* data/glr.c (YYRHSLOC): Move its definition next to its uses.

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

diff --git a/src/scan-gram.l b/src/scan-gram.l
index fd384061e28bf220b66dfe839d5bad74f10502df..7541bf9f640aa45f35024201c5b818a85991fdb4 100644 (file)
--- a/src/scan-gram.l
+++ b/src/scan-gram.l
@@ -1,6 +1,6 @@
 /* Bison Grammar Scanner                             -*- C -*-
 
 /* Bison Grammar Scanner                             -*- C -*-
 

-   Copyright (C) 2002 Free Software Foundation, Inc.
+   Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.

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


@@ -20,7 +20,7 @@
    02111-1307  USA
 */
 
    02111-1307  USA
 */
 

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

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


@@ -43,6 +43,7 @@
       scanner_cursor.file = current_file;              \
       scanner_cursor.line = 1;                         \
       scanner_cursor.column = 1;                       \
       scanner_cursor.file = current_file;              \
       scanner_cursor.line = 1;                         \
       scanner_cursor.column = 1;                       \

+      code_start = scanner_cursor;                     \

     }                                                  \
   while (0)
 
     }                                                  \
   while (0)
 


@@ -97,23 +98,25 @@ scanner_last_string_free (void)
    Outside of well-formed rules, RULE_LENGTH has an undefined value.  */
 static int rule_length;
 
    Outside of well-formed rules, RULE_LENGTH has an undefined value.  */
 static int rule_length;
 

-static void handle_dollar (braced_code code_kind, char *cp, location loc);
-static void handle_at (braced_code code_kind, char *cp, location loc);
+static void handle_dollar (int token_type, char *cp, location loc);
+static void handle_at (int token_type, char *cp, location loc);

 static void handle_syncline (char *args);
 static void handle_syncline (char *args);

+static unsigned long int scan_integer (char const *p, int base, location loc);

 static int convert_ucn_to_byte (char const *hex_text);
 static int convert_ucn_to_byte (char const *hex_text);

-static void unexpected_end_of_file (boundary, char const *);
+static void unexpected_eof (boundary, char const *);
+static void unexpected_newline (boundary, char const *);

 
 %}
 %x SC_COMMENT SC_LINE_COMMENT SC_YACC_COMMENT
 %x SC_STRING SC_CHARACTER
 %x SC_AFTER_IDENTIFIER
 %x SC_ESCAPED_STRING SC_ESCAPED_CHARACTER
 
 %}
 %x SC_COMMENT SC_LINE_COMMENT SC_YACC_COMMENT
 %x SC_STRING SC_CHARACTER
 %x SC_AFTER_IDENTIFIER
 %x SC_ESCAPED_STRING SC_ESCAPED_CHARACTER

-%x SC_BRACED_CODE SC_PROLOGUE SC_EPILOGUE
+%x SC_PRE_CODE SC_BRACED_CODE SC_PROLOGUE SC_EPILOGUE

 
 letter   [.abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_]
 id       {letter}({letter}|[0-9])*
 directive %{letter}({letter}|[0-9]|-)*
 
 letter   [.abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_]
 id       {letter}({letter}|[0-9])*
 directive %{letter}({letter}|[0-9]|-)*

-int      [0-9]+
+int      [0-9]+

 
 /* POSIX says that a tag must be both an id and a C union member, but
    historically almost any character is allowed in a tag.  We disallow
 
 /* POSIX says that a tag must be both an id and a C union member, but
    historically almost any character is allowed in a tag.  We disallow


@@ -132,15 +135,20 @@ splice     (\\[ \f\t\v]*\n)*
   /* Parent context state, when applicable.  */
   int context_state IF_LINT (= 0);
 
   /* Parent context state, when applicable.  */
   int context_state IF_LINT (= 0);
 

+  /* Token type to return, when applicable.  */
+  int token_type IF_LINT (= 0);
+

   /* Location of most recent identifier, when applicable.  */
   /* Location of most recent identifier, when applicable.  */

-  location id_loc IF_LINT (= *loc);
+  location id_loc IF_LINT (= empty_location);

 
 

-  /* Where containing code started, when applicable.  */
-  boundary code_start IF_LINT (= loc->start);
+  /* Where containing code started, when applicable.  Its initial
+     value is relevant only when yylex is invoked in the SC_EPILOGUE
+     start condition.  */
+  boundary code_start = scanner_cursor;

 
   /* Where containing comment or string or character literal started,
      when applicable.  */
 
   /* Where containing comment or string or character literal started,
      when applicable.  */

-  boundary token_start IF_LINT (= loc->start);
+  boundary token_start IF_LINT (= scanner_cursor);

