I just hit this in a fascinating place. When working on xz, I set `-Werror=suggest-attribute=returns_nonnull`, and the build failed (as I expected it to), but with no visible error from the compiler.
There's a mysterious '>/dev/null 2>&1' on the second line where liblzma_la-common.o is built without PIC. With -fPIC, IPA doesn't end up doing attribute discovery. Without it, it does. This behaviour is insane and we should patch it out. Bug: https://bugs.gentoo.org/135865 Cc: glaub...@physik.fu-berlin.de Signed-off-by: Sam James <s...@gentoo.org> --- Please consider this kind of a PoC for discussion. This came up on the GCC bug tracker the other day which prompted me to post it and get people's opinions. See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=55212#c158. libtool assumes that the warning output with vs without -fPIC is going to be identical, hence the non-PIC build output should be completely suppressed. I think this is a premature optimization at best, and it's caused real confusion to people. Can we drop it? If this looks OK, I can check more closely if I need to remove more bits. build-aux/ltmain.in | 2 -- 1 file changed, 2 deletions(-) diff --git a/build-aux/ltmain.in b/build-aux/ltmain.in index 63377541..48e89042 100644 --- a/build-aux/ltmain.in +++ b/build-aux/ltmain.in @@ -1665,8 +1665,6 @@ compiler." func_append command " -o $obj" fi - # Suppress compiler output if we already did a PIC compilation. - func_append command "$suppress_output" func_show_eval_locale "$command" \ '$opt_dry_run || $RM $removelist; exit $EXIT_FAILURE' base-commit: 22a7e547e9857fc94fe5bc7c921d9a4b49c09f8e -- 2.45.2
