1 files changed, 168 insertions, 0 deletions
diff --git a/scripts/map_install_src.lua b/scripts/map_install_src.lua
new file mode 100755
index 0000000..ffc9a30
--- /dev/null
+++ b/scripts/map_install_src.lua
@@ -0,0 +1,168 @@
+#!/usr/bin/env luajit
+-- SPDX-License-Identifier: GPL-3.0-or-later
+
+-- parse install commands from stdin
+-- input: PREFIX=... make install --dry-run --always-make
+-- output: <install path> <source path>
+-- (or sed commands if --sed was specified)
+
+output = 'list'
+if #arg > 1 or arg[1] == '-h' or arg[1] == '--help' then
+	print(string.format([[
+Read install commands and map install paths to paths in source directory.
+
+Usage:
+$ PREFIX=... make install --dry-run --always-make | %s
+
+Example output:
+/kresd/git/.local/lib/kdns_modules/policy.lua	modules/policy/policy.lua
+
+Option --sed will produce output suitable as input suitable for sed.]],
+				arg[0]))
+	os.exit(1)
+elseif #arg == 0 then
+	output = 'list'
+elseif arg[1] == '--sed' then
+	output = 'sed'
+else
+	print('Invalid arguments. See --help.')
+	os.exit(2)
+end
+
+-- remove double // from paths and remove trailing /
+function normalize_path(path)
+	assert(path)
+	repeat
+		path, changes = path:gsub('//', '/')
+	until changes == 0
+	return path:gsub('/$', '')
+end
+
+function is_opt(word)
+	return word:match('^-')
+end
+
+-- opts requiring additional argument to be skipped
+local ignored_opts_with_arg = {
+	['--backup'] = true,
+	['-g'] = true,
+	['--group'] = true,
+	['-m'] = true,
+	['--mode'] = true,
+	['-o'] = true,
+	['--owner'] = true,
+	['--strip-program'] = true,
+	['--suffix'] = true,
+}
+
+-- state machine junctions caused by --opts
+-- returns: new state (expect, mode) and target name if any
+function parse_opts(word, expect, mode)
+	if word == '--' then
+		return 'names', mode, nil -- no options anymore
+	elseif word == '-d' or word == '--directory' then
+		return 'opt_or_name', 'newdir', nil
+	elseif word == '-t' or word == '--target-directory' then
+		return 'targetdir', mode, nil
+	elseif word:match('^--target-directory=') then
+		return 'opt_or_name', mode, string.sub(word, 20)
+	elseif ignored_opts_with_arg[word] then
+		return 'ignore', mode, nil -- ignore next word
+	else
+		return expect, mode, nil -- unhandled opt
+	end
+end
+
+
+-- cmd: complete install command line: install -m 0644 -t dest src1 src2
+-- dirs: names known to be directories: name => true
+-- returns: updated dirs
+function process_cmd(cmd, dirs)
+	-- print('# ' .. cmd)
+	sanity_check(cmd)
+	local expect = 'install'
+	local mode = 'copy' -- copy or newdir
+	local target -- last argument or argument for install -t
+	local names = {} -- non-option arguments
+
+	for word in cmd:gmatch('%S+') do
+		if expect == 'install' then -- parsing 'install'
+			assert(word == 'install')
+			expect = 'opt_or_name'
+		elseif expect == 'opt_or_name' then
+			if is_opt(word) then
+				expect, mode, newtarget = parse_opts(word, expect, mode)
+				target = newtarget or target
+			else
+				if mode == 'copy' then
+					table.insert(names, word)
+				elseif mode == 'newdir' then
+					local path = normalize_path(word)
+					dirs[path] = true
+				else
+					assert(false, 'bad mode')
+				end
+			end
+		elseif expect == 'targetdir' then
+			local path = normalize_path(word)
+			dirs[path] = true
+			target = word
+			expect = 'opt_or_name'
+		elseif expect == 'names' then
+			table.insert(names, word)
+		elseif expect == 'ignore' then
+			expect = 'opt_or_name'
+		else
+			assert(false, 'bad expect')
+		end
+	end
+	if mode == 'newdir' then
+		-- no mapping to print, this cmd just created directory
+		return dirs
+	end
+
+	if not target then -- last argument is the target
+		target = table.remove(names)
+	end
+	assert(target, 'fatal: no target in install cmd')
+	target = normalize_path(target)
+
+	for _, name in pairs(names) do
+		basename = string.gsub(name, "(.*/)(.*)", "%2")
+		if not dirs[target] then
+			print('fatal: target directory "' .. target .. '" was not created yet!')
+			os.exit(2)
+		end
+		-- mapping installed name -> source name
+		if output == 'list' then
+			print(target .. '/' .. basename, name)
+		elseif output == 'sed' then
+			print(string.format([[s`%s`%s`g]],
+					    target .. '/' .. basename, name))
+		else
+			assert(false, 'unsupported output')
+		end
+	end
+	return dirs
+end
+
+function sanity_check(cmd)
+	-- shell quotation is not supported
+	assert(not cmd:match('"'), 'quotes " are not supported')
+	assert(not cmd:match("'"), "quotes ' are not supported")
+	assert(not cmd:match('\\'), "escapes like \\ are not supported")
+	assert(cmd:match('^install%s'), 'not an install command')
+end
+
+-- remember directories created by install -d so we can expand relative paths
+local dirs = {}
+while true do
+	local cmd = io.read("*line")
+	if not cmd then
+		break
+	end
+	local isinstall = cmd:match('^install%s')
+	if isinstall then
+		dirs = process_cmd(cmd, dirs)
+	end
+end