[NaCl SDK] Add realpath(3) implementation.

native_client_sdk/src/tests/nacl_io_test/syscalls_test.cc

+// Copyright (c) 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <errno.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+
+#include "gtest/gtest.h"
+
+#include "nacl_io/kernel_intercept.h"
+#include "nacl_io/kernel_proxy.h"
+
+using namespace nacl_io;
+
+namespace {
+
+class SyscallsTest : public ::testing::Test {
+ public:
+  SyscallsTest() {}
+
+  void SetUp() {
+    ASSERT_EQ(0, ki_push_state_for_testing());
+    ASSERT_EQ(0, ki_init(&kp_));
+    // Unmount the passthrough FS and mount a memfs.
+    EXPECT_EQ(0, kp_.umount("/"));
+    EXPECT_EQ(0, kp_.mount("", "/", "memfs", 0, NULL));
+  }
+
+  void TearDown() { ki_uninit(); }
+
+ protected:
+  KernelProxy kp_;
+};
+
+}  // namespace
+
+#if defined(__native_client__)
+
+TEST_F(SyscallsTest, Realpath) {
+  char buffer[PATH_MAX];
+
+  ASSERT_EQ(0, ki_mkdir("/foo", S_IREAD | S_IWRITE));

[Sam Clegg, 2014/05/21 23:39:21]

If you wrote these tests with everything happening under "/tmp" then you could
run the tests against linux's glibc to verify that your test cases are correct. 
(or maybe you did that already?).

[binji, 2014/05/21 23:56:01]

Hm, good idea. I thought I needed write access to root, but I just need absolute
paths. I'll give it a shot.

+  ASSERT_EQ(0, ki_mkdir("/foo/bar", S_IREAD | S_IWRITE));
+  int fd = ki_open("/foo/file", O_CREAT | O_RDWR);
+  ASSERT_GT(fd, -1);
+  ASSERT_EQ(0, ki_close(fd));
+
+  // Test absolute paths.
+  EXPECT_STREQ("/", realpath("/", buffer));
+  EXPECT_STREQ("/", realpath("/foo/..", buffer));
+  EXPECT_STREQ("/foo", realpath("/foo", buffer));
+  EXPECT_STREQ("/foo", realpath("/foo/", buffer));
+  EXPECT_STREQ("/foo", realpath("/foo/bar/..", buffer));
+  EXPECT_STREQ("/foo", realpath("/foo/bar/../bar/../../foo", buffer));
+  EXPECT_STREQ("/foo", realpath("/foo/././", buffer));
+  EXPECT_STREQ("/foo", realpath("///foo", buffer));
+  EXPECT_STREQ("/foo/bar", realpath("/foo/bar", buffer));
+
+  EXPECT_EQ(NULL, realpath("/blah", buffer));
+  EXPECT_EQ(ENOENT, errno);
+
+  EXPECT_EQ(NULL, realpath("/blah/blah", buffer));
+  EXPECT_EQ(ENOENT, errno);
+
+  EXPECT_EQ(NULL, realpath("/foo/baz/..", buffer));
+  EXPECT_EQ(ENOENT, errno);
+
+  EXPECT_EQ(NULL, realpath("/foo/file/", buffer));
+  EXPECT_EQ(ENOTDIR, errno);
+
+  EXPECT_EQ(NULL, realpath(NULL, buffer));
+  EXPECT_EQ(EINVAL, errno);
+
+  // Test relative paths.
+  EXPECT_EQ(0, ki_chdir("/foo"));
+
+  EXPECT_STREQ("/", realpath("..", buffer));
+  EXPECT_STREQ("/foo", realpath(".", buffer));
+  EXPECT_STREQ("/foo", realpath("./", buffer));
+  EXPECT_STREQ("/foo", realpath("bar/..", buffer));
+  EXPECT_STREQ("/foo", realpath("bar/../../foo", buffer));
+  EXPECT_STREQ("/foo", realpath(".///", buffer));
+  EXPECT_STREQ("/foo/bar", realpath("bar", buffer));
+
+  // Test when resolved_path is allocated.
+  char* allocated = realpath("/foo", NULL);
+  EXPECT_STREQ("/foo", allocated);
+  free(allocated);
+}
+
+#endif  // defined(__native_client__)