Re: [PATCH v2] libgccjit: allow common objects in $(EXTRA_GCC_OBJS) and $(EXTRA_OBJS)

[Xi Ruoyao <xry111@xry111.site>]

Ping.  I'd like to see libgccjit working on LoongArch so I would be able
to submit a Rust port to upstream.

If the result is NACK I'd like to know alternative approaches to fix the
build failure.

I doubt if "jit@gcc.gnu.org" is really used, so CC'ed the JIT maintainer
listed in MAINTAINERS.

On Thu, 2022-05-19 at 16:10 +0800, Yang Yujie wrote:
> Hello,
> 
> This patch fixes libgccjit build failure on loongarch* targets,
> and could probably be useful for future ports.
> 
> For now, libgccjit is linked with objects from $(EXTRA_GCC_OBJS) and
> libbackend.a, which contains object files from $(EXTRA_OBJS).
> 
> This effectively forbids any overlap between those two lists, i.e. all
> target-specific shared code between the gcc driver and compiler
> executables must go into gcc/common/config/<arch>/<arch>-common.cc,
> which feels a bit inconvenient when there are a lot of "common" stuff
> that we want to put into separate source files.
> 
> By linking libgccjit with $(EXTRA_GCC_OBJS_EXCLUSIVE), which contains
> all elements from $(EXTRA_GCC_OBJS) but not $(EXTRA_OBJS), this
> problem
> can be alleviated.
> 
> This patch does not affect any other target architecture than
> loongarch,
> and has been bootstrapped and regression-tested on loongarch64-linux-
> gnuf64
> an x86_64-pc-linux-gnu.
> 
> Any recommendations? Please review. Thanks a lot.
> 
> Yujie
> 
> * gcc/jit/ChangeLog:
> 
>         * Make-lang.in: only link objects from $(EXTRA_GCC_OBJS)
>         that's not in $(EXTRA_OBJS) into libgccjit.
> ---
>  gcc/jit/Make-lang.in | 9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/gcc/jit/Make-lang.in b/gcc/jit/Make-lang.in
> index 6e10abfd0ac..248ec45b729 100644
> --- a/gcc/jit/Make-lang.in
> +++ b/gcc/jit/Make-lang.in
> @@ -157,18 +157,23 @@ LIBGCCJIT_EXTRA_OPTS =
> $(LIBGCCJIT_VERSION_SCRIPT_OPTION) \
>  endif
>  endif
>  
> +# Only link objects from $(EXTRA_GCC_OBJS) that's not already
> +# included in libbackend.a ($(EXTRA_OBJS)).
> +EXTRA_GCC_OBJS_EXCLUSIVE = $(foreach _obj1, $(EXTRA_GCC_OBJS), \
> +       $(if $(filter $(_obj1), $(EXTRA_OBJS)),, $(_obj1)))
> +
>  # We avoid using $(BACKEND) from Makefile.in in order to avoid
> pulling
>  # in main.o
>  $(LIBGCCJIT_FILENAME): $(jit_OBJS) \
>         libbackend.a libcommon-target.a libcommon.a \
>         $(CPPLIB) $(LIBDECNUMBER) \
>         $(LIBDEPS) $(srcdir)/jit/libgccjit.map \
> -       $(EXTRA_GCC_OBJS) $(jit.prev)
> +       $(EXTRA_GCC_OBJS_EXCLUSIVE) $(jit.prev)
>         @$(call LINK_PROGRESS,$(INDEX.jit),start)
>         +$(LLINKER) $(ALL_LINKERFLAGS) $(LDFLAGS) -o $@ -shared \
>              $(jit_OBJS) libbackend.a libcommon-target.a libcommon.a \
>              $(CPPLIB) $(LIBDECNUMBER) $(EXTRA_GCC_LIBS) $(LIBS)
> $(BACKENDLIBS) \
> -            $(EXTRA_GCC_OBJS) \
> +            $(EXTRA_GCC_OBJS_EXCLUSIVE) \
>              $(LIBGCCJIT_EXTRA_OPTS)
>         @$(call LINK_PROGRESS,$(INDEX.jit),end)
>  

-- 
Xi Ruoyao <xry111@xry111.site>
School of Aerospace Science and Technology, Xidian University