Re: Make special accommodation for cl in _AC_PROG_CC_G

[Braden McDaniel]

On Fri, 2003-07-18 at 00:10, Paul Eggert wrote:
> Braden McDaniel <address@hidden> writes:
> 
> > > Maybe some other strategy would be more general.  Like checking that
> > > adding -g both works and doesn't output any extra messages, or
> > > something like that.
> > 
> > I think finding out what "extra" is would be extremely difficult, if not 
> > impossible, to do in a general way.
> 
> No, it's easy.
> 
> 1.  Compile without -g.  Save the output.  E.g., without_g=`cc -g foo.c`.
> 2.  Compile with -g.  Save the output.  E.g., with_g=`cc foo.c`.
> 3.  Compare the two.  E.g., if test "x$without_g" = "x$with_g"; then ....

Alright... Here's a patch that does that.

-- 
Braden McDaniel                           e-mail: <address@hidden>
<http://endoframe.com>                    Jabber: <address@hidden>

Index: lib/autoconf/c.m4
===================================================================
RCS file: /cvsroot/autoconf/autoconf/lib/autoconf/c.m4,v
retrieving revision 1.181
diff -u -r1.181 c.m4
--- lib/autoconf/c.m4   7 Jul 2003 07:41:07 -0000       1.181
+++ lib/autoconf/c.m4   9 Aug 2003 21:41:26 -0000
@@ -487,25 +487,37 @@
 # plays around with CFLAGS (such as to build both debugging and normal
 # versions of a library), tasteless as that idea is.
 m4_define([_AC_PROG_CC_G],
-[ac_test_CFLAGS=${CFLAGS+set}
-ac_save_CFLAGS=$CFLAGS
+[AC_CACHE_CHECK(whether $CC accepts -g, ac_cv_prog_cc_g,
+[ac_save_CFLAGS=$CFLAGS
+AC_LANG_CONFTEST([AC_LANG_PROGRAM()])
+rm -f conftest.$ac_objext
+CFLAGS=
+eval $ac_compile &> conftest.out
+ac_compile_without_g=`cat conftest.out`
+rm -f conftest.$ac_objext conftest.out
 CFLAGS="-g"
-AC_CACHE_CHECK(whether $CC accepts -g, ac_cv_prog_cc_g,
-              [_AC_COMPILE_IFELSE([AC_LANG_PROGRAM()], [ac_cv_prog_cc_g=yes],
-                                                       [ac_cv_prog_cc_g=no])])
-if test "$ac_test_CFLAGS" = set; then
-  CFLAGS=$ac_save_CFLAGS
-elif test $ac_cv_prog_cc_g = yes; then
-  if test "$GCC" = yes; then
-    CFLAGS="-g -O2"
-  else
-    CFLAGS="-g"
-  fi
+eval $ac_compile &> conftest.out
+ac_compile_with_g=`cat conftest.out`
+rm -f conftest.$ac_objext conftest.out conftest.$ac_ext
+CFLAGS=$ac_save_CFLAGS
+if test "x$ac_compile_without_g" = "x$ac_compile_with_g"; then
+  ac_cv_prog_cc_g=yes
 else
-  if test "$GCC" = yes; then
-    CFLAGS="-O2"
+  ac_cv_prog_cc_g=no
+fi])
+if test -z "$CFLAGS"; then
+  if test $ac_cv_prog_cc_g = yes; then
+    if test "$GCC" = yes; then
+      CFLAGS="-g -O2"
+    else
+      CFLAGS="-g"
+    fi
   else
-    CFLAGS=
+    if test "$GCC" = yes; then
+      CFLAGS="-O2"
+    else
+      CFLAGS=
+    fi
   fi
 fi[]dnl
 ])# _AC_PROG_CC_G