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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22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD$");
44 #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
87 static __dead2 void yyerror(const char *s)
89 error("arithmetic expression: %s: \"%s\"", s, arith_startbuf);
93 static arith_t arith_lookupvarint(char *varname)
99 str = lookupvar(varname);
100 if (uflag && str == NULL)
101 yyerror("variable not set");
102 if (str == NULL || *str == '\0')
105 result = strtoarith_t(str, &p, 0);
106 if (errno != 0 || *p != '\0')
107 yyerror("variable conversion error");
111 static inline int arith_prec(int op)
113 return prec[op - ARITH_BINOP_MIN];
116 static inline int higher_prec(int op1, int op2)
118 return arith_prec(op1) < arith_prec(op2);
121 static arith_t do_binop(int op, arith_t a, arith_t b)
129 yyerror("division by zero");
130 if (a == ARITH_MIN && b == -1)
131 yyerror("divide error");
132 return op == ARITH_REM ? a % b : a / b;
164 static arith_t assignment(int var, int noeval);
166 static arith_t primary(int token, union yystype *val, int op, int noeval)
173 result = assignment(op, noeval);
174 if (last_token != ARITH_RPAREN)
175 yyerror("expecting ')'");
176 last_token = yylex();
183 return noeval ? val->val : arith_lookupvarint(val->name);
191 return -primary(op, val, yylex(), noeval);
194 return !primary(op, val, yylex(), noeval);
197 return ~primary(op, val, yylex(), noeval);
199 yyerror("expecting primary");
203 static arith_t binop2(arith_t a, int op, int precedence, int noeval)
214 b = primary(token, &val, yylex(), noeval);
217 if (op2 >= ARITH_BINOP_MIN && op2 < ARITH_BINOP_MAX &&
218 higher_prec(op2, op)) {
219 b = binop2(b, op2, arith_prec(op), noeval);
223 a = noeval ? b : do_binop(op, a, b);
225 if (op2 < ARITH_BINOP_MIN || op2 >= ARITH_BINOP_MAX ||
226 arith_prec(op2) >= precedence)
233 static arith_t binop(int token, union yystype *val, int op, int noeval)
235 arith_t a = primary(token, val, op, noeval);
238 if (op < ARITH_BINOP_MIN || op >= ARITH_BINOP_MAX)
241 return binop2(a, op, ARITH_MAX_PREC, noeval);
244 static arith_t and(int token, union yystype *val, int op, int noeval)
246 arith_t a = binop(token, val, op, noeval);
256 b = and(token, val, yylex(), noeval | !a);
261 static arith_t or(int token, union yystype *val, int op, int noeval)
263 arith_t a = and(token, val, op, noeval);
273 b = or(token, val, yylex(), noeval | !!a);
278 static arith_t cond(int token, union yystype *val, int op, int noeval)
280 arith_t a = or(token, val, op, noeval);
284 if (last_token != ARITH_QMARK)
287 b = assignment(yylex(), noeval | !a);
289 if (last_token != ARITH_COLON)
290 yyerror("expecting ':'");
295 c = cond(token, val, yylex(), noeval | !!a);
300 static arith_t assignment(int var, int noeval)
302 union yystype val = yylval;
305 char sresult[DIGITS(result) + 1];
307 if (var != ARITH_VAR)
308 return cond(var, &val, op, noeval);
310 if (op != ARITH_ASS && (op < ARITH_ASS_MIN || op >= ARITH_ASS_MAX))
311 return cond(var, &val, op, noeval);
313 result = assignment(yylex(), noeval);
318 result = do_binop(op - 11, arith_lookupvarint(val.name), result);
319 snprintf(sresult, sizeof(sresult), ARITH_FORMAT_STR, result);
320 setvar(val.name, sresult, 0);
324 arith_t arith(const char *s)
326 struct stackmark smark;
329 setstackmark(&smark);
331 arith_buf = arith_startbuf = s;
333 result = assignment(yylex(), 0);
336 yyerror("expecting EOF");
338 popstackmark(&smark);
344 * The exp(1) builtin.
347 letcmd(int argc, char **argv)
358 * Concatenate arguments.
360 STARTSTACKSTR(concat);
364 STPUTC(*p++, concat);
365 if ((p = *ap++) == NULL)
369 STPUTC('\0', concat);
370 p = grabstackstr(concat);
377 out1fmt(ARITH_FORMAT_STR "\n", i);