On Fri, May 31, 2024 at 12:24 PM Arthur Cohen <arthur.co...@embecosm.com> wrote:
>
> Hi Richard,
>
> On 4/30/24 09:55, Richard Biener wrote:
> > On Fri, Apr 19, 2024 at 11:49 AM Arthur Cohen <arthur.co...@embecosm.com>
> > wrote:
> >>
> >> Hi everyone,
> >>
> >> This patch checks for the presence of dlopen and pthread_create in libc.
> >> If that is not the
> >> case, we check for the existence of -ldl and -lpthread, as these libraries
> >> are required to
> >> link the Rust runtime to our Rust frontend.
> >>
> >> If these libs are not present on the system, then we disable the Rust
> >> frontend.
> >>
> >> This was tested on x86_64, in an environment with a recent GLIBC and in a
> >> container with GLIBC
> >> 2.27.
> >>
> >> Apologies for sending it in so late.
> >
> > For example GCC_ENABLE_PLUGINS simply does
> >
> > # Check -ldl
> > saved_LIBS="$LIBS"
> > AC_SEARCH_LIBS([dlopen], [dl])
> > if test x"$ac_cv_search_dlopen" = x"-ldl"; then
> > pluginlibs="$pluginlibs -ldl"
> > fi
> > LIBS="$saved_LIBS"
> >
> > which I guess would also work for pthread_create? This would simplify
> > the code a bit.
>
> Thanks a lot for the review. I've udpated the patch's content in
> configure.ac per your suggestion. Tested similarly on x86_64 and in a
> container with libc 2.27
LGTM.
Thanks,
Richard.
> From 00669b600a75743523c358ee41ab999b6e9fa0f6 Mon Sep 17 00:00:00 2001
> From: Arthur Cohen <arthur.co...@embecosm.com>
> Date: Fri, 12 Apr 2024 13:52:18 +0200
> Subject: [PATCH] rust: Do not link with libdl and libpthread unconditionally
>
> ChangeLog:
>
> * Makefile.tpl: Add CRAB1_LIBS variable.
> * Makefile.in: Regenerate.
> * configure: Regenerate.
> * configure.ac: Check if -ldl and -lpthread are needed, and if so, add
> them to CRAB1_LIBS.
>
> gcc/rust/ChangeLog:
>
> * Make-lang.in: Remove overazealous LIBS = -ldl -lpthread line, link
> crab1 against CRAB1_LIBS.
> ---
> Makefile.in | 3 +
> Makefile.tpl | 3 +
> configure | 154 ++++++++++++++++++++++++++++++++++++++++++
> configure.ac | 41 +++++++++++
> gcc/rust/Make-lang.in | 6 +-
> 5 files changed, 203 insertions(+), 4 deletions(-)
>
> diff --git a/Makefile.in b/Makefile.in
> index edb0c8a9a42..1753fb6b862 100644
> --- a/Makefile.in
> +++ b/Makefile.in
> @@ -197,6 +197,7 @@ HOST_EXPORTS = \
> $(BASE_EXPORTS) \
> CC="$(CC)"; export CC; \
> ADA_CFLAGS="$(ADA_CFLAGS)"; export ADA_CFLAGS; \
> + CRAB1_LIBS="$(CRAB1_LIBS)"; export CRAB1_LIBS; \
> CFLAGS="$(CFLAGS)"; export CFLAGS; \
> CONFIG_SHELL="$(SHELL)"; export CONFIG_SHELL; \
> CXX="$(CXX)"; export CXX; \
> @@ -450,6 +451,8 @@ GOCFLAGS = $(CFLAGS)
> GDCFLAGS = @GDCFLAGS@
> GM2FLAGS = $(CFLAGS)
>
> +CRAB1_LIBS = @CRAB1_LIBS@
> +
> PKG_CONFIG_PATH = @PKG_CONFIG_PATH@
>
> GUILE = guile
> diff --git a/Makefile.tpl b/Makefile.tpl
> index adbcbdd1d57..4aeaad3c1a5 100644
> --- a/Makefile.tpl
> +++ b/Makefile.tpl
> @@ -200,6 +200,7 @@ HOST_EXPORTS = \
