Bison cleanup to use EXIT_FAILURE, EXIT_SUCCESS consistently

[Paul Eggert]

In a couple of places Bison returns exit status 2 for failure, but
I don't see why.  Also, it's not consistent about using EXIT_FAILURE
and EXIT_SUCCESS, and there is some duplicate exit code in getargs.
I installed this patch.

2002-10-21  Paul Eggert  <address@hidden>

        * src/complain.c (fatal_at, fatal): Use EXIT_FAILURE and EXIT_SUCCESS
        rather than 1 and 0.
        * src/main.c (main): Likewise.
        * src/getargs.c (getargs): Likewise.
        * src/reader.c (reader): Likewise.

        * src/getarg.c (getargs): Remove duplicate code for
        "Try `bison --help'".

        * src/files.c (xfopen, xfclose): Use EXIT_FAILURE rather than 2.
        What was that "2" for?

Index: src/complain.c
===================================================================
RCS file: /cvsroot/bison/bison/src/complain.c,v
retrieving revision 1.14
diff -p -u -r1.14 complain.c
--- src/complain.c      21 Oct 2002 05:28:16 -0000      1.14
+++ src/complain.c      22 Oct 2002 04:31:39 -0000
@@ -206,5 +206,5 @@ fatal (const char *message, ...)
   va_end (args);
   putc ('\n', stderr);
   fflush (stderr);
-  exit (1);
+  exit (EXIT_FAILURE);
 }
Index: src/files.c
===================================================================
RCS file: /cvsroot/bison/bison/src/files.c,v
retrieving revision 1.77
diff -p -u -r1.77 files.c
--- src/files.c 21 Oct 2002 05:30:49 -0000      1.77
+++ src/files.c 22 Oct 2002 04:31:40 -0000
@@ -111,7 +111,7 @@ xfopen (const char *name, const char *mo
 
   ptr = fopen (name, mode);
   if (!ptr)
-    error (2, errno, _("cannot open file `%s'"), name);
+    error (EXIT_FAILURE, errno, _("cannot open file `%s'"), name);
 
   return ptr;
 }
@@ -130,7 +130,7 @@ xfclose (FILE *ptr)
 
   result = fclose (ptr);
   if (result == EOF)
-    error (2, errno, _("cannot close file"));
+    error (EXIT_FAILURE, errno, _("cannot close file"));
 
   return result;
 }
Index: src/getargs.c
===================================================================
RCS file: /cvsroot/bison/bison/src/getargs.c,v
retrieving revision 1.44
diff -p -u -r1.44 getargs.c
--- src/getargs.c       21 Oct 2002 18:15:13 -0000      1.44
+++ src/getargs.c       22 Oct 2002 04:31:40 -0000
@@ -337,11 +339,11 @@ getargs (int argc, char *argv[])
        break;
 
       case 'h':
-       usage (0);
+       usage (EXIT_SUCCESS);
 
       case 'V':
        version ();
-       exit (0);
+       exit (EXIT_SUCCESS);
 
       case 'g':
        /* Here, the -g and --graph=FILE options are differentiated.  */
@@ -405,9 +407,7 @@ getargs (int argc, char *argv[])
        break;
 
       default:
-       fprintf (stderr, _("Try `%s --help' for more information.\n"),
-                program_name);
-       exit (1);
+       usage (EXIT_FAILURE);
       }
 
   if (argc - optind != 1)
Index: src/main.c
===================================================================
RCS file: /cvsroot/bison/bison/src/main.c,v
retrieving revision 1.70
diff -p -u -r1.70 main.c
--- src/main.c  12 Aug 2002 14:41:48 -0000      1.70
+++ src/main.c  22 Oct 2002 04:31:40 -0000
@@ -73,8 +73,8 @@ main (int argc, char *argv[])
   reader ();
   timevar_pop (TV_READER);
 
   if (complaint_issued)
-    exit (1);
+    exit (EXIT_FAILURE);
 
   /* Find useless nonterminals and productions and reduce the grammar. */
   timevar_push (TV_REDUCE);
@@ -137,8 +137,8 @@ main (int argc, char *argv[])
 
   /* Stop if there were errors, to avoid trashing previous output
      files.  */
   if (complaint_issued)
-    exit (1);
+    exit (EXIT_FAILURE);
 
   /* Lookaheads are no longer needed. */
   timevar_push (TV_FREE);
Index: src/reader.c
===================================================================
RCS file: /cvsroot/bison/bison/src/reader.c,v
retrieving revision 1.212
diff -p -u -r1.212 reader.c
--- src/reader.c        17 Oct 2002 17:47:33 -0000      1.212
+++ src/reader.c        22 Oct 2002 04:31:41 -0000
@@ -507,8 +507,8 @@ reader (void)
 
   /* If something went wrong during the parsing, don't try to
      continue.  */
   if (complaint_issued)
-    exit (1);
+    exit (EXIT_FAILURE);
 
   /* Grammar has been read.  Do some checking */
   if (nrules == 0)