* lisp.h (toplevel): Add comment about using Lisp_Save_Value

objects, related functions and macros.
(make_save_value): Adjust prototype.
(make_save_pointer): New prototype.
(SAFE_NALLOCA): Fix indentation.  Use make_save_pointer.
(SAFE_ALLOCA_LISP): Adjust make_save_value usage.
* alloc.c (format_save_value): Rename to make_save_value.
(make_save_pointer): New function.
(record_xmalloc): Use make_save_pointer.
* dired.c, editfns.c, fileio.c, font.c, gtkutil.c, lread.c:
* nsmenu.m, nsterm.m, xfns.c, xmenu.c, xselect.c, keymap.c:
Change users of make_save_value to make_save_pointer.
Likewise for format_save_value and make_save_value.

16 files changed, 101 insertions, 38 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 316995bf20b..c85e0a789ea 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,5 +1,21 @@
 2013-01-17  Dmitry Antipov  <dmantipov@yandex.ru>
 
+        * lisp.h (toplevel): Add comment about using Lisp_Save_Value
+        objects, related functions and macros.
+        (make_save_value): Adjust prototype.
+        (make_save_pointer): New prototype.
+        (SAFE_NALLOCA): Fix indentation.  Use make_save_pointer.
+        (SAFE_ALLOCA_LISP): Adjust make_save_value usage.
+        * alloc.c (format_save_value): Rename to make_save_value.
+        (make_save_pointer): New function.
+        (record_xmalloc): Use make_save_pointer.
+        * dired.c, editfns.c, fileio.c, font.c, gtkutil.c, lread.c:
+        * nsmenu.m, nsterm.m, xfns.c, xmenu.c, xselect.c, keymap.c:
+        Change users of make_save_value to make_save_pointer.
+        Likewise for format_save_value and make_save_value.
+
+2013-01-17  Dmitry Antipov  <dmantipov@yandex.ru>
+
         * buffer.h (NARROWED, BUF_NARROWED): Drop unused macros.
         (DECODE_POSITION, BUFFER_CHECK_INDIRECTION): Fix indentation.
         * buffer.c (toplevel, syms_of_buffer): Drop old commented-out
diff --git a/src/alloc.c b/src/alloc.c
index 7275a01bb73..a2e7282bb60 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -845,7 +845,7 @@ void *
 record_xmalloc (size_t size)
 {
   void *p = xmalloc (size);
-  record_unwind_protect (safe_alloca_unwind, make_save_value (p, 0));
+  record_unwind_protect (safe_alloca_unwind, make_save_pointer (p));
   return p;
 }
 
@@ -3356,7 +3356,7 @@ free_misc (Lisp_Object misc)
    and `o' for Lisp_Object.  Up to 4 objects can be specified.  */
 
 Lisp_Object
-format_save_value (const char *fmt, ...)
+make_save_value (const char *fmt, ...)
 {
   va_list ap;
   int len = strlen (fmt);
@@ -3404,15 +3404,19 @@ format_save_value (const char *fmt, ...)
   return val;
 }
 
-/* Return a Lisp_Save_Value object containing POINTER and INTEGER.
-   Most code should use this to package C integers and pointers
-   to call record_unwind_protect.  The unwind function can get the
-   C values back using XSAVE_POINTER and XSAVE_INTEGER.  */
+/* The most common task it to save just one C pointer.  */
 
 Lisp_Object
-make_save_value (void *pointer, ptrdiff_t integer)
+make_save_pointer (void *pointer)
 {
-  return format_save_value ("pi", pointer, integer);
+  Lisp_Object val = allocate_misc (Lisp_Misc_Save_Value);
+  struct Lisp_Save_Value *p = XSAVE_VALUE (val);
+
+  p->area = 0;
+  p->type0 = SAVE_POINTER;
+  p->data[0].pointer = pointer;
+  p->type1 = p->type2 = p->type3 = SAVE_UNUSED;
+  return val;
 }
 
