Commit Graph

390 Commits

Author SHA1 Message Date
Richard van Velzen
f4d36a58c2 Fix #569
When no arguments are given to `new Function()`, it should be treated as
a regular anonymous function (http://es5.github.io/#x15.3.2.1)
2015-01-04 13:37:59 +01:00
Richard van Velzen
c75f5a1fd8 Fix #597
NaN and Infinity were replaced in the output generation, instead of
during compression. This could lead to results where `1/0` was inserted
without parens leading to invalid output.

The nodes are replaced in the compression step now, and the output
generation returns their regular names. This should not be a problem,
since they're already only constructed from the original name.
2014-12-31 12:23:00 +01:00
Mihai Bazon
01d19b4b52 Referencing a global is assumed to have side effects.
Close #550
2014-09-28 11:18:25 +03:00
Tal Ater
fb0ec720a4 Compress conditions that have side effects using sequences 2014-09-04 02:57:49 +03:00
Tal Ater
885835a655 Compress conditional assignments where all possible outcomes are equivalant and condition has no side effects 2014-09-02 23:30:25 +03:00
Mihai Bazon
4c64554808 Turn foo.new into foo["new"] when not --screw-ie8. Fix #534 2014-08-26 10:11:01 +03:00
Mihai Bazon
548beeb6b1 Prevent error for Function(""). Close #538 2014-08-20 09:16:34 +03:00
Dan Wolff
8511e80f48 Evaluate "foo".length ==> 3 2014-07-01 11:06:51 +03:00
Artemy Tregubenko
524a8a42a4 added @ngInject support for inline functions 2014-05-11 14:01:08 +02:00
Mihai Bazon
ef2ef07cbd Add option keep_fargs.
By default it's `false`.  Pass `true` if you need to keep unused function
arguments.

Close #188.
2014-02-08 12:33:56 +02:00
Matt Basta
ac0086a745 Simplify nested conditionals if possible 2014-02-06 12:39:13 -08:00
Mihai Bazon
5344b7dab8 Fix if_return dropping the alternative. Close #413 2014-01-31 10:44:13 +02:00
Mihai Bazon
c3087dd179 Better process_for_angular before other statement reductions. #395 2014-01-08 11:39:24 +02:00
Mihai Bazon
2c305af478 Support @ngInject with angular compressor option. Close #395. 2014-01-08 11:28:32 +02:00
Mihai Bazon
2c88eb6fbe doh. 2014-01-07 12:54:14 +02:00
Mihai Bazon
27142df4f5 minor: exp["10"] => exp[10] 2014-01-07 12:48:21 +02:00
Mihai Bazon
b521b4b926 Conditional/call optimization
foo ? bar(x) : bar(y)  ==>  bar(foo ? x : y)
2013-12-29 10:31:30 +02:00
Mihai Bazon
5a083a938d Optimize seq,void 0. Close #377.
(x, void 0)    => void x
    (x, undefined) => void x
2013-12-22 11:36:45 +02:00
Mihai Bazon
dc5f70eab5 Add drop_console option to the compressor 2013-12-10 19:44:41 +02:00
Mihai Bazon
df8c5623af minor 2013-12-10 19:39:03 +02:00
Mihai Bazon
d2190c2bf3 Properly scope catch identifier when --screw-ie8
Fix #344
2013-11-28 16:43:30 +02:00
Mihai Bazon
50b8d7272c Fix faulty compression
`String(x + 5)` is not always the same as `x + "5"`.  Overlooked that. :-(

Close #350
2013-11-20 21:13:16 +02:00
Mihai Bazon
7d11b96f48 Only descend twice after drop_unused if it's the same node type.
Fix #345
2013-11-08 11:57:17 +02:00
Mihai Bazon
eab99a1c3d Better fix for #343
We can in fact lift sequences, but only if the operation is assignment and
the left-hand side has no side effects nor property access -- that should
guarantee that whatever we place before it cannot affect the sense of the
assignment.

