With this commit, I hereby pronounce gensetdefs past its use-by date.

Replace the a.out emulation of 'struct linker_set' with something
a little more flexible.  <sys/linker_set.h> now provides macros for
accessing elements and completely hides the implementation.

The linker_set.h macros have been on the back burner in various
forms since 1998 and has ideas and code from Mike Smith (SET_FOREACH()),
John Polstra (ELF clue) and myself (cleaned up API and the conversion
of the rest of the kernel to use it).

The macros declare a strongly typed set.  They return elements with the
type that you declare the set with, rather than a generic void *.

For ELF, we use the magic ld symbols (__start_<setname> and
__stop_<setname>).  Thanks to Richard Henderson <rth@redhat.com> for the
trick about how to force ld to provide them for kld's.

For a.out, we use the old linker_set struct.

NOTE: the item lists are no longer null terminated.  This is why
the code impact is high in certain areas.

The runtime linker has a new method to find the linker set
boundaries depending on which backend format is in use.

linker sets are still module/kld unfriendly and should never be used
for anything that may be modular one day.

Reviewed by:	eivind

9 files changed, 30 insertions, 33 deletions

diff --git a/sys/dev/fb/fb.c b/sys/dev/fb/fb.c
index 3d92761..056988d 100644
--- a/sys/dev/fb/fb.c
+++ b/sys/dev/fb/fb.c
@@ -39,12 +39,15 @@
 #include <sys/module.h>
 #include <sys/uio.h>
 #include <sys/fbio.h>
+#include <sys/linker_set.h>
 
 #include <vm/vm.h>
 #include <vm/pmap.h>
 
 #include <dev/fb/fbreg.h>
 
+SET_DECLARE(videodriver_set, const video_driver_t);
+
 /* local arrays */
 
 /*
@@ -160,8 +163,8 @@ vid_register(video_adapter_t *adp)
 
 	adp->va_index = index;
 	adp->va_token = NULL;
-	list = (const video_driver_t **)videodriver_set.ls_items;
-	while ((p = *list++) != NULL) {
+	SET_FOREACH(list, videodriver_set) {
+		p = *list;
 		if (strcmp(p->name, adp->va_name) == 0) {
 			adapter[index] = adp;
 			vidsw[index] = p->vidsw;
@@ -192,8 +195,8 @@ video_switch_t
 	const video_driver_t **list;
 	const video_driver_t *p;
 
-	list = (const video_driver_t **)videodriver_set.ls_items;
-	while ((p = *list++) != NULL) {
+	SET_FOREACH(list, videodriver_set) {
+		p = *list;
 		if (strcmp(p->name, name) == 0)
 			return p->vidsw;
 	}
@@ -281,8 +284,8 @@ vid_configure(int flags)
 	const video_driver_t **list;
 	const video_driver_t *p;
 
-	list = (const video_driver_t **)videodriver_set.ls_items;
-	while ((p = *list++) != NULL) {
+	SET_FOREACH(list, videodriver_set) {
+		p = *list;
 		if (p->configure != NULL)
 			(*p->configure)(flags);
 	}
diff --git a/sys/dev/fb/fbreg.h b/sys/dev/fb/fbreg.h
index 7070f19..ba6c0e1 100644
--- a/sys/dev/fb/fbreg.h
+++ b/sys/dev/fb/fbreg.h
@@ -148,7 +148,6 @@ typedef struct video_driver {
 
 /* global variables */
 extern struct video_switch **vidsw;
-extern struct linker_set videodriver_set;
 
 /* functions for the video card driver */
 int		vid_register(video_adapter_t *adp);
diff --git a/sys/dev/kbd/kbd.c b/sys/dev/kbd/kbd.c
index 8ebba7e..ce55b65 100644
--- a/sys/dev/kbd/kbd.c
+++ b/sys/dev/kbd/kbd.c
@@ -54,6 +54,8 @@ typedef struct genkbd_softc {
 static	SLIST_HEAD(, keyboard_driver) keyboard_drivers =
  	SLIST_HEAD_INITIALIZER(keyboard_drivers);
 
+SET_DECLARE(kbddriver_set, const keyboard_driver_t);
+
 /* local arrays */
 
 /*
@@ -199,8 +201,8 @@ kbd_register(keyboard_t *kbd)
 			return index;
 		}
 	}
-	list = (const keyboard_driver_t **)kbddriver_set.ls_items;
-	while ((p = *list++) != NULL) {
+	SET_FOREACH(list, kbddriver_set) {
+		p = *list;
 		if (strcmp(p->name, kbd->kb_name) == 0) {
 			keyboard[index] = kbd;
 			kbdsw[index] = p->kbdsw;
@@ -254,8 +256,8 @@ keyboard_switch_t
 		if (strcmp(p->name, driver) == 0)
 			return p->kbdsw;
 	}
-	list = (const keyboard_driver_t **)kbddriver_set.ls_items;
-	while ((p = *list++) != NULL) {
+	SET_FOREACH(list, kbddriver_set) {
+		p = *list;
 		if (strcmp(p->name, driver) == 0)
 			return p->kbdsw;
 	}
@@ -393,8 +395,8 @@ kbd_configure(int flags)
 		if (p->configure != NULL)
 			(*p->configure)(flags);
 	}
-	list = (const keyboard_driver_t **)kbddriver_set.ls_items;
-	while ((p = *list++) != NULL) {
+	SET_FOREACH(list, kbddriver_set) {
+		p = *list;
 		if (p->configure != NULL)
 			(*p->configure)(flags);
 	}
diff --git a/sys/dev/kbd/kbdreg.h b/sys/dev/kbd/kbdreg.h
index de7d941..55e0cef 100644
--- a/sys/dev/kbd/kbdreg.h
+++ b/sys/dev/kbd/kbdreg.h
@@ -173,7 +173,6 @@ typedef struct keyboard_driver {
 
