Use "Unresolved reference" error message when no symbols were found

[bison.git] / src / scan-code.l

diff --git a/src/scan-code.l b/src/scan-code.l
index d976517d6fbacc08d32709e4890c21fb1a590d30..196fa807b867902b8ea22f3d73f91c6a74917b19 100644 (file)
--- a/src/scan-code.l
+++ b/src/scan-code.l
@@ -1,6 +1,6 @@
 /* Bison Action Scanner                             -*- C -*-
 
 /* Bison Action Scanner                             -*- C -*-
 

-   Copyright (C) 2006, 2007, 2008 Free Software Foundation, Inc.
+   Copyright (C) 2006, 2007, 2008-2009 Free Software Foundation, Inc.

 
    This file is part of Bison, the GNU Compiler Compiler.
 
 
    This file is part of Bison, the GNU Compiler Compiler.
 


@@ -17,7 +17,7 @@
    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 

-%option debug nodefault nounput noyywrap never-interactive
+%option debug nodefault noinput nounput noyywrap never-interactive

 %option prefix="code_" outfile="lex.yy.c"
 
 %{
 %option prefix="code_" outfile="lex.yy.c"
 
 %{


@@ -306,7 +306,7 @@ contains_dot_or_dash (const char* p)
 typedef struct
 {
   /* Index in symbol list. */
 typedef struct
 {
   /* Index in symbol list. */

-  unsigned index;
+  unsigned symbol_index;

 
   /* Matched symbol id and loc. */
   uniqstr id;
 
   /* Matched symbol id and loc. */
   uniqstr id;


@@ -375,17 +375,17 @@ find_prefix_end (const char *prefix, char *begin, char *end)
 
 static variant *
 variant_add (uniqstr id, location id_loc, unsigned symbol_index,
 
 static variant *
 variant_add (uniqstr id, location id_loc, unsigned symbol_index,

-            char *cp, char *cp_end, bool exact_mode)
+            char *cp, char *cp_end, bool explicit_bracketing)

 {
   char *prefix_end;
 
   prefix_end = find_prefix_end (id, cp, cp_end);
   if (prefix_end &&
       (prefix_end == cp_end ||
 {
   char *prefix_end;
 
   prefix_end = find_prefix_end (id, cp, cp_end);
   if (prefix_end &&
       (prefix_end == cp_end ||

-       (!exact_mode && is_dot_or_dash (*prefix_end))))
+       (!explicit_bracketing && is_dot_or_dash (*prefix_end))))

     {
       variant *r = variant_table_grow ();
     {
       variant *r = variant_table_grow ();

-      r->index = symbol_index;
+      r->symbol_index = symbol_index;

       r->id = id;
       r->loc = id_loc;
       r->hidden_by = NULL;
       r->id = id;
       r->loc = id_loc;
       r->hidden_by = NULL;


@@ -407,12 +407,78 @@ get_at_spec(unsigned symbol_index)
   return at_buf;
 }
 
   return at_buf;
 }
 

+static void
+show_sub_messages (const char* cp, bool explicit_bracketing,
+                   int midrule_rhs_index, char dollar_or_at, bool is_warning)
+{
+  unsigned i;
+
+  for (i = 0; i < variant_count; ++i)
+    {
+      const variant *var = &variant_table[i];
+      const char *at_spec = get_at_spec (var->symbol_index);
+
+      if (var->err == 0)
+        {
+          if (is_warning)
+            warn_at (var->loc, _("  refers to: %c%s at %s"),
+                     dollar_or_at, var->id, at_spec);
+          else
+            complain_at (var->loc, _("  refers to: %c%s at %s"),
+                         dollar_or_at, var->id, at_spec);
+        }
+      else
+       {
+         static struct obstack msg_buf;
+         const char *tail = explicit_bracketing ? "" :
+           cp + strlen (var->id);
+         const char *id = var->hidden_by ? var->hidden_by->id :
+           var->id;
+         location id_loc = var->hidden_by ? var->hidden_by->loc :
+           var->loc;
+
+         /* Create the explanation message. */
+         obstack_init (&msg_buf);
+
+         obstack_fgrow1 (&msg_buf, "  possibly meant: %c", dollar_or_at);
+         if (contains_dot_or_dash (id))
+           obstack_fgrow1 (&msg_buf, "[%s]", id);
+         else
+           obstack_sgrow (&msg_buf, id);
+         obstack_sgrow (&msg_buf, tail);
+
+         if (var->err & VARIANT_HIDDEN)
+           {
+             obstack_fgrow1 (&msg_buf, ", hiding %c", dollar_or_at);
+             if (contains_dot_or_dash (var->id))
+               obstack_fgrow1 (&msg_buf, "[%s]", var->id);
+             else
+               obstack_sgrow (&msg_buf, var->id);
+             obstack_sgrow (&msg_buf, tail);
+           }
+
+         obstack_fgrow1 (&msg_buf, " at %s", at_spec);
+
+         if (var->err & VARIANT_NOT_VISIBLE_FROM_MIDRULE)
+           obstack_fgrow1 (&msg_buf, ", cannot be accessed from "
+                           "mid-rule action at $%d", midrule_rhs_index);
+
+         obstack_1grow (&msg_buf, '\0');
+          if (is_warning)
+            warn_at (id_loc, _("%s"), (char *) obstack_finish (&msg_buf));
+          else
+            complain_at (id_loc, _("%s"), (char *) obstack_finish (&msg_buf));
+         obstack_free (&msg_buf, 0);
+       }
+    }
+}
+