 %}
 
 
 %}
 
 


@@ -148,13 +156,17 @@ splice     (\\[ \f\t\v]*\n)*
   | Scanning white space.  |
   `-----------------------*/
 
   | Scanning white space.  |
   `-----------------------*/
 

-<INITIAL,SC_AFTER_IDENTIFIER>
+<INITIAL,SC_AFTER_IDENTIFIER,SC_PRE_CODE>

 {
 {

-  [ \f\n\t\v]  ;
-
-  /* Comments. */
-  "/*"         token_start = loc->start; context_state = YY_START; BEGIN SC_YACC_COMMENT;
+  /* Comments and white space.  */
+  ","         warn_at (*loc, _("stray `,' treated as white space"));
+  [ \f\n\t\v]  |

   "//".*       ;
   "//".*       ;

+  "/*" {
+    token_start = loc->start;
+    context_state = YY_START;
+    BEGIN SC_YACC_COMMENT;
+  }

 
   /* #line directives are not documented, and may be withdrawn or
      modified in future versions of Bison.  */
 
   /* #line directives are not documented, and may be withdrawn or
      modified in future versions of Bison.  */


@@ -171,36 +183,41 @@ splice     (\\[ \f\t\v]*\n)*
 {
   "%binary"               return PERCENT_NONASSOC;
   "%debug"                return PERCENT_DEBUG;
 {
   "%binary"               return PERCENT_NONASSOC;
   "%debug"                return PERCENT_DEBUG;

+  "%default"[-_]"prec"    return PERCENT_DEFAULT_PREC;

   "%define"               return PERCENT_DEFINE;
   "%defines"              return PERCENT_DEFINES;
   "%define"               return PERCENT_DEFINE;
   "%defines"              return PERCENT_DEFINES;

-  "%destructor"           return PERCENT_DESTRUCTOR;
+  "%destructor"                  token_type = PERCENT_DESTRUCTOR; BEGIN SC_PRE_CODE;

   "%dprec"               return PERCENT_DPREC;
   "%error"[-_]"verbose"   return PERCENT_ERROR_VERBOSE;
   "%expect"               return PERCENT_EXPECT;
   "%dprec"               return PERCENT_DPREC;
   "%error"[-_]"verbose"   return PERCENT_ERROR_VERBOSE;
   "%expect"               return PERCENT_EXPECT;

+  "%expect"[-_]"rr"      return PERCENT_EXPECT_RR;

   "%file-prefix"          return PERCENT_FILE_PREFIX;
   "%fixed"[-_]"output"[-_]"files"   return PERCENT_YACC;
   "%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;
   "%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;
   "%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;
   "%no"[-_]"lines"        return PERCENT_NO_LINES;
   "%nonassoc"             return PERCENT_NONASSOC;

+  "%nondeterministic-parser"   return PERCENT_NONDETERMINISTIC_PARSER;

   "%nterm"                return PERCENT_NTERM;
   "%output"               return PERCENT_OUTPUT;
   "%nterm"                return PERCENT_NTERM;
   "%output"               return PERCENT_OUTPUT;

-  "%parse-param"          return PERCENT_PARSE_PARAM;
+  "%parse-param"         token_type = PERCENT_PARSE_PARAM; BEGIN SC_PRE_CODE;

   "%prec"                 rule_length--; return PERCENT_PREC;
   "%prec"                 rule_length--; return PERCENT_PREC;

-  "%printer"              return PERCENT_PRINTER;
+  "%printer"              token_type = PERCENT_PRINTER; BEGIN SC_PRE_CODE;

   "%pure"[-_]"parser"     return PERCENT_PURE_PARSER;
   "%right"                return PERCENT_RIGHT;
   "%pure"[-_]"parser"     return PERCENT_PURE_PARSER;
   "%right"                return PERCENT_RIGHT;

-  "%lex-param"            return PERCENT_LEX_PARAM;

   "%skeleton"             return PERCENT_SKELETON;
   "%start"                return PERCENT_START;
   "%term"                 return PERCENT_TOKEN;
   "%token"                return PERCENT_TOKEN;
   "%token"[-_]"table"     return PERCENT_TOKEN_TABLE;
   "%type"                 return PERCENT_TYPE;
   "%skeleton"             return PERCENT_SKELETON;
   "%start"                return PERCENT_START;
   "%term"                 return PERCENT_TOKEN;
   "%token"                return PERCENT_TOKEN;
   "%token"[-_]"table"     return PERCENT_TOKEN_TABLE;
   "%type"                 return PERCENT_TYPE;

-  "%union"                return PERCENT_UNION;
+  "%union"               token_type = PERCENT_UNION; BEGIN SC_PRE_CODE;

