# HG changeset patch # User Matthew Wild # Date 1248487501 -3600 # Node ID 2d9fe676e684215cbb13b1bafa16f8ff2a7c0512 # Parent b119b560ca3dd9b8c09ad8591130af2b8fee8ea3 Add minify plugin diff -r b119b560ca3d -r 2d9fe676e684 minify/llex.lua --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/minify/llex.lua Sat Jul 25 03:05:01 2009 +0100 @@ -0,0 +1,355 @@ +--[[-------------------------------------------------------------------- + + llex.lua: Lua 5.1 lexical analyzer in Lua + This file is part of LuaSrcDiet, based on Yueliang material. + + Copyright (c) 2008 Kein-Hong Man + The COPYRIGHT file describes the conditions + under which this software may be distributed. + + See the ChangeLog for more information. + +----------------------------------------------------------------------]] + +--[[-------------------------------------------------------------------- +-- NOTES: +-- * This is a version of the native 5.1.x lexer from Yueliang 0.4.0, +-- with significant modifications to handle LuaSrcDiet's needs: +-- (1) llex.error is an optional error function handler +-- (2) seminfo for strings include their delimiters and no +-- translation operations are performed on them +-- * ADDED shbang handling has been added to support executable scripts +-- * NO localized decimal point replacement magic +-- * NO limit to number of lines +-- * NO support for compatible long strings (LUA_COMPAT_LSTR) +-- * Please read technotes.txt for more technical details. +----------------------------------------------------------------------]] + +local base = _G +local string = require "string" +module "llex" + +local find = string.find +local match = string.match +local sub = string.sub + +---------------------------------------------------------------------- +-- initialize keyword list, variables +---------------------------------------------------------------------- + +local kw = {} +for v in string.gmatch([[ +and break do else elseif end false for function if in +local nil not or repeat return then true until while]], "%S+") do + kw[v] = true +end + +-- NOTE: see init() for module variables (externally visible): +-- tok, seminfo, tokln + +local z, -- source stream + sourceid, -- name of source + I, -- position of lexer + buff, -- buffer for strings + ln -- line number + +---------------------------------------------------------------------- +-- add information to token listing +---------------------------------------------------------------------- + +local function addtoken(token, info) + local i = #tok + 1 + tok[i] = token + seminfo[i] = info + tokln[i] = ln +end + +---------------------------------------------------------------------- +-- handles line number incrementation and end-of-line characters +---------------------------------------------------------------------- + +local function inclinenumber(i, is_tok) + local sub = sub + local old = sub(z, i, i) + i = i + 1 -- skip '\n' or '\r' + local c = sub(z, i, i) + if (c == "\n" or c == "\r") and (c ~= old) then + i = i + 1 -- skip '\n\r' or '\r\n' + old = old..c + end + if is_tok then addtoken("TK_EOL", old) end + ln = ln + 1 + I = i + return i +end + +---------------------------------------------------------------------- +-- initialize lexer for given source _z and source name _sourceid +---------------------------------------------------------------------- + +function init(_z, _sourceid) + z = _z -- source + sourceid = _sourceid -- name of source + I = 1 -- lexer's position in source + ln = 1 -- line number + tok = {} -- lexed token list* + seminfo = {} -- lexed semantic information list* + tokln = {} -- line numbers for messages* + -- (*) externally visible thru' module + -------------------------------------------------------------------- + -- initial processing (shbang handling) + -------------------------------------------------------------------- + local p, _, q, r = find(z, "^(#[^\r\n]*)(\r?\n?)") + if p then -- skip first line + I = I + #q + addtoken("TK_COMMENT", q) + if #r > 0 then inclinenumber(I, true) end + end +end + +---------------------------------------------------------------------- +-- returns a chunk name or id, no truncation for long names +---------------------------------------------------------------------- + +function chunkid() + if sourceid and match(sourceid, "^[=@]") then + return sub(sourceid, 2) -- remove first char + end + return "[string]" +end + +---------------------------------------------------------------------- +-- formats error message and throws error +-- * a simplified version, does not report what token was responsible +---------------------------------------------------------------------- + +function errorline(s, line) + local e = error or base.error + e(string.format("%s:%d: %s", chunkid(), line or ln, s)) +end +local errorline = errorline + +------------------------------------------------------------------------ +-- count separators ("=") in a long string delimiter +------------------------------------------------------------------------ + +local function skip_sep(i) + local sub = sub + local s = sub(z, i, i) + i = i + 1 + local count = #match(z, "=*", i) -- note, take the length + i = i + count + I = i + return (sub(z, i, i) == s) and count or (-count) - 1 +end + +---------------------------------------------------------------------- +-- reads a long string or long comment +---------------------------------------------------------------------- + +local function read_long_string(is_str, sep) + local i = I + 1 -- skip 2nd '[' + local sub = sub + local c = sub(z, i, i) + if c == "\r" or c == "\n" then -- string starts with a newline? + i = inclinenumber(i) -- skip it + end + local j = i + while true do + local p, q, r = find(z, "([\r\n%]])", i) -- (long range) + if not p then + errorline(is_str and "unfinished long string" or + "unfinished long comment") + end + i = p + if r == "]" then -- delimiter test + if skip_sep(i) == sep then + buff = sub(z, buff, I) + I = I + 1 -- skip 2nd ']' + return buff + end + i = I + else -- newline + buff = buff.."\n" + i = inclinenumber(i) + end + end--while +end + +---------------------------------------------------------------------- +-- reads a string +---------------------------------------------------------------------- + +local function read_string(del) + local i = I + local find = find + local sub = sub + while true do + local p, q, r = find(z, "([\n\r\\\"\'])", i) -- (long range) + if p then + if r == "\n" or r == "\r" then + errorline("unfinished string") + end + i = p + if r == "\\" then -- handle escapes + i = i + 1 + r = sub(z, i, i) + if r == "" then break end -- (EOZ error) + p = find("abfnrtv\n\r", r, 1, true) + ------------------------------------------------------ + if p then -- special escapes + if p > 7 then + i = inclinenumber(i) + else + i = i + 1 + end + ------------------------------------------------------ + elseif find(r, "%D") then -- other non-digits + i = i + 1 + ------------------------------------------------------ + else -- \xxx sequence + local p, q, s = find(z, "^(%d%d?%d?)", i) + i = q + 1 + if s + 1 > 256 then -- UCHAR_MAX + errorline("escape sequence too large") + end + ------------------------------------------------------ + end--if p + else + i = i + 1 + if r == del then -- ending delimiter + I = i + return sub(z, buff, i - 1) -- return string + end + end--if r + else + break -- (error) + end--if p + end--while + errorline("unfinished string") +end + +------------------------------------------------------------------------ +-- main lexer function +------------------------------------------------------------------------ + +function llex() + local find = find + local match = match + while true do--outer + local i = I + -- inner loop allows break to be used to nicely section tests + while true do--inner + ---------------------------------------------------------------- + local p, _, r = find(z, "^([_%a][_%w]*)", i) + if p then + I = i + #r + if kw[r] then + addtoken("TK_KEYWORD", r) -- reserved word (keyword) + else + addtoken("TK_NAME", r) -- identifier + end + break -- (continue) + end + ---------------------------------------------------------------- + local p, _, r = find(z, "^(%.?)%d", i) + if p then -- numeral + if r == "." then i = i + 1 end + local _, q, r = find(z, "^%d*[%.%d]*([eE]?)", i) + i = q + 1 + if #r == 1 then -- optional exponent + if match(z, "^[%+%-]", i) then -- optional sign + i = i + 1 + end + end + local _, q = find(z, "^[_%w]*", i) + I = q + 1 + local v = sub(z, p, q) -- string equivalent + if not base.tonumber(v) then -- handles hex test also + errorline("malformed number") + end + addtoken("TK_NUMBER", v) + break -- (continue) + end + ---------------------------------------------------------------- + local p, q, r, t = find(z, "^((%s)[ \t\v\f]*)", i) + if p then + if t == "\n" or t == "\r" then -- newline + inclinenumber(i, true) + else + I = q + 1 -- whitespace + addtoken("TK_SPACE", r) + end + break -- (continue) + end + ---------------------------------------------------------------- + local r = match(z, "^%p", i) + if r then + buff = i + local p = find("-[\"\'.=<>~", r, 1, true) + if p then + -- two-level if block for punctuation/symbols + -------------------------------------------------------- + if p <= 2 then + if p == 1 then -- minus + local c = match(z, "^%-%-(%[?)", i) + if c then + i = i + 2 + local sep = -1 + if c == "[" then + sep = skip_sep(i) + end + if sep >= 0 then -- long comment + addtoken("TK_LCOMMENT", read_long_string(false, sep)) + else -- short comment + I = find(z, "[\n\r]", i) or (#z + 1) + addtoken("TK_COMMENT", sub(z, buff, I - 1)) + end + break -- (continue) + end + -- (fall through for "-") + else -- [ or long string + local sep = skip_sep(i) + if sep >= 0 then + addtoken("TK_LSTRING", read_long_string(true, sep)) + elseif sep == -1 then + addtoken("TK_OP", "[") + else + errorline("invalid long string delimiter") + end + break -- (continue) + end + -------------------------------------------------------- + elseif p <= 5 then + if p < 5 then -- strings + I = i + 1 + addtoken("TK_STRING", read_string(r)) + break -- (continue) + end + r = match(z, "^%.%.?%.?", i) -- .|..|... dots + -- (fall through) + -------------------------------------------------------- + else -- relational + r = match(z, "^%p=?", i) + -- (fall through) + end + end + I = i + #r + addtoken("TK_OP", r) -- for other symbols, fall through + break -- (continue) + end + ---------------------------------------------------------------- + local r = sub(z, i, i) + if r ~= "" then + I = i + 1 + addtoken("TK_OP", r) -- other single-char tokens + break + end + addtoken("TK_EOS", "") -- end of stream, + return -- exit here + ---------------------------------------------------------------- + end--while inner + end--while outer +end + +return base.getfenv() diff -r b119b560ca3d -r 2d9fe676e684 minify/lparser.lua --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/minify/lparser.lua Sat Jul 25 03:05:01 2009 +0100 @@ -0,0 +1,1295 @@ +--[[-------------------------------------------------------------------- + + lparser.lua: Lua 5.1 parser in Lua + This file is part of LuaSrcDiet, based on Yueliang material. + + Copyright (c) 2008 Kein-Hong Man + The COPYRIGHT file describes the conditions + under which this software may be distributed. + + See the ChangeLog for more information. + +----------------------------------------------------------------------]] + +--[[-------------------------------------------------------------------- +-- NOTES: +-- * This is a version of the native 5.1.x parser from Yueliang 0.4.0, +-- with significant modifications to handle LuaSrcDiet's needs: +-- (1) needs pre-built token tables instead of a module.method +-- (2) lparser.error is an optional error handler (from llex) +-- (3) not full parsing, currently fakes raw/unlexed constants +-- (4) parser() returns globalinfo, localinfo tables +-- * Please read technotes.txt for more technical details. +-- * NO support for 'arg' vararg functions (LUA_COMPAT_VARARG) +-- * A lot of the parser is unused, but might later be useful for +-- full-on parsing and analysis for a few measly bytes saved. +----------------------------------------------------------------------]] + +local base = _G +local string = require "string" +module "lparser" +local _G = base.getfenv() + +--[[-------------------------------------------------------------------- +-- variable and data structure initialization +----------------------------------------------------------------------]] + +---------------------------------------------------------------------- +-- initialization: main variables +---------------------------------------------------------------------- + +local toklist, -- grammar-only token tables (token table, + seminfolist, -- semantic information table, line number + toklnlist, -- table, cross-reference table) + xreflist, + tpos, -- token position + + line, -- start line # for error messages + lastln, -- last line # for ambiguous syntax chk + tok, seminfo, ln, xref, -- token, semantic info, line + nameref, -- proper position of token + fs, -- current function state + top_fs, -- top-level function state + + globalinfo, -- global variable information table + globallookup, -- global variable name lookup table + localinfo, -- local variable information table + ilocalinfo, -- inactive locals (prior to activation) + ilocalrefs -- corresponding references to activate + +-- forward references for local functions +local explist1, expr, block, exp1, body, chunk + +---------------------------------------------------------------------- +-- initialization: data structures +---------------------------------------------------------------------- + +local gmatch = string.gmatch + +local block_follow = {} -- lookahead check in chunk(), returnstat() +for v in gmatch("else elseif end until ", "%S+") do + block_follow[v] = true +end + +local stat_call = {} -- lookup for calls in stat() +for v in gmatch("if while do for repeat function local return break", "%S+") do + stat_call[v] = v.."