freebsd-dev/sys/kern/linker_if.m
Peter Wemm f41325db5f 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
2001-06-13 10:58:39 +00:00

98 lines
2.9 KiB
Objective-C

#
# Copyright (c) 2000 Doug Rabson
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
# SUCH DAMAGE.
#
# $FreeBSD$
#
#include <sys/linker.h>
INTERFACE linker;
#
# Lookup a symbol in the file's symbol table. If the symbol is not
# found then return ENOENT, otherwise zero.
#
METHOD int lookup_symbol {
linker_file_t file;
const char* name;
c_linker_sym_t* symp;
};
METHOD int symbol_values {
linker_file_t file;
c_linker_sym_t sym;
linker_symval_t* valp;
};
METHOD int search_symbol {
linker_file_t file;
caddr_t value;
c_linker_sym_t* symp;
long* diffp;
};
#
# Search for a linker set in a file. Return a pointer to the first
# entry (which is itself a pointer), and the number of entries.
# "stop" points to the entry beyond the last valid entry.
# If count, start or stop are NULL, they are not returned.
#
METHOD int lookup_set {
linker_file_t file;
const char* name;
void*** start;
void*** stop;
int* count;
};
#
# Unload a file, releasing dependancies and freeing storage.
#
METHOD void unload {
linker_file_t file;
};
#
# Load a file, returning the new linker_file_t in *result. If
# the class does not recognise the file type, zero should be
# returned, without modifying *result. If the file is
# recognised, the file should be loaded, *result set to the new
# file and zero returned. If some other error is detected an
# appropriate errno should be returned.
#
STATICMETHOD int load_file {
linker_class_t cls;
const char* filename;
linker_file_t* result;
};
STATICMETHOD int link_preload {
linker_class_t cls;
const char* filename;
linker_file_t* result;
};
STATICMETHOD int link_preload_finish {
linker_file_t file;
};