Add fxstat check to glibc_syscall_wrappers test.

tests/glibc_syscall_wrappers/test_fstat.c

+/*
+ * Copyright 2010 The Native Client 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 <assert.h>
+#include <errno.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <sys/stat.h>
+
+int main(int argc, char** argv) {
+  struct stat st;
+  FILE* file;
+  int fd;
+  if (2 != argc) {
+    printf("Usage: sel_ldr test_fstat.nexe test_stat_data\n");
+    return 1;
+  }
+  st.st_size = 0;
+  printf(
+      "%d+%d %d+%d %d+%d %d+%d %d+%d %d+%d %d+%d %d+%d %d+%d %d+%d %d+%d %d\n",

[eaeltsin, 2011/01/19 12:54:28]

Probably make the output more verbose? Like

  st_dev offset: %d, size: %d
  st_ino offset: %d, size: %d
  ...

Probably print struct stat sizeof as well?

[halyavin, 2011/01/19 14:19:25]

Done. I already print size of stat structure.

+      offsetof(struct stat,st_dev),sizeof(st.st_dev),
+      offsetof(struct stat,st_ino),sizeof(st.st_ino),
+      offsetof(struct stat,st_mode),sizeof(st.st_mode),
+      offsetof(struct stat,st_nlink),sizeof(st.st_nlink),
+      offsetof(struct stat,st_uid),sizeof(st.st_uid),
+      offsetof(struct stat,st_gid),sizeof(st.st_gid),
+      offsetof(struct stat,st_rdev),sizeof(st.st_rdev),
+      offsetof(struct stat,st_size),sizeof(st.st_size),
+      offsetof(struct stat,st_blksize),sizeof(st.st_blksize),
+      offsetof(struct stat,st_blocks),sizeof(st.st_blocks),
+      offsetof(struct stat,st_atim),sizeof(st.st_atim),
+      sizeof(st));
+  file = fopen( argv[1], "r");
+  assert (NULL != file);
+  fd = fileno(file);
+  errno = 0;
+  assert (0 ==  fstat(fd, &st));

[eaeltsin, 2011/01/19 12:54:28]

I doubt having meaningful side effects inside assert is a good practice. There
is nothing that prevents compiling this with NDEBUG set to true (yes, I see that
other tests use this practice, this is not an excuse).

Why not
  if (!fstat(fd, &st))
    abort();

Or even better
  if (!fstat(fd, &st))
    return -1;  /* Use different negative return values for different failures
*/

[halyavin, 2011/01/19 14:19:25]

Done. I use positive return values though.

+  printf("%d\n",(int)st.st_size);
+  assert (0 == errno);
+  assert (0 == fclose(file));
+  errno = 0;
+  assert (-1 == fstat(-1, &st));
+  assert (EBADF == errno);
+  return 0;
+}