 /* Free a Lisp_Save_Value object.  Do not use this function
diff --git a/src/dired.c b/src/dired.c
index 3dca9d24f67..a4c8621e9c0 100644
--- a/src/dired.c
+++ b/src/dired.c
@@ -152,7 +152,7 @@ directory_files_internal (Lisp_Object directory, Lisp_Object full,
      file-attributes on filenames, both of which can throw, so we must
      do a proper unwind-protect.  */
   record_unwind_protect (directory_files_internal_unwind,
-                         make_save_value (d, 0));
+                         make_save_pointer (d));
 
 #ifdef WINDOWSNT
   if (attrs)
@@ -465,7 +465,7 @@ file_name_completion (Lisp_Object file, Lisp_Object dirname, bool all_flag,
     report_file_error ("Opening directory", Fcons (dirname, Qnil));
 
   record_unwind_protect (directory_files_internal_unwind,
-                         make_save_value (d, 0));
+                         make_save_pointer (d));
 
   /* Loop reading blocks */
   /* (att3b compiler bug requires do a null comparison this way) */
diff --git a/src/editfns.c b/src/editfns.c
index 8910b66e4d3..197950517b7 100644
--- a/src/editfns.c
+++ b/src/editfns.c
@@ -833,7 +833,7 @@ This function does not move point.  */)
 Lisp_Object
 save_excursion_save (void)
 {
-  return format_save_value
+  return make_save_value
     ("oooo",
      Fpoint_marker (),
      /* Do not copy the mark if it points to nowhere.  */
@@ -4249,7 +4249,7 @@ usage: (format STRING &rest OBJECTS)  */)
           {
             buf = xmalloc (bufsize);
             sa_must_free = 1;
-            buf_save_value = make_save_value (buf, 0);
+            buf_save_value = make_save_pointer (buf);
             record_unwind_protect (safe_alloca_unwind, buf_save_value);
             memcpy (buf, initial_buffer, used);
           }
diff --git a/src/fileio.c b/src/fileio.c
index 87d945c1e5e..8d711e8e6bf 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -4249,7 +4249,7 @@ by calling `format-decode', which see.  */)
                to be signaled after decoding the text we read.  */
             nbytes = internal_condition_case_1
               (read_non_regular,
-               format_save_value ("iii", (ptrdiff_t) fd, inserted, trytry),
+               make_save_value ("iii", (ptrdiff_t) fd, inserted, trytry),
                Qerror, read_non_regular_quit);
 
             if (NILP (nbytes))
@@ -5608,7 +5608,7 @@ A non-nil CURRENT-ONLY argument means save only current buffer.  */)
     }
 
   record_unwind_protect (do_auto_save_unwind,
-                         make_save_value (stream, 0));
+                         make_save_pointer (stream));
   record_unwind_protect (do_auto_save_unwind_1,
                          make_number (minibuffer_auto_raise));
   minibuffer_auto_raise = 0;
diff --git a/src/font.c b/src/font.c
index 89931f6ec76..18caf751643 100644
--- a/src/font.c
+++ b/src/font.c
@@ -1861,7 +1861,7 @@ otf_open (Lisp_Object file)
   else
     {
       otf = STRINGP (file) ? OTF_open (SSDATA (file)) : NULL;
-      val = make_save_value (otf, 0);
+      val = make_save_pointer (otf);
       otf_list = Fcons (Fcons (file, val), otf_list);
     }
   return otf;
diff --git a/src/ftfont.c b/src/ftfont.c
index 5bf91832c7c..03e40bf2e46 100644
--- a/src/ftfont.c
+++ b/src/ftfont.c
@@ -393,7 +393,7 @@ ftfont_lookup_cache (Lisp_Object key, enum ftfont_cache_for cache_for)
       cache_data = xmalloc (sizeof *cache_data);
       cache_data->ft_face = NULL;
       cache_data->fc_charset = NULL;
-      val = make_save_value (cache_data, 0);
+      val = make_save_value ("pi", cache_data, 0);
       cache = Fcons (Qnil, val);
       Fputhash (key, cache, ft_face_cache);
     }
diff --git a/src/gtkutil.c b/src/gtkutil.c
index f045deacd33..d5bc159c063 100644
--- a/src/gtkutil.c
+++ b/src/gtkutil.c
@@ -1716,7 +1716,7 @@ xg_dialog_run (FRAME_PTR f, GtkWidget *w)
   g_signal_connect (G_OBJECT (w), "delete-event", G_CALLBACK (gtk_true), NULL);
   gtk_widget_show (w);
 
