candran/lib/LuaMinify/Scope.lua

--[[
This file is part of LuaMinify by stravant (https://github.com/stravant/LuaMinify).

LICENSE :
The MIT License (MIT)

Copyright (c) 2012-2013

Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
the Software, and to permit persons to whom the Software is furnished to do so,
subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
]]

local Scope = {
	new = function(self, parent)
		local s = {
			Parent = parent,
			Locals = { },
			Globals = { },
			oldLocalNamesMap = { },
			oldGlobalNamesMap = { },
			Children = { },
		}
		
		if parent then
			table.insert(parent.Children, s)
		end
		
		return setmetatable(s, { __index = self })
	end,
	
	AddLocal = function(self, v)
		table.insert(self.Locals, v)
	end,
	
	AddGlobal = function(self, v)
		table.insert(self.Globals, v)
	end,
	
	CreateLocal = function(self, name)
		local v
		v = self:GetLocal(name)
		if v then return v end
		v = { }
		v.Scope = self
		v.Name = name
		v.IsGlobal = false
		v.CanRename = true
		v.References = 1
		self:AddLocal(v)
		return v
	end,
	
	GetLocal = function(self, name)
		for k, var in pairs(self.Locals) do
			if var.Name == name then return var end
		end
		
		if self.Parent then
			return self.Parent:GetLocal(name)
		end
	end,
	
	GetOldLocal = function(self, name)
		if self.oldLocalNamesMap[name] then
			return self.oldLocalNamesMap[name]
		end
		return self:GetLocal(name)
	end,
	
	mapLocal = function(self, name, var)
		self.oldLocalNamesMap[name] = var
	end,
	
	GetOldGlobal = function(self, name)
		if self.oldGlobalNamesMap[name] then
			return self.oldGlobalNamesMap[name]
		end
		return self:GetGlobal(name)
	end,
	
	mapGlobal = function(self, name, var)
		self.oldGlobalNamesMap[name] = var
	end,
	
	GetOldVariable = function(self, name)
		return self:GetOldLocal(name) or self:GetOldGlobal(name)
	end,
	
	RenameLocal = function(self, oldName, newName)
		oldName = type(oldName) == 'string' and oldName or oldName.Name
		local found = false
		local var = self:GetLocal(oldName)
		if var then
			var.Name = newName
			self:mapLocal(oldName, var)
			found = true
		end
		if not found and self.Parent then
			self.Parent:RenameLocal(oldName, newName)
		end
	end,
	
	RenameGlobal = function(self, oldName, newName)
		oldName = type(oldName) == 'string' and oldName or oldName.Name
		local found = false
		local var = self:GetGlobal(oldName)
		if var then
			var.Name = newName
			self:mapGlobal(oldName, var)
			found = true
		end
		if not found and self.Parent then
			self.Parent:RenameGlobal(oldName, newName)
		end
	end,
	
	RenameVariable = function(self, oldName, newName)
		oldName = type(oldName) == 'string' and oldName or oldName.Name
		if self:GetLocal(oldName) then
			self:RenameLocal(oldName, newName)
		else
			self:RenameGlobal(oldName, newName)
		end
	end,
	
	GetAllVariables = function(self)
		local ret = self:getVars(true) -- down
		for k, v in pairs(self:getVars(false)) do -- up
			table.insert(ret, v)
		end
		return ret
	end,
	
	getVars = function(self, top)
		local ret = { }
		if top then
			for k, v in pairs(self.Children) do
				for k2, v2 in pairs(v:getVars(true)) do
					table.insert(ret, v2)
				end
			end
		else
			for k, v in pairs(self.Locals) do
				table.insert(ret, v)
			end
			for k, v in pairs(self.Globals) do
				table.insert(ret, v)
			end
			if self.Parent then
				for k, v in pairs(self.Parent:getVars(false)) do
					table.insert(ret, v)
				end
			end
		end
		return ret
	end,
	
	CreateGlobal = function(self, name)
		local v
		v = self:GetGlobal(name)
		if v then return v end
		v = { }
		v.Scope = self
		v.Name = name
		v.IsGlobal = true
		v.CanRename = true
		v.References = 1
		self:AddGlobal(v)
		return v
	end, 
	
	GetGlobal = function(self, name)
		for k, v in pairs(self.Globals) do
			if v.Name == name then return v end
		end
		
		if self.Parent then
			return self.Parent:GetGlobal(name)
		end
	end,
	
	GetVariable = function(self, name)
		return self:GetLocal(name) or self:GetGlobal(name)
	end,
	
	ObfuscateLocals = function(self, recommendedMaxLength, validNameChars)
		recommendedMaxLength = recommendedMaxLength or 7
		local chars = validNameChars or "QWERTYUIOPASDFGHJKLZXCVBNMqwertyuioplkjhgfdsazxcvbnm_"
		local chars2 = validNameChars or "QWERTYUIOPASDFGHJKLZXCVBNMqwertyuioplkjhgfdsazxcvbnm_1234567890"
		for _, var in pairs(self.Locals) do
			local id = ""
			local tries = 0
			repeat
				local n = math.random(1, #chars)
				id = id .. chars:sub(n, n)
				for i = 1, math.random(0, tries > 5 and 30 or recommendedMaxLength) do
					local n = math.random(1, #chars2)
					id = id .. chars2:sub(n, n)
				end
				tries = tries + 1
			until not self:GetVariable(id)
			self:RenameLocal(var.Name, id)
		end
	end,
}

return Scope