X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/aa4180418fff518198e1b0f2c43fec6432210dc7..0ced3098fd97e1483b4ac938bdce99bfc7942539:/src/scan-gram.l

diff --git a/src/scan-gram.l b/src/scan-gram.l
index 4416730c..742d54e8 100644
--- a/src/scan-gram.l
+++ b/src/scan-gram.l
@@ -182,6 +182,7 @@ splice	 (\\[ \f\t\v]*\n)*
 {
   "%binary"               return PERCENT_NONASSOC;
   "%debug"                return PERCENT_DEBUG;
+  "%default"[-_]"prec"    return PERCENT_DEFAULT_PREC;
   "%define"               return PERCENT_DEFINE;
   "%defines"              return PERCENT_DEFINES;
   "%destructor"		  token_type = PERCENT_DESTRUCTOR; BEGIN SC_PRE_CODE;
@@ -190,14 +191,17 @@ splice	 (\\[ \f\t\v]*\n)*
   "%expect"               return PERCENT_EXPECT;
   "%file-prefix"          return PERCENT_FILE_PREFIX;
   "%fixed"[-_]"output"[-_]"files"   return PERCENT_YACC;
+  "%initial-action"       token_type = PERCENT_INITIAL_ACTION; BEGIN SC_PRE_CODE;
   "%glr-parser"           return PERCENT_GLR_PARSER;
   "%left"                 return PERCENT_LEFT;
   "%lex-param"		  token_type = PERCENT_LEX_PARAM; BEGIN SC_PRE_CODE;
   "%locations"            return PERCENT_LOCATIONS;
   "%merge"		  return PERCENT_MERGE;
   "%name"[-_]"prefix"     return PERCENT_NAME_PREFIX;
+  "%no"[-_]"default"[-_]"prec"	return PERCENT_NO_DEFAULT_PREC;
   "%no"[-_]"lines"        return PERCENT_NO_LINES;
   "%nonassoc"             return PERCENT_NONASSOC;
+  "%nondeterministic-parser"   return PERCENT_NONDETERMINISTIC_PARSER;
   "%nterm"                return PERCENT_NTERM;
   "%output"               return PERCENT_OUTPUT;
   "%parse-param"	  token_type = PERCENT_PARSE_PARAM; BEGIN SC_PRE_CODE;
@@ -367,6 +371,7 @@ splice	 (\\[ \f\t\v]*\n)*
     return STRING;
   }
 
+  \0	    complain_at (*loc, _("invalid null character"));
   .|\n	    STRING_GROW;
   <<EOF>>   unexpected_eof (token_start, "\""); BEGIN INITIAL;
 }
@@ -393,6 +398,7 @@ splice	 (\\[ \f\t\v]*\n)*
     return ID;
   }
 
+  \0	    complain_at (*loc, _("invalid null character"));
   .|\n	    STRING_GROW;
   <<EOF>>   unexpected_eof (token_start, "'"); BEGIN INITIAL;
 }
@@ -408,6 +414,8 @@ splice	 (\\[ \f\t\v]*\n)*
     unsigned long c = strtoul (yytext + 1, 0, 8);
     if (UCHAR_MAX < c)
       complain_at (*loc, _("invalid escape sequence: %s"), quote (yytext));
+    else if (! c) 
+      complain_at (*loc, _("invalid null character: %s"), quote (yytext));
     else
       obstack_1grow (&obstack_for_string, c);
   }
@@ -418,6 +426,8 @@ splice	 (\\[ \f\t\v]*\n)*
     c = strtoul (yytext + 2, 0, 16);
     if (UCHAR_MAX < c || get_errno ())
       complain_at (*loc, _("invalid escape sequence: %s"), quote (yytext));
+    else if (! c)
+      complain_at (*loc, _("invalid null character: %s"), quote (yytext));
     else
       obstack_1grow (&obstack_for_string, c);
   }
@@ -437,6 +447,8 @@ splice	 (\\[ \f\t\v]*\n)*
     int c = convert_ucn_to_byte (yytext);
     if (c < 0)
       complain_at (*loc, _("invalid escape sequence: %s"), quote (yytext));
+    else if (! c)
+      complain_at (*loc, _("invalid null character: %s"), quote (yytext));
     else
       obstack_1grow (&obstack_for_string, c);
   }
@@ -648,6 +660,11 @@ splice	 (\\[ \f\t\v]*\n)*
 
 %%
 
+/* Keeps track of the maximum number of semantic values to the left of
+   a handle (those referenced by $0, $-1, etc.) are required by the
+   semantic actions of this grammar. */
+int max_left_semantic_context = 0;
+
 /* Set *LOC and adjust scanner cursor to account for token TOKEN of
    size SIZE.  */
 
@@ -780,6 +797,8 @@ handle_action_dollar (char *text, location loc)
       if (INT_MIN <= num && num <= rule_length && ! get_errno ())
 	{
 	  int n = num;
+	  if (1-n > max_left_semantic_context)
+	    max_left_semantic_context = 1-n;
 	  if (!type_name && n > 0)
 	    type_name = symbol_list_n_type_name_get (current_rule, loc, n);
 	  if (!type_name && typed)
@@ -799,10 +818,10 @@ handle_action_dollar (char *text, location loc)
 }
 
 
-/*-----------------------------------------------------------------.
-| Dispatch onto handle_action_dollar, or handle_destructor_dollar, |
-| depending upon TOKEN_TYPE.                                       |
-`-----------------------------------------------------------------*/
+/*----------------------------------------------------------------.
+| Map `$?' onto the proper M4 symbol, depending on its TOKEN_TYPE |
+| (are we in an action?).                                         |
+`----------------------------------------------------------------*/
 
 static void
 handle_dollar (int token_type, char *text, location loc)
@@ -815,6 +834,7 @@ handle_dollar (int token_type, char *text, location loc)
       break;
 
     case PERCENT_DESTRUCTOR:
+    case PERCENT_INITIAL_ACTION:
     case PERCENT_PRINTER:
       if (text[1] == '$')
 	{
@@ -840,7 +860,7 @@ static inline bool
 handle_action_at (char *text, location loc)
 {
   char *cp = text + 1;
-  locations_flag = 1;
+  locations_flag = true;
 
   if (! current_rule)
     return false;
@@ -867,10 +887,10 @@ handle_action_at (char *text, location loc)
 }
 
 
-/*-------------------------------------------------------------------.
-| Dispatch onto handle_action_at, or handle_destructor_at, depending |
-| upon CODE_KIND.                                                    |
-`-------------------------------------------------------------------*/
+/*----------------------------------------------------------------.
+| Map `@?' onto the proper M4 symbol, depending on its TOKEN_TYPE |
+| (are we in an action?).                                         |
+`----------------------------------------------------------------*/
 
 static void
 handle_at (int token_type, char *text, location loc)
@@ -881,6 +901,7 @@ handle_at (int token_type, char *text, location loc)
       handle_action_at (text, loc);
       return;
 
+    case PERCENT_INITIAL_ACTION:
     case PERCENT_DESTRUCTOR:
     case PERCENT_PRINTER:
       if (text[1] == '$')