-  record_unwind_protect (pop_down_dialog, make_save_value (&dd, 0));
+  record_unwind_protect (pop_down_dialog, make_save_pointer (&dd));
 
   (void) xg_maybe_add_timer (&dd);
   g_main_loop_run (dd.loop);
diff --git a/src/keymap.c b/src/keymap.c
index a9266120e86..1e201e06dc3 100644
--- a/src/keymap.c
+++ b/src/keymap.c
@@ -610,7 +610,7 @@ map_keymap_internal (Lisp_Object map,
         }
       else if (CHAR_TABLE_P (binding))
         map_char_table (map_keymap_char_table_item, Qnil, binding,
-                        format_save_value ("ppo", fun, data, args));
+                        make_save_value ("ppo", fun, data, args));
     }
   UNGCPRO;
   return tail;
diff --git a/src/lisp.h b/src/lisp.h
index 40e4821bc10..5c81bc5dd8a 100644
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -1388,7 +1388,50 @@ enum
     SAVE_OBJECT
   };
 
-/* Special object used to hold a different values for later use.  */
+/* Special object used to hold a different values for later use.
+
+   This is mostly used to package C integers and pointers to call
+   record_unwind_protect.  Typical task is to pass just one C pointer
+   to unwind function.  You should pack pointer with make_save_pointer
+   and then get it back with XSAVE_POINTER, e.g.:
+
+   ...
+     struct my_data *md = get_my_data ();
+     record_unwind_protect (my_unwind, make_save_pointer (md));
+   ...
+
+   Lisp_Object my_unwind (Lisp_Object arg)
+   {
+     struct my_data *md = XSAVE_POINTER (arg, 0);
+     ...
+   }
+
+   If yon need to pass more than just one C pointer, you should
+   use make_save_value.  This function allows you to pack up to
+   4 integers, pointers or Lisp_Objects and conveniently get them
+   back with XSAVE_POINTER, XSAVE_INTEGER and XSAVE_OBJECT macros:
+
+   ...
+     struct my_data *md = get_my_data ();
+     ptrdiff_t my_offset = get_my_offset ();
+     Lisp_Object my_object = get_my_object ();
+     record_unwind_protect
+       (my_unwind, make_save_value ("pio", md, my_offset, my_object));
+   ...
+
+   Lisp_Object my_unwind (Lisp_Object arg)
+   {
+     struct my_data *md = XSAVE_POINTER (arg, 0);
+     ptrdiff_t my_offset = XSAVE_INTEGER (arg, 1);
+     Lisp_Object my_object = XSAVE_OBJECT (arg, 2);
+     ...
+   }
+
+   If ENABLE_CHECKING is in effect, XSAVE_xxx macros do type checking of the
+   saved objects and raise eassert if type of the saved object doesn't match
+   the type which is extracted.  In the example above, XSAVE_INTEGER (arg, 2)
+   or XSAVE_OBJECT (arg, 1) are wrong because integer was saved in slot 1 and
+   Lisp_Object was saved in slot 2 of ARG.  */
 
