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Diffstat (limited to '')
| -rw-r--r-- | bin/1sh/arith_yacc.c | 381 |
1 files changed, 381 insertions, 0 deletions
diff --git a/bin/1sh/arith_yacc.c b/bin/1sh/arith_yacc.c new file mode 100644 index 00000000..57285831 --- /dev/null +++ b/bin/1sh/arith_yacc.c @@ -0,0 +1,381 @@ +/*- + * Copyright (c) 1993 + * The Regents of the University of California. All rights reserved. + * Copyright (c) 2007 + * Herbert Xu <herbert@gondor.apana.org.au>. All rights reserved. + * + * This code is derived from software contributed to Berkeley by + * Kenneth Almquist. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include <sys/cdefs.h> +/* $FreeBSD: releng/12.1/bin/sh/arith_yacc.c 345117 2019-03-13 21:53:10Z jilles $ */ + +#include <limits.h> +#include <errno.h> +#include <inttypes.h> +#include <stdlib.h> +#include <stdio.h> +#include "arith.h" +#include "arith_yacc.h" +#include "expand.h" +#include "shell.h" +#include "error.h" +#include "memalloc.h" +#include "output.h" +#include "options.h" +#include "var.h" + +#if ARITH_BOR + 11 != ARITH_BORASS || ARITH_ASS + 11 != ARITH_EQ +#error Arithmetic tokens are out of order. +#endif + +static const char *arith_startbuf; + +const char *arith_buf; +union yystype yylval; + +static int last_token; + +#define ARITH_PRECEDENCE(op, prec) [op - ARITH_BINOP_MIN] = prec + +static const char prec[ARITH_BINOP_MAX - ARITH_BINOP_MIN] = { + ARITH_PRECEDENCE(ARITH_MUL, 0), + ARITH_PRECEDENCE(ARITH_DIV, 0), + ARITH_PRECEDENCE(ARITH_REM, 0), + ARITH_PRECEDENCE(ARITH_ADD, 1), + ARITH_PRECEDENCE(ARITH_SUB, 1), + ARITH_PRECEDENCE(ARITH_LSHIFT, 2), + ARITH_PRECEDENCE(ARITH_RSHIFT, 2), + ARITH_PRECEDENCE(ARITH_LT, 3), + ARITH_PRECEDENCE(ARITH_LE, 3), + ARITH_PRECEDENCE(ARITH_GT, 3), + ARITH_PRECEDENCE(ARITH_GE, 3), + ARITH_PRECEDENCE(ARITH_EQ, 4), + ARITH_PRECEDENCE(ARITH_NE, 4), + ARITH_PRECEDENCE(ARITH_BAND, 5), + ARITH_PRECEDENCE(ARITH_BXOR, 6), + ARITH_PRECEDENCE(ARITH_BOR, 7), +}; + +#define ARITH_MAX_PREC 8 + +int letcmd(int, char **); + +static __attribute__((noreturn)) void yyerror(const char *s) +{ + error("arithmetic expression: %s: \"%s\"", s, arith_startbuf); + /* NOTREACHED */ +} + +static arith_t arith_lookupvarint(char *varname) +{ + const char *str; + char *p; + arith_t result; + + str = lookupvar(varname); + if (uflag && str == NULL) + yyerror("variable not set"); + if (str == NULL || *str == '\0') + str = "0"; + errno = 0; + result = strtoarith_t(str, &p); + if (errno != 0 || *p != '\0') + yyerror("variable conversion error"); + return result; +} + +static inline int arith_prec(int op) +{ + return prec[op - ARITH_BINOP_MIN]; +} + +static inline int higher_prec(int op1, int op2) +{ + return arith_prec(op1) < arith_prec(op2); +} + +static arith_t do_binop(int op, arith_t a, arith_t b) +{ + + switch (op) { + default: + case ARITH_REM: + case ARITH_DIV: + if (!b) + yyerror("division by zero"); + if (a == ARITH_MIN && b == -1) + yyerror("divide error"); + return op == ARITH_REM ? a % b : a / b; + case ARITH_MUL: + return (uintmax_t)a * (uintmax_t)b; + case ARITH_ADD: + return (uintmax_t)a + (uintmax_t)b; + case ARITH_SUB: + return (uintmax_t)a - (uintmax_t)b; + case ARITH_LSHIFT: + return (uintmax_t)a << (b & (sizeof(uintmax_t) * CHAR_BIT - 1)); + case ARITH_RSHIFT: + return a >> (b & (sizeof(uintmax_t) * CHAR_BIT - 1)); + case ARITH_LT: + return a < b; + case ARITH_LE: + return a <= b; + case ARITH_GT: + return a > b; + case ARITH_GE: + return a >= b; + case ARITH_EQ: + return a == b; + case ARITH_NE: + return a != b; + case ARITH_BAND: + return a & b; + case ARITH_BXOR: + return a ^ b; + case ARITH_BOR: + return a | b; + } +} + +static arith_t assignment(int var, int noeval); + +static arith_t primary(int token, union yystype *val, int op, int noeval) +{ + arith_t result; + +again: + switch (token) { + case ARITH_LPAREN: + result = assignment(op, noeval); + if (last_token != ARITH_RPAREN) + yyerror("expecting ')'"); + last_token = yylex(); + return result; + case ARITH_NUM: + last_token = op; + return val->val; + case ARITH_VAR: + last_token = op; + return noeval ? val->val : arith_lookupvarint(val->name); + case ARITH_ADD: + token = op; + *val = yylval; + op = yylex(); + goto again; + case ARITH_SUB: + *val = yylval; + return -primary(op, val, yylex(), noeval); + case ARITH_NOT: + *val = yylval; + return !primary(op, val, yylex(), noeval); + case ARITH_BNOT: + *val = yylval; + return ~primary(op, val, yylex(), noeval); + default: + yyerror("expecting primary"); + } +} + +static arith_t binop2(arith_t a, int op, int precedence, int noeval) +{ + for (;;) { + union yystype val; + arith_t b; + int op2; + int token; + + token = yylex(); + val = yylval; + + b = primary(token, &val, yylex(), noeval); + + op2 = last_token; + if (op2 >= ARITH_BINOP_MIN && op2 < ARITH_BINOP_MAX && + higher_prec(op2, op)) { + b = binop2(b, op2, arith_prec(op), noeval); + op2 = last_token; + } + + a = noeval ? b : do_binop(op, a, b); + + if (op2 < ARITH_BINOP_MIN || op2 >= ARITH_BINOP_MAX || + arith_prec(op2) >= precedence) + return a; + + op = op2; + } +} + +static arith_t binop(int token, union yystype *val, int op, int noeval) +{ + arith_t a = primary(token, val, op, noeval); + + op = last_token; + if (op < ARITH_BINOP_MIN || op >= ARITH_BINOP_MAX) + return a; + + return binop2(a, op, ARITH_MAX_PREC, noeval); +} + +static arith_t and(int token, union yystype *val, int op, int noeval) +{ + arith_t a = binop(token, val, op, noeval); + arith_t b; + + op = last_token; + if (op != ARITH_AND) + return a; + + token = yylex(); + *val = yylval; + + b = and(token, val, yylex(), noeval | !a); + + return a && b; +} + +static arith_t or(int token, union yystype *val, int op, int noeval) +{ + arith_t a = and(token, val, op, noeval); + arith_t b; + + op = last_token; + if (op != ARITH_OR) + return a; + + token = yylex(); + *val = yylval; + + b = or(token, val, yylex(), noeval | !!a); + + return a || b; +} + +static arith_t cond(int token, union yystype *val, int op, int noeval) +{ + arith_t a = or(token, val, op, noeval); + arith_t b; + arith_t c; + + if (last_token != ARITH_QMARK) + return a; + + b = assignment(yylex(), noeval | !a); + + if (last_token != ARITH_COLON) + yyerror("expecting ':'"); + + token = yylex(); + *val = yylval; + + c = cond(token, val, yylex(), noeval | !!a); + + return a ? b : c; +} + +static arith_t assignment(int var, int noeval) +{ + union yystype val = yylval; + int op = yylex(); + arith_t result; + char sresult[DIGITS(result) + 1]; + + if (var != ARITH_VAR) + return cond(var, &val, op, noeval); + + if (op != ARITH_ASS && (op < ARITH_ASS_MIN || op >= ARITH_ASS_MAX)) + return cond(var, &val, op, noeval); + + result = assignment(yylex(), noeval); + if (noeval) + return result; + + if (op != ARITH_ASS) + result = do_binop(op - 11, arith_lookupvarint(val.name), result); + snprintf(sresult, sizeof(sresult), ARITH_FORMAT_STR, result); + setvar(val.name, sresult, 0); + return result; +} + +arith_t arith(const char *s) +{ + struct stackmark smark; + arith_t result; + + setstackmark(&smark); + + arith_buf = arith_startbuf = s; + + result = assignment(yylex(), 0); + + if (last_token) + yyerror("expecting EOF"); + + popstackmark(&smark); + + return result; +} + +/* + * The exp(1) builtin. + */ +int +letcmd(int argc, char **argv) +{ + const char *p; + char *concat; + char **ap; + arith_t i; + + if (argc > 1) { + p = argv[1]; + if (argc > 2) { + /* + * Concatenate arguments. + */ + STARTSTACKSTR(concat); + ap = argv + 2; + for (;;) { + while (*p) + STPUTC(*p++, concat); + if ((p = *ap++) == NULL) + break; + STPUTC(' ', concat); + } + STPUTC('\0', concat); + p = grabstackstr(concat); + } + } else + p = ""; + + i = arith(p); + + out1fmt(ARITH_FORMAT_STR "\n", i); + return !i; +} |