On Sun, Dec 21, 2025 at 3:25 AM Alexandre Oliva <[email protected]> wrote:
>
> On Oct 29, 2025, Alexandre Oliva <[email protected]> wrote:
>
> > On Oct 26, 2025, Uros Bizjak <[email protected]> wrote:
> >>> * config.gcc [x86_64-*-*]: Match *m32 target, default to m32
> >>> abi and multilib. Accept 32 or m32 for --with-abi.
>
> >> Shouldn't this target be named x86_64-linux-gnu32?
>
> > In an ideal world, it should. m32 makes it easier to match,
> > distinguishing from x32, and, more importantly, doesn't clash with
> > existing uses such as x86_64-mingw32. (We are actually relying on this
> > config for 32-bit mingw builds running in x86_64 native mode as well)
>
> Here's the complete patch, that, on top of the above, should make it
> clear why matching *32 rather than *m32 would be impractical: there are
> places where we currently match %m32 or *m32 patterns, to enable both
> bootstrap and nonbootstrap builds, where %32 or *32 would match
> unintended preexisting triplets.
>
> Bootstrap and nonbootstrap builds need to be distinguished because the
> final stage is built for 64 or 32 bits, respectively, assuming we start
> from a 64-bit-targeting toolchain.
>
> I suppose we could go for something like abi32 instead, if m32 is deemed
> unacceptable.
>
> This was regstrapped on x86_64-linux-gnu, and built for
> x86_64-linux-gnum32 with and without bootstrap. Ok to install?
>
>
> From: Olivier Hainque <[email protected]>
> Co-Authored-By: Alexandre Oliva <[email protected]>
>
> Enable a 32-bit "native" toolchain on x86_64-linux-gnu, i.e., one that
> targets -m32 by default, despite supporting and potentially running in
> 64-bit mode. Adjust libada and gnattools build machinery to support
> this configuration in both bootstrap and non-bootstrap modes.
>
>
> for gcc/ChangeLog
>
> * config.gcc [x86_64-*-*]: Match *m32 target, default to m32
> abi. Accept 32 or m32 for --with-abi.
>
> for gcc/ada/ChangeLog
>
> * gcc-interface/Make-lang.in (m32_target): Set.
> (not_m32_target, native_target, native_gnattools1): Set.
> (ADA_TOOLS_FLAGS_TO_PASS, gnattools): Handle x86_64 natives
> defaulting to -m32 as cross for gnattools.
> * gcc-interface/Makefile.in (target_cpu): Set to i686 for
> x86_64 configurations defaulting to -m32.
>
> for gnattools/ChangeLog
>
> * configure.ac (default_gnattools_target): Use gnattools-cross
> when not bootstrapping x86_64 configurations defaulting to
> -m32.
> * configure: Rebuild.
I think that *abi32 is better than *m32 (*abi32 really sounds like a
new target with different ABI, while *m32 is just mixing an option
into the target triplet), but otherwise I have no better proposal in
the bikeshedding contest.
Since the patch introduces a new target that doesn't affect existing
targets, I think it is good to go in (with *abi32 suffix).
Thanks,
Uros.
> ---
> gcc/ada/gcc-interface/Make-lang.in | 25 +++++++++++++++++++------
> gcc/ada/gcc-interface/Makefile.in | 7 +++++++
> gcc/config.gcc | 25 +++++++++++++++++++++++++
> gnattools/configure | 10 ++++++++++
> gnattools/configure.ac | 10 ++++++++++
> 5 files changed, 71 insertions(+), 6 deletions(-)
>
> diff --git a/gcc/ada/gcc-interface/Make-lang.in
> b/gcc/ada/gcc-interface/Make-lang.in
> index e768ef60ddf79..c264caa4c94ec 100644
> --- a/gcc/ada/gcc-interface/Make-lang.in
> +++ b/gcc/ada/gcc-interface/Make-lang.in
> @@ -192,10 +192,20 @@ GNATLS_FOR_HOST = $(subst gnatmake,gnatls,$(GNATMAKE))
>
> # There are too many Ada sources to check against here. Let's
> # always force the recursive make.
> +
> +# A native x86_64 compiler defaulting to -m32 is not suitable to build
> +# 64bit host tools. Arrange to build the tools with the base compiler
> +# in this case, as we do for cross configurations.
> +
> +m32_target=$(filter x86_64%m32, $(target))
> +not_m32_target=$(if $(m32_target),,$(target))
> +
> ifeq ($(build), $(host))
> - ifeq ($(host), $(target))
> - # This is a regular native. So use the compiler from our current build
> - # tree.
> + native_target=$(filter $(host), $(target))
> +
> + ifneq ($(and $(native_target), $(not_m32_target)),)
> + # This is a regular native. Use the compiler from our
> + # current build tree.
> ADA_TOOLS_FLAGS_TO_PASS=\
> CC="../../xgcc -B../../" \
> CXX="$(CXX)" \
> @@ -205,8 +215,8 @@ ifeq ($(build), $(host))
> GNATLINK="../../gnatlink" \
> GNATBIND="../../gnatbind"
> else
> - # This is a regular cross compiler. Use the native compiler to compile
> - # the tools.
> + # This is a regular cross compiler or a 64bit native defaulting to -m32.
> + # Use the base native compiler to compile the tools.
