Emacs Wrestling Match: lisp.h vs rest of the includes

[Juanma Barranquero]

Now that Dan is doing a wonderful job of cleaning up the sources by
building them under different -W settings to detect problems, I've
been inspired to do the same thing.

Building under -Wredundant-decls generates *a lot* of warnings. Some
of them are difficult to avoid, for example the ones generated by
EXFUN. Others are easier; see the attached patch, for starters. It
fixes quite a few warnings generated by declarations duplicated in
lisp.h and the relevant includes (for example,
redisplay_preserve_echo_area is both in lisp.h and dispextern.h).

The problem with these changes is that they represent moving things in
the opposite direction of what I think would be right: from the
includes to lisp.h (not that I'm moving anything to lisp.h, just
keeping the declaration on lisp.h and removing the other one).

I'm sure there are a lot of historical reasons why lisp.h is such
humongous mass of disparate content (compilation time being, I
suspect, the first and main reason in the past). But now that lisp.h
is listed in the dependencies of all .c sources, that's not so
relevant anymore. I think we should make an effort to *remove* things
from lisp.h and back to where they belong. In some cases it will mean
adding more .h dependencies to some sources, and perhaps just for one,
or a few, external declarations. But it will be cleaner and more
maintenable IMO.

    Juanma




=== modified file 'src/dispextern.h'
--- src/dispextern.h    2010-08-09 09:35:21 +0000
+++ src/dispextern.h    2010-08-09 10:18:06 +0000
@@ -2925,7 +2925,6 @@
 void remember_mouse_glyph (struct frame *, int, int, NativeRectangle *);

 void mark_window_display_accurate (Lisp_Object, int);
-void redisplay_preserve_echo_area (int);
 int set_cursor_from_row (struct window *, struct glyph_row *,
                          struct glyph_matrix *, int, int, int, int);
 void init_iterator (struct it *, struct window *, EMACS_INT,
@@ -2946,7 +2945,6 @@
 int in_display_vector_p (struct it *);
 int frame_mode_line_height (struct frame *);
 void highlight_trailing_whitespace (struct frame *, struct glyph_row *);
-extern Lisp_Object Qtool_bar;
 extern Lisp_Object Vshow_trailing_whitespace;
 extern int mode_line_in_non_selected_windows;
 extern int redisplaying_p;
@@ -3088,7 +3086,6 @@
 void unrequest_sigio (void);
 int tabs_safe_p (int);
 void init_baud_rate (int);
-void init_sigio (int);

 /* Defined in xfaces.c */

@@ -3133,7 +3130,6 @@
 int compute_char_face (struct frame *, int, Lisp_Object);
 void free_all_realized_faces (Lisp_Object);
 void free_realized_face (struct frame *, struct face *);
-extern Lisp_Object Qforeground_color, Qbackground_color;
 extern Lisp_Object Qframe_set_background_mode;
 extern char unspecified_fg[], unspecified_bg[];

@@ -3245,8 +3241,6 @@
 void update_single_window (struct window *, int);
 void do_pending_window_change (int);
 void change_frame_size (struct frame *, int, int, int, int, int);
-void init_display (void);
-void syms_of_display (void);
 extern Lisp_Object Qredisplay_dont_pause;
 void spec_glyph_lookup_face (struct window *, GLYPH *);


=== modified file 'src/frame.h'
--- src/frame.h 2010-08-05 23:15:24 +0000
+++ src/frame.h 2010-08-09 03:05:28 +0000
@@ -825,7 +825,7 @@
        list_var = XCDR (list_var))


-extern Lisp_Object Qframep, Qframe_live_p;
+extern Lisp_Object Qframe_live_p;
 extern Lisp_Object Qtty, Qtty_type;
 extern Lisp_Object Qtty_color_mode;
 extern Lisp_Object Qterminal, Qterminal_live_p;
@@ -854,9 +854,6 @@

 extern Lisp_Object Vmouse_highlight;
 
-/* The currently selected frame.  */
-
-extern Lisp_Object selected_frame;

 /* Value is a pointer to the selected frame.  If the selected frame
    isn't live, abort.  */
@@ -1045,7 +1042,6 @@
 extern Lisp_Object Qborder_color, Qborder_width;
 extern Lisp_Object Qbuffer_predicate, Qbuffer_list, Qburied_buffer_list;
 extern Lisp_Object Qcursor_color, Qcursor_type;
-extern Lisp_Object Qfont;
 extern Lisp_Object Qbackground_color, Qforeground_color;
 extern Lisp_Object Qicon, Qicon_name, Qicon_type, Qicon_left, Qicon_top;
 extern Lisp_Object Qinternal_border_width;
@@ -1070,15 +1066,11 @@
 extern Lisp_Object Qheight, Qwidth;
 extern Lisp_Object Qminibuffer, Qmodeline;
 extern Lisp_Object Qx, Qw32, Qmac, Qpc, Qns;
-extern Lisp_Object Qvisible;
 extern Lisp_Object Qdisplay_type;
 extern Lisp_Object Qbackground_mode;

 extern Lisp_Object Qx_resource_name;

-extern Lisp_Object Qleft, Qright, Qtop, Qbox, Qbottom;
-extern Lisp_Object Qdisplay;
-
 extern Lisp_Object Qrun_hook_with_args;

 #ifdef HAVE_WINDOW_SYSTEM
@@ -1096,8 +1088,6 @@

 /* These are in frame.c  */

-extern Lisp_Object Vx_resource_name;
-extern Lisp_Object Vx_resource_class;
 extern Lisp_Object Vmenu_bar_mode, Vtool_bar_mode;



=== modified file 'src/w32.h'
--- src/w32.h   2010-01-13 08:35:10 +0000
+++ src/w32.h   2010-08-09 02:39:33 +0000
@@ -139,7 +139,6 @@
 extern void term_w32select (void);
 extern void syms_of_w32menu (void);
 extern void globals_of_w32menu (void);
-extern void syms_of_fontset (void);

 extern int _sys_read_ahead (int fd);
 extern int _sys_wait_accept (int fd);