[debugger] fix break locations for assignments and return.

src/debug/debug.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/debug/debug.h"
 
 #include "src/api.h"
 #include "src/arguments.h"
 #include "src/bootstrapper.h"
 #include "src/code-stubs.h"
@@ skipping 66 matching lines @@
     return new CodeIterator(debug_info, type);
   }
 }
 
 BreakLocation::Iterator::Iterator(Handle<DebugInfo> debug_info)
     : debug_info_(debug_info),
       break_index_(-1),
       position_(1),
       statement_position_(1) {}
 
+int BreakLocation::Iterator::ReturnPosition() {
+  if (debug_info_->shared()->HasSourceCode()) {
+    return debug_info_->shared()->end_position() -
+           debug_info_->shared()->start_position() - 1;
+  } else {
+    return 0;
+  }
+}
+
 BreakLocation::CodeIterator::CodeIterator(Handle<DebugInfo> debug_info,
                                           BreakLocatorType type)
     : Iterator(debug_info),
       reloc_iterator_(debug_info->abstract_code()->GetCode(),
                       GetModeMask(type)) {
   if (!Done()) Next();
 }
 
 int BreakLocation::CodeIterator::GetModeMask(BreakLocatorType type) {
   int mask = 0;
@@ skipping 33 matching lines @@
       DCHECK(position_ >= 0);
       DCHECK(statement_position_ >= 0);
       continue;
     }
 
     DCHECK(RelocInfo::IsDebugBreakSlot(rmode()) ||
            RelocInfo::IsDebuggerStatement(rmode()));
 
     if (RelocInfo::IsDebugBreakSlotAtReturn(rmode())) {
       // Set the positions to the end of the function.
-      if (debug_info_->shared()->HasSourceCode()) {
-        position_ = debug_info_->shared()->end_position() -
-                    debug_info_->shared()->start_position() - 1;
-      } else {
-        position_ = 0;
-      }
-      statement_position_ = position_;
+      statement_position_ = position_ = ReturnPosition();
     }
 
     break;
   }
   break_index_++;
 }
 
 BreakLocation BreakLocation::CodeIterator::GetBreakLocation() {
   DebugBreakType type;
   if (RelocInfo::IsDebugBreakSlotAtReturn(rmode())) {
@@ skipping 37 matching lines @@
     DCHECK(position_ >= 0);
     DCHECK(statement_position_ >= 0);
     break_index_++;
 
     enum DebugBreakType type = GetDebugBreakType();
     if (type == NOT_DEBUG_BREAK) continue;
 
     if (break_locator_type_ == ALL_BREAK_LOCATIONS) break;
 
     DCHECK_EQ(CALLS_AND_RETURNS, break_locator_type_);
-    if (type == DEBUG_BREAK_SLOT_AT_CALL ||
-        type == DEBUG_BREAK_SLOT_AT_RETURN) {
+    if (type == DEBUG_BREAK_SLOT_AT_CALL) break;
+    if (type == DEBUG_BREAK_SLOT_AT_RETURN) {
+      DCHECK_EQ(ReturnPosition(), position_);
+      DCHECK_EQ(ReturnPosition(), statement_position_);
       break;
     }
   }
 }
 
 BreakLocation::DebugBreakType
 BreakLocation::BytecodeArrayIterator::GetDebugBreakType() {
   BytecodeArray* bytecode_array = debug_info_->original_bytecode_array();
   interpreter::Bytecode bytecode =
       interpreter::Bytecodes::FromByte(bytecode_array->get(code_offset()));
@@ skipping 2443 matching lines @@
 }
 
 
 void LockingCommandMessageQueue::Clear() {
   base::LockGuard<base::Mutex> lock_guard(&mutex_);
   queue_.Clear();
 }
 
 }  // namespace internal
 }  // namespace v8