Patch CEntry stub to swallow exception if liveedit/restart frame needs it.

src/ia32/code-stubs-ia32.cc

 // Copyright 2012 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
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 //       disclaimer in the documentation and/or other materials provided
@@ skipping 4845 matching lines @@
   JumpIfOOM(masm, eax, ecx, &already_have_failure);
   __ mov(eax, reinterpret_cast<int32_t>(Failure::OutOfMemoryException(0x1)));
   __ bind(&already_have_failure);
   __ mov(Operand::StaticVariable(pending_exception), eax);
   // Fall through to the next label.
 
   __ bind(&throw_termination_exception);
   __ ThrowUncatchable(eax);
 
   __ bind(&throw_normal_exception);
+
+#ifdef ENABLE_DEBUGGER_SUPPORT
+  Label proceed_throwing;
+  ExternalReference c_entry_frame_to_ignore_exception =
+      ExternalReference(Debug_Address::CEntryFrameToIgnoreException(),
+          masm->isolate());
+
+  __ xor_(ecx, ecx);
+  __ mov(edx, Operand::StaticVariable(c_entry_frame_to_ignore_exception));
+  __ mov(Operand::StaticVariable(c_entry_frame_to_ignore_exception), ecx);
+
+  __ cmp(ebp, edx);

[Yang, 2013/09/13 09:47:56]

Instead of these 4 instructions, you could just

__ cmp(ebp, Operand::StaticVariable(c_entry_frame_to_ignore_exception));
__ mov(Operand::StaticVariable(c_entry_frame_to_ignore_exception),
Immediate(0));

I don't think mov sets any flags, so you can do the conditional jump afterwards
based on the results of cmp.

[Peter.Rybin, 2013/09/19 15:35:31]

Thanks a lot.
I also moved "clear" statement below the jump, because not matching frames
obviously mustn't clear this pointer.

+
+  __ j(not_equal, &proceed_throwing, Label::kNear);
+
+  __ LeaveExitFrame(save_doubles_ == kSaveFPRegs);
+  __ ret(0);
+
+  __ bind(&proceed_throwing);
+#endif  // ENABLE_DEBUGGER_SUPPORT
+
   __ Throw(eax);
 }
 
 
 void JSEntryStub::GenerateBody(MacroAssembler* masm, bool is_construct) {
   Label invoke, handler_entry, exit;
   Label not_outermost_js, not_outermost_js_2;
 
   ProfileEntryHookStub::MaybeCallEntryHook(masm);
 
@@ skipping 2838 matching lines @@
   __ bind(&fast_elements_case);
   GenerateCase(masm, FAST_ELEMENTS);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32