From: Russell Browne (russ_at_amc.com)
Date: Wed Jan 03 2001 - 18:42:36 GMT
ups/menudata.c is generated from the .c files in ups/menus, which are in
turn generated by the med3 program. The trialing members Terry mentions
are initialized at run time.
Does the RedHat compiler (gcc 2.96) generate warnings when trialing members
of a structure are allowed to default to zero? If so, is it worth while
to change med3 to quiet the warnings?
Terry, thanks very much for your changes to formf.c, ao_pt_uarea.c, and
wdbyte.c!
Russ Browne
Applied MicroSystems Corp.
Terry R. Friedrichsen wrote:
>
> ups/menudata.c initializes a whole boatload of MENU structures, a la:
>
> static MENU blockmen_MM1 = {
> 0x60,
> 0,
> "Expand",
> 101,
> -1,
> -1,
> 107,
> 41,
> 0,
> 0,
> 0,
> 0,
> 0,
> NULL,
> NULL,
> NULL,
> NULL,
> NULL,
> };
>
> Note that 18 values are supplied in the initializer.
>
> However, MENU is:
>
> typedef struct mnode {
> unsigned short me_flags;
> short me_pos; /* The position at which the field is divided */
> const char *me_cap; /* Caption to be displayed in the field */
> short me_rv; /* result to be returned */
> short me_xstart; /* The window area of this node */
> short me_ystart;
> short me_xend;
> short me_yend;
> short me_xcurs; /* cursor coordinates for cursor */
> short me_ycurs; /* relative popup menus */
> short me_colour;
> long me_fg_colour;
> long me_bg_colour;
> long me_save; /* For saving popup backgrounds */
> struct mnode * me_topleft; /* pointer to top or left sub-menu */
> struct mnode * me_botrite; /* pointer to b. or r. sub_menu */
> struct mnode * me_parent; /* pointer to parent */
> struct omenst *me_omen; /* pointer to open menu structure */
> int* me_toggle; /* For toggle items */
> int me_select_val; /* if >= 0, select value for exclusive group */
> } MENU;
>
> Note that there are 20 elements in the structure.
>
> The terminating 5 NULL values in the initializer are evidently to correspond
> to the 5 pointers near the end of the structure. However, there is an addi-
> tional value (int me_select_val) at the end of the structure which is unini-
> tialized. It looks, from the comment, as though initializing it to 0 might
> be correct.
>
> But that only accounts for one of the two missing values. Note that the NULL
> values begin at position 14 in the initializers, but begin at position 15 in
> the actual structure. This has the potential for being more serious, since
> the initializers don't all specify all NULL values for these pointers.
>
>
> Notice that, except for "const char *me_cap", which the initializers set cor-
> rectly, everything else before the NULLs is a numeric type. Taking a flyer
> here, I've assumed that the unaccounted-for initializer value (whichever ele-
> ment it belongs to) is supposed to be 0.
>
> Accordingly, every menu (all 338 of 'em!) requires an additional initializer
> value of 0 to be inserted after the 13th position, and an additional 0 ini-
> tializer at the end.
>
> Fortunately, this was easy to accomplish with Emacs - I'll save the bandwidth
> and not reproduce the context diff here (including the entire file would be
> shorter!).
>
> These changes made the C compiler happy, at any rate ...
>
> Terry R. Friedrichsen
>
> terry_at_venus.sunquest.com
>
This archive was generated by hypermail 2.1.4 : Wed Feb 13 2002 - 21:51:33 GMT