[PATCH 2/3] warnings: fix early exit

[Theophile Ranquet]

Treating warnings as errors caused Bison to exit earlier than needed, making it
hide warnings that would have been printed had -Werror not been set.

Also, fix a bug that caused some context information of errors to not be
shown.

* src/complain.c (complaint_issued): Rename as...
(complaint_status): This, and change its type from boolean to
* src/complain.h (err_status): This, new enumeration.
* src/main.c (main): Adjust (only finish early if an actual complaint was
risen, not a mere warning treated an error).
* src/reader.c: Adjust.
* src/scan-code.l (show_sub_message, show_sub_messages): Take a new warnings
argument.
* src/scan-skel.l (flag): Bug fix.
---
 src/complain.c  |  9 ++++++---
 src/complain.h  | 13 ++++++++++++-
 src/main.c      |  6 +++---
 src/reader.c    |  2 +-
 src/scan-code.l | 24 +++++++++++++++---------
 src/scan-skel.l |  2 +-
 6 files changed, 38 insertions(+), 18 deletions(-)

diff --git a/src/complain.c b/src/complain.c
index 0fa812a..2e4e71a 100644
--- a/src/complain.c
+++ b/src/complain.c
@@ -34,7 +34,7 @@ warnings warnings_flag =
 
 warnings errors_flag;
 
-bool complaint_issued;
+err_status complaint_status = status_none;
 static unsigned *indent_ptr = 0;
 
 void
@@ -129,8 +129,11 @@ complains (const location *loc, warnings flags, const char 
*message,
     : flags & (errors_flag | complaint) ? _("error")
     : _("warning");
 
-  complaint_issued |= flags & (complaint | errors_flag);
-  if (flags & (warnings_flag | silent | fatal | complaint))
+  if ((flags & complaint) && complaint_status < status_complaint)
+    complaint_status = status_complaint;
+  else if ((flags & (warnings_flag & errors_flag)) && ! complaint_status)
+    complaint_status = status_warning_as_error;
+  if (flags & (warnings_flag | fatal | complaint))
     error_message (loc, flags, prefix, message, args);
   if (flags & fatal)
     exit (EXIT_FAILURE);
diff --git a/src/complain.h b/src/complain.h
index 6a871d8..56ddfa0 100644
--- a/src/complain.h
+++ b/src/complain.h
@@ -70,7 +70,18 @@ void complain_indent (location const *loc, warnings flags, 
unsigned *indent,
                       char const *message, ...)
   __attribute__ ((__format__ (__printf__, 4, 5)));
 
+
+/** Warnings treated as errors shouldn't stop the execution as regular errors
+    should (because due to their nature, it is safe to go on). Thus, there are
+    three possible execution statuses.  */
+typedef enum
+  {
+    status_none,
+    status_warning_as_error,
+    status_complaint
+  } err_status;
+
 /** Whether an error was reported.  */
-extern bool complaint_issued;
+extern err_status complaint_status;
 
 #endif /* !COMPLAIN_H_ */
diff --git a/src/main.c b/src/main.c
index 9a03630..39b39c7 100644
--- a/src/main.c
+++ b/src/main.c
@@ -94,7 +94,7 @@ main (int argc, char *argv[])
   reader ();
   timevar_pop (TV_READER);
 
-  if (complaint_issued)
+  if (complaint_status == status_complaint)
     goto finish;
 
   /* Find useless nonterminals and productions and reduce the grammar. */
@@ -173,7 +173,7 @@ main (int argc, char *argv[])
 
   /* Stop if there were errors, to avoid trashing previous output
      files.  */
-  if (complaint_issued)
+  if (complaint_status == status_complaint)
     goto finish;
 
   /* Lookahead tokens are no longer needed. */
@@ -215,5 +215,5 @@ main (int argc, char *argv[])
   timevar_stop (TV_TOTAL);
   timevar_print (stderr);
 
-  return complaint_issued ? EXIT_FAILURE : EXIT_SUCCESS;
+  return complaint_status ? EXIT_FAILURE : EXIT_SUCCESS;
 }
diff --git a/src/reader.c b/src/reader.c
index f18b5b8..fb17b01 100644
--- a/src/reader.c
+++ b/src/reader.c
@@ -631,7 +631,7 @@ reader (void)
   gram_parse ();
   prepare_percent_define_front_end_variables ();
 
