Re: GDB 7.99.91 MinGW compilation error in cli-script.c

[Eli Zaretskii <eliz@gnu.org>]

> Date: Wed, 17 May 2017 19:01:23 +0300
> From: Eli Zaretskii <eliz@gnu.org>
> CC: simon.marchi@polymtl.ca, gdb-patches@sourceware.org
> 
> I will probably post later a workaround patch for older versions,
> but that's for master.  I see no reason to delay the release or to
> have the fix on the branch.

Is the below OK?  It's a bit ugly, and a small fix is needed even for
the latest MinGW runtime.

Contrary to what I wrote, maybe it's also should be considered for the
branch.  Let me know what you think.

diff --git a/gdb/cli/cli-script.c b/gdb/cli/cli-script.c
index e0e27ef..ec33a37 100644
--- a/gdb/cli/cli-script.c
+++ b/gdb/cli/cli-script.c
@@ -17,6 +17,23 @@
    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
+#if defined __MINGW32__
+#  include <_mingw.h>
+#  ifndef __MINGW64_VERSION_MAJOR
+// For versions of mingw.org's MinGW runtime before 5.0, make sure
+// libstdc++ headers don't omit portions that require C99.
+#    if __MINGW32_MAJOR_VERSION < 5
+#      ifndef _GLIBCXX_USE_C99
+#        define _GLIBCXX_USE_C99 1
+#      endif
+#    else
+// This is required with mingwrt-5.0 to avoid linking errors due to
+// multiple definitions of vsnprintf.
+#      undef __USE_MINGW_ANSI_STDIO
+#    endif
+#  endif
+#endif
+
 #include "defs.h"
 #include "value.h"
 #include "language.h"		/* For value_true */