_stat" +end + +local binopr_left = {} -- binary operators, left priority +local binopr_right = {} -- binary operators, right priority +for op, lt, rt in gmatch([[ +{+ 6 6}{- 6 6}{* 7 7}{/ 7 7}{% 7 7} +{^ 10 9}{.. 5 4} +{~= 3 3}{== 3 3} +{< 3 3}{<= 3 3}{> 3 3}{>= 3 3} +{and 2 2}{or 1 1} +]], "{(%S+)%s(%d+)%s(%d+)}") do + binopr_left[op] = lt + 0 + binopr_right[op] = rt + 0 +end + +local unopr = { ["not"] = true, ["-"] = true, + ["#"] = true, } -- unary operators +local UNARY_PRIORITY = 8 -- priority for unary operators + +--[[-------------------------------------------------------------------- +-- support functions +----------------------------------------------------------------------]] + +---------------------------------------------------------------------- +-- formats error message and throws error (duplicated from llex) +-- * a simplified version, does not report what token was responsible +---------------------------------------------------------------------- + +local function errorline(s, line) + local e = error or base.error + e(string.format("(source):%d: %s", line or ln, s)) +end + +---------------------------------------------------------------------- +-- handles incoming token, semantic information pairs +-- * NOTE: 'nextt' is named 'next' originally +---------------------------------------------------------------------- + +-- reads in next token +local function nextt() + lastln = toklnlist[tpos] + tok, seminfo, ln, xref + = toklist[tpos], seminfolist[tpos], toklnlist[tpos], xreflist[tpos] + tpos = tpos + 1 +end + +-- peek at next token (single lookahead for table constructor) +local function lookahead() + return toklist[tpos] +end + +---------------------------------------------------------------------- +-- throws a syntax error, or if token expected is not there +---------------------------------------------------------------------- + +local function syntaxerror(msg) + local tok = tok + if tok ~= "" and tok ~= "" then + if tok == "" then tok = seminfo end + tok = "'"..tok.."'" + end + errorline(msg.." near "..tok) +end + +local function error_expected(token) + syntaxerror("'"..token.."' expected") +end + +---------------------------------------------------------------------- +-- tests for a token, returns outcome +-- * return value changed to boolean +---------------------------------------------------------------------- + +local function testnext(c) + if tok == c then nextt(); return true end +end + +---------------------------------------------------------------------- +-- check for existence of a token, throws error if not found +---------------------------------------------------------------------- + +local function check(c) + if tok ~= c then error_expected(c) end +end + +---------------------------------------------------------------------- +-- verify existence of a token, then skip it +---------------------------------------------------------------------- + +local function checknext(c) + check(c); nextt() +end + +---------------------------------------------------------------------- +-- throws error if condition not matched +---------------------------------------------------------------------- + +local function check_condition(c, msg) + if not c then syntaxerror(msg) end +end + +---------------------------------------------------------------------- +-- verifies token conditions are met or else throw error +---------------------------------------------------------------------- + +local function check_match(what, who, where) + if not testnext(what) then + if where == ln then + error_expected(what) + else + syntaxerror("'"..what.."' expected (to close '"..who.."' at line "..where..")") + end + end +end + +---------------------------------------------------------------------- +-- expect that token is a name, return the name +---------------------------------------------------------------------- + +local function str_checkname() + check("") + local ts = seminfo + nameref = xref + nextt() + return ts +end + +---------------------------------------------------------------------- +-- adds given string s in string pool, sets e as VK +---------------------------------------------------------------------- + +local function codestring(e, s) + e.k = "VK" +end + +---------------------------------------------------------------------- +-- consume a name token, adds it to string pool +---------------------------------------------------------------------- + +local function checkname(e) + codestring(e, str_checkname()) +end + +--[[-------------------------------------------------------------------- +-- variable (global|local|upvalue) handling +-- * to track locals and globals, we can extend Yueliang's minimal +-- variable management code with little trouble +-- * entry point is singlevar() for variable lookups +-- * lookup tables (bl.locallist) are maintained awkwardly in the basic +-- block data structures, PLUS the function data structure (this is +-- an inelegant hack, since bl is nil for the top level of a function) +----------------------------------------------------------------------]] + +---------------------------------------------------------------------- +-- register a local variable, create local variable object, set in +-- to-activate variable list +-- * used in new_localvarliteral(), parlist(), fornum(), forlist(), +-- localfunc(), localstat() +---------------------------------------------------------------------- + +local function new_localvar(name, special) + local bl = fs.bl + local locallist + -- locate locallist in current block object or function root object + if bl then + locallist = bl.locallist + else + locallist = fs.locallist + end + -- build local variable information object and set localinfo + local id = #localinfo + 1 + localinfo[id] = { -- new local variable object + name = name, -- local variable name + xref = { nameref }, -- xref, first value is declaration + decl = nameref, -- location of declaration, = xref[1] + } + if special then -- "self" must be not be changed + localinfo[id].isself = true + end + -- this can override a local with the same name in the same scope + -- but first, keep it inactive until it gets activated + local i = #ilocalinfo + 1 + ilocalinfo[i] = id + ilocalrefs[i] = locallist +end + +---------------------------------------------------------------------- +-- actually activate the variables so that they are visible +-- * remember Lua semantics, e.g. RHS is evaluated first, then LHS +-- * used in parlist(), forbody(), localfunc(), localstat(), body() +---------------------------------------------------------------------- + +local function adjustlocalvars(nvars) + local sz = #ilocalinfo + -- i goes from left to right, in order of local allocation, because + -- of something like: local a,a,a = 1,2,3 which gives a = 3 + while nvars > 0 do + nvars = nvars - 1 + local i = sz - nvars + local id = ilocalinfo[i] -- local's id + local obj = localinfo[id] + local name = obj.name -- name of local + obj.act = xref -- set activation location + ilocalinfo[i] = nil + local locallist = ilocalrefs[i] -- ref to lookup table to update + ilocalrefs[i] = nil + local existing = locallist[name] -- if existing, remove old first! + if existing then -- do not overlap, set special + obj = localinfo[existing] -- form of rem, as -id + obj.rem = -id + end + locallist[name] = id -- activate, now visible to Lua + end +end + +---------------------------------------------------------------------- +-- remove (deactivate) variables in current scope (before scope exits) +-- * zap entire locallist tables since we are not allocating registers +-- * used in leaveblock(), close_func() +---------------------------------------------------------------------- + +local function removevars() + local bl = fs.bl + local locallist + -- locate locallist in current block object or function root object + if bl then + locallist = bl.locallist + else + locallist = fs.locallist + end + -- enumerate the local list at current scope and deactivate 'em + for name, id in base.pairs(locallist) do + local obj = localinfo[id] + obj.rem = xref -- set deactivation location + end +end + +---------------------------------------------------------------------- +-- creates a new local variable given a name +-- * skips internal locals (those starting with '('), so internal +-- locals never needs a corresponding adjustlocalvars() call +-- * special is true for "self" which must not be optimized +-- * used in fornum(), forlist(), parlist(), body() +---------------------------------------------------------------------- + +local function new_localvarliteral(name, special) + if string.sub(name, 1, 1) == "(" then -- can skip internal locals + return + end + new_localvar(name, special) +end + +---------------------------------------------------------------------- +-- search the local variable namespace of the given fs for a match +-- * returns localinfo index +-- * used only in singlevaraux() +---------------------------------------------------------------------- + +local function searchvar(fs, n) + local bl = fs.bl + local locallist + if bl then + locallist = bl.locallist + while locallist do + if locallist[n] then return locallist[n] end -- found + bl = bl.prev + locallist = bl and bl.locallist + end + end + locallist = fs.locallist + return locallist[n] or -1 -- found or not found (-1) +end + +---------------------------------------------------------------------- +-- handle locals, globals and upvalues and related processing +-- * search mechanism is recursive, calls itself to search parents +-- * used only in singlevar() +---------------------------------------------------------------------- + +local function singlevaraux(fs, n, var) + if fs == nil then -- no more levels? + var.k = "VGLOBAL" -- default is global variable + return "VGLOBAL" + else + local v = searchvar(fs, n) -- look up at current level + if v >= 0 then + var.k = "VLOCAL" + var.id = v + -- codegen may need to deal with upvalue here + return "VLOCAL" + else -- not found at current level; try upper one + if singlevaraux(fs.prev, n, var) == "VGLOBAL" then + return "VGLOBAL" + end + -- else was LOCAL or UPVAL, handle here + var.k = "VUPVAL" -- upvalue in this level + return "VUPVAL" + end--if v + end--if fs +end + +---------------------------------------------------------------------- +-- consume a name token, creates a variable (global|local|upvalue) +-- * used in prefixexp(), funcname() +---------------------------------------------------------------------- + +local function singlevar(v) + local name = str_checkname() + singlevaraux(fs, name, v) + ------------------------------------------------------------------ + -- variable tracking + ------------------------------------------------------------------ + if v.k == "VGLOBAL" then + -- if global being accessed, keep track of it by creating an object + local id = globallookup[name] + if not id then + id = #globalinfo + 1 + globalinfo[id] = { -- new global variable object + name = name, -- global variable name + xref = { nameref }, -- xref, first