Dropped contrived test case (too hard to support it now), added a more
meaningful one.
2013-11-06 10:48:48 +02:00
Mihai Bazon
f4919e3a25 Do not lift sequence from right-hand side of binary operation. Fix #343 2013-11-06 10:18:28 +02:00
Mihai Bazon
b70670b69f Fix regression after e4c5302406
`x * (y * z)` ==> `x * y * z` -- the better place to do this is in the
compressor rather than codegen.
2013-10-30 10:45:58 +02:00
Mihai Bazon
9dd97605bc indentation 2013-10-30 10:44:50 +02:00
Richard van Velzen
785c6064cc Disallow reversal where lhs has higher or equal precedence
Fixes #267
2013-10-29 21:37:36 +01:00
Richard van Velzen
e2daee9a65 Fix RHS concat (raised in #330)
When attempting to concat the left-side of the rhs, make sure the rhs is
a string.
2013-10-26 18:44:52 +02:00
Richard van Velzen
1a5a4bd631 Fix #269
Shorten most primitives where possible. Also optimize some edge cases.
2013-10-24 11:08:33 +02:00
Richard van Velzen
7055af8221 Fix #280
The `init` of the `ForStatement` is not a `BlockStatement` before it was
descended. The descend has to happen first, and *then* the actual
checks.
2013-10-23 22:26:04 +02:00
Mihai Bazon
63d04fff69 Revert #3a81f60 for now
(with it some tests break and it can generate invalid output, see issue #44)
2013-10-22 21:50:55 +03:00
Mihai Bazon
3fa9265ce4 wrap up 2013-10-09 22:15:43 +03:00
Mihai Bazon
3a81f60982 Don't drop_unused before compression.
Fix #280, #282
2013-10-09 19:15:09 +03:00
Mihai Bazon
f2348dd98b Rename clean_getters to pure_getters; add pure_funcs. 2013-10-04 13:17:25 +03:00
Mihai Bazon
8cc86fee60 add clean_getters compressor option (default false)
allows one to specify if `foo.bar` is considered to have side effects.
2013-10-02 19:38:01 +03:00
Mihai Bazon
88fb83aa81 minor optimization
unlikely to help in hand-written code:

    (something() ? foo : bar) == foo  ==>  something()
2013-10-02 15:31:31 +03:00
Mihai Bazon
95b4507c02 Fix error in the output minifying Function("return this")() 2013-09-30 11:49:29 +03:00
Mihai Bazon
afdaeba37d More attempts to determine when addition is associative
Somebody hit me with bug reports on this. :)

Refs #300
2013-09-22 15:26:10 +03:00
Mihai Bazon
037199bfe2 Actually let's move away those monsters from the evaluate function
ev() should do a single thing — evaluate constant expressions.  if that's
not possible, just return the original node.  it's not the best place for
partial evaluation there, instead doing it in the compress functions.
2013-09-22 15:00:42 +03:00
Mihai Bazon
583fac0a0f More dirty handling of [ ... ].join() in unsafe mode
Close #300
2013-09-22 13:14:42 +03:00
Dan Wolff
e8158279ff Evaluate [...].join() if possible: minor bugfix
Follow-up to 78e98d2.
2013-09-22 11:34:30 +03:00
Mihai Bazon
78e98d2611 When unsafe is set, evaluate [...].join() if possible
Close #298
2013-09-19 18:20:45 +03:00
Dan Wolff
8d14efe818 Concatenate strings also on the right-hand side of an expression that cannot be evaluated. Fix #126
E.g. converts:
  a+'Hello'+'World'
to
  a+'HelloWorld'
2013-09-19 13:03:03 +03:00
Mihai Bazon
85b527ba3d Disallow continue referring to a non-IterationStatement. Fix #287
Simplifies handling of labels (their definition/references can be easily
figured out at parse time, no need to do it in `figure_out_scope`).
2013-09-02 19:36:16 +03:00
Mihai Bazon
ed80b4a534 Move support for negate_iife in the compressor, rather than code generator
(the code generator doesn't maintain enough context to know whether
the return value is important or discarded)

