Bug 5041514 Re-implement with Apache 2.0 license

Change-Id: I7c85f0c555b3fbe33865c298e8243d08d48cdeb8
diff --git a/include/share/alloc.h b/include/share/alloc.h
index 812aa69..2e92dd8 100644
--- a/include/share/alloc.h
+++ b/include/share/alloc.h
@@ -1,212 +1,72 @@
-/* alloc - Convenience routines for safely allocating memory
- * Copyright (C) 2007  Josh Coalson
+/*
+ * Copyright (C) 2011 The Android Open Source Project
  *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * Lesser General Public License for more details.
+ *      http://www.apache.org/licenses/LICENSE-2.0
  *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  */
 
-#ifndef FLAC__SHARE__ALLOC_H
-#define FLAC__SHARE__ALLOC_H
+#ifndef __SHARE_ALLOC_H_
+#define __SHARE_ALLOC_H_
 
-#if HAVE_CONFIG_H
-#  include <config.h>
-#endif
+#include <limits.h>
 
-/* WATCHOUT: for c++ you may have to #define __STDC_LIMIT_MACROS 1 real early
- * before #including this file,  otherwise SIZE_MAX might not be defined
- */
-
-#include <limits.h> /* for SIZE_MAX */
-#if !defined _MSC_VER && !defined __MINGW32__ && !defined __EMX__
-#include <stdint.h> /* for SIZE_MAX in case limits.h didn't get it */
-#endif
-#include <stdlib.h> /* for size_t, malloc(), etc */
-
-#ifndef SIZE_MAX
-# ifndef SIZE_T_MAX
-#  ifdef _MSC_VER
-#   define SIZE_T_MAX UINT_MAX
-#  else
-#   error
-#  endif
-# endif
-# define SIZE_MAX SIZE_T_MAX
-#endif
-
-#ifndef FLaC__INLINE
-#define FLaC__INLINE
-#endif
-
-/* avoid malloc()ing 0 bytes, see:
- * https://www.securecoding.cert.org/confluence/display/seccode/MEM04-A.+Do+not+make+assumptions+about+the+result+of+allocating+0+bytes?focusedCommentId=5407003
-*/
-static FLaC__INLINE void *safe_malloc_(size_t size)
+// malloc(n floor 1)
+static inline void *safe_malloc_(size_t n)
 {
-	/* malloc(0) is undefined; FLAC src convention is to always allocate */
-	if(!size)
-		size++;
-	return malloc(size);
+    // dlmalloc is already safe
+    return malloc(n);
 }
 
-static FLaC__INLINE void *safe_calloc_(size_t nmemb, size_t size)
+// malloc(n1 * n2) then memset to zero
+static inline void *safe_calloc_(size_t n1, size_t n2)
 {
-	if(!nmemb || !size)
-		return malloc(1); /* malloc(0) is undefined; FLAC src convention is to always allocate */
-	return calloc(nmemb, size);
+    // dlcalloc is already safe
+    return calloc(n1, n2);
 }
 
-/*@@@@ there's probably a better way to prevent overflows when allocating untrusted sums but this works for now */
-
-static FLaC__INLINE void *safe_malloc_add_2op_(size_t size1, size_t size2)
+// malloc(n1 + n2)
+static inline void *safe_malloc_add_2op_(size_t n1, size_t n2)
 {
-	size2 += size1;
-	if(size2 < size1)
-		return 0;
-	return safe_malloc_(size2);
+    unsigned long long n = n1 + n2;
+    size_t ns = n;
+    // check for overflow
+    return n == ns ? malloc(ns) : NULL;
 }
 
-static FLaC__INLINE void *safe_malloc_add_3op_(size_t size1, size_t size2, size_t size3)
+// malloc(n1 * n2)
+static inline void *safe_malloc_mul_2op_(size_t n1, size_t n2)
 {
-	size2 += size1;
-	if(size2 < size1)
-		return 0;
-	size3 += size2;
-	if(size3 < size2)
-		return 0;
-	return safe_malloc_(size3);
+    unsigned long long n = n1 * n2;
+    size_t ns = n;
+    // check for overflow
+    return n == ns ? malloc(ns) : NULL;
 }
 
-static FLaC__INLINE void *safe_malloc_add_4op_(size_t size1, size_t size2, size_t size3, size_t size4)
+// malloc(n1 * (n2 + n3))
+static inline void *safe_malloc_muladd2_(size_t n1, size_t n2, size_t n3)
 {
-	size2 += size1;
-	if(size2 < size1)
-		return 0;
-	size3 += size2;
-	if(size3 < size2)
-		return 0;
-	size4 += size3;
-	if(size4 < size3)
-		return 0;
-	return safe_malloc_(size4);
+    unsigned long long n = n1 * (n2 + n3);
+    size_t ns = n;
+    // check for overflow
+    return n == ns ? malloc(ns) : NULL;
 }
 