> $(BASE_EXPORTS) \
> CC="$(CC)"; export CC; \
> ADA_CFLAGS="$(ADA_CFLAGS)"; export ADA_CFLAGS; \
> + CRAB1_LIBS="$(CRAB1_LIBS)"; export CRAB1_LIBS; \
> CFLAGS="$(CFLAGS)"; export CFLAGS; \
> CONFIG_SHELL="$(SHELL)"; export CONFIG_SHELL; \
> CXX="$(CXX)"; export CXX; \
> @@ -453,6 +454,8 @@ GOCFLAGS = $(CFLAGS)
> GDCFLAGS = @GDCFLAGS@
> GM2FLAGS = $(CFLAGS)
>
> +CRAB1_LIBS = @CRAB1_LIBS@
> +
> PKG_CONFIG_PATH = @PKG_CONFIG_PATH@
>
> GUILE = guile
> diff --git a/configure b/configure
> index 02b435c1163..a9ea5258f0f 100755
> --- a/configure
> +++ b/configure
> @@ -690,6 +690,7 @@ extra_host_zlib_configure_flags
> extra_host_libiberty_configure_flags
> stage1_languages
> host_libs_picflag
> +CRAB1_LIBS
> PICFLAG
> host_shared
> gcc_host_pie
> @@ -8826,6 +8827,139 @@ fi
>
>
>
> +# Rust requires -ldl and -lpthread if you are using an old glibc that
> does not include them by
> +# default, so we check for them here
> +
> +missing_rust_dynlibs=none
> +
> +{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for library
> containing dlopen" >&5
> +$as_echo_n "checking for library containing dlopen... " >&6; }
> +if ${ac_cv_search_dlopen+:} false; then :
> + $as_echo_n "(cached) " >&6
> +else
> + ac_func_search_save_LIBS=$LIBS
> +cat confdefs.h - <<_ACEOF >conftest.$ac_ext
> +/* end confdefs.h. */
> +
> +/* Override any GCC internal prototype to avoid an error.
> + Use char because int might match the return type of a GCC
> + builtin and then its argument prototype would still apply. */
> +#ifdef __cplusplus
> +extern "C"
> +#endif
> +char dlopen ();
> +int
> +main ()
> +{
> +return dlopen ();
> + ;
> + return 0;
> +}
> +_ACEOF
> +for ac_lib in '' dl; do
> + if test -z "$ac_lib"; then
> + ac_res="none required"
> + else
> + ac_res=-l$ac_lib
> + LIBS="-l$ac_lib $ac_func_search_save_LIBS"
> + fi
> + if ac_fn_c_try_link "$LINENO"; then :
> + ac_cv_search_dlopen=$ac_res
> +fi
> +rm -f core conftest.err conftest.$ac_objext \
> + conftest$ac_exeext
> + if ${ac_cv_search_dlopen+:} false; then :
> + break
> +fi
> +done
> +if ${ac_cv_search_dlopen+:} false; then :
> +
> +else
> + ac_cv_search_dlopen=no
> +fi
> +rm conftest.$ac_ext
> +LIBS=$ac_func_search_save_LIBS
> +fi
> +{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_dlopen" >&5
> +$as_echo "$ac_cv_search_dlopen" >&6; }
> +ac_res=$ac_cv_search_dlopen
> +if test "$ac_res" != no; then :
> + test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
> +
> +fi
> +
> +{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for library
> containing pthread_create" >&5
> +$as_echo_n "checking for library containing pthread_create... " >&6; }
> +if ${ac_cv_search_pthread_create+:} false; then :
> + $as_echo_n "(cached) " >&6
> +else
> + ac_func_search_save_LIBS=$LIBS
> +cat confdefs.h - <<_ACEOF >conftest.$ac_ext
> +/* end confdefs.h. */
> +
> +/* Override any GCC internal prototype to avoid an error.
