statx: fix compile errors with glibc<2.28

glibc 2.28 has shipped with a wrapper for the statx() system call. Currently the build is broken against it, because sys/stat.h suddenly declares all the same types that lapi/stat.h does. Fix it by taking the sys/stat.h ones if glibc>=2.28.

include/lapi/stat.h:26:8: error: redefinition of ‘struct statx_timestamp’ include/lapi/stat.h:73:8: error: redefinition of ‘struct statx’

---
 include/lapi/stat.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

index 979e42d..7ba8618 100644
@@ -20,7 +20,7 @@
  *
  * __reserved is held in case we need a yet finer resolution.
  */
-#if defined(HAVE_STRUCT_STATX_TIMESTAMP)
+#if defined(__GLIBC_PREREQ) && __GLIBC_PREREQ(2, 28)
 #include <sys/stat.h>
 #else
 struct statx_timestamp {

@@ -66,7 +66,7 @@ struct statx_timestamp {
  * will have values installed for compatibility purposes so that stat() and
  * co. can be emulated in userspace.
  */
-#if defined(HAVE_STRUCT_STATX)
+#if defined(__GLIBC_PREREQ) && __GLIBC_PREREQ(2, 28)
 #include <sys/stat.h>
 #else
 struct statx {

2.9.5

Hi!

What's wrong with the configure checks we do have?

See m4/ltp-statx.m4:

AC_CHECK_TYPES([struct statx],,,[[#include <sys/stat.h>]]) AC_CHECK_TYPES([struct statx_timestamp],,,[[#include <sys/stat.h>]])

That should check exactly if these structures are defined and export the HAVE_STRUCT_* macros?

Cyril Hrubis
[email protected]

Confusing...

It does not works for me. I checked the LTP "include/config.h" file after performing ./configure,
the HAVE_STRUCT_* macros undefined.

# cat include/config.h |grep -i statx
/* Define to 1 if you have the `statx' function. */
#define HAVE_STATX 1
/* Define to 1 if the system has the type `struct statx'. */
/* #undef HAVE_STRUCT_STATX */
/* Define to 1 if the system has the type `struct statx_timestamp'. */
/* #undef HAVE_STRUCT_STATX_TIMESTAMP */
And I also confirmed the struct statx has been defined in "bits/statx.h"
which was included by "sys/stat.h" on my platform(glibc>=2.28).

# grep "struct statx" /usr/include/bits/statx.h
struct statx_timestamp
struct statx
  struct statx_timestamp stx_atime;
  struct statx_timestamp stx_btime;
  struct statx_timestamp stx_ctime;
  struct statx_timestamp stx_mtime;
           unsigned int __mask, struct statx *__restrict __buf)

Regards,
Li Wang
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.linux.it/pipermail/ltp/attachments/20180919/37a50c7f/attachment.html>

Hi!

Check the config.log somewhere there is a test program that failed the compilation that tests for the struct statx and struct statx_timestamp.

Cyril Hrubis
[email protected]

struct statx is only defined in sys/stat.h when _GNU_SOURCE is defined. The testcases do define _GNU_SOURCE, but not the m4 struct check.

---
 m4/ltp-statx.m4 | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

index 44303d3..5f79a94 100644
@@ -23,6 +23,11 @@ dnl
 AC_DEFUN([LTP_CHECK_STATX],[
 AC_CHECK_FUNCS(statx,,,[[#include <sys/stat.h>]])
 AC_CHECK_HEADER(linux/fs.h,,,)
-AC_CHECK_TYPES([struct statx],,,[[#include <sys/stat.h>]])
-AC_CHECK_TYPES([struct statx_timestamp],,,[[#include <sys/stat.h>]])
+AC_CHECK_TYPES([struct statx],,,[[
+	#define _GNU_SOURCE
+	#include <sys/stat.h>
+]])
+AC_CHECK_TYPES([struct statx_timestamp],,,[[
+	#define _GNU_SOURCE
+	#include <sys/stat.h>]])
 ])

2.17.1

Hi!

Ah, that is the missing bit, good catch, applied.

Cyril Hrubis
[email protected]