xref: /freebsd/contrib/byacc/test/err_syntax27.y (revision d6b92ffa)
1 %pure-parser
2 
3 %parse-param { int regs[26]
4 %parse-param { int *base
5 
6 %lex-param { int *base
7 
8 %{
9 # include <stdio.h>
10 # include <ctype.h>
11 
12 #ifdef YYBISON
13 #define YYSTYPE int
14 #define YYLEX_PARAM base
15 #define YYLEX_DECL() yylex(YYSTYPE *yylval, int *YYLEX_PARAM)
16 #define YYERROR_DECL() yyerror(int regs[26], int *base, const char *s)
17 int YYLEX_DECL();
18 static void YYERROR_DECL();
19 #endif
20 
21 %}
22 
23 %start list
24 
25 %token DIGIT LETTER
26 
27 %left '|'
28 %left '&'
29 %left '+' '-'
30 %left '*' '/' '%'
31 %left UMINUS   /* supplies precedence for unary minus */
32 
33 %% /* beginning of rules section */
34 
35 list  :  /* empty */
36       |  list stat '\n'
37       |  list error '\n'
38             {  yyerrok ; }
39       ;
40 
41 stat  :  expr
42             {  printf("%d\n",$1);}
43       |  LETTER '=' expr
44             {  regs[$1] = $3; }
45       ;
46 
47 expr  :  '(' expr ')'
48             {  $$ = $2; }
49       |  expr '+' expr
50             {  $$ = $1 + $3; }
51       |  expr '-' expr
52             {  $$ = $1 - $3; }
53       |  expr '*' expr
54             {  $$ = $1 * $3; }
55       |  expr '/' expr
56             {  $$ = $1 / $3; }
57       |  expr '%' expr
58             {  $$ = $1 % $3; }
59       |  expr '&' expr
60             {  $$ = $1 & $3; }
61       |  expr '|' expr
62             {  $$ = $1 | $3; }
63       |  '-' expr %prec UMINUS
64             {  $$ = - $2; }
65       |  LETTER
66             {  $$ = regs[$1]; }
67       |  number
68       ;
69 
70 number:  DIGIT
71          {  $$ = $1; (*base) = ($1==0) ? 8 : 10; }
72       |  number DIGIT
73          {  $$ = (*base) * $1 + $2; }
74       ;
75 
76 %% /* start of programs */
77 
78 #ifdef YYBYACC
79 extern int YYLEX_DECL();
80 #endif
81 
82 int
83 main (void)
84 {
85     int regs[26];
86     int base = 10;
87 
88     while(!feof(stdin)) {
89 	yyparse(regs, &base);
90     }
91     return 0;
92 }
93 
94 #define UNUSED(x) ((void)(x))
95 
96 static void
97 YYERROR_DECL()
98 {
99     UNUSED(regs); /* %parse-param regs is not actually used here */
100     UNUSED(base); /* %parse-param base is not actually used here */
101     fprintf(stderr, "%s\n", s);
102 }
103 
104 int
105 YYLEX_DECL()
106 {
107 	/* lexical analysis routine */
108 	/* returns LETTER for a lower case letter, yylval = 0 through 25 */
109 	/* return DIGIT for a digit, yylval = 0 through 9 */
110 	/* all other characters are returned immediately */
111 
112     int c;
113 
114     while( (c=getchar()) == ' ' )   { /* skip blanks */ }
115 
116     /* c is now nonblank */
117 
118     if( islower( c )) {
119 	*yylval = (c - 'a');
120 	return ( LETTER );
121     }
122     if( isdigit( c )) {
123 	*yylval = (c - '0') % (*base);
124 	return ( DIGIT );
125     }
126     return( c );
127 }
128