Implement mblen(3).

Change-Id: I65948ea5b9ecd63f966ba767ad6db4a2effc4700

14 files changed, 74 insertions, 8 deletions

diff --git a/libc/Android.mk b/libc/Android.mk
index 374ffa65a..ac7cd7535 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -133,6 +133,7 @@ libc_bionic_ndk_src_files := \
     bionic/lockf.cpp \
     bionic/lstat.cpp \
     bionic/malloc_info.cpp \
+    bionic/mblen.cpp \
     bionic/mbrtoc16.cpp \
     bionic/mbrtoc32.cpp \
     bionic/mbstate.cpp \
diff --git a/libc/bionic/mblen.cpp b/libc/bionic/mblen.cpp
new file mode 100644
index 000000000..7def6f138
--- /dev/null
+++ b/libc/bionic/mblen.cpp
@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) 2016 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 <stdlib.h>
+#include <wchar.h>
+
+int mblen(const char* s, size_t n) {
+  mbstate_t state = {};
+  return mbrlen(s, n, &state);
+}
diff --git a/libc/include/stdlib.h b/libc/include/stdlib.h
index 2abaec396..ba4b14986 100644
--- a/libc/include/stdlib.h
+++ b/libc/include/stdlib.h
@@ -162,14 +162,11 @@ extern lldiv_t   lldiv(long long, long long) __pure2;
 extern const char* getprogname(void);
 extern void setprogname(const char*);
 
-/* make STLPort happy */
-extern int      mblen(const char *, size_t) __UNAVAILABLE;
-extern size_t   mbstowcs(wchar_t *, const char *, size_t);
-extern int      mbtowc(wchar_t *, const char *, size_t);
-
-/* Likewise, make libstdc++-v3 happy.  */
-extern int	wctomb(char *, wchar_t);
-extern size_t	wcstombs(char *, const wchar_t *, size_t);
+int mblen(const char*, size_t);
+size_t mbstowcs(wchar_t*, const char*, size_t);
+int mbtowc(wchar_t*, const char*, size_t);
+int wctomb(char*, wchar_t);
+size_t wcstombs(char*, const wchar_t*, size_t);
 