   "%verbose"              return PERCENT_VERBOSE;
   "%yacc"                 return PERCENT_YACC;
 
   "%verbose"              return PERCENT_VERBOSE;
   "%yacc"                 return PERCENT_YACC;
 


@@ -212,10 +229,6 @@ splice      (\\[ \f\t\v]*\n)*
   "|"                     rule_length = 0; return PIPE;
   ";"                     return SEMICOLON;
 
   "|"                     rule_length = 0; return PIPE;
   ";"                     return SEMICOLON;
 

-  "," {
-    warn_at (*loc, _("stray `,' treated as white space"));
-  }
-

   {id} {
     val->symbol = symbol_get (yytext, *loc);
     id_loc = *loc;
   {id} {
     val->symbol = symbol_get (yytext, *loc);
     id_loc = *loc;


@@ -224,15 +237,11 @@ splice     (\\[ \f\t\v]*\n)*
   }
 
   {int} {
   }
 
   {int} {

-    unsigned long num;
-    set_errno (0);
-    num = strtoul (yytext, 0, 10);
-    if (INT_MAX < num || get_errno ())
-      {
-       complain_at (*loc, _("integer out of range: %s"), quote (yytext));
-       num = INT_MAX;
-      }
-    val->integer = num;
+    val->integer = scan_integer (yytext, 10, *loc);
+    return INT;
+  }
+  0[xX][0-9abcdefABCDEF]+ {
+    val->integer = scan_integer (yytext, 16, *loc);

     return INT;
   }
 
     return INT;
   }
 


@@ -248,6 +257,7 @@ splice       (\\[ \f\t\v]*\n)*
   /* Code in between braces.  */
   "{" {
     STRING_GROW;
   /* Code in between braces.  */
   "{" {
     STRING_GROW;

+    token_type = BRACED_CODE;

     braces_level = 0;
     code_start = loc->start;
     BEGIN SC_BRACED_CODE;
     braces_level = 0;
     code_start = loc->start;
     BEGIN SC_BRACED_CODE;


@@ -265,16 +275,18 @@ splice     (\\[ \f\t\v]*\n)*
   "%%" {
     static int percent_percent_count;
     if (++percent_percent_count == 2)
   "%%" {
     static int percent_percent_count;
     if (++percent_percent_count == 2)

-      {
-       code_start = loc->start;
-       BEGIN SC_EPILOGUE;
-      }
+      BEGIN SC_EPILOGUE;

     return PERCENT_PERCENT;
   }
 
   . {
     complain_at (*loc, _("invalid character: %s"), quote (yytext));
   }
     return PERCENT_PERCENT;
   }
 
   . {
     complain_at (*loc, _("invalid character: %s"), quote (yytext));
   }

+
+  <<EOF>> {
+    loc->start = loc->end = scanner_cursor;
+    yyterminate ();
+  }

 }
 
 
 }
 
 


@@ -313,7 +325,7 @@ splice       (\\[ \f\t\v]*\n)*
 {
   "*/"     BEGIN context_state;
   .|\n    ;
 {
   "*/"     BEGIN context_state;
   .|\n    ;

-  <<EOF>>  unexpected_end_of_file (token_start, "*/");
+  <<EOF>>  unexpected_eof (token_start, "*/"); BEGIN context_state;

 }
 
 
 }
 
 


@@ -324,7 +336,7 @@ splice       (\\[ \f\t\v]*\n)*
 <SC_COMMENT>
 {
   "*"{splice}"/"  STRING_GROW; BEGIN context_state;
 <SC_COMMENT>
 {
   "*"{splice}"/"  STRING_GROW; BEGIN context_state;

-  <<EOF>>        unexpected_end_of_file (token_start, "*/");
+  <<EOF>>        unexpected_eof (token_start, "*/"); BEGIN context_state;

 }
 
 
 }
 
 


@@ -340,10 +352,10 @@ splice     (\\[ \f\t\v]*\n)*
 }
 
 
 }
 
 

-  /*----------------------------------------------------------------.
-  | Scanning a C string, including its escapes.  The initial `"' is |
-  | already eaten.                                                  |
-  `----------------------------------------------------------------*/
+  /*------------------------------------------------.
+  | Scanning a Bison string, including its escapes. |
+  | The initial quote is already eaten.             |
+  `------------------------------------------------*/

 
 <SC_ESCAPED_STRING>
 {
 
 <SC_ESCAPED_STRING>
 {


@@ -356,15 +368,14 @@ splice     (\\[ \f\t\v]*\n)*
     BEGIN INITIAL;
     return STRING;
   }
     BEGIN INITIAL;
     return STRING;
   }

