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

src/builtins.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 1476 matching lines @@
           }
         }
       }
       // Log the event and add the code to the builtins array.
       PROFILE(CodeCreateEvent(Logger::BUILTIN_TAG,
                               Code::cast(code),
                               functions[i].s_name));
       GDBJIT(AddCode(GDBJITInterface::BUILTIN,
                      functions[i].s_name,
                      Code::cast(code)));
+      {
+        ZoneScope uinfo(DELETE_ON_EXIT);

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

Do we really need this piece of code?

The code stub was registered above as GDBJITInterface::CodeTag::BUILTIN so
GDBJIT really knows how to handle it.

+        uintptr_t begin = reinterpret_cast<uintptr_t>
+                          (Code::cast(code)->instruction_start());
+        uintptr_t size = Code::cast(code)->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);
+      }
+
       builtins_[i] = code;
 #ifdef ENABLE_DISASSEMBLER
       if (FLAG_print_builtin_code) {
         PrintF("Builtin: %s\n", functions[i].s_name);
         Code::cast(code)->Disassemble(functions[i].s_name);
         PrintF("\n");
       }
 #endif
     } else {
       // Deserializing. The values will be filled in during IterateBuiltins.
@@ skipping 24 matching lines @@
       if (entry->contains(pc)) {
         return names_[i];
       }
     }
   }
   return NULL;
 }
 
 
 } }  // namespace v8::internal