Omit buffer_slot_type_mismatch and use generic predicates to enforce

the type of per-buffer values where appropriate.
* src/lisp.h (struct Lisp_Buffer_Objfwd): Rename slottype member to
predicate, which is how it's really used now.  Adjust comment.
* src/buffer.h (buffer_slot_type_mismatch): Remove prototype.
* src/buffer.c (buffer_slot_type_mismatch): Remove.
(DEFVAR_PER_BUFFER, defvar_per_buffer): Rename type argument to
predicate.  Adjust comment.
(syms_of_buffer): Use Qsymbolp for major-mode.  Use Qintegerp for
fill-column, left-margin, tab-width, buffer-saved-size,
left-margin-width, right-margin-width, left-fringe-width,
right-fringe-width, scroll-bar-width and buffer-display-count.
Use Qstringp for default-directory, buffer-file-name,
buffer-file-truename and buffer-auto-save-file-name.  Use Qfloatp for
scroll-up-aggressively and scroll-down-aggressively.  Use Qnumberp for
line-spacing.
* src/data.c (store_symval_forwarding): Adjust to call the predicate.
* lisp/cus-start.el (toplevel): Only allow float values for
scroll-up-aggressively and scroll-down-aggressively.
Allow any number for line-spacing.

7 files changed, 67 insertions, 65 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 8611edd3bfc..19968c46aa8 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,9 @@
+2013-01-10  Dmitry Antipov  <dmantipov@yandex.ru>
+
+        * cus-start.el (toplevel): Only allow float values for
+        scroll-up-aggressively and scroll-down-aggressively.
+        Allow any number for line-spacing.
+
 2013-01-10  Stefan Monnier  <monnier@iro.umontreal.ca>
 
         * doc-view.el (doc-view-pdfdraw-program): Allow "pdfdraw" name.
diff --git a/lisp/cus-start.el b/lisp/cus-start.el
index 9d2c2750987..b954ed60baa 100644
--- a/lisp/cus-start.el
+++ b/lisp/cus-start.el
@@ -115,12 +115,12 @@ Leaving \"Default\" unchecked is equivalent with specifying a default of
                             (const :tag "On the right" (down . right))))
                (other :tag "On left, no arrows" t)))
              (scroll-up-aggressively windows
-                                     (choice (const :tag "off" nil) number)
+                                     (choice (const :tag "off" nil) float)
                                      "21.1")
              (scroll-down-aggressively windows
-                                       (choice (const :tag "off" nil) number)
+                                       (choice (const :tag "off" nil) float)
                                        "21.1")
-             (line-spacing display (choice (const :tag "none" nil) integer)
+             (line-spacing display (choice (const :tag "none" nil) number)
                            "22.1")
              (cursor-in-non-selected-windows
               cursor boolean nil
diff --git a/src/ChangeLog b/src/ChangeLog
index 6ce141331ec..55a233adcd7 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,23 @@
+2013-01-10  Dmitry Antipov  <dmantipov@yandex.ru>
+
+        Omit buffer_slot_type_mismatch and use generic predicates to enforce
+        the type of per-buffer values where appropriate.
+        * lisp.h (struct Lisp_Buffer_Objfwd): Rename slottype member to
+        predicate, which is how it's really used now.  Adjust comment.
+        * buffer.h (buffer_slot_type_mismatch): Remove prototype.
+        * buffer.c (buffer_slot_type_mismatch): Remove.
+        (DEFVAR_PER_BUFFER, defvar_per_buffer): Rename type argument to
+        predicate.  Adjust comment.
+        (syms_of_buffer): Use Qsymbolp for major-mode.  Use Qintegerp for
+        fill-column, left-margin, tab-width, buffer-saved-size,
+        left-margin-width, right-margin-width, left-fringe-width,
+        right-fringe-width, scroll-bar-width and buffer-display-count.
+        Use Qstringp for default-directory, buffer-file-name,
+        buffer-file-truename and buffer-auto-save-file-name.  Use Qfloatp for
+        scroll-up-aggressively and scroll-down-aggressively.  Use Qnumberp for
+        line-spacing.
+        * data.c (store_symval_forwarding): Adjust to call the predicate.
+
 2013-01-09  Juanma Barranquero  <lekktu@gmail.com>
 