-
-  .|\n     STRING_GROW;
-  <<EOF>>   unexpected_end_of_file (token_start, "\"");
+  \n           unexpected_newline (token_start, "\""); BEGIN INITIAL;
+  <<EOF>>      unexpected_eof (token_start, "\"");     BEGIN INITIAL;

 }
 
 }
 

-  /*---------------------------------------------------------------.
-  | Scanning a C character, decoding its escapes.  The initial "'" |
-  | is already eaten.                                              |
-  `---------------------------------------------------------------*/
+  /*----------------------------------------------------------.
+  | Scanning a Bison character literal, decoding its escapes. |
+  | The initial quote is already eaten.                              |
+  `----------------------------------------------------------*/

 
 <SC_ESCAPED_CHARACTER>
 {
 
 <SC_ESCAPED_CHARACTER>
 {


@@ -382,9 +393,13 @@ splice      (\\[ \f\t\v]*\n)*
     BEGIN INITIAL;
     return ID;
   }
     BEGIN INITIAL;
     return ID;
   }

+  \n           unexpected_newline (token_start, "'");  BEGIN INITIAL;
+  <<EOF>>      unexpected_eof (token_start, "'");      BEGIN INITIAL;
+}

 
 

-  .|\n     STRING_GROW;
-  <<EOF>>   unexpected_end_of_file (token_start, "'");
+<SC_ESCAPED_CHARACTER,SC_ESCAPED_STRING>
+{
+  \0       complain_at (*loc, _("invalid null character"));

 }
 
 
 }
 
 


@@ -395,19 +410,23 @@ splice     (\\[ \f\t\v]*\n)*
 <SC_ESCAPED_STRING,SC_ESCAPED_CHARACTER>
 {
   \\[0-7]{1,3} {
 <SC_ESCAPED_STRING,SC_ESCAPED_CHARACTER>
 {
   \\[0-7]{1,3} {

-    unsigned long c = strtoul (yytext + 1, 0, 8);
+    unsigned long int c = strtoul (yytext + 1, 0, 8);

     if (UCHAR_MAX < c)
       complain_at (*loc, _("invalid escape sequence: %s"), quote (yytext));
     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);
   }
 
   \\x[0-9abcdefABCDEF]+ {
     else
       obstack_1grow (&obstack_for_string, c);
   }
 
   \\x[0-9abcdefABCDEF]+ {

-    unsigned long c;
+    unsigned long int c;

     set_errno (0);
     c = strtoul (yytext + 2, 0, 16);
     if (UCHAR_MAX < c || get_errno ())
       complain_at (*loc, _("invalid escape sequence: %s"), quote (yytext));
     set_errno (0);
     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);
   }
     else
       obstack_1grow (&obstack_for_string, c);
   }


@@ -427,6 +446,8 @@ splice       (\\[ \f\t\v]*\n)*
     int c = convert_ucn_to_byte (yytext);
     if (c < 0)
       complain_at (*loc, _("invalid escape sequence: %s"), quote (yytext));
     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);
   }
     else
       obstack_1grow (&obstack_for_string, c);
   }


@@ -436,30 +457,27 @@ splice     (\\[ \f\t\v]*\n)*
   }
 }
 
   }
 }
 

+  /*--------------------------------------------.
+  | Scanning user-code characters and strings.  |
+  `--------------------------------------------*/

 
 

-  /*----------------------------------------------------------.
-  | Scanning a C character without decoding its escapes.  The |
-  | initial "'" is already eaten.                             |
-  `----------------------------------------------------------*/
+<SC_CHARACTER,SC_STRING>
+{
+  {splice}|\\{splice}[^\n$@\[\]]       STRING_GROW;
+}

 
 <SC_CHARACTER>
 {
 
 <SC_CHARACTER>
 {

-  "'"                  STRING_GROW; BEGIN context_state;
-  \\{splice}[^$@\[\]]  STRING_GROW;
-  <<EOF>>              unexpected_end_of_file (token_start, "'");
+  "'"          STRING_GROW; BEGIN context_state;
+  \n           unexpected_newline (token_start, "'"); BEGIN context_state;
+  <<EOF>>      unexpected_eof (token_start, "'"); BEGIN context_state;

 }
 
 }
 

-
-  /*----------------------------------------------------------------.
-  | Scanning a C string, without decoding its escapes.  The initial |
-  | `"' is already eaten.                                           |
-  `----------------------------------------------------------------*/
-

 <SC_STRING>
 {
 <SC_STRING>
 {

-  "\""                 STRING_GROW; BEGIN context_state;
-  \\{splice}[^$@\[\]]  STRING_GROW;
-  <<EOF>>              unexpected_end_of_file (token_start, "\"");
+  "\""         STRING_GROW; BEGIN context_state;
+  \n           unexpected_newline (token_start, "\""); BEGIN context_state;
+  <<EOF>>      unexpected_eof (token_start, "\""); BEGIN context_state;

