util/debug.lua

   1 -- Variables ending with these names will not
   2 -- have their values printed ('password' includes
   3 -- 'new_password', etc.)
   4 local censored_names = {
   5         password = true;
   6         passwd = true;
   7         pass = true;
   8         pwd = true;
   9 };
  10
  11 local function get_locals_table(level)
  12         level = level + 1; -- Skip this function itself
  13         local locals = {};
  14         for local_num = 1, math.huge do
  15                 local name, value = debug.getlocal(level, local_num);
  16                 if not name then break; end
  17                 table.insert(locals, { name = name, value = value });
  18         end
  19         return locals;
  20 end
  21
  22 local function get_upvalues_table(func)
  23         local upvalues = {};
  24         if func then
  25                 for upvalue_num = 1, math.huge do
  26                         local name, value = debug.getupvalue(func, upvalue_num);
  27                         if not name then break; end
  28                         table.insert(upvalues, { name = name, value = value });
  29                 end
  30         end
  31         return upvalues;
  32 end
  33
  34 local function string_from_var_table(var_table, max_line_len, indent_str)
  35         local var_string = {};
  36         local col_pos = 0;
  37         max_line_len = max_line_len or math.huge;
  38         indent_str = "\n"..(indent_str or "");
  39         for _, var in ipairs(var_table) do
  40                 local name, value = var.name, var.value;
  41                 if name:sub(1,1) ~= "(" then
  42                         if type(value) == "string" then
  43                                 if censored_names[name:match("%a+$")] then
  44                                         value = "<hidden>";
  45                                 else
  46                                         value = ("%q"):format(value);
  47                                 end
  48                         else
  49                                 value = tostring(value);
  50                         end
  51                         if #value > max_line_len then
  52                                 value = value:sub(1, max_line_len-3).."…";
  53                         end
  54                         local str = ("%s = %s"):format(name, tostring(value));
  55                         col_pos = col_pos + #str;
  56                         if col_pos > max_line_len then
  57                                 table.insert(var_string, indent_str);
  58                                 col_pos = 0;
  59                         end
  60                         table.insert(var_string, str);
  61                 end
  62         end
  63         if #var_string == 0 then
  64                 return nil;
  65         else
  66                 return "{ "..table.concat(var_string, ", "):gsub(indent_str..", ", indent_str).." }";
  67         end
  68 end
  69
  70 function get_traceback_table(thread, start_level)
  71         local levels = {};
  72         for level = start_level, math.huge do
  73                 local info;
  74                 if thread then
  75                         info = debug.getinfo(thread, level);
  76                 else
  77                         info = debug.getinfo(level);
  78                 end
  79                 if not info then break; end
  80
  81                 levels[(level-start_level)+1] = {
  82                         level = level;
  83                         info = info;
  84                         locals = get_locals_table(level);
  85                         upvalues = get_upvalues_table(info.func);
  86                 };
  87         end
  88         return levels;
  89 end
  90
  91 function debug.traceback(...)
  92         local ok, ret = pcall(debug._traceback, ...);
  93         if not ok then
  94                 return "Error in error handling: "..ret;
  95         end
  96         return ret;
  97 end
  98
  99 function debug._traceback(thread, message, level)
 100         if type(thread) ~= "thread" then
 101                 thread, message, level = coroutine.running(), thread, message;
 102         end
 103         if level and type(message) ~= "string" then
 104                 return nil, "invalid message";
 105         elseif not level then
 106                 if type(message) == "number" then
 107                         level, message = message, nil;
 108                 else
 109                         level = 2;
 110                 end
 111         end
 112
 113         message = message and (message.."\n") or "";
 114
 115         local levels = get_traceback_table(thread, level+2);
 116
 117         local lines = {};
 118         for nlevel, level in ipairs(levels) do
 119                 local info = level.info;
 120                 local line = "...";
 121                 local func_type = info.namewhat.." ";
 122                 if func_type == " " then func_type = ""; end;
 123                 if info.short_src == "[C]" then
 124                         line = "[ C ] "..func_type.."C function "..(info.name and ("%q"):format(info.name) or "(unknown name)")
 125                 elseif info.what == "main" then
 126                         line = "[Lua] "..info.short_src.." line "..info.currentline;
 127                 else
 128                         local name = info.name or " ";
 129                         if name ~= " " then
 130                                 name = ("%q"):format(name);
 131                         end
 132                         if func_type == "global " or func_type == "local " then
 133                                 func_type = func_type.."function ";
 134                         end
 135                         line = "[Lua] "..info.short_src.." line "..info.currentline.." in "..func_type..name.." defined on line "..info.linedefined;
 136                 end
 137                 nlevel = nlevel-1;
 138                 table.insert(lines, "\t"..(nlevel==0 and ">" or " ").."("..nlevel..") "..line);
 139                 local npadding = (" "):rep(#tostring(nlevel));
 140                 local locals_str = string_from_var_table(level.locals, 65, "\t            "..npadding);
 141                 if locals_str then
 142                         table.insert(lines, "\t    "..npadding.."Locals: "..locals_str);
 143                 end
 144                 local upvalues_str = string_from_var_table(level.upvalues, 65, "\t            "..npadding);
 145                 if upvalues_str then
 146                         table.insert(lines, "\t    "..npadding.."Upvals: "..upvalues_str);
 147                 end
 148         end
 149         return message.."stack traceback:\n"..table.concat(lines, "\n");
 150 end