1 files changed, 283 insertions, 0 deletions
diff --git a/xpcom/glue/tests/gtest/TestFileUtils.cpp b/xpcom/glue/tests/gtest/TestFileUtils.cpp
new file mode 100644
index 0000000000..55106c6c5f
--- /dev/null
+++ b/xpcom/glue/tests/gtest/TestFileUtils.cpp
@@ -0,0 +1,283 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+/* Test ReadSysFile() */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "FileUtils.h"
+
+#include "gtest/gtest.h"
+
+namespace mozilla {
+
+#ifdef ReadSysFile_PRESENT
+
+/**
+ * Create a file with the specified contents.
+ */
+static bool
+WriteFile(
+  const char* aFilename,
+  const void* aContents,
+  size_t aContentsLen)
+{
+  int fd;
+  ssize_t ret;
+  size_t offt;
+
+  fd = MOZ_TEMP_FAILURE_RETRY(
+    open(aFilename, O_WRONLY | O_CREAT | O_TRUNC, S_IRUSR | S_IWUSR));
+  if (fd == -1) {
+    fprintf(stderr, "open(): %s: %s\n", aFilename, strerror(errno));
+    return false;
+  }
+
+  offt = 0;
+  do {
+    ret = MOZ_TEMP_FAILURE_RETRY(
+      write(fd, (char*)aContents + offt, aContentsLen - offt));
+    if (ret == -1) {
+      fprintf(stderr, "write(): %s: %s\n", aFilename, strerror(errno));
+      close(fd);
+      return false;
+    }
+    offt += ret;
+  } while (offt < aContentsLen);
+
+  ret = MOZ_TEMP_FAILURE_RETRY(close(fd));
+  if (ret == -1) {
+    fprintf(stderr, "close(): %s: %s\n", aFilename, strerror(errno));
+    return false;
+  }
+  return true;
+}
+
+TEST(ReadSysFile, Nonexistent) {
+  bool ret;
+  int errno_saved;
+
+  ret = ReadSysFile("/nonexistent", nullptr, 0);
+  errno_saved = errno;
+
+  ASSERT_FALSE(ret);
+  ASSERT_EQ(errno_saved, ENOENT);
+}
+
+TEST(ReadSysFile, Main) {
+  /* Use a different file name for each test since different tests could be
+  executed concurrently. */
+  static const char* fn = "TestReadSysFileMain";
+  /* If we have a file which contains "abcd" and we read it with ReadSysFile(),
+  providing a buffer of size 10 bytes, we would expect 5 bytes to be written
+  to that buffer: "abcd\0". */
+  struct
+  {
+    /* input (file contents), e.g. "abcd" */
+    const char* input;
+    /* pretended output buffer size, e.g. 10; the actual buffer is larger
+    and we check if anything was written past the end of the allowed length */
+    size_t output_size;
+    /* expected number of bytes written to the output buffer, including the
+    terminating '\0', e.g. 5 */
+    size_t output_len;
+    /* expected output buffer contents, e.g. "abcd\0", the first output_len
+    bytes of the output buffer should match the first 'output_len' bytes from
+    'output', the rest of the output buffer should be untouched. */
+    const char* output;
+  } tests[] = {
+    /* No new lines */
+    {"", 0, 0, ""},
+    {"", 1, 1, "\0"}, /* \0 is redundant, but we write it for clarity */
+    {"", 9, 1, "\0"},
+
+    {"a", 0, 0, ""},
+    {"a", 1, 1, "\0"},
+    {"a", 2, 2, "a\0"},
+    {"a", 9, 2, "a\0"},
+
+    {"abcd", 0, 0, ""},
+    {"abcd", 1, 1, "\0"},
+    {"abcd", 2, 2, "a\0"},
+    {"abcd", 3, 3, "ab\0"},
+    {"abcd", 4, 4, "abc\0"},
+    {"abcd", 5, 5, "abcd\0"},
+    {"abcd", 9, 5, "abcd\0"},
+
+    /* A single trailing new line */
+    {"\n", 0, 0, ""},
+    {"\n", 1, 1, "\0"},
+    {"\n", 2, 1, "\0"},
+    {"\n", 9, 1, "\0"},
+
+    {"a\n", 0, 0, ""},
+    {"a\n", 1, 1, "\0"},
+    {"a\n", 2, 2, "a\0"},
+    {"a\n", 3, 2, "a\0"},
+    {"a\n", 9, 2, "a\0"},
+
+    {"abcd\n", 0, 0, ""},
+    {"abcd\n", 1, 1, "\0"},
+    {"abcd\n", 2, 2, "a\0"},
+    {"abcd\n", 3, 3, "ab\0"},
+    {"abcd\n", 4, 4, "abc\0"},
+    {"abcd\n", 5, 5, "abcd\0"},
+    {"abcd\n", 6, 5, "abcd\0"},
+    {"abcd\n", 9, 5, "abcd\0"},