 }
 
 
 }
 
 


@@ -495,6 +513,41 @@ splice      (\\[ \f\t\v]*\n)*
 }
 
 
 }
 
 

+  /*---------------------------------------------------------------.
+  | Scanning after %union etc., possibly followed by white space.  |
+  | For %union only, allow arbitrary C code to appear before the   |
+  | following brace, as an extension to POSIX.                    |
+  `---------------------------------------------------------------*/
+
+<SC_PRE_CODE>
+{
+  . {
+    bool valid = yytext[0] == '{' || token_type == PERCENT_UNION;
+    scanner_cursor.column -= mbsnwidth (yytext, yyleng, 0);
+    yyless (0);
+
+    if (valid)
+      {
+       braces_level = -1;
+       code_start = loc->start;
+       BEGIN SC_BRACED_CODE;
+      }
+    else
+      {
+       complain_at (*loc, _("missing `{' in `%s'"),
+                    token_name (token_type));
+       obstack_sgrow (&obstack_for_string, "{}");
+       STRING_FINISH;
+       val->chars = last_string;
+       BEGIN INITIAL;
+       return token_type;
+      }
+  }
+
+  <<EOF>>  unexpected_eof (scanner_cursor, "{}"); BEGIN INITIAL;
+}
+
+

   /*---------------------------------------------------------------.
   | Scanning some code in braces (%union and actions). The initial |
   | "{" is already eaten.                                          |
   /*---------------------------------------------------------------.
   | Scanning some code in braces (%union and actions). The initial |
   | "{" is already eaten.                                          |


@@ -505,16 +558,35 @@ splice     (\\[ \f\t\v]*\n)*
   "{"|"<"{splice}"%"  STRING_GROW; braces_level++;
   "%"{splice}">"      STRING_GROW; braces_level--;
   "}" {
   "{"|"<"{splice}"%"  STRING_GROW; braces_level++;
   "%"{splice}">"      STRING_GROW; braces_level--;
   "}" {

-    STRING_GROW;
-    braces_level--;
-    if (braces_level < 0)
+    bool outer_brace = --braces_level < 0;
+
+    /* As an undocumented Bison extension, append `;' before the last
+       brace in braced code, so that the user code can omit trailing
+       `;'.  But do not append `;' if emulating Yacc, since Yacc does
+       not append one.
+
+       FIXME: Bison should warn if a semicolon seems to be necessary
+       here, and should omit the semicolon if it seems unnecessary
+       (e.g., after ';', '{', or '}', each followed by comments or
+       white space).  Such a warning shouldn't depend on --yacc; it
+       should depend on a new --pedantic option, which would cause
+       Bison to warn if it detects an extension to POSIX.  --pedantic
+       should also diagnose other Bison extensions like %yacc.
+       Perhaps there should also be a GCC-style --pedantic-errors
+       option, so that such warnings are diagnosed as errors.  */
+    if (outer_brace && token_type == BRACED_CODE && ! yacc_flag)
+      obstack_1grow (&obstack_for_string, ';');
+
+    obstack_1grow (&obstack_for_string, '}');
+
+    if (outer_brace)

       {
        STRING_FINISH;
       {
        STRING_FINISH;

+       rule_length++;

        loc->start = code_start;
        val->chars = last_string;
        loc->start = code_start;
        val->chars = last_string;

-       rule_length++;

        BEGIN INITIAL;
        BEGIN INITIAL;

-       return BRACED_CODE;
+       return token_type;

       }
   }
 
       }
   }
 


@@ -522,12 +594,10 @@ splice     (\\[ \f\t\v]*\n)*
      (as `<' `<%').  */
   "<"{splice}"<"  STRING_GROW;
 
      (as `<' `<%').  */
   "<"{splice}"<"  STRING_GROW;
 

-  "$"("<"{tag}">")?(-?[0-9]+|"$") { handle_dollar (current_braced_code,
-                                                  yytext, *loc); }
-  "@"(-?[0-9]+|"$")               { handle_at (current_braced_code,
-                                              yytext, *loc); }
+  "$"("<"{tag}">")?(-?[0-9]+|"$")  handle_dollar (token_type, yytext, *loc);
+  "@"(-?[0-9]+|"$")               handle_at (token_type, yytext, *loc);

 
 

-  <<EOF>>  unexpected_end_of_file (code_start, "}");
+  <<EOF>>  unexpected_eof (code_start, "}"); BEGIN INITIAL;

