Re: detecting undefined variables--a new mixed approach

[Thomas Lauer <thomas.lauer@...>]

David Manura <dm.lua@math2.org> wrote:
> That shouldn't be necessary.  checkglobals() validates not just one function but
> also all functions lexically nested inside that function.

Hm... with this module

-- file: mymodule.lua
module('mymodule',package.seeall)
print(mymodule)
function foo(x) print(_G.testxxyx) end

print("_G:")
checkglobals(1,_G)
print("mymodule:")
checkglobals(1,mymodule)

I get some weird results. (I've changed checkglobals() so that it
doesn't terminate with the first undefined global but just keeps
printing.)

This is printed:

table: 008244E0
_G:
undefined variable "foo" at line 4
mymodule:
undefined variable "module" at line 2
undefined variable "package" at line 2
undefined variable "print" at line 3
undefined variable "mymodule" at line 3
undefined variable "print" at line 6
undefined variable "_G" at line 7
undefined variable "print" at line 8
undefined variable "mymodule" at line 9
undefined variable "print" at line 4
undefined variable "_G" at line 4
nil

The rawget() call in checkglobals() is too restrictive, methinks. How
about changing this call to env[name]:

if env[name]==nil then print('undefined variable "'..name..'"'..(linenum
and ' at line '..linenum or '')) end

This "less strict" mode could easily be triggered by an optional third
boolean parameter to checkglobals().

Another problem I ran into is that checkglobals() doesn't work well if
two or more modules are defined in one file. This may not be the
standard case but I have a few files which create more than one module
and then all hell breaks loose as all globals defined in module 1 are
flagged invalid if checkglobals() is called for module 2 and vice versa.

-- 
cheers  thomasl

web: http://thomaslauer.com/start