> + Use char because int might match the return type of a GCC
> + builtin and then its argument prototype would still apply. */
> +#ifdef __cplusplus
> +extern "C"
> +#endif
> +char pthread_create ();
> +int
> +main ()
> +{
> +return pthread_create ();
> + ;
> + return 0;
> +}
> +_ACEOF
> +for ac_lib in '' pthread; do
> + if test -z "$ac_lib"; then
> + ac_res="none required"
> + else
> + ac_res=-l$ac_lib
> + LIBS="-l$ac_lib $ac_func_search_save_LIBS"
> + fi
> + if ac_fn_c_try_link "$LINENO"; then :
> + ac_cv_search_pthread_create=$ac_res
> +fi
> +rm -f core conftest.err conftest.$ac_objext \
> + conftest$ac_exeext
> + if ${ac_cv_search_pthread_create+:} false; then :
> + break
> +fi
> +done
> +if ${ac_cv_search_pthread_create+:} false; then :
> +
> +else
> + ac_cv_search_pthread_create=no
> +fi
> +rm conftest.$ac_ext
> +LIBS=$ac_func_search_save_LIBS
> +fi
> +{ $as_echo "$as_me:${as_lineno-$LINENO}: result:
> $ac_cv_search_pthread_create" >&5
> +$as_echo "$ac_cv_search_pthread_create" >&6; }
> +ac_res=$ac_cv_search_pthread_create
> +if test "$ac_res" != no; then :
> + test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
> +
> +fi
> +
> +
> +if test $ac_cv_search_dlopen = -ldl; then
> + CRAB1_LIBS="$CRAB1_LIBS -ldl"
> +elif test $ac_cv_search_dlopen = no; then
> + missing_rust_dynlibs="libdl"
> +fi
> +
> +if test $ac_cv_search_pthread_create = -lpthread; then
> + CRAB1_LIBS="$CRAB1_LIBS -lpthread"
> +elif test $ac_cv_search_pthread_crate = no; then
> + missing_rust_dynlibs="$missing_rust_dynlibs, libpthread"
> +fi
> +
> +CRAB1_LIBS="$CRAB1_LIBS"
> +
> +
> # If we are building PIC/PIE host executables, and we are building
> dependent
> # libs (e.g. GMP) in-tree those libs need to be configured to generate PIC
> # code.
> @@ -9066,6 +9200,26 @@ $as_echo "$as_me: WARNING: GDC is required to
> build $language" >&2;}
> ;;
> esac
>
> + # Disable Rust if we are missing some required C libraries for
> the Rust runtime.
> + case ${add_this_lang}:${language}:${missing_rust_dynlibs} in
> + *:rust:none)
> + # Nothing to do - we're not missing any C libraries
> + ;;
> + yes:rust:*)
> + as_fn_error $? "some C libraries are required to build
> $language: $missing_rust_dynlibs" "$LINENO" 5
> + add_this_lang=unsupported
> + ;;
> + all:rust:*)
> + { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: some C
> libraries are required to build $language: $missing_rust_dynlibs" >&5
> +$as_echo "$as_me: WARNING: some C libraries are required to build
> $language: $missing_rust_dynlibs" >&2;}
> + add_this_lang=unsupported
> + ;;
> + *:rust:*)
> + # Silently disable.
> + add_this_lang=unsupported
> + ;;
> + esac
> +
> # Disable jit if -enable-host-shared not specified
> # but not if building for Mingw. All code in Windows
> # is position independent code (PIC).
> diff --git a/configure.ac b/configure.ac
> index 1a19c07a27b..adb738ac346 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -2036,6 +2036,28 @@ fi
>
> AC_SUBST(PICFLAG)
>
> +# Rust requires -ldl and -lpthread if you are using an old glibc that
> does not include them by
> +# default, so we check for them here
> +
> +missing_rust_dynlibs=none
> +
> +AC_SEARCH_LIBS([dlopen], [dl])
> +AC_SEARCH_LIBS([pthread_create], [pthread])
> +
> +if test $ac_cv_search_dlopen = -ldl; then
> + CRAB1_LIBS="$CRAB1_LIBS -ldl"
> +elif test $ac_cv_search_dlopen = no; then
> + missing_rust_dynlibs="libdl"
> +fi
> +
> +if test $ac_cv_search_pthread_create = -lpthread; then
> + CRAB1_LIBS="$CRAB1_LIBS -lpthread"
> +elif test $ac_cv_search_pthread_crate = no; then
> + missing_rust_dynlibs="$missing_rust_dynlibs, libpthread"
> +fi
> +
> +AC_SUBST(CRAB1_LIBS, "$CRAB1_LIBS")
> +
> # If we are building PIC/PIE host executables, and we are building
> dependent
> # libs (e.g. GMP) in-tree those libs need to be configured to generate PIC
> # code.
