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