alpha: Remove anonymous union in struct stat [BZ #27042]

This is clever, but it confuses downstream detection in at least zstd
and GNOME's glib. zstd has preprocessor tests for the 'st_mtime' macro,
which is not provided by the path using the anonymous union; glib checks
for the presence of 'st_mtimensec' in struct stat but then tries to
access that field in struct statx (which might be a bug on its own).

Checked with a build for alpha-linux-gnu.

3 files changed, 66 insertions, 63 deletions

diff --git a/sysdeps/unix/sysv/linux/alpha/bits/struct_stat.h b/sysdeps/unix/sysv/linux/alpha/bits/struct_stat.h
index 1c9b424..d2aae9f 100644
--- a/sysdeps/unix/sysv/linux/alpha/bits/struct_stat.h
+++ b/sysdeps/unix/sysv/linux/alpha/bits/struct_stat.h
@@ -23,37 +23,6 @@
 #ifndef _BITS_STRUCT_STAT_H
 #define _BITS_STRUCT_STAT_H	1
 
-/* Nanosecond resolution timestamps are stored in a format equivalent to
-   'struct timespec'.  This is the type used whenever possible but the
-   Unix namespace rules do not allow the identifier 'timespec' to appear
-   in the <sys/stat.h> header.  Therefore we have to handle the use of
-   this header in strictly standard-compliant sources special.
-
-   Use neat tidy anonymous unions and structures when possible.  */
-
-#ifdef __USE_XOPEN2K8
-# if __GNUC_PREREQ(3,3)
-#  define __ST_TIME(X)				\
-	__extension__ union {			\
-	    struct timespec st_##X##tim;	\
-	    struct {				\
-		__time_t st_##X##time;		\
-		unsigned long st_##X##timensec;	\
-	    };					\
-	}
-# else
-#  define __ST_TIME(X) struct timespec st_##X##tim
-#  define st_atime st_atim.tv_sec
-#  define st_mtime st_mtim.tv_sec
-#  define st_ctime st_ctim.tv_sec
-# endif
-#else
-# define __ST_TIME(X)				\
-	__time_t st_##X##time;			\
-	unsigned long st_##X##timensec
-#endif
-
-
 struct stat
   {
     __dev_t st_dev;		/* Device.  */
@@ -77,9 +46,27 @@ struct stat
     __blksize_t st_blksize;	/* Optimal block size for I/O.  */
     __nlink_t st_nlink;		/* Link count.  */
     int __pad2;			/* Real padding.  */
-    __ST_TIME(a);		/* Time of last access.  */
-    __ST_TIME(m);		/* Time of last modification.  */
-    __ST_TIME(c);		/* Time of last status change.  */
+#ifdef __USE_XOPEN2K8
+    /* Nanosecond resolution timestamps are stored in a format
+       equivalent to 'struct timespec'.  This is the type used
+       whenever possible but the Unix namespace rules do not allow the
+       identifier 'timespec' to appear in the <sys/stat.h> header.
+       Therefore we have to handle the use of this header in strictly
+       standard-compliant sources special.  */
+    struct timespec st_atim;		/* Time of last access.  */
+    struct timespec st_mtim;		/* Time of last modification.  */
+    struct timespec st_ctim;		/* Time of last status change.  */
+# define st_atime st_atim.tv_sec	/* Backward compatibility.  */
+# define st_mtime st_mtim.tv_sec
+# define st_ctime st_ctim.tv_sec
+#else
+    __time_t st_atime;			/* Time of last access.  */
+    unsigned long int st_atimensec;	/* Nscecs of last access.  */
+    __time_t st_mtime;			/* Time of last modification.  */
+    unsigned long int st_mtimensec;	/* Nsecs of last modification.  */
+    __time_t st_ctime;			/* Time of last status change.  */
+    unsigned long int st_ctimensec;	/* Nsecs of last status change.  */
+#endif
     long __glibc_reserved[3];
   };
 
@@ -98,15 +85,31 @@ struct stat64
     __blksize_t st_blksize;	/* Optimal block size for I/O.  */
     __nlink_t st_nlink;		/* Link count.  */
     int __pad0;			/* Real padding.  */
-    __ST_TIME(a);		/* Time of last access.  */
-    __ST_TIME(m);		/* Time of last modification.  */
-    __ST_TIME(c);		/* Time of last status change.  */
+#ifdef __USE_XOPEN2K8
+    /* Nanosecond resolution timestamps are stored in a format
+       equivalent to 'struct timespec'.  This is the type used
+       whenever possible but the Unix namespace rules do not allow the
+       identifier 'timespec' to appear in the <sys/stat.h> header.
+       Therefore we have to handle the use of this header in strictly
+       standard-compliant sources special.  */
+    struct timespec st_atim;		/* Time of last access.  */
+    struct timespec st_mtim;		/* Time of last modification.  */
+    struct timespec st_ctim;		/* Time of last status change.  */
+# define st_atime st_atim.tv_sec	/* Backward compatibility.  */
+# define st_mtime st_mtim.tv_sec
+# define st_ctime st_ctim.tv_sec
+#else
+    __time_t st_atime;			/* Time of last access.  */
+    unsigned long int st_atimensec;	/* Nscecs of last access.  */
+    __time_t st_mtime;			/* Time of last modification.  */
+    unsigned long int st_mtimensec;	/* Nsecs of last modification.  */
+    __time_t st_ctime;			/* Time of last status change.  */
+    unsigned long int st_ctimensec;	/* Nsecs of last status change.  */
+#endif
     long __glibc_reserved[3];
   };
 #endif
 
