Hi! On Wed, 11 Apr 2018 20:55:49 +0200, Jakub Jelinek <ja...@redhat.com> wrote: > On Wed, Apr 11, 2018 at 06:07:17PM +0200, Matthias Klose wrote: > > On 11.04.2018 12:31, Jakub Jelinek wrote: > > > As discussed, using --as-needed and --no-as-needed is dangerous, because > > > it results in --no-as-needed even for libraries after -lgcc_s, even when > > > the > > > default is --as-needed or --as-needed has been specified earlier on the > > > command line. > > > > > > If the linker supports --push-state/--pop-state, we should IMHO use it. > > > > > > Bootstrapped/regtested on x86_64-linux and i686-linux, ok for stage1?
> > this is problematic for binutils versions with --push-state/--pop-state > > support > > in the BFD linker but not in gold, and then using -fuse-ld=gold. So maybe > > the > > version check for the BFD linker should only succeed for the first binutils > > version which also has -push-state/--pop-state support in gold. > > Does anybody use -fuse-ld=gold? Probably the question is not whether anybody's using that or not, but rather whether it's supported or not, and last time I looked, it was documented in GCC's manual. ;-) > > The BFD linker is only able to save exactly one state, and nested > > --push-state > > calls override the state (binutils PR23043). Otoh, there is not much linked > > after libgcc, so maybe this is not an issue. > > In any case, here is updated patch that will use it only for 2.28+ which > should have both ld.bfd and ld.gold --push-state support. > --- gcc/configure.ac.jj 2018-04-10 14:35:49.764788806 +0200 > +++ gcc/configure.ac 2018-04-11 18:26:16.745563830 +0200 > @@ -5517,11 +5517,25 @@ if test $in_tree_ld = yes ; then > if test "$gcc_cv_gld_major_version" -eq 2 -a "$gcc_cv_gld_minor_version" > -ge 16 -o "$gcc_cv_gld_major_version" -gt 2 \ > && test $in_tree_ld_is_elf = yes; then > gcc_cv_ld_as_needed=yes > + if test "$gcc_cv_gld_major_version" -eq 2 -a "$gcc_cv_gld_minor_version" > -ge 28; then > + gcc_cv_ld_as_needed_option='--push-state --as-needed' > + gcc_cv_ld_no_as_needed_option='--pop-state' > + fi > fi > elif test x$gcc_cv_ld != x; then > # Check if linker supports --as-needed and --no-as-needed options > if $gcc_cv_ld --help 2>&1 | grep as-needed > /dev/null; then > gcc_cv_ld_as_needed=yes > + if $gcc_cv_ld --help 2>&1 | grep push-state > /dev/null \ > + && $gcc_cv_ld --help 2>&1 | grep pop-state > /dev/null \ > + && echo "$ld_ver" | grep GNU > /dev/null \ > + && test "$ld_vers_major" -eq 2 -a "$ld_vers_minor" -ge 28; then > + # Use these options only when both ld.bfd and ld.gold support > + # --push-state/--pop-state, which unfortunately wasn't added > + # at the same time. > + gcc_cv_ld_as_needed_option='--push-state --as-needed' > + gcc_cv_ld_no_as_needed_option='--pop-state' > + fi Is binutils/ld going to stay at major version 2 forever, or should these checks also include '-o "$gcc_cv_gld_major_version" -gt 2', like done a few lines above, for example? (I have not checked now whether that might be a problem for other existing "feature" checks, too.) Grüße Thomas