         * w32.c (get_name_and_id, acl_set_file):
diff --git a/src/buffer.c b/src/buffer.c
index 51c4d9c71da..218ae1a7d11 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -4576,27 +4576,7 @@ evaporate_overlays (ptrdiff_t pos)
   for (; CONSP (hit_list); hit_list = XCDR (hit_list))
     Fdelete_overlay (XCAR (hit_list));
 }
-
-/* Somebody has tried to store a value with an unacceptable type
-   in the slot with offset OFFSET.  */
 
-void
-buffer_slot_type_mismatch (Lisp_Object newval, int type)
-{
-  Lisp_Object predicate;
-
-  switch (type)
-    {
-    case_Lisp_Int:    predicate = Qintegerp; break;
-    case Lisp_String: predicate = Qstringp;  break;
-    case Lisp_Symbol: predicate = Qsymbolp;  break;
-    default: emacs_abort ();
-    }
-
-  wrong_type_argument (predicate, newval);
-}
-
-
 /***********************************************************************
                          Allocation with mmap
  ***********************************************************************/
@@ -5370,25 +5350,23 @@ init_buffer (void)
   free (pwd);
 }
 
-/* Similar to defvar_lisp but define a variable whose value is the Lisp
-   Object stored in the current buffer.  address is the address of the slot
-   in the buffer that is current now. */
-
-/* TYPE is nil for a general Lisp variable.
-   An integer specifies a type; then only Lisp values
-   with that type code are allowed (except that nil is allowed too).
-   LNAME is the Lisp-level variable name.
-   VNAME is the name of the buffer slot.
-   DOC is a dummy where you write the doc string as a comment.  */
-#define DEFVAR_PER_BUFFER(lname, vname, type, doc)                      \
-  do {                                                                  \
-    static struct Lisp_Buffer_Objfwd bo_fwd;                            \
-    defvar_per_buffer (&bo_fwd, lname, vname, type);                    \
+/* Similar to defvar_lisp but define a variable whose value is the
+   Lisp_Object stored in the current buffer.  LNAME is the Lisp-level
+   variable name.  VNAME is the name of the buffer slot.  PREDICATE
+   is nil for a general Lisp variable.  If PREDICATE is non-nil, then
+   only Lisp values that satisfies the PREDICATE are allowed (except
+   that nil is allowed too).  DOC is a dummy where you write the doc
+   string as a comment.  */
+
+#define DEFVAR_PER_BUFFER(lname, vname, predicate, doc)         \
+  do {                                                          \
+    static struct Lisp_Buffer_Objfwd bo_fwd;                    \
+    defvar_per_buffer (&bo_fwd, lname, vname, predicate);       \
   } while (0)
 
 static void
 defvar_per_buffer (struct Lisp_Buffer_Objfwd *bo_fwd, const char *namestring,
-                   Lisp_Object *address, Lisp_Object type)
+                   Lisp_Object *address, Lisp_Object predicate)
 {
   struct Lisp_Symbol *sym;
   int offset;
@@ -5398,7 +5376,7 @@ defvar_per_buffer (struct Lisp_Buffer_Objfwd *bo_fwd, const char *namestring,
 
   bo_fwd->type = Lisp_Fwd_Buffer_Obj;
   bo_fwd->offset = offset;
-  bo_fwd->slottype = type;
+  bo_fwd->predicate = predicate;
   sym->declared_special = 1;
   sym->redirect = SYMBOL_FORWARDED;
   {
@@ -5661,7 +5639,7 @@ Decimal digits after the % specify field width to which to pad.  */);
                           doc: /* Value of `major-mode' for new buffers.  */);
 
   DEFVAR_PER_BUFFER ("major-mode", &BVAR (current_buffer, major_mode),
-                     make_number (Lisp_Symbol),
+                     Qsymbolp,
                      doc: /* Symbol for current buffer's major mode.
 The default value (normally `fundamental-mode') affects new buffers.
 A value of nil means to use the current buffer's major mode, provided
@@ -5692,17 +5670,17 @@ Use the command `abbrev-mode' to change this variable.  */);
                      doc: /* Non-nil if searches and matches should ignore case.  */);
 
   DEFVAR_PER_BUFFER ("fill-column", &BVAR (current_buffer, fill_column),
-                     make_number (Lisp_Int0),
+                     Qintegerp,
                      doc: /* Column beyond which automatic line-wrapping should happen.
 Interactively, you can set the buffer local value using \\[set-fill-column].  */);
 
   DEFVAR_PER_BUFFER ("left-margin", &BVAR (current_buffer, left_margin),
-                     make_number (Lisp_Int0),
+                     Qintegerp,
                      doc: /* Column for the default `indent-line-function' to indent to.
 Linefeed indents to this column in Fundamental mode.  */);
 
