Reimplement remove(3) without the lstat(2).

This assumes that it's more likely we're unlinking a file than a directory,
though even if that's not true, as long as a failed unlink(2) is cheaper
than a successful lstat(2) -- which seems likely since there's no data to
copy -- we still win.

Change-Id: I0210e9cd3d31b8cf1813c55c810262ef327382ed

diff --git a/libc/Android.bp b/libc/Android.bp
index 592c401..0a76e87 100644 (file)
--- a/libc/Android.bp
+++ b/libc/Android.bp
@@ -440,7 +440,6 @@ cc_library_static {
         "upstream-openbsd/lib/libc/stdio/open_wmemstream.c",
         "upstream-openbsd/lib/libc/stdio/perror.c",
         "upstream-openbsd/lib/libc/stdio/puts.c",
-        "upstream-openbsd/lib/libc/stdio/remove.c",
         "upstream-openbsd/lib/libc/stdio/rget.c",
         "upstream-openbsd/lib/libc/stdio/setvbuf.c",
         "upstream-openbsd/lib/libc/stdio/sscanf.c",

diff --git a/libc/stdio/stdio.cpp b/libc/stdio/stdio.cpp
index 53b3fae..23a54de 100644 (file)
--- a/libc/stdio/stdio.cpp
+++ b/libc/stdio/stdio.cpp
@@ -741,6 +741,12 @@ wint_t putwchar(wchar_t wc) {
   return fputwc(wc, stdout);
 }
 
+int remove(const char* path) {
+  if (unlink(path) != -1) return 0;
+  if (errno != EISDIR) return -1;
+  return rmdir(path);
+}
+
 void rewind(FILE* fp) {
   ScopedFileLock sfl(fp);
   fseek(fp, 0, SEEK_SET);

diff --git a/libc/upstream-openbsd/lib/libc/stdio/remove.c b/libc/upstream-openbsd/lib/libc/stdio/remove.c
deleted file mode 100644 (file)
index d09d76f..0000000
--- a/libc/upstream-openbsd/lib/libc/stdio/remove.c
+++ /dev/null
@@ -1,49 +0,0 @@
-/*     $OpenBSD: remove.c,v 1.7 2005/08/08 08:05:36 espie Exp $        */
-
-/*-
- * Copyright (c) 1990, 1993
- *     The Regents of the University of California.  All rights reserved.
- *
- * This code is derived from software contributed to Berkeley by
- * Chris Torek.
- *
- * 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.
- * 3. Neither the name of the University nor the names of its contributors
- *    may be used to endorse or promote products derived from this software
- *    without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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 <stdio.h>
-#include <unistd.h>
-#include <sys/stat.h>
-
-int
-remove(const char *file)
-{
-       struct stat st;
-
-       if (lstat(file, &st) < 0)
-               return (-1);
-       if (S_ISDIR(st.st_mode))
-               return (rmdir(file));
-       return (unlink(file));
-}

diff --git a/tests/stdio_test.cpp b/tests/stdio_test.cpp
index 636b504..8747dfc 100644 (file)
--- a/tests/stdio_test.cpp
+++ b/tests/stdio_test.cpp
@@ -1307,3 +1307,25 @@ TEST(STDIO_TEST, ctermid) {
   ASSERT_EQ(buf, ctermid(buf));
   ASSERT_STREQ("/dev/tty", buf);
 }
+
+TEST(STDIO_TEST, remove) {
+  struct stat sb;
+
+  TemporaryFile tf;
+  ASSERT_EQ(0, remove(tf.filename));
+  ASSERT_EQ(-1, lstat(tf.filename, &sb));
+  ASSERT_EQ(ENOENT, errno);
+
+  TemporaryDir td;
+  ASSERT_EQ(0, remove(td.dirname));
+  ASSERT_EQ(-1, lstat(td.dirname, &sb));
+  ASSERT_EQ(ENOENT, errno);
+
+  errno = 0;
+  ASSERT_EQ(-1, remove(tf.filename));
+  ASSERT_EQ(ENOENT, errno);
+
+  errno = 0;
+  ASSERT_EQ(-1, remove(td.dirname));
+  ASSERT_EQ(ENOENT, errno);
+}