Debugger: use debug break slots to break at function exit.

src/arm/assembler-arm-inl.h

Index: src/arm/assembler-arm-inl.h
diff --git a/src/arm/assembler-arm-inl.h b/src/arm/assembler-arm-inl.h
index 4b4e1d32080311da54dabb76e130275c55f53a71..60cda5380be306d00f8d643c88e373b72e569e2b 100644
--- a/src/arm/assembler-arm-inl.h
+++ b/src/arm/assembler-arm-inl.h
@@ -97,7 +97,7 @@ DwVfpRegister DwVfpRegister::FromAllocationIndex(int index) {
 }
 
 
-void RelocInfo::apply(intptr_t delta, ICacheFlushMode icache_flush_mode) {
+void RelocInfo::apply(intptr_t delta) {
   if (RelocInfo::IsInternalReference(rmode_)) {
     // absolute code pointer inside code object moves with the code object.
     int32_t* p = reinterpret_cast<int32_t*>(pc_);
@@ -272,19 +272,18 @@ void RelocInfo::set_code_age_stub(Code* stub,
 }
 
 
-Address RelocInfo::call_address() {
+Address RelocInfo::debug_call_address() {
   // The 2 instructions offset assumes patched debug break slot or return
   // sequence.
-  DCHECK((IsJSReturn(rmode()) && IsPatchedReturnSequence()) ||
-         (IsDebugBreakSlot(rmode()) && IsPatchedDebugBreakSlotSequence()));
-  return Memory::Address_at(pc_ + 2 * Assembler::kInstrSize);
+  DCHECK(IsDebugBreakSlot(rmode()) && IsPatchedDebugBreakSlotSequence());
+  return Memory::Address_at(pc_ + Assembler::kPatchDebugBreakSlotAddressOffset);
 }
 
 
-void RelocInfo::set_call_address(Address target) {
-  DCHECK((IsJSReturn(rmode()) && IsPatchedReturnSequence()) ||
-         (IsDebugBreakSlot(rmode()) && IsPatchedDebugBreakSlotSequence()));
-  Memory::Address_at(pc_ + 2 * Assembler::kInstrSize) = target;
+void RelocInfo::set_debug_call_address(Address target) {
+  DCHECK(IsDebugBreakSlot(rmode()) && IsPatchedDebugBreakSlotSequence());
+  Memory::Address_at(pc_ + Assembler::kPatchDebugBreakSlotAddressOffset) =
+      target;
   if (host() != NULL) {
     Object* target_code = Code::GetCodeFromTargetAddress(target);
     host()->GetHeap()->incremental_marking()->RecordWriteIntoCode(
@@ -293,23 +292,6 @@ void RelocInfo::set_call_address(Address target) {
 }
 
 
-Object* RelocInfo::call_object() {
-  return *call_object_address();
-}
-
-
-void RelocInfo::set_call_object(Object* target) {
-  *call_object_address() = target;
-}
-
-
-Object** RelocInfo::call_object_address() {
-  DCHECK((IsJSReturn(rmode()) && IsPatchedReturnSequence()) ||
-         (IsDebugBreakSlot(rmode()) && IsPatchedDebugBreakSlotSequence()));
-  return reinterpret_cast<Object**>(pc_ + 2 * Assembler::kInstrSize);
-}
-
-
 void RelocInfo::WipeOut() {
   DCHECK(IsEmbeddedObject(rmode_) || IsCodeTarget(rmode_) ||
          IsRuntimeEntry(rmode_) || IsExternalReference(rmode_) ||
@@ -353,10 +335,8 @@ void RelocInfo::Visit(Isolate* isolate, ObjectVisitor* visitor) {
     visitor->VisitInternalReference(this);
   } else if (RelocInfo::IsCodeAgeSequence(mode)) {
     visitor->VisitCodeAgeSequence(this);
-  } else if (((RelocInfo::IsJSReturn(mode) &&
-              IsPatchedReturnSequence()) ||
-             (RelocInfo::IsDebugBreakSlot(mode) &&
-              IsPatchedDebugBreakSlotSequence())) &&
+  } else if (RelocInfo::IsDebugBreakSlot(mode) &&
+             IsPatchedDebugBreakSlotSequence() &&
              isolate->debug()->has_break_points()) {
     visitor->VisitDebugTarget(this);
   } else if (RelocInfo::IsRuntimeEntry(mode)) {
@@ -381,10 +361,8 @@ void RelocInfo::Visit(Heap* heap) {
   } else if (RelocInfo::IsCodeAgeSequence(mode)) {
     StaticVisitor::VisitCodeAgeSequence(heap, this);
   } else if (heap->isolate()->debug()->has_break_points() &&
-             ((RelocInfo::IsJSReturn(mode) &&
-              IsPatchedReturnSequence()) ||
-             (RelocInfo::IsDebugBreakSlot(mode) &&
-              IsPatchedDebugBreakSlotSequence()))) {
+             RelocInfo::IsDebugBreakSlot(mode) &&
+             IsPatchedDebugBreakSlotSequence()) {
     StaticVisitor::VisitDebugTarget(heap, this);
   } else if (RelocInfo::IsRuntimeEntry(mode)) {
     StaticVisitor::VisitRuntimeEntry(this);
@@ -504,11 +482,6 @@ Address Assembler::target_address_from_return_address(Address pc) {
 }
 
 
-Address Assembler::break_address_from_return_address(Address pc) {
-  return pc - Assembler::kPatchDebugBreakSlotReturnOffset;
-}
-
-
 Address Assembler::return_address_from_call_start(Address pc) {
   if (IsLdrPcImmediateOffset(Memory::int32_at(pc)) |
       IsLdrPpImmediateOffset(Memory::int32_at(pc))) {