   DEFVAR_PER_BUFFER ("tab-width", &BVAR (current_buffer, tab_width),
-                     make_number (Lisp_Int0),
+                     Qintegerp,
                      doc: /* Distance between tab stops (for display of tab characters), in columns.
 This should be an integer greater than zero.  */);
 
@@ -5787,7 +5765,7 @@ visual lines rather than logical lines.  See the documentation of
 `visual-line-mode'.  */);
 
   DEFVAR_PER_BUFFER ("default-directory", &BVAR (current_buffer, directory),
-                     make_number (Lisp_String),
+                     Qstringp,
                      doc: /* Name of default directory of current buffer.  Should end with slash.
 To interactively change the default directory, use command `cd'.  */);
 
@@ -5800,18 +5778,18 @@ NOTE: This variable is not a hook;
 its value may not be a list of functions.  */);
 
   DEFVAR_PER_BUFFER ("buffer-file-name", &BVAR (current_buffer, filename),
-                     make_number (Lisp_String),
+                     Qstringp,
                      doc: /* Name of file visited in current buffer, or nil if not visiting a file.  */);
 
   DEFVAR_PER_BUFFER ("buffer-file-truename", &BVAR (current_buffer, file_truename),
-                     make_number (Lisp_String),
+                     Qstringp,
                      doc: /* Abbreviated truename of file visited in current buffer, or nil if none.
 The truename of a file is calculated by `file-truename'
 and then abbreviated with `abbreviate-file-name'.  */);
 
   DEFVAR_PER_BUFFER ("buffer-auto-save-file-name",
                      &BVAR (current_buffer, auto_save_file_name),
-                     make_number (Lisp_String),
+                     Qstringp,
                      doc: /* Name of file for auto-saving current buffer.
 If it is nil, that means don't auto-save this buffer.  */);
 
@@ -5823,7 +5801,7 @@ If it is nil, that means don't auto-save this buffer.  */);
 Backing up is done before the first time the file is saved.  */);
 
   DEFVAR_PER_BUFFER ("buffer-saved-size", &BVAR (current_buffer, save_length),
-                     make_number (Lisp_Int0),
+                     Qintegerp,
                      doc: /* Length of current buffer when last read in, saved or auto-saved.
 0 initially.
 -1 means auto-saving turned off until next real save.
@@ -5893,23 +5871,23 @@ In addition, a char-table has six extra slots to control the display of:
 See also the functions `display-table-slot' and `set-display-table-slot'.  */);
 
   DEFVAR_PER_BUFFER ("left-margin-width", &BVAR (current_buffer, left_margin_cols),
-                     Qnil,
+                     Qintegerp,
                      doc: /* Width of left marginal area for display of a buffer.
 A value of nil means no marginal area.  */);
 
   DEFVAR_PER_BUFFER ("right-margin-width", &BVAR (current_buffer, right_margin_cols),
-                     Qnil,
+                     Qintegerp,
                      doc: /* Width of right marginal area for display of a buffer.
 A value of nil means no marginal area.  */);
 
   DEFVAR_PER_BUFFER ("left-fringe-width", &BVAR (current_buffer, left_fringe_width),
-                     Qnil,
+                     Qintegerp,
                      doc: /* Width of this buffer's left fringe (in pixels).
 A value of 0 means no left fringe is shown in this buffer's window.
 A value of nil means to use the left fringe width from the window's frame.  */);
 
   DEFVAR_PER_BUFFER ("right-fringe-width", &BVAR (current_buffer, right_fringe_width),
-                     Qnil,
+                     Qintegerp,
                      doc: /* Width of this buffer's right fringe (in pixels).
 A value of 0 means no right fringe is shown in this buffer's window.
 A value of nil means to use the right fringe width from the window's frame.  */);
@@ -5920,7 +5898,7 @@ A value of nil means to use the right fringe width from the window's frame.  */)
 A value of nil means to display fringes between margins and buffer text.  */);
 
   DEFVAR_PER_BUFFER ("scroll-bar-width", &BVAR (current_buffer, scroll_bar_width),
-                     Qnil,
+                     Qintegerp,
                      doc: /* Width of this buffer's scroll bars in pixels.
 A value of nil means to use the scroll bar width from the window's frame.  */);
 
@@ -6000,7 +5978,7 @@ BITMAP is the corresponding fringe bitmap shown for the logical
 cursor type.  */);
 
