Sync with upstream NetBSD lib/libc/regex.

Bug: http://b/22850181
(cherry-picked from commit 71927a82379f7a72559ea96e6678d6215090937f)

Change-Id: I11a51a2031e68a953ccd5691da98c699c7d01904
diff --git a/libc/Android.mk b/libc/Android.mk
index 9610c14..984187f 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -349,6 +349,7 @@
     upstream-netbsd/libc/stdlib/mrand48.c \
     upstream-netbsd/libc/stdlib/nrand48.c \
     upstream-netbsd/libc/stdlib/_rand48.c \
+    upstream-netbsd/libc/stdlib/reallocarr.c \
     upstream-netbsd/libc/stdlib/seed48.c \
     upstream-netbsd/libc/stdlib/srand48.c \
     upstream-netbsd/libc/stdlib/tdelete.c \
diff --git a/libc/upstream-netbsd/libc/regex/regcomp.c b/libc/upstream-netbsd/libc/regex/regcomp.c
index 2644a22..6af9734 100644
--- a/libc/upstream-netbsd/libc/regex/regcomp.c
+++ b/libc/upstream-netbsd/libc/regex/regcomp.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: regcomp.c,v 1.33 2012/03/13 21:13:43 christos Exp $	*/
+/*	$NetBSD: regcomp.c,v 1.36 2015/09/12 19:08:47 christos Exp $	*/
 
 /*-
  * Copyright (c) 1992, 1993, 1994
@@ -76,7 +76,7 @@
 #if 0
 static char sccsid[] = "@(#)regcomp.c	8.5 (Berkeley) 3/20/94";
 #else
-__RCSID("$NetBSD: regcomp.c,v 1.33 2012/03/13 21:13:43 christos Exp $");
+__RCSID("$NetBSD: regcomp.c,v 1.36 2015/09/12 19:08:47 christos Exp $");
 #endif
 #endif /* LIBC_SCCS and not lint */
 
@@ -262,12 +262,11 @@
 		len = strlen(pattern);
 
 	/* do the mallocs early so failure handling is easy */
-	g = (struct re_guts *)malloc(sizeof(struct re_guts) +
-							(NC-1)*sizeof(cat_t));
+	g = malloc(sizeof(struct re_guts) + (NC - 1) * sizeof(cat_t));
 	if (g == NULL)
 		return(REG_ESPACE);
 	p->ssize = len/(size_t)2*(size_t)3 + (size_t)1;	/* ugh */
-	p->strip = malloc(p->ssize * sizeof(sop));
+	p->strip = calloc(p->ssize, sizeof(sop));
 	p->slen = 0;
 	if (p->strip == NULL) {
 		free(g);
@@ -1075,19 +1074,19 @@
     int ch)
 {
 	cat_t *cap;
+	unsigned char uc = (unsigned char)ch;
 
 	_DIAGASSERT(p != NULL);
 
 	cap = p->g->categories;
-	if ((p->g->cflags&REG_ICASE) && isalpha((unsigned char) ch)
-	    && othercase((unsigned char) ch) != (unsigned char) ch)
-		bothcases(p, (unsigned char) ch);
+	if ((p->g->cflags & REG_ICASE) && isalpha(uc) && othercase(uc) != uc)
+		bothcases(p, uc);
 	else {
-		EMIT(OCHAR, (sopno)(unsigned char)ch);
-		if (cap[ch] == 0) {
+		EMIT(OCHAR, (sopno)uc);
+		if (cap[uc] == 0) {
 			_DIAGASSERT(__type_fit(unsigned char,
 			    p->g->ncategories + 1));
-			cap[ch] = (unsigned char)p->g->ncategories++;
+			cap[uc] = (unsigned char)p->g->ncategories++;
 		}
 	}
 }
@@ -1236,6 +1235,7 @@
 	cset *cs;
 	size_t css;
 	size_t i;
+	void *old_ptr;
 
 	_DIAGASSERT(p != NULL);
 
@@ -1248,28 +1248,18 @@
 		nbytes = nc / CHAR_BIT * css;
 		if (MEMSIZE(p) > MEMLIMIT)
 			goto oomem;
-		if (p->g->sets == NULL)
-			p->g->sets = malloc(nc * sizeof(cset));
-		else
-			p->g->sets = realloc(p->g->sets, nc * sizeof(cset));
-		if (p->g->setbits == NULL)
-			p->g->setbits = malloc(nbytes);
-		else {
-			p->g->setbits = realloc(p->g->setbits, nbytes);
-			/* xxx this isn't right if setbits is now NULL */
+		if (reallocarr(&p->g->sets, nc, sizeof(cset)))
+			goto oomem;
+		old_ptr = p->g->setbits;
+		if (reallocarr(&p->g->setbits, nc / CHAR_BIT, css)) {
+			free(old_ptr);
+			goto oomem;
+		}
+		if (old_ptr != p->g->setbits) {
 			for (i = 0; i < no; i++)
 				p->g->sets[i].ptr = p->g->setbits + css*(i/CHAR_BIT);
 		}
-		if (p->g->sets != NULL && p->g->setbits != NULL)
-			(void) memset((char *)p->g->setbits + (nbytes - css),
-								0, css);
-		else {
-oomem:
-			no = 0;
-			SETERROR(REG_ESPACE);
-			/* caller's responsibility not to do set ops */
-			return NULL;
-		}
+		(void) memset((char *)p->g->setbits + (nbytes - css), 0, css);
 	}
 
 	cs = &p->g->sets[no];
@@ -1280,6 +1270,11 @@
 	cs->multis = NULL;
 
 	return(cs);
+
+oomem:
+	SETERROR(REG_ESPACE);
+	/* caller's responsibility not to do set ops */
+	return NULL;
 }
 
