Lua 정적 분석기(전역변수 사용 detection)

local 로 선언되거지 않거나

g_ 로 시작하지 않는 선언되지 않는 global 변수를 찾아서 화면에 표시한다

 

#!/home/nop/lua-5.0/bin/lua



--[[ 

Usage: lualint [-r|-s] filename.lua [ [-r|-s] [filename.lua] ...]



lualint performs static analysis of Lua source code's usage of global
variables..  It uses luac's bytecode listing.  It reports all accesses
to undeclared global variables, which catches many typing errors in
variable names.  For example:

local really_aborting
local function abort() os.exit(1) end

if not os.getenv("HOME") then
	realy_aborting = true
    abortt()
end

reports:
  /tmp/example.lua:4: *** global SET of realy_aborting
  /tmp/example.lua:5: global get of abortt

It is primarily designed for use on LTN7-style modules, where each
source file only exports one global symbol.  (A module contained in
the file "foobar.lua" should only export the symbol "foobar".)

A "relaxed" mode is available for source not in LTN7 style.  It only
detects reads from globals that were never set.  The switch "-r" puts
lualint into relaxed mode for the following files; "-s" switches back
to strict.

Required packages are tracked, although not recursively.  If you call
"myext.process()" you should require "myext", and not depend on other
dependencies to load it.  LUA_PATH is followed as usual to find
requirements.

Some (not strictly LTN7) modules may wish to export other variables
into the global environment.  To do so, use the declare function:


declare "xpairs"
  function xpairs(node)
    [...]



Similarly, to quiet warnings about reading global variables you are
aware may be unavailable:


  lint_ignore "lua_fltk_version"
  if lua_fltk_version then print("fltk loaded") end


One way of defining these is in a module "declare.lua":

  function declare(s)
  end

  declare "lint_ignore"
  
  function lint_ignore(s)
  end



(Setting declare is OK, because it's in the "declare" module.)  These

functions don't have to do anything, or in fact actually exist!  They

can be in dead code:



  if false then declare "xpairs" end

    

This is because lualint only performs a rather primitive and cursory

scan of the bytecode.  Perhaps declarations should only be allowed in

the main chunk.



TODO:



The errors don't come out in any particular order.



Should switch to Rici's parser, which should do a much better job of

this, and allow detection of some other common situations.



CREDITS:



Jay Carlson (nop@nop.com)



This is all Ben Jackson's (ben@ben.com) fault, who did some similar

tricks in MOO.



]]





local function Set(l) 
  local t = {}
  for _,v in ipairs(l) do
    t[v] = true
  end
  return t
end



local ignoreget = Set{

"LUA_PATH", "_G", "_LOADED", "_TRACEBACK", "_VERSION", "__pow", "arg",

"assert", "collectgarbage", "coroutine", "debug", "dofile", "error",

"gcinfo", "getfenv", "getmetatable", "io", "ipairs", "loadfile",

"loadlib", "loadstring", "math", "newproxy", "next", "os", "pairs",

"pcall", "print", "rawequal", "rawget", "rawset", "require",

"setfenv", "setmetatable", "string", "table", "tonumber", "tostring",

"type", "unpack", "xpcall",

}



local function fileexists(fname)

  local f = io.open(fname)

  if f then 

    f:close()

    return true

  else

    return false

  end

end



-- borrowed from LTN11

local function locate(name)

  local path = LUA_PATH

  if type(path) ~= "string" then

    path = os.getenv "LUA_PATH" or "./?.lua"

  end

  for path in string.gfind(path, "[^;]+") do

    path = string.gsub(path, "?", name)

    if fileexists(path) then

      return path

    end

  end

  return nil

end





local function scanfile(filename)

  local modules = {}

  local declared = {}

  local lint_ignored = {}

  local refs = {}

  local saw_last = nil



  local context, curfunc



  if not fileexists(filename) then

    return nil, "file "..filename.." does not exist"

  end



  -- Run once to see if it parses correctly

  

  if not os.execute("luac -o lualint.tmp "..filename) then

    return nil, "file "..filename.." did not successfully parse"

  end



  if not fileexists("lualint.tmp") then

    return nil, "file "..filename.." did not successfully parse"

  end



  assert(os.remove("lualint.tmp"))



  local bc = assert(io.popen("luac -l -p "..filename))

  

  for line in bc:lines() do

    -- main <examples/xhtml2wiki.lua:0> (64 instructions, 256 bytes at 0x805c1a0)

