Add asserts to ensure that we:

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 55 matching lines @@
   V(CounterOp)                           \
   V(ArgumentsAccess)                     \
   V(RegExpExec)                          \
   V(RegExpConstructResult)               \
   V(NumberToString)                      \
   V(CEntry)                              \
   V(JSEntry)                             \
   V(KeyedLoadElement)                    \
   V(KeyedStoreElement)                   \
   V(DebuggerStatement)                   \
-  V(StringDictionaryNegativeLookup)
+  V(StringDictionaryLookup)
 
 // List of code stubs only used on ARM platforms.
 #ifdef V8_TARGET_ARCH_ARM
 #define CODE_STUB_LIST_ARM(V)  \
   V(GetProperty)               \
   V(SetProperty)               \
   V(InvokeBuiltin)             \
   V(RegExpCEntry)              \
   V(DirectCEntry)
 #else
@@ skipping 48 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() {}
 
+  // See comment above, where Instanceof is defined.
+  virtual bool CompilingCallsToThisStubIsGCSafe() {
+    return MajorKey() <= Instanceof;
+  }
+
+  // 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
+  // GC or if we try to put a stack frame on top of the junk, which would not
+  // result in a traversable stack.
+  virtual bool SometimesSetsUpAFrame() { return true; }
+
  protected:
   static const int kMajorBits = 6;
   static const int kMinorBits = kBitsPerInt - kSmiTagSize - kMajorBits;
 
  private:
   // Lookup the code in the (possibly custom) cache.
   bool FindCodeInCache(Code** code_out);
 
   // Nonvirtual wrapper around the stub-specific Generate function.  Call
   // this function to set up the macro assembler and generate the code.
@@ skipping 31 matching lines @@
   // a fixed (non-moveable) code object.
   virtual bool NeedsImmovableCode() { return false; }
 
   // Computes the key based on major and minor.
   uint32_t GetKey() {
     ASSERT(static_cast<int>(MajorKey()) < NUMBER_OF_IDS);
     return MinorKeyBits::encode(MinorKey()) |
            MajorKeyBits::encode(MajorKey());
   }
 
-  // See comment above, where Instanceof is defined.
-  bool AllowsStubCalls() { return MajorKey() <= Instanceof; }
-
   class MajorKeyBits: public BitField<uint32_t, 0, kMajorBits> {};
   class MinorKeyBits: public BitField<uint32_t, kMajorBits, kMinorBits> {};
 
   friend class BreakPointIterator;
 };
 
 
 // Helper interface to prepare to/restore after making runtime calls.
 class RuntimeCallHelper {
  public:
@@ skipping 321 matching lines @@
 
 
 class CEntryStub : public CodeStub {
  public:
   explicit CEntryStub(int result_size)
       : result_size_(result_size), save_doubles_(false) { }
 
   void Generate(MacroAssembler* masm);
   void SaveDoubles() { save_doubles_ = true; }
 
+  // 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.
+  virtual bool CompilingCallsToThisStubIsGCSafe() { return !save_doubles_; }
+
  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,
                                 UncatchableExceptionType type);
@@ skipping 377 matching lines @@
   static Types no_types() { return Types(); }
   static Types all_types() { return Types((1 << NUMBER_OF_TYPES) - 1); }
 
   explicit ToBooleanStub(Register tos, Types types = Types())
       : tos_(tos), types_(types) { }
 
   void Generate(MacroAssembler* masm);
   virtual int GetCodeKind() { return Code::TO_BOOLEAN_IC; }
   virtual void PrintName(StringStream* stream);
 
+  virtual bool SometimesSetsUpAFrame() { return false; }
+
  private:
   Major MajorKey() { return ToBoolean; }
   int MinorKey() { return (tos_.code() << NUMBER_OF_TYPES) | types_.ToByte(); }
 
   virtual void FinishCode(Code* code) {
     code->set_to_boolean_state(types_.ToByte());
   }
 
   void CheckOddball(MacroAssembler* masm,
                     Type type,
                     Heap::RootListIndex value,
                     bool result);
   void GenerateTypeTransition(MacroAssembler* masm);
 
   Register tos_;
   Types types_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_CODE_STUBS_H_