From 4b17905e0ff3e191832a8cd6a767b3a1cc3d12ca Mon Sep 17 00:00:00 2001
From: thorpej <thorpej@NetBSD.org>
Date: Fri, 1 Nov 2002 22:58:44 +0000
Subject: [PATCH] Add support for "link sets", which are arrays of pointers to
 objects gathered together in named sections by the linker.

---
 sys/sys/cdefs.h      | 51 +++++++++++++++++++++++++++++++++++++++++++-
 sys/sys/cdefs_aout.h | 28 +++++++++++++++++++++++-
 sys/sys/cdefs_elf.h  | 26 +++++++++++++++++++++-
 3 files changed, 102 insertions(+), 3 deletions(-)

diff --git a/sys/sys/cdefs.h b/sys/sys/cdefs.h
index 5fec394e0853..a60bc9c610b1 100644
--- a/sys/sys/cdefs.h
+++ b/sys/sys/cdefs.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: cdefs.h,v 1.44 2002/10/10 17:02:23 thorpej Exp $	*/
+/*	$NetBSD: cdefs.h,v 1.45 2002/11/01 22:58:44 thorpej Exp $	*/
 
 /*
  * Copyright (c) 1991, 1993
@@ -272,4 +272,53 @@
 #define	__predict_false(exp)	((exp) != 0)
 #endif
 
+/*
+ * Macros for manipulating "link sets".  Link sets are arrays of pointers
+ * to objects, which are gathered up by the linker.
+ *
+ * Object format-specific code has provided us with the following macros:
+ *
+ *	__link_set_add_text(set, sym)
+ *		Add a reference to the .text symbol `sym' to `set'.
+ *
+ *	__link_set_add_rodata(set, sym)
+ *		Add a reference to the .rodata symbol `sym' to `set'.
+ *
+ *	__link_set_add_data(set, sym)
+ *		Add a reference to the .data symbol `sym' to `set'.
+ *
+ *	__link_set_add_bss(set, sym)
+ *		Add a reference to the .bss symbol `sym' to `set'.
+ *
+ *	__link_set_decl(set, ptype)
+ *		Provide an extern declaration of the set `set', which
+ *		contains an array of the pointer type `ptype'.  This
+ *		macro must be used by any code which wishes to reference
+ *		the elements of a link set.
+ *
+ *	__link_set_start(set)
+ *		This points to the first slot in the link set.
+ *
+ *	__link_set_end(set)
+ *		This points to the (non-existent) slot after the last
+ *		entry in the link set.
+ *
+ *	__link_set_count(set)
+ *		Count the number of entries in link set `set'.
+ *
+ * In addition, we provide the following macros for accessing link sets:
+ *
+ *	__link_set_foreach(pvar, set)
+ *		Iterate over the link set `set'.  Because a link set is
+ *		an array of pointers, pvar must be declared as "type **pvar",
+ *		and the actual entry accessed as "*pvar".
+ *
+ *	__link_set_entry(set, idx)
+ *		Access the link set entry at index `idx' from set `set'.
+ */
+#define	__link_set_foreach(pvar, set)					\
+	for (pvar = __link_set_start(set); pvar < __link_set_end(set); pvar++)
+
+#define	__link_set_entry(set, idx)	(__link_set_begin(set)[idx])
+
 #endif /* !_SYS_CDEFS_H_ */
diff --git a/sys/sys/cdefs_aout.h b/sys/sys/cdefs_aout.h
index a348b8813446..fd0c7d340847 100644
--- a/sys/sys/cdefs_aout.h
+++ b/sys/sys/cdefs_aout.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: cdefs_aout.h,v 1.10 2002/05/11 11:57:14 itohy Exp $	*/
+/*	$NetBSD: cdefs_aout.h,v 1.11 2002/11/01 22:58:44 thorpej Exp $	*/
 
 /*
  * Written by J.T. Conklin <jtc@wimsey.com> 01/17/95.
@@ -68,4 +68,30 @@
 #define	__KERNEL_SCCSID(_n,_s)
 #define	__KERNEL_COPYRIGHT(_n, _s) __IDSTRING(__CONCAT(copyright,_n),_s)
 
+#ifdef __lint__
+#define	__link_set_make_entry(set, sym, type)				\
+	static void const * const __link_set_##set##_sym_##sym = &sym;	\
+	__asm(".stabs \"___link_set_" #set "\", " #type ", 0, 0, _" #sym)
+#else
+#define	__link_set_make_entry(set, sym, type)				\
+	extern void const * const __link_set_##set##_sym_##sym
+#endif /* __lint__ */
+
+#define	__link_set_add_text(set, sym)	__link_set_make_entry(set, sym, 23)
+#define	__link_set_add_rodata(set, sym)	__link_set_make_entry(set, sym, 23)
+#define	__link_set_add_data(set, sym)	__link_set_make_entry(set, sym, 25)
+#define	__link_set_add_bss(set, sym)	__link_set_make_entry(set, sym, 27)
+
+#define	__link_set_decl(set, ptype)					\
+extern struct {								\
+	int	__ls_length;						\
+	ptype	*__ls_items[1];						\
+} __link_set_##set
+
+#define	__link_set_start(set)	(&(__link_set_##set).__ls_items[0])
+#define	__link_set_end(set)						\
+	(&(__link_set_##set).__ls_items[(__link_set_##set).__ls_length])
+
+#define	__link_set_count(set)	((__link_set_##set).__ls_length)
+
 #endif /* !_SYS_CDEFS_AOUT_H_ */
diff --git a/sys/sys/cdefs_elf.h b/sys/sys/cdefs_elf.h
index 81129d5ded6f..27b51de085a6 100644
--- a/sys/sys/cdefs_elf.h
+++ b/sys/sys/cdefs_elf.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: cdefs_elf.h,v 1.12 2002/10/10 00:52:47 thorpej Exp $	*/
+/*	$NetBSD: cdefs_elf.h,v 1.13 2002/11/01 22:58:44 thorpej Exp $	*/
 
 /*
  * Copyright (c) 1995, 1996 Carnegie-Mellon University.
@@ -112,4 +112,28 @@
 #define	__KERNEL_COPYRIGHT(_n, _s)	__SECTIONSTRING(.copyright, _s)
 #endif
 
+#ifndef __lint__
+#define	__link_set_make_entry(set, sym)					\
+	static void const * const __link_set_##set##_sym_##sym		\
+	    __section("link_set_" #set) __unused = &sym
+#else
+#define	__link_set_make_entry(set, sym)					\
+	extern void const * const __link_set_##set##_sym_##sym
+#endif /* __lint__ */
+
+#define	__link_set_add_text(set, sym)	__link_set_make_entry(set, sym)
+#define	__link_set_add_rodata(set, sym)	__link_set_make_entry(set, sym)
+#define	__link_set_add_data(set, sym)	__link_set_make_entry(set, sym)
+#define	__link_set_add_bss(set, sym)	__link_set_make_entry(set, sym)
+
+#define	__link_set_decl(set, ptype)					\
+	extern ptype *__start_link_set_##set;				\
+	extern ptype *__stop_link_set_##set
+
+#define	__link_set_start(set)	(&__start_link_set_##set)
+#define	__link_set_end(set)	(&__stop_link_set_##set)
+
+#define	__link_set_count(set)						\
+	(__link_set_end(set) - __link_set_start(set))
+
 #endif /* !_SYS_CDEFS_ELF_H_ */