> @@ -2273,6 +2295,25 @@ if test -d ${srcdir}/gcc; then
> ;;
> esac
>
> + # Disable Rust if we are missing some required C libraries for
> the Rust runtime.
> + case ${add_this_lang}:${language}:${missing_rust_dynlibs} in
> + *:rust:none)
> + # Nothing to do - we're not missing any C libraries
> + ;;
> + yes:rust:*)
> + AC_MSG_ERROR([some C libraries are required to build
> $language: $missing_rust_dynlibs])
> + add_this_lang=unsupported
> + ;;
> + all:rust:*)
> + AC_MSG_WARN([some C libraries are required to build
> $language: $missing_rust_dynlibs])
> + add_this_lang=unsupported
> + ;;
> + *:rust:*)
> + # Silently disable.
> + add_this_lang=unsupported
> + ;;
> + esac
> +
> # Disable jit if -enable-host-shared not specified
> # but not if building for Mingw. All code in Windows
> # is position independent code (PIC).
> diff --git a/gcc/rust/Make-lang.in b/gcc/rust/Make-lang.in
> index dd94c9b5eab..edcf2ee4c7b 100644
> --- a/gcc/rust/Make-lang.in
> +++ b/gcc/rust/Make-lang.in
> @@ -54,8 +54,6 @@ GCCRS_D_OBJS = \
> rust/rustspec.o \
> $(END)
>
> -LIBS += -ldl -lpthread
> -
> gccrs$(exeext): $(GCCRS_D_OBJS) $(EXTRA_GCC_OBJS) libcommon-target.a
> $(LIBDEPS)
> +$(LINKER) $(ALL_LINKERFLAGS) $(LDFLAGS) -o $@ \
> $(GCCRS_D_OBJS) $(EXTRA_GCC_OBJS) libcommon-target.a \
> @@ -234,7 +232,7 @@ crab1$(exeext): $(RUST_ALL_OBJS) attribs.o
> $(BACKEND) $(LIBDEPS) $(LIBPROC_MACRO
> @$(call LINK_PROGRESS,$(INDEX.rust),start)
> +$(LLINKER) $(ALL_LINKERFLAGS) $(LDFLAGS) -o $@ \
> $(RUST_ALL_OBJS) attribs.o $(BACKEND) \
> - $(LIBS) $(LIBPROC_MACRO_INTERNAL) $(LIBFORMAT_PARSER)
> $(LIBFFI_POLONIUS) \
> + $(LIBS) $(CRAB1_LIBS) $(LIBPROC_MACRO_INTERNAL)
> $(LIBFORMAT_PARSER) $(LIBFFI_POLONIUS) \
> $(BACKENDLIBS)
> @$(call LINK_PROGRESS,$(INDEX.rust),end)
>
> @@ -496,4 +494,4 @@ rust/libffi_polonius.a: \
> rust/checks/errors/borrowck/ffi-polonius/Cargo.toml \
> $(wildcard $(srcdir)/rust/checks/errors/borrowck/ffi-polonius/src/*)
> cargo build --manifest-path
> $(srcdir)/rust/checks/errors/borrowck/ffi-polonius/Cargo.toml --release
> --target-dir rust/ffi-polonius
> - cp rust/ffi-polonius/release/libffi_polonius.a rust/libffi_polonius.a
> \ No newline at end of file
> + cp rust/ffi-polonius/release/libffi_polonius.a rust/libffi_polonius.a
> --
> 2.42.0
>
