util/debug.lua

   1 -- Variables ending with these names will not
   2 -- have their values printed ('password' includes
   3 -- 'new_password', etc.)
   4 --
   5 -- luacheck: ignore 122/debug
   6
   7 local censored_names = {
   8         password = true;
   9         passwd = true;
  10         pass = true;
  11         pwd = true;
  12 };
  13 local optimal_line_length = 65;
  14
  15 local termcolours = require "util.termcolours";
  16 local getstring = termcolours.getstring;
  17 local styles;
  18 do
  19         local _ = termcolours.getstyle;
  20         styles = {
  21                 boundary_padding = _("bright");
  22                 filename         = _("bright", "blue");
  23                 level_num        = _("green");
  24                 funcname         = _("yellow");
  25                 location         = _("yellow");
  26         };
  27 end
  28
  29 local function get_locals_table(thread, level)
  30         local locals = {};
  31         for local_num = 1, math.huge do
  32                 local name, value;
  33                 if thread then
  34                         name, value = debug.getlocal(thread, level, local_num);
  35                 else
  36                         name, value = debug.getlocal(level+1, local_num);
  37                 end
  38                 if not name then break; end
  39                 table.insert(locals, { name = name, value = value });
  40         end
  41         return locals;
  42 end
  43
  44 local function get_upvalues_table(func)
  45         local upvalues = {};
  46         if func then
  47                 for upvalue_num = 1, math.huge do
  48                         local name, value = debug.getupvalue(func, upvalue_num);
  49                         if not name then break; end
  50                         table.insert(upvalues, { name = name, value = value });
  51                 end
  52         end
  53         return upvalues;
  54 end
  55
  56 local function string_from_var_table(var_table, max_line_len, indent_str)
  57         local var_string = {};
  58         local col_pos = 0;
  59         max_line_len = max_line_len or math.huge;
  60         indent_str = "\n"..(indent_str or "");
  61         for _, var in ipairs(var_table) do
  62                 local name, value = var.name, var.value;
  63                 if name:sub(1,1) ~= "(" then
  64                         if type(value) == "string" then
  65                                 if censored_names[name:match("%a+$")] then
  66                                         value = "<hidden>";
  67                                 else
  68                                         value = ("%q"):format(value);
  69                                 end
  70                         else
  71                                 value = tostring(value);
  72                         end
  73                         if #value > max_line_len then
  74                                 value = value:sub(1, max_line_len-3).."…";
  75                         end
  76                         local str = ("%s = %s"):format(name, tostring(value));
  77                         col_pos = col_pos + #str;
  78                         if col_pos > max_line_len then
  79                                 table.insert(var_string, indent_str);
  80                                 col_pos = 0;
  81                         end
  82                         table.insert(var_string, str);
  83                 end
  84         end
  85         if #var_string == 0 then
  86                 return nil;
  87         else
  88                 return "{ "..table.concat(var_string, ", "):gsub(indent_str..", ", indent_str).." }";
  89         end
  90 end
  91
  92 local function get_traceback_table(thread, start_level)
  93         local levels = {};
  94         for level = start_level, math.huge do
  95                 local info;
  96                 if thread then
  97                         info = debug.getinfo(thread, level);
  98                 else
  99                         info = debug.getinfo(level+1);
 100                 end
 101                 if not info then break; end
 102
 103                 levels[(level-start_level)+1] = {
 104                         level = level;
 105                         info = info;
 106                         locals = get_locals_table(thread, level+(thread and 0 or 1));
 107                         upvalues = get_upvalues_table(info.func);
 108                 };
 109         end
 110         return levels;
 111 end
 112
 113 local function build_source_boundary_marker(last_source_desc)
 114         local padding = string.rep("-", math.floor(((optimal_line_length - 6) - #last_source_desc)/2));
 115         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 "));
 116 end
 117
 118 local function _traceback(thread, message, level)
 119
 120         -- Lua manual says: debug.traceback ([thread,] [message [, level]])
 121         -- I fathom this to mean one of:
 122         -- ()
 123         -- (thread)
 124         -- (message, level)
 125         -- (thread, message, level)
 126
 127         if thread == nil then -- Defaults
 128                 thread, message, level = coroutine.running(), message, level;
 129         elseif type(thread) == "string" then
 130                 thread, message, level = coroutine.running(), thread, message;
 131         elseif type(thread) ~= "thread" then
 132                 return nil; -- debug.traceback() does this
 133         end
 134
 135         level = level or 0;
 136
 137         message = message and (message.."\n") or "";
 138
 139         -- +3 counts for this function, and the pcall() and wrapper above us, the +1... I don't know.
