diff options
Diffstat (limited to 'configure.ac')
| -rw-r--r-- | configure.ac | 37 |
1 files changed, 34 insertions, 3 deletions
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 |