 }
 
 
 }
 
 


@@ -545,7 +615,7 @@ splice       (\\[ \f\t\v]*\n)*
     return PROLOGUE;
   }
 
     return PROLOGUE;
   }
 

-  <<EOF>>  unexpected_end_of_file (code_start, "%}");
+  <<EOF>>  unexpected_eof (code_start, "%}"); BEGIN INITIAL;

 }
 
 
 }
 
 


@@ -566,10 +636,9 @@ splice      (\\[ \f\t\v]*\n)*
 }
 
 
 }
 
 

-  /*----------------------------------------------------------------.
-  | By default, grow the string obstack with the input, escaping M4 |
-  | quoting characters.                                                    |
-  `----------------------------------------------------------------*/
+  /*-----------------------------------------.
+  | Escape M4 quoting characters in C code.  |
+  `-----------------------------------------*/

 
 <SC_COMMENT,SC_LINE_COMMENT,SC_STRING,SC_CHARACTER,SC_BRACED_CODE,SC_PROLOGUE,SC_EPILOGUE>
 {
 
 <SC_COMMENT,SC_LINE_COMMENT,SC_STRING,SC_CHARACTER,SC_BRACED_CODE,SC_PROLOGUE,SC_EPILOGUE>
 {


@@ -577,12 +646,23 @@ splice     (\\[ \f\t\v]*\n)*
   \@   obstack_sgrow (&obstack_for_string, "@@");
   \[   obstack_sgrow (&obstack_for_string, "@{");
   \]   obstack_sgrow (&obstack_for_string, "@}");
   \@   obstack_sgrow (&obstack_for_string, "@@");
   \[   obstack_sgrow (&obstack_for_string, "@{");
   \]   obstack_sgrow (&obstack_for_string, "@}");

-  .|\n  STRING_GROW;

 }
 
 
 }
 
 

+  /*-----------------------------------------------------.
+  | By default, grow the string obstack with the input.  |
+  `-----------------------------------------------------*/
+
+<SC_COMMENT,SC_LINE_COMMENT,SC_BRACED_CODE,SC_PROLOGUE,SC_EPILOGUE,SC_STRING,SC_CHARACTER,SC_ESCAPED_STRING,SC_ESCAPED_CHARACTER>.     |
+<SC_COMMENT,SC_LINE_COMMENT,SC_BRACED_CODE,SC_PROLOGUE,SC_EPILOGUE>\n  STRING_GROW;
+

 %%
 
 %%
 

+/* 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.  */
 
 /* Set *LOC and adjust scanner cursor to account for token TOKEN of
    size SIZE.  */
 


@@ -627,14 +707,14 @@ adjust_location (location *loc, char const *token, size_t size)
 static size_t
 no_cr_read (FILE *fp, char *buf, size_t size)
 {
 static size_t
 no_cr_read (FILE *fp, char *buf, size_t size)
 {

-  size_t s = fread (buf, 1, size, fp);
-  if (s)
+  size_t bytes_read = fread (buf, 1, size, fp);
+  if (bytes_read)

     {
     {

-      char *w = memchr (buf, '\r', s);
+      char *w = memchr (buf, '\r', bytes_read);

       if (w)
        {
          char const *r = ++w;
       if (w)
        {
          char const *r = ++w;

-         char const *lim = buf + s;
+         char const *lim = buf + bytes_read;

 
          for (;;)
            {
 
          for (;;)
            {


@@ -663,7 +743,7 @@ no_cr_read (FILE *fp, char *buf, size_t size)
        }
     }
 
        }
     }
 

-  return s;
+  return bytes_read;

 }
 
 
 }
 
 


@@ -675,12 +755,15 @@ no_cr_read (FILE *fp, char *buf, size_t size)
 | Output to OBSTACK_FOR_STRING a reference to this semantic value.  |
 `------------------------------------------------------------------*/
 
 | Output to OBSTACK_FOR_STRING a reference to this semantic value.  |
 `------------------------------------------------------------------*/
 

-static inline void
+static inline bool

 handle_action_dollar (char *text, location loc)
 {
   const char *type_name = NULL;
   char *cp = text + 1;
 
 handle_action_dollar (char *text, location loc)
 {
   const char *type_name = NULL;
   char *cp = text + 1;
 

+  if (! current_rule)
+    return false;
+

   /* Get the type name if explicit. */
   if (*cp == '<')
     {
   /* Get the type name if explicit. */
   if (*cp == '<')
     {


@@ -705,13 +788,15 @@ handle_action_dollar (char *text, location loc)
     }
   else
     {
     }
   else
     {

