[bug#72225] [PATCH] _AM_PROG_CC_C_O: clean up after .dSYM directories properly

On Sun, Jul 21, 2024 at 10:16 AM Zack Weinberg <[email protected]> wrote:
>
> On Sun, Jul 21, 2024, at 5:20 AM, Eric Gallager via Patches for Automake wrote:
> > On darwin, the compiler will generate .dSYM directories (for debug
> > info) alongside executables when invoked, leading to messages like the
> > following in configure output:
> >
> > checking whether /usr/local/bin/gcc understands -c and -o together...
> > rm: conftest.dSYM: is a directory
> > yes
> >
> > The attached patch ought to fix this by passing the -r flag to the rm
> > invocation that's meant to clean up the conftests. One concern,
> > though, is that in the same invocation, it also tries to remove
> > anything called "core", so I worry what might happen with this change
> > if "core" happens to be a directory... should I handle that
> > separately?
>
> Tests generated by autoconf proper use this formula for cleaning up after
> link tests:
>
> rm -f -r a.out a.exe b.out conftest.$ac_ext conftest.o conftest.obj conftest.dSYM
>
> I'd suggest that _AM_PROG_CC_C_O should be aligned with this - which means
> *not* deleting anything named 'core'.  You may or may not have $ac_ext available;

ac_ext is used just a few lines above in the call to AM_RUN_LOG on line 26.

> even if you don't I'd suggest that you also make the 'conftest*' glob more
> specific (without having looked at the rest of am-prog-cc-c-o.m4, something
> like 'conftest.c conftest.o conftest.obj conftest.dSYM' is probably close).
>
> zw

Attached is a new patch that removes 'core' from the list of files to
be deleted, and adds some of your suggestions instead.

diff --git a/m4/prog-cc-c-o.m4 b/m4/prog-cc-c-o.m4
index a31a4a414..bb60b39a9 100644
--- a/m4/prog-cc-c-o.m4
+++ b/m4/prog-cc-c-o.m4
@@ -31,7 +31,9 @@ AC_CACHE_CHECK(
       break
     fi
   done
-  rm -f core conftest*
+  rm -f -r a.out a.exe b.out conftest.$ac_ext conftest.$ac_objext \
+    conftest.dSYM conftest1.$ac_ext conftest1.$ac_objext conftest1.dSYM \
+    conftest2.$ac_ext conftest2.$ac_objext conftest2.dSYM
   unset am_i])
 if test "$am_cv_prog_cc_c_o" != yes; then
    # Losing compiler, so override with the script.