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 1.3 2011/03/05 13:27:13 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 (str == NULL || *str == '\0')
104 result = strtoarith_t(str, &p, 0);
105 if (errno != 0 || *p != '\0')
106 yyerror("variable conversion error");
113 return prec[op - ARITH_BINOP_MIN];
117 higher_prec(int op1, int op2)
119 return arith_prec(op1) < arith_prec(op2);
123 do_binop(int op, arith_t a, arith_t b)
131 yyerror("division by zero");
132 if (a == ARITH_MIN && b == -1)
133 yyerror("divide error");
134 return op == ARITH_REM ? a % b : a / b;
166 static arith_t assignment(int var, int noeval);
169 primary(int token, union yystype *val, int op, int noeval)
176 result = assignment(op, noeval);
177 if (last_token != ARITH_RPAREN)
178 yyerror("expecting ')'");
179 last_token = yylex();
186 return noeval ? val->val : arith_lookupvarint(val->name);
194 return -primary(op, val, yylex(), noeval);
197 return !primary(op, val, yylex(), noeval);
200 return ~primary(op, val, yylex(), noeval);
202 yyerror("expecting primary");
207 binop2(arith_t a, int op, int precedence, int noeval)
218 b = primary(token, &val, yylex(), noeval);
221 if (op2 >= ARITH_BINOP_MIN && op2 < ARITH_BINOP_MAX &&
222 higher_prec(op2, op)) {
223 b = binop2(b, op2, arith_prec(op), noeval);
227 a = noeval ? b : do_binop(op, a, b);
229 if (op2 < ARITH_BINOP_MIN || op2 >= ARITH_BINOP_MAX ||
230 arith_prec(op2) >= precedence)
238 binop(int token, union yystype *val, int op, int noeval)
240 arith_t a = primary(token, val, op, noeval);
243 if (op < ARITH_BINOP_MIN || op >= ARITH_BINOP_MAX)
246 return binop2(a, op, ARITH_MAX_PREC, noeval);
250 and(int token, union yystype *val, int op, int noeval)
252 arith_t a = binop(token, val, op, noeval);
262 b = and(token, val, yylex(), noeval | !a);
268 or(int token, union yystype *val, int op, int noeval)
270 arith_t a = and(token, val, op, noeval);
280 b = or(token, val, yylex(), noeval | !!a);
286 cond(int token, union yystype *val, int op, int noeval)
288 arith_t a = or(token, val, op, noeval);
292 if (last_token != ARITH_QMARK)
295 b = assignment(yylex(), noeval | !a);
297 if (last_token != ARITH_COLON)
298 yyerror("expecting ':'");
303 c = cond(token, val, yylex(), noeval | !!a);
309 assignment(int var, int noeval)
311 union yystype val = yylval;
314 char sresult[DIGITS(result) + 1];
316 if (var != ARITH_VAR)
317 return cond(var, &val, op, noeval);
319 if (op != ARITH_ASS && (op < ARITH_ASS_MIN || op >= ARITH_ASS_MAX))
320 return cond(var, &val, op, noeval);
322 result = assignment(yylex(), noeval);
327 result = do_binop(op - 11, arith_lookupvarint(val.name), result);
328 snprintf(sresult, sizeof(sresult), ARITH_FORMAT_STR, result);
329 setvar(val.name, sresult, 0);
336 struct stackmark smark;
339 setstackmark(&smark);
341 arith_buf = arith_startbuf = s;
343 result = assignment(yylex(), 0);
346 yyerror("expecting EOF");
348 popstackmark(&smark);
354 * The exp(1) builtin.
357 expcmd(int argc, char **argv)
368 * Concatenate arguments.
370 STARTSTACKSTR(concat);
374 STPUTC(*p++, concat);
375 if ((p = *ap++) == NULL)
379 STPUTC('\0', concat);
380 p = grabstackstr(concat);
387 out1fmt(ARITH_FORMAT_STR "\n", i);