[glib] Clarify use of struct stat on Windows

[Tor Lillqvist <tml src gnome org>]

commit 021643cda4f9b13fd72e898165744e9aefb346cd
Author: Tor Lillqvist <tml iki fi>
Date:   Thu Feb 4 19:54:50 2010 +0200

    Clarify use of struct stat on Windows

 gio/glocalfile.c     |   23 ++++++++++++++---------
 gio/glocalfileinfo.c |   10 ++++++----
 glib/gstdio.c        |   24 +++++++++++++++++++-----
 glib/gstdio.h        |   37 +++++++++++++++++++++++++++++++++++++
 4 files changed, 76 insertions(+), 18 deletions(-)
---
diff --git a/gio/glocalfile.c b/gio/glocalfile.c
index d6eea13..a0b7cb3 100644
--- a/gio/glocalfile.c
+++ b/gio/glocalfile.c
@@ -107,6 +107,11 @@
 
 #include "gioalias.h"
 
+/* See gstdio.h */
+#ifndef G_OS_WIN32
+#define _g_stat_struct stat
+#endif
+
 static void g_local_file_file_iface_init (GFileIface *iface);
 
 static GFileAttributeInfoList *local_writable_attributes = NULL;
@@ -736,7 +741,7 @@ get_mount_info (GFileInfo             *fs_info,
 		const char            *path,
 		GFileAttributeMatcher *matcher)
 {
-  struct stat buf;
+  struct _g_stat_struct buf;
   gboolean got_info;
   gpointer info_as_ptr;
   guint mount_info;
@@ -1047,7 +1052,7 @@ g_local_file_find_enclosing_mount (GFile         *file,
                                    GError       **error)
 {
   GLocalFile *local = G_LOCAL_FILE (file);
-  struct stat buf;
+  struct _g_stat_struct buf;
   char *mountpoint;
   GMount *mount;
 
@@ -1093,7 +1098,7 @@ g_local_file_set_display_name (GFile         *file,
 {
   GLocalFile *local, *new_local;
   GFile *new_file, *parent;
-  struct stat statbuf;
+  struct _g_stat_struct statbuf;
   int errsv;
 
   parent = g_file_get_parent (file);
@@ -1504,7 +1509,7 @@ get_parent (const char *path,
             dev_t      *parent_dev)
 {
   char *parent, *tmp;
-  struct stat parent_stat;
+  struct _g_stat_struct parent_stat;
   int num_recursions;
   char *path_copy;
 
@@ -1713,12 +1718,12 @@ _g_local_file_has_trash_dir (const char *dirname, dev_t dir_dev)
   char *topdir, *globaldir, *trashdir, *tmpname;
   uid_t uid;
   char uid_str[32];
-  struct stat global_stat, trash_stat;
+  struct _g_stat_struct global_stat, trash_stat;
   gboolean res;
 
   if (g_once_init_enter (&home_dev_set))
     {
-      struct stat home_stat;
+      struct _g_stat_struct home_stat;
 
       g_stat (g_get_home_dir (), &home_stat);
       home_dev = home_stat.st_dev;
@@ -1780,7 +1785,7 @@ g_local_file_trash (GFile         *file,
 		    GError       **error)
 {
   GLocalFile *local = G_LOCAL_FILE (file);
-  struct stat file_stat, home_stat;
+  struct _g_stat_struct file_stat, home_stat;
   const char *homedir;
   char *trashdir, *topdir, *infodir, *filesdir;
   char *basename, *trashname, *trashfile, *infoname, *infofile;
@@ -1790,7 +1795,7 @@ g_local_file_trash (GFile         *file,
   gboolean is_homedir_trash;
   char delete_time[32];
   int fd;
-  struct stat trash_stat, global_stat;
+  struct _g_stat_struct trash_stat, global_stat;
   char *dirname, *globaldir;
   
   if (g_lstat (local->filename, &file_stat) != 0)
@@ -2188,7 +2193,7 @@ g_local_file_move (GFile                  *source,
 		   GError                **error)
 {
   GLocalFile *local_source, *local_destination;
-  struct stat statbuf;
+  struct _g_stat_struct statbuf;
   gboolean destination_exist, source_is_dir;
   char *backup_name;
   int res;
diff --git a/gio/glocalfileinfo.c b/gio/glocalfileinfo.c
index 0eb16db..a913e82 100644
--- a/gio/glocalfileinfo.c
+++ b/gio/glocalfileinfo.c
@@ -96,6 +96,11 @@
 