   DEFVAR_PER_BUFFER ("scroll-up-aggressively",
-                     &BVAR (current_buffer, scroll_up_aggressively), Qnil,
+                     &BVAR (current_buffer, scroll_up_aggressively), Qfloatp,
                      doc: /* How far to scroll windows upward.
 If you move point off the bottom, the window scrolls automatically.
 This variable controls how far it scrolls.  The value nil, the default,
@@ -6013,7 +5991,7 @@ window scrolls by a full window height.  Meaningful values are
 between 0.0 and 1.0, inclusive.  */);
 
   DEFVAR_PER_BUFFER ("scroll-down-aggressively",
-                     &BVAR (current_buffer, scroll_down_aggressively), Qnil,
+                     &BVAR (current_buffer, scroll_down_aggressively), Qfloatp,
                      doc: /* How far to scroll windows downward.
 If you move point off the top, the window scrolls automatically.
 This variable controls how far it scrolls.  The value nil, the default,
@@ -6167,7 +6145,7 @@ then characters with property value PROP are invisible,
 and they have an ellipsis as well if ELLIPSIS is non-nil.  */);
 
   DEFVAR_PER_BUFFER ("buffer-display-count",
-                     &BVAR (current_buffer, display_count), Qnil,
+                     &BVAR (current_buffer, display_count), Qintegerp,
                      doc: /* A number incremented each time this buffer is displayed in a window.
 The function `set-window-buffer' increments it.  */);
 
@@ -6226,7 +6204,7 @@ cursor's appearance is instead controlled by the variable
 `cursor-in-non-selected-windows'.  */);
 
   DEFVAR_PER_BUFFER ("line-spacing",
-                     &BVAR (current_buffer, extra_line_spacing), Qnil,
+                     &BVAR (current_buffer, extra_line_spacing), Qnumberp,
                      doc: /* Additional space to put between lines when displaying a buffer.
 The space is measured in pixels, and put below lines on graphic displays,
 see `display-graphic-p'.
diff --git a/src/buffer.h b/src/buffer.h
index ec9c34b3eb3..b4cc21d675d 100644
--- a/src/buffer.h
+++ b/src/buffer.h
@@ -1078,7 +1078,6 @@ extern void set_buffer_internal_1 (struct buffer *);
 extern void set_buffer_temp (struct buffer *);
 extern Lisp_Object buffer_local_value_1 (Lisp_Object, Lisp_Object);
 extern void record_buffer (Lisp_Object);
-extern _Noreturn void buffer_slot_type_mismatch (Lisp_Object, int);
 extern void fix_overlays_before (struct buffer *, ptrdiff_t, ptrdiff_t);
 extern void mmap_set_vars (bool);
 
diff --git a/src/data.c b/src/data.c
index 50dc188684f..6622088b648 100644
--- a/src/data.c
+++ b/src/data.c
@@ -914,13 +914,11 @@ store_symval_forwarding (union Lisp_Fwd *valcontents, register Lisp_Object newva
     case Lisp_Fwd_Buffer_Obj:
       {
         int offset = XBUFFER_OBJFWD (valcontents)->offset;
-        Lisp_Object type = XBUFFER_OBJFWD (valcontents)->slottype;
+        Lisp_Object predicate = XBUFFER_OBJFWD (valcontents)->predicate;
 
-        if (!(NILP (type) || NILP (newval)
-              || (XINT (type) == Lisp_Int0
-                  ? INTEGERP (newval)
-                  : XTYPE (newval) == XINT (type))))
-          buffer_slot_type_mismatch (newval, XINT (type));
+        if (!NILP (predicate) && !NILP (newval)
+            && NILP (call1 (predicate, newval)))
+          wrong_type_argument (predicate, newval);
 
         if (buf == NULL)
           buf = current_buffer;
diff --git a/src/lisp.h b/src/lisp.h
index a0dcc9ab5f3..8db61d3623a 100644
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -1450,7 +1450,8 @@ struct Lisp_Buffer_Objfwd
   {
     enum Lisp_Fwd_Type type;    /* = Lisp_Fwd_Buffer_Obj */
     int offset;
-    Lisp_Object slottype; /* Qnil, Lisp_Int, Lisp_Symbol, or Lisp_String.  */
+    /* One of Qnil, Qintegerp, Qsymbolp, Qstringp, Qfloatp or Qnumberp.  */
+    Lisp_Object predicate;
   };
 
 /* struct Lisp_Buffer_Local_Value is used in a symbol value cell when