 140         local levels = get_traceback_table(thread, level+(thread == nil and 4 or 0));
 141
 142         local last_source_desc;
 143
 144         local lines = {};
 145         for nlevel, level in ipairs(levels) do
 146                 local info = level.info;
 147                 local line = "...";
 148                 local func_type = info.namewhat.." ";
 149                 local source_desc = (info.short_src == "[C]" and "C code") or info.short_src or "Unknown";
 150                 if func_type == " " then func_type = ""; end;
 151                 if info.short_src == "[C]" then
 152                         line = "[ C ] "..func_type.."C function "..getstring(styles.location, (info.name and ("%q"):format(info.name) or "(unknown name)"));
 153                 elseif info.what == "main" then
 154                         line = "[Lua] "..getstring(styles.location, info.short_src.." line "..info.currentline);
 155                 else
 156                         local name = info.name or " ";
 157                         if name ~= " " then
 158                                 name = ("%q"):format(name);
 159                         end
 160                         if func_type == "global " or func_type == "local " then
 161                                 func_type = func_type.."function ";
 162                         end
 163                         line = "[Lua] "..getstring(styles.location, info.short_src.." line "..info.currentline).." in "..func_type..getstring(styles.funcname, name).." (defined on line "..info.linedefined..")";
 164                 end
 165                 if source_desc ~= last_source_desc then -- Venturing into a new source, add marker for previous
 166                         last_source_desc = source_desc;
 167                         table.insert(lines, "\t "..build_source_boundary_marker(last_source_desc));
 168                 end
 169                 nlevel = nlevel-1;
 170                 table.insert(lines, "\t"..(nlevel==0 and ">" or " ")..getstring(styles.level_num, "("..nlevel..") ")..line);
 171                 local npadding = (" "):rep(#tostring(nlevel));
 172                 if level.locals then
 173                         local locals_str = string_from_var_table(level.locals, optimal_line_length, "\t            "..npadding);
 174                         if locals_str then
 175                                 table.insert(lines, "\t    "..npadding.."Locals: "..locals_str);
 176                         end
 177                 end
 178                 local upvalues_str = string_from_var_table(level.upvalues, optimal_line_length, "\t            "..npadding);
 179                 if upvalues_str then
 180                         table.insert(lines, "\t    "..npadding.."Upvals: "..upvalues_str);
 181                 end
 182         end
 183
 184 --      table.insert(lines, "\t "..build_source_boundary_marker(last_source_desc));
 185
 186         return message.."stack traceback:\n"..table.concat(lines, "\n");
 187 end
 188
 189 local function traceback(...)
 190         local ok, ret = pcall(_traceback, ...);
 191         if not ok then
 192                 return "Error in error handling: "..ret;
 193         end
 194         return ret;
 195 end
 196
 197 local function use()
 198         debug.traceback = traceback;
 199 end
 200
 201 return {
 202         get_locals_table = get_locals_table;
 203         get_upvalues_table = get_upvalues_table;
 204         string_from_var_table = string_from_var_table;
 205         get_traceback_table = get_traceback_table;
 206         traceback = traceback;
 207         use = use;
 208 };