#!/bin/sh

# Script to create/update include/generated/autoksyms.h and dependency files
#
# Copyright:	(C) 2016  Linaro Limited
# Created by:	Nicolas Pitre, January 2016
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 2 as
# published by the Free Software Foundation.

# Create/update the include/generated/autoksyms.h file from the list
# of all module's needed symbols as recorded on the third line of
# .tmp_versions/*.mod files.
#
# For each symbol being added or removed, the corresponding dependency
# file's timestamp is updated to force a rebuild of the affected source
# file. All arguments passed to this script are assumed to be a command
# to be exec'd to trigger a rebuild of those files.

set -e

setglobal cur_ksyms_file = '"include/generated/autoksyms.h'"
setglobal new_ksyms_file = '"include/generated/autoksyms.h.tmpnew'"

proc info {
	if test $quiet != "silent_" {
		printf "  %-7s %s\n" $1 $2
	}
}

info "CHK" $cur_ksyms_file

# Use "make V=1" to debug this script.
match $KBUILD_VERBOSE {
with *1*
	set -x
	
}

# We need access to CONFIG_ symbols
match $(KCONFIG_CONFIG) {
with */*
	source "${KCONFIG_CONFIG}"
	
with *
	# Force using a file from the current directory
	source "./${KCONFIG_CONFIG}"
}

# In case it doesn't exist yet...
if test -e $cur_ksyms_file { touch $cur_ksyms_file; }

# Generate a new ksym list file with symbols needed by the current
# set of modules.
cat > $new_ksyms_file << """
/*
 * Automatically generated file; DO NOT EDIT.
 */

"""
sed -ns -e '3{s/ /\n/g;/^$/!p;}' "$MODVERDIR"/*.mod | sort -u |
while read sym {
	if test -n $CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX {
		setglobal sym = $(sym#_)
	}
	echo "#define __KSYM_$(sym) 1"
} >> "$new_ksyms_file"

# Special case for modversions (see modpost.c)
if test -n $CONFIG_MODVERSIONS {
	echo "#define __KSYM_module_layout 1" >> $new_ksyms_file
}

# Extract changes between old and new list and touch corresponding
# dependency files.
setglobal changed = $[
setglobal count = '0'
sort $cur_ksyms_file $new_ksyms_file | uniq -u |
sed -n 's/^#define __KSYM_\(.*\) 1/\1/p' | tr "A-Z_" "a-z/" |
while read sympath {
	if test -z $sympath { continue; }
	setglobal depfile = ""include/config/ksym/$(sympath).h""
	mkdir -p $[dirname $depfile]
	touch $depfile
	echo $shExpr('count += 1')
} | tail -1]
setglobal changed = $(changed:-0)

if test $changed -gt 0 {
	# Replace the old list with tne new one
	setglobal old = $[grep -c "^#define __KSYM_" $cur_ksyms_file || true]
	setglobal new = $[grep -c "^#define __KSYM_" $new_ksyms_file || true]
	info "KSYMS" "symbols: before=$old, after=$new, changed=$changed"
	info "UPD" $cur_ksyms_file
	mv -f $new_ksyms_file $cur_ksyms_file
	# Then trigger a rebuild of affected source files
	exec $ifsjoin(Argv)
} else {
	rm -f $new_ksyms_file
}