Fixes #272
2013-08-20 17:45:52 +03:00
Michael Ficarra
d9ad3c7cbf fixes #259: don't unnecessarily quote object properties when --screw-ie8 2013-08-18 19:45:06 -05:00
Mihai Bazon
4c4dc2137c Don't drop unused setter argument.
Fix #257
2013-08-07 12:04:58 +03:00
Mihai Bazon
964d5b9aa4 Don't pretend to evaluate lambdas
Fix #255
2013-08-04 21:44:17 +03:00
Mihai Bazon
41c627379c Reverting "added option for dropping unused params"
Revert "added option for dropping unused params"

(turns out we already had the `unused` option for this.)

This reverts commit e54df2226f.
2013-07-25 18:08:36 +03:00
Dusan Bartos
e54df2226f added option for dropping unused params 2013-07-25 17:37:47 +03:00
Mihai Bazon
02a84385a0 Don't swap binary ops when "use asm" is in effect.
Refs #167
2013-06-07 12:52:09 +03:00
Mihai Bazon
caa8896a8a Only compress code in new Function if all arguments are strings. 2013-05-14 18:36:31 +03:00
Mihai Bazon
f64539fb76 Compress code passed to new Function if it's a constant.
Only for `--unsafe`.

Close #203
2013-05-14 10:47:06 +03:00
Mihai Bazon
d56ebd7d7b Fix a["1_1"]
Close #204
2013-05-14 10:42:34 +03:00
Mihai Bazon
a6ed2c84ac Better fix for equality of typeof ... against "undefined" 2013-05-08 16:22:48 +03:00
Justin Lau
a1958aad56 Fixed typeof undefined optimization and updated related test case to
accomodates the sort behaviour changes made in commit
mishoo/UglifyJS2@aebafad41e.
Signed-off-by: Justin Lau <justin@tclau.com>
2013-05-08 16:22:48 +03:00
Justin Lau
9af2bbffde Fixed dot properties not optimizing unicode identifiers. Signed-off-by: Justin Lau <justin@tclau.com> 2013-05-07 14:20:19 +03:00
Justin Lau
1e3bc0caa0 Fixed dot property issue with invlid identifier names.
Signed-off-by: Justin Lau <justin@tclau.com>
2013-05-05 22:27:43 +08:00
Michael Ficarra
5af144522a fixes #189: use dotted member access when --screw-ie8 option given 2013-04-20 15:11:05 -05:00
Roman Bataev
4b818056cf Fix typeof evaluation for regex and function 2013-04-03 22:34:38 -04:00
Mihai Bazon
e4b078cff7 Disable unsafe by default
Close #147
2013-03-11 00:04:31 +02:00
Mihai Bazon
aebafad41e Fix reordering comparisons
Close #143
2013-03-04 10:06:01 +02:00
Mihai Bazon
dac6efb43d Drop last default: if it's the last branch and empty
Close #141
2013-03-01 13:12:03 +02:00
Mihai Bazon
8880f4824c Compress boolean constants after evaluation
Close #137
2013-03-01 10:26:06 +02:00
Mihai Bazon
3a591c43fe Fix compressing do {...} while (false)
It's not safe to transform it to {...} because the body might contain
`break`.  The solution could be more elaborate (detect if body contains
`break`) but I don't think it's worth the trouble.

Close #129
2013-02-19 18:12:19 +02:00
Mihai Bazon
f36e4e9a78 Give up evaluating (unary-prefix '-' 0)
Close #117

