doc: one of the fixes for an ambiguous grammar was ambiguous too

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

diff --git a/src/scan-code.l b/src/scan-code.l
index 31b4429816eec908d3a897a2295a7acb2a339fb7..fa593beb8da889aeeb3c9685dacf0497f7422508 100644 (file)
--- a/src/scan-code.l
+++ b/src/scan-code.l
@@ -103,7 +103,10 @@ ref      -?[0-9]+|{id}|"["{id}"]"|"$"
      ';', or a C preprocessor directive, and that whitespaces and
      comments do not affect this flag.  Note that '{' does not need a
      semicolon because of '{}'.  A semicolon may be needed before a
-     cpp directive, but don't bother.  */
+     cpp directive, but don't bother.
+
+     While it is maintained in several start-conditions (factoring
+     opportunities), it is meaningful only for SC_RULE_ACTION. */
   bool need_semicolon = false;
 
   /* Whether in a C preprocessor directive.  Don't use a start condition
@@ -181,6 +184,15 @@ ref      -?[0-9]+|{id}|"["{id}"]"|"$"
     STRING_GROW;
     BEGIN SC_LINE_COMMENT;
   }
+  [$@]  {
+    warn_at (*loc, _("stray '%s'"), yytext);
+    obstack_escape (&obstack_for_string, yytext);
+    need_semicolon = true;
+  }
+  [\[\]]  {
+    obstack_escape (&obstack_for_string, yytext);
+    need_semicolon = true;
+  }
 }
 
 <SC_RULE_ACTION>
@@ -199,24 +211,6 @@ ref      -?[0-9]+|{id}|"["{id}"]"|"$"
       obstack_sgrow (&obstack_for_string, ref_tail_fields);
     need_semicolon = true;
   }
-  "$"  {
-    warn_at (*loc, _("stray '$'"));
-    obstack_sgrow (&obstack_for_string, "$][");
-    need_semicolon = true;
-  }
-  "@"  {
-    warn_at (*loc, _("stray '@'"));
-    obstack_sgrow (&obstack_for_string, "@@");
-    need_semicolon = true;
-  }
-  "["  {
-    obstack_sgrow (&obstack_for_string, "@{");
-    need_semicolon = true;
-  }
-  "]"  {
-    obstack_sgrow (&obstack_for_string, "@}");
-    need_semicolon = true;
-  }
 
   ";"  STRING_GROW;                 need_semicolon = false;
   "{"  STRING_GROW; ++braces_level; need_semicolon = false;
@@ -281,29 +275,17 @@ ref      -?[0-9]+|{id}|"["{id}"]"|"$"
 }
 
 
-  /*-----------------------------------------.
-  | Escape M4 quoting characters in C code.  |
-  `-----------------------------------------*/
-
 <*>
 {
-  \$   obstack_sgrow (&obstack_for_string, "$][");
-  \@   obstack_sgrow (&obstack_for_string, "@@");
-  \[   obstack_sgrow (&obstack_for_string, "@{");
-  \]   obstack_sgrow (&obstack_for_string, "@}");
-}
+  /* Escape M4 quoting characters in C code.  */
+  [$@\[\]]    obstack_escape (&obstack_for_string, yytext);
 
-  /*-----------------------------------------------------.
-  | By default, grow the string obstack with the input.  |
-  `-----------------------------------------------------*/
+  /* By default, grow the string obstack with the input.  */
+  .|\n        STRING_GROW;
 
-<*>.|\n        STRING_GROW;
-
- /* End of processing. */
-<*><<EOF>>      {
-                   STRING_FINISH;
-                   return last_string;
-                 }
+  /* End of processing. */
+  <<EOF>>     STRING_FINISH; return last_string;
+}
 
 %%
 
@@ -461,30 +443,30 @@ show_sub_messages (const char* cp, bool explicit_bracketing,
          /* Create the explanation message. */
          obstack_init (&msg_buf);
 
-         obstack_fgrow1 (&msg_buf, _("possibly meant: %c"), dollar_or_at);
+         obstack_printf (&msg_buf, _("possibly meant: %c"), dollar_or_at);
          if (contains_dot_or_dash (id))
-           obstack_fgrow1 (&msg_buf, "[%s]", id);
+           obstack_printf (&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);
+             obstack_printf (&msg_buf, _(", hiding %c"), dollar_or_at);
              if (contains_dot_or_dash (var->id))
-               obstack_fgrow1 (&msg_buf, "[%s]", var->id);
+               obstack_printf (&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);
+         obstack_printf (&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_printf (&msg_buf, format, midrule_rhs_index);
             }
 
          obstack_1grow (&msg_buf, '\0');
@@ -806,7 +788,7 @@ handle_action_dollar (symbol_list *rule, char *text, location dollar_loc)
             untyped_var_seen = true;
         }
 
-      obstack_fgrow2 (&obstack_for_string,
+      obstack_printf (&obstack_for_string,
                      "]b4_rhs_value(%d, %d, ", effective_rule_length, n);
       obstack_quote (&obstack_for_string, type_name);
       obstack_sgrow (&obstack_for_string, ")[");
@@ -856,7 +838,7 @@ handle_action_at (symbol_list *rule, char *text, location at_loc)
       break;
 
     default:
-      obstack_fgrow2 (&obstack_for_string, "]b4_rhs_location(%d, %d)[",
+      obstack_printf (&obstack_for_string, "]b4_rhs_location(%d, %d)[",
                      effective_rule_length, n);
       break;
     }