Christian Schafmeister
2014-May-27 20:26 UTC
[LLVMdev] Do the LLVM SJLJ intrinsics interact with C++ exception handling and execute C++ cleanup actions?
Do the LLVM Setjmp/Longjmp intrinsics interact with C++ exception handling and execute C++ cleanup actions? I compiled a small example using setjmp/longjmp using clang and they did not execute C++ cleanup actions and calling longjmp bypassed calling destructors on objects that were allocated between the call to setjmp and longjmp. I’m wondering if the LLVM intrinsics behave differently from setjmp/longjmp. Best, .Chris. Christian Schafmeister Professor, Chemistry Department Temple University
Jim Grosbach
2014-May-27 20:51 UTC
[LLVMdev] Do the LLVM SJLJ intrinsics interact with C++ exception handling and execute C++ cleanup actions?
The intrinsics are completely distinct from the standard library functions. The names are historical legacy from GCC. They’re used for 32-bit iOS exception handling. I’m not aware of them being tested or supported in any other context. -Jim On May 27, 2014, at 1:26 PM, Christian Schafmeister <chris.schaf at verizon.net> wrote:> > > Do the LLVM Setjmp/Longjmp intrinsics interact with C++ exception handling and execute C++ cleanup actions? > > I compiled a small example using setjmp/longjmp using clang and they did not execute C++ cleanup actions and calling longjmp bypassed calling destructors on objects that were allocated between the call to setjmp and longjmp. > > I’m wondering if the LLVM intrinsics behave differently from setjmp/longjmp. > > Best, > > .Chris. > > Christian Schafmeister > Professor, Chemistry Department > Temple University > > > _______________________________________________ > LLVM Developers mailing list > LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu > http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
Christian Schafmeister
2014-May-27 21:43 UTC
[LLVMdev] Do the LLVM SJLJ intrinsics interact with C++ exception handling and execute C++ cleanup actions?
Thank you! I was envisioning all sorts of wonderful uses for the SJLJ intrinsics to implement non-local exits for the Common Lisp CATCH/THROW, BLOCK/RETURN-FROM and TAGBODY/GO special operators that would work in a way that was compatible with C++. Currently I’m using C++ exception handling and it works fine but I have been under the misapprehension from reading http://llvm.org/docs/ExceptionHandling.html#setjmp-longjmp-exception-handling that SJLJ intrinsics were a parallel mechanism to C++ exception handling that offered different trade-offs in run-time cost/overhead. I see now that SJLJ is a more primitive exception handling mechanism for a subset 32-bit iOS. Best, .Chris. On May 27, 2014, at 4:51 PM, Jim Grosbach <grosbach at apple.com> wrote:> The intrinsics are completely distinct from the standard library functions. The names are historical legacy from GCC. They’re used for 32-bit iOS exception handling. I’m not aware of them being tested or supported in any other context. > > -Jim > > On May 27, 2014, at 1:26 PM, Christian Schafmeister <chris.schaf at verizon.net> wrote: > >> >> >> Do the LLVM Setjmp/Longjmp intrinsics interact with C++ exception handling and execute C++ cleanup actions? >> >> I compiled a small example using setjmp/longjmp using clang and they did not execute C++ cleanup actions and calling longjmp bypassed calling destructors on objects that were allocated between the call to setjmp and longjmp. >> >> I’m wondering if the LLVM intrinsics behave differently from setjmp/longjmp. >> >> Best, >> >> .Chris. >> >> Christian Schafmeister >> Professor, Chemistry Department >> Temple University >> >> >> _______________________________________________ >> LLVM Developers mailing list >> LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu >> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev >