Ensures that GDB prints stacktraces correctly for x64 builds when debugging t...

src/code-stubs.cc

 // Copyright 2006-2008 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 91 matching lines @@
 
     // Copy the generated code into a heap object.
     Code::Flags flags = Code::ComputeFlags(
         static_cast<Code::Kind>(GetCodeKind()),
         InLoop(),
         GetICState());
     Handle<Code> new_object = Factory::NewCode(desc, flags, masm.CodeObject());
     RecordCodeGeneration(*new_object, &masm);
     FinishCode(*new_object);
 
+    {

[Vyacheslav Egorov (Chromium), 2011/01/25 12:50:11]

Do we really need this piece of code? 

The code stub will be later registered as GDBJITInterface::CodeTag::STUB so at
the time of registration we will be able to say that this is STUB and handle
it's unwinding information accordingly.

+      ZoneScope uinfo(DELETE_ON_EXIT);
+      uintptr_t begin = reinterpret_cast<uintptr_t>
+                        (new_object->instruction_start());
+      uintptr_t size = new_object->instruction_size();
+
+      // This is to prevent compiler errors about begin and end not being
+      // used when SET_UNWIND_INFO_STUB is empty.
+
+      (void) begin;
+      (void) size;
+      SET_UNWIND_INFO_STUB(begin, size);
+    }
+
     // Update the dictionary and the root in Heap.
     Handle<NumberDictionary> dict =
         Factory::DictionaryAtNumberPut(
             Handle<NumberDictionary>(Heap::code_stubs()),
             GetKey(),
             new_object);
     Heap::public_set_code_stubs(*dict);
 
     code = *new_object;
   }
@@ skipping 103 matching lines @@
   OS::SNPrintF(Vector<char>(name_, kMaxNameLength),
                "InstanceofStub%s%s%s",
                args,
                inline_check,
                return_true_false_object);
   return name_;
 }
 
 
 } }  // namespace v8::internal