value is declaration + } + globallookup[name] = id -- remember it + else + local obj = globalinfo[id].xref + obj[#obj + 1] = nameref -- add xref + end + else + -- local/upvalue is being accessed, keep track of it + local id = v.id + local obj = localinfo[id].xref + obj[#obj + 1] = nameref -- add xref + end +end + +--[[-------------------------------------------------------------------- +-- state management functions with open/close pairs +----------------------------------------------------------------------]] + +---------------------------------------------------------------------- +-- enters a code unit, initializes elements +---------------------------------------------------------------------- + +local function enterblock(isbreakable) + local bl = {} -- per-block state + bl.isbreakable = isbreakable + bl.prev = fs.bl + bl.locallist = {} + fs.bl = bl +end + +---------------------------------------------------------------------- +-- leaves a code unit, close any upvalues +---------------------------------------------------------------------- + +local function leaveblock() + local bl = fs.bl + removevars() + fs.bl = bl.prev +end + +---------------------------------------------------------------------- +-- opening of a function +-- * top_fs is only for anchoring the top fs, so that parser() can +-- return it to the caller function along with useful output +-- * used in parser() and body() +---------------------------------------------------------------------- + +local function open_func() + local new_fs -- per-function state + if not fs then -- top_fs is created early + new_fs = top_fs + else + new_fs = {} + end + new_fs.prev = fs -- linked list of function states + new_fs.bl = nil + new_fs.locallist = {} + fs = new_fs +end + +---------------------------------------------------------------------- +-- closing of a function +-- * used in parser() and body() +---------------------------------------------------------------------- + +local function close_func() + removevars() + fs = fs.prev +end + +--[[-------------------------------------------------------------------- +-- other parsing functions +-- * for table constructor, parameter list, argument list +----------------------------------------------------------------------]] + +---------------------------------------------------------------------- +-- parse a function name suffix, for function call specifications +-- * used in primaryexp(), funcname() +---------------------------------------------------------------------- + +local function field(v) + -- field -> ['.' | ':'] NAME + local key = {} + nextt() -- skip the dot or colon + checkname(key) + v.k = "VINDEXED" +end + +---------------------------------------------------------------------- +-- parse a table indexing suffix, for constructors, expressions +-- * used in recfield(), primaryexp() +---------------------------------------------------------------------- + +local function yindex(v) + -- index -> '[' expr ']' + nextt() -- skip the '[' + expr(v) + checknext("]") +end + +---------------------------------------------------------------------- +-- parse a table record (hash) field +-- * used in constructor() +---------------------------------------------------------------------- + +local function recfield(cc) + -- recfield -> (NAME | '['exp1']') = exp1 + local key, val = {}, {} + if tok == "" then + checkname(key) + else-- tok == '[' + yindex(key) + end + checknext("=") + expr(val) +end + +---------------------------------------------------------------------- +-- emit a set list instruction if enough elements (LFIELDS_PER_FLUSH) +-- * note: retained in this skeleton because it modifies cc.v.k +-- * used in constructor() +---------------------------------------------------------------------- + +local function closelistfield(cc) + if cc.v.k == "VVOID" then return end -- there is no list item + cc.v.k = "VVOID" +end + +---------------------------------------------------------------------- +-- parse a table list (array) field +-- * used in constructor() +---------------------------------------------------------------------- + +local function listfield(cc) + expr(cc.v) +end + +---------------------------------------------------------------------- +-- parse a table constructor +-- * used in funcargs(), simpleexp() +---------------------------------------------------------------------- + +local function constructor(t) + -- constructor -> '{' [ field { fieldsep field } [ fieldsep ] ] '}' + -- field -> recfield | listfield + -- fieldsep -> ',' | ';' + local line = ln + local cc = {} + cc.v = {} + cc.t = t + t.k = "VRELOCABLE" + cc.v.k = "VVOID" + checknext("{") + repeat + if tok == "}" then break end + -- closelistfield(cc) here + local c = tok + if c == "" then -- may be listfields or recfields + if lookahead() ~= "=" then -- look ahead: expression? + listfield(cc) + else + recfield(cc) + end + elseif c == "[" then -- constructor_item -> recfield + recfield(cc) + else -- constructor_part -> listfield + listfield(cc) + end + until not testnext(",") and not testnext(";") + check_match("}", "{", line) + -- lastlistfield(cc) here +end + +---------------------------------------------------------------------- +-- parse the arguments (parameters) of a function declaration +-- * used in body() +---------------------------------------------------------------------- + +local function parlist() + -- parlist -> [ param { ',' param } ] + local nparams = 0 + if tok ~= ")" then -- is 'parlist' not empty? + repeat + local c = tok + if c == "" then -- param -> NAME + new_localvar(str_checkname()) + nparams = nparams + 1 + elseif c == "..." then + nextt() + fs.is_vararg = true + else + syntaxerror(" or '...' expected") + end + until fs.is_vararg or not testnext(",") + end--if + adjustlocalvars(nparams) +end + +---------------------------------------------------------------------- +-- parse the parameters of a function call +-- * contrast with parlist(), used in function declarations +-- * used in primaryexp() +---------------------------------------------------------------------- + +local function funcargs(f) + local args = {} + local line = ln + local c = tok + if c == "(" then -- funcargs -> '(' [ explist1 ] ')' + if line ~= lastln then + syntaxerror("ambiguous syntax (function call x new statement)") + end + nextt() + if tok == ")" then -- arg list is empty? + args.k = "VVOID" + else + explist1(args) + end + check_match(")", "(", line) + elseif c == "{" then -- funcargs -> constructor + constructor(args) + elseif c == "" then -- funcargs -> STRING + codestring(args, seminfo) + nextt() -- must use 'seminfo' before 'next' + else + syntaxerror("function arguments expected") + return + end--if c + f.k = "VCALL" +end + +--[[-------------------------------------------------------------------- +-- mostly expression functions +----------------------------------------------------------------------]] + +---------------------------------------------------------------------- +-- parses an expression in parentheses or a single variable +-- * used in primaryexp() +---------------------------------------------------------------------- + +local function prefixexp(v) + -- prefixexp -> NAME | '(' expr ')' + local c = tok + if c == "(" then + local line = ln + nextt() + expr(v) + check_match(")", "(", line) + elseif c == "" then + singlevar(v) + else + syntaxerror("unexpected symbol") + end--if c +end + +---------------------------------------------------------------------- +-- parses a prefixexp (an expression in parentheses or a single +-- variable) or a function call specification +-- * used in simpleexp(), assignment(), expr_stat() +---------------------------------------------------------------------- + +local function primaryexp(v) + -- primaryexp -> + -- prefixexp { '.' NAME | '[' exp ']' | ':' NAME funcargs | funcargs } + prefixexp(v) + while true do + local c = tok + if c == "." then -- field + field(v) + elseif c == "[" then -- '[' exp1 ']' + local key = {} + yindex(key) + elseif c == ":" then -- ':' NAME funcargs + local key = {} + nextt() + checkname(key) + funcargs(v) + elseif c == "(" or c == "" or c == "{" then -- funcargs + funcargs(v) + else + return + end--if c + end--while +end + +---------------------------------------------------------------------- +-- parses general expression types, constants handled here +-- * used in subexpr() +---------------------------------------------------------------------- + +local function simpleexp(v) + -- simpleexp -> NUMBER | STRING | NIL | TRUE | FALSE | ... | + -- constructor | FUNCTION body | primaryexp + local c = tok + if c == "" then + v.k = "VKNUM" + elseif c == "" then + codestring(v, seminfo) + elseif c == "nil" then + v.k = "VNIL" + elseif c == "true" then + v.k = "VTRUE" + elseif c == "false" then + v.k = "VFALSE" + elseif c == "..." then -- vararg + check_condition(fs.is_vararg == true, + "cannot use '...' outside a vararg function"); + v.k = "VVARARG" + elseif c == "{" then -- constructor + constructor(v) + return + elseif c == "function" then + nextt() + body(v, false, ln) + return + else + primaryexp(v) + return + end--if c + nextt() +end + +------------------------------------------------------------------------ +-- Parse subexpressions. Includes handling of unary operators and binary +-- operators. A subexpr is given the rhs priority level of the operator +-- immediately left of it, if any (limit is -1 if none,) and if a binop +-- is found, limit is compared with the lhs priority level of the binop +-- in order to determine which executes first. +-- * recursively called +-- * used in expr() +------------------------------------------------------------------------ + +local function subexpr(v, limit) + -- subexpr -> (simpleexp | unop subexpr) { binop subexpr } + -- * where 'binop' is any binary operator with a priority + -- higher than 'limit' + local op = tok + local uop = unopr[op] + if uop then + nextt() + subexpr(v, UNARY_PRIORITY) + else + simpleexp(v) + end + -- expand while operators have priorities higher than 'limit' + op = tok + local binop = binopr_left[op] + while binop and binop > limit do + local v2 = {} + nextt() + -- read sub-expression with higher priority + local nextop = subexpr(v2, binopr_right[op]) + op = nextop + binop = binopr_left[op] + end + return op -- return first untreated operator +end + +---------------------------------------------------------------------- +-- Expression parsing starts here. Function subexpr is entered with the +-- left operator (which is non-existent) priority of -1, which is lower +-- than all actual operators. Expr information is returned in parm v. +-- * used in cond(), explist1(), index(), recfield(), listfield(), +-- prefixexp(), while_stat(), exp1() +---------------------------------------------------------------------- + +-- this is a forward-referenced local +function expr(v) + -- expr -> subexpr + subexpr(v, 0) +end + +--[[-------------------------------------------------------------------- +-- third level parsing functions +----------------------------------------------------------------------]] + +------------------------------------------------------------------------ +-- parse a variable assignment sequence +-- * recursively called +-- * used in expr_stat() +------------------------------------------------------------------------ + +local function assignment(v) + local e = {} + local c = v.v.k + check_condition(c == "VLOCAL" or c == "VUPVAL" or c == "VGLOBAL" + or c == "VINDEXED", "syntax error") + if testnext(",") then -- assignment -> ',' primaryexp assignment + local nv = {} -- expdesc + nv.v = {} + primaryexp(nv.v) + -- lparser.c deals with some register usage conflict here + assignment(nv) + else -- assignment -> '=' explist1 + checknext("=") + explist1(e) + return -- avoid default + end + e.k = "VNONRELOC" +end + +---------------------------------------------------------------------- +-- parse a for loop body for both versions of the for loop +-- * used in fornum(), forlist() +---------------------------------------------------------------------- + +local function forbody(nvars, isnum) + -- forbody -> DO block + checknext("do") + enterblock(false) -- scope for declared variables + adjustlocalvars(nvars) + block() + leaveblock() -- end of scope for declared variables +end + +---------------------------------------------------------------------- +-- parse a numerical for loop, calls forbody() +-- * used in for_stat() +---------------------------------------------------------------------- + +local