Move realpath.c to upstream-freebsd.

This is actually a slightly newer upstream version than the one I
originally pulled. Hopefully now it's in upstream-freebsd it will
be easier to track upstream, though I still need to sit down and
write the necessary scripts at some point.

Bug: 5110679
Change-Id: I87e563f0f95aa8e68b45578e2a8f448bbf827a33

6 files changed, 155 insertions, 14 deletions

diff --git a/libc/Android.mk b/libc/Android.mk
index 72192117f..a8b4ebdd5 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -195,7 +195,6 @@ libc_common_src_files := \
 	bionic/ptsname_r.c \
 	bionic/pututline.c \
 	bionic/pwrite.c \
-	bionic/realpath.c \
 	bionic/reboot.c \
 	bionic/recv.c \
 	bionic/sched_cpualloc.c \
@@ -317,6 +316,9 @@ libc_bionic_src_files := \
     bionic/__vsprintf_chk.cpp \
     bionic/wchar.cpp \
 
+libc_upstream_freebsd_src_files := \
+    upstream-freebsd/lib/libc/stdlib/realpath.c \
+
 libc_upstream_netbsd_src_files := \
     upstream-netbsd/common/lib/libc/hash/sha1/sha1.c \
     upstream-netbsd/common/lib/libc/inet/inet_addr.c \
@@ -745,6 +747,29 @@ include $(BUILD_STATIC_LIBRARY)
 
 
 # ========================================================
+# libc_freebsd.a - upstream FreeBSD C library code
+# ========================================================
+#
+# These files are built with the freebsd-compat.h header file
+# automatically included.
+
+include $(CLEAR_VARS)
+
+LOCAL_SRC_FILES := $(libc_upstream_freebsd_src_files)
+LOCAL_CFLAGS := \
+    $(libc_common_cflags) \
+    -I$(LOCAL_PATH)/upstream-freebsd \
+    -I$(LOCAL_PATH)/upstream-freebsd/libc/include \
+    -include upstream-freebsd/freebsd-compat.h
+LOCAL_C_INCLUDES := $(libc_common_c_includes)
+LOCAL_MODULE := libc_freebsd
+LOCAL_ADDITIONAL_DEPENDENCIES := $(LOCAL_PATH)/Android.mk
+LOCAL_SYSTEM_SHARED_LIBRARIES :=
+
+include $(BUILD_STATIC_LIBRARY)
+
+
+# ========================================================
 # libc_netbsd.a - upstream NetBSD C library code
 # ========================================================
 #
@@ -796,7 +821,7 @@ LOCAL_CFLAGS := $(libc_common_cflags) \
 LOCAL_C_INCLUDES := $(libc_common_c_includes)
 LOCAL_MODULE := libc_common
 LOCAL_ADDITIONAL_DEPENDENCIES := $(LOCAL_PATH)/Android.mk
-LOCAL_WHOLE_STATIC_LIBRARIES := libbionic_ssp libc_bionic libc_netbsd
+LOCAL_WHOLE_STATIC_LIBRARIES := libbionic_ssp libc_bionic libc_freebsd libc_netbsd
 LOCAL_SYSTEM_SHARED_LIBRARIES :=
 
 include $(BUILD_STATIC_LIBRARY)
diff --git a/libc/upstream-freebsd/freebsd-compat.h b/libc/upstream-freebsd/freebsd-compat.h
new file mode 100644
index 000000000..08dec1529
--- /dev/null
+++ b/libc/upstream-freebsd/freebsd-compat.h
@@ -0,0 +1,20 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef _BIONIC_FREEBSD_COMPAT_H_included
+#define _BIONIC_FREEBSD_COMPAT_H_included
+
+#endif
diff --git a/libc/bionic/realpath.c b/libc/upstream-freebsd/lib/libc/stdlib/realpath.c
index b9098319a..8fd5457af 100644
--- a/libc/bionic/realpath.c
+++ b/libc/upstream-freebsd/lib/libc/stdlib/realpath.c
@@ -30,8 +30,9 @@
 static char sccsid[] = "@(#)realpath.c	8.1 (Berkeley) 2/16/94";
 #endif /* LIBC_SCCS and not lint */
 #include <sys/cdefs.h>
-__FBSDID("$FreeBSD: release/9.0.0/lib/libc/stdlib/realpath.c 217144 2011-01-08 11:04:30Z kib $");
+__FBSDID("$FreeBSD$");
 
+#include "namespace.h"
 #include <sys/param.h>
 #include <sys/stat.h>
 
@@ -39,6 +40,7 @@ __FBSDID("$FreeBSD: release/9.0.0/lib/libc/stdlib/realpath.c 217144 2011-01-08 1
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
+#include "un-namespace.h"
 