------

    JS, WHY YOU SUCK SO BADLY? ;-(
2013-02-06 11:51:09 +02:00
Mihai Bazon
9e8ba27dcd Fix handling of constants
Close #113
2013-02-06 11:15:31 +02:00
Richard Gibson
522566ea80 Fix #105: property comparison to undefined is not always safe 2013-01-23 23:52:04 -05:00
Mihai Bazon
f0909bdc8f Handle String() with no arguments.
Fix #91
2013-01-17 11:01:38 +02:00
Mihai Bazon
31c4a37e37 Optimize new Array(1, 2, 3) → [1, 2, 3]
Close #74
2012-12-21 21:04:35 +02:00
Mihai Bazon
16430acc1f small improvement on merging assignments into hoisted vars 2012-12-05 13:14:49 +02:00
Mihai Bazon
320c110b33 When hoisting variables, try to merge in assignments that follow. 2012-12-05 12:30:25 +02:00
Mihai Bazon
5cc90db7d0 Don't messup compressor stack while optimizing Switch
Fix #59
2012-11-30 11:16:09 +02:00
Mihai Bazon
4f555e2232 fix for https://github.com/mishoo/UglifyJS/issues/474 2012-11-23 10:20:00 +02:00
Mihai Bazon
0d3fd2ef30 retain (1,eval) as is when it's the expression of an AST_Call
otherwise we change the meaning of eval from global to lexical.
2012-11-17 12:05:31 +02:00
Mihai Bazon
bdfcbf496b better solution for the last test in constant switch folding 2012-11-14 12:21:43 +02:00
Mihai Bazon
dba8da4800 optimize constant switch blocks
ref. mishoo/UglifyJS#441
2012-11-14 12:06:07 +02:00
Mihai Bazon
60c0f40250 Merge branch 'optimize_concat' of https://github.com/rvanvelzen/UglifyJS2 into rvanvelzen-optimize_concat 2012-11-13 14:38:55 +02:00
Mihai Bazon
e02771a5f2 don't change order in binary expressions if both operands have side effects 2012-11-13 14:32:07 +02:00
Richard van Velzen
f96f796f71 Add simple optimization for empty-string concats.
ref. #43
2012-11-12 15:41:03 +01:00
Mihai Bazon
53355bdb24 fix invalid AST produced by dropping unused variable
close #44
2012-11-12 13:23:57 +02:00
Dan Wolff
b49230ab8d convert x.toString() to ""+x instead of x+""
In some places this can save one byte in whitespace, e.g. after return.
Example:

function f(arg) {
        // return""+arg - no space between return and ""
        return arg.toString();
}
2012-11-11 15:53:34 +02:00
Mihai Bazon
1e5e13ed81 AST_LabelRef no longer inherits from AST_SymbolRef 2012-11-08 15:39:14 +02:00
Mihai Bazon
1a5fd3e052 optimization for if/break as first statement in a loop body
for(...; x; ...) if (y) break; → for(...; x&&!y; ...);

similarly for `while` and some combinations (i.e. the `break` appears in the
`else` clause, etc.)
2012-11-08 11:43:14 +02:00
Mihai Bazon
ffccb233e5 convert while into for 2012-11-05 16:01:20 +02:00
Mihai Bazon
fba0c1aafe minor 2012-11-05 16:01:09 +02:00
Mihai Bazon
774f2ded94 minor optimization
for `==` or `!=` against a constant, prefer to display the constant first.
should help a bit after gzip, i.e.:

    typeof foo=="undefined"
    ^^^^^^    ^^^^^^^^^^^^^

vs:

    "undefined"==typeof foo
    ^^^^^^^^^^^^^^^^^^^     (longer sequence that could repeat)

idea stolen from closure.
2012-11-05 13:13:06 +02:00
Mihai Bazon
8413787efc use a Dictionary object instead of plain object for hashes
to mitigate the `__proto__` issue

related to #30
2012-11-02 10:58:45 +02:00
Mihai Bazon
cf409800be it's safe to negate expression in !EXP only in boolean context
#kendo
2012-11-01 15:49:05 +02:00
Mihai Bazon
18270dd9f3 added unsafe_comps for negating <= with >
since it has the potential to break code, let's keep it disabled by default
2012-11-01 15:14:56 +02:00
Mihai Bazon
d4c25c571b fix compressing UnaryPrefix
only try negating the expression if the operator is `!`