function fornum(varname) + -- fornum -> NAME = exp1, exp1 [, exp1] DO body + local line = line + new_localvarliteral("(for index)") + new_localvarliteral("(for limit)") + new_localvarliteral("(for step)") + new_localvar(varname) + checknext("=") + exp1() -- initial value + checknext(",") + exp1() -- limit + if testnext(",") then + exp1() -- optional step + else + -- default step = 1 + end + forbody(1, true) +end + +---------------------------------------------------------------------- +-- parse a generic for loop, calls forbody() +-- * used in for_stat() +---------------------------------------------------------------------- + +local function forlist(indexname) + -- forlist -> NAME {, NAME} IN explist1 DO body + local e = {} + -- create control variables + new_localvarliteral("(for generator)") + new_localvarliteral("(for state)") + new_localvarliteral("(for control)") + -- create declared variables + new_localvar(indexname) + local nvars = 1 + while testnext(",") do + new_localvar(str_checkname()) + nvars = nvars + 1 + end + checknext("in") + local line = line + explist1(e) + forbody(nvars, false) +end + +---------------------------------------------------------------------- +-- parse a function name specification +-- * used in func_stat() +---------------------------------------------------------------------- + +local function funcname(v) + -- funcname -> NAME {field} [':' NAME] + local needself = false + singlevar(v) + while tok == "." do + field(v) + end + if tok == ":" then + needself = true + field(v) + end + return needself +end + +---------------------------------------------------------------------- +-- parse the single expressions needed in numerical for loops +-- * used in fornum() +---------------------------------------------------------------------- + +-- this is a forward-referenced local +function exp1() + -- exp1 -> expr + local e = {} + expr(e) +end + +---------------------------------------------------------------------- +-- parse condition in a repeat statement or an if control structure +-- * used in repeat_stat(), test_then_block() +---------------------------------------------------------------------- + +local function cond() + -- cond -> expr + local v = {} + expr(v) -- read condition +end + +---------------------------------------------------------------------- +-- parse part of an if control structure, including the condition +-- * used in if_stat() +---------------------------------------------------------------------- + +local function test_then_block() + -- test_then_block -> [IF | ELSEIF] cond THEN block + nextt() -- skip IF or ELSEIF + cond() + checknext("then") + block() -- 'then' part +end + +---------------------------------------------------------------------- +-- parse a local function statement +-- * used in local_stat() +---------------------------------------------------------------------- + +local function localfunc() + -- localfunc -> NAME body + local v, b = {} + new_localvar(str_checkname()) + v.k = "VLOCAL" + adjustlocalvars(1) + body(b, false, ln) +end + +---------------------------------------------------------------------- +-- parse a local variable declaration statement +-- * used in local_stat() +---------------------------------------------------------------------- + +local function localstat() + -- localstat -> NAME {',' NAME} ['=' explist1] + local nvars = 0 + local e = {} + repeat + new_localvar(str_checkname()) + nvars = nvars + 1 + until not testnext(",") + if testnext("=") then + explist1(e) + else + e.k = "VVOID" + end + adjustlocalvars(nvars) +end + +---------------------------------------------------------------------- +-- parse a list of comma-separated expressions +-- * used in return_stat(), localstat(), funcargs(), assignment(), +-- forlist() +---------------------------------------------------------------------- + +-- this is a forward-referenced local +function explist1(e) + -- explist1 -> expr { ',' expr } + expr(e) + while testnext(",") do + expr(e) + end +end + +---------------------------------------------------------------------- +-- parse function declaration body +-- * used in simpleexp(), localfunc(), func_stat() +---------------------------------------------------------------------- + +-- this is a forward-referenced local +function body(e, needself, line) + -- body -> '(' parlist ')' chunk END + open_func() + checknext("(") + if needself then + new_localvarliteral("self", true) + adjustlocalvars(1) + end + parlist() + checknext(")") + chunk() + check_match("end", "function", line) + close_func() +end + +---------------------------------------------------------------------- +-- parse a code block or unit +-- * used in do_stat(), while_stat(), forbody(), test_then_block(), +-- if_stat() +---------------------------------------------------------------------- + +-- this is a forward-referenced local +function block() + -- block -> chunk + enterblock(false) + chunk() + leaveblock() +end + +--[[-------------------------------------------------------------------- +-- second level parsing functions, all with '_stat' suffix +-- * since they are called via a table lookup, they cannot be local +-- functions (a lookup table of local functions might be smaller...) +-- * stat() -> *_stat() +----------------------------------------------------------------------]] + +---------------------------------------------------------------------- +-- initial parsing for a for loop, calls fornum() or forlist() +-- * removed 'line' parameter (used to set debug information only) +-- * used in stat() +---------------------------------------------------------------------- + +function for_stat() + -- stat -> for_stat -> FOR (fornum | forlist) END + local line = line + enterblock(true) -- scope for loop and control variables + nextt() -- skip 'for' + local varname = str_checkname() -- first variable name + local c = tok + if c == "=" then + fornum(varname) + elseif c == "," or c == "in" then + forlist(varname) + else + syntaxerror("'=' or 'in' expected") + end + check_match("end", "for", line) + leaveblock() -- loop scope (`break' jumps to this point) +end + +---------------------------------------------------------------------- +-- parse a while-do control structure, body processed by block() +-- * used in stat() +---------------------------------------------------------------------- + +function while_stat() + -- stat -> while_stat -> WHILE cond DO block END + local line = line + nextt() -- skip WHILE + cond() -- parse condition + enterblock(true) + checknext("do") + block() + check_match("end", "while", line) + leaveblock() +end + +---------------------------------------------------------------------- +-- parse a repeat-until control structure, body parsed by chunk() +-- * originally, repeatstat() calls breakstat() too if there is an +-- upvalue in the scope block; nothing is actually lexed, it is +-- actually the common code in breakstat() for closing of upvalues +-- * used in stat() +---------------------------------------------------------------------- + +function repeat_stat() + -- stat -> repeat_stat -> REPEAT block UNTIL cond + local line = line + enterblock(true) -- loop block + enterblock(false) -- scope block + nextt() -- skip REPEAT + chunk() + check_match("until", "repeat", line) + cond() + -- close upvalues at scope level below + leaveblock() -- finish scope + leaveblock() -- finish loop +end + +---------------------------------------------------------------------- +-- parse an if control structure +-- * used in stat() +---------------------------------------------------------------------- + +function if_stat() + -- stat -> if_stat -> IF cond THEN block + -- {ELSEIF cond THEN block} [ELSE block] END + local line = line + local v = {} + test_then_block() -- IF cond THEN block + while tok == "elseif" do + test_then_block() -- ELSEIF cond THEN block + end + if tok == "else" then + nextt() -- skip ELSE + block() -- 'else' part + end + check_match("end", "if", line) +end + +---------------------------------------------------------------------- +-- parse a return statement +-- * used in stat() +---------------------------------------------------------------------- + +function return_stat() + -- stat -> return_stat -> RETURN explist + local e = {} + nextt() -- skip RETURN + local c = tok + if block_follow[c] or c == ";" then + -- return no values + else + explist1(e) -- optional return values + end +end + +---------------------------------------------------------------------- +-- parse a break statement +-- * used in stat() +---------------------------------------------------------------------- + +function break_stat() + -- stat -> break_stat -> BREAK + local bl = fs.bl + nextt() -- skip BREAK + while bl and not bl.isbreakable do -- find a breakable block + bl = bl.prev + end + if not bl then + syntaxerror("no loop to break") + end +end + +---------------------------------------------------------------------- +-- parse a function call with no returns or an assignment statement +-- * the struct with .prev is used for name searching in lparse.c, +-- so it is retained for now; present in assignment() also +-- * used in stat() +---------------------------------------------------------------------- + +function expr_stat() + -- stat -> expr_stat -> func | assignment + local v = {} + v.v = {} + primaryexp(v.v) + if v.v.k == "VCALL" then -- stat -> func + -- call statement uses no results + else -- stat -> assignment + v.prev = nil + assignment(v) + end +end + +---------------------------------------------------------------------- +-- parse a function statement +-- * used in stat() +---------------------------------------------------------------------- + +function function_stat() + -- stat -> function_stat -> FUNCTION funcname body + local line = line + local v, b = {}, {} + nextt() -- skip FUNCTION + local needself = funcname(v) + body(b, needself, line) +end + +---------------------------------------------------------------------- +-- parse a simple block enclosed by a DO..END pair +-- * used in stat() +---------------------------------------------------------------------- + +function do_stat() + -- stat -> do_stat -> DO block END + local line = line + nextt() -- skip DO + block() + check_match("end", "do", line) +end + +---------------------------------------------------------------------- +-- parse a statement starting with LOCAL +-- * used in stat() +---------------------------------------------------------------------- + +function local_stat() + -- stat -> local_stat -> LOCAL FUNCTION localfunc + -- -> LOCAL localstat + nextt() -- skip LOCAL + if testnext("function") then -- local function? + localfunc() + else + localstat() + end +end + +--[[-------------------------------------------------------------------- +-- main functions, top level parsing functions +-- * accessible functions are: init(lexer), parser() +-- * [entry] -> parser() -> chunk() -> stat() +----------------------------------------------------------------------]] + +---------------------------------------------------------------------- +-- initial parsing for statements, calls '_stat' suffixed functions +-- * used in chunk() +---------------------------------------------------------------------- + +local function stat() + -- stat -> if_stat while_stat do_stat for_stat repeat_stat + -- function_stat local_stat return_stat break_stat + -- expr_stat + line = ln -- may be needed for error messages + local c = tok + local fn = stat_call[c] + -- handles: if while do for repeat function local return break + if fn then + _G[fn]() + -- return or break must be last statement + if c == "return" or c == "break" then return true end + else + expr_stat() + end + return false +end + +---------------------------------------------------------------------- +-- parse a chunk, which consists of a bunch of statements +-- * used in parser(), body(), block(), repeat_stat() +---------------------------------------------------------------------- + +-- this is a forward-referenced local +function chunk() + -- chunk -> { stat [';'] } + local islast = false + while not islast and not block_follow[tok] do + islast = stat() + testnext(";") + end +end + +---------------------------------------------------------------------- +-- performs parsing, returns parsed data structure +---------------------------------------------------------------------- + +function parser() + open_func() + fs.is_vararg = true -- main func. is always vararg + nextt() -- read first token + chunk() + check("") + close_func() + return