On Sun, Mar 13, 2005 at 09:24:19PM +0100, Øyvind Harboe wrote: > Trampolines are strange things... :-) > > - Are nested functions part of the C standard or a GCC extension? > I believe the answer is a GCC extension. I have seen evidence, > but no proof to this effect.
That is right. > - AFAICT, the cris target is saving the value of the > static chain register in the trampoline. How can that work > with recursive functions? Does the cris target PASS or FAIL > gcc.dg/trampoline-1.c? > - Lately e.g. the AMD CPU has added support for making it impossible > to execute code on the stack. The town isn't big enough for > both stack based trampolines and stack code execution protection. > What happens now? Search for PT_GNU_STACK in the list archives. > - Are trampolines used for anything else but nested functions > in C? I believe they are used by Ada. Nested functions in other languages, presumably. > - Many backends do not support trampolines. Are trampolines > something that is ultimately being added to the backends? > - Do (theoretical?) alternatives to trampolines exist? I.e. something > that does not generate code runtime. -- Daniel Jacobowitz CodeSourcery, LLC