#kendo
2012-11-01 13:35:08 +02:00
Mihai Bazon
abe0ebbf02 don't move expressions containing the binary in operator into the for initializer
(opera can't parse it)

close #25
2012-10-30 14:50:47 +02:00
Mihai Bazon
70fd2b1f33 fix for if (...) return; else return ...;
(it was assumed that the first `return` always contains a value)

close #22
2012-10-24 09:33:32 +03:00
Mihai Bazon
30faaf13ed more sequence optimizations (lift some sequences above binary/unary expressions so that we can avoid parens) 2012-10-22 11:58:06 +03:00
Mihai Bazon
fc8314e810 minor fix for dropping unused definitions.
function f(x, y) {
        var g = function() { return h() };
        var h = function() { return g() };
        return x + y;
    }

now compresses to `function f(x, y) { return x + y }`
2012-10-19 12:57:29 +03:00
Mihai Bazon
afb7faa6fa more optimizations for some break/continue cases 2012-10-18 15:14:57 +03:00
Mihai Bazon
253bd8559b more small optimizations
(unlikely to help for hand-written code)
2012-10-17 21:57:08 +03:00
Mihai Bazon
6a099fba66 define aborts on AST_If: true if both branches abort 2012-10-17 16:17:14 +03:00
Mihai Bazon
a21f3c6cdd employ a better parser for command-line arguments
to support passing commas in strings in for example:

    uglifyjs2 -cd TEST="'a,b'" <<EOF
    console.log(TEST);
    EOF

    → console.log("a,b")

close #14
2012-10-17 15:56:45 +03:00
Mihai Bazon
fcc0229087 drop unused function arguments
also add test for "drop_unused" (the last one fails for now)
2012-10-13 15:04:44 +03:00
Mihai Bazon
851b48e4a3 fix compressing benchmark.js (it tried to evaluate a statement)
the following code in benchmark.js triggered the issue:

    support.decompilation = Function(
      'return (' + (function(x) { return { 'x': '' + (1 + x) + '', 'y': 0 }; }) + ')'
    )()(0).x === '1';