 /*
@@ -1763,30 +1758,18 @@
  == static void enlarge(struct parse *p, sopno size);
  */
 static int
-enlarge(
-    struct parse *p,
-    sopno size)
+enlarge(struct parse *p, sopno size)
 {
-	sop *sp;
-	sopno osize;
-
 	_DIAGASSERT(p != NULL);
 
 	if (p->ssize >= size)
 		return 1;
 
-	osize = p->ssize;
-	p->ssize = size;
-	if (MEMSIZE(p) > MEMLIMIT)
-		goto oomem;
-	sp = realloc(p->strip, p->ssize * sizeof(sop));
-	if (sp == NULL) {
-oomem:
-		p->ssize = osize;
+	if (MEMSIZE(p) > MEMLIMIT || reallocarr(&p->strip, size, sizeof(sop))) {
 		SETERROR(REG_ESPACE);
 		return 0;
 	}
-	p->strip = sp;
+	p->ssize = size;
 	return 1;
 }
 
@@ -1804,11 +1787,9 @@
 	_DIAGASSERT(g != NULL);
 
 	g->nstates = p->slen;
-	g->strip = realloc(p->strip, p->slen * sizeof(sop));
-	if (g->strip == NULL) {
-		SETERROR(REG_ESPACE);
-		g->strip = p->strip;
-	}
+	g->strip = p->strip;
+	reallocarr(&g->strip, p->slen, sizeof(sop));
+	/* Ignore error as tries to free memory only. */
 }
 
 /*
diff --git a/libc/upstream-netbsd/libc/stdlib/reallocarr.c b/libc/upstream-netbsd/libc/stdlib/reallocarr.c
new file mode 100644
index 0000000..6ffe811
--- /dev/null
+++ b/libc/upstream-netbsd/libc/stdlib/reallocarr.c
@@ -0,0 +1,95 @@
+/* $NetBSD: reallocarr.c,v 1.5 2015/08/20 22:27:49 kamil Exp $ */
+
+/*-
+ * Copyright (c) 2015 Joerg Sonnenberger <joerg@NetBSD.org>.
+ * All rights reserved.
+ *
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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
+ * COPYRIGHT HOLDERS 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.
+ */
+
+#if HAVE_NBTOOL_CONFIG_H
+#include "nbtool_config.h"
+#endif
+
+#include <sys/cdefs.h>
+__RCSID("$NetBSD: reallocarr.c,v 1.5 2015/08/20 22:27:49 kamil Exp $");
+
+#include "namespace.h"
+#include <errno.h>
+/* Old POSIX has SIZE_MAX in limits.h */
+#include <limits.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+#ifdef _LIBC
+#ifdef __weak_alias
+__weak_alias(reallocarr, _reallocarr)
+#endif
+#endif
+
+#define SQRT_SIZE_MAX (((size_t)1) << (sizeof(size_t) * CHAR_BIT / 2))
+
+#if !HAVE_REALLOCARR
+int
+reallocarr(void *ptr, size_t number, size_t size)
+{
+	int saved_errno, result;
+	void *optr;
+	void *nptr;
+
+	saved_errno = errno;
+	memcpy(&optr, ptr, sizeof(ptr));
+	if (number == 0 || size == 0) {
+		free(optr);
+		nptr = NULL;
+		memcpy(ptr, &nptr, sizeof(ptr));
+		errno = saved_errno;
+		return 0;
+	}
+
+	/*
+	 * Try to avoid division here.
+	 *
+	 * It isn't possible to overflow during multiplication if neither
+	 * operand uses any of the most significant half of the bits.
+	 */
+	if (__predict_false((number|size) >= SQRT_SIZE_MAX &&
+	                    number > SIZE_MAX / size)) {
+		errno = saved_errno;
+		return EOVERFLOW;
+	}
+
+	nptr = realloc(optr, number * size);
+	if (__predict_false(nptr == NULL)) {
+		result = errno;
+	} else {
+		result = 0;
+		memcpy(ptr, &nptr, sizeof(ptr));
+	}
+	errno = saved_errno;
+	return result;
+}
+#endif
diff --git a/libc/upstream-netbsd/netbsd-compat.h b/libc/upstream-netbsd/netbsd-compat.h
index e33885e..3ef19e1 100644
--- a/libc/upstream-netbsd/netbsd-compat.h
+++ b/libc/upstream-netbsd/netbsd-compat.h
@@ -33,4 +33,7 @@
 #define __readlockenv() 0
 #define __unlockenv() 0
 
+#include <stddef.h>
+__LIBC_HIDDEN__ int reallocarr(void*, size_t, size_t);
+
 #endif