Thanks Richi!

Tested again and pushed on trunk.

Best,

Arthur

On 5/31/24 15:02, Richard Biener wrote:
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


--
Arthur Cohen <arthur.co...@embecosm.com>

Toolchain Engineer

Embecosm GmbH

Geschäftsführer: Jeremy Bennett
Niederlassung: Nürnberg
Handelsregister: HR-B 36368
www.embecosm.de

Fürther Str. 27
90429 Nürnberg


Tel.: 091 - 128 707 040
Fax: 091 - 128 707 077

Attachment: OpenPGP_0x1B3465B044AD9C65.asc
Description: OpenPGP public key

Attachment: OpenPGP_signature.asc
Description: OpenPGP digital signature

Reply via email to