technically that could be resolved into a constant expression, but seems
it's being used here for browser bugs detection :-\
2012-10-13 12:57:10 +03:00
Mihai Bazon
1b6f8d463f remove the $self hack
operations are destructive anyway, so there's no point to clone the nodes in
the transformer.  speed++
2012-10-12 11:07:35 +03:00
Mihai Bazon
172aa7a93c cleanup
- use prototype-less objects where feasible (minor speed improvement)
- get rid of HOP
2012-10-11 11:07:42 +03:00
Mihai Bazon
c5ecbfc756 drop unused variable 2012-10-10 11:27:06 +03:00
Mihai Bazon
86182afa7f minor 2012-10-09 22:56:59 +03:00
Mihai Bazon
a84d07e312 add AST_Infinity node 2012-10-09 18:35:53 +03:00
Mihai Bazon
1b0aab2ce9 added $propdoc to AST nodes and some cleanups
hopefully we can make the AST documentation self-generating
2012-10-09 18:20:39 +03:00
Mihai Bazon
9ead49641d minor AST cleanup (AST_BlockStatement may inherit from AST_Block) 2012-10-09 13:59:17 +03:00
Mihai Bazon
2c025f23db fix detecting symbols in use 2012-10-09 13:13:55 +03:00
Mihai Bazon
093a9031dc eliminate redundant directives in the same scope 2012-10-08 12:53:17 +03:00
Mihai Bazon
4a2b91220a minor 2012-10-05 20:24:56 +03:00
Mihai Bazon
a1e0885930 replace (function(){ ...no side effects ... })() with undefined. 2012-10-05 16:51:16 +03:00
Mihai Bazon
682a58a1f5 removed some unused variables 2012-10-04 08:49:18 +03:00
Mihai Bazon
11863d6f9a more cleanup (dropped AST_SwitchBlock) 2012-10-03 15:52:31 +03:00
Mihai Bazon
3412498795 AST cleanup (dropped AST_StatementBase) 2012-10-03 15:41:11 +03:00
Mihai Bazon
c11de17e99 added option for side-effect-free statements, fix test 2012-10-03 13:08:03 +03:00
Mihai Bazon
e0f5075e45 fix endless loop in tests 2012-10-03 12:49:47 +03:00
Mihai Bazon
0678ae2076 fix for a = !b && !c && !d && !e → a=!(b||c||d||e) 2012-10-03 11:34:05 +03:00
Mihai Bazon
378ed17809 disable hoist_vars by default and change comparations to comparisons 2012-10-03 11:27:05 +03:00
Mihai Bazon
dde5b22b5e support defines 2012-10-02 13:20:07 +03:00
Mihai Bazon
e1098b04a7 "use strict"; 2012-10-02 12:45:58 +03:00
Mihai Bazon
211792757c more constant folding (for names defined with const) 2012-10-02 12:45:17 +03:00
Mihai Bazon
ff696cd7bc drop more unused names 2012-10-02 12:02:33 +03:00
Mihai Bazon
9e5dd81f1e a shy attempt to obey width in the beautifier; added bracketize option to always print brackets around if/do/while/for statements; export more options via the CLI 2012-10-02 11:22:38 +03:00
Mihai Bazon
13278c6649 removed the "squeeze" method (it's now effectively "transform") 2012-09-26 19:52:32 +03:00
Mihai Bazon
15d58f5917 some speedup and more savings from unused vars that have side effects in initialization 2012-09-26 19:05:49 +03:00
Mihai Bazon
78be8f5296 compressor successfully moved to TreeTransformer 2012-09-26 14:27:01 +03:00
Mihai Bazon
a24e7ee976 checkpoint (refactoring, WIP) 2012-09-26 12:16:16 +03:00
Mihai Bazon
242dd10131 more cleanups 2012-09-25 20:39:15 +03:00
Mihai Bazon
9321d418bc moving code around (refactoring, WIP) 2012-09-25 15:59:27 +03:00
Mihai Bazon
4201577dd7 started some refactoring (WIP) -- moving squeezer to TreeTransformer 2012-09-25 15:15:47 +03:00
Mihai Bazon
e836e2ae5f minor 2012-09-25 12:48:36 +03:00
Mihai Bazon
ea6d1ea701 it's not safe to assume that property access is side-effect-free
(getters/setters + various browser bugs will trigger side effects; also, an
exception is thrown when the expression is undefined)
2012-09-25 10:32:14 +03:00
Mihai Bazon
368ac8f93c some boolean cleanup 2012-09-25 10:31:03 +03:00
Mihai Bazon
a83b28503f properly drop mutually-referring declarations that are not otherwise
referenced and have no side effects
2012-09-23 12:47:34 +03:00
Mihai Bazon
76d88b59dc tree transformer api (WIP) 2012-09-22 19:41:09 +03:00
Mihai Bazon
ec7f895b54 log filename in parse errors / compressor warnings 2012-09-21 14:44:25 +03:00
Mihai Bazon
c4f8c2103f more on detecting side effects 2012-09-21 11:23:44 +03:00
Mihai Bazon
e8da72d304 drop unused variables 2012-09-19 12:27:38 +03:00
Mihai Bazon
3da0ac4897 support for directives 2012-09-18 13:21:09 +03:00
Mihai Bazon
21968285e8 added AST_NaN (output as 0/0) 2012-09-18 10:53:46 +03:00
Mihai Bazon
d91613b4a8 only do the typeof x == "undefined" optimization if x is a symbol reference and it's declared in scope, or x is not a symbol reference. 2012-09-17 20:02:57 +03:00
Mihai Bazon
ee669ba878 moved typeof foo == "undefined" ==> foo === undefined under --unsafe
because 43fd45154b (commitcomment-1864505)
2012-09-17 18:49:52 +03:00
Mihai Bazon
e370e3b5a4 fix .undeclared (it's now a function) 2012-09-17 15:06:06 +03:00
Mihai Bazon
6ad414ef28 minor 2012-09-17 14:33:36 +03:00
Mihai Bazon
92e22c460d possible optimization for AST_Undefined
if undefined is defined, ;-), we replace AST_Undefined nodes to a reference
to the "undefined" variable; in turn the mangler will compress it to a
single letter; this helps at least on jQuery.
2012-09-17 12:27:32 +03:00
Mihai Bazon
14481de0e9 empty block to empty statement: {} ==> ; 2012-09-17 12:03:02 +03:00
Mihai Bazon
07f1d56f69 more smallish optimizations 2012-09-17 11:50:35 +03:00
Mihai Bazon
5e60a60b3b try negating AST_Binary 2012-09-17 11:16:44 +03:00
Mihai Bazon
5d781ec6f8 some cleanup 2012-09-16 18:10:54 +03:00
Mihai Bazon
0f418d654e more sequencesizing (WIP) 2012-09-16 16:29:17 +03:00
Mihai Bazon
21c34a1792 drop unused function 2012-09-16 15:46:47 +03:00
Mihai Bazon
7b6a402916 rewrite handle_if_return
optimizations of if/return/continue seem to be even better now
2012-09-16 15:46:20 +03:00
Mihai Bazon
397bf56d25 other small optimization:
if (foo) continue;
...body...