 struct Lisp_Save_Value
   {
@@ -3018,8 +3061,8 @@ extern bool abort_on_gc;
 extern Lisp_Object make_float (double);
 extern void display_malloc_warning (void);
 extern ptrdiff_t inhibit_garbage_collection (void);
-extern Lisp_Object format_save_value (const char *, ...);
-extern Lisp_Object make_save_value (void *, ptrdiff_t);
+extern Lisp_Object make_save_value (const char *, ...);
+extern Lisp_Object make_save_pointer (void *);
 extern Lisp_Object build_overlay (Lisp_Object, Lisp_Object, Lisp_Object);
 extern void free_marker (Lisp_Object);
 extern void free_cons (struct Lisp_Cons *);
@@ -3701,16 +3744,16 @@ extern void *record_xmalloc (size_t);
    NITEMS items, each of the same type as *BUF.  MULTIPLIER must
    positive.  The code is tuned for MULTIPLIER being a constant.  */
 
-#define SAFE_NALLOCA(buf, multiplier, nitems)                   \
-  do {                                                          \
-    if ((nitems) <= MAX_ALLOCA / sizeof *(buf) / (multiplier))  \
-      (buf) = alloca (sizeof *(buf) * (multiplier) * (nitems)); \
-    else                                                        \
+#define SAFE_NALLOCA(buf, multiplier, nitems)                    \
+  do {                                                           \
+    if ((nitems) <= MAX_ALLOCA / sizeof *(buf) / (multiplier))   \
+      (buf) = alloca (sizeof *(buf) * (multiplier) * (nitems));  \
+    else                                                         \
       {                                                          \
         (buf) = xnmalloc (nitems, sizeof *(buf) * (multiplier)); \
         sa_must_free = 1;                                        \
         record_unwind_protect (safe_alloca_unwind,               \
-                               make_save_value (buf, 0));        \
+                               make_save_pointer (buf));         \
       }                                                          \
   } while (0)
 
@@ -3735,7 +3778,7 @@ extern void *record_xmalloc (size_t);
       {                                                        \
         Lisp_Object arg_;                                      \
         buf = xmalloc ((nelt) * word_size);                    \
-        arg_ = make_save_value (buf, nelt);                    \
+        arg_ = make_save_value ("pi", buf, nelt);              \
         XSAVE_VALUE (arg_)->area = 1;                          \
         sa_must_free = 1;                                      \
         record_unwind_protect (safe_alloca_unwind, arg_);      \
diff --git a/src/lread.c b/src/lread.c
index a01cf099b49..09eccb0fb30 100644
--- a/src/lread.c
+++ b/src/lread.c
@@ -1298,7 +1298,7 @@ Return t if the file exists and loads successfully.  */)
         message_with_string ("Loading %s...", file, 1);
     }
 
-  record_unwind_protect (load_unwind, make_save_value (stream, 0));
+  record_unwind_protect (load_unwind, make_save_pointer (stream));
   record_unwind_protect (load_descriptor_unwind, load_descriptor_list);
   specbind (Qload_file_name, found);
   specbind (Qinhibit_file_name_operation, Qnil);
diff --git a/src/nsmenu.m b/src/nsmenu.m
index b0369e76a27..6899e3575f5 100644
--- a/src/nsmenu.m
+++ b/src/nsmenu.m
@@ -1440,7 +1440,7 @@ ns_popup_dialog (Lisp_Object position, Lisp_Object contents, Lisp_Object header)
     unwind_data->pool = pool;
     unwind_data->dialog = dialog;
 
-    record_unwind_protect (pop_down_menu, make_save_value (unwind_data, 0));
+    record_unwind_protect (pop_down_menu, make_save_pointer (unwind_data));
     popup_activated_flag = 1;
     tem = [dialog runDialogAt: p];
     unbind_to (specpdl_count, Qnil);  /* calls pop_down_menu */
diff --git a/src/nsterm.m b/src/nsterm.m
index 48efac3f70b..d346f05624b 100644
--- a/src/nsterm.m
+++ b/src/nsterm.m
@@ -3677,7 +3677,7 @@ ns_set_vertical_scroll_bar (struct window *window,
         }
 
       bar = [[EmacsScroller alloc] initFrame: r window: win];
-      wset_vertical_scroll_bar (window, make_save_value (bar, 0));
+      wset_vertical_scroll_bar (window, make_save_pointer (bar));
     }
   else
     {
diff --git a/src/xfns.c b/src/xfns.c
index 65148d1c9e1..f01983fea4d 100644
--- a/src/xfns.c
+++ b/src/xfns.c
@@ -5416,7 +5416,7 @@ Otherwise, if ONLY-DIR-P is non-nil, the user can only select directories.  */)
       XmStringFree (default_xmstring);
     }
 
