diff options
Diffstat (limited to 'configure.ac')
| -rw-r--r-- | configure.ac | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/configure.ac b/configure.ac index 9938ab0dc2..a64aeb9979 100644 --- a/configure.ac +++ b/configure.ac @@ -634,6 +634,30 @@ if ${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS \ fi rm -f conftest*]) +# Check if gcc supports attribute ifunc as it is used in libc_ifunc macro. +AC_CACHE_CHECK([for gcc attribute ifunc support], + libc_cv_gcc_indirect_function, [dnl +cat > conftest.c <<EOF +extern int func (int); +int used_func (int a) +{ + return a; +} +static void *resolver () +{ + return &used_func; +} +extern __typeof (func) func __attribute__ ((ifunc ("resolver"))); +EOF +libc_cv_gcc_indirect_function=no +if ${CC-cc} -c conftest.c -o conftest.o 1>&AS_MESSAGE_LOG_FD \ + 2>&AS_MESSAGE_LOG_FD ; then + if $READELF -s conftest.o | grep IFUNC >/dev/null 2>&AS_MESSAGE_LOG_FD; then + libc_cv_gcc_indirect_function=yes + fi +fi +rm -f conftest*]) + if test x"$libc_cv_ld_gnu_indirect_function" != xyes; then if test x"$multi_arch" = xyes; then AC_MSG_ERROR([--enable-multi-arch support requires assembler and linker support]) @@ -641,6 +665,11 @@ if test x"$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. +Please use a gcc which supports it by default or configure gcc with --enable-gnu-indirect-function]) +fi multi_arch_d= if test x"$multi_arch" != xno; then multi_arch_d=/multiarch @@ -1782,6 +1811,10 @@ if test x"$libc_cv_ld_gnu_indirect_function" = xyes; then AC_DEFINE(HAVE_IFUNC) fi +if test x"$libc_cv_gcc_indirect_function" = xyes; then + AC_DEFINE(HAVE_GCC_IFUNC) +fi + # This is far from the AC_ARG_ENABLE that sets it so that a sysdeps # configure fragment can override the value to prevent this AC_DEFINE. AC_SUBST(use_nscd) |