[PATCH 2/6] errors: factor b4_error @directives

[Theophile Ranquet]

Instead of @complain, @warn, and @fatal, use a unique @complain
directive. This directive's first argument is "complain", "warn", etc.

* data/bison.m4 (m4_error): Here.
* src/scan-skel.l (at_directive_perform): Adjust.
(flag): Replace the switch by safer and more explicit if branches.
---
 data/bison.m4   |  2 +-
 src/scan-skel.l | 44 ++++++++++++++++++++++----------------------
 2 files changed, 23 insertions(+), 23 deletions(-)

diff --git a/data/bison.m4 b/data/bison.m4
index 7a05473..56ccc38 100644
--- a/data/bison.m4
+++ b/data/bison.m4
@@ -91,7 +91,7 @@ m4_if(m4_sysval, [0], [], [m4_fatal([$0: cannot write to 
stdout])])])
 #   b4_error([[complain]], [[input.y:2.3]], [[input.y:5.4]],
 #            [[invalid %s]], [[foo]])
 m4_define([b4_error],
-[b4_cat(address@hidden(]$2[@,]$3[@,]$4[]]dnl
+[b4_cat(address@hidden(]$1[@,]$2[@,]$3[@,]$4[]]dnl
 [m4_if([$#], [4], [],
        [m4_foreach([b4_arg],
                    m4_dquote(m4_shift(m4_shift(m4_shift(m4_shift($@))))),
diff --git a/src/scan-skel.l b/src/scan-skel.l
index 607dc3c..4b64623 100644
--- a/src/scan-skel.l
+++ b/src/scan-skel.l
@@ -57,10 +57,10 @@ static void fail_for_invalid_at (char const *at);
   int out_lineno PACIFY_CC (= 0);
   char *outname = NULL;
 
-  /* Currently, only the @warn, @complain, @fatal, @warn_at, @complain_at, and
-     @fatal_at directives take multiple arguments, and the last three already
-     can't take more than 7.  argv[0] is the directive name.  */
-  #define ARGC_MAX 8
+  /* Currently, only the @complain directive takes multiple arguments, and
+     never more than 7, with argv[0] being the directive name and argv[1]
+     being the type of complaint to dispatch. */
+#define ARGC_MAX 9
   int argc = 0;
   char *argv[ARGC_MAX];
 %}
@@ -168,13 +168,15 @@ skel_scanner_free (void)
 static inline warnings
 flag (const char *arg)
 {
-  switch (arg[1])
-    {
-    case 'w': return Wother;
-    case 'c': return complaint;
-    case 'f': return fatal;
-    default: aver (false); break;
-    }
+  /* compare with values issued from b4_error */
+  if (STREQ (arg, "warn"))
+    return Wother;
+  else if (STREQ (arg, "complain"))
+    return complaint;
+  else if (STREQ (arg, "fatal"))
+    return fatal;
+  else
+    aver (false);
 }
 
 static void
@@ -186,23 +188,21 @@ at_directive_perform (int argc, char *argv[], char 
**outnamep, int *out_linenop)
         fail_for_at_directive_too_many_args (argv[0]);
       fputs (last_component (argv[1]), yyout);
     }
-  else if (STREQ (argv[0], "@warn")
-           || STREQ (argv[0], "@complain")
-           || STREQ (argv[0], "@fatal"))
+  else if (STREQ (argv[0], "@complain"))
     {
-      warnings w = flag (*argv);
-      location loc;
-      location *locp = NULL;
       if (argc < 4)
         fail_for_at_directive_too_few_args (argv[0]);
-      if (argv[1] && argv[1][0])
+      warnings w = flag (argv[1]);
+      location loc;
+      location *locp = NULL;
+      if (argv[2] && argv[2][0])
         {
-          boundary_set_from_string (&loc.start, argv[1]);
-          boundary_set_from_string (&loc.end, argv[2]);
+          boundary_set_from_string (&loc.start, argv[2]);
+          boundary_set_from_string (&loc.end, argv[3]);
           locp = &loc;
         }
-      argc -= 2;
-      argv += 2;
+      argc -= 3;
+      argv += 3;
       complain_args (locp, w, argc, argv);
     }
   else if (STREQ (argv[0], "@output"))
-- 
1.7.11.4