-  if (! complaint_issued)
+  if (complaint_status  < status_complaint)
     check_and_convert_grammar ();
 
   xfclose (gram_in);
diff --git a/src/scan-code.l b/src/scan-code.l
index 138d2d9..f6e5a14 100644
--- a/src/scan-code.l
+++ b/src/scan-code.l
@@ -398,14 +398,15 @@ get_at_spec(unsigned symbol_index)
 }
 
 static void
-show_sub_message (const char* cp, bool explicit_bracketing,
+show_sub_message (warnings warning,
+                  const char* cp, bool explicit_bracketing,
                   int midrule_rhs_index, char dollar_or_at,
                   unsigned indent, const variant *var)
 {
   const char *at_spec = get_at_spec (var->symbol_index);
 
   if (var->err == 0)
-    complain_indent (&var->loc, silent, &indent,
+    complain_indent (&var->loc, warning, &indent,
                      _("refers to: %c%s at %s"), dollar_or_at,
                      var->id, at_spec);
   else
@@ -442,21 +443,23 @@ show_sub_message (const char* cp, bool 
explicit_bracketing,
                         _(", cannot be accessed from mid-rule action at $%d"),
                         midrule_rhs_index);
 
-      complain_indent (&id_loc, silent, &indent, "%s",
-                       obstack_finish0 (&msg_buf));
+      complain_indent (&id_loc, warning, &indent, "%s",
+                        obstack_finish0 (&msg_buf));
       obstack_free (&msg_buf, 0);
     }
 }
 
 static void
-show_sub_messages (const char* cp, bool explicit_bracketing,
+show_sub_messages (warnings warning,
+                   const char* cp, bool explicit_bracketing,
                    int midrule_rhs_index, char dollar_or_at,
                    unsigned indent)
 {
   unsigned i;
 
   for (i = 0; i < variant_count; ++i)
-    show_sub_message (cp, explicit_bracketing,
+    show_sub_message (Wother | silent,
+                      cp, explicit_bracketing,
                       midrule_rhs_index, dollar_or_at,
                       indent, &variant_table[i]);
 }
@@ -610,7 +613,8 @@ parse_ref (char *cp, symbol_list *rule, int rule_length,
                            len, cp);
 
         if (variant_count > 0)
-          show_sub_messages (cp, explicit_bracketing, midrule_rhs_index,
+          show_sub_messages (complaint,
+                             cp, explicit_bracketing, midrule_rhs_index,
                              dollar_or_at, indent);
         return INVALID_REF;
       }
@@ -621,7 +625,8 @@ parse_ref (char *cp, symbol_list *rule, int rule_length,
           {
             complain_indent (&text_loc, Wother, &indent,
                              _("misleading reference: %s"), quote (text));
-            show_sub_messages (cp, explicit_bracketing, midrule_rhs_index,
+            show_sub_messages (Wother,
+                               cp, explicit_bracketing, midrule_rhs_index,
                                dollar_or_at, indent + SUB_INDENT);
           }
         {
@@ -636,7 +641,8 @@ parse_ref (char *cp, symbol_list *rule, int rule_length,
         unsigned indent = 0;
         complain_indent (&text_loc, complaint, &indent,
                          _("ambiguous reference: %s"), quote (text));
-        show_sub_messages (cp, explicit_bracketing, midrule_rhs_index,
+        show_sub_messages (complaint,
+                           cp, explicit_bracketing, midrule_rhs_index,
                            dollar_or_at, indent + SUB_INDENT);
         return INVALID_REF;
       }
diff --git a/src/scan-skel.l b/src/scan-skel.l
index c1e7b65..a0d9c9e 100644
--- a/src/scan-skel.l
+++ b/src/scan-skel.l
@@ -186,7 +186,7 @@ flag (const char *arg)
   else if (STREQ (arg, "fatal"))
     return fatal;
   else if (STREQ (arg, "note"))
-    return silent;
+    return silent | complaint;
   else if (STREQ (arg, "warn"))
     return Wother;
   else
-- 
1.7.11.4