xref: /netbsd-src/external/bsd/flex/dist/tests/bison_yylval_parser.y (revision 56bd85463476f90bb489799c99292bb30d6771c0)
1 /*
2  * This file is part of flex.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * Neither the name of the University nor the names of its contributors
15  * may be used to endorse or promote products derived from this software
16  * without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
19  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
20  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
21  * PURPOSE.
22  */
23 
24 /* Accepts html-like input.
25    How to compile:
26    bison --defines --output-file="parser.c" --name-prefix="test" parser.y
27  */
28 %parse-param { void* scanner }
29 %lex-param { void* scanner }
30 %{
31 #include <stdio.h>
32 #include <stdlib.h>
33 #include <string.h>
34 #include "config.h"
35 #include "bison_yylval_parser.h"
36 #include "bison_yylval_scanner.h"
37 
38 #define YYERROR_VERBOSE 1
39 
40 int yyerror(void* scanner, const char* msg);
41 
42 /* A dummy function. A check against seg-faults in yylval->str. */
process_text(char * s)43 static int process_text(char* s) {
44     int total =0;
45     while(*s) {
46         total += (int) *s;
47         ++s;
48     }
49     return total;
50 }
51 
52 
53 %}
54 
55 %pure-parser
56 
57 %union  {
58     long unused;
59     char * str;
60 }
61 
62 %token <str> TAGNAME TEXT
63 %token  LT
64 %token  GT
65 %token  LTSLASH "</"
66 
67 %%
68 
69 html:
70     TEXT { process_text($1); free($1);}
71   | starttag html endtag
72   | html TEXT { process_text($2); free($2);}
73   | html starttag html endtag
74   ;
75 
76 starttag:  LT      TAGNAME GT { process_text($2); free($2);} ;
77 endtag:    LTSLASH TAGNAME GT { process_text($2);free($2);} ;
78 %%
79 
80 int yyerror(void* scanner, const char* msg) {
81     (void)scanner;
82     fprintf(stderr,"%s\n",msg);
83     return 0;
84 }
85