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-rw-r--r--bin/expr/expr.y555
1 files changed, 555 insertions, 0 deletions
diff --git a/bin/expr/expr.y b/bin/expr/expr.y
new file mode 100644
index 000000000000..1856ec84d0f7
--- /dev/null
+++ b/bin/expr/expr.y
@@ -0,0 +1,555 @@
+%{
+/*-
+ * Written by Pace Willisson (pace@blitz.com)
+ * and placed in the public domain.
+ *
+ * Largely rewritten by J.T. Conklin (jtc@wimsey.com)
+ *
+ * $FreeBSD$
+ */
+
+#include <sys/types.h>
+
+#include <ctype.h>
+#include <err.h>
+#include <errno.h>
+#include <inttypes.h>
+#include <limits.h>
+#include <locale.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <regex.h>
+#include <unistd.h>
+
+/*
+ * POSIX specifies a specific error code for syntax errors. We exit
+ * with this code for all errors.
+ */
+#define ERR_EXIT 2
+
+enum valtype {
+ integer, numeric_string, string
+} ;
+
+struct val {
+ enum valtype type;
+ union {
+ char *s;
+ intmax_t i;
+ } u;
+} ;
+
+char **av;
+int nonposix;
+struct val *result;
+
+void assert_to_integer(struct val *);
+void assert_div(intmax_t, intmax_t);
+void assert_minus(intmax_t, intmax_t, intmax_t);
+void assert_plus(intmax_t, intmax_t, intmax_t);
+void assert_times(intmax_t, intmax_t, intmax_t);
+int compare_vals(struct val *, struct val *);
+void free_value(struct val *);
+int is_integer(const char *);
+int is_string(struct val *);
+int is_zero_or_null(struct val *);
+struct val *make_integer(intmax_t);
+struct val *make_str(const char *);
+struct val *op_and(struct val *, struct val *);
+struct val *op_colon(struct val *, struct val *);
+struct val *op_div(struct val *, struct val *);
+struct val *op_eq(struct val *, struct val *);
+struct val *op_ge(struct val *, struct val *);
+struct val *op_gt(struct val *, struct val *);
+struct val *op_le(struct val *, struct val *);
+struct val *op_lt(struct val *, struct val *);
+struct val *op_minus(struct val *, struct val *);
+struct val *op_ne(struct val *, struct val *);
+struct val *op_or(struct val *, struct val *);
+struct val *op_plus(struct val *, struct val *);
+struct val *op_rem(struct val *, struct val *);
+struct val *op_times(struct val *, struct val *);
+int to_integer(struct val *);
+void to_string(struct val *);
+int yyerror(const char *);
+int yylex(void);
+
+%}
+
+%union
+{
+ struct val *val;
+}
+
+%left <val> '|'
+%left <val> '&'
+%left <val> '=' '>' '<' GE LE NE
+%left <val> '+' '-'
+%left <val> '*' '/' '%'
+%left <val> ':'
+
+%token <val> TOKEN
+%type <val> start expr
+
+%%
+
+start: expr { result = $$; }
+
+expr: TOKEN
+ | '(' expr ')' { $$ = $2; }
+ | expr '|' expr { $$ = op_or($1, $3); }
+ | expr '&' expr { $$ = op_and($1, $3); }
+ | expr '=' expr { $$ = op_eq($1, $3); }
+ | expr '>' expr { $$ = op_gt($1, $3); }
+ | expr '<' expr { $$ = op_lt($1, $3); }
+ | expr GE expr { $$ = op_ge($1, $3); }