 /* global variables */
 extern keyboard_switch_t **kbdsw;
-extern struct linker_set kbddriver_set;
 
 /* functions for the keyboard driver */
 int			kbd_add_driver(keyboard_driver_t *driver);
diff --git a/sys/dev/syscons/scgfbrndr.c b/sys/dev/syscons/scgfbrndr.c
index 85c4418..6767610 100644
--- a/sys/dev/syscons/scgfbrndr.c
+++ b/sys/dev/syscons/scgfbrndr.c
@@ -80,8 +80,6 @@ static vr_draw_border_t		vga_grborder;
 
 static void			vga_nop(scr_stat *scp, ...);
 
-static struct linker_set	vga_set;
-
 static sc_rndr_sw_t txtrndrsw = {
 	vga_txtclear,
 	vga_txtborder,
diff --git a/sys/dev/syscons/scterm.c b/sys/dev/syscons/scterm.c
index 99fad98..5b9c2f4 100644
--- a/sys/dev/syscons/scterm.c
+++ b/sys/dev/syscons/scterm.c
@@ -36,6 +36,8 @@
 #include <dev/syscons/syscons.h>
 #include <dev/syscons/sctermvar.h>
 
+SET_DECLARE(scterm_set, sc_term_sw_t);
+
 /* exported subroutines */
 
 void
@@ -95,8 +97,8 @@ sc_term_sw_t
 			}
 		}
 	} else {
-		list = (sc_term_sw_t **)scterm_set.ls_items;
-		while ((p = *list++) != NULL) {
+		SET_FOREACH(list, scterm_set) {
+			p = *list;
 			if ((strcmp(name, p->te_name) == 0)
 			    || (strcmp(name, "*") == 0)) {
 				return p;
diff --git a/sys/dev/syscons/scvgarndr.c b/sys/dev/syscons/scvgarndr.c
index 85c4418..6767610 100644
--- a/sys/dev/syscons/scvgarndr.c
+++ b/sys/dev/syscons/scvgarndr.c
@@ -80,8 +80,6 @@ static vr_draw_border_t		vga_grborder;
 
 static void			vga_nop(scr_stat *scp, ...);
 
-static struct linker_set	vga_set;
-
 static sc_rndr_sw_t txtrndrsw = {
 	vga_txtclear,
 	vga_txtborder,
diff --git a/sys/dev/syscons/scvidctl.c b/sys/dev/syscons/scvidctl.c
index be9d1e6..72dc7db 100644
--- a/sys/dev/syscons/scvidctl.c
+++ b/sys/dev/syscons/scvidctl.c
@@ -40,6 +40,8 @@
 #include <dev/fb/fbreg.h>
 #include <dev/syscons/syscons.h>
 
+SET_DECLARE(scrndr_set, const sc_renderer_t);
+
 /* for compatibility with previous versions */
 /* 3.0-RELEASE used the following structure */
 typedef struct old_video_adapter {
@@ -803,8 +805,8 @@ sc_rndr_sw_t
 			}
 		}
 	} else {
-		list = (const sc_renderer_t **)scrndr_set.ls_items;
-		while ((p = *list++) != NULL) {
+		SET_FOREACH(list, scrndr_set) {
+			p = *list;
 			if ((strcmp(p->name, name) == 0)
 				&& (mode == p->mode)) {
 				scp->status &=
diff --git a/sys/dev/syscons/syscons.h b/sys/dev/syscons/syscons.h
index d2d605d..ef10f4d 100644
--- a/sys/dev/syscons/syscons.h
+++ b/sys/dev/syscons/syscons.h
@@ -342,8 +342,6 @@ typedef struct sc_term_sw {
 	sc_term_input_t		*te_input;
 } sc_term_sw_t;
 
-extern struct linker_set scterm_set;
-
 #define SCTERM_MODULE(name, sw)					\
 	DATA_SET(scterm_set, sw);				\
 	static int						\
@@ -398,8 +396,6 @@ typedef struct sc_renderer {
 	LIST_ENTRY(sc_renderer)	link;
 } sc_renderer_t;
 
-extern struct linker_set scrndr_set;
-
 #define RENDERER(name, mode, sw, set)				\
 	static struct sc_renderer scrndr_##name##_##mode## = {	\
 		#name, mode, &sw				\
@@ -408,25 +404,23 @@ extern struct linker_set scrndr_set;
 	DATA_SET(set, scrndr_##name##_##mode##)
 
 #define RENDERER_MODULE(name, set)				\
+	SET_DECLARE(set, sc_renderer_t);			\
 	static int						\
 	scrndr_##name##_event(module_t mod, int type, void *data) \
 	{							\
 		sc_renderer_t **list;				\
-		sc_renderer_t *p;				\
 		int error = 0;					\
 		switch (type) {					\
 		case MOD_LOAD:					\
-			list = (sc_renderer_t **)set.ls_items;	\
-			while ((p = *list++) != NULL) {		\
-				error = sc_render_add(p);	\
+			SET_FOREACH(list, set) {		\
+				error = sc_render_add(*list);	\
 				if (error)			\
 					break;			\
 			}					\
 			break;					\
 		case MOD_UNLOAD:				\
-			list = (sc_renderer_t **)set.ls_items;	\
-			while ((p = *list++) != NULL) {		\
-				error = sc_render_remove(p);	\
+			SET_FOREACH(list, set) {		\
+				error = sc_render_remove(*list);\
 				if (error)			\
 					break;			\
 			}					\