File

util/debug.lua @ 13039:9ddb344b9fab

util.human.io: Allow defining per column ellipsis function As an alternative to doing it in the mapper function. Could be useful in cases where one may want to put the ellipsis in the middle or beginning instead of the start.
author Kim Alvefur <zash@zash.se>
date Fri, 07 Apr 2023 13:00:58 +0200
parent 12975:d10957394a3c
line wrap: on
line source

-- Variables ending with these names will not
-- have their values printed ('password' includes
-- 'new_password', etc.)
--
-- luacheck: ignore 122/debug

local censored_names = {
	password = true;
	passwd = true;
	pass = true;
	pwd = true;
};
local optimal_line_length = 65;

local termcolours = require "prosody.util.termcolours";
local getstring = termcolours.getstring;
local styles;
do
	local _ = termcolours.getstyle;
	styles = {
		boundary_padding = _("bright");
		filename         = _("bright", "blue");
		level_num        = _("green");
		funcname         = _("yellow");
		location         = _("yellow");
	};
end

local function get_locals_table(thread, level)
	local locals = {};
	for local_num = 1, math.huge do
		local name, value;
		if thread then
			name, value = debug.getlocal(thread, level, local_num);
		else
			name, value = debug.getlocal(level+1, local_num);
		end
		if not name then break; end
		table.insert(locals, { name = name, value = value });
	end
	return locals;
end

local function get_upvalues_table(func)
	local upvalues = {};
	if func then
		for upvalue_num = 1, math.huge do
			local name, value = debug.getupvalue(func, upvalue_num);
			if not name then break; end
			if name == "" then name = ("[%d]"):format(upvalue_num); end
			table.insert(upvalues, { name = name, value = value });
		end
	end
	return upvalues;
end

local function string_from_var_table(var_table, max_line_len, indent_str)
	local var_string = {};
	local col_pos = 0;
	max_line_len = max_line_len or math.huge;
	indent_str = "\n"..(indent_str or "");
	for _, var in ipairs(var_table) do
		local name, value = var.name, var.value;
		if name:sub(1,1) ~= "(" then
			if type(value) == "string" then
				if censored_names[name:match("%a+$")] then
					value = "<hidden>";
				else
					value = ("%q"):format(value);
				end
			else
				value = tostring(value);
			end
			if #value > max_line_len then
				value = value:sub(1, max_line_len-3).."…";
			end
			local str = ("%s = %s"):format(name, tostring(value));
			col_pos = col_pos + #str;
			if col_pos > max_line_len then
				table.insert(var_string, indent_str);
				col_pos = 0;
			end
			table.insert(var_string, str);
		end
	end
	if #var_string == 0 then
		return nil;
	else
		return "{ "..table.concat(var_string, ", "):gsub(indent_str..", ", indent_str).." }";
	end
end

local function get_traceback_table(thread, start_level)
	local levels = {};
	for level = start_level, math.huge do
		local info;
		if thread then
			info = debug.getinfo(thread, level);
		else
			info = debug.getinfo(level+1);
		end
		if not info then break; end

		levels[(level-start_level)+1] = {
			level = level;
			info = info;
			locals = get_locals_table(thread, level+1);
			upvalues = get_upvalues_table(info.func);
		};
	end
	return levels;
end

local function build_source_boundary_marker(last_source_desc)
	local padding = string.rep("-", math.floor(((optimal_line_length - 6) - #last_source_desc)/2));
	return getstring(styles.boundary_padding, "v"..padding).." "..
		getstring(styles.filename, last_source_desc).." "..
		getstring(styles.boundary_padding, padding..(#last_source_desc%2==0 and "-v" or "v "));
end

local function _traceback(thread, message, level)

	-- Lua manual says: debug.traceback ([thread,] [message [, level]])
	-- I fathom this to mean one of:
	-- ()
	-- (thread)
	-- (message, level)
	-- (thread, message, level)

	if thread == nil then -- Defaults
		thread, message, level = coroutine.running(), message, level;
	elseif type(thread) == "string" then
		thread, message, level = coroutine.running(), thread, message;
	elseif type(thread) ~= "thread" then
		return nil; -- debug.traceback() does this
	end

	level = level or 0;

	message = message and (message.."\n") or "";

	-- +3 counts for this function, and the pcall() and wrapper above us, the +1... I don't know.
	local levels = get_traceback_table(thread, level+(thread == nil and 4 or 0));

	local last_source_desc;

	local lines = {};
	for nlevel, current_level in ipairs(levels) do
		local info = current_level.info;
		local line;
		local func_type = info.namewhat.." ";
		local source_desc = (info.short_src == "[C]" and "C code") or info.short_src or "Unknown";
		if func_type == " " then func_type = ""; end;
		if info.short_src == "[C]" then
			line = "[ C ] "..func_type.."C function "..getstring(styles.location, (info.name and ("%q"):format(info.name) or "(unknown name)"));
		elseif info.what == "main" then
			line = "[Lua] "..getstring(styles.location, info.short_src.." line "..info.currentline);
		else
			local name = info.name or " ";
			if name ~= " " then
				name = ("%q"):format(name);
			end
			if func_type == "global " or func_type == "local " then
				func_type = func_type.."function ";
			end
			line = "[Lua] "..getstring(styles.location, info.short_src.." line "..
				info.currentline).." in "..func_type..getstring(styles.funcname, name)..
				" (defined on line "..info.linedefined..")";
		end
		if source_desc ~= last_source_desc then -- Venturing into a new source, add marker for previous
			last_source_desc = source_desc;
			table.insert(lines, "\t "..build_source_boundary_marker(last_source_desc));
		end
		nlevel = nlevel-1;
		table.insert(lines, "\t"..(nlevel==0 and ">" or " ")..getstring(styles.level_num, "("..nlevel..") ")..line);
		local npadding = (" "):rep(#tostring(nlevel));
		if current_level.locals then
			local locals_str = string_from_var_table(current_level.locals, optimal_line_length, "\t            "..npadding);
			if locals_str then
				table.insert(lines, "\t    "..npadding.."Locals: "..locals_str);
			end
		end
		local upvalues_str = string_from_var_table(current_level.upvalues, optimal_line_length, "\t            "..npadding);
		if upvalues_str then
			table.insert(lines, "\t    "..npadding.."Upvals: "..upvalues_str);
		end
	end

--	table.insert(lines, "\t "..build_source_boundary_marker(last_source_desc));

	return message.."stack traceback:\n"..table.concat(lines, "\n");
end

local function traceback(...)
	local ok, ret = pcall(_traceback, ...);
	if not ok then
		return "Error in error handling: "..ret;
	end
	return ret;
end

local function use()
	debug.traceback = traceback;
end

return {
	get_locals_table = get_locals_table;
	get_upvalues_table = get_upvalues_table;
	string_from_var_table = string_from_var_table;
	get_traceback_table = get_traceback_table;
	traceback = traceback;
	use = use;
};