Alex Lam S.L
1f0333e9f1
stay safe with constants in IE8- ( #1547 )
...
- `undefined` etc. can be redefined at top-level for IE8-, so disable related optimisations
- fixed `--support-ie8` catch mangle bug
2017-03-05 12:51:11 +08:00
Alex Lam S.L
78d1bb92d4
fix a corner case in #1530 ( #1552 )
2017-03-05 12:12:59 +08:00
kzc
ce54c9ccee
disallow collapse_vars constant replacement in for-in statements ( #1543 )
2017-03-04 02:39:54 +08:00
Alex Lam S.L
07accd2fbb
process code with implicit return statement ( #1522 )
...
Bookmarklet for instance implicitedly assumes a "completion value" without using `return`.
The `expression` option now supports such use cases.
Optimisations on IIFEs also enhanced.
fixes #354
fixes #543
fixes #625
fixes #628
fixes #640
closes #1293
2017-03-03 18:13:07 +08:00
Alex Lam S.L
18059cc94f
compress numerical expressions ( #1513 )
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safe operations
- `a === b` => `a == b`
- `a + -b` => `a - b`
- `-a + b` => `b - a`
- `a+ +b` => `+b+a`
associative operations
(bit-wise operations are safe, otherwise `unsafe_math`)
- `a + (b + c)` => `(a + b) + c`
- `(n + 2) + 3` => `5 + n`
- `(2 * n) * 3` => `6 * n`
- `(a | 1) | (2 | d)` => `(3 | a) | b`
fixes #412
2017-03-03 18:04:32 +08:00
Alex Lam S.L
b5e0e8c203
facilitate fix for #1531 ( #1542 )
2017-03-03 07:12:24 +08:00
Alex Lam S.L
17b81350d4
fix chained assignment with unused ( #1540 )
...
When #1450 optimises `a=b=42`, it stops after the first variable even if both are unused.
fixes #1539
2017-03-03 04:45:20 +08:00
kzc
4d63d4f5b3
collapse_vars should not replace constant in for-in init section ( #1538 )
...
fixes #1537
2017-03-03 03:51:15 +08:00
Alex Lam S.L
70d72ad806
properly cover all cases of for-in loop variables ( #1536 )
2017-03-03 02:39:57 +08:00
Alex Lam S.L
fe9227a41b
fix reference marking in for-in loops ( #1535 )
...
fixes #1533
2017-03-03 00:56:06 +08:00
Alex Lam S.L
b49e142a26
disable do{...}while(false) optimisation ( #1534 )
...
- fails to handle `break` in body
fixes #1532
2017-03-03 00:54:41 +08:00
kzc
ee3b39b909
optimize trivial IIFEs returning constants ( #1530 )
2017-03-02 15:11:40 +08:00
Alex Lam S.L
9699ffb1af
trim unused invocation parameters ( #1526 )
2017-03-02 11:33:59 +08:00
Alex Lam S.L
fdc9b9413b
minor improvement to string optimisation ( #1514 )
...
- "" + "a" => "a"
- "" + a + "b" => a + "b"
- "a" + "" => "a" (improving on #45 )
2017-03-02 11:31:39 +08:00
Alex Lam S.L
7aa69117e1
fix corner cases in reduce_vars ( #1524 )
...
Avoid variable substitution in the following cases:
- use of variable before declaration
- declaration within conditional code blocks
- declaration within loop body
fixes #1518
fixes #1525
2017-03-02 00:20:53 +08:00
Alex Lam S.L
c2334baa48
fix crash on missing props to string_template() ( #1523 )
...
Patched up `make_node()` without `orig`.
There may be other cases where `start` could be missing, so make it print "undefined" instead of crashing.
fixes #1518
2017-03-01 15:25:26 +08:00
Alex Lam S.L
f5cbe19b75
invert reduce_vars tracking flag ( #1519 )
...
Modules like webpack and grunt-contrib-uglify still uses `ast.transform(compressor)` before `Compressor.compress(ast)` was introduced.
Workaround this compatibility issue by deactivating `reduce_vars` in such case.
Also fix use case with omitted `options` when calling `Compressor()`.
fixes #1516
2017-03-01 04:12:10 +08:00
Alex Lam S.L
b34fa11a13
fix evaluate on object getter & setter ( #1515 )
2017-03-01 02:03:47 +08:00
Alex Lam S.L
4365a51237
temporarily disables reduce_vars ( #1517 )
...
... as we investigate #1516
2017-03-01 00:25:43 +08:00
Alex Lam S.L
858e6c78a4
warn & drop #__PURE__ iff IIFE is dropped ( #1511 )
...
- consolidate `side-effects` optimisations
- improve string `+` optimisation
- enhance literal & `conditionals` optimisations
2017-02-28 02:25:44 +08:00
Alex Lam S.L
13be50a4a9
faster tree transversal ( #1462 )
...
- convert `[].forEach()` to for-loops
2017-02-26 05:58:26 +08:00
Alex Lam S.L
16cd5d57a5
consolidate evaluate & reduce_vars ( #1505 )
...
- improve marking efficiency
- apply smarter `const` replacement to `var`
fixes #1501
2017-02-26 00:40:33 +08:00
alexlamsl
4e49302916
enable collapse_vars & reduce_vars by default
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- fix corner cases in `const` optimisation
- deprecate `/*@const*/`
fixes #1497
closes #1498
2017-02-24 01:46:57 +08:00
kzc
1e51586996
Support marking a call as pure
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A function call or IIFE with an immediately preceding comment
containing `@__PURE__` or `#__PURE__` is deemed to be a
side-effect-free pure function call and can potentially be
dropped.