 /*
  * Find the real name of path, by removing all ".", ".." and symlink
@@ -52,7 +54,7 @@ realpath(const char * __restrict path, char * __restrict resolved)
 	char *p, *q, *s;
 	size_t left_len, resolved_len;
 	unsigned symlinks;
-	int m, serrno, slen;
+	int m, slen;
 	char left[PATH_MAX], next_token[PATH_MAX], symlink[PATH_MAX];
 
 	if (path == NULL) {
@@ -63,7 +65,6 @@ realpath(const char * __restrict path, char * __restrict resolved)
 		errno = ENOENT;
 		return (NULL);
 	}
-	serrno = errno;
 	if (resolved == NULL) {
 		resolved = malloc(PATH_MAX);
 		if (resolved == NULL)
@@ -130,8 +131,29 @@ realpath(const char * __restrict path, char * __restrict resolved)
 			resolved[resolved_len++] = '/';
 			resolved[resolved_len] = '\0';
 		}
-		if (next_token[0] == '\0')
+		if (next_token[0] == '\0') {
+			/*
+			 * Handle consequential slashes.  The path
+			 * before slash shall point to a directory.
+			 *
+			 * Only the trailing slashes are not covered
+			 * by other checks in the loop, but we verify
+			 * the prefix for any (rare) "//" or "/\0"
+			 * occurence to not implement lookahead.
+			 */
+			if (lstat(resolved, &sb) != 0) {
+				if (m)
+					free(resolved);
+				return (NULL);
+			}
+			if (!S_ISDIR(sb.st_mode)) {
+				if (m)
+					free(resolved);
+				errno = ENOTDIR;
+				return (NULL);
+			}
 			continue;
+		}
 		else if (strcmp(next_token, ".") == 0)
 			continue;
 		else if (strcmp(next_token, "..") == 0) {
@@ -149,9 +171,7 @@ realpath(const char * __restrict path, char * __restrict resolved)
 		}
 
 		/*
-		 * Append the next path component and lstat() it. If
-		 * lstat() fails we still can return successfully if
-		 * there are no more path components left.
+		 * Append the next path component and lstat() it.
 		 */
 		resolved_len = strlcat(resolved, next_token, PATH_MAX);
 		if (resolved_len >= PATH_MAX) {
@@ -161,10 +181,6 @@ realpath(const char * __restrict path, char * __restrict resolved)
 			return (NULL);
 		}
 		if (lstat(resolved, &sb) != 0) {
-			if (errno == ENOENT && p == NULL) {
-				errno = serrno;
-				return (resolved);
-			}
 			if (m)
 				free(resolved);
 			return (NULL);
@@ -210,7 +226,8 @@ realpath(const char * __restrict path, char * __restrict resolved)
 					symlink[slen] = '/';
 					symlink[slen + 1] = 0;
 				}
-				left_len = strlcat(symlink, left, sizeof(left));
+				left_len = strlcat(symlink, left,
+				    sizeof(symlink));
 				if (left_len >= sizeof(left)) {
 					if (m)
 						free(resolved);
diff --git a/libc/upstream-freebsd/namespace.h b/libc/upstream-freebsd/namespace.h
new file mode 100644
index 000000000..a3f850ef6
--- /dev/null
+++ b/libc/upstream-freebsd/namespace.h
@@ -0,0 +1,20 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ *
+ * 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
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * 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 _BIONIC_FREEBSD_NAMESPACE_H_included
+#define _BIONIC_FREEBSD_NAMESPACE_H_included
+
+#endif
diff --git a/libc/upstream-freebsd/un-namespace.h b/libc/upstream-freebsd/un-namespace.h
new file mode 100644
index 000000000..a3f850ef6
--- /dev/null
+++ b/libc/upstream-freebsd/un-namespace.h
@@ -0,0 +1,20 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ *
+ * 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
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * 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 _BIONIC_FREEBSD_NAMESPACE_H_included
+#define _BIONIC_FREEBSD_NAMESPACE_H_included
+
+#endif
diff --git a/tests/stdlib_test.cpp b/tests/stdlib_test.cpp
index 8735100d4..fed39f87b 100644
--- a/tests/stdlib_test.cpp
+++ b/tests/stdlib_test.cpp
@@ -17,6 +17,8 @@
 #include <gtest/gtest.h>
 
 #include <errno.h>
+#include <libgen.h>
+#include <limits.h>
 #include <stdint.h>
 #include <stdlib.h>
 
@@ -70,3 +72,40 @@ TEST(stdlib, posix_memalign) {
   // Can't align to a non-power of 2.
   ASSERT_EQ(EINVAL, posix_memalign(&p, 81, 128));
 }
+
+TEST(stdlib, realpath__NULL_filename) {
+  errno = 0;
+  char* p = realpath(NULL, NULL);
+  ASSERT_TRUE(p == NULL);
+  ASSERT_EQ(EINVAL, errno);
+}
+
+TEST(stdlib, realpath__empty_filename) {
+  errno = 0;
+  char* p = realpath("", NULL);
+  ASSERT_TRUE(p == NULL);
+  ASSERT_EQ(ENOENT, errno);
+}
+
+TEST(stdlib, realpath__ENOENT) {
+  errno = 0;
+  char* p = realpath("/this/directory/path/almost/certainly/does/not/exist", NULL);
+  ASSERT_TRUE(p == NULL);
+  ASSERT_EQ(ENOENT, errno);
+}
+
+TEST(stdlib, realpath) {
+  // Get the name of this executable.
+  char executable_path[PATH_MAX];
+  int rc = readlink("/proc/self/exe", executable_path, sizeof(executable_path));
+  ASSERT_NE(rc, -1);
+  executable_path[rc] = '\0';
+
+  char buf[PATH_MAX + 1];
+  char* p = realpath("/proc/self/exe", buf);
+  ASSERT_STREQ(executable_path, p);
+
+  p = realpath("/proc/self/exe", NULL);
+  ASSERT_STREQ(executable_path, p);
+  free(p);
+}