windows-stat-override: new module

[Bruno Haible]

This patch adds an override of 'struct stat' on native Windows platforms.

It's a separate module so that other modules can depend on it.
(Maybe a module is overkill and a .m4 file would be sufficient, but I
think it's easier to use this way.)


2017-05-13  Bruno Haible  <address@hidden>

        windows-stat-override: New module.
        * lib/sys_stat.in.h (stat) [GNULIB_OVERRIDES_STRUCT_STAT]: Provide own
        definition. Define GNULIB_defined_struct_stat.
        (fstat, fstatat, lstat, stat) [GNULIB_OVERRIDES_STRUCT_STAT]: Provoke
        link error if this symbol is used and the corresponding module is not
        in use.
        (_stat64, _stat32i64, _stati64, _stat32, _stat64i32): Don't redefine if
        GNULIB_OVERRIDES_STRUCT_STAT.
        * m4/sys_stat_h.m4 (gl_SYS_STAT_H_DEFAULTS): Initialize
        GNULIB_OVERRIDES_STRUCT_STAT.
        * modules/sys_stat (Makefile.am): Substitute
        GNULIB_OVERRIDES_STRUCT_STAT.
        * modules/windows-stat-override: New file.

diff --git a/lib/sys_stat.in.h b/lib/sys_stat.in.h
index 189598d..ef689b9 100644
--- a/lib/sys_stat.in.h
+++ b/lib/sys_stat.in.h
@@ -1,4 +1,4 @@
-/* Provide a more complete sys/stat header file.
+/* Provide a more complete sys/stat.h header file.
    Copyright (C) 2005-2017 Free Software Foundation, Inc.
 
    This program is free software; you can redistribute it and/or modify
@@ -72,6 +72,73 @@
 # define stat _stati64
 #endif
 
+/* Optionally, override 'struct stat' on native Windows.  */
+#if @GNULIB_OVERRIDES_STRUCT_STAT@
+
+# undef stat
+# if @GNULIB_STAT@
+#  define stat rpl_stat
+# else
+   /* Provoke a clear link error if stat() is used as a function and
+      module 'stat' is not in use.  */
+#  define stat stat_used_without_requesting_gnulib_module_stat
+# endif
+
+# if !GNULIB_defined_struct_stat
+struct stat
+{
+  dev_t st_dev;
+  ino_t st_ino;
+  mode_t st_mode;
+  nlink_t st_nlink;
+#  if 0
+  uid_t st_uid;
+#  else /* uid_t is not defined by default on native Windows.  */
+  short st_uid;
+#  endif
+#  if 0
+  gid_t st_gid;
+#  else /* gid_t is not defined by default on native Windows.  */
+  short st_gid;
+#  endif
+  dev_t st_rdev;
+  off_t st_size;
+#  if 0
+  blksize_t st_blksize;
+  blkcnt_t st_blocks;
+#  endif
+
+#  if 0
+  struct timespec st_atim;
+  struct timespec st_mtim;
+  struct timespec st_ctim;
+#  else
+  time_t st_atime;
+  time_t st_mtime;
+  time_t st_ctime;
+#  endif
+};
+#  if 0
+#   define st_atime st_atim.tv_sec
+#   define st_mtime st_mtim.tv_sec
+#   define st_ctime st_ctim.tv_sec
+#  endif
+#  define GNULIB_defined_struct_stat 1
+# endif
+
+/* Other possible values of st_mode.  */
+# if 0
+#  define _S_IFBLK  0x6000
+# endif
+# if 0
+#  define _S_IFLNK  0xA000
+# endif
+# if 0
+#  define _S_IFSOCK 0xC000
+# endif
+
+#endif
+
 #ifndef S_IFIFO
 # ifdef _S_IFIFO
 #  define S_IFIFO _S_IFIFO
@@ -345,6 +412,9 @@ _GL_CXXALIAS_RPL (fstat, int, (int fd, struct stat *buf));
 _GL_CXXALIAS_SYS (fstat, int, (int fd, struct stat *buf));
 # endif
 _GL_CXXALIASWARN (fstat);
+#elif @GNULIB_OVERRIDES_STRUCT_STAT@
+# undef fstat
+# define fstat fstat_used_without_requesting_gnulib_module_fstat
 #elif @WINDOWS_64_BIT_ST_SIZE@
 /* Above, we define stat to _stati64.  */
 # define fstat _fstati64
@@ -378,6 +448,9 @@ _GL_CXXALIAS_SYS (fstatat, int,
                   (int fd, char const *name, struct stat *st, int flags));
 # endif
 _GL_CXXALIASWARN (fstatat);
+#elif @GNULIB_OVERRIDES_STRUCT_STAT@
+# undef fstatat
+# define fstatat fstatat_used_without_requesting_gnulib_module_fstatat
 #elif defined GNULIB_POSIXCHECK
 # undef fstatat
 # if HAVE_RAW_DECL_FSTATAT
@@ -476,6 +549,9 @@ _GL_CXXALIAS_SYS (lstat, int, (const char *name, struct 
stat *buf));
 # if @HAVE_LSTAT@
 _GL_CXXALIASWARN (lstat);
 # endif
+#elif @GNULIB_OVERRIDES_STRUCT_STAT@
+# undef lstat
+# define lstat lstat_used_without_requesting_gnulib_module_lstat
 #elif defined GNULIB_POSIXCHECK
 # undef lstat
 # if HAVE_RAW_DECL_LSTAT
@@ -625,63 +701,69 @@ _GL_WARN_ON_USE (mknodat, "mknodat is not portable - "
 