globalinfo, localinfo +end + +---------------------------------------------------------------------- +-- initialization function +---------------------------------------------------------------------- + +function init(tokorig, seminfoorig, toklnorig) + tpos = 1 -- token position + top_fs = {} -- reset top level function state + ------------------------------------------------------------------ + -- set up grammar-only token tables; impedance-matching... + -- note that constants returned by the lexer is source-level, so + -- for now, fake(!) constant tokens (TK_NUMBER|TK_STRING|TK_LSTRING) + ------------------------------------------------------------------ + local j = 1 + toklist, seminfolist, toklnlist, xreflist = {}, {}, {}, {} + for i = 1, #tokorig do + local tok = tokorig[i] + local yep = true + if tok == "TK_KEYWORD" or tok == "TK_OP" then + tok = seminfoorig[i] + elseif tok == "TK_NAME" then + tok = "" + seminfolist[j] = seminfoorig[i] + elseif tok == "TK_NUMBER" then + tok = "" + seminfolist[j] = 0 -- fake! + elseif tok == "TK_STRING" or tok == "TK_LSTRING" then + tok = "" + seminfolist[j] = "" -- fake! + elseif tok == "TK_EOS" then + tok = "" + else + -- non-grammar tokens; ignore them + yep = false + end + if yep then -- set rest of the information + toklist[j] = tok + toklnlist[j] = toklnorig[i] + xreflist[j] = i + j = j + 1 + end + end--for + ------------------------------------------------------------------ + -- initialize data structures for variable tracking + ------------------------------------------------------------------ + globalinfo, globallookup, localinfo = {}, {}, {} + ilocalinfo, ilocalrefs = {}, {} +end + +return _G diff -r b119b560ca3d -r 2d9fe676e684 minify/optlex.lua --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/minify/optlex.lua Sat Jul 25 03:05:01 2009 +0100 @@ -0,0 +1,832 @@ +--[[-------------------------------------------------------------------- + + optlex.lua: does lexer-based optimizations + This file is part of LuaSrcDiet. + + Copyright (c) 2008 Kein-Hong Man + The COPYRIGHT file describes the conditions + under which this software may be distributed. + + See the ChangeLog for more information. + +----------------------------------------------------------------------]] + +--[[-------------------------------------------------------------------- +-- NOTES: +-- * For more lexer-based optimization ideas, see the TODO items or +-- look at technotes.txt. +-- * TODO: general string delimiter conversion optimizer +-- * TODO: (numbers) warn if overly significant digit +----------------------------------------------------------------------]] + +local base = _G +local string = require "string" +module "optlex" +local match = string.match +local sub = string.sub +local find = string.find +local rep = string.rep +local print + +------------------------------------------------------------------------ +-- variables and data structures +------------------------------------------------------------------------ + +-- error function, can override by setting own function into module +error = base.error + +warn = {} -- table for warning flags + +local stoks, sinfos, stoklns -- source lists + +local is_realtoken = { -- significant (grammar) tokens + TK_KEYWORD = true, + TK_NAME = true, + TK_NUMBER = true, + TK_STRING = true, + TK_LSTRING = true, + TK_OP = true, + TK_EOS = true, +} +local is_faketoken = { -- whitespace (non-grammar) tokens + TK_COMMENT = true, + TK_LCOMMENT = true, + TK_EOL = true, + TK_SPACE = true, +} + +local opt_details -- for extra information + +------------------------------------------------------------------------ +-- true if current token is at the start of a line +-- * skips over deleted tokens via recursion +------------------------------------------------------------------------ + +local function atlinestart(i) + local tok = stoks[i - 1] + if i <= 1 or tok == "TK_EOL" then + return true + elseif tok == "" then + return atlinestart(i - 1) + end + return false +end + +------------------------------------------------------------------------ +-- true if current token is at the end of a line +-- * skips over deleted tokens via recursion +------------------------------------------------------------------------ + +local function atlineend(i) + local tok = stoks[i + 1] + if i >= #stoks or tok == "TK_EOL" or tok == "TK_EOS" then + return true + elseif tok == "" then + return atlineend(i + 1) + end + return false +end + +------------------------------------------------------------------------ +-- counts comment EOLs inside a long comment +-- * in order to keep line numbering, EOLs need to be reinserted +------------------------------------------------------------------------ + +local function commenteols(lcomment) + local sep = #match(lcomment, "^%-%-%[=*%[") + local z = sub(lcomment, sep + 1, -(sep - 1)) -- remove delims + local i, c = 1, 0 + while true do + local p, q, r, s = find(z, "([\r\n])([\r\n]?)", i) + if not p then break end -- if no matches, done + i = p + 1 + c = c + 1 + if #s > 0 and r ~= s then -- skip CRLF or LFCR + i = i + 1 + end + end + return c +end + +------------------------------------------------------------------------ +-- compares two tokens (i, j) and returns the whitespace required +-- * important! see technotes.txt for more information +-- * only two grammar/real tokens are being considered +-- * if "", no separation is needed +-- * if " ", then at least one whitespace (or EOL) is required +------------------------------------------------------------------------ + +local function checkpair(i, j) + local match = match + local t1, t2 = stoks[i], stoks[j] + -------------------------------------------------------------------- + if t1 == "TK_STRING" or t1 == "TK_LSTRING" or + t2 == "TK_STRING" or t2 == "TK_LSTRING" then + return "" + -------------------------------------------------------------------- + elseif t1 == "TK_OP" or t2 == "TK_OP" then + if (t1 == "TK_OP" and (t2 == "TK_KEYWORD" or t2 == "TK_NAME")) or + (t2 == "TK_OP" and (t1 == "TK_KEYWORD" or t1 == "TK_NAME")) then + return "" + end + if t1 == "TK_OP" and t2 == "TK_OP" then + -- for TK_OP/TK_OP pairs, see notes in technotes.txt + local op, op2 = sinfos[i], sinfos[j] + if (match(op, "^%.%.?$") and match(op2, "^%.")) or + (match(op, "^[~=<>]$") and op2 == "=") or + (op == "[" and (op2 == "[" or op2 == "=")) then + return " " + end + return "" + end + -- "TK_OP" + "TK_NUMBER" case + local op = sinfos[i] + if t2 == "TK_OP" then op = sinfos[j] end + if match(op, "^%.%.?%.?$") then + return " " + end + return "" + -------------------------------------------------------------------- + else-- "TK_KEYWORD" | "TK_NAME" | "TK_NUMBER" then + return " " + -------------------------------------------------------------------- + end +end + +------------------------------------------------------------------------ +-- repack tokens, removing deletions caused by optimization process +------------------------------------------------------------------------ + +local function repack_tokens() + local dtoks, dinfos, dtoklns = {}, {}, {} + local j = 1 + for i = 1, #stoks do + local tok = stoks[i] + if tok ~= "" then + dtoks[j], dinfos[j], dtoklns[j] = tok, sinfos[i], stoklns[i] + j = j + 1 + end + end + stoks, sinfos, stoklns = dtoks, dinfos, dtoklns +end + +------------------------------------------------------------------------ +-- number optimization +-- * optimization using string formatting functions is one way of doing +-- this, but here, we consider all cases and handle them separately +-- (possibly an idiotic approach...) +-- * scientific notation being generated is not in canonical form, this +-- may or may not be a bad thing, feedback welcome +-- * note: intermediate portions need to fit into a normal number range +-- * optimizations can be divided based on number patterns: +-- * hexadecimal: +-- (1) no need to remove leading zeros, just skip to (2) +-- (2) convert to integer if size equal or smaller +-- * change if equal size -> lose the 'x' to reduce entropy +-- (3) number is then processed as an integer +-- (4) note: does not make 0[xX] consistent +-- * integer: +-- (1) note: includes anything with trailing ".", ".0", ... +-- (2) remove useless fractional part, if present, e.g. 123.000 +-- (3) remove leading zeros, e.g. 000123 +-- (4) switch to scientific if shorter, e.g. 123000 -> 123e3 +-- * with fraction: +-- (1) split into digits dot digits +-- (2) if no integer portion, take as zero (can omit later) +-- (3) handle degenerate .000 case, after which the fractional part +-- must be non-zero (if zero, it's matched as an integer) +-- (4) remove trailing zeros for fractional portion +-- (5) p.q where p > 0 and q > 0 cannot be shortened any more +-- (6) otherwise p == 0 and the form is .q, e.g. .000123 +-- (7) if scientific shorter, convert, e.g. .000123 -> 123e-6 +-- * scientific: +-- (1) split into (digits dot digits) [eE] ([+-] digits) +-- (2) if significand has ".", shift it out so it becomes an integer +-- (3) if significand is zero, just use zero +-- (4) remove leading zeros for significand +-- (5) shift out trailing zeros for significand +-- (6) examine exponent and determine which format is best: +-- integer, with fraction, scientific +------------------------------------------------------------------------ + +local function do_number(i) + local before = sinfos[i] -- 'before' + local z = before -- working representation + local y -- 'after', if better + -------------------------------------------------------------------- + if match(z, "^0[xX]") then -- hexadecimal number + local v = base.tostring(base.tonumber(z)) + if #v <= #z then + z = v -- change to integer, AND continue + else + return -- no change; stick to hex + end + end + -------------------------------------------------------------------- + if match(z, "^%d+%.?0*$") then -- integer or has useless frac + z = match(z, "^(%d+)%.?0*$") -- int portion only + if z + 0 > 0 then + z = match(z, "^0*([1-9]%d*)$") -- remove leading zeros + local v = #match(z, "0*$") + local nv = base.tostring(v) + if v > #nv + 1 then -- scientific is shorter + z = sub(z, 1, #z - v).."e"..nv + end + y = z + else + y = "0" -- basic zero + end + -------------------------------------------------------------------- + elseif not match(z, "[eE]") then -- number with fraction part + local p, q = match(z, "^(%d*)%.(%d+)$") -- split + if p == "" then p = 0 end -- int part zero + if q + 0 == 0 and p == 0 then + y = "0" -- degenerate .000 case + else + -- now, q > 0 holds and p is a number + local v = #match(q, "0*$") -- remove trailing zeros + if v > 0 then + q = sub(q, 1, #q - v) + end + -- if p > 0, nothing else we can do to simplify p.q case + if p + 0 > 0 then + y = p.."."..q + else + y = "."..q -- tentative, e.g. .000123 + local v = #match(q, "^0*") -- # leading spaces + local w = #q - v -- # significant digits + local nv = base.tostring(#q) + -- e.g. compare 123e-6 versus .000123 + if w + 2 + #nv < 1 + #q then + y = sub(q, -w).."e-"..nv + end + end + end + -------------------------------------------------------------------- + else -- scientific number + local sig, ex = match(z, "^([^eE]+)[eE]([%+%-]?%d+)$") + ex = base.tonumber(ex) + -- if got ".", shift out fractional portion of significand + local p, q = match(sig, "^(%d*)%.(%d*)$") + if p then + ex = ex - #q + sig = p..q + end + if sig + 0 == 0 then + y = "0" -- basic zero + else + local v = #match(sig, "^0*") -- remove leading zeros + sig = sub(sig, v + 1) + v = #match(sig, "0*$") -- shift out trailing zeros + if v > 0 then + sig = sub(sig, 1, #sig - v) + ex = ex + v + end + -- examine exponent and determine which format is best + local nex = base.tostring(ex) + if ex == 0 then -- it's just an integer + y = sig + elseif ex > 0 and (ex <= 1 + #nex) then -- a number + y = sig..rep("0", ex) + elseif ex < 0 and (ex >= -#sig) then -- fraction, e.g. .123 + v = #sig + ex + y = sub(sig, 1, v).."."..sub(sig, v + 1) + elseif ex < 0 and (#nex >= -ex - #sig) then + -- e.g. compare 1234e-5 versus .01234 + -- gives: #sig + 1 + #nex >= 1 + (-ex - #sig) + #sig + -- -> #nex >= -ex - #sig + v = -ex - #sig + y = "."