https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114116
--- Comment #8 from H.J. Lu <hjl.tools at gmail dot com> --- (In reply to Lukas Grätz from comment #7) > (In reply to H.J. Lu from comment #6) > > (In reply to Jakub Jelinek from comment #5) > > > Yeah. Not to mention, one can call backtrace even if -g0; you just don't > > > get nice names for the addresses. Without the patch you get crashes in > > > the > > > unwinder when doing backtrace. > > > > Should we generate REG_CFA_UNDEFINED for unsaved callee-saved registers to > > help unwinder: > > > > https://patchwork.sourceware.org/project/gcc/list/?series=30327 > > Yes. Also for gdb this is needed. > > Perhaps I did something wrong. On my computer, I could get the first patch > working to save rbp, I also applied the patch which should omit the > .cfi_undefined. But somehow, I still not get .cfi_undefined for any of the > examples. > > > $ ./gcc/host-x86_64-pc-linux-gnu/gcc/cc1 -O3 > gcc/gcc/testsuite/gcc.target/i386/pr38534-7.c -o pr38534-7.S > > $ cat pr38534-7.S > [...] > no_return_to_caller: > .LFB0: > .cfi_startproc > pushq %rbp > .cfi_def_cfa_offset 16 > .cfi_offset 6, -16 > movl $array+67108860, %eax > xorl %r13d, %r13d > [...] > > > The ".cfi_undefined 13" is still missing... It is generated only when -g is used.