 #include "gioalias.h"
 
+/* See gstdio.h */
+#ifndef G_OS_WIN32
+#define _g_stat_struct stat
+#endif
+
 struct ThumbMD5Context {
 	guint32 buf[4];
 	guint32 bits[2];
@@ -788,10 +793,7 @@ _g_local_file_info_get_parent_info (const char            *dir,
 				    GFileAttributeMatcher *attribute_matcher,
 				    GLocalParentFileInfo  *parent_info)
 {
-  /* Use plain struct stat for now as long as we only look at the
-   * S_ISVTX bit which doesn't exist on Win32 anyway.
-   */
-  struct stat statbuf;
+  struct _g_stat_struct statbuf;
   int res;
 
   parent_info->extra_data = NULL;
diff --git a/glib/gstdio.c b/glib/gstdio.c
index 4971d9b..542a95e 100644
--- a/glib/gstdio.c
+++ b/glib/gstdio.c
@@ -51,6 +51,10 @@
 #error Please port this to your operating system
 #endif
 
+#if defined (_MSC_VER) && !defined(_WIN64)
+#undef _wstat
+#define _wstat _wstat32
+#endif
 
 /**
  * g_access:
@@ -442,8 +446,13 @@ g_chdir (const gchar *path)
  * Since: 2.6
  */
 int
-g_stat (const gchar *filename,
-	struct stat *buf)
+g_stat (const gchar           *filename,
+#ifdef G_OS_WIN32
+	struct _g_stat_struct *buf
+#else
+	struct stat           *buf
+#endif
+				  )
 {
 #ifdef G_OS_WIN32
   wchar_t *wfilename = g_utf8_to_utf16 (filename, -1, NULL, NULL, NULL);
@@ -464,7 +473,7 @@ g_stat (const gchar *filename,
       (!g_path_is_absolute (filename) || len > g_path_skip_root (filename) - filename))
     wfilename[len] = '\0';
 
-  retval = _wstat (wfilename, (struct _stat *) buf);
+  retval = _wstat (wfilename, buf);
   save_errno = errno;
 
   g_free (wfilename);
@@ -496,8 +505,13 @@ g_stat (const gchar *filename,
  * Since: 2.6
  */
 int
-g_lstat (const gchar *filename,
-	 struct stat *buf)
+g_lstat (const gchar           *filename,
+#ifdef G_OS_WIN32
+	 struct _g_stat_struct *buf
+#else
+	 struct stat           *buf
+#endif
+				   )
 {
 #ifdef HAVE_LSTAT
   /* This can't be Win32, so don't do the widechar dance. */
diff --git a/glib/gstdio.h b/glib/gstdio.h
index f71a4e3..b61bc6b 100644
--- a/glib/gstdio.h
+++ b/glib/gstdio.h
@@ -89,12 +89,49 @@ int g_mkdir     (const gchar *filename,
 
 int g_chdir     (const gchar *path);
 
+#ifdef G_OS_WIN32
+
+/* The _g_stat_struct struct tag is an internal implementation detail
+ * and not part of the public GLib API.
+ */
+
+#if defined (_MSC_VER) && !defined(_WIN64)
+
+/* Make it clear that we mean the struct with 32-bit st_size and
+ * 32-bit st_*time fields as that is how the 32-bit GLib DLL normally
+ * has been compiled. If you get a compiler warning when calling
+ * g_stat(), do take it seriously and make sure that the type of
+ * struct stat the code in GLib fills in matches the struct the type
+ * of struct stat you pass to g_stat(). To avoid hassle, just use the
+ * GIO API instead which doesn't use struct stat to get file
+ * attributes, .
+ */
+#define _g_stat_struct _stat32
+
+#else
+
+#define _g_stat_struct _stat
+
+#endif
+
+int g_stat      (const gchar           *filename,
+                 struct _g_stat_struct *buf);
+
+int g_lstat     (const gchar           *filename,
+                 struct _g_stat_struct *buf);
+
+#else
+
+/* No _g_stat_struct used on Unix */
+
 int g_stat      (const gchar *filename,
                  struct stat *buf);
 
 int g_lstat     (const gchar *filename,
                  struct stat *buf);
 
+#endif
+
 int g_unlink    (const gchar *filename);
 
 int g_remove    (const gchar *filename);