Hi Eli,
> A recent MinGW runtime changed its definition of alloca from an
> inline function to a macro. As result, there's a warning when
> compiling Gnulib's malloca.c:
>
> CC malloca.o
> In file included from malloca.h:21,
> from malloca.c:22:
> ./alloca.h:46: warning: "alloca" redefined
> 46 | # define alloca __builtin_alloca
> |
> In file included from ./alloca.h:44,
> from malloca.h:21,
> from malloca.c:22:
> d:\usr\include\alloca.h:81: note: this is the location of the previous
> definition
> 81 | #define alloca( __request ) __builtin_alloca( __request )
> |
>
> Proposed patch is below. Thanks.
Thanks for the report.
I like your patch. It is better than the '#undef alloca' solution that I
had considered before.
2020-06-29 Bruno Haible <br...@clisp.org>
alloca-opt: Fix warning on mingw.
Reported and solution by Eli Zaretskii <e...@gnu.org> in
<https://lists.gnu.org/archive/html/bug-gnulib/2020-06/msg00069.html>.
* lib/alloca.in.h: On mingw, include <alloca.h> and then test again
whether alloca is defined.
diff --git a/lib/alloca.in.h b/lib/alloca.in.h
index 73516ca..beb022c 100644
--- a/lib/alloca.in.h
+++ b/lib/alloca.in.h
@@ -35,13 +35,16 @@
*/
#ifndef alloca
+ /* Some version of mingw have an <alloca.h> that causes trouble when
+ included after 'alloca' gets defined as a macro. As a workaround,
+ include this <alloca.h> first and define 'alloca' as a macro afterwards
+ if needed. */
+# if defined __GNUC__ && (defined _WIN32 && ! defined __CYGWIN__) &&
@HAVE_ALLOCA_H@
+# include_next <alloca.h>
+# endif
+#endif
+#ifndef alloca
# ifdef __GNUC__
- /* Some version of mingw have an <alloca.h> that causes trouble when
- included after 'alloca' gets defined as a macro. As a workaround,
include
- this <alloca.h> first and define 'alloca' as a macro afterwards. */
-# if (defined _WIN32 && ! defined __CYGWIN__) && @HAVE_ALLOCA_H@
-# include_next <alloca.h>
-# endif
# define alloca __builtin_alloca
# elif defined _AIX
# define alloca __alloca
