minix/external/bsd/byacc/dist/test/calc.y
Lionel Sambuc 84d9c625bf Synchronize on NetBSD-CVS (2013/12/1 12:00:00 UTC)
- Fix for possible unset uid/gid in toproto
 - Fix for default mtree style
 - Update libelf
 - Importing libexecinfo
 - Resynchronize GCC, mpc, gmp, mpfr
 - build.sh: Replace params with show-params.
     This has been done as the make target has been renamed in the same
     way, while a new target named params has been added. This new
     target generates a file containing all the parameters, instead of
     printing it on the console.
 - Update test48 with new etc/services (Fix by Ben Gras <ben@minix3.org)
     get getservbyport() out of the inner loop

Change-Id: Ie6ad5226fa2621ff9f0dee8782ea48f9443d2091
2014-07-28 17:05:06 +02:00

108 lines
1.9 KiB
Text

/* $NetBSD: calc.y,v 1.1.1.5 2013/04/06 14:45:27 christos Exp $ */
%{
# include <stdio.h>
# include <ctype.h>
int regs[26];
int base;
extern int yylex(void);
static void yyerror(const char *s);
%}
%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 */
int
main (void)
{
while(!feof(stdin)) {
yyparse();
}
return 0;
}
static void
yyerror(const char *s)
{
fprintf(stderr, "%s\n", s);
}
int
yylex(void)
{
/* 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';
return ( DIGIT );
}
return( c );
}