Import regex from OpenBSD
Change-Id: I7ad7d907ef65e4e345f94777d730813b1270a612
diff --git a/libc/regex/regerror.c b/libc/regex/regerror.c
new file mode 100644
index 0000000..894a939
--- /dev/null
+++ b/libc/regex/regerror.c
@@ -0,0 +1,130 @@
+/* $OpenBSD: regerror.c,v 1.13 2005/08/05 13:03:00 espie Exp $ */
+/*-
+ * Copyright (c) 1992, 1993, 1994 Henry Spencer.
+ * Copyright (c) 1992, 1993, 1994
+ * The Regents of the University of California. All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Henry Spencer.
+ *
+ * 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.
+ *
+ * @(#)regerror.c 8.4 (Berkeley) 3/20/94
+ */
+
+#include <sys/types.h>
+#include <stdio.h>
+#include <string.h>
+#include <ctype.h>
+#include <limits.h>
+#include <stdlib.h>
+#include <regex.h>
+
+#include "utils.h"
+
+static char *regatoi(const regex_t *, char *, int);
+
+static const struct rerr {
+ int code;
+ char *name;
+ char *explain;
+} rerrs[] = {
+ { REG_NOMATCH, "REG_NOMATCH", "regexec() failed to match" },
+ { REG_BADPAT, "REG_BADPAT", "invalid regular expression" },
+ { REG_ECOLLATE, "REG_ECOLLATE", "invalid collating element" },
+ { REG_ECTYPE, "REG_ECTYPE", "invalid character class" },
+ { REG_EESCAPE, "REG_EESCAPE", "trailing backslash (\\)" },
+ { REG_ESUBREG, "REG_ESUBREG", "invalid backreference number" },
+ { REG_EBRACK, "REG_EBRACK", "brackets ([ ]) not balanced" },
+ { REG_EPAREN, "REG_EPAREN", "parentheses not balanced" },
+ { REG_EBRACE, "REG_EBRACE", "braces not balanced" },
+ { REG_BADBR, "REG_BADBR", "invalid repetition count(s)" },
+ { REG_ERANGE, "REG_ERANGE", "invalid character range" },
+ { REG_ESPACE, "REG_ESPACE", "out of memory" },
+ { REG_BADRPT, "REG_BADRPT", "repetition-operator operand invalid" },
+ { REG_EMPTY, "REG_EMPTY", "empty (sub)expression" },
+ { REG_ASSERT, "REG_ASSERT", "\"can't happen\" -- you found a bug" },
+ { REG_INVARG, "REG_INVARG", "invalid argument to regex routine" },
+ { 0, "", "*** unknown regexp error code ***" }
+};
+
+/*
+ - regerror - the interface to error numbers
+ = extern size_t regerror(int, const regex_t *, char *, size_t);
+ */
+/* ARGSUSED */
+size_t
+regerror(int errcode, const regex_t *preg, char *errbuf, size_t errbuf_size)
+{
+ struct rerr *r;
+ size_t len;
+ int target = errcode &~ REG_ITOA;
+ char *s;
+ char convbuf[50];
+
+ if (errcode == REG_ATOI)
+ s = regatoi(preg, convbuf, sizeof convbuf);
+ else {
+ for (r = rerrs; r->code != 0; r++)
+ if (r->code == target)
+ break;
+
+ if (errcode®_ITOA) {
+ if (r->code != 0) {
+ assert(strlen(r->name) < sizeof(convbuf));
+ (void) strlcpy(convbuf, r->name, sizeof convbuf);
+ } else
+ (void)snprintf(convbuf, sizeof convbuf,
+ "REG_0x%x", target);
+ s = convbuf;
+ } else
+ s = r->explain;
+ }
+
+ len = strlen(s) + 1;
+ if (errbuf_size > 0) {
+ strlcpy(errbuf, s, errbuf_size);
+ }
+
+ return(len);
+}
+
+/*
+ - regatoi - internal routine to implement REG_ATOI
+ */
+static char *
+regatoi(const regex_t *preg, char *localbuf, int localbufsize)
+{
+ struct rerr *r;
+
+ for (r = rerrs; r->code != 0; r++)
+ if (strcmp(r->name, preg->re_endp) == 0)
+ break;
+ if (r->code == 0)
+ return("0");
+
+ (void)snprintf(localbuf, localbufsize, "%d", r->code);
+ return(localbuf);
+}