-  record_unwind_protect (clean_up_file_dialog, make_save_value (dialog, 0));
+  record_unwind_protect (clean_up_file_dialog, make_save_pointer (dialog));
 
   /* Process events until the user presses Cancel or OK.  */
   x_menu_set_in_use (1);
diff --git a/src/xmenu.c b/src/xmenu.c
index 7f6914d26ac..958cd220393 100644
--- a/src/xmenu.c
+++ b/src/xmenu.c
@@ -1477,7 +1477,7 @@ create_and_show_popup_menu (FRAME_PTR f, widget_value *first_wv, int x, int y,
   gtk_menu_popup (GTK_MENU (menu), 0, 0, pos_func, &popup_x_y, i,
                   timestamp ? timestamp : gtk_get_current_event_time ());
 
-  record_unwind_protect (pop_down_menu, make_save_value (menu, 0));
+  record_unwind_protect (pop_down_menu, make_save_pointer (menu));
 
   if (gtk_widget_get_mapped (menu))
     {
@@ -1826,7 +1826,7 @@ xmenu_show (FRAME_PTR f, int x, int y, bool for_click, bool keymaps,
   /* Make sure to free the widget_value objects we used to specify the
      contents even with longjmp.  */
   record_unwind_protect (cleanup_widget_value_tree,
-                         make_save_value (first_wv, 0));
+                         make_save_pointer (first_wv));
 
   /* Actually create and show the menu until popped down.  */
   create_and_show_popup_menu (f, first_wv, x, y, for_click, timestamp);
@@ -1925,7 +1925,7 @@ create_and_show_dialog (FRAME_PTR f, widget_value *first_wv)
   if (menu)
     {
       ptrdiff_t specpdl_count = SPECPDL_INDEX ();
-      record_unwind_protect (pop_down_menu, make_save_value (menu, 0));
+      record_unwind_protect (pop_down_menu, make_save_pointer (menu));
 
       /* Display the menu.  */
       gtk_widget_show_all (menu);
@@ -2136,7 +2136,7 @@ xdialog_show (FRAME_PTR f,
   /* Make sure to free the widget_value objects we used to specify the
      contents even with longjmp.  */
   record_unwind_protect (cleanup_widget_value_tree,
-                         make_save_value (first_wv, 0));
+                         make_save_pointer (first_wv));
 
   /* Actually create and show the dialog.  */
   create_and_show_dialog (f, first_wv);
@@ -2479,7 +2479,7 @@ xmenu_show (FRAME_PTR f, int x, int y, bool for_click, bool keymaps,
 #endif
 
   record_unwind_protect (pop_down_menu,
-                         format_save_value ("pp", f, menu));
+                         make_save_value ("pp", f, menu));
 
   /* Help display under X won't work because XMenuActivate contains
      a loop that doesn't give Emacs a chance to process it.  */
diff --git a/src/xselect.c b/src/xselect.c
index b7cdf70ff77..37d2c753c5e 100644
--- a/src/xselect.c
+++ b/src/xselect.c
@@ -1141,7 +1141,7 @@ wait_for_property_change (struct prop_location *location)
 
   /* Make sure to do unexpect_property_change if we quit or err.  */
   record_unwind_protect (wait_for_property_change_unwind,
-                         make_save_value (location, 0));
+                         make_save_pointer (location));
 
   XSETCAR (property_change_reply, Qnil);
   property_change_reply_object = location;