More sophisticated attempt at detecting working linker options

On some platforms, the linker is perfectly happy to produce binaries
that won't run if you give it the wrong set of flags.  So when not
cross-compiling, try to link-and-run a little test program, rather
than just linking it.

Possible fix for 6173.

diff --git a/acinclude.m4 b/acinclude.m4
index 43280597a409f972ce96e0edc3413d05eeea225d..ae14411f6bbe483301a0a9238804fd46096d3995 100644 (file)
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -71,9 +71,14 @@ AC_DEFUN([TOR_CHECK_LDFLAGS], [
     CFLAGS="$CFLAGS -pedantic -Werror"
     LDFLAGS="$LDFLAGS $2 $1"
     LIBS="$LIBS $3"
-    AC_TRY_LINK([], [return 0;],
+    AC_RUN_IFELSE([
+#include <stdio.h>
+int main(int argc, char **argv) { fputs("", stdout); return 0; }],
                    [AS_VAR_SET(VAR,yes)],
-                   [AS_VAR_SET(VAR,no)])
+                   [AS_VAR_SET(VAR,no)],
+                  [AC_TRY_LINK([], [return 0;],
+                                    [AS_VAR_SET(VAR,yes)],
+                                    [AS_VAR_SET(VAR,no)])])
     CFLAGS="$tor_saved_CFLAGS"
     LDFLAGS="$tor_saved_LDFLAGS"
     LIBS="$tor_saved_LIBS"

diff --git a/changes/bug6173 b/changes/bug6173
new file mode 100644 (file)
index 0000000..3b467a9
--- /dev/null
+++ b/changes/bug6173
@@ -0,0 +1,5 @@
+  o Major bugfixes:
+    - Make our linker option detection code more robust against linkers
+      where a bad combination of options completes successfully but
+      makes an unrunnable binary. Fixes bug 6173; bugfix on 0.2.3.17-beta.
+