==>

if (!foo) { ...body ... }

Only when the parent block is the target loop of the `continue` statement.
2012-09-15 16:10:35 +03:00
Mihai Bazon
86c14d0988 join_vars:
var XXX;
for (var YYY; ...)

==>

for (var XXX,YYY; ...)
2012-09-15 10:54:59 +03:00
Mihai Bazon
43fd45154b compress typeof x == "undefined" to x === undefined, which further gets
shortened to x === void 0 (or x === [][0] in unsafe mode)
2012-09-14 19:56:59 +03:00
Mihai Bazon
50d1670e42 minor
when unsafe, compress undefined as [][0]
2012-09-14 19:04:18 +03:00
Mihai Bazon
5e83e7ec17 adding an imaginary "return undefined" can sometimes help
function f() {
  if (foo) return x();
  if (!bar) return y();
}

==>

function f() {
  return foo ? x() : bar ? void 0 : y();
}
2012-09-14 16:26:30 +03:00
Mihai Bazon
924aa58060 more optimizations that v1 does and some cleanups
- a = a + x ==> a+=x
- joining consecutive var statements (hoisting is not always desirable)
- x == false ==> x == 0, x != true ==> x != 1
- x, x ==> x; x = exp(), x ==> x = exp()
- discarding useless break-s
2012-09-14 15:36:38 +03:00
Mihai Bazon
d72c1d1293 few more optimizations:
- do multiple passes in tighten_body if it was changed
- transform if (foo) return x; return y; ==> return foo?x:y
- don't optimize !0 as true (use best_of after evaluation of constant expr)