-      long num;
+      long int num;

       set_errno (0);
       num = strtol (cp, 0, 10);
 
       if (INT_MIN <= num && num <= rule_length && ! get_errno ())
        {
          int n = num;
       set_errno (0);
       num = strtol (cp, 0, 10);
 
       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)
          if (!type_name && n > 0)
            type_name = symbol_list_n_type_name_get (current_rule, loc, n);
          if (!type_name && typed)


@@ -726,44 +811,41 @@ handle_action_dollar (char *text, location loc)
       else
        complain_at (loc, _("integer out of range: %s"), quote (text));
     }
       else
        complain_at (loc, _("integer out of range: %s"), quote (text));
     }

-}
-

 
 

-/*---------------------------------------------------------------.
-| TEXT is expected to be $$ in some code associated to a symbol: |
-| destructor or printer.                                         |
-`---------------------------------------------------------------*/
-
-static inline void
-handle_symbol_code_dollar (char *text, location loc)
-{
-  char *cp = text + 1;
-  if (*cp == '$')
-    obstack_sgrow (&obstack_for_string, "]b4_dollar_dollar[");
-  else
-    complain_at (loc, _("invalid value: %s"), quote (text));
+  return true;

 }
 
 
 }
 
 

-/*-----------------------------------------------------------------.
-| Dispatch onto handle_action_dollar, or handle_destructor_dollar, |
-| depending upon CODE_KIND.                                        |
-`-----------------------------------------------------------------*/
+/*----------------------------------------------------------------.
+| Map `$?' onto the proper M4 symbol, depending on its TOKEN_TYPE |
+| (are we in an action?).                                         |
+`----------------------------------------------------------------*/

 
 static void
 
 static void

-handle_dollar (braced_code braced_code_kind, char *text, location loc)
+handle_dollar (int token_type, char *text, location loc)

 {
 {

-  switch (braced_code_kind)
+  switch (token_type)

     {
     {

-    case action_braced_code:
-      handle_action_dollar (text, loc);
+    case BRACED_CODE:
+      if (handle_action_dollar (text, loc))
+       return;
+      break;
+
+    case PERCENT_DESTRUCTOR:
+    case PERCENT_INITIAL_ACTION:
+    case PERCENT_PRINTER:
+      if (text[1] == '$')
+       {
+         obstack_sgrow (&obstack_for_string, "]b4_dollar_dollar[");
+         return;
+       }

       break;
 
       break;
 

-    case destructor_braced_code:
-    case printer_braced_code:
-      handle_symbol_code_dollar (text, loc);
+    default:

       break;
     }
       break;
     }

+
+  complain_at (loc, _("invalid value: %s"), quote (text));

 }
 
 
 }
 
 


@@ -772,19 +854,20 @@ handle_dollar (braced_code braced_code_kind, char *text, location loc)
 | OBSTACK_FOR_STRING a reference to this location.      |
 `------------------------------------------------------*/
 
 | OBSTACK_FOR_STRING a reference to this location.      |
 `------------------------------------------------------*/
 

-static inline void
+static inline bool

 handle_action_at (char *text, location loc)
 {
   char *cp = text + 1;
 handle_action_at (char *text, location loc)
 {
   char *cp = text + 1;

-  locations_flag = 1;
+  locations_flag = true;
+
+  if (! current_rule)
+    return false;

 
   if (*cp == '$')
 
   if (*cp == '$')

-    {
-      obstack_sgrow (&obstack_for_string, "]b4_lhs_location[");
-    }
+    obstack_sgrow (&obstack_for_string, "]b4_lhs_location[");

   else
     {
   else
     {

-      long num;
+      long int num;

       set_errno (0);
       num = strtol (cp, 0, 10);
 
       set_errno (0);
       num = strtol (cp, 0, 10);
 


@@ -797,44 +880,59 @@ handle_action_at (char *text, location loc)
       else
        complain_at (loc, _("integer out of range: %s"), quote (text));
     }
       else
        complain_at (loc, _("integer out of range: %s"), quote (text));
     }

-}
-
-
-/*---------------------------------------------------------------.
-| TEXT is expected to be @$ in some code associated to a symbol: |
-| destructor or printer.                                         |
-`---------------------------------------------------------------*/

 
 

-static inline void
-handle_symbol_code_at (char *text, location loc)
-{
-  char *cp = text + 1;
-  if (*cp == '$')
-    obstack_sgrow (&obstack_for_string, "]b4_at_dollar[");
-  else
-    complain_at (loc, _("invalid value: %s"), quote (text));
+  return true;

 }
 
 
 }
 
 

-/*-------------------------------------------------------------------.
-| 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
 
 static void

-handle_at (braced_code braced_code_kind, char *text, location loc)
+handle_at (int token_type, char *text, location loc)

