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: head/bin/sh/arith_yacc.c 230530 2012-01-25 08:42:19Z charnier $
43 #include "arith_yacc.h"
53 #if ARITH_BOR + 11 != ARITH_BORASS || ARITH_ASS + 11 != ARITH_EQ
54 #error Arithmetic tokens are out of order.
57 static const char *arith_startbuf;
59 const char *arith_buf;
62 static int last_token;
64 #define ARITH_PRECEDENCE(op, prec) [op - ARITH_BINOP_MIN] = prec
66 static const char prec[ARITH_BINOP_MAX - ARITH_BINOP_MIN] = {
67 ARITH_PRECEDENCE(ARITH_MUL, 0),
68 ARITH_PRECEDENCE(ARITH_DIV, 0),
69 ARITH_PRECEDENCE(ARITH_REM, 0),
70 ARITH_PRECEDENCE(ARITH_ADD, 1),
71 ARITH_PRECEDENCE(ARITH_SUB, 1),
72 ARITH_PRECEDENCE(ARITH_LSHIFT, 2),
73 ARITH_PRECEDENCE(ARITH_RSHIFT, 2),
74 ARITH_PRECEDENCE(ARITH_LT, 3),
75 ARITH_PRECEDENCE(ARITH_LE, 3),
76 ARITH_PRECEDENCE(ARITH_GT, 3),
77 ARITH_PRECEDENCE(ARITH_GE, 3),
78 ARITH_PRECEDENCE(ARITH_EQ, 4),
79 ARITH_PRECEDENCE(ARITH_NE, 4),
80 ARITH_PRECEDENCE(ARITH_BAND, 5),
81 ARITH_PRECEDENCE(ARITH_BXOR, 6),
82 ARITH_PRECEDENCE(ARITH_BOR, 7),
85 #define ARITH_MAX_PREC 8
88 yyerror(const char *s)
90 error("arithmetic expression: %s: \"%s\"", s, arith_startbuf);
95 arith_lookupvarint(char *varname)
101 str = lookupvar(varname);
102 if (uflag && str == NULL)
103 yyerror("variable not set");
104 if (str == NULL || *str == '\0')
107 result = strtoarith_t(str, &p, 0);
108 if (errno != 0 || *p != '\0')
109 yyerror("variable conversion error");
116 return prec[op - ARITH_BINOP_MIN];
120 higher_prec(int op1, int op2)
122 return arith_prec(op1) < arith_prec(op2);
126 do_binop(int op, arith_t a, arith_t b)
134 yyerror("division by zero");
135 if (a == ARITH_MIN && b == -1)
136 yyerror("divide error");
137 return op == ARITH_REM ? a % b : a / b;
139 return (uintmax_t)a * (uintmax_t)b;
141 return (uintmax_t)a + (uintmax_t)b;
143 return (uintmax_t)a - (uintmax_t)b;
169 static arith_t assignment(int var, int noeval);
172 primary(int token, union yystype *val, int op, int noeval)
179 result = assignment(op, noeval);
180 if (last_token != ARITH_RPAREN)
181 yyerror("expecting ')'");
182 last_token = yylex();
189 return noeval ? val->val : arith_lookupvarint(val->name);
197 return -primary(op, val, yylex(), noeval);
200 return !primary(op, val, yylex(), noeval);
203 return ~primary(op, val, yylex(), noeval);
205 yyerror("expecting primary");
210 binop2(arith_t a, int op, int precedence, int noeval)
221 b = primary(token, &val, yylex(), noeval);
224 if (op2 >= ARITH_BINOP_MIN && op2 < ARITH_BINOP_MAX &&
225 higher_prec(op2, op)) {
226 b = binop2(b, op2, arith_prec(op), noeval);
230 a = noeval ? b : do_binop(op, a, b);
232 if (op2 < ARITH_BINOP_MIN || op2 >= ARITH_BINOP_MAX ||
233 arith_prec(op2) >= precedence)
241 binop(int token, union yystype *val, int op, int noeval)
243 arith_t a = primary(token, val, op, noeval);
246 if (op < ARITH_BINOP_MIN || op >= ARITH_BINOP_MAX)
249 return binop2(a, op, ARITH_MAX_PREC, noeval);
253 and(int token, union yystype *val, int op, int noeval)
255 arith_t a = binop(token, val, op, noeval);
265 b = and(token, val, yylex(), noeval | !a);
271 or(int token, union yystype *val, int op, int noeval)
273 arith_t a = and(token, val, op, noeval);
283 b = or(token, val, yylex(), noeval | !!a);
289 cond(int token, union yystype *val, int op, int noeval)
291 arith_t a = or(token, val, op, noeval);
295 if (last_token != ARITH_QMARK)
298 b = assignment(yylex(), noeval | !a);
300 if (last_token != ARITH_COLON)
301 yyerror("expecting ':'");
306 c = cond(token, val, yylex(), noeval | !!a);
312 assignment(int var, int noeval)
314 union yystype val = yylval;
317 char sresult[DIGITS(result) + 1];
319 if (var != ARITH_VAR)
320 return cond(var, &val, op, noeval);
322 if (op != ARITH_ASS && (op < ARITH_ASS_MIN || op >= ARITH_ASS_MAX))
323 return cond(var, &val, op, noeval);
325 result = assignment(yylex(), noeval);
330 result = do_binop(op - 11, arith_lookupvarint(val.name), result);
331 snprintf(sresult, sizeof(sresult), ARITH_FORMAT_STR, result);
332 setvar(val.name, sresult, 0);
339 struct stackmark smark;
342 setstackmark(&smark);
344 arith_buf = arith_startbuf = s;
346 result = assignment(yylex(), 0);
349 yyerror("expecting EOF");
351 popstackmark(&smark);
357 * The exp(1) builtin.
360 letcmd(int argc, char **argv)
371 * Concatenate arguments.
373 STARTSTACKSTR(concat);
377 STPUTC(*p++, concat);
378 if ((p = *ap++) == NULL)
382 STPUTC('\0', concat);
383 p = grabstackstr(concat);
390 out1fmt(ARITH_FORMAT_STR "\n", i);