    -- function <examples/xhtml2wiki.lua:13> (6 instructions, 24 bytes at 0x805c438)

    local found, _, type, fname = string.find(line, "(%w+) <([^>]+)>")

    if found then 

      if context == "main" then fname="*MAIN*" end

      curfunc = fname

    end

    

    -- print("sawlast", saw_last)

    --  2 [1] LOADK     1 1 ; "lazytree"

    local found, _, constname = string.find(line, '%sLOADK .-;%s"(.-)"')

    if saw_last and found then

      if saw_last == "require" then

        -- print("require", constname)

        table.insert(modules, constname)

      elseif saw_last == "declare" then

        -- print("declare", constname)

        table.insert(declared, constname)

      elseif saw_last == "lint_ignore" then

        lint_ignored[constname] = true

      end

    end

    

    --  4 [2] GETGLOBAL 0 0 ; require

    local found, _, lineno, instr, gname = string.find(line, "%[(%d+)%]%s+([SG]ETGLOBAL).-; (.+)")

    if found then

      local t = refs[curfunc] or {SETGLOBAL={n=0}, GETGLOBAL={n=0}}

      local err = {name=gname, lineno=lineno}

      table.insert(t[instr], err)

      refs[curfunc] = t

      saw_last = gname

    else

      saw_last = nil

    end

  end

  bc:close()

  return modules, declared, lint_ignored, refs

end



local found_sets = false

local found_gets = false

local parse_failed = false

local import_failed = true



-- print("args", arg[1])

local function lint(filename, relaxed)

  local modules, declared, lint_ignored, refs = scanfile(filename)



  if not modules then

    print(string.format("%s:%d: *** could not parse: %s ", filename, 1, declared))

    parse_failed = true

    return

  end

  

  local imported_declare_set = {}

  for i,module in ipairs(modules) do

    local path = locate(module)

    if not path then 

      print(string.format("%s:%d: could not find imported module %s ", filename, 1, module))

      import_failed = true

    else

      local success, imported_declare, _, _ = scanfile(path)

      if not success then

        print(string.format("%s:%d: could not parse import: %s ", path, 1, imported_declare))

        import_failed = true

      else

        for i,declared in ipairs(imported_declare) do

          imported_declare_set[declared] = true

        end

      end

    end

  end

    

  local moduleset = Set(modules)

  local declaredset = Set(declared)

  

  local self_name = nil

  do

    local _

    if string.find(filename, "/") then

      _, _, self_name = string.find(filename, ".-/(%w+)%.lua")

    else

      _,_,self_name = string.find(filename, "(%w+)%.lua")

    end

  end

  -- print("selfname", self_name)



  local was_set = {}

  

  local function will_warn_for(name)

    if relaxed and was_set[name] then

      return false

    end

    if name == self_name or

      lint_ignored[name] or

      ignoreget[name] or

      moduleset[name] or

      declaredset[name] or

      imported_declare_set[name] then

      return false

    end

    return true

  end



  for f,t in pairs(refs) do

    for _,r in ipairs(t.SETGLOBAL) do

      if r.name ~= self_name and not declaredset[r.name] then

        was_set[r.name] = true

        if not relaxed then

          if string.sub(r.name, 1, 2) ~= 'g_' then

            print(string.format("%s:%d: *** global SET of %s", filename, r.lineno, r.name))

          end

          found_sets = true

        end

      end

    end

  end



  for f,t in pairs(refs) do

    for _,r in ipairs(t.GETGLOBAL) do

      if will_warn_for(r.name) then

        if string.sub(r.name, 1, 2) ~= 'g_' then

          print(string.format("%s:%d: global get of %s", filename, r.lineno, r.name))

        end

        found_gets = true

      end

    end

  end

end



if arg.n == 0 then

  print("usage: lualint filename.lua [filename.lua ...]")

  os.exit(1)

end



local relaxed_mode = false



for i,v in ipairs(arg) do

  if v == "-r" then

    relaxed_mode = true

  elseif v == "-s" then

    relaxed_mode = false

  else

    lint(v, relaxed_mode)

  end

end



if parse_failed then

  os.exit(3)

elseif import_failed then

  os.exit(1)

elseif found_sets then

  os.exit(2)

elseif found_gets then

  os.exit(1)

else

  os.exit(0)

end

 

#!/home/nop/lua-5.0/bin/lua

 

--[[ 

 

Usage: lualint [-r|-s] filename.lua [ [-r|-s] [filename.lua] ...]

