Tighten up assertions checking GC-safety of stub calls.

src/code-stubs.h

 // Copyright 2011 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 126 matching lines @@
 
   // Gets the major key from a code object that is a code stub or binary op IC.
   static Major GetMajorKey(Code* code_stub) {
     return static_cast<Major>(code_stub->major_key());
   }
 
   static const char* MajorName(Major major_key, bool allow_unknown_keys);
 
   virtual ~CodeStub() {}
 
+  bool CompilingCallsToThisStubIsGCSafe() {
+    bool is_pregenerated = IsPregenerated();
+#ifdef DEBUG
+    Code* code = NULL;
+    ASSERT(!is_pregenerated || FindCodeInCache(&code));
+#endif
+    return is_pregenerated;
+  }
+
   // See comment above, where Instanceof is defined.
-  virtual bool CompilingCallsToThisStubIsGCSafe() {
+  virtual bool IsPregenerated() {
     return MajorKey() <= Instanceof;
   }
 
   static void GenerateStubsAheadOfTime();
   static void GenerateFPStubs();
 
   // Some stubs put untagged junk on the stack that cannot be scanned by the
   // GC.  This means that we must be statically sure that no GC can occur while
   // they are running.  If that is the case they should override this to return
   // true, which will cause an assertion if we try to call something that can
@@ skipping 398 matching lines @@
   explicit CEntryStub(int result_size,
                       SaveFPRegsMode save_doubles = kDontSaveFPRegs)
       : result_size_(result_size), save_doubles_(save_doubles) { }
 
   void Generate(MacroAssembler* masm);
 
   // The version of this stub that doesn't save doubles is generated ahead of
   // time, so it's OK to call it from other stubs that can't cope with GC during
   // their code generation.  On machines that always have gp registers (x64) we
   // can generate both variants ahead of time.
-  virtual bool CompilingCallsToThisStubIsGCSafe();
+  virtual bool IsPregenerated();
 
  private:
   void GenerateCore(MacroAssembler* masm,
                     Label* throw_normal_exception,
                     Label* throw_termination_exception,
                     Label* throw_out_of_memory_exception,
                     bool do_gc,
                     bool always_allocate_scope);
   void GenerateThrowTOS(MacroAssembler* masm);
   void GenerateThrowUncatchable(MacroAssembler* masm,
@@ skipping 401 matching lines @@
                     bool result);
   void GenerateTypeTransition(MacroAssembler* masm);
 
   Register tos_;
   Types types_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_CODE_STUBS_H_