Enable execstack tests only if compiler supports trampoline

Since trampoline is required to test execstack, enable execstack tests
only if compiler supports trampoline.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Sam James <sam@gentoo.org>

1 files changed, 47 insertions, 0 deletions

diff --git a/configure b/configure
index b899d39..aaad07e 100755
--- a/configure
+++ b/configure
@@ -7774,6 +7774,53 @@ config_vars="$config_vars
 cc-option-wimplicit-fallthrough = $libc_cv_cc_wimplicit_fallthrough"
 
 
+conftest_code="
+void bar (void (*callback) (void));
+int foo (void)
+{
+  int var = 0;
+  void callback (void) { var = 1; }
+  bar (callback);
+  return var;
+}
+"
+
+
+cat > conftest.c <<EOF
+$conftest_code
+EOF
+
+saved_CC="$CC"
+CC="$TEST_CC"
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking support for trampolines in testing" >&5
+printf %s "checking support for trampolines in testing... " >&6; }
+if test ${libc_cv_test_cc_trampolines+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e)     if { ac_try='${CC-cc} $CFLAGS $CPPFLAGS -c -Werror conftest.c -o conftest 1>&5'
+  { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; }
+    then
+      libc_cv_test_cc_trampolines=yes
+    else
+      libc_cv_test_cc_trampolines=no
+
+    fi ;;
+esac
+fi
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $libc_cv_test_cc_trampolines" >&5
+printf "%s\n" "$libc_cv_test_cc_trampolines" >&6; }
+
+CC="$saved_CC"
+
+rm -f conftest*
+config_vars="$config_vars
+have-test-cc-trampoline = $libc_cv_test_cc_trampolines"
+
 
 
 saved_CC="$CC"