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                         if name == "" then name = ("[%d]"):format(upvalue_num); end
  51                         table.insert(upvalues, { name = name, value = value });
  52                 end
  53         end
  54         return upvalues;
  55 end
  56
  57 local function string_from_var_table(var_table, max_line_len, indent_str)
  58         local var_string = {};
  59         local col_pos = 0;
  60         max_line_len = max_line_len or math.huge;
  61         indent_str = "\n"..(indent_str or "");
  62         for _, var in ipairs(var_table) do
  63                 local name, value = var.name, var.value;
  64                 if name:sub(1,1) ~= "(" then
  65                         if type(value) == "string" then
  66                                 if censored_names[name:match("%a+$")] then
  67                                         value = "<hidden>";
  68                                 else
  69                                         value = ("%q"):format(value);
  70                                 end
  71                         else
  72                                 value = tostring(value);
  73                         end
  74                         if #value > max_line_len then
  75                                 value = value:sub(1, max_line_len-3).."…";
  76                         end
  77                         local str = ("%s = %s"):format(name, tostring(value));
  78                         col_pos = col_pos + #str;
  79                         if col_pos > max_line_len then
  80                                 table.insert(var_string, indent_str);
  81                                 col_pos = 0;
  82                         end
  83                         table.insert(var_string, str);
  84                 end
  85         end
  86         if #var_string == 0 then
  87                 return nil;
  88         else
  89                 return "{ "..table.concat(var_string, ", "):gsub(indent_str..", ", indent_str).." }";
  90         end
  91 end
  92
  93 local function get_traceback_table(thread, start_level)
  94         local levels = {};
  95         for level = start_level, math.huge do
  96                 local info;
  97                 if thread then
  98                         info = debug.getinfo(thread, level);
  99                 else
 100                         info = debug.getinfo(level+1);
 101                 end
 102                 if not info then break; end
 103
 104                 levels[(level-start_level)+1] = {
 105                         level = level;
 106                         info = info;
 107                         locals = get_locals_table(thread, level+(thread and 0 or 1));
 108                         upvalues = get_upvalues_table(info.func);
 109                 };
 110         end
 111         return levels;
 112 end
 113
 114 local function build_source_boundary_marker(last_source_desc)
 115         local padding = string.rep("-", math.floor(((optimal_line_length - 6) - #last_source_desc)/2));
 116         return getstring(styles.boundary_padding, "v"..padding).." "..
 117                 getstring(styles.filename, last_source_desc).." "..
 118                 getstring(styles.boundary_padding, padding..(#last_source_desc%2==0 and "-v" or "v "));
 119 end
 120
 121 local function _traceback(thread, message, level)
 122
 123         -- Lua manual says: debug.traceback ([thread,] [message [, level]])
 124         -- I fathom this to mean one of:
 125         -- ()
 126         -- (thread)
 127         -- (message, level)
 128         -- (thread, message, level)
 129
 130         if thread == nil then -- Defaults
 131                 thread, message, level = coroutine.running(), message, level;
 132         elseif type(thread) == "string" then
 133                 thread, message, level = coroutine.running(), thread, message;
 134         elseif type(thread) ~= "thread" then
 135                 return nil; -- debug.traceback() does this
 136         end
 137
 138         level = level or 0;
 139
 140         message = message and (message.."\n") or "";
 141
 142         -- +3 counts for this function, and the pcall() and wrapper above us, the +1... I don't know.
 143         local levels = get_traceback_table(thread, level+(thread == nil and 4 or 0));
 144
 145         local last_source_desc;
 146
 147         local lines = {};
 148         for nlevel, current_level in ipairs(levels) do
 149                 local info = current_level.info;
 150                 local line;
 151                 local func_type = info.namewhat.." ";
 152                 local source_desc = (info.short_src == "[C]" and "C code") or info.short_src or "Unknown";
 153                 if func_type == " " then func_type = ""; end;
 154                 if info.short_src == "[C]" then
 155                         line = "[ C ] "..func_type.."C function "..getstring(styles.location, (info.name and ("%q"):format(info.name) or "(unknown name)"));
 156                 elseif info.what == "main" then
 157                         line = "[Lua] "..getstring(styles.location, info.short_src.." line "..info.currentline);
 158                 else
 159                         local name = info.name or " ";
 160                         if name ~= " " then
 161                                 name = ("%q"):format(name);
 162                         end
 163                         if func_type == "global " or func_type == "local " then
 164                                 func_type = func_type.."function ";
 165                         end
 166                         line = "[Lua] "..getstring(styles.location, info.short_src.." line "..
 167                                 info.currentline).." in "..func_type..getstring(styles.funcname, name)..
 168                                 " (defined on line "..info.linedefined..")";
 169                 end
 170                 if source_desc ~= last_source_desc then -- Venturing into a new source, add marker for previous
 171                         last_source_desc = source_desc;
 172                         table.insert(lines, "\t "..build_source_boundary_marker(last_source_desc));
 173                 end
 174                 nlevel = nlevel-1;
 175                 table.insert(lines, "\t"..(nlevel==0 and ">" or " ")..getstring(styles.level_num, "("..nlevel..") ")..line);
 176                 local npadding = (" "):rep(#tostring(nlevel));
 177                 if current_level.locals then
 178                         local locals_str = string_from_var_table(current_level.locals, optimal_line_length, "\t            "..npadding);
 179                         if locals_str then
 180                                 table.insert(lines, "\t    "..npadding.."Locals: "..locals_str);
 181                         end
 182                 end
 183                 local upvalues_str = string_from_var_table(current_level.upvalues, optimal_line_length, "\t            "..npadding);
 184                 if upvalues_str then
 185                         table.insert(lines, "\t    "..npadding.."Upvals: "..upvalues_str);
 186                 end
 187         end
 188
 189 --      table.insert(lines, "\t "..build_source_boundary_marker(last_source_desc));
 190
 191         return message.."stack traceback:\n"..table.concat(lines, "\n");
 192 end
 193
 194 local function traceback(...)
 195         local ok, ret = pcall(_traceback, ...);
 196         if not ok then
 197                 return "Error in error handling: "..ret;
 198         end
 199         return ret;
 200 end
 201
 202 local function use()
 203         debug.traceback = traceback;
 204 end
 205
 206 return {
 207         get_locals_table = get_locals_table;
 208         get_upvalues_table = get_upvalues_table;
 209         string_from_var_table = string_from_var_table;
 210         get_traceback_table = get_traceback_table;
 211         traceback = traceback;
 212         use = use;
 213 };