original_rinfo()->pc(),
-                     Assembler::kJSRetSequenceInstructions);
-}
-
-
-bool Debug::IsDebugBreakAtReturn(RelocInfo* rinfo) {
-  DCHECK(RelocInfo::IsJSReturn(rinfo->rmode()));
-  return rinfo->IsPatchedReturnSequence();
-}
-
-
-bool BreakLocationIterator::IsDebugBreakAtSlot() {
-  DCHECK(IsDebugBreakSlot());
-  // Check whether the debug break slot instructions have been patched.
-  return rinfo()->IsPatchedDebugBreakSlotSequence();
-}
-
-
-void BreakLocationIterator::SetDebugBreakAtSlot() {
+void BreakLocation::SetDebugBreakAtSlot() {
   // Patch the code emitted by DebugCodegen::GenerateSlots, changing the debug
   // break slot code from
   //   mov x0, x0    @ nop DEBUG_BREAK_NOP
   //   mov x0, x0    @ nop DEBUG_BREAK_NOP
   //   mov x0, x0    @ nop DEBUG_BREAK_NOP
   //   mov x0, x0    @ nop DEBUG_BREAK_NOP
   // to a call to the debug slot code.
   //   ldr ip0, [pc, #(2 * kInstructionSize)]
   //   blr ip0
   //   <debug break slot code ...
   //    ... entry point address (64 bits)>
 
   // TODO(all): consider adding a hlt instruction after the blr as we don't
   // expect control to return here. This implies increasing
   // kDebugBreakSlotInstructions to 5 instructions.
 
   // The patching code must not overflow the space occupied by the return
   // sequence.
   STATIC_ASSERT(Assembler::kDebugBreakSlotInstructions >= 4);
-  PatchingAssembler patcher(reinterpret_cast<Instruction*>(rinfo()->pc()), 4);
+  PatchingAssembler patcher(reinterpret_cast<Instruction*>(pc()), 4);
   byte* entry =
       debug_info_->GetIsolate()->builtins()->Slot_DebugBreak()->entry();
 
   // The first instruction of a patched debug break slot must be a load literal
   // loading the address of the debug break slot code.
   patcher.ldr_pcrel(ip0, (2 * kInstructionSize) >> kLoadLiteralScaleLog2);
   // TODO(all): check the following is correct.
   // The debug break slot code will push a frame and call statically compiled
   // code. By using blr, event hough control will not return after the branch,
   // this call site will be registered in the frame (lr being saved as the pc
   // of the next instruction to execute for this frame). The debugger can now
   // iterate on the frames to find call to debug break slot code.
   patcher.blr(ip0);
   patcher.dc64(reinterpret_cast<int64_t>(entry));
 }
 
 
-void BreakLocationIterator::ClearDebugBreakAtSlot() {
-  DCHECK(IsDebugBreakSlot());
-  rinfo()->PatchCode(original_rinfo()->pc(),
-                     Assembler::kDebugBreakSlotInstructions);
-}
-
-
 static void Generate_DebugBreakCallHelper(MacroAssembler* masm,
                                           RegList object_regs,
                                           RegList non_object_regs,
                                           Register scratch) {
   {
     FrameScope scope(masm, StackFrame::INTERNAL);
 
     // Load padding words on stack.
     __ Mov(scratch, Smi::FromInt(LiveEdit::kFramePaddingValue));
     __ PushMultipleTimes(scratch, LiveEdit::kFramePaddingInitialSize);
@@ skipping 236 matching lines @@
   // Re-run JSFunction, x1 is function, cp is context.
   __ Br(scratch);
 }
 
 
 const bool LiveEdit::kFrameDropperSupported = true;
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM64