Tighten up assertions checking GC-safety of stub calls.

src/arm/code-stubs-arm.cc

 // 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 841 matching lines @@
   } else {
     __ Strd(r0, r1, FieldMemOperand(heap_number_result,
                                     HeapNumber::kValueOffset));
   }
   // Place heap_number_result in r0 and return to the pushed return address.
   __ mov(r0, Operand(heap_number_result));
   __ pop(pc);
 }
 
 
-bool WriteInt32ToHeapNumberStub::CompilingCallsToThisStubIsGCSafe() {
+bool WriteInt32ToHeapNumberStub::IsPregenerated() {
   // These variants are compiled ahead of time.  See next method.
   if (the_int_.is(r1) && the_heap_number_.is(r0) && scratch_.is(r2)) {
     return true;
   }
   if (the_int_.is(r2) && the_heap_number_.is(r0) && scratch_.is(r3)) {
     return true;
   }
   // Other register combinations are generated as and when they are needed,
   // so it is unsafe to call them from stubs (we can't generate a stub while
   // we are generating a stub).
@@ skipping 1214 matching lines @@
 }
 
 
 void BinaryOpStub::GenerateTypeTransitionWithSavedArgs(
     MacroAssembler* masm) {
   UNIMPLEMENTED();
 }
 
 
 void BinaryOpStub::Generate(MacroAssembler* masm) {
+  // Explicitly allow generation of nested stubs. It is safe here.

[Erik Corry, 2011/09/26 22:47:26]

Can the comment explain in more detail why this is OK?

+  AllowStubCallsScope allow_stub_calls(masm, true);
+
   switch (operands_type_) {
     case BinaryOpIC::UNINITIALIZED:
       GenerateTypeTransition(masm);
       break;
     case BinaryOpIC::SMI:
       GenerateSmiStub(masm);
       break;
     case BinaryOpIC::INT32:
       GenerateInt32Stub(masm);
       break;
@@ skipping 1280 matching lines @@
   __ bind(&call_runtime);
   __ TailCallRuntime(Runtime::kMath_pow_cfunction, 2, 1);
 }
 
 
 bool CEntryStub::NeedsImmovableCode() {
   return true;
 }
 
 
-bool CEntryStub::CompilingCallsToThisStubIsGCSafe() {
+bool CEntryStub::IsPregenerated() {
   return (!save_doubles_ || ISOLATE->fp_stubs_generated()) &&
           result_size_ == 1;
 }
 
 
 void CodeStub::GenerateStubsAheadOfTime() {
   WriteInt32ToHeapNumberStub::GenerateFixedRegStubsAheadOfTime();
+  StoreBufferOverflowStub::GenerateFixedRegStubsAheadOfTime();
+  RecordWriteStub::GenerateFixedRegStubsAheadOfTime();
 }
 
 
 void CodeStub::GenerateFPStubs() {
   CEntryStub save_doubles(1, kSaveFPRegs);
   Handle<Code> code = save_doubles.GetCode();
   code->GetIsolate()->set_fp_stubs_generated(true);
 }
 
 
@@ skipping 3415 matching lines @@
   // Used in KeyedStoreStubCompiler::CompileStoreField via GenerateStoreField.
   { r2, r1, r3, EMIT_REMEMBERED_SET },
   { r3, r1, r2, EMIT_REMEMBERED_SET },
   // KeyedStoreStubCompiler::GenerateStoreFastElement.
   { r4, r2, r3, EMIT_REMEMBERED_SET },
   // Null termination.
   { no_reg, no_reg, no_reg, EMIT_REMEMBERED_SET}
 };
 
 
-bool RecordWriteStub::CompilingCallsToThisStubIsGCSafe() {
+bool RecordWriteStub::IsPregenerated() {
   for (AheadOfTimeWriteBarrierStubList* entry = kAheadOfTime;
        !entry->object.is(no_reg);
        entry++) {
     if (object_.is(entry->object) &&
         value_.is(entry->value) &&
         address_.is(entry->address) &&
         remembered_set_action_ == entry->action &&
         save_fp_regs_mode_ == kDontSaveFPRegs) {
       return true;
     }
@@ skipping 213 matching lines @@
 
   // Fall through when we need to inform the incremental marker.
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM