diff options
| -rw-r--r-- | ChangeLog | 4 | ||||
| -rwxr-xr-x | configure | 45 | ||||
| -rw-r--r-- | configure.ac | 37 |
3 files changed, 80 insertions, 6 deletions
@@ -1,5 +1,9 @@ 2017-10-20 Adhemerval Zanella <adhemerval.zanella@linaro.org> + * configure.ac (libc_cv_gcc_incompatbile_alias): New define: + indicates whether compiler emits an warning for alias for + functions with incompatible types. + [BZ #22273] * sysdeps/unix/sysv/linux/spawni.c (__spawnix): Handle the case where the auxiliary process is terminated by a signal before calling _exit @@ -3996,6 +3996,32 @@ fi { $as_echo "$as_me:${as_lineno-$LINENO}: result: $libc_cv_gcc_indirect_function" >&5 $as_echo "$libc_cv_gcc_indirect_function" >&6; } +# Check if gcc warns about alias for function with incompatible types. +{ $as_echo "$as_me:${as_lineno-$LINENO}: checking if compiler warns about alias for function with incompatible types" >&5 +$as_echo_n "checking if compiler warns about alias for function with incompatible types... " >&6; } +if ${libc_cv_gcc_incompatible_alias+:} false; then : + $as_echo_n "(cached) " >&6 +else + cat > conftest.c <<EOF +int __redirect_foo (const void *s, int c); + +__typeof (__redirect_foo) *foo_impl (void) __asm__ ("foo"); +__typeof (__redirect_foo) *foo_impl (void) +{ + return 0; +} + +extern __typeof (__redirect_foo) foo_alias __attribute__ ((alias ("foo"))); +EOF +libc_cv_gcc_incompatible_alias=yes +if ${CC-cc} -Werror -c conftest.c -o conftest.o 1>&5 2>&5 ; then + libc_cv_gcc_incompatible_alias=no +fi +rm -f conftest* +fi +{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libc_cv_gcc_incompatible_alias" >&5 +$as_echo "$libc_cv_gcc_incompatible_alias" >&6; } + if test x"$libc_cv_ld_gnu_indirect_function" != xyes; then if test x"$multi_arch" = xyes; then as_fn_error $? "--enable-multi-arch support requires assembler and linker support" "$LINENO" 5 @@ -4003,12 +4029,25 @@ if test x"$libc_cv_ld_gnu_indirect_function" != xyes; then multi_arch=no fi fi -if test x"$libc_cv_gcc_indirect_function" != xyes && - test x"$multi_arch" = xyes; then - { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: --enable-multi-arch support recommends a gcc with gnu-indirect-function support. +if test x"$libc_cv_gcc_indirect_function" != xyes; then + # GCC 8+ emits a warning for alias with incompatible types and it might + # fail to build ifunc resolvers aliases to either weak or internal + # symbols. Disables multiarch build in this case. + if test x"$libc_cv_gcc_incompatible_alias" == xyes; then + { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: gcc emits a warning for alias between functions of incompatible types" >&5 +$as_echo "$as_me: WARNING: gcc emits a warning for alias between functions of incompatible types" >&2;} + if test x"$multi_arch" = xyes; then + as_fn_error $? "--enable-multi-arch support requires a gcc with gnu-indirect-function support" "$LINENO" 5 + fi + { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: Multi-arch is disabled." >&5 +$as_echo "$as_me: WARNING: Multi-arch is disabled." >&2;} + multi_arch=no + elif test x"$multi_arch" = xyes; then + { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: --enable-multi-arch support recommends a gcc with gnu-indirect-function support. Please use a gcc which supports it by default or configure gcc with --enable-gnu-indirect-function" >&5 $as_echo "$as_me: WARNING: --enable-multi-arch support recommends a gcc with gnu-indirect-function support. Please use a gcc which supports it by default or configure gcc with --enable-gnu-indirect-function" >&2;} + fi fi multi_arch_d= if test x"$multi_arch" != xno; then diff --git a/configure.ac b/configure.ac index 195e81acfd..148f7d1682 100644 --- a/configure.ac +++ b/configure.ac @@ -634,6 +634,26 @@ if ${CC-cc} -c conftest.c -o conftest.o 1>&AS_MESSAGE_LOG_FD \ fi rm -f conftest*]) +# Check if gcc warns about alias for function with incompatible types. +AC_CACHE_CHECK([if compiler warns about alias for function with incompatible types], + libc_cv_gcc_incompatible_alias, [dnl +cat > conftest.c <<EOF +int __redirect_foo (const void *s, int c); + +__typeof (__redirect_foo) *foo_impl (void) __asm__ ("foo"); +__typeof (__redirect_foo) *foo_impl (void) +{ + return 0; +} + +extern __typeof (__redirect_foo) foo_alias __attribute__ ((alias ("foo"))); +EOF +libc_cv_gcc_incompatible_alias=yes +if ${CC-cc} -Werror -c conftest.c -o conftest.o 1>&AS_MESSAGE_LOG_FD 2>&AS_MESSAGE_LOG_FD ; then + libc_cv_gcc_incompatible_alias=no +fi +rm -f conftest*]) + if test x"$libc_cv_ld_gnu_indirect_function" != xyes; then if test x"$multi_arch" = xyes; then AC_MSG_ERROR([--enable-multi-arch support requires assembler and linker support]) @@ -641,10 +661,21 @@ if test x"$libc_cv_ld_gnu_indirect_function" != xyes; then multi_arch=no fi fi -if test x"$libc_cv_gcc_indirect_function" != xyes && - test x"$multi_arch" = xyes; then - AC_MSG_WARN([--enable-multi-arch support recommends a gcc with gnu-indirect-function support. +if test x"$libc_cv_gcc_indirect_function" != xyes; then + # GCC 8+ emits a warning for alias with incompatible types and it might + # fail to build ifunc resolvers aliases to either weak or internal + # symbols. Disables multiarch build in this case. + if test x"$libc_cv_gcc_incompatible_alias" == xyes; then + AC_MSG_WARN([gcc emits a warning for alias between functions of incompatible types]) + if test x"$multi_arch" = xyes; then + AC_MSG_ERROR([--enable-multi-arch support requires a gcc with gnu-indirect-function support]) + fi + AC_MSG_WARN([Multi-arch is disabled.]) + multi_arch=no + elif test x"$multi_arch" = xyes; then + AC_MSG_WARN([--enable-multi-arch support recommends a gcc with gnu-indirect-function support. Please use a gcc which supports it by default or configure gcc with --enable-gnu-indirect-function]) + fi fi multi_arch_d= if test x"$multi_arch" != xno; then |