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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 1.1 2011/02/08 23:18:06 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 return op == ARITH_REM ? a % b : a / b;
164 static arith_t assignment(int var, int noeval);
167 primary(int token, union yystype *val, int op, int noeval)
174 result = assignment(op, noeval);
175 if (last_token != ARITH_RPAREN)
176 yyerror("expecting ')'");
177 last_token = yylex();
184 return noeval ? val->val : arith_lookupvarint(val->name);
192 return -primary(op, val, yylex(), noeval);
195 return !primary(op, val, yylex(), noeval);
198 return ~primary(op, val, yylex(), noeval);
200 yyerror("expecting primary");
205 binop2(arith_t a, int op, int lprec, int noeval)
216 b = primary(token, &val, yylex(), noeval);
219 if (op2 >= ARITH_BINOP_MIN && op2 < ARITH_BINOP_MAX &&
220 higher_prec(op2, op)) {
221 b = binop2(b, op2, arith_prec(op), noeval);
225 a = noeval ? b : do_binop(op, a, b);
227 if (op2 < ARITH_BINOP_MIN || op2 >= ARITH_BINOP_MAX ||
228 arith_prec(op2) >= lprec)
236 binop(int token, union yystype *val, int op, int noeval)
238 arith_t a = primary(token, val, op, noeval);
241 if (op < ARITH_BINOP_MIN || op >= ARITH_BINOP_MAX)
244 return binop2(a, op, ARITH_MAX_PREC, noeval);
248 and(int token, union yystype *val, int op, int noeval)
250 arith_t a = binop(token, val, op, noeval);
260 b = and(token, val, yylex(), noeval | !a);
266 or(int token, union yystype *val, int op, int noeval)
268 arith_t a = and(token, val, op, noeval);
278 b = or(token, val, yylex(), noeval | !!a);
284 cond(int token, union yystype *val, int op, int noeval)
286 arith_t a = or(token, val, op, noeval);
290 if (last_token != ARITH_QMARK)
293 b = assignment(yylex(), noeval | !a);
295 if (last_token != ARITH_COLON)
296 yyerror("expecting ':'");
301 c = cond(token, val, yylex(), noeval | !!a);
307 assignment(int var, int noeval)
309 union yystype val = yylval;
312 char sresult[DIGITS(result) + 1];
314 if (var != ARITH_VAR)
315 return cond(var, &val, op, noeval);
317 if (op != ARITH_ASS && (op < ARITH_ASS_MIN || op >= ARITH_ASS_MAX))
318 return cond(var, &val, op, noeval);
320 result = assignment(yylex(), noeval);
325 result = do_binop(op - 11, arith_lookupvarint(val.name), result);
326 snprintf(sresult, sizeof(sresult), ARITH_FORMAT_STR, result);
327 setvar(val.name, sresult, 0);
334 struct stackmark smark;
337 setstackmark(&smark);
339 arith_buf = arith_startbuf = s;
341 result = assignment(yylex(), 0);
344 yyerror("expecting EOF");
346 popstackmark(&smark);
352 * The exp(1) builtin.
355 expcmd(int argc, char **argv)
366 * Concatenate arguments.
368 STARTSTACKSTR(concat);
372 STPUTC(*p++, concat);
373 if ((p = *ap++) == NULL)
377 STPUTC('\0', concat);
378 p = grabstackstr(concat);
385 out1fmt(ARITH_FORMAT_STR "\n", i);