builtin/common/strict.lua

   1
   2 -- Always warn when creating a global variable, even outside of a function.
   3 -- This ignores mod namespaces (variables with the same name as the current mod).
   4 local WARN_INIT = false
   5
   6 local getinfo = debug.getinfo
   7
   8 function core.global_exists(name)
   9         if type(name) ~= "string" then
  10                 error("core.global_exists: " .. tostring(name) .. " is not a string")
  11         end
  12         return rawget(_G, name) ~= nil
  13 end
  14
  15
  16 local meta = {}
  17 local declared = {}
  18 -- Key is source file, line, and variable name; seperated by NULs
  19 local warned = {}
  20
  21 function meta:__newindex(name, value)
  22         local info = getinfo(2, "Sl")
  23         local desc = ("%s:%d"):format(info.short_src, info.currentline)
  24         if not declared[name] then
  25                 local warn_key = ("%s\0%d\0%s"):format(info.source,
  26                                 info.currentline, name)
  27                 if not warned[warn_key] and info.what ~= "main" and
  28                                 info.what ~= "C" then
  29                         core.log("warning", ("Assignment to undeclared "..
  30                                         "global %q inside a function at %s.")
  31                                 :format(name, desc))
  32                         warned[warn_key] = true
  33                 end
  34                 declared[name] = true
  35         end
  36         -- Ignore mod namespaces
  37         if WARN_INIT and name ~= core.get_current_modname() then
  38                 core.log("warning", ("Global variable %q created at %s.")
  39                         :format(name, desc))
  40         end
  41         rawset(self, name, value)
  42 end
  43
  44
  45 function meta:__index(name)
  46         local info = getinfo(2, "Sl")
  47         local warn_key = ("%s\0%d\0%s"):format(info.source, info.currentline, name)
  48         if not declared[name] and not warned[warn_key] and info.what ~= "C" then
  49                 core.log("warning", ("Undeclared global variable %q accessed at %s:%s")
  50                                 :format(name, info.short_src, info.currentline))
  51                 warned[warn_key] = true
  52         end
  53         return rawget(self, name)
  54 end
  55
  56 setmetatable(_G, meta)
  57