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

src/x64/assembler-x64-inl.h

Index: src/x64/assembler-x64-inl.h
diff --git a/src/x64/assembler-x64-inl.h b/src/x64/assembler-x64-inl.h
index 90deaba4fee64aacbae7ede13decf38ecb268811..1495a5ce78a95e06387f051571eba8171029e672 100644
--- a/src/x64/assembler-x64-inl.h
+++ b/src/x64/assembler-x64-inl.h
@@ -293,11 +293,6 @@ Address Assembler::target_address_from_return_address(Address pc) {
 }
 
 
-Address Assembler::break_address_from_return_address(Address pc) {
-  return pc - Assembler::kPatchDebugBreakSlotReturnOffset;
-}
-
-
 Handle<Object> Assembler::code_target_object_handle_at(Address pc) {
   return code_targets_[Memory::int32_at(pc)];
 }
@@ -311,21 +306,17 @@ Address Assembler::runtime_entry_at(Address pc) {
 // Implementation of RelocInfo
 
 // The modes possibly affected by apply must be in kApplyMask.
-void RelocInfo::apply(intptr_t delta, ICacheFlushMode icache_flush_mode) {
-  bool flush_icache = icache_flush_mode != SKIP_ICACHE_FLUSH;
-  if (IsInternalReference(rmode_)) {
-    // absolute code pointer inside code object moves with the code object.
-    Memory::Address_at(pc_) += delta;
-    if (flush_icache) CpuFeatures::FlushICache(pc_, sizeof(Address));
-  } else if (IsCodeTarget(rmode_) || IsRuntimeEntry(rmode_)) {
+void RelocInfo::apply(intptr_t delta) {
+  if (IsCodeTarget(rmode_) || IsRuntimeEntry(rmode_)) {
     Memory::int32_at(pc_) -= static_cast<int32_t>(delta);
-    if (flush_icache) CpuFeatures::FlushICache(pc_, sizeof(int32_t));
-  } else if (rmode_ == CODE_AGE_SEQUENCE) {
+  } else if (IsCodeAgeSequence(rmode_)) {
     if (*pc_ == kCallOpcode) {
       int32_t* p = reinterpret_cast<int32_t*>(pc_ + 1);
       *p -= static_cast<int32_t>(delta);  // Relocate entry.
-      if (flush_icache) CpuFeatures::FlushICache(p, sizeof(uint32_t));
     }
+  } else if (IsInternalReference(rmode_)) {
+    // absolute code pointer inside code object moves with the code object.
+    Memory::Address_at(pc_) += delta;
   }
 }
 
@@ -526,21 +517,18 @@ void RelocInfo::set_code_age_stub(Code* stub,
 }
 
 
-Address RelocInfo::call_address() {
-  DCHECK((IsJSReturn(rmode()) && IsPatchedReturnSequence()) ||
-         (IsDebugBreakSlot(rmode()) && IsPatchedDebugBreakSlotSequence()));
-  return Memory::Address_at(
-      pc_ + Assembler::kRealPatchReturnSequenceAddressOffset);
+Address RelocInfo::debug_call_address() {
+  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_ + Assembler::kRealPatchReturnSequenceAddressOffset) =
+void RelocInfo::set_debug_call_address(Address target) {
+  DCHECK(IsDebugBreakSlot(rmode()) && IsPatchedDebugBreakSlotSequence());
+  Memory::Address_at(pc_ + Assembler::kPatchDebugBreakSlotAddressOffset) =
       target;
-  CpuFeatures::FlushICache(
-      pc_ + Assembler::kRealPatchReturnSequenceAddressOffset, sizeof(Address));
+  CpuFeatures::FlushICache(pc_ + Assembler::kPatchDebugBreakSlotAddressOffset,
+                           sizeof(Address));
   if (host() != NULL) {
     Object* target_code = Code::GetCodeFromTargetAddress(target);
     host()->GetHeap()->incremental_marking()->RecordWriteIntoCode(
@@ -549,24 +537,6 @@ 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_ + Assembler::kPatchReturnSequenceAddressOffset);
-}
-
-
 void RelocInfo::Visit(Isolate* isolate, ObjectVisitor* visitor) {
   RelocInfo::Mode mode = rmode();
   if (mode == RelocInfo::EMBEDDED_OBJECT) {
@@ -582,10 +552,8 @@ 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)) {
@@ -611,10 +579,8 @@ 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);