Bug 122982

Created attachment 214538 [details] Patch This patch also fixes https://bugs.webkit.org/show_bug.cgi?id=122980 by eliminating the problem.

*** Bug 122980 has been marked as a duplicate of this bug. ***

Comment on attachment 214538 [details] Patch View in context: https://bugs.webkit.org/attachment.cgi?id=214538&action=review r=me > Source/JavaScriptCore/dfg/DFGJITCompiler.cpp:155 > + // lookupExceptionHandler leaves the handler CallFrame* in vm->callFrameForThrow, > + // and the address of the handler in vm->targetMachinePCForThrow. > + move(TrustedImmPtr(m_vm), GPRInfo::regT0); > + loadPtr(Address(GPRInfo::regT0, VM::targetMachinePCForThrowOffset()), GPRInfo::regT1); > + loadPtr(Address(GPRInfo::regT0, VM::callFrameForThrowOffset()), GPRInfo::regT0); > + jump(GPRInfo::regT1); Can you put this in a helper function? > Source/JavaScriptCore/jit/JITOpcodes32_64.cpp:195 > + // operationVMHandleException leaves the handler CallFrame* in vm->callFrameForThrow, > + // and the address of the handler in vm->targetMachinePCForThrow. > + move(TrustedImmPtr(vm), regT0); > + loadPtr(Address(regT0, VM::targetMachinePCForThrowOffset()), regT1); > + loadPtr(Address(regT0, VM::callFrameForThrowOffset()), regT0); > jump(regT1); Can you put this in a helper function? (It should be the same on 32-bit: loadPtr in both cases.) > Source/JavaScriptCore/jit/JITOperations.cpp:1642 > +void JIT_OPERATION operationVMHandleException(ExecState* exec, VM* vm) Why do we need the VM* argument? Let's remove it, to simplify callers. > Source/JavaScriptCore/jit/JITOperations.cpp:1654 > + vm->topCallFrame = exec; We don't need this. NativeCallFrameTracer takes care of this for us. > Source/JavaScriptCore/runtime/VM.h:352 > + static ptrdiff_t callFrameForThrowOffset() > + { > + return OBJECT_OFFSETOF(VM, callFrameForThrow); > + } > + > + static ptrdiff_t targetMachinePCForThrowOffset() > + { > + return OBJECT_OFFSETOF(VM, targetMachinePCForThrow); > + } Interesting: Looks like we were doing this already -- just inconsistently.

Comment on attachment 214538 [details] Patch Attachment 214538 [details] did not pass win-ews (win): Output: http://webkit-queues.appspot.com/results/4578002

Delete "EXTERN cti_vm_handle_exception : near" in JITStubsMSVC64.asm and the MSVC ctiVMHandleException implementation in JITStubsX86.h and this compiles successfully. It runs the tests successfully on Win32 but not on Win64.

(In reply to comment #3) > (From update of attachment 214538 [details]) > View in context: https://bugs.webkit.org/attachment.cgi?id=214538&action=review > > r=me > > > Source/JavaScriptCore/jit/JITOperations.cpp:1642 > > +void JIT_OPERATION operationVMHandleException(ExecState* exec, VM* vm) > > Why do we need the VM* argument? Let's remove it, to simplify callers. The original code for cti_vm_handle_exception handled the case where callFrame is null. That version was returning a struct with the catch callFrame/PC. Given that we are now using the VM to pass back those values, we need a VM even if we don't have a callFrame. That's why I passed it in as an argument. Saying that, I have instrumented the code and it doesn't appear that we ever exercise that path. Unless we can come up with a scenario where we need to unwind and exception and won't have a valid callFrame, I'll remove the VM argument and corresponding code. > > Source/JavaScriptCore/jit/JITOperations.cpp:1654 > > + vm->topCallFrame = exec; > > We don't need this. NativeCallFrameTracer takes care of this for us. I'll remove. > > Source/JavaScriptCore/runtime/VM.h:352 > > + static ptrdiff_t callFrameForThrowOffset() > > + { > > + return OBJECT_OFFSETOF(VM, callFrameForThrow); > > + } > > + > > + static ptrdiff_t targetMachinePCForThrowOffset() > > + { > > + return OBJECT_OFFSETOF(VM, targetMachinePCForThrow); > > + } > > Interesting: Looks like we were doing this already -- just inconsistently. It appears we never consumed the values from the VM. I'll make the helpers requested.

(In reply to comment #5) > Delete "EXTERN cti_vm_handle_exception : near" in JITStubsMSVC64.asm and the MSVC ctiVMHandleException implementation in JITStubsX86.h and this compiles successfully. It runs the tests successfully on Win32 but not on Win64. Alex, thanks for the help. I removed the dead references from those two files. I also found another in jit/JITStubsARM.h.

Committed r157636: <http://trac.webkit.org/changeset/157636>