 /* Returned from "parse_ref" when the reference
    is inappropriate. */
 #define INVALID_REF (INT_MIN)
 
 /* Returned from "parse_ref" when the reference
 /* Returned from "parse_ref" when the reference
    is inappropriate. */
 #define INVALID_REF (INT_MIN)
 
 /* Returned from "parse_ref" when the reference

-   points to LHS ($$) of the current rule. */
+   points to LHS ($$) of the current rule or midrule. */

 #define LHS_REF (INT_MIN + 1)
 
 /* Parse named or positional reference. In case of positional
 #define LHS_REF (INT_MIN + 1)
 
 /* Parse named or positional reference. In case of positional


@@ -425,10 +491,10 @@ parse_ref (char *cp, symbol_list *rule, int rule_length,
 {
   symbol_list *l;
   char *cp_end;
 {
   symbol_list *l;
   char *cp_end;

-  bool exact_mode;
-  bool has_error;
-  bool has_valid;
+  bool explicit_bracketing;

   unsigned i;
   unsigned i;

+  unsigned valid_variants = 0;
+  unsigned valid_variant_index = 0;

 
   if ('$' == *cp)
     return LHS_REF;
 
   if ('$' == *cp)
     return LHS_REF;


@@ -454,7 +520,7 @@ parse_ref (char *cp, symbol_list *rule, int rule_length,
        continue;
       cp_end = p;
 
        continue;
       cp_end = p;
 

-      exact_mode = true;
+      explicit_bracketing = true;

     }
   else
     {
     }
   else
     {


@@ -470,7 +536,7 @@ parse_ref (char *cp, symbol_list *rule, int rule_length,
        continue;
       cp_end = p;
 
        continue;
       cp_end = p;
 

-      exact_mode = false;
+      explicit_bracketing = false;

     }
 
   /* Add all relevant variants. */
     }
 
   /* Add all relevant variants. */


@@ -485,125 +551,93 @@ parse_ref (char *cp, symbol_list *rule, int rule_length,
          continue;
 
        var = variant_add (l->content.sym->tag, l->sym_loc,
          continue;
 
        var = variant_add (l->content.sym->tag, l->sym_loc,

-                           symbol_index, cp, cp_end, exact_mode);
+                           symbol_index, cp, cp_end, explicit_bracketing);

        if (var && l->named_ref)
          var->hidden_by = l->named_ref;
 
        if (l->named_ref)
          variant_add (l->named_ref->id, l->named_ref->loc,
        if (var && l->named_ref)
          var->hidden_by = l->named_ref;
 
        if (l->named_ref)
          variant_add (l->named_ref->id, l->named_ref->loc,

-                       symbol_index, cp, cp_end, exact_mode);
+                       symbol_index, cp, cp_end, explicit_bracketing);

       }
   }
 
   /* Check errors. */
       }
   }
 
   /* Check errors. */

-  has_error = false;
-  has_valid = false;

   for (i = 0; i < variant_count; ++i)
     {
       variant *var = &variant_table[i];
   for (i = 0; i < variant_count; ++i)
     {
       variant *var = &variant_table[i];

-      unsigned symbol_index = var->index;
+      unsigned symbol_index = var->symbol_index;

 
       /* Check visibility from mid-rule actions. */
       if (midrule_rhs_index != 0
          && (symbol_index == 0 || midrule_rhs_index < symbol_index))
 
       /* Check visibility from mid-rule actions. */
       if (midrule_rhs_index != 0
          && (symbol_index == 0 || midrule_rhs_index < symbol_index))

-       {
-         var->err |= VARIANT_NOT_VISIBLE_FROM_MIDRULE;
-         has_error = true;
-       }
+        var->err |= VARIANT_NOT_VISIBLE_FROM_MIDRULE;

 
       /* Check correct bracketing. */
 
       /* Check correct bracketing. */

-      if (!exact_mode && contains_dot_or_dash (var->id))
-       {
-         var->err |= VARIANT_BAD_BRACKETING;
-         has_error = true;
-       }
+      if (!explicit_bracketing && contains_dot_or_dash (var->id))
+        var->err |= VARIANT_BAD_BRACKETING;

 
       /* Check using of hidden symbols. */
       if (var->hidden_by)
 
       /* Check using of hidden symbols. */
       if (var->hidden_by)

