0c8de5b03c
Among all the modifications, this new byacc also solves a 14 year old bug [1] PR: bin/23254 [1] Submitted by: marka@nominum.com [1] MFC after: 3 weeks
128 lines
2.4 KiB
Plaintext
128 lines
2.4 KiB
Plaintext
%pure-parser
|
|
|
|
%parse-param { int regs[26]
|
|
%parse-param { int *base
|
|
|
|
%lex-param { int *base
|
|
|
|
%{
|
|
# include <stdio.h>
|
|
# include <ctype.h>
|
|
|
|
#ifdef YYBISON
|
|
#define YYSTYPE int
|
|
#define YYLEX_PARAM base
|
|
#define YYLEX_DECL() yylex(YYSTYPE *yylval, int *YYLEX_PARAM)
|
|
#define YYERROR_DECL() yyerror(int regs[26], int *base, const char *s)
|
|
int YYLEX_DECL();
|
|
static void YYERROR_DECL();
|
|
#endif
|
|
|
|
%}
|
|
|
|
%start list
|
|
|
|
%token DIGIT LETTER
|
|
|
|
%left '|'
|
|
%left '&'
|
|
%left '+' '-'
|
|
%left '*' '/' '%'
|
|
%left UMINUS /* supplies precedence for unary minus */
|
|
|
|
%% /* beginning of rules section */
|
|
|
|
list : /* empty */
|
|
| list stat '\n'
|
|
| list error '\n'
|
|
{ yyerrok ; }
|
|
;
|
|
|
|
stat : expr
|
|
{ printf("%d\n",$1);}
|
|
| LETTER '=' expr
|
|
{ regs[$1] = $3; }
|
|
;
|
|
|
|
expr : '(' expr ')'
|
|
{ $$ = $2; }
|
|
| expr '+' expr
|
|
{ $$ = $1 + $3; }
|
|
| expr '-' expr
|
|
{ $$ = $1 - $3; }
|
|
| expr '*' expr
|
|
{ $$ = $1 * $3; }
|
|
| expr '/' expr
|
|
{ $$ = $1 / $3; }
|
|
| expr '%' expr
|
|
{ $$ = $1 % $3; }
|
|
| expr '&' expr
|
|
{ $$ = $1 & $3; }
|
|
| expr '|' expr
|
|
{ $$ = $1 | $3; }
|
|
| '-' expr %prec UMINUS
|
|
{ $$ = - $2; }
|
|
| LETTER
|
|
{ $$ = regs[$1]; }
|
|
| number
|
|
;
|
|
|
|
number: DIGIT
|
|
{ $$ = $1; (*base) = ($1==0) ? 8 : 10; }
|
|
| number DIGIT
|
|
{ $$ = (*base) * $1 + $2; }
|
|
;
|
|
|
|
%% /* start of programs */
|
|
|
|
#ifdef YYBYACC
|
|
extern int YYLEX_DECL();
|
|
#endif
|
|
|
|
int
|
|
main (void)
|
|
{
|
|
int regs[26];
|
|
int base = 10;
|
|
|
|
while(!feof(stdin)) {
|
|
yyparse(regs, &base);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
#define UNUSED(x) ((void)(x))
|
|
|
|
static void
|
|
YYERROR_DECL()
|
|
{
|
|
UNUSED(regs); /* %parse-param regs is not actually used here */
|
|
UNUSED(base); /* %parse-param base is not actually used here */
|
|
fprintf(stderr, "%s\n", s);
|
|
}
|
|
|
|
int
|
|
YYLEX_DECL()
|
|
{
|
|
/* lexical analysis routine */
|
|
/* returns LETTER for a lower case letter, yylval = 0 through 25 */
|
|
/* return DIGIT for a digit, yylval = 0 through 9 */
|
|
/* all other characters are returned immediately */
|
|
|
|
int c;
|
|
|
|
while( (c=getchar()) == ' ' ) { /* skip blanks */ }
|
|
|
|
/* c is now nonblank */
|
|
|
|
if( islower( c )) {
|
|
*yylval = (c - 'a');
|
|
return ( LETTER );
|
|
}
|
|
if( isdigit( c )) {
|
|
*yylval = (c - '0') % (*base);
|
|
return ( DIGIT );
|
|
}
|
|
return( c );
|
|
}
|