With hoist_vars off we now beat UglifyJS v1 on jQuery-1.8.1
2012-09-13 15:20:57 +03:00
Mihai Bazon
f5027ec1fc minor 2012-09-12 16:29:20 +03:00
Mihai Bazon
a132841fb9 more AST_If optimizations 2012-09-12 16:10:03 +03:00
Mihai Bazon
2b1e4628e0 side effect fixes and small optimization for gzip
prefer to always use > and >= operators (idea from Closure)
2012-09-12 13:41:46 +03:00
Mihai Bazon
2b4093ba83 fixed run-tests and an issue about reversing the condition in AST_If 2012-09-12 13:00:13 +03:00
Mihai Bazon
9a629abe00 minor 2012-09-11 18:37:08 +03:00
Mihai Bazon
da407d46c6 checkpoint
- discard statements with no side effects (unsafe? could be)
- safer hoist_vars (needs some revamping of scope/mangling)
2012-09-11 13:15:55 +03:00
Mihai Bazon
1579c0fb97 hoist_vars is pretty bad, it seems. cancelled it for now. 2012-09-10 22:40:18 +03:00
Mihai Bazon
a41e6cfabb more progress on the compressor (WIP) 2012-09-10 16:37:05 +03:00
Mihai Bazon
1c8ba35844 minor 2012-09-08 22:51:59 +03:00
Mihai Bazon
048d6906ae fix bug (forgot arg name) 2012-09-07 16:02:08 +03:00
Mihai Bazon
919b2733ab always keep declarations found in unreachable code
a few more tests and some cleanups.
2012-09-07 15:18:32 +03:00
Mihai Bazon
b77574ea1c fixed tests (need to drop the toplevel block in "expected" if it's a single statement) 2012-09-07 11:22:01 +03:00
Mihai Bazon
9bb1a84d6b don't duplicate argument names 2012-09-05 18:19:30 +03:00
Mihai Bazon
0503513dcc support for hoisting declarations
and finally it seems we beat v1 in terms of compression
2012-09-05 13:43:34 +03:00
Mihai Bazon
8633b0073f cleaned up usage of AST_BlockStatement
The following nodes were instances of AST_BlockStatement: AST_Scope,
AST_SwitchBlock, AST_SwitchBranch.  Also, AST_Try, AST_Catch, AST_Finally
were having a body instanceof AST_BlockStatement.

Overloading the meaning of AST_BlockStatement this way turned out to be a
mess; we now have an AST_Block class that is the base class for things
having a block of statements (might or might not be bracketed).  The
`this.body` of AST_Scope, AST_Try, AST_Catch, AST_Finally is now an array of
statements (as they inherit from AST_Block).

Avoiding calling superclass's _walk function in walkers (turns out we walked
a node multiple times).
2012-09-05 11:39:43 +03:00
Mihai Bazon
1b5183dd5e checkpoint 2012-09-04 15:36:14 +03:00
Mihai Bazon
376667a818 more fiddling with boolean expressions, etc.
optimize away while(false), and transform while(true) ==> for(;;).

UNSAFE:

some expressions are optimized away when we're in boolean context and can
determine that the value will always be true or false.  For example:

    x() || true ==> always `true` in boolean context
    x() && false ==> always `false` in boolean context

It's not technically correct to drop these expressions since we drop the
function call too (that might have side effects); on the other hand, I can't
see any legitimate use for such expressions and they might simply indicate a
bug (we do warn about it).
2012-09-04 13:20:28 +03:00
Mihai Bazon
86cfb5be86 boolean and if/exit optimizations 2012-09-03 23:49:57 +03:00
Mihai Bazon
e5f1cec6aa minor 2012-09-03 23:25:30 +03:00
Mihai Bazon
37eecc16a4 more optimizations for ifs/conditionals
(XXX: should add tests before anything else)
2012-09-03 19:38:45 +03:00
Mihai Bazon
f03138daa8 resolve constant expressions 2012-09-03 15:47:15 +03:00
Mihai Bazon
6d0db4ce14 an AST_If is too a StatementWithBody 2012-09-03 12:11:44 +03:00
Mihai Bazon
d7c1dc6c05 a LabeledStatement should be in fact a StatementWithBody
This fixes output for:

    if (foo) {
        moo: if (bar) {
            break moo;
        }
    } else {
        baz();
    }

(the labeled statement must be outputted inside brackets)
2012-09-03 12:05:10 +03:00
Mihai Bazon
58a3b5e93f update (c) years 2012-08-27 11:01:41 +03:00
Mihai Bazon
4437e7af19 fix compressing a,b; return c; into return a,b,c; 2012-08-27 11:00:22 +03:00
Mihai Bazon
95b18e54a4 added license 2012-08-22 21:28:59 +03:00
Mihai Bazon
159a6f048c wrote more of the compressor and added some tests 2012-08-22 15:21:58 +03:00
Mihai Bazon
1b839eb35b hint that brackets may be required in AST_BlockStatement 2012-08-21 19:16:05 +03:00
Mihai Bazon
ffe58a9961 cleaned up some mess and started the actual compressor 2012-08-21 16:14:43 +03:00