Add GNU extensions mempcpy and wmemcpy.

Used by elfutils. On the bright side, they stopped using __mempcpy.

Bug: 18374026
Change-Id: Id29bbe6ef1c5ed5a171bb6c32182f129d8332abb

libc/Android.mk

@@ -143,6 +143,7 @@ libc_bionic_ndk_src_files := \
     bionic/mbrtoc16.cpp \
     bionic/mbrtoc32.cpp \
     bionic/mbstate.cpp \
+    bionic/mempcpy.cpp \
     bionic/mkdir.cpp \
     bionic/mkfifo.cpp \
     bionic/mknod.cpp \
@@ -214,6 +215,7 @@ libc_bionic_ndk_src_files := \
     bionic/wait.cpp \
     bionic/wchar.cpp \
     bionic/wctype.cpp \
+    bionic/wmempcpy.cpp \
 
 libc_bionic_src_files :=
 

libc/bionic/mempcpy.cpp

@@ -0,0 +1,33 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * 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 OWNER 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 <string.h>
+
+void* mempcpy(void* dst, const void* src, size_t n) {
+  return reinterpret_cast<char*>(memcpy(dst, src, n)) + n;
+}

libc/bionic/wmempcpy.cpp

@@ -0,0 +1,33 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * 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 OWNER 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 <wchar.h>
+
+wchar_t* wmempcpy(wchar_t* dst, const wchar_t* src, size_t n) {
+  return wmemcpy(dst, src, n) + n;
+}

libc/include/string.h

@@ -44,6 +44,9 @@ extern void*  memchr(const void *, int, size_t) __purefunc;
 extern void*  memrchr(const void *, int, size_t) __purefunc;
 extern int    memcmp(const void *, const void *, size_t) __purefunc;
 extern void*  memcpy(void* __restrict, const void* __restrict, size_t);
+#if defined(__USE_GNU)
+extern void*  mempcpy(void* __restrict, const void* __restrict, size_t);
+#endif
 extern void*  memmove(void *, const void *, size_t);
 extern void*  memset(void *, int, size_t);
 extern void*  memmem(const void *, size_t, const void *, size_t) __purefunc;

libc/include/wchar.h

@@ -151,6 +151,9 @@ extern int               wcwidth(wchar_t);
 extern wchar_t          *wmemchr(const wchar_t *, wchar_t, size_t);
 extern int               wmemcmp(const wchar_t *, const wchar_t *, size_t);
 extern wchar_t          *wmemcpy(wchar_t *, const wchar_t *, size_t);
+#if defined(__USE_GNU)
+extern wchar_t          *wmempcpy(wchar_t *, const wchar_t *, size_t);
+#endif
 extern wchar_t          *wmemmove(wchar_t *, const wchar_t *, size_t);
 extern wchar_t          *wmemset(wchar_t *, wchar_t, size_t);
 extern int               wprintf(const wchar_t *, ...);

tests/string_test.cpp

@@ -1395,3 +1395,8 @@ TEST(string, strnlen_147048) {
   EXPECT_EQ(0U, strnlen(heap_src, 1024*1024*1024));
   delete[] heap_src;
 }
+
+TEST(string, mempcpy) {
+  char dst[6];
+  ASSERT_EQ(&dst[4], reinterpret_cast<char*>(mempcpy(dst, "hello", 4)));
+}

tests/wchar_test.cpp

@@ -667,3 +667,8 @@ TEST(wchar, wcstoull_l_EINVAL) {
   wcstoull_l(L"123", NULL, 37, LC_GLOBAL_LOCALE);
   ASSERT_EQ(EINVAL, errno);
 }
+
+TEST(wchar, wmempcpy) {
+  wchar_t dst[6];
+  ASSERT_EQ(&dst[4], wmempcpy(dst, L"hello", 4));
+}