+
+    /* Multiple trailing new lines */
+    {"\n\n", 0, 0, ""},
+    {"\n\n", 1, 1, "\0"},
+    {"\n\n", 2, 2, "\n\0"},
+    {"\n\n", 3, 2, "\n\0"},
+    {"\n\n", 9, 2, "\n\0"},
+
+    {"a\n\n", 0, 0, ""},
+    {"a\n\n", 1, 1, "\0"},
+    {"a\n\n", 2, 2, "a\0"},
+    {"a\n\n", 3, 3, "a\n\0"},
+    {"a\n\n", 4, 3, "a\n\0"},
+    {"a\n\n", 9, 3, "a\n\0"},
+
+    {"abcd\n\n", 0, 0, ""},
+    {"abcd\n\n", 1, 1, "\0"},
+    {"abcd\n\n", 2, 2, "a\0"},
+    {"abcd\n\n", 3, 3, "ab\0"},
+    {"abcd\n\n", 4, 4, "abc\0"},
+    {"abcd\n\n", 5, 5, "abcd\0"},
+    {"abcd\n\n", 6, 6, "abcd\n\0"},
+    {"abcd\n\n", 7, 6, "abcd\n\0"},
+    {"abcd\n\n", 9, 6, "abcd\n\0"},
+
+    /* New line in the middle */
+    {"ab\ncd", 9, 6, "ab\ncd\0"},
+  };
+
+  for (size_t i = 0; i < sizeof(tests) / sizeof(tests[0]); i++) {
+    ASSERT_TRUE(WriteFile(fn, tests[i].input, strlen(tests[i].input)));
+    /* Leave the file to exist if some of the assertions fail. */
+
+    char buf[128];
+    static const char unmodified = 'X';
+
+    memset(buf, unmodified, sizeof(buf));
+
+    ASSERT_TRUE(ReadSysFile(fn, buf, tests[i].output_size));
+
+    if (tests[i].output_size == 0) {
+      /* The buffer must be unmodified. We check only the first byte. */
+      ASSERT_EQ(unmodified, buf[0]);
+    } else {
+      ASSERT_EQ(tests[i].output_len, strlen(buf) + 1);
+      ASSERT_STREQ(tests[i].output, buf);
+      /* Check that the first byte after the trailing '\0' has not been
+      modified. */
+      ASSERT_EQ(unmodified, buf[tests[i].output_len]);
+    }
+  }
+
+  unlink(fn);
+}
+
+TEST(ReadSysFile, Int) {
+  static const char* fn = "TestReadSysFileInt";
+  struct
+  {
+    /* input (file contents), e.g. "5" */
+    const char* input;
+    /* expected return value, if false, then the output is not checked */
+    bool ret;
+    /* expected result */
+    int output;
+  } tests[] = {
+    {"0", true, 0},
+    {"00", true, 0},
+    {"1", true, 1},
+    {"5", true, 5},
+    {"55", true, 55},
+
+    {" 123", true, 123},
+    {"123 ", true, 123},
+    {" 123 ", true, 123},
+    {"123\n", true, 123},
+
+    {"", false, 0},
+    {" ", false, 0},
+    {"a", false, 0},
+
+    {"-1", true, -1},
+    {" -456 ", true, -456},
+    {" -78.9 ", true, -78},
+  };
+
+  for (size_t i = 0; i < sizeof(tests) / sizeof(tests[0]); i++) {
+    ASSERT_TRUE(WriteFile(fn, tests[i].input, strlen(tests[i].input)));
+    /* Leave the file to exist if some of the assertions fail. */
+
+    bool ret;
+    int output = 424242;
+
+    ret = ReadSysFile(fn, &output);
+
+    ASSERT_EQ(tests[i].ret, ret);
+
+    if (ret) {
+      ASSERT_EQ(tests[i].output, output);
+    }
+  }
+
+  unlink(fn);
+}
+
+TEST(ReadSysFile, Bool) {
+  static const char* fn = "TestReadSysFileBool";
+  struct
+  {
+    /* input (file contents), e.g. "1" */
+    const char* input;
+    /* expected return value */
+    bool ret;
+    /* expected result */
+    bool output;
+  } tests[] = {
+    {"0", true, false},
+    {"00", true, false},
+    {"1", true, true},
+    {"5", true, true},
+    {"23", true, true},
+    {"-1", true, true},
+
+    {"", false, true /* unused */},
+  };
+
+  for (size_t i = 0; i < sizeof(tests) / sizeof(tests[0]); i++) {
+    ASSERT_TRUE(WriteFile(fn, tests[i].input, strlen(tests[i].input)));
+    /* Leave the file to exist if some of the assertions fail. */
+
+    bool ret;
+    bool output;
+
+    ret = ReadSysFile(fn, &output);
+
+    ASSERT_EQ(tests[i].ret, ret);
+
+    if (ret) {
+      ASSERT_EQ(tests[i].output, output);
+    }
+  }
+
+  unlink(fn);
+}
+
+#endif /* ReadSysFile_PRESENT */
+
+} // namespace mozilla