#!/usr/bin/env bash

usage_desc() {
	sed 's/^\t//' <<EOF
	Updates the kernel ABI stablelist checksum information and symtypes
	for architecture ARCH.

	The file updates stablelist definition in \$REDHAT/kabi/*. It does not
	stage the newly updated stablelist.
EOF
}

emit_line_from_Module_symvers() {
	[ ! -e Module.symvers ] && return 1
	grep -P "\t$2\t" Module.symvers
}

emit_line() {
	local checksum="$1"
	local symbol="$2"
	local obj="${3:-unknown}"
	local macro="${4:-UNKNOWN_MACRO}"
	local namespace="${5:-}"

	if [ -z "${namespace:-}" ]; then
		printf "%s\t%s\t%s\t%s\n" $checksum $symbol $obj $macro
		return
	fi

	printf "%s\t%s\t%s\t%s\t%s\n" $checksum $symbol $obj $macro $namespace
}

cb_checksum_new() {
	local arch="$1"
	local symbol="$2"
	local checksum="$3"
	local file="$4"
	local symversions="$5"
	local symtypes="$6"
	local stable_entry=$REDHAT/kabi/kabi-module/kabi_$arch/$symbol
	local prev_csum="NULL"

	{
		printf "#0-\n"
		printf "#I:0\n"
		printf "#P:$file\n"
		if ! emit_line_from_Module_symvers $arch $symbol; then
			[ ${TEST:-0} -eq 0 ] && return 1
			emit_line $checksum $symbol null null
		fi
	} > $stable_entry

	echo2 "Added symbol \`$sym' for architecture \`$arch' ($checksum)."
	emit_line_from_Module_symvers $arch $symbol || :
}

cb_checksum_update() {
	local arch="$1"
	local symbol="$2"
	local checksum="$3"
	local file="$4"
	local symversions="$5"
	local symtypes="$6"

	local prev_index="$7"
	local prev_csum="$8"
	#prev_symbol $9 unused
	local prev_obj="${10}"
	local prev_macro="${11}"
	local prev_ns="${12:-}"

	local stable_entry=$REDHAT/kabi/kabi-module/kabi_$arch/$symbol
	local index=$(grep -v '^#' $stable_entry | wc -l)

	if [ "$prev_csum" = "$checksum" ]; then
		echo2 "Symbol checksum of \`$sym' for architecture \`$arch' unchanged."
		return
	fi

	sed -i -e "s#\#P:.*#\#P:$file#" -e "s/#I:[0-9]\+/#I:$index/" \
		$stable_entry
	if ! emit_line_from_Module_symvers $arch $symbol; then
		emit_line $checksum $symbol $prev_obj $prev_macro $prev_ns
	fi >> $stable_entry

	echo2 "Updated symbol \`$sym' for architecture \`$arch'" \
	      "($prev_csum -> $checksum)."
}

# Called whenever a new symbol checksum is obtained
# cb_checksum ARCH SYMBOL CHECKSUM FILE SYMVERSIONS_FILE SYMTYPES_FILE
cb_checksum() {
	local arch="$1"
	local symbol="$2"
	local checksum="$3"
	local symversions="$5"
	local symtypes="$6"
	local stable_entry=$REDHAT/kabi/kabi-module/kabi_$arch/$symbol

	cp $symtypes $REDHAT/kabi/kabi-module/kabi_$arch/.$symbol

	if [ -e $stable_entry ]; then
		prev_index=$(grep -Po "^#I:\K[0-9]+" $stable_entry)
		cb_checksum_update "$@" $prev_index $(
			IFS=' ' grep -v "^#" $stable_entry \
			| head -n$((${prev_index}+1)) \
			| tail -n1
		)
		return
	fi

	cb_checksum_new "$@"
}

# Called whenever the generate command finished successfully
cb_ready() {
	# no more symbols, nothing to do
	:
}

cd "$(git rev-parse --show-toplevel)"
REDHAT=${REDHAT:-$(pwd)/redhat/}

# Generate new symbol checksums and symvers files
. $REDHAT/kabi/symtype-generate