1#!/bin/sh
2# SPDX-License-Identifier: GPL-2.0-only
3
4# Script to create/update include/generated/autoksyms.h and dependency files
5#
6# Copyright:	(C) 2016  Linaro Limited
7# Created by:	Nicolas Pitre, January 2016
8#
9
10# Create/update the include/generated/autoksyms.h file from the list
11# of all module's needed symbols as recorded on the second line of *.mod files.
12#
13# For each symbol being added or removed, the corresponding dependency
14# file's timestamp is updated to force a rebuild of the affected source
15# file. All arguments passed to this script are assumed to be a command
16# to be exec'd to trigger a rebuild of those files.
17
18set -e
19
20cur_ksyms_file="include/generated/autoksyms.h"
21new_ksyms_file="include/generated/autoksyms.h.tmpnew"
22
23info() {
24	if [ "$quiet" != "silent_" ]; then
25		printf "  %-7s %s\n" "$1" "$2"
26	fi
27}
28
29info "CHK" "$cur_ksyms_file"
30
31# Use "make V=1" to debug this script.
32case "$KBUILD_VERBOSE" in
33*1*)
34	set -x
35	;;
36esac
37
38# We need access to CONFIG_ symbols
39. include/config/auto.conf
40
41# Generate a new ksym list file with symbols needed by the current
42# set of modules.
43cat > "$new_ksyms_file" << EOT
44/*
45 * Automatically generated file; DO NOT EDIT.
46 */
47
48EOT
49sed 's/ko$/mod/' modules.order |
50xargs -n1 sed -n -e '2{s/ /\n/g;/^$/!p;}' -- |
51sort -u |
52sed -e 's/\(.*\)/#define __KSYM_\1 1/' >> "$new_ksyms_file"
53
54# Special case for modversions (see modpost.c)
55if [ -n "$CONFIG_MODVERSIONS" ]; then
56	echo "#define __KSYM_module_layout 1" >> "$new_ksyms_file"
57fi
58
59# Extract changes between old and new list and touch corresponding
60# dependency files.
61changed=$(
62count=0
63sort "$cur_ksyms_file" "$new_ksyms_file" | uniq -u |
64sed -n 's/^#define __KSYM_\(.*\) 1/\1/p' | tr "A-Z_" "a-z/" |
65while read sympath; do
66	if [ -z "$sympath" ]; then continue; fi
67	depfile="include/ksym/${sympath}.h"
68	mkdir -p "$(dirname "$depfile")"
69	touch "$depfile"
70	# Filesystems with coarse time precision may create timestamps
71	# equal to the one from a file that was very recently built and that
72	# needs to be rebuild. Let's guard against that by making sure our
73	# dep files are always newer than the first file we created here.
74	while [ ! "$depfile" -nt "$new_ksyms_file" ]; do
75		touch "$depfile"
76	done
77	echo $((count += 1))
78done | tail -1 )
79changed=${changed:-0}
80
81if [ $changed -gt 0 ]; then
82	# Replace the old list with tne new one
83	old=$(grep -c "^#define __KSYM_" "$cur_ksyms_file" || true)
84	new=$(grep -c "^#define __KSYM_" "$new_ksyms_file" || true)
85	info "KSYMS" "symbols: before=$old, after=$new, changed=$changed"
86	info "UPD" "$cur_ksyms_file"
87	mv -f "$new_ksyms_file" "$cur_ksyms_file"
88	# Then trigger a rebuild of affected source files
89	exec $@
90else
91	rm -f "$new_ksyms_file"
92fi
93