+ | expr LE expr { $$ = op_le($1, $3); }
+ | expr NE expr { $$ = op_ne($1, $3); }
+ | expr '+' expr { $$ = op_plus($1, $3); }
+ | expr '-' expr { $$ = op_minus($1, $3); }
+ | expr '*' expr { $$ = op_times($1, $3); }
+ | expr '/' expr { $$ = op_div($1, $3); }
+ | expr '%' expr { $$ = op_rem($1, $3); }
+ | expr ':' expr { $$ = op_colon($1, $3); }
+ ;
+
+%%
+
+struct val *
+make_integer(intmax_t i)
+{
+ struct val *vp;
+
+ vp = (struct val *)malloc(sizeof(*vp));
+ if (vp == NULL)
+ errx(ERR_EXIT, "malloc() failed");
+
+ vp->type = integer;
+ vp->u.i = i;
+ return (vp);
+}
+
+struct val *
+make_str(const char *s)
+{
+ struct val *vp;
+
+ vp = (struct val *)malloc(sizeof(*vp));
+ if (vp == NULL || ((vp->u.s = strdup(s)) == NULL))
+ errx(ERR_EXIT, "malloc() failed");
+
+ if (is_integer(s))
+ vp->type = numeric_string;
+ else
+ vp->type = string;
+
+ return (vp);
+}
+
+void
+free_value(struct val *vp)
+{
+ if (vp->type == string || vp->type == numeric_string)
+ free(vp->u.s);
+}
+
+int
+to_integer(struct val *vp)
+{
+ intmax_t i;
+
+ /* we can only convert numeric_string to integer, here */
+ if (vp->type == numeric_string) {
+ errno = 0;
+ i = strtoimax(vp->u.s, (char **)NULL, 10);
+ /* just keep as numeric_string, if the conversion fails */
+ if (errno != ERANGE) {
+ free(vp->u.s);
+ vp->u.i = i;
+ vp->type = integer;
+ }
+ }
+ return (vp->type == integer);
+}
+
+void
+assert_to_integer(struct val *vp)
+{
+ if (vp->type == string)
+ errx(ERR_EXIT, "not a decimal number: '%s'", vp->u.s);
+ if (!to_integer(vp))
+ errx(ERR_EXIT, "operand too large: '%s'", vp->u.s);
+}
+
+void
+to_string(struct val *vp)
+{
+ char *tmp;
+
+ if (vp->type == string || vp->type == numeric_string)
+ return;
+
+ /*
+ * log_10(x) ~= 0.3 * log_2(x). Rounding up gives the number
+ * of digits; add one each for the sign and terminating null
+ * character, respectively.
+ */
+#define NDIGITS(x) (3 * (sizeof(x) * CHAR_BIT) / 10 + 1 + 1 + 1)
+ tmp = malloc(NDIGITS(vp->u.i));
+ if (tmp == NULL)
+ errx(ERR_EXIT, "malloc() failed");
+
+ sprintf(tmp, "%jd", vp->u.i);
+ vp->type = string;
+ vp->u.s = tmp;
+}
+
+int
+is_integer(const char *s)
+{
+ if (nonposix) {
+ if (*s == '\0')
+ return (1);
+ while (isspace((unsigned char)*s))
+ s++;
+ }
+ if (*s == '-' || (nonposix && *s == '+'))
+ s++;
+ if (*s == '\0')
+ return (0);
+ while (isdigit((unsigned char)*s))
+ s++;
+ return (*s == '\0');
+}
+
+int
+is_string(struct val *vp)
+{
+ /* only TRUE if this string is not a valid integer */
+ return (vp->type == string);
+}
+
+int
+yylex(void)
+{
+ char *p;
+
+ if (*av == NULL)
+ return (0);
+
+ p = *av++;
+
+ if (strlen(p) == 1) {
+ if (strchr("|&=<>+-*/%:()", *p))
+ return (*p);
+ } else if (strlen(p) == 2 && p[1] == '=') {
+ switch (*p) {
+ case '>': return (GE);
+ case '<': return (LE);
+ case '!': return (NE);
+ }
+ }
+
+ yylval.val = make_str(p);
