[PATCH] work around ppc-vx6 make limitations

[Jonathan Wakely]

CC Jason who added those make targets.

On Wed, 24 Jun 2026 at 10:57, Alexandre Oliva <oliva@adacore.com> wrote:
>
>
> libstdc++-v3 in gcc-15 gained uses of a make function that was added
> in GNU make 3.81, but ppc-vx6 is GNU make 3.80, so calling the
> function returns an empty string, and the build fails.
>
> gcc/doc/install.texi states GCC requires make 3.80 to build, so
> rewrite those bits to avoid the new function.

GNU Make 3.81 was 20 years old in April so this is depressing.

>
> Install locations don't need abspath because they're already supposed
> to be absolute, since installation can't work with relative paths and
> DESTDIR is supposed to be prependable.
>
> $? may gain the srcdir VPATH, which would complicate dropping abspath,
> so iterate over the two filenames.
>
> Regstrapped on x86_64-linux-gnu.  Also tested with ppc-vx6's make for
> i686-linux-gnu with gcc-15.  Ok to install?

OK for trunk, 16 and 15.

>
>
> for  libstdc++-v3/ChangeLog
>
>         * src/c++23/Makefile.am (libstdc++.modules.json): Rewrite
>         without abspath make function.
>         (stamp-modules-bits): Likewise.
>         * src/c++23/Makefile.in: Rebuilt.
> ---
>  libstdc++-v3/src/c++23/Makefile.am |    8 +++++---
>  libstdc++-v3/src/c++23/Makefile.in |    8 +++++---
>  2 files changed, 10 insertions(+), 6 deletions(-)
>
> diff --git a/libstdc++-v3/src/c++23/Makefile.am b/libstdc++-v3/src/c++23/Makefile.am
> index 5b2812abd2288..a1acf3eb5b4aa 100644
> --- a/libstdc++-v3/src/c++23/Makefile.am
> +++ b/libstdc++-v3/src/c++23/Makefile.am
> @@ -37,8 +37,8 @@ includebits_DATA = std.cc std.compat.cc
>  # The manifest to be installed uses the relative path between install dirs.
>  libstdc++.modules.json: libstdc++.modules.json.in
>         relpath=$$($(toplevel_srcdir)/contrib/relpath.sh \
> -                  $(abspath $(toolexeclibdir)) \
> -                  $(abspath $(includebitsdir))) && \
> +                   $(toolexeclibdir) \
> +                   $(includebitsdir)) && \
>         sed "s,@MODPATH@,$$relpath," $< > $@
>
>  # The uninstalled manifest uses the relative path to builddir.
> @@ -57,7 +57,9 @@ std.compat.cc: std.compat.cc.in std-clib.cc.in
>  # Also put the interface units in the build-includes bits directory.
>  stamp-modules-bits: $(includebits_DATA)
>         @-mkdir -p $(top_builddir)/include/bits
> -       -cd $(top_builddir)/include/bits && $(LN_S) $(abspath $?) . 2>/dev/null
> +       -for f in $(includebits_DATA); do \
> +         $(LN_S) $(abs_srcdir)/$$f $(top_builddir)/include/bits; \
> +       done 2>/dev/null
>         @$(STAMP) $@
>
>  all-local: stamp-module-manifest stamp-modules-bits
> diff --git a/libstdc++-v3/src/c++23/Makefile.in b/libstdc++-v3/src/c++23/Makefile.in
> index 75da9c008ab60..c1407d250b1d9 100644
> --- a/libstdc++-v3/src/c++23/Makefile.in
> +++ b/libstdc++-v3/src/c++23/Makefile.in
> @@ -845,8 +845,8 @@ uninstall-am: uninstall-includebitsDATA uninstall-toolexeclibDATA
>  # The manifest to be installed uses the relative path between install dirs.
>  libstdc++.modules.json: libstdc++.modules.json.in
>         relpath=$$($(toplevel_srcdir)/contrib/relpath.sh \
> -                  $(abspath $(toolexeclibdir)) \
> -                  $(abspath $(includebitsdir))) && \
> +                   $(toolexeclibdir) \
> +                   $(includebitsdir)) && \
>         sed "s,@MODPATH@,$$relpath," $< > $@
>
>  # The uninstalled manifest uses the relative path to builddir.
> @@ -865,7 +865,9 @@ std.compat.cc: std.compat.cc.in std-clib.cc.in
>  # Also put the interface units in the build-includes bits directory.
>  stamp-modules-bits: $(includebits_DATA)
>         @-mkdir -p $(top_builddir)/include/bits
> -       -cd $(top_builddir)/include/bits && $(LN_S) $(abspath $?) . 2>/dev/null
> +       -for f in $(includebits_DATA); do \
> +         $(LN_S) $(abs_srcdir)/$$f $(top_builddir)/include/bits; \
> +       done 2>/dev/null
>         @$(STAMP) $@
>
>  all-local: stamp-module-manifest stamp-modules-bits
>
> --
> Alexandre Oliva, happy hacker            https://blog.lx.oliva.nom.br/
> Free Software Activist     FSFLA co-founder     GNU Toolchain Engineer
> More tolerance and less prejudice are key for inclusion and diversity.
> Excluding neuro-others for not behaving ""normal"" is *not* inclusive!
>