 

lualint performs static analysis of Lua source code's usage of global

variables..  It uses luac's bytecode listing.  It reports all accesses

to undeclared global variables, which catches many typing errors in

variable names.  For example:

 

  local really_aborting

  local function abort() os.exit(1) end

  if not os.getenv("HOME") then

    realy_aborting = true

    abortt()

  end

 

reports:

 

  /tmp/example.lua:4: *** global SET of realy_aborting

  /tmp/example.lua:5: global get of abortt

 

It is primarily designed for use on LTN7-style modules, where each

source file only exports one global symbol.  (A module contained in

the file "foobar.lua" should only export the symbol "foobar".)

 

A "relaxed" mode is available for source not in LTN7 style.  It only

detects reads from globals that were never set.  The switch "-r" puts

lualint into relaxed mode for the following files; "-s" switches back

to strict.

 

Required packages are tracked, although not recursively.  If you call

"myext.process()" you should require "myext", and not depend on other

dependencies to load it.  LUA_PATH is followed as usual to find

requirements.

 

Some (not strictly LTN7) modules may wish to export other variables

into the global environment.  To do so, use the declare function:

 

  declare "xpairs"

  function xpairs(node)

    [...]

 

Similarly, to quiet warnings about reading global variables you are

aware may be unavailable:

 

  lint_ignore "lua_fltk_version"

  if lua_fltk_version then print("fltk loaded") end

 

One way of defining these is in a module "declare.lua":

 

  function declare(s)

  end

  declare "lint_ignore"

  function lint_ignore(s)

  end

 

(Setting declare is OK, because it's in the "declare" module.)  These

functions don't have to do anything, or in fact actually exist!  They

can be in dead code:

 

  if false then declare "xpairs" end

    

This is because lualint only performs a rather primitive and cursory

scan of the bytecode.  Perhaps declarations should only be allowed in

the main chunk.

 

TODO:

 

The errors don't come out in any particular order.

 

Should switch to Rici's parser, which should do a much better job of

this, and allow detection of some other common situations.

 

CREDITS:

 

Jay Carlson (nop@nop.com)

 

This is all Ben Jackson's (ben@ben.com) fault, who did some similar

tricks in MOO.

 

]]

 

 

local function Set(l) 

  local t = {}

  for _,v in ipairs(l) do

    t[v] = true

  end

  return t

end

 

local ignoreget = Set{

"LUA_PATH", "_G", "_LOADED", "_TRACEBACK", "_VERSION", "__pow", "arg",

"assert", "collectgarbage", "coroutine", "debug", "dofile", "error",

"gcinfo", "getfenv", "getmetatable", "io", "ipairs", "loadfile",

"loadlib", "loadstring", "math", "newproxy", "next", "os", "pairs",

"pcall", "print", "rawequal", "rawget", "rawset", "require",

"setfenv", "setmetatable", "string", "table", "tonumber", "tostring",

"type", "unpack", "xpcall",

}

 

local function fileexists(fname)

  local f = io.open(fname)

  if f then 

    f:close()

    return true

  else

    return false

  end

end

 

-- borrowed from LTN11

local function locate(name)

  local path = LUA_PATH

  if type(path) ~= "string" then

    path = os.getenv "LUA_PATH" or "./?.lua"

  end

  for path in string.gfind(path, "[^;]+") do

    path = string.gsub(path, "?", name)

    if fileexists(path) then

      return path

    end

  end

  return nil

end

 

 

local function scanfile(filename)

  local modules = {}

  local declared = {}

  local lint_ignored = {}

  local refs = {}

  local saw_last = nil

 

  local context, curfunc

 

  if not fileexists(filename) then

    return nil, "file "..filename.." does not exist"

  end

 

  -- Run once to see if it parses correctly

  

  if not os.execute("luac -o lualint.tmp "..filename) then

    return nil, "file "..filename.." did not successfully parse"

  end

 

  if not fileexists("lualint.tmp") then

    return nil, "file "..filename.." did not successfully parse"

  end

 

  assert(os.remove("lualint.tmp"))

 

  local bc = assert(io.popen("luac -l -p "..filename))

  

  for line in bc:lines() do

    -- main <examples/xhtml2wiki.lua:0> (64 instructions, 256 bytes at 0x805c1a0)