 extern size_t __ctype_get_mb_cur_max(void);
 #define MB_CUR_MAX __ctype_get_mb_cur_max()
diff --git a/libc/libc.arm.brillo.map b/libc/libc.arm.brillo.map
index 3e78e307c..a1373d899 100644
--- a/libc/libc.arm.brillo.map
+++ b/libc/libc.arm.brillo.map
@@ -1279,6 +1279,7 @@ LIBC_O {
     getpwent;
     getsubopt;
     hasmntopt;
+    mblen;
     pthread_getname_np;
     quotactl;
     setdomainname;
diff --git a/libc/libc.arm.map b/libc/libc.arm.map
index 420cd7e30..4e69bf112 100644
--- a/libc/libc.arm.map
+++ b/libc/libc.arm.map
@@ -1279,6 +1279,7 @@ LIBC_O {
     getpwent;
     getsubopt;
     hasmntopt;
+    mblen;
     pthread_getname_np;
     quotactl;
     setdomainname;
diff --git a/libc/libc.arm64.map b/libc/libc.arm64.map
index bdde35eee..7ea74a672 100644
--- a/libc/libc.arm64.map
+++ b/libc/libc.arm64.map
@@ -1201,6 +1201,7 @@ LIBC_O {
     getpwent;
     getsubopt;
     hasmntopt;
+    mblen;
     pthread_getname_np;
     quotactl;
     setdomainname;
diff --git a/libc/libc.map.txt b/libc/libc.map.txt
index be37ffbd3..8d1a1f9d0 100644
--- a/libc/libc.map.txt
+++ b/libc/libc.map.txt
@@ -1304,6 +1304,7 @@ LIBC_O {
     getpwent;
     getsubopt;
     hasmntopt;
+    mblen;
     pthread_getname_np;
     quotactl;
     setdomainname;
diff --git a/libc/libc.mips.brillo.map b/libc/libc.mips.brillo.map
index 6b5744cab..aac1d8ced 100644
--- a/libc/libc.mips.brillo.map
+++ b/libc/libc.mips.brillo.map
@@ -1263,6 +1263,7 @@ LIBC_O {
     getpwent;
     getsubopt;
     hasmntopt;
+    mblen;
     pthread_getname_np;
     quotactl;
     setdomainname;
diff --git a/libc/libc.mips.map b/libc/libc.mips.map
index 6ee9cf586..e514aa135 100644
--- a/libc/libc.mips.map
+++ b/libc/libc.mips.map
@@ -1263,6 +1263,7 @@ LIBC_O {
     getpwent;
     getsubopt;
     hasmntopt;
+    mblen;
     pthread_getname_np;
     quotactl;
     setdomainname;
diff --git a/libc/libc.mips64.map b/libc/libc.mips64.map
index bdde35eee..7ea74a672 100644
--- a/libc/libc.mips64.map
+++ b/libc/libc.mips64.map
@@ -1201,6 +1201,7 @@ LIBC_O {
     getpwent;
     getsubopt;
     hasmntopt;
+    mblen;
     pthread_getname_np;
     quotactl;
     setdomainname;
diff --git a/libc/libc.x86.brillo.map b/libc/libc.x86.brillo.map
index d483d3e55..f14861d30 100644
--- a/libc/libc.x86.brillo.map
+++ b/libc/libc.x86.brillo.map
@@ -1261,6 +1261,7 @@ LIBC_O {
     getpwent;
     getsubopt;
     hasmntopt;
+    mblen;
     pthread_getname_np;
     quotactl;
     setdomainname;
diff --git a/libc/libc.x86.map b/libc/libc.x86.map
index f0679c052..f6b6ea1ed 100644
--- a/libc/libc.x86.map
+++ b/libc/libc.x86.map
@@ -1261,6 +1261,7 @@ LIBC_O {
     getpwent;
     getsubopt;
     hasmntopt;
+    mblen;
     pthread_getname_np;
     quotactl;
     setdomainname;
diff --git a/libc/libc.x86_64.map b/libc/libc.x86_64.map
index bdde35eee..7ea74a672 100644
--- a/libc/libc.x86_64.map
+++ b/libc/libc.x86_64.map
@@ -1201,6 +1201,7 @@ LIBC_O {
     getpwent;
     getsubopt;
     hasmntopt;
+    mblen;
     pthread_getname_np;
     quotactl;
     setdomainname;
diff --git a/tests/stdlib_test.cpp b/tests/stdlib_test.cpp
index 05438eb17..773230f2f 100644
--- a/tests/stdlib_test.cpp
+++ b/tests/stdlib_test.cpp
@@ -537,3 +537,26 @@ TEST(stdlib, getsubopt) {
 
   ASSERT_EQ(-1, getsubopt(&subopts, tokens, &value));
 }
+
+TEST(stdlib, mblen) {
+  // "If s is a null pointer, mblen() shall return a non-zero or 0 value, if character encodings,
+  // respectively, do or do not have state-dependent encodings." We're always UTF-8.
+  EXPECT_EQ(0, mblen(nullptr, 1));
+
+  ASSERT_STREQ("C.UTF-8", setlocale(LC_ALL, "C.UTF-8"));
+
+  // 1-byte UTF-8.
+  EXPECT_EQ(1, mblen("abcdef", 6));
+  // 2-byte UTF-8.
+  EXPECT_EQ(2, mblen("\xc2\xa2" "cdef", 6));
+  // 3-byte UTF-8.
+  EXPECT_EQ(3, mblen("\xe2\x82\xac" "def", 6));
+  // 4-byte UTF-8.
+  EXPECT_EQ(4, mblen("\xf0\xa4\xad\xa2" "ef", 6));
+
+  // Illegal over-long sequence.
+  ASSERT_EQ(-1, mblen("\xf0\x82\x82\xac" "ef", 6));
+
+  // "mblen() shall ... return 0 (if s points to the null byte)".
+  EXPECT_EQ(0, mblen("", 1));
+}