* m4/m4.m4: New, from CVS Autoconf.

[bison.git] / src / output.c

diff --git a/src/output.c b/src/output.c
index 171f66cb3016c3211c7aedc7f8e0cf45260c970b..65a7d5b294fa1d9a3c969d01e67db74beaa12f5a 100644 (file)
--- a/src/output.c
+++ b/src/output.c
@@ -1001,15 +1001,17 @@ output_skeleton (void)
   /* Invoke m4 on the definition of the muscles, and the skeleton. */
   {
     const char *bison_pkgdatadir = getenv ("BISON_PKGDATADIR");
+    const char *m4 = getenv ("M4");
+    if (!m4)
+      m4 = M4;
     if (!bison_pkgdatadir)
       bison_pkgdatadir = PKGDATADIR;
     if (trace_flag)
       fprintf (stderr,
-              "running: m4 -I %s m4sugar/m4sugar.m4 %s %s\n",
-              bison_pkgdatadir, tempfile, skeleton);
-    skel_in = readpipe ("m4",
-                       "-I",
-                       bison_pkgdatadir,
+              "running: %s -I %s m4sugar/m4sugar.m4 %s %s\n",
+              m4, bison_pkgdatadir, tempfile, skeleton);
+    skel_in = readpipe (m4,
+                       "-I", bison_pkgdatadir,
                        "m4sugar/m4sugar.m4",
                        tempfile,
                        skeleton,