Fix Debug::Break crash.

src/debug.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 874 matching lines @@
   Debug::set_interrupts_pending(PREEMPT);
 }
 
 
 void Debug::Iterate(ObjectVisitor* v) {
   v->VisitPointer(BitCast<Object**>(&(debug_break_return_)));
   v->VisitPointer(BitCast<Object**>(&(debug_break_slot_)));
 }
 
 
-// TODO(131642): Remove this when fixed.
-void Debug::PutValuesOnStackAndDie(int start,
-                                   Address c_entry_fp,
-                                   Address last_fp,
-                                   Address larger_fp,
-                                   int count,
-                                   char* stack,
-                                   int end) {
-  OS::PrintError("start:       %d\n", start);
-  OS::PrintError("c_entry_fp:  %p\n", static_cast<void*>(c_entry_fp));
-  OS::PrintError("last_fp:     %p\n", static_cast<void*>(last_fp));
-  OS::PrintError("larger_fp:   %p\n", static_cast<void*>(larger_fp));
-  OS::PrintError("count:       %d\n", count);
-  if (stack != NULL) {
-    OS::PrintError("stack:       %s\n", stack);
-  }
-  OS::PrintError("end:         %d\n", end);
-  OS::Abort();
-}
-
-
 Object* Debug::Break(Arguments args) {
   Heap* heap = isolate_->heap();
   HandleScope scope(isolate_);
   ASSERT(args.length() == 0);
 
   thread_local_.frame_drop_mode_ = FRAMES_UNTOUCHED;
 
   // Get the top-most JavaScript frame.
   JavaScriptFrameIterator it(isolate_);
   JavaScriptFrame* frame = it.frame();
@@ skipping 77 matching lines @@
     // and keep step count queued up in the meantime.
     if (step_action == StepNext && frame->fp() < thread_local_.last_fp_) {
       // Count frames until target frame
       int count = 0;
       JavaScriptFrameIterator it(isolate_);
       while (!it.done() && it.frame()->fp() < thread_local_.last_fp_) {
         count++;
         it.Advance();
       }
 
-      // TODO(131642): Remove this when fixed.
-      // Catch the cases that would lead to crashes and capture
-      // - C entry FP at which to start stack crawl.
-      // - FP of the frame at which we plan to stop stepping out (last FP).
-      // - current FP that's larger than last FP.
-      // - Counter for the number of steps to step out.
-      // - stack trace string.
-      if (it.done()) {
-        // We crawled the entire stack, never reaching last_fp_.
-        Handle<String> stack = isolate_->StackTraceString();
-        char buffer[8192];
-        int length = Min(8192, stack->length());
-        String::WriteToFlat(*stack, buffer, 0, length - 1);
-        PutValuesOnStackAndDie(0xBEEEEEEE,
-                               frame->fp(),
-                               thread_local_.last_fp_,
-                               reinterpret_cast<Address>(0xDEADDEAD),
-                               count,
-                               buffer,
-                               0xCEEEEEEE);
-      } else if (it.frame()->fp() != thread_local_.last_fp_) {
-        // We crawled over last_fp_, without getting a match.
-        Handle<String> stack = isolate_->StackTraceString();
-        char buffer[8192];
-        int length = Min(8192, stack->length());
-        String::WriteToFlat(*stack, buffer, 0, length - 1);
-        PutValuesOnStackAndDie(0xDEEEEEEE,
-                               frame->fp(),
-                               thread_local_.last_fp_,
-                               it.frame()->fp(),
-                               count,
-                               buffer,
-                               0xFEEEEEEE);
+      // Check that we indeed found the frame we are looking for.
+      CHECK(!it.done() && (it.frame()->fp() == thread_local_.last_fp_));
+      if (step_count > 1) {
+        // Save old count and action to continue stepping after StepOut.
+        thread_local_.queued_step_count_ = step_count - 1;
       }
 
-      // If we found original frame
-      if (it.frame()->fp() == thread_local_.last_fp_) {
-        if (step_count > 1) {
-          // Save old count and action to continue stepping after
-          // StepOut
-          thread_local_.queued_step_count_ = step_count - 1;
-        }
-
-        // Set up for StepOut to reach target frame
-        step_action = StepOut;
-        step_count = count;
-      }
+      // Set up for StepOut to reach target frame.
+      step_action = StepOut;
+      step_count = count;
     }
 
     // Clear all current stepping setup.
     ClearStepping();
 
     // Set up for the remaining steps.
     PrepareStep(step_action, step_count);
   }
 
   if (thread_local_.frame_drop_mode_ == FRAMES_UNTOUCHED) {
@@ skipping 2641 matching lines @@
     {
       Locker locker;
       Isolate::Current()->debugger()->CallMessageDispatchHandler();
     }
   }
 }
 
 #endif  // ENABLE_DEBUGGER_SUPPORT
 
 } }  // namespace v8::internal