..rep("0", v)..sig + else -- non-canonical scientific representation + y = sig.."e"..ex + end + end--if sig + end + -------------------------------------------------------------------- + if y and y ~= sinfos[i] then + if opt_details then + print(" (line "..stoklns[i]..") "..sinfos[i].." -> "..y) + opt_details = opt_details + 1 + end + sinfos[i] = y + end +end + +------------------------------------------------------------------------ +-- string optimization +-- * note: works on well-formed strings only! +-- * optimizations on characters can be summarized as follows: +-- \a\b\f\n\r\t\v -- no change +-- \\ -- no change +-- \"\' -- depends on delim, other can remove \ +-- \[\] -- remove \ +-- \ -- general escape, remove \ +-- \ -- normalize the EOL only +-- \ddd -- if \a\b\f\n\r\t\v, change to latter +-- if other < ascii 32, keep ddd but zap leading zeros +-- if >= ascii 32, translate it into the literal, then also +-- do escapes for \\,\",\' cases +-- -- no change +-- * switch delimiters if string becomes shorter +------------------------------------------------------------------------ + +local function do_string(I) + local info = sinfos[I] + local delim = sub(info, 1, 1) -- delimiter used + local ndelim = (delim == "'") and '"' or "'" -- opposite " <-> ' + local z = sub(info, 2, -2) -- actual string + local i = 1 + local c_delim, c_ndelim = 0, 0 -- "/' counts + -------------------------------------------------------------------- + while i <= #z do + local c = sub(z, i, i) + ---------------------------------------------------------------- + if c == "\\" then -- escaped stuff + local j = i + 1 + local d = sub(z, j, j) + local p = find("abfnrtv\\\n\r\"\'0123456789", d, 1, true) + ------------------------------------------------------------ + if not p then -- \ -- remove \ + z = sub(z, 1, i - 1)..sub(z, j) + i = i + 1 + ------------------------------------------------------------ + elseif p <= 8 then -- \a\b\f\n\r\t\v\\ + i = i + 2 -- no change + ------------------------------------------------------------ + elseif p <= 10 then -- \ -- normalize EOL + local eol = sub(z, j, j + 1) + if eol == "\r\n" or eol == "\n\r" then + z = sub(z, 1, i).."\n"..sub(z, j + 2) + elseif p == 10 then -- \r case + z = sub(z, 1, i).."\n"..sub(z, j + 1) + end + i = i + 2 + ------------------------------------------------------------ + elseif p <= 12 then -- \"\' -- remove \ for ndelim + if d == delim then + c_delim = c_delim + 1 + i = i + 2 + else + c_ndelim = c_ndelim + 1 + z = sub(z, 1, i - 1)..sub(z, j) + i = i + 1 + end + ------------------------------------------------------------ + else -- \ddd -- various steps + local s = match(z, "^(%d%d?%d?)", j) + j = i + 1 + #s -- skip to location + local cv = s + 0 + local cc = string.char(cv) + local p = find("\a\b\f\n\r\t\v", cc, 1, true) + if p then -- special escapes + s = "\\"..sub("abfnrtv", p, p) + elseif cv < 32 then -- normalized \ddd + s = "\\"..cv + elseif cc == delim then -- \ + s = "\\"..cc + c_delim = c_delim + 1 + elseif cc == "\\" then -- \\ + s = "\\\\" + else -- literal character + s = cc + if cc == ndelim then + c_ndelim = c_ndelim + 1 + end + end + z = sub(z, 1, i - 1)..s..sub(z, j) + i = i + #s + ------------------------------------------------------------ + end--if p + ---------------------------------------------------------------- + else-- c ~= "\\" -- -- no change + i = i + 1 + if c == ndelim then -- count ndelim, for switching delimiters + c_ndelim = c_ndelim + 1 + end + ---------------------------------------------------------------- + end--if c + end--while + -------------------------------------------------------------------- + -- switching delimiters, a long-winded derivation: + -- (1) delim takes 2+2*c_delim bytes, ndelim takes c_ndelim bytes + -- (2) delim becomes c_delim bytes, ndelim becomes 2+2*c_ndelim bytes + -- simplifying the condition (1)>(2) --> c_delim > c_ndelim + if c_delim > c_ndelim then + i = 1 + while i <= #z do + local p, q, r = find(z, "([\'\"])", i) + if not p then break end + if r == delim then -- \ -> + z = sub(z, 1, p - 2)..sub(z, p) + i = p + else-- r == ndelim -- -> \ + z = sub(z, 1, p - 1).."\\"..sub(z, p) + i = p + 2 + end + end--while + delim = ndelim -- actually change delimiters + end + -------------------------------------------------------------------- + z = delim..z..delim + if z ~= sinfos[I] then + if opt_details then + print(" (line "..stoklns[I]..") "..sinfos[I].." -> "..z) + opt_details = opt_details + 1 + end + sinfos[I] = z + end +end + +------------------------------------------------------------------------ +-- long string optimization +-- * note: warning flagged if trailing whitespace found, not trimmed +-- * remove first optional newline +-- * normalize embedded newlines +-- * reduce '=' separators in delimiters if possible +------------------------------------------------------------------------ + +local function do_lstring(I) + local info = sinfos[I] + local delim1 = match(info, "^%[=*%[") -- cut out delimiters + local sep = #delim1 + local delim2 = sub(info, -sep, -1) + local z = sub(info, sep + 1, -(sep + 1)) -- lstring without delims + local y = "" + local i = 1 + -------------------------------------------------------------------- + while true do + local p, q, r, s = find(z, "([\r\n])([\r\n]?)", i) + -- deal with a single line + local ln + if not p then + ln = sub(z, i) + elseif p >= i then + ln = sub(z, i, p - 1) + end + if ln ~= "" then + -- flag a warning if there are trailing spaces, won't optimize! + if match(ln, "%s+$") then + warn.lstring = "trailing whitespace in long string near line "..stoklns[I] + end + y = y..ln + end + if not p then -- done if no more EOLs + break + end + -- deal with line endings, normalize them + i = p + 1 + if p then + if #s > 0 and r ~= s then -- skip CRLF or LFCR + i = i + 1 + end + -- skip first newline, which can be safely deleted + if not(i == 1 and i == p) then + y = y.."\n" + end + end + end--while + -------------------------------------------------------------------- + -- handle possible deletion of one or more '=' separators + if sep >= 3 then + local chk, okay = sep - 1 + -- loop to test ending delimiter with less of '=' down to zero + while chk >= 2 do + local delim = "%]"..rep("=", chk - 2).."%]" + if not match(y, delim) then okay = chk end + chk = chk - 1 + end + if okay then -- change delimiters + sep = rep("=", okay - 2) + delim1, delim2 = "["..sep.."[", "]"..sep.."]" + end + end + -------------------------------------------------------------------- + sinfos[I] = delim1..y..delim2 +end + +------------------------------------------------------------------------ +-- long comment optimization +-- * note: does not remove first optional newline +-- * trim trailing whitespace +-- * normalize embedded newlines +-- * reduce '=' separators in delimiters if possible +------------------------------------------------------------------------ + +local function do_lcomment(I) + local info = sinfos[I] + local delim1 = match(info, "^%-%-%[=*%[") -- cut out delimiters + local sep = #delim1 + local delim2 = sub(info, -sep, -1) + local z = sub(info, sep + 1, -(sep - 1)) -- comment without delims + local y = "" + local i = 1 + -------------------------------------------------------------------- + while true do + local p, q, r, s = find(z, "([\r\n])([\r\n]?)", i) + -- deal with a single line, extract and check trailing whitespace + local ln + if not p then + ln = sub(z, i) + elseif p >= i then + ln = sub(z, i, p - 1) + end + if ln ~= "" then + -- trim trailing whitespace if non-empty line + local ws = match(ln, "%s*$") + if #ws > 0 then ln = sub(ln, 1, -(ws + 1)) end + y = y..ln + end + if not p then -- done if no more EOLs + break + end + -- deal with line endings, normalize them + i = p + 1 + if p then + if #s > 0 and r ~= s then -- skip CRLF or LFCR + i = i + 1 + end + y = y.."\n" + end + end--while + -------------------------------------------------------------------- + -- handle possible deletion of one or more '=' separators + sep = sep - 2 + if sep >= 3 then + local chk, okay = sep - 1 + -- loop to test ending delimiter with less of '=' down to zero + while chk >= 2 do + local delim = "%]"..rep("=", chk - 2).."%]" + if not match(y, delim) then okay = chk end + chk = chk - 1 + end + if okay then -- change delimiters + sep = rep("=", okay - 2) + delim1, delim2 = "--["..sep.."[", "]"..sep.."]" + end + end + -------------------------------------------------------------------- + sinfos[I] = delim1..y..delim2 +end + +------------------------------------------------------------------------ +-- short comment optimization +-- * trim trailing whitespace +------------------------------------------------------------------------ + +local function do_comment(i) + local info = sinfos[i] + local ws = match(info, "%s*$") -- just look from end of string + if #ws > 0 then + info = sub(info, 1, -(ws + 1)) -- trim trailing whitespace + end + sinfos[i] = info +end + +------------------------------------------------------------------------ +-- returns true if string found in long comment +-- * this is a feature to keep copyright or license texts +------------------------------------------------------------------------ + +local function keep_lcomment(opt_keep, info) + if not opt_keep then return false end -- option not set + local delim1 = match(info, "^%-%-%[=*%[") -- cut out delimiters + local sep = #delim1 + local delim2 = sub(info, -sep, -1) + local z = sub(info, sep + 1, -(sep - 1)) -- comment without delims + if find(z, opt_keep, 1, true) then -- try to match + return true + end +end + +------------------------------------------------------------------------ +-- main entry point +-- * currently, lexer processing has 2 passes +-- * processing is done on a line-oriented basis, which is easier to +-- grok due to the next point... +-- * since there are various options that can be enabled or disabled, +-- processing is a little messy or convoluted +------------------------------------------------------------------------ + +function optimize(option, toklist, semlist, toklnlist) + -------------------------------------------------------------------- + -- set option flags + -------------------------------------------------------------------- + local opt_comments = option["opt-comments"] + local opt_whitespace = option["opt-whitespace"] + local opt_emptylines = option["opt-emptylines"] + local opt_eols = option["opt-eols"] + local opt_strings = option["opt-strings"] + local opt_numbers = option["opt-numbers"] + local opt_keep = option.KEEP + opt_details = option.DETAILS and 0 -- upvalues for details display + print = print or base.print + if opt_eols then -- forced settings, otherwise won't work properly + opt_comments = true + opt_whitespace = true + opt_emptylines = true + end + -------------------------------------------------------------------- + -- variable initialization + -------------------------------------------------------------------- + stoks, sinfos, stoklns -- set source lists + = toklist, semlist, toklnlist + local i = 1 -- token position + local tok, info -- current token + local prev -- position of last grammar token + -- on same line (for TK_SPACE stuff) + -------------------------------------------------------------------- + -- changes a token, info pair + -------------------------------------------------------------------- + local function settoken(tok, info, I) + I = I or i + stoks[I] = tok or "" + sinfos[I] = info or "" + end + -------------------------------------------------------------------- + -- processing loop (PASS 1) + -------------------------------------------------------------------- + while true do + tok, info = stoks[i], sinfos[i] + ---------------------------------------------------------------- + local atstart = atlinestart(i) -- set line begin flag + if atstart then prev = nil end + ---------------------------------------------------------------- + if tok == "TK_EOS" then -- end of stream/pass + break + ---------------------------------------------------------------- + elseif tok == "TK_KEYWORD" or -- keywords, identifiers, + tok == "TK_NAME" or -- operators + tok == "TK_OP" then + -- TK_KEYWORD and TK_OP can't be optimized without a big + -- optimization framework; it would be more of an optimizing + -- compiler, not a source code compressor + -- TK_NAME that are locals needs parser to analyze/optimize + prev = i + ---------------------------------------------------------------- + elseif tok == "TK_NUMBER" then -- numbers + if opt_numbers then + do_number(i) -- optimize + end + prev = i + ---------------------------------------------------------------- + elseif tok == "TK_STRING" or -- strings, long strings + tok == "TK_LSTRING" then + if opt_strings then + if tok == "TK_STRING" then + do_string(i) -- optimize + else + do_lstring(i) -- optimize + end + end + prev = i + ---------------------------------------------------------------- + elseif tok == "TK_COMMENT" then -- short comments + if opt_comments then + if i == 1 and sub(info, 1, 1) == "#" then + -- keep shbang comment, trim whitespace + do_comment(i) + else + -- safe to delete, as a TK_EOL (or TK_EOS) always follows + settoken() -- remove entirely + end + elseif opt_whitespace then -- trim whitespace only + do_comment(i) + end + ---------------------------------------------------------------- + elseif tok == "TK_LCOMMENT" then -- long comments + if keep_lcomment(opt_keep, info) then + ------------------------------------------------------------ + -- if --keep, we keep a long comment if is found; + -- this is a feature to keep copyright or license texts + if opt_whitespace then -- trim whitespace only + do_lcomment(i) + end + prev = i + elseif opt_comments then + local eols = commenteols(info) + ------------------------------------------------------------ + -- prepare opt_emptylines case first, if a disposable token + -- follows, current one is safe to dump, else keep a space; + -- it is implied that the operation is safe for '-', because + -- current is a TK_LCOMMENT, and must be separate from a '-' + if is_faketoken[stoks[i + 1]] then + settoken() -- remove entirely + tok = "" + else + settoken("TK_SPACE", " ") + end + ------------------------------------------------------------ + -- if there are embedded EOLs to keep and opt_emptylines is + -- disabled, then switch the token into one or more EOLs + if not opt_emptylines and eols > 0 then + settoken("TK_EOL", rep("\n", eols)) + end + ------------------------------------------------------------ + -- if optimizing whitespaces, force reinterpretation of the + -- token to give a chance for the space to be optimized away + if opt_whitespace and tok ~= "" then + i = i - 1 -- to reinterpret + end + ------------------------------------------------------------ + else -- disabled case + if opt_whitespace then -- trim whitespace only + do_lcomment(i) + end + prev = i + end + ---------------------------------------------------------------- + elseif tok == "TK_EOL" then -- line endings + if atstart and opt_emptylines then + settoken() -- remove entirely + elseif info == "\r\n" or info == "\n\r" then + -- normalize the rest of the EOLs for CRLF/LFCR only + -- (note that TK_LCOMMENT can change into several EOLs) + settoken("TK_EOL", "\n") + end + ---------------------------------------------------------------- + elseif tok == "TK_SPACE" then -- whitespace + if opt_whitespace then + if atstart or atlineend(i) then + -- delete leading and trailing whitespace + settoken() -- remove entirely + else + ------------------------------------------------------------ + -- at this point, since leading whitespace have been removed, + -- there should be a either a real token or a TK_LCOMMENT + -- prior to hitting this whitespace; the TK_LCOMMENT case + -- only happens if opt_comments is disabled; so prev ~= nil + local ptok = stoks[prev] + if ptok == "TK_LCOMMENT" then + -- previous TK_LCOMMENT can abut with anything + settoken() -- remove entirely + else + -- prev must be a grammar token; consecutive TK_SPACE + -- tokens is impossible when optimizing whitespace + local ntok = stoks[i + 1] + if is_faketoken[ntok] then + -- handle special case where a '-' cannot abut with + -- either a short comment or a long comment + if (ntok == "TK_COMMENT" or ntok == "TK_LCOMMENT") and + ptok == "TK_OP" and sinfos[prev] == "-" then + -- keep token + else + settoken() -- remove entirely + end + else--is_realtoken + -- check a pair of grammar tokens, if can abut, then + -- delete space token entirely, otherwise keep one space + local s = checkpair(prev, i + 1) + if s == "" then + settoken() -- remove entirely + else + settoken("TK_SPACE", " ") + end + end + end + ------------------------------------------------------------ + end + end + ---------------------------------------------------------------- + else + error("unidentified token encountered") + end + ---------------------------------------------------------------- + i = i + 1 + end--while + repack_tokens() + -------------------------------------------------------------------- + -- processing loop (PASS 2) + -------------------------------------------------------------------- + if opt_eols then + i = 1 + -- aggressive EOL removal only works with most non-grammar tokens + -- optimized away because it is a rather simple scheme -- basically + -- it just checks 'real' token pairs around EOLs + if stoks[1] == "TK_COMMENT" then + -- first comment still existing must be shbang, skip whole line + i = 3 + end + while true do + tok, info = stoks[i], sinfos[i] + -------------------------------------------------------------- + if tok == "TK_EOS" then -- end of stream/pass + break + -------------------------------------------------------------- + elseif tok == "TK_EOL" then -- consider each TK_EOL + local t1, t2 = stoks[i - 1], stoks[i + 1] + if is_realtoken[t1] and is_realtoken[t2] then -- sanity check + local s = checkpair(i - 1, i + 1) + if s == "" then + settoken() -- remove entirely + end + end + end--if tok + -------------------------------------------------------------- + i = i + 1 + end--while + repack_tokens() + end + -------------------------------------------------------------------- + if opt_details and opt_details > 0 then print() end -- spacing + return stoks, sinfos, stoklns +end diff -r b119b560ca3d -r 2d9fe676e684 minify/optparser.lua --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/minify/optparser.lua Sat Jul 25 03:05:01 2009 +0100 @@ -0,0 +1,442 @@ +--[[-------------------------------------------------------------------- + + optparser.lua: does parser-based optimizations + This file is part of LuaSrcDiet. + + Copyright (c) 2008 Kein-Hong Man + The COPYRIGHT file describes the conditions + under which this software may be distributed. + + See the ChangeLog for more information. + +----------------------------------------------------------------------]] + +--[[-------------------------------------------------------------------- +-- NOTES: +-- * For more parser-based optimization ideas, see the TODO items or +-- look at technotes.txt. +-- * The processing load is quite significant, but since this is an +-- off-line text processor, I believe we can wait a few seconds. +-- * TODO: might process "local a,a,a" wrongly... need tests! +-- * TODO: remove position handling if overlapped locals (rem < 0) +-- needs more study, to check behaviour +-- * TODO: there are probably better ways to do allocation, e.g. by +-- choosing better methods to sort and pick locals... +-- * TODO: we don't need 53*63 two-letter identifiers; we can make +-- do with significantly less depending on how many that are really +-- needed and improve entropy; e.g. 13 needed -> choose 4*4 instead +----------------------------------------------------------------------]] + +local base = _G +local string = require "string" +local table = require "table" +module "optparser" + +---------------------------------------------------------------------- +-- Letter frequencies for reducing symbol entropy (fixed version) +-- * Might help a wee bit when the output file is compressed +-- * See Wikipedia: http://en.wikipedia.org/wiki/Letter_frequencies +-- * We use letter frequencies according to a Linotype keyboard, plus +-- the underscore, and both lower case and upper case letters. +-- * The arrangement below (LC, underscore, %d, UC) is arbitrary. +-- * This is certainly not optimal, but is quick-and-dirty and the +-- process has no significant overhead +---------------------------------------------------------------------- + +local LETTERS = "etaoinshrdlucmfwypvbgkqjxz_ETAOINSHRDLUCMFWYPVBGKQJXZ" +local ALPHANUM = "etaoinshrdlucmfwypvbgkqjxz_0123456789ETAOINSHRDLUCMFWYPVBGKQJXZ" + +-- names or identifiers that must be skipped +-- * the first two lines are for keywords +local SKIP_NAME = {} +for v in string.gmatch([[ +and break do else elseif end false for function if in +local nil not or repeat return then true until while +self]], "%S+") do + SKIP_NAME[v] = true +end + +------------------------------------------------------------------------ +-- variables and data structures +------------------------------------------------------------------------ + +local toklist, seminfolist, -- token lists + globalinfo, localinfo, -- variable information tables + globaluniq, localuniq, -- unique name tables + var_new, -- index of new variable names + varlist -- list of output variables + +---------------------------------------------------------------------- +-- preprocess information table to get lists of unique names +---------------------------------------------------------------------- + +local function preprocess(infotable) + local uniqtable = {} + for i = 1, #infotable do -- enumerate info table + local obj = infotable[i] + local name = obj.name + -------------------------------------------------------------------- + if not uniqtable[name] then -- not found, start an entry + uniqtable[name] = { + decl = 0, token = 0, size = 0, + } + end + -------------------------------------------------------------------- + local uniq = uniqtable[name] -- count declarations, tokens, size + uniq.decl = uniq.decl + 1 + local xref = obj.xref + local xcount = #xref + uniq.token = uniq.token + xcount + uniq.size = uniq.size + xcount * #name + -------------------------------------------------------------------- + if obj.decl then -- if local table, create first,last pairs + obj.id = i + obj.xcount = xcount + if xcount > 1 then -- if ==1, means local never accessed + obj.first = xref[2] + obj.last = xref[xcount] + end + -------------------------------------------------------------------- + else -- if global table, add a back ref + uniq.id = i + end + -------------------------------------------------------------------- + end--for + return uniqtable +end + +---------------------------------------------------------------------- +-- calculate actual symbol frequencies, in order to reduce entropy +-- * this may help further reduce the size of compressed sources +-- * note that since parsing optimizations is put before lexing +-- optimizations, the frequency table is not exact! +-- * yes, this will miss --keep block comments too... +---------------------------------------------------------------------- + +local function recalc_for_entropy(option) + local byte = string.byte + local char = string.char + -- table of token classes to accept in calculating symbol frequency + local ACCEPT = { + TK_KEYWORD = true, TK_NAME = true, TK_NUMBER = true, + TK_STRING = true, TK_LSTRING = true, + } + if not option["opt-comments"] then + ACCEPT.TK_COMMENT = true + ACCEPT.TK_LCOMMENT = true + end + -------------------------------------------------------------------- + -- create a new table and remove any original locals by filtering + -------------------------------------------------------------------- + local filtered = {} + for i = 1, #toklist do + filtered[i] = seminfolist[i] + end + for i = 1, #localinfo do -- enumerate local info table + local obj = localinfo[i] + local xref = obj.xref + for j = 1, obj.xcount do + local p = xref[j] + filtered[p] = "" -- remove locals + end + end + -------------------------------------------------------------------- + local freq = {} -- reset symbol frequency table + for i = 0, 255 do freq[i] = 0 end + for i = 1, #toklist do -- gather symbol frequency + local tok, info = toklist[i], filtered[i] + if ACCEPT[tok] then + for j = 1, #info do + local c = byte(info, j) + freq[c] = freq[c] + 1 + end + end--if + end--for + -------------------------------------------------------------------- + -- function to re-sort symbols according to actual frequencies + -------------------------------------------------------------------- + local function resort(symbols) + local symlist = {} + for i = 1, #symbols do -- prepare table to sort + local c = byte(symbols, i) + symlist[i] = { c = c, freq = freq[c], } + end + table.sort(symlist, -- sort selected symbols + function(v1, v2) + return v1.freq > v2.freq + end + ) + local charlist = {} -- reconstitute the string + for i = 1, #symlist do + charlist[i] = char(symlist[i].c) + end + return table.concat(charlist) + end + -------------------------------------------------------------------- + LETTERS = resort(LETTERS) -- change letter arrangement + ALPHANUM = resort(ALPHANUM) +end + +---------------------------------------------------------------------- +-- returns a string containing a new local variable name to use, and +-- a flag indicating whether it collides with a