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

src/ia32/code-stubs-ia32.cc

Index: src/ia32/code-stubs-ia32.cc
diff --git a/src/ia32/code-stubs-ia32.cc b/src/ia32/code-stubs-ia32.cc
index 12cc499a7777797695004ae49938228325fecdd5..ee54bc113b76e02921b81e9d060854bebf084658 100644
--- a/src/ia32/code-stubs-ia32.cc
+++ b/src/ia32/code-stubs-ia32.cc
@@ -4863,6 +4863,27 @@ void CEntryStub::Generate(MacroAssembler* masm) {
   __ 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);
 }