3 * The Regents of the University of California. All rights reserved.
5 * Herbert Xu <herbert@gondor.apana.org.au>. All rights reserved.
7 * This code is derived from software contributed to Berkeley by
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34 * $FreeBSD: src/bin/sh/arith_yacc.c,v 1.5 2011/05/27 20:53:07 jilles Exp $
37 #include <sys/limits.h>
43 #include "arith_yacc.h"
52 #if ARITH_BOR + 11 != ARITH_BORASS || ARITH_ASS + 11 != ARITH_EQ
53 #error Arithmetic tokens are out of order.
56 static const char *arith_startbuf;
58 const char *arith_buf;
61 static int last_token;
63 #define ARITH_PRECEDENCE(op, prec) [op - ARITH_BINOP_MIN] = prec
65 static const char prec[ARITH_BINOP_MAX - ARITH_BINOP_MIN] = {
66 ARITH_PRECEDENCE(ARITH_MUL, 0),
67 ARITH_PRECEDENCE(ARITH_DIV, 0),
68 ARITH_PRECEDENCE(ARITH_REM, 0),
69 ARITH_PRECEDENCE(ARITH_ADD, 1),
70 ARITH_PRECEDENCE(ARITH_SUB, 1),
71 ARITH_PRECEDENCE(ARITH_LSHIFT, 2),
72 ARITH_PRECEDENCE(ARITH_RSHIFT, 2),
73 ARITH_PRECEDENCE(ARITH_LT, 3),
74 ARITH_PRECEDENCE(ARITH_LE, 3),
75 ARITH_PRECEDENCE(ARITH_GT, 3),
76 ARITH_PRECEDENCE(ARITH_GE, 3),
77 ARITH_PRECEDENCE(ARITH_EQ, 4),
78 ARITH_PRECEDENCE(ARITH_NE, 4),
79 ARITH_PRECEDENCE(ARITH_BAND, 5),
80 ARITH_PRECEDENCE(ARITH_BXOR, 6),
81 ARITH_PRECEDENCE(ARITH_BOR, 7),
84 #define ARITH_MAX_PREC 8
87 yyerror(const char *s)
89 error("arithmetic expression: %s: \"%s\"", s, arith_startbuf);
94 arith_lookupvarint(char *varname)
100 str = lookupvar(varname);
101 if (uflag && str == NULL)
102 yyerror("variable not set");
103 if (str == NULL || *str == '\0')
106 result = strtoarith_t(str, &p, 0);
107 if (errno != 0 || *p != '\0')
108 yyerror("variable conversion error");
115 return prec[op - ARITH_BINOP_MIN];
119 higher_prec(int op1, int op2)
121 return arith_prec(op1) < arith_prec(op2);
125 do_binop(int op, arith_t a, arith_t b)
133 yyerror("division by zero");
134 if (a == ARITH_MIN && b == -1)
135 yyerror("divide error");
136 return op == ARITH_REM ? a % b : a / b;
168 static arith_t assignment(int var, int noeval);
171 primary(int token, union yystype *val, int op, int noeval)
178 result = assignment(op, noeval);
179 if (last_token != ARITH_RPAREN)
180 yyerror("expecting ')'");
181 last_token = yylex();
188 return noeval ? val->val : arith_lookupvarint(val->name);
196 return -primary(op, val, yylex(), noeval);
199 return !primary(op, val, yylex(), noeval);
202 return ~primary(op, val, yylex(), noeval);
204 yyerror("expecting primary");
209 binop2(arith_t a, int op, int precedence, int noeval)
220 b = primary(token, &val, yylex(), noeval);
223 if (op2 >= ARITH_BINOP_MIN && op2 < ARITH_BINOP_MAX &&
224 higher_prec(op2, op)) {
225 b = binop2(b, op2, arith_prec(op), noeval);
229 a = noeval ? b : do_binop(op, a, b);
231 if (op2 < ARITH_BINOP_MIN || op2 >= ARITH_BINOP_MAX ||
232 arith_prec(op2) >= precedence)
240 binop(int token, union yystype *val, int op, int noeval)
242 arith_t a = primary(token, val, op, noeval);
245 if (op < ARITH_BINOP_MIN || op >= ARITH_BINOP_MAX)
248 return binop2(a, op, ARITH_MAX_PREC, noeval);
252 and(int token, union yystype *val, int op, int noeval)
254 arith_t a = binop(token, val, op, noeval);
264 b = and(token, val, yylex(), noeval | !a);
270 or(int token, union yystype *val, int op, int noeval)
272 arith_t a = and(token, val, op, noeval);
282 b = or(token, val, yylex(), noeval | !!a);
288 cond(int token, union yystype *val, int op, int noeval)
290 arith_t a = or(token, val, op, noeval);
294 if (last_token != ARITH_QMARK)
297 b = assignment(yylex(), noeval | !a);
299 if (last_token != ARITH_COLON)
300 yyerror("expecting ':'");
305 c = cond(token, val, yylex(), noeval | !!a);
311 assignment(int var, int noeval)
313 union yystype val = yylval;
316 char sresult[DIGITS(result) + 1];
318 if (var != ARITH_VAR)
319 return cond(var, &val, op, noeval);
321 if (op != ARITH_ASS && (op < ARITH_ASS_MIN || op >= ARITH_ASS_MAX))
322 return cond(var, &val, op, noeval);
324 result = assignment(yylex(), noeval);
329 result = do_binop(op - 11, arith_lookupvarint(val.name), result);
330 snprintf(sresult, sizeof(sresult), ARITH_FORMAT_STR, result);
331 setvar(val.name, sresult, 0);
338 struct stackmark smark;
341 setstackmark(&smark);
343 arith_buf = arith_startbuf = s;
345 result = assignment(yylex(), 0);
348 yyerror("expecting EOF");
350 popstackmark(&smark);
356 * The exp(1) builtin.
359 letcmd(int argc, char **argv)
370 * Concatenate arguments.
372 STARTSTACKSTR(concat);
376 STPUTC(*p++, concat);
377 if ((p = *ap++) == NULL)
381 STPUTC('\0', concat);
382 p = grabstackstr(concat);
389 out1fmt(ARITH_FORMAT_STR "\n", i);