+ return (TOKEN);
+}
+
+int
+is_zero_or_null(struct val *vp)
+{
+ if (vp->type == integer)
+ return (vp->u.i == 0);
+
+ return (*vp->u.s == 0 || (to_integer(vp) && vp->u.i == 0));
+}
+
+int
+main(int argc, char *argv[])
+{
+ int c;
+
+ setlocale(LC_ALL, "");
+ if (getenv("EXPR_COMPAT") != NULL
+ || check_utility_compat("expr")) {
+ av = argv + 1;
+ nonposix = 1;
+ } else {
+ while ((c = getopt(argc, argv, "e")) != -1) {
+ switch (c) {
+ case 'e':
+ nonposix = 1;
+ break;
+ default:
+ errx(ERR_EXIT,
+ "usage: expr [-e] expression\n");
+ }
+ }
+ av = argv + optind;
+ }
+
+ yyparse();
+
+ if (result->type == integer)
+ printf("%jd\n", result->u.i);
+ else
+ printf("%s\n", result->u.s);
+
+ return (is_zero_or_null(result));
+}
+
+int
+yyerror(const char *s __unused)
+{
+ errx(ERR_EXIT, "syntax error");
+}
+
+struct val *
+op_or(struct val *a, struct val *b)
+{
+ if (!is_zero_or_null(a)) {
+ free_value(b);
+ return (a);
+ }
+ free_value(a);
+ if (!is_zero_or_null(b))
+ return (b);
+ free_value(b);
+ return (make_integer((intmax_t)0));
+}
+
+struct val *
+op_and(struct val *a, struct val *b)
+{
+ if (is_zero_or_null(a) || is_zero_or_null(b)) {
+ free_value(a);
+ free_value(b);
+ return (make_integer((intmax_t)0));
+ } else {
+ free_value(b);
+ return (a);
+ }
+}
+
+int
+compare_vals(struct val *a, struct val *b)
+{
+ int r;
+
+ if (is_string(a) || is_string(b)) {
+ to_string(a);
+ to_string(b);
+ r = strcoll(a->u.s, b->u.s);
+ } else {
+ assert_to_integer(a);
+ assert_to_integer(b);
+ if (a->u.i > b->u.i)
+ r = 1;
+ else if (a->u.i < b->u.i)
+ r = -1;
+ else
+ r = 0;
+ }
+
+ free_value(a);
+ free_value(b);
+ return (r);
+}
+
+struct val *
+op_eq(struct val *a, struct val *b)
+{
+ return (make_integer((intmax_t)(compare_vals(a, b) == 0)));
+}
+
+struct val *
+op_gt(struct val *a, struct val *b)
+{
+ return (make_integer((intmax_t)(compare_vals(a, b) > 0)));
+}
+
+struct val *
+op_lt(struct val *a, struct val *b)
+{
+ return (make_integer((intmax_t)(compare_vals(a, b) < 0)));
+}
+
+struct val *
+op_ge(struct val *a, struct val *b)
+{
+ return (make_integer((intmax_t)(compare_vals(a, b) >= 0)));
+}
+
+struct val *
+op_le(struct val *a, struct val *b)
+{
+ return (make_integer((intmax_t)(compare_vals(a, b) <= 0)));
+}
+
+struct val *
+op_ne(struct val *a, struct val *b)
+{
+ return (make_integer((intmax_t)(compare_vals(a, b) != 0)));
+}
+
+void
+assert_plus(intmax_t a, intmax_t b, intmax_t r)
+{
+ /*
+ * sum of two positive numbers must be positive,
+ * sum of two negative numbers must be negative
+ */
+ if ((a > 0 && b > 0 && r <= 0) ||
+ (a < 0 && b < 0 && r >= 0))
+ errx(ERR_EXIT, "overflow");
+}
+
+struct val *
+op_plus(struct val *a, struct val *b)
+{
+ struct val *r;
+
+ assert_to_integer(a);
+ assert_to_integer(b);
+ r = make_integer(a->u.i + b->u.i);
+ assert_plus(a->u.i, b->u.i, r->u.i);
