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authorMike Frysinger <vapier@gentoo.org>2012-10-22 23:40:42 -0400
committerMike Frysinger <vapier@gentoo.org>2012-10-24 17:01:13 -0400
commit0cae3f4b033e441d820f4521fa5736e4e6e4d713 (patch)
tree6dcd02609d8d6100a9950924817db601d9815b10 /configure.in
parentde2b6422c641490b92b3130a519693166323423c (diff)
downloadglibc-0cae3f4b033e441d820f4521fa5736e4e6e4d713.tar.gz
change ifunc assembly test to a link test
The test currently tests the binutils frontend support which passes for all versions of binutils we currently require (2.20+). It doesn't test the backend which is required for ifunc to actually work, and which most targets don't yet support. Change the assembly code so that when we link it, we get a file that has ifunc relocations if the backend supports it. That way we can test to see if binutils supports everything we need. Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Diffstat (limited to 'configure.in')
-rw-r--r--configure.in31
1 files changed, 21 insertions, 10 deletions
diff --git a/configure.in b/configure.in
index b3fab3772b..4f7bc09842 100644
--- a/configure.in
+++ b/configure.in
@@ -23,6 +23,7 @@ AC_SUBST(cross_compiling)
AC_PROG_CPP
# We need the C++ compiler only for testing.
AC_PROG_CXX
+AC_CHECK_TOOL(READELF, readelf, false)
if test "`cd $srcdir; /bin/pwd`" = "`/bin/pwd`"; then
AC_MSG_ERROR([you must configure in a separate build directory])
@@ -566,17 +567,28 @@ if test "$base_machine" = "i386"; then
AC_DEFINE(USE_REGPARMS)
fi
-# For the multi-arch option we need support in the assembler.
-AC_CACHE_CHECK([for assembler gnu_indirect_function symbol type support],
- libc_cv_asm_gnu_indirect_function, [dnl
+# For the multi-arch option we need support in the assembler & linker.
+AC_CACHE_CHECK([for assembler and linker STT_GNU_IFUNC support],
+ libc_cv_ld_gnu_indirect_function, [dnl
cat > conftest.s <<EOF
.type foo,%gnu_indirect_function
+foo:
+.globl _start
+_start:
+.globl __start
+__start:
+.data
+.long foo
EOF
-if ${CC-cc} -c $ASFLAGS conftest.s 1>&AS_MESSAGE_LOG_FD 2>&AS_MESSAGE_LOG_FD;
-then
- libc_cv_asm_gnu_indirect_function=yes
-else
- libc_cv_asm_gnu_indirect_function=no
+libc_cv_ld_gnu_indirect_function=no
+if ${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS \
+ -nostartfiles -nostdlib \
+ -o conftest conftest.s 1>&AS_MESSAGE_LOG_FD 2>&AS_MESSAGE_LOG_FD; then
+ # Do a link to see if the backend supports IFUNC relocs.
+ $READELF -r conftest 1>&AS_MESSAGE_LOG_FD
+ LC_ALL=C $READELF -r conftest | grep 'no relocations' >/dev/null || {
+ libc_cv_ld_gnu_indirect_function=yes
+ }
fi
rm -f conftest*])
@@ -596,7 +608,7 @@ else
AC_MSG_RESULT(yes)
fi
-if test x"$libc_cv_asm_gnu_indirect_function" != xyes; then
+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])
else
@@ -930,7 +942,6 @@ AC_CHECK_PROG_VER(AWK, gawk, --version,
[GNU Awk[^0-9]*\([0-9][0-9.]*\)],
[[3-9].*], critic_missing="$critic_missing gawk")
-AC_CHECK_TOOL(READELF, readelf, false)
AC_CHECK_TOOL(NM, nm, false)
AC_CHECK_PROGS(AUTOCONF, autoconf, no)