-       {
-         var->err |= VARIANT_HIDDEN;
-         has_error = true;
-       }
+        var->err |= VARIANT_HIDDEN;

 
       if (!var->err)
 
       if (!var->err)

-       has_valid = true;
+        {
+          valid_variant_index = i;
+          ++valid_variants;
+        }

     }
 
     }
 

-  if (variant_count == 1 && has_valid)
-    {
-      /* The only "good" case is here. */
-      unsigned symbol_index = variant_table[0].index;
-      if (symbol_index == midrule_rhs_index)
-       return LHS_REF;
-      else
-       return symbol_index;
-    }
-
-  /* Start complaining. */
-
-  if (variant_count == 0)
-    complain_at (text_loc, _("invalid reference: %s, symbol not found"),
-                quote (text));
-  else if (variant_count > 1 && !has_error)
-    complain_at (text_loc, _("ambiguous reference: %s"),
-                quote (text));
-  else if (variant_count > 1 && has_valid && has_error)
-    complain_at (text_loc, _("misleading reference: %s"),
-                quote (text));
-  else
-    complain_at (text_loc, _("invalid reference: %s"),
-                quote (text));
-
-  for (i = 0; i < variant_count; ++i)
+  switch (valid_variants)

     {
     {

-      const variant *var = &variant_table[i];
-      const char *at_spec = get_at_spec (var->index);
-
-      if (var->err == 0)
-       complain_at (var->loc, _("  refers to: %c%s at %s"),
-                    dollar_or_at, var->id, at_spec);
+    case 0:
+      if (variant_count == 0)
+        {
+          if (explicit_bracketing || !ref_tail_fields)
+            complain_at (text_loc, _("unresolved reference: %s"),
+                         quote(text));
+          else
+            {
+              unsigned len = ref_tail_fields - text;
+              char *str = strndup (text, len);
+              text_loc.end.column = text_loc.start.column + len;
+              complain_at (text_loc, _("unresolved reference: %s"),
+                           quote (str));
+              free (str);
+            }
+        }

       else
       else

-       {
-         static struct obstack msg_buf;
-         const char *tail = exact_mode ? "" :
-           cp + strlen (var->id);
-         const char *id = var->hidden_by ? var->hidden_by->id :
-           var->id;
-         location id_loc = var->hidden_by ? var->hidden_by->loc :
-           var->loc;
-
-         /* Create the explanation message. */
-         obstack_init (&msg_buf);
-
-         obstack_fgrow1 (&msg_buf, "  possibly meant: %c", dollar_or_at);
-         if (contains_dot_or_dash (id))
-           obstack_fgrow1 (&msg_buf, "[%s]", id);
-         else
-           obstack_sgrow (&msg_buf, id);
-         obstack_sgrow (&msg_buf, tail);
-
-         if (var->err & VARIANT_HIDDEN)
-           {
-             obstack_fgrow1 (&msg_buf, ", hiding %c", dollar_or_at);
-             if (contains_dot_or_dash (var->id))
-               obstack_fgrow1 (&msg_buf, "[%s]", var->id);
-             else
-               obstack_sgrow (&msg_buf, var->id);
-             obstack_sgrow (&msg_buf, tail);
-           }
-
-         obstack_fgrow1 (&msg_buf, " at %s", at_spec);
-
-         if (var->err & VARIANT_NOT_VISIBLE_FROM_MIDRULE)
-           obstack_fgrow1 (&msg_buf, ", cannot be accessed from "
-                           "mid-rule action at $%d", midrule_rhs_index);
-
-         obstack_1grow (&msg_buf, '\0');
-         complain_at (id_loc, _("%s"), (char *) obstack_finish (&msg_buf));
-         obstack_free (&msg_buf, 0);
-       }
+        {
+          complain_at (text_loc, _("invalid reference: %s"),
+                       quote (text));
+          show_sub_messages (cp, explicit_bracketing, midrule_rhs_index,
+                             dollar_or_at, false);
+        }
+      return INVALID_REF;
+    case 1:
+      {
+        if (variant_count > 1)
+          {
+            warn_at (text_loc, _("misleading reference: %s"),
+                     quote (text));
+            show_sub_messages (cp, explicit_bracketing, midrule_rhs_index,
+                               dollar_or_at, true);
+          }
+        {
+          unsigned symbol_index =
+            variant_table[valid_variant_index].symbol_index;
+          return (symbol_index == midrule_rhs_index) ? LHS_REF : symbol_index;
+        }
+      }
+    case 2:
+    default:
+      complain_at (text_loc, _("ambiguous reference: %s"),
+                   quote (text));
+      show_sub_messages (cp, explicit_bracketing, midrule_rhs_index,
+                         dollar_or_at, false);
+      return INVALID_REF;

     }
 
     }
 

+  /* Not reachable. */

   return INVALID_REF;
 }
 
   return INVALID_REF;
 }