 #if @GNULIB_STAT@
 # if @REPLACE_STAT@
-/* We can't use the object-like #define stat rpl_stat, because of
-   struct stat.  This means that rpl_stat will not be used if the user
-   does (stat)(a,b).  Oh well.  */
-#  if defined _AIX && defined stat && defined _LARGE_FILES
-    /* With _LARGE_FILES defined, AIX (only) defines stat to stat64,
-       so we have to replace stat64() instead of stat(). */
-#   undef stat64
-#   define stat64(name, st) rpl_stat (name, st)
-#  elif @WINDOWS_64_BIT_ST_SIZE@
-    /* Above, we define stat to _stati64.  */
-#   if defined __MINGW32__ && defined _stati64
-#    ifndef _USE_32BIT_TIME_T
-      /* The system headers define _stati64 to _stat64.  */
-#     undef _stat64
-#     define _stat64(name, st) rpl_stat (name, st)
+#  if address@hidden@
+    /* We can't use the object-like #define stat rpl_stat, because of
+       struct stat.  This means that rpl_stat will not be used if the user
+       does (stat)(a,b).  Oh well.  */
+#   if defined _AIX && defined stat && defined _LARGE_FILES
+     /* With _LARGE_FILES defined, AIX (only) defines stat to stat64,
+        so we have to replace stat64() instead of stat(). */
+#    undef stat64
+#    define stat64(name, st) rpl_stat (name, st)
+#   elif @WINDOWS_64_BIT_ST_SIZE@
+     /* Above, we define stat to _stati64.  */
+#    if defined __MINGW32__ && defined _stati64
+#     ifndef _USE_32BIT_TIME_T
+       /* The system headers define _stati64 to _stat64.  */
+#      undef _stat64
+#      define _stat64(name, st) rpl_stat (name, st)
+#     endif
+#    elif defined _MSC_VER && defined _stati64
+#     ifdef _USE_32BIT_TIME_T
+       /* The system headers define _stati64 to _stat32i64.  */
+#      undef _stat32i64
+#      define _stat32i64(name, st) rpl_stat (name, st)
+#     else
+       /* The system headers define _stati64 to _stat64.  */
+#      undef _stat64
+#      define _stat64(name, st) rpl_stat (name, st)
+#     endif
+#    else
+#     undef _stati64
+#     define _stati64(name, st) rpl_stat (name, st)
 #    endif
-#   elif defined _MSC_VER && defined _stati64
+#   elif defined __MINGW32__ && defined stat
 #    ifdef _USE_32BIT_TIME_T
-      /* The system headers define _stati64 to _stat32i64.  */
+      /* The system headers define stat to _stat32i64.  */
 #     undef _stat32i64
 #     define _stat32i64(name, st) rpl_stat (name, st)
 #    else
-      /* The system headers define _stati64 to _stat64.  */
+      /* The system headers define stat to _stat64.  */
 #     undef _stat64
 #     define _stat64(name, st) rpl_stat (name, st)
 #    endif
-#   else
-#    undef _stati64
-#    define _stati64(name, st) rpl_stat (name, st)
-#   endif
-#  elif defined __MINGW32__ && defined stat
-#   ifdef _USE_32BIT_TIME_T
-     /* The system headers define stat to _stat32i64.  */
-#    undef _stat32i64
-#    define _stat32i64(name, st) rpl_stat (name, st)
-#   else
-     /* The system headers define stat to _stat64.  */
-#    undef _stat64
-#    define _stat64(name, st) rpl_stat (name, st)
-#   endif
-#  elif defined _MSC_VER && defined stat
-#   ifdef _USE_32BIT_TIME_T
-     /* The system headers define stat to _stat32.  */
-#    undef _stat32
-#    define _stat32(name, st) rpl_stat (name, st)
-#   else
-     /* The system headers define stat to _stat64i32.  */