global variable +-- * trapping keywords and other names like 'self' is done elsewhere +---------------------------------------------------------------------- + +local function new_var_name() + local var + local cletters, calphanum = #LETTERS, #ALPHANUM + local v = var_new + if v < cletters then -- single char + v = v + 1 + var = string.sub(LETTERS, v, v) + else -- longer names + local range, sz = cletters, 1 -- calculate # chars fit + repeat + v = v - range + range = range * calphanum + sz = sz + 1 + until range > v + local n = v % cletters -- left side cycles faster + v = (v - n) / cletters -- do first char first + n = n + 1 + var = string.sub(LETTERS, n, n) + while sz > 1 do + local m = v % calphanum + v = (v - m) / calphanum + m = m + 1 + var = var..string.sub(ALPHANUM, m, m) + sz = sz - 1 + end + end + var_new = var_new + 1 + return var, globaluniq[var] ~= nil +end + +---------------------------------------------------------------------- +-- main entry point +-- * does only local variable optimization for now +---------------------------------------------------------------------- + +function optimize(option, _toklist, _seminfolist, _globalinfo, _localinfo) + -- set tables + toklist, seminfolist, globalinfo, localinfo + = _toklist, _seminfolist, _globalinfo, _localinfo + var_new = 0 -- reset variable name allocator + varlist = {} + ------------------------------------------------------------------ + -- preprocess global/local tables, handle entropy reduction + ------------------------------------------------------------------ + globaluniq = preprocess(globalinfo) + localuniq = preprocess(localinfo) + if option["opt-entropy"] then -- for entropy improvement + recalc_for_entropy(option) + end + ------------------------------------------------------------------ + -- build initial declared object table, then sort according to + -- token count, this might help assign more tokens to more common + -- variable names such as 'e' thus possibly reducing entropy + -- * an object knows its localinfo index via its 'id' field + -- * special handling for "self" special local (parameter) here + ------------------------------------------------------------------ + local object = {} + for i = 1, #localinfo do + object[i] = localinfo[i] + end + table.sort(object, -- sort largest first + function(v1, v2) + return v1.xcount > v2.xcount + end + ) + ------------------------------------------------------------------ + -- the special "self" function parameters must be preserved + -- * the allocator below will never use "self", so it is safe to + -- keep those implicit declarations as-is + ------------------------------------------------------------------ + local temp, j, gotself = {}, 1, false + for i = 1, #object do + local obj = object[i] + if not obj.isself then + temp[j] = obj + j = j + 1 + else + gotself = true + end + end + object = temp + ------------------------------------------------------------------ + -- a simple first-come first-served heuristic name allocator, + -- note that this is in no way optimal... + -- * each object is a local variable declaration plus existence + -- * the aim is to assign short names to as many tokens as possible, + -- so the following tries to maximize name reuse + -- * note that we preserve sort order + ------------------------------------------------------------------ + local nobject = #object + while nobject > 0 do + local varname, gcollide + repeat + varname, gcollide = new_var_name() -- collect a variable name + until not SKIP_NAME[varname] -- skip all special names + varlist[#varlist + 1] = varname -- keep a list + local oleft = nobject + ------------------------------------------------------------------ + -- if variable name collides with an existing global, the name + -- cannot be used by a local when the name is accessed as a global + -- during which the local is alive (between 'act' to 'rem'), so + -- we drop objects that collides with the corresponding global + ------------------------------------------------------------------ + if gcollide then + -- find the xref table of the global + local gref = globalinfo[globaluniq[varname].id].xref + local ngref = #gref + -- enumerate for all current objects; all are valid at this point + for i = 1, nobject do + local obj = object[i] + local act, rem = obj.act, obj.rem -- 'live' range of local + -- if rem < 0, it is a -id to a local that had the same name + -- so follow rem to extend it; does this make sense? + while rem < 0 do + rem = localinfo[-rem].rem + end + local drop + for j = 1, ngref do + local p = gref[j] + if p >= act and p <= rem then drop = true end -- in range? + end + if drop then + obj.skip = true + oleft = oleft - 1 + end + end--for + end--if gcollide + ------------------------------------------------------------------ + -- now the first unassigned local (since it's sorted) will be the + -- one with the most tokens to rename, so we set this one and then + -- eliminate all others that collides, then any locals that left + -- can then reuse the same variable name; this is repeated until + -- all local declaration that can use this name is assigned + -- * the criteria for local-local reuse/collision is: + -- A is the local with a name already assigned + -- B is the unassigned local under consideration + -- => anytime A is accessed, it cannot be when B is 'live' + -- => to speed up things, we have first/last accesses noted + ------------------------------------------------------------------ + while oleft > 0 do + local i = 1 + while object[i].skip do -- scan for first object + i = i + 1 + end + ------------------------------------------------------------------ + -- first object is free for assignment of the variable name + -- [first,last] gives the access range for collision checking + ------------------------------------------------------------------ + oleft = oleft - 1 + local obja = object[i] + i = i + 1 + obja.newname = varname + obja.skip = true + obja.done = true + local first, last = obja.first, obja.last + local xref = obja.xref + ------------------------------------------------------------------ + -- then, scan all the rest and drop those colliding + -- if A was never accessed then it'll never collide with anything + -- otherwise trivial skip if: + -- * B was activated after A's last access (last < act) + -- * B was removed before A's first access (first > rem) + -- if not, see detailed skip below... + ------------------------------------------------------------------ + if first and oleft > 0 then -- must have at least 1 access + local scanleft = oleft + while scanleft > 0 do + while object[i].skip do -- next valid object + i = i + 1 + end + scanleft = scanleft - 1 + local objb = object[i] + i = i + 1 + local act, rem = objb.act, objb.rem -- live range of B + -- if rem < 0, extend range of rem thru' following local + while rem < 0 do + rem = localinfo[-rem].rem + end + -------------------------------------------------------- + if not(last < act or first > rem) then -- possible collision + -------------------------------------------------------- + -- B is activated later than A or at the same statement, + -- this means for no collision, A cannot be accessed when B + -- is alive, since B overrides A (or is a peer) + -------------------------------------------------------- + if act >= obja.act then + for j = 1, obja.xcount do -- ... then check every access + local p = xref[j] + if p >= act and p <= rem then -- A accessed when B live! + oleft = oleft - 1 + objb.skip = true + break + end + end--for + -------------------------------------------------------- + -- A is activated later than B, this means for no collision, + -- A's access is okay since it overrides B, but B's last + -- access need to be earlier than A's activation time + -------------------------------------------------------- + else + if objb.last and objb.last >= obja.act then + oleft = oleft - 1 + objb.skip = true + end + end + end + -------------------------------------------------------- + if oleft == 0 then break end + end + end--if first + ------------------------------------------------------------------ + end--while + ------------------------------------------------------------------ + -- after assigning all possible locals to one variable name, the + -- unassigned locals/objects have the skip field reset and the table + -- is compacted, to hopefully reduce iteration time + ------------------------------------------------------------------ + local temp, j = {}, 1 + for i = 1, nobject do + local obj = object[i] + if not obj.done then + obj.skip = false + temp[j] = obj + j = j + 1 + end + end + object = temp -- new compacted object table + nobject = #object -- objects left to process + ------------------------------------------------------------------ + end--while + ------------------------------------------------------------------ + -- after assigning all locals with new variable names, we can + -- patch in the new names, and reprocess to get 'after' stats + ------------------------------------------------------------------ + for i = 1, #localinfo do -- enumerate all locals + local obj = localinfo[i] + local xref = obj.xref + if obj.newname then -- if got new name, patch it in + for j = 1, obj.xcount do + local p = xref[j] -- xrefs indexes the token list + seminfolist[p] = obj.newname + end + obj.name, obj.oldname -- adjust names + = obj.newname, obj.name + else + obj.oldname = obj.name -- for cases like 'self' + end + end + ------------------------------------------------------------------ + -- deal with statistics output + ------------------------------------------------------------------ + if gotself then -- add 'self' to end of list + varlist[#varlist + 1] = "self" + end + local afteruniq = preprocess(localinfo) + ------------------------------------------------------------------ +end diff -r b119b560ca3d -r 2d9fe676e684 minify/squish.minify.lua --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/minify/squish.minify.lua Sat Jul 25 03:05:01 2009 +0100 @@ -0,0 +1,78 @@ +local optlex = require "optlex" +local optparser = require "optparser" +local llex = require "llex" +local lparser = require "lparser" + +local minify_defaults = { + none = {}; + default = { "comments", "whitespace", "emptylines", "numbers", "locals" }; + basic = { "comments", "whitespace", "emptylines" }; + maximum = { "comments", "whitespace", "emptylines", "eols", "strings", "numbers", "locals", "entropy" }; + } +minify_defaults.full = minify_defaults.maximum; + +for _, opt in ipairs(minify_defaults[opts.minify_level or "default"] or {}) do + opts["minify_"..opt] = true; +end + +local option = { + ["opt-locals"] = opts.minify_locals; + ["opt-comments"] = opts.minify_comments; + ["opt-entropy"] = opts.minify_entropy; + ["opt-whitespace"] = opts.minify_whitespace; + ["opt-emptylines"] = opts.minify_emptylines; + ["opt-eols"] = opts.minify_eols; + ["opt-strings"] = opts.minify_strings; + ["opt-numbers"] = opts.minify_numbers; + } + +local function die(msg) + print("LuaSrcDiet: "..msg); os.exit() +end + +local function load_file(fname) + local INF = io.open(fname, "rb") + if not INF then die("cannot open \""..fname.."\" for reading") end + local dat = INF:read("*a") + if not dat then die("cannot read from \""..fname.."\"") end + INF:close() + return dat +end + +local function save_file(fname, dat) + local OUTF = io.open(fname, "wb") + if not OUTF then die("cannot open \""..fname.."\" for writing") end + local status = OUTF:write(dat) + if not status then die("cannot write to \""..fname.."\"") end + OUTF:close() +end + + +function minify(srcfl, destfl) + local z = load_file(srcfl) + llex.init(z) + llex.llex() + local toklist, seminfolist, toklnlist + = llex.tok, llex.seminfo, llex.tokln + if option["opt-locals"] then + optparser.print = print -- hack + lparser.init(toklist, seminfolist, toklnlist) + local globalinfo, localinfo = lparser.parser() + optparser.optimize(option, toklist, seminfolist, globalinfo, localinfo) + end + optlex.print = print -- hack + toklist, seminfolist, toklnlist + = optlex.optimize(option, toklist, seminfolist, toklnlist) + local dat = table.concat(seminfolist) + -- depending on options selected, embedded EOLs in long strings and + -- long comments may not have been translated to \n, tack a warning + if string.find(dat, "\r\n", 1, 1) or + string.find(dat, "\n\r", 1, 1) then + optlex.warn.mixedeol = true + end + -- save optimized source stream to output file + save_file(destfl, dat) +end + +print_info("Minifying "..out_fn.."..."); +minify(out_fn, out_fn);