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

src/codegen.cc

 // Copyright 2010 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 232 matching lines @@
   }
   if (FLAG_trace_codegen) {
     PrintF("Classic Compiler - ");
   }
   MakeCodePrologue(info);
   // Generate code.
   const int kInitialBufferSize = 4 * KB;
   MacroAssembler masm(NULL, kInitialBufferSize);
 #ifdef ENABLE_GDB_JIT_INTERFACE
   masm.positions_recorder()->StartGDBJITLineInfoRecording();
+#ifdef V8_TARGET_ARCH_X64

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

Revert this change.

I am considering disabling GDBJIT support in classic codegen completely. 

+  UnwindInfoInterface dummy;
+#endif
 #endif
   CodeGenerator cgen(&masm);
   CodeGeneratorScope scope(&cgen);
   cgen.Generate(info);
   if (cgen.HasStackOverflow()) {
     ASSERT(!Top::has_pending_exception());
     return false;
   }
 
   InLoopFlag in_loop = info->is_in_loop() ? IN_LOOP : NOT_IN_LOOP;
   Code::Flags flags = Code::ComputeFlags(Code::FUNCTION, in_loop);
   Handle<Code> code = MakeCodeEpilogue(cgen.masm(), flags, info);
+
+  SET_UNWIND_INFO_START_ADDRESS(reinterpret_cast<uintptr_t>
+                                (code->instruction_start()));
+
   // There is no stack check table in code generated by the classic backend.
   code->SetNoStackCheckTable();
   CodeGenerator::PrintCode(code, info);
   info->SetCode(code);  // May be an empty handle.
 #ifdef ENABLE_GDB_JIT_INTERFACE
   if (FLAG_gdbjit && !code.is_null()) {
     GDBJITLineInfo* lineinfo =
         masm.positions_recorder()->DetachGDBJITLineInfo();
 
     GDBJIT(RegisterDetailedLineInfo(*code, lineinfo));
@@ skipping 212 matching lines @@
   int result = save_doubles_ ? 1 : 0;
 #ifdef _WIN64
   return result | ((result_size_ == 1) ? 0 : 2);
 #else
   return result;
 #endif
 }
 
 
 } }  // namespace v8::internal