>
> # put the host RTS dir first in the PATH to hide the default runtime
> # files that are among the sources
> @@ -792,8 +802,11 @@ gnatbind$(exeext): ada/b_gnatb.o $(CONFIG_H)
> $(GNATBIND_OBJS) $(EXTRA_HOST_OBJS)
> +$(GCC_LINK) -o $@ $(CFLAGS) ada/b_gnatb.o $(GNATBIND_OBJS)
> $(EXTRA_HOST_OBJS) ggc-none.o libcommon-target.a $(LIBS) $(SYSLIBS) $(GNATLIB)
>
> # use target-gcc target-gnatmake target-gnatbind target-gnatlink
> +
> +native_gnattools1=$(if $(not_m32_target),gnattools1,gnattools1-re)
> +
> gnattools: $(CONFIG_H) prefix.o force
> - $(MAKE) -C ada $(ADA_TOOLS_FLAGS_TO_PASS) gnattools1
> + $(MAKE) -C ada $(ADA_TOOLS_FLAGS_TO_PASS) $(native_gnattools1)
> $(MAKE) -C ada $(ADA_TOOLS_FLAGS_TO_PASS) gnattools2
>
> regnattools:
> diff --git a/gcc/ada/gcc-interface/Makefile.in
> b/gcc/ada/gcc-interface/Makefile.in
> index f37893e93feed..2eadf996a1a7e 100644
> --- a/gcc/ada/gcc-interface/Makefile.in
> +++ b/gcc/ada/gcc-interface/Makefile.in
> @@ -358,6 +358,13 @@ ifeq ($(strip $(filter-out x86_64 linux-gnux32%,
> $(target_cpu) $(target_os))),)
> endif
> endif
>
> +# The x86_64-*m32 compilers are x86_64 compilers defaulting to -m32
> +ifeq ($(strip $(filter-out x86_64 %m32, $(target_cpu) $(target_os))),)
> + ifneq ($(strip $(MULTISUBDIR)),/64)
> + target_cpu:=i686
> + endif
> +endif
> +
> # Configuration of host tools
>
> # Under linux, host tools need to be linked with -ldl
> diff --git a/gcc/config.gcc b/gcc/config.gcc
> index ed862ca12f475..fe0136b162ef5 100644
> --- a/gcc/config.gcc
> +++ b/gcc/config.gcc
> @@ -678,6 +678,28 @@ i[34567]86-*-*)
> x86_64-*-darwin*)
> ;;
> x86_64-*-*)
> + # Pick a default with_abi and with_multilib_list for m32
> + # restricted toolchains
> + case ${target} in
> + *m32)
> + case ${with_abi} in
> + "" | 32 | m32)
> + with_abi=m32
> + ;;
> + *)
> + echo "Invalid --with-abi=$with_abi for m32 target"
> + exit 1
> + esac
> + case ${with_multilib_list} in
> + default | *m32*)
> + ;;
> + *)
> + echo "Invalid multilib list for m32 target"
> + exit 1
> + esac
> + ;;
> + esac
> +
> case ${with_abi} in
> "")
> if test "x$with_multilib_list" = xmx32; then
> @@ -692,6 +714,9 @@ x86_64-*-*)
> x32 | mx32)
> tm_file="i386/biarchx32.h ${tm_file}"
> ;;
> + 32 | m32)
> + tm_defines="${tm_defines} TARGET_BI_ARCH=1"
> + ;;
> *)
> echo "Unknown ABI used in --with-abi=$with_abi"
> exit 1
> diff --git a/gnattools/configure b/gnattools/configure
> index b3b6aab1b72ed..16f0b42d7920a 100755
> --- a/gnattools/configure
> +++ b/gnattools/configure
> @@ -3683,6 +3683,16 @@ fi
> # ../gcc/ada/gcc-interface/config-lang.in as well.
> if test "x$cross_compiling/$build/$host" = "xno/$host/$target" ; then
> default_gnattools_target="gnattools-native"
> + # When natively-building x86_64-*m32 tools without bootstrap,
> + # use the native toolchain to build gnattools, expecting its
> + # libraries to be compatible with whichever multilib was used to
> + # build other tools. This requires the compiler being built to be
> + # gnatbind-compatible with the one used for the build.
> + case $enable_bootstrap/$target in
> + no/x86_64-*m32)
> + default_gnattools_target="gnattools-cross"
> + ;;
> + esac
> else
> default_gnattools_target="gnattools-cross"
> fi
> diff --git a/gnattools/configure.ac b/gnattools/configure.ac
> index ff07179b3ba80..9a30864cb91b6 100644
> --- a/gnattools/configure.ac
> +++ b/gnattools/configure.ac
> @@ -125,6 +125,16 @@ AC_SUBST(LD_PICFLAG)
> # ../gcc/ada/gcc-interface/config-lang.in as well.
> if test "x$cross_compiling/$build/$host" = "xno/$host/$target" ; then
> default_gnattools_target="gnattools-native"
> + # When natively-building x86_64-*m32 tools without bootstrap,
> + # use the native toolchain to build gnattools, expecting its
> + # libraries to be compatible with whichever multilib was used to
> + # build other tools. This requires the compiler being built to be
> + # gnatbind-compatible with the one used for the build.
> + case $enable_bootstrap/$target in
> + no/x86_64-*m32)
> + default_gnattools_target="gnattools-cross"
> + ;;
> + esac
> else
> default_gnattools_target="gnattools-cross"
> fi
>
>
>
> --
> 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!