+
+ free_value(a);
+ free_value(b);
+ return (r);
+}
+
+void
+assert_minus(intmax_t a, intmax_t b, intmax_t r)
+{
+ /* special case subtraction of INTMAX_MIN */
+ if (b == INTMAX_MIN && a < 0)
+ errx(ERR_EXIT, "overflow");
+ /* check addition of negative subtrahend */
+ assert_plus(a, -b, r);
+}
+
+struct val *
+op_minus(struct val *a, struct val *b)
+{
+ struct val *r;
+
+ assert_to_integer(a);
+ assert_to_integer(b);
+ r = make_integer(a->u.i - b->u.i);
+ assert_minus(a->u.i, b->u.i, r->u.i);
+
+ free_value(a);
+ free_value(b);
+ return (r);
+}
+
+void
+assert_times(intmax_t a, intmax_t b, intmax_t r)
+{
+ /*
+ * if first operand is 0, no overflow is possible,
+ * else result of division test must match second operand
+ */
+ if (a != 0 && r / a != b)
+ errx(ERR_EXIT, "overflow");
+}
+
+struct val *
+op_times(struct val *a, struct val *b)
+{
+ struct val *r;
+
+ assert_to_integer(a);
+ assert_to_integer(b);
+ r = make_integer(a->u.i * b->u.i);
+ assert_times(a->u.i, b->u.i, r->u.i);
+
+ free_value(a);
+ free_value(b);
+ return (r);
+}
+
+void
+assert_div(intmax_t a, intmax_t b)
+{
+ if (b == 0)
+ errx(ERR_EXIT, "division by zero");
+ /* only INTMAX_MIN / -1 causes overflow */
+ if (a == INTMAX_MIN && b == -1)
+ errx(ERR_EXIT, "overflow");
+}
+
+struct val *
+op_div(struct val *a, struct val *b)
+{
+ struct val *r;
+
+ assert_to_integer(a);
+ assert_to_integer(b);
+ /* assert based on operands only, not on result */
+ assert_div(a->u.i, b->u.i);
+ r = make_integer(a->u.i / b->u.i);
+
+ free_value(a);
+ free_value(b);
+ return (r);
+}
+
+struct val *
+op_rem(struct val *a, struct val *b)
+{
+ struct val *r;
+
+ assert_to_integer(a);
+ assert_to_integer(b);
+ /* pass a=1 to only check for div by zero */
+ assert_div(1, b->u.i);
+ r = make_integer(a->u.i % b->u.i);
+
+ free_value(a);
+ free_value(b);
+ return (r);
+}
+
+struct val *
+op_colon(struct val *a, struct val *b)
+{
+ regex_t rp;
+ regmatch_t rm[2];
+ char errbuf[256];
+ int eval;
+ struct val *v;
+
+ /* coerce both arguments to strings */
+ to_string(a);
+ to_string(b);
+
+ /* compile regular expression */
+ if ((eval = regcomp(&rp, b->u.s, 0)) != 0) {
+ regerror(eval, &rp, errbuf, sizeof(errbuf));
+ errx(ERR_EXIT, "%s", errbuf);
+ }
+
+ /* compare string against pattern */
+ /* remember that patterns are anchored to the beginning of the line */
+ if (regexec(&rp, a->u.s, (size_t)2, rm, 0) == 0 && rm[0].rm_so == 0)
+ if (rm[1].rm_so >= 0) {
+ *(a->u.s + rm[1].rm_eo) = '\0';
+ v = make_str(a->u.s + rm[1].rm_so);
+
+ } else
+ v = make_integer((intmax_t)(rm[0].rm_eo));
+ else
+ if (rp.re_nsub == 0)
+ v = make_integer((intmax_t)0);
+ else
+ v = make_str("");
+
+ /* free arguments and pattern buffer */
+ free_value(a);
+ free_value(b);
+ regfree(&rp);
+
+ return (v);
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-26 16:19:41 +0000