-#undef __ST_TIME
-
 /* Tell code we have these members.  */
 #define	_STATBUF_ST_BLKSIZE
 #define _STATBUF_ST_RDEV
diff --git a/sysdeps/unix/sysv/linux/alpha/kernel_stat.h b/sysdeps/unix/sysv/linux/alpha/kernel_stat.h
index ff69045..a292920 100644
--- a/sysdeps/unix/sysv/linux/alpha/kernel_stat.h
+++ b/sysdeps/unix/sysv/linux/alpha/kernel_stat.h
@@ -9,9 +9,9 @@ struct kernel_stat
     unsigned int st_gid;
     unsigned int st_rdev;
     long int st_size;
-    unsigned long int st_atime;
-    unsigned long int st_mtime;
-    unsigned long int st_ctime;
+    unsigned long int st_atime_sec;
+    unsigned long int st_mtime_sec;
+    unsigned long int st_ctime_sec;
     unsigned int st_blksize;
     int st_blocks;
     unsigned int st_flags;
@@ -34,11 +34,11 @@ struct kernel_stat64
     unsigned int    st_nlink;
     unsigned int    __pad0;
 
-    unsigned long   st_atime;
+    unsigned long   st_atime_sec;
     unsigned long   st_atimensec;
-    unsigned long   st_mtime;
+    unsigned long   st_mtime_sec;
     unsigned long   st_mtimensec;
-    unsigned long   st_ctime;
+    unsigned long   st_ctime_sec;
     unsigned long   st_ctimensec;
     long            __glibc_reserved[3];
   };
@@ -54,9 +54,9 @@ struct glibc2_stat
     __gid_t st_gid;
     __dev_t st_rdev;
     __off_t st_size;
-    __time_t st_atime;
-    __time_t st_mtime;
-    __time_t st_ctime;
+    __time_t st_atime_sec;
+    __time_t st_mtime_sec;
+    __time_t st_ctime_sec;
     unsigned int st_blksize;
     int st_blocks;
     unsigned int st_flags;
@@ -74,9 +74,9 @@ struct glibc21_stat
     __gid_t st_gid;
     __dev_t st_rdev;
     __off_t st_size;
-    __time_t st_atime;
-    __time_t st_mtime;
-    __time_t st_ctime;
+    __time_t st_atime_sec;
+    __time_t st_mtime_sec;
+    __time_t st_ctime_sec;
     __blkcnt64_t st_blocks;
     __blksize_t st_blksize;
     unsigned int st_flags;
diff --git a/sysdeps/unix/sysv/linux/alpha/xstatconv.c b/sysdeps/unix/sysv/linux/alpha/xstatconv.c
index f716a10..43224a7 100644
--- a/sysdeps/unix/sysv/linux/alpha/xstatconv.c
+++ b/sysdeps/unix/sysv/linux/alpha/xstatconv.c
@@ -44,9 +44,9 @@ __xstat_conv (int vers, struct kernel_stat *kbuf, void *ubuf)
 	buf->st_gid = kbuf->st_gid;
 	buf->st_rdev = kbuf->st_rdev;
 	buf->st_size = kbuf->st_size;
-	buf->st_atime = kbuf->st_atime;
-	buf->st_mtime = kbuf->st_mtime;
-	buf->st_ctime = kbuf->st_ctime;
+	buf->st_atime_sec = kbuf->st_atime_sec;
+	buf->st_mtime_sec = kbuf->st_mtime_sec;
+	buf->st_ctime_sec = kbuf->st_ctime_sec;
 	buf->st_blksize = kbuf->st_blksize;
 	buf->st_blocks = kbuf->st_blocks;
 	buf->st_flags = kbuf->st_flags;
@@ -66,9 +66,9 @@ __xstat_conv (int vers, struct kernel_stat *kbuf, void *ubuf)
 	buf->st_gid = kbuf->st_gid;
 	buf->st_rdev = kbuf->st_rdev;
 	buf->st_size = kbuf->st_size;
-	buf->st_atime = kbuf->st_atime;
-	buf->st_mtime = kbuf->st_mtime;
-	buf->st_ctime = kbuf->st_ctime;
+	buf->st_atime_sec = kbuf->st_atime_sec;
+	buf->st_mtime_sec = kbuf->st_mtime_sec;
+	buf->st_ctime_sec = kbuf->st_ctime_sec;
 	buf->st_blocks = kbuf->st_blocks;
 	buf->st_blksize = kbuf->st_blksize;
 	buf->st_flags = kbuf->st_flags;
@@ -98,12 +98,12 @@ __xstat_conv (int vers, struct kernel_stat *kbuf, void *ubuf)
 	buf->st_nlink = kbuf->st_nlink;
 	buf->__pad0 = 0;
 
-	buf->st_atime = kbuf->st_atime;
-	buf->st_atimensec = 0;
-	buf->st_mtime = kbuf->st_mtime;
-	buf->st_mtimensec = 0;
-	buf->st_ctime = kbuf->st_ctime;
-	buf->st_ctimensec = 0;
+	buf->st_atim.tv_sec = kbuf->st_atime_sec;
+	buf->st_atim.tv_nsec = 0;
+	buf->st_mtim.tv_sec = kbuf->st_mtime_sec;
+	buf->st_mtim.tv_nsec = 0;
+	buf->st_ctim.tv_sec = kbuf->st_ctime_sec;
+	buf->st_ctim.tv_nsec = 0;
 
 	buf->__glibc_reserved[0] = 0;
 	buf->__glibc_reserved[1] = 0;