-static FLaC__INLINE void *safe_malloc_mul_2op_(size_t size1, size_t size2)
-#if 0
-needs support for cases where sizeof(size_t) != 4
+// realloc(ptr, n1 * n2)
+static inline void *safe_realloc_mul_2op_(void *ptr, size_t n1, size_t n2)
 {
-	/* could be faster #ifdef'ing off SIZEOF_SIZE_T */
-	if(sizeof(size_t) == 4) {
-		if ((double)size1 * (double)size2 < 4294967296.0)
-			return malloc(size1*size2);
-	}
-	return 0;
-}
-#else
-/* better? */
-{
-	if(!size1 || !size2)
-		return malloc(1); /* malloc(0) is undefined; FLAC src convention is to always allocate */
-	if(size1 > SIZE_MAX / size2)
-		return 0;
-	return malloc(size1*size2);
-}
-#endif
-
-static FLaC__INLINE void *safe_malloc_mul_3op_(size_t size1, size_t size2, size_t size3)
-{
-	if(!size1 || !size2 || !size3)
-		return malloc(1); /* malloc(0) is undefined; FLAC src convention is to always allocate */
-	if(size1 > SIZE_MAX / size2)
-		return 0;
-	size1 *= size2;
-	if(size1 > SIZE_MAX / size3)
-		return 0;
-	return malloc(size1*size3);
+    unsigned long long n = n1 * n2;
+    size_t ns = n;
+    // check for overflow
+    return n == ns ? realloc(ptr, ns) : NULL;
 }
 
-/* size1*size2 + size3 */
-static FLaC__INLINE void *safe_malloc_mul2add_(size_t size1, size_t size2, size_t size3)
-{
-	if(!size1 || !size2)
-		return safe_malloc_(size3);
-	if(size1 > SIZE_MAX / size2)
-		return 0;
-	return safe_malloc_add_2op_(size1*size2, size3);
-}
-
-/* size1 * (size2 + size3) */
-static FLaC__INLINE void *safe_malloc_muladd2_(size_t size1, size_t size2, size_t size3)
-{
-	if(!size1 || (!size2 && !size3))
-		return malloc(1); /* malloc(0) is undefined; FLAC src convention is to always allocate */
-	size2 += size3;
-	if(size2 < size3)
-		return 0;
-	return safe_malloc_mul_2op_(size1, size2);
-}
-
-static FLaC__INLINE void *safe_realloc_add_2op_(void *ptr, size_t size1, size_t size2)
-{
-	size2 += size1;
-	if(size2 < size1)
-		return 0;
-	return realloc(ptr, size2);
-}
-
-static FLaC__INLINE void *safe_realloc_add_3op_(void *ptr, size_t size1, size_t size2, size_t size3)
-{
-	size2 += size1;
-	if(size2 < size1)
-		return 0;
-	size3 += size2;
-	if(size3 < size2)
-		return 0;
-	return realloc(ptr, size3);
-}
-
-static FLaC__INLINE void *safe_realloc_add_4op_(void *ptr, size_t size1, size_t size2, size_t size3, size_t size4)
-{
-	size2 += size1;
-	if(size2 < size1)
-		return 0;
-	size3 += size2;
-	if(size3 < size2)
-		return 0;
-	size4 += size3;
-	if(size4 < size3)
-		return 0;
-	return realloc(ptr, size4);
-}
-
-static FLaC__INLINE void *safe_realloc_mul_2op_(void *ptr, size_t size1, size_t size2)
-{
-	if(!size1 || !size2)
-		return realloc(ptr, 0); /* preserve POSIX realloc(ptr, 0) semantics */
-	if(size1 > SIZE_MAX / size2)
-		return 0;
-	return realloc(ptr, size1*size2);
-}
-
-/* size1 * (size2 + size3) */
-static FLaC__INLINE void *safe_realloc_muladd2_(void *ptr, size_t size1, size_t size2, size_t size3)
-{
-	if(!size1 || (!size2 && !size3))
-		return realloc(ptr, 0); /* preserve POSIX realloc(ptr, 0) semantics */
-	size2 += size3;
-	if(size2 < size3)
-		return 0;
-	return safe_realloc_mul_2op_(ptr, size1, size2);
-}
-
-#endif
+#endif // __SHARE_ALLOC_H_