 {
 {

-  switch (braced_code_kind)
+  switch (token_type)

     {
     {

-    case action_braced_code:
+    case BRACED_CODE:

       handle_action_at (text, loc);
       handle_action_at (text, loc);

+      return;
+
+    case PERCENT_INITIAL_ACTION:
+    case PERCENT_DESTRUCTOR:
+    case PERCENT_PRINTER:
+      if (text[1] == '$')
+       {
+         obstack_sgrow (&obstack_for_string, "]b4_at_dollar[");
+         return;
+       }

       break;
 
       break;
 

-    case destructor_braced_code:
-    case printer_braced_code:
-      handle_symbol_code_at (text, loc);
+    default:

       break;
     }
       break;
     }

+
+  complain_at (loc, _("invalid value: %s"), quote (text));
+}
+
+
+/*------------------------------------------------------.
+| Scan NUMBER for a base-BASE integer at location LOC.  |
+`------------------------------------------------------*/
+
+static unsigned long int
+scan_integer (char const *number, int base, location loc)
+{
+  unsigned long int num;
+  set_errno (0);
+  num = strtoul (number, 0, base);
+  if (INT_MAX < num || get_errno ())
+    {
+      complain_at (loc, _("integer out of range: %s"), quote (number));
+      num = INT_MAX;
+    }
+  return num;

 }
 
 
 }
 
 


@@ -847,7 +945,7 @@ handle_at (braced_code braced_code_kind, char *text, location loc)
 static int
 convert_ucn_to_byte (char const *ucn)
 {
 static int
 convert_ucn_to_byte (char const *ucn)
 {

-  unsigned long code = strtoul (ucn + 2, 0, 16);
+  unsigned long int code = strtoul (ucn + 2, 0, 16);

 
   /* FIXME: Currently we assume Unicode-compatible unibyte characters
      on ASCII hosts (i.e., Latin-1 on hosts with 8-bit bytes).  On
 
   /* FIXME: Currently we assume Unicode-compatible unibyte characters
      on ASCII hosts (i.e., Latin-1 on hosts with 8-bit bytes).  On


@@ -905,34 +1003,48 @@ handle_syncline (char *args)
   const char *file = NULL;
   file = strchr (args, '"') + 1;
   *strchr (file, '"') = 0;
   const char *file = NULL;
   file = strchr (args, '"') + 1;
   *strchr (file, '"') = 0;

-  scanner_cursor.file = current_file = xstrdup (file);
+  scanner_cursor.file = current_file = uniqstr_new (file);

   scanner_cursor.line = lineno;
   scanner_cursor.column = 1;
 }
 
 
   scanner_cursor.line = lineno;
   scanner_cursor.column = 1;
 }
 
 

+/*----------------------------------------------------------------.
+| For a token or comment starting at START, report message MSGID, |
+| which should say that an end marker was found before           |
+| the expected TOKEN_END.                                        |
+`----------------------------------------------------------------*/
+
+static void
+unexpected_end (boundary start, char const *msgid, char const *token_end)
+{
+  location loc;
+  loc.start = start;
+  loc.end = scanner_cursor;
+  complain_at (loc, _(msgid), token_end);
+}
+
+

 /*------------------------------------------------------------------------.
 | Report an unexpected EOF in a token or comment starting at START.       |
 | An end of file was encountered and the expected TOKEN_END was missing.  |
 /*------------------------------------------------------------------------.
 | Report an unexpected EOF in a token or comment starting at START.       |
 | An end of file was encountered and the expected TOKEN_END was missing.  |

-| After reporting the problem, pretend that TOKEN_END was found.          |

 `------------------------------------------------------------------------*/
 
 static void
 `------------------------------------------------------------------------*/
 
 static void

-unexpected_end_of_file (boundary start, char const *token_end)
+unexpected_eof (boundary start, char const *token_end)

 {
 {

-  size_t i = strlen (token_end);
+  unexpected_end (start, N_("missing `%s' at end of file"), token_end);
+}

 
 

-  location loc;
-  loc.start = start;
-  loc.end = scanner_cursor;
-  complain_at (loc, _("missing `%s' at end of file"), token_end);

 
 

-  /* Adjust scanner cursor so that any later message does not count
-     the characters about to be inserted.  */
-  scanner_cursor.column -= i;
+/*----------------------------------------.
+| Likewise, but for unexpected newlines.  |
+`----------------------------------------*/

 
 

-  while (i != 0)
-    unput (token_end[--i]);
+static void
+unexpected_newline (boundary start, char const *token_end)
+{
+  unexpected_end (start, N_("missing `%s' at end of line"), token_end);

 }
 
 
 }