    -- function <examples/xhtml2wiki.lua:13> (6 instructions, 24 bytes at 0x805c438)

    local found, _, type, fname = string.find(line, "(%w+) <([^>]+)>")

    if found then 

      if context == "main" then fname="*MAIN*" end

      curfunc = fname

    end

    

    -- print("sawlast", saw_last)

    --  2 [1] LOADK     1 1 ; "lazytree"

    local found, _, constname = string.find(line, '%sLOADK .-;%s"(.-)"')

    if saw_last and found then

      if saw_last == "require" then

        -- print("require", constname)

        table.insert(modules, constname)

      elseif saw_last == "declare" then

        -- print("declare", constname)

        table.insert(declared, constname)

      elseif saw_last == "lint_ignore" then

        lint_ignored[constname] = true

      end

    end

    

    --  4 [2] GETGLOBAL 0 0 ; require

    local found, _, lineno, instr, gname = string.find(line, "%[(%d+)%]%s+([SG]ETGLOBAL).-; (.+)")

    if found then

      local t = refs[curfunc] or {SETGLOBAL={n=0}, GETGLOBAL={n=0}}

      local err = {name=gname, lineno=lineno}

      table.insert(t[instr], err)

      refs[curfunc] = t

      saw_last = gname

    else

      saw_last = nil

    end

  end

  bc:close()

  return modules, declared, lint_ignored, refs

end

 

local found_sets = false

local found_gets = false

local parse_failed = false

local import_failed = true

 

-- print("args", arg[1])

local function lint(filename, relaxed)

  local modules, declared, lint_ignored, refs = scanfile(filename)

 

  if not modules then

    print(string.format("%s:%d: *** could not parse: %s ", filename, 1, declared))

    parse_failed = true

    return

  end

  

  local imported_declare_set = {}

  for i,module in ipairs(modules) do

    local path = locate(module)

    if not path then 

      print(string.format("%s:%d: could not find imported module %s ", filename, 1, module))

      import_failed = true

    else

      local success, imported_declare, _, _ = scanfile(path)

      if not success then

        print(string.format("%s:%d: could not parse import: %s ", path, 1, imported_declare))

        import_failed = true

      else

        for i,declared in ipairs(imported_declare) do

          imported_declare_set[declared] = true

        end

      end

    end

  end

    

  local moduleset = Set(modules)

  local declaredset = Set(declared)

  

  local self_name = nil

  do

    local _

    if string.find(filename, "/") then

      _, _, self_name = string.find(filename, ".-/(%w+)%.lua")

    else

      _,_,self_name = string.find(filename, "(%w+)%.lua")

    end

  end

  -- print("selfname", self_name)

 

  local was_set = {}

  

  local function will_warn_for(name)

    if relaxed and was_set[name] then

      return false

    end

    if name == self_name or

      lint_ignored[name] or

      ignoreget[name] or

      moduleset[name] or

      declaredset[name] or

      imported_declare_set[name] then

      return false

    end

    return true

  end

 

  for f,t in pairs(refs) do

    for _,r in ipairs(t.SETGLOBAL) do

      if r.name ~= self_name and not declaredset[r.name] then

        was_set[r.name] = true

        if not relaxed then

          if string.sub(r.name, 1, 2) ~= 'g_' then

            print(string.format("%s:%d: *** global SET of %s", filename, r.lineno, r.name))

          end

          found_sets = true

        end

      end

    end

  end

 

  for f,t in pairs(refs) do

    for _,r in ipairs(t.GETGLOBAL) do

      if will_warn_for(r.name) then

        if string.sub(r.name, 1, 2) ~= 'g_' then

          print(string.format("%s:%d: global get of %s", filename, r.lineno, r.name))

        end

        found_gets = true

      end

    end

  end

end

 

if arg.n == 0 then

  print("usage: lualint filename.lua [filename.lua ...]")

  os.exit(1)

end

 

local relaxed_mode = false

 

for i,v in ipairs(arg) do

  if v == "-r" then

    relaxed_mode = true

  elseif v == "-s" then

    relaxed_mode = false

  else

    lint(v, relaxed_mode)

  end

end

 

if parse_failed then

  os.exit(3)

elseif import_failed then

  os.exit(1)

elseif found_sets then

  os.exit(2)

elseif found_gets then

  os.exit(1)

else

  os.exit(0)

end