X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/38609c34559fb86f2fb827dfed929ba9c396dc6f..0ab402b48b747a32f5119d2e23b5546254da33a9:/src/scan-code.l?ds=sidebyside

diff --git a/src/scan-code.l b/src/scan-code.l
index 323b49b0..a84b4c1f 100644
--- a/src/scan-code.l
+++ b/src/scan-code.l
@@ -306,7 +306,7 @@ contains_dot_or_dash (const char* p)
 typedef struct
 {
   /* Index in symbol list. */
-  unsigned index;
+  unsigned symbol_index;
 
   /* 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,
-	     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 ||
-       (!exact_mode && is_dot_or_dash (*prefix_end))))
+       (!explicit_bracketing && is_dot_or_dash (*prefix_end))))
     {
       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;
@@ -407,14 +407,89 @@ get_at_spec(unsigned symbol_index)
   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 indent)
+{
+  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_indent (var->loc, &indent, _("refers to: %c%s at %s"),
+                            dollar_or_at, var->id, at_spec);
+          else
+            complain_at_indent (var->loc, &indent, _("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)
+            {
+              const char *format =
+                _(", cannot be accessed from mid-rule action at $%d");
+              obstack_fgrow1 (&msg_buf, format, midrule_rhs_index);
+            }
+
+	  obstack_1grow (&msg_buf, '\0');
+          if (is_warning)
+            warn_at_indent (id_loc, &indent, "%s",
+                            (char *) obstack_finish (&msg_buf));
+          else
+            complain_at_indent (id_loc, &indent, "%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
-   points to LHS ($$) of the current rule. */
+   points to LHS ($$) of the current rule or midrule. */
 #define LHS_REF (INT_MIN + 1)
 
+/* Sub-messages indent. */
+#define SUB_INDENT (4)
+
 /* Parse named or positional reference. In case of positional
    references, can return negative values for $-n "deep" stack
    accesses. */
@@ -425,10 +500,10 @@ parse_ref (char *cp, symbol_list *rule, int rule_length,
 {
   symbol_list *l;
   char *cp_end;
-  bool exact_mode;
-  bool has_error;
-  bool has_valid;
+  bool explicit_bracketing;
   unsigned i;
+  unsigned valid_variants = 0;
+  unsigned valid_variant_index = 0;
 
   if ('$' == *cp)
     return LHS_REF;
@@ -454,7 +529,7 @@ parse_ref (char *cp, symbol_list *rule, int rule_length,
 	continue;
       cp_end = p;
 
-      exact_mode = true;
+      explicit_bracketing = true;
     }
   else
     {
@@ -470,7 +545,7 @@ parse_ref (char *cp, symbol_list *rule, int rule_length,
 	continue;
       cp_end = p;
 
-      exact_mode = false;
+      explicit_bracketing = false;
     }
 
   /* Add all relevant variants. */
@@ -485,125 +560,102 @@ parse_ref (char *cp, symbol_list *rule, int rule_length,
 	  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,
-                       symbol_index, cp, cp_end, exact_mode);
+                       symbol_index, cp, cp_end, explicit_bracketing);
       }
   }
 
   /* Check errors. */
-  has_error = false;
-  has_valid = false;
   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))
-	{
-	  var->err |= VARIANT_NOT_VISIBLE_FROM_MIDRULE;
-	  has_error = true;
-	}
+        var->err |= VARIANT_NOT_VISIBLE_FROM_MIDRULE;
 
       /* 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)
-	{
-	  var->err |= VARIANT_HIDDEN;
-	  has_error = true;
-	}
+        var->err |= VARIANT_HIDDEN;
 
       if (!var->err)
-	has_valid = true;
+        {
+          valid_variant_index = i;
+          ++valid_variants;
+        }
     }
 
-  if (variant_count == 1 && has_valid)
+  switch (valid_variants)
     {
-      /* 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)
-    {
-      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);
-      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);
-	}
+    case 0:
+      {
+        unsigned len = (explicit_bracketing || !ref_tail_fields) ?
+          cp_end - cp : ref_tail_fields - cp;
+        unsigned indent = 0;
+
+        complain_at_indent (text_loc, &indent, _("invalid reference: %s"),
+                            quote (text));
+        indent += SUB_INDENT;
+        if (midrule_rhs_index)
+          {
+            const char *format =
+              _("symbol not found in production before $%d: %.*s");
+            complain_at_indent (rule->location, &indent, format,
+                                midrule_rhs_index, len, cp);
+          }
+        else
+          {
+            const char *format =
+              _("symbol not found in production: %.*s");
+            complain_at_indent (rule->location, &indent, format,
+                                len, cp);
+          }
+
+        if (variant_count > 0)
+          show_sub_messages (cp, explicit_bracketing, midrule_rhs_index,
+                             dollar_or_at, false, indent);
+        return INVALID_REF;
+      }
+    case 1:
+      {
+        unsigned indent = 0;
+        if (variant_count > 1)
+          {
+            warn_at_indent (text_loc, &indent, _("misleading reference: %s"),
+                            quote (text));
+            show_sub_messages (cp, explicit_bracketing, midrule_rhs_index,
+                               dollar_or_at, true, indent + SUB_INDENT);
+          }
+        {
+          unsigned symbol_index =
+            variant_table[valid_variant_index].symbol_index;
+          return (symbol_index == midrule_rhs_index) ? LHS_REF : symbol_index;
+        }
+      }
+    case 2:
+    default:
+      {
+        unsigned indent = 0;
+        complain_at_indent (text_loc, &indent, _("ambiguous reference: %s"),
+                            quote (text));
+        show_sub_messages (cp, explicit_bracketing, midrule_rhs_index,
+                           dollar_or_at, false, indent + SUB_INDENT);
+        return INVALID_REF;
+      }
     }
 
+  /* Not reachable. */
   return INVALID_REF;
 }