-#    undef _stat64i32
-#    define _stat64i32(name, st) rpl_stat (name, st)
-#   endif
-#  else /* !(_AIX ||__MINGW32__ ||  _MSC_VER) */
-#   undef stat
-#   define stat(name, st) rpl_stat (name, st)
-#  endif /* !_LARGE_FILES */
+#   elif defined _MSC_VER && defined stat
+#    ifdef _USE_32BIT_TIME_T
+      /* The system headers define stat to _stat32.  */
+#     undef _stat32
+#     define _stat32(name, st) rpl_stat (name, st)
+#    else
+      /* The system headers define stat to _stat64i32.  */
+#     undef _stat64i32
+#     define _stat64i32(name, st) rpl_stat (name, st)
+#    endif
+#   else /* !(_AIX || __MINGW32__ || _MSC_VER) */
+#    undef stat
+#    define stat(name, st) rpl_stat (name, st)
+#   endif /* !_LARGE_FILES */
+#  endif /* address@hidden@ */
 _GL_EXTERN_C int stat (const char *name, struct stat *buf)
                       _GL_ARG_NONNULL ((1, 2));
 # endif
+#elif @GNULIB_OVERRIDES_STRUCT_STAT@
+/* see above:
+  #define stat stat_used_without_requesting_gnulib_module_stat
+ */
 #elif defined GNULIB_POSIXCHECK
 # undef stat
 # if HAVE_RAW_DECL_STAT
diff --git a/m4/sys_stat_h.m4 b/m4/sys_stat_h.m4
index 1e34ac4..f0f443e 100644
--- a/m4/sys_stat_h.m4
+++ b/m4/sys_stat_h.m4
@@ -1,4 +1,4 @@
-# sys_stat_h.m4 serial 28   -*- Autoconf -*-
+# sys_stat_h.m4 serial 29   -*- Autoconf -*-
 dnl Copyright (C) 2006-2017 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -72,6 +72,7 @@ AC_DEFUN([gl_SYS_STAT_H_DEFAULTS],
   GNULIB_MKNODAT=0;     AC_SUBST([GNULIB_MKNODAT])
   GNULIB_STAT=0;        AC_SUBST([GNULIB_STAT])
   GNULIB_UTIMENSAT=0;   AC_SUBST([GNULIB_UTIMENSAT])
+  GNULIB_OVERRIDES_STRUCT_STAT=0; AC_SUBST([GNULIB_OVERRIDES_STRUCT_STAT])
   dnl Assume proper GNU behavior unless another module says otherwise.
   HAVE_FCHMODAT=1;      AC_SUBST([HAVE_FCHMODAT])
   HAVE_FSTATAT=1;       AC_SUBST([HAVE_FSTATAT])
diff --git a/modules/sys_stat b/modules/sys_stat
index f8d8633..2e0aa75 100644
--- a/modules/sys_stat
+++ b/modules/sys_stat
@@ -46,6 +46,7 @@ sys/stat.h: sys_stat.in.h $(top_builddir)/config.status 
$(CXXDEFS_H) $(ARG_NONNU
              -e 's/@''GNULIB_MKNODAT''@/$(GNULIB_MKNODAT)/g' \
              -e 's/@''GNULIB_STAT''@/$(GNULIB_STAT)/g' \
              -e 's/@''GNULIB_UTIMENSAT''@/$(GNULIB_UTIMENSAT)/g' \
+             -e 
's/@''GNULIB_OVERRIDES_STRUCT_STAT''@/$(GNULIB_OVERRIDES_STRUCT_STAT)/g' \
              -e 's|@''HAVE_FCHMODAT''@|$(HAVE_FCHMODAT)|g' \
              -e 's|@''HAVE_FSTATAT''@|$(HAVE_FSTATAT)|g' \
              -e 's|@''HAVE_FUTIMENS''@|$(HAVE_FUTIMENS)|g' \
diff --git a/modules/windows-stat-override b/modules/windows-stat-override
new file mode 100644
index 0000000..027fa92
--- /dev/null
+++ b/modules/windows-stat-override
@@ -0,0 +1,30 @@
+Description:
+On native Windows platforms, override 'struct stat'.
+
+Comment:
+This module should not be used as a dependency from a test module,
+otherwise when this module occurs as a tests-related module, it will
+have side effects on the compilation of the main modules in lib/.
+
+Files:
+
+Depends-on:
+sys_stat
+
+configure.ac:
+AC_REQUIRE([gl_SYS_STAT_H_DEFAULTS])
+AC_REQUIRE([AC_CANONICAL_HOST])
+case "$host_os" in
+  mingw*) GNULIB_OVERRIDES_STRUCT_STAT=1 ;;
+esac
+
+Makefile.am:
+
+Include:
+<sys/stat.h>
+
+License:
+LGPLv2+
+
+Maintainer:
+Bruno Haible