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

src/heap/mark-compact.cc

 // Copyright 2012 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"
 
 #include "src/base/atomicops.h"
 #include "src/base/bits.h"
 #include "src/code-stubs.h"
 #include "src/compilation-cache.h"
@@ skipping 2851 matching lines @@
     DCHECK(RelocInfo::IsCodeAgeSequence(rinfo->rmode()));
     Object* stub = rinfo->code_age_stub();
     DCHECK(stub != NULL);
     VisitPointer(&stub);
     if (stub != rinfo->code_age_stub()) {
       rinfo->set_code_age_stub(Code::cast(stub));
     }
   }
 
   void VisitDebugTarget(RelocInfo* rinfo) {
-    DCHECK((RelocInfo::IsJSReturn(rinfo->rmode()) &&
-            rinfo->IsPatchedReturnSequence()) ||
-           (RelocInfo::IsDebugBreakSlot(rinfo->rmode()) &&
-            rinfo->IsPatchedDebugBreakSlotSequence()));
-    Object* target = Code::GetCodeFromTargetAddress(rinfo->call_address());
+    DCHECK(RelocInfo::IsDebugBreakSlot(rinfo->rmode()) &&
+           rinfo->IsPatchedDebugBreakSlotSequence());
+    Object* target =
+        Code::GetCodeFromTargetAddress(rinfo->debug_call_address());
     VisitPointer(&target);
-    rinfo->set_call_address(Code::cast(target)->instruction_start());
+    rinfo->set_debug_call_address(Code::cast(target)->instruction_start());
   }
 
   static inline void UpdateSlot(Heap* heap, Object** slot) {
     Object* obj = reinterpret_cast<Object*>(
         base::NoBarrier_Load(reinterpret_cast<base::AtomicWord*>(slot)));
 
     if (!obj->IsHeapObject()) return;
 
     HeapObject* heap_obj = HeapObject::cast(obj);
 
@@ skipping 539 matching lines @@
     case SlotsBuffer::RELOCATED_CODE_OBJECT: {
       HeapObject* obj = HeapObject::FromAddress(addr);
       Code::cast(obj)->CodeIterateBody(v);
       break;
     }
     case SlotsBuffer::DEBUG_TARGET_SLOT: {
       RelocInfo rinfo(addr, RelocInfo::DEBUG_BREAK_SLOT_AT_POSITION, 0, NULL);
       if (rinfo.IsPatchedDebugBreakSlotSequence()) rinfo.Visit(isolate, v);
       break;
     }
-    case SlotsBuffer::JS_RETURN_SLOT: {
-      RelocInfo rinfo(addr, RelocInfo::JS_RETURN, 0, NULL);
-      if (rinfo.IsPatchedReturnSequence()) rinfo.Visit(isolate, v);
-      break;
-    }
     case SlotsBuffer::EMBEDDED_OBJECT_SLOT: {
       RelocInfo rinfo(addr, RelocInfo::EMBEDDED_OBJECT, 0, NULL);
       rinfo.Visit(isolate, v);
       break;
     }
     case SlotsBuffer::OBJECT_SLOT: {
       v->VisitPointer(reinterpret_cast<Object**>(addr));
       break;
     }
     default:
@@ skipping 1069 matching lines @@
 
 static inline SlotsBuffer::SlotType SlotTypeForRMode(RelocInfo::Mode rmode) {
   if (RelocInfo::IsCodeTarget(rmode)) {
     return SlotsBuffer::CODE_TARGET_SLOT;
   } else if (RelocInfo::IsCell(rmode)) {
     return SlotsBuffer::CELL_TARGET_SLOT;
   } else if (RelocInfo::IsEmbeddedObject(rmode)) {
     return SlotsBuffer::EMBEDDED_OBJECT_SLOT;
   } else if (RelocInfo::IsDebugBreakSlot(rmode)) {
     return SlotsBuffer::DEBUG_TARGET_SLOT;
-  } else if (RelocInfo::IsJSReturn(rmode)) {
-    return SlotsBuffer::JS_RETURN_SLOT;
   }
   UNREACHABLE();
   return SlotsBuffer::NUMBER_OF_SLOT_TYPES;
 }
 
 
 void MarkCompactCollector::RecordRelocSlot(RelocInfo* rinfo, Object* target) {
   Page* target_page = Page::FromAddress(reinterpret_cast<Address>(target));
   RelocInfo::Mode rmode = rinfo->rmode();
   if (target_page->IsEvacuationCandidate() &&
@@ skipping 109 matching lines @@
   SlotsBuffer* buffer = *buffer_address;
   while (buffer != NULL) {
     SlotsBuffer* next_buffer = buffer->next();
     DeallocateBuffer(buffer);
     buffer = next_buffer;
   }
   *buffer_address = NULL;
 }
 }  // namespace internal
 }  // namespace v8