| Message ID | BANLkTimD_G4jU3BkSs7YWvwvPe8g9tb5=g@mail.gmail.com |
|---|---|
| State | New |
| Headers | show |
Chris Demetriou <cgd@google.com> writes: > 2011-05-03 Chris Demetriou <cgd@google.com> > > * libgcc/config/i386/morestack.S (__i686.get_pc_thunk.bx): New. No "libgcc" in libgcc/ChangeLog. This is OK. It is also OK if you s/__i686/__x86/ to correspond to your earlier change. Either way is OK. Thanks. Ian
On Tue, May 3, 2011 at 15:05, Ian Lance Taylor <iant@google.com> wrote: > > > 2011-05-03 Chris Demetriou <cgd@google.com> > > > > * libgcc/config/i386/morestack.S (__i686.get_pc_thunk.bx): New. > > No "libgcc" in libgcc/ChangeLog. Fixed, sorry. (That's what I get for pasting from svn status output. 8-) > It is also OK if you s/__i686/__x86/ to correspond to your earlier > change. Either way is OK. Well, that change is not in trunk. Should that change move to trunk, yes, it's appropriate to change this as well (though strictly not *necessary*). (On the google branches, my plan was to rename, yes.) chris
[libgcc/ChangeLog] 2011-05-03 Chris Demetriou <cgd@google.com> * libgcc/config/i386/morestack.S (__i686.get_pc_thunk.bx): New. Index: libgcc/config/i386/morestack.S =================================================================== --- libgcc/config/i386/morestack.S (revision 173287) +++ libgcc/config/i386/morestack.S (working copy) @@ -449,6 +449,24 @@ .size __morestack, . - __morestack #endif +#if !defined(__x86_64__) && defined(__PIC__) +# Output the thunk to get PC into bx, since we use it above. +# (__i686 was already undef'd above; don't need to worry about it here.) + .section .text.__i686.get_pc_thunk.bx,"axG",@progbits,__i686.get_pc_thunk.bx,comdat + .globl __i686.get_pc_thunk.bx + .hidden __i686.get_pc_thunk.bx +#ifdef __ELF__ + .type __i686.get_pc_thunk.bx, @function +#endif +__i686.get_pc_thunk.bx: + .cfi_startproc + movl (%esp), %ebx + ret + .cfi_endproc +#ifdef __ELF__ + .size __i686.get_pc_thunk.bx, . - __i686.get_pc_thunk.bx +#endif +#endif # The exception table. This tells the personality routine to execute # the exception handler.
After I submitted http://gcc.gnu.org/ml/gcc-patches/2011-04/msg02422.html, Rong Xu noted that the resulting sources, if configured --with-pic, would not actually build properly due to missing __i686.get_pc_thunk.bx (due to my renaming that to __x86...). While that issue was exposed by my change, in that configuration, in summary my change exposed a latent issue in morestack.S. (Callers of __i686.get_pc_thunk.bx (etc.) are also supposed to define those functions -- because who knows whether the other objects they're linked against will provide them.) So, I've added the __i686.get_pc_thunk.bx function (as generated by current GCC) to libgcc/config/i386/morestack.S. (I also added __ELF__ #ifdefs and a .size directive for the function, following the apparent conventions in the file.) bootstrapped (C only) on Ubuntu Lucid x86-64, and ran -m32/-m64 tests for compilers configured as normal, and also --with-pic. No regressions before/after. Ian, OK for trunk? chris ---- [libgcc/ChangeLog] 2011-05-03 Chris Demetriou <cgd@google.com> * libgcc/config/i386/morestack.S (__i686.get_pc_thunk.bx): New.