Depends on `side_effects` option.
`[#@]__PURE__` hint will be removed from comment when pure
call is dropped.
fixes #1261
closes #1448
2017-02-21 14:24:18 +08:00
alexlamsl
26fbeece1c
fix pure_funcs & improve side_effects
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- only drops side-effect-free arguments
- drop side-effect-free parts with discarded value from `AST_Seq` & `AST_SimpleStatement`
closes #1494
2017-02-21 13:31:59 +08:00
alexlamsl
ec64acd2c8
introduce unsafe_proto
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- `Array.prototype.slice` => `[].slice`
closes #1491
2017-02-21 13:29:58 +08:00
alexlamsl
e275148998
enhance global_defs
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- support arrays, objects & AST_Node
- support `"a.b":1` on both cli & API
- emit warning if variable is modified
- override top-level variables
fixes #1416
closes #1198
closes #1469
2017-02-21 13:29:58 +08:00
alexlamsl
974247c8c0
evaluate AST_SymbolRef as parameter
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fix invalid boolean conversion now exposed in `make_node_from_constant()`
closes #1477
2017-02-21 13:29:58 +08:00
alexlamsl
a0f4fd390a
improve reduce_vars and fix a bug
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- update modified flag between compress() passes
- support IIFE arguments
- fix corner case with multiple definitions
closes #1473
2017-02-21 13:29:58 +08:00
alexlamsl
b8b133d91a
improve keep_fargs & keep_fnames
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- utilise in_use_ids instead of unreferenced()
- drop_unused now up-to-date for subsequent passes
closes #1476
2017-02-21 13:29:58 +08:00
kzc
6ffbecb72b
smarter const replacement taking name length into account
...
closes #1459
2017-02-21 13:29:58 +08:00
alexlamsl
f0ff6189be
clean up negate_iife
...
- remove extra tree scanning phase for `negate_iife`
- `negate_iife` now only deals with the narrowest form, i.e. IIFE sitting directly under `AST_SimpleStatement`
- `booleans`, `conditionals` etc. will now take care the rest via more accurate accounting
- `a(); void b();` => `a(); b();`
fixes #1288
closes #1451
2017-02-21 13:29:58 +08:00
alexlamsl
6b3c49e458
improve string concatenation
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shuffle associative operations to minimise parentheses and aid other uglification efforts
closes #1454
2017-02-21 13:29:57 +08:00
alexlamsl
f584ca8d07
-c sequences=N suboptimal at N expression cutoff
...
N = 2:
a;
b;
c;
d;
was:
a, b;
c;
d;
now:
a, b;
c, d;
fixes #1455
closes #1457
2017-02-21 13:29:57 +08:00
alexlamsl
ae4db00991
tweak do-while loops
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- `do{...}while(false)` => `{...}`
- clean up `AST_While` logic
closes #1452
2017-02-21 13:29:57 +08:00
alexlamsl
100307ab31
fixes & improvements to [].join()
...
fixes
- [a].join() => "" + a
- ["a", , "b"].join() => "a,,b"
- ["a", null, "b"].join() => "a,,b"
- ["a", undefined, "b"].join() => "a,,b"
improvements
- ["a", "b"].join(null) => "anullb"
- ["a", "b"].join(undefined) => "a,b"
- [a + "b", c].join("") => a + "b" + c
closes #1453
2017-02-21 13:29:57 +08:00
alexlamsl
148047fbbf
drop unused: toplevel, assign-only
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- assign statement does not count towards variable usage by default
- only works with assignments on the same scope level as declaration
- can be disabled with `unused` set to "keep_assign"
- `toplevel` to drop unused top-level variables and/or functions
- `top_retain` to whitelist top-level exceptions
closes #1450
2017-02-21 13:29:57 +08:00
kzc
d11dca3cf9
fix stray else in compress with conditionals=false
...
closes #1449
2017-02-21 13:29:57 +08:00
alexlamsl
e5badb9541
enable typeof "undefined" for general use
...
move out of unsafe, guard corner case with screw_id8 instead
closes #1446
2017-02-18 19:01:42 +08:00
alexlamsl
11676f9d72
fix crash in unsafe replacement of undefined
...
remove extraneous call to AST_SymbolRef.reference()
closes #1443
2017-02-18 18:58:23 +08:00
Anthony Van de Gejuchte
dd31d12a91
Improve optimizing function() { if(c){return foo} bar();}
...
closes #1437
2017-02-18 18:56:18 +08:00
Alex Lam S.L
0610c020b1
optimise binary operands with evaluate() ( #1427 )
...
- remove call to evaluate() in is_constant() and let nested optimize() does its job instead
- reject RegExp in is_constant() and remove special case logic under collapse_vars
- operands to conditionals optimisation are now always evaluate()-ed
- throw error in constant_value() instead of returning undefined to catch possible bugs, similar to make_node_from_constant()
- optimise binary boolean operators under `evaluate` instead of `conditionals`
2017-01-26 12:16:50 +01:00
Alex Lam S.L
0d7d4918eb
augment evaluate to extract within objects ( #1425 )
...
- gated by `unsafe`
- replaces previous optimisation specific to String.length
- "123"[0] => 1
- [1, 2, 3][0] => 1
- [1, 2, 3].length => 3
- does not apply to objects with overridden prototype functions
2017-01-26 12:14:18 +01:00
alexlamsl
48284844a4
add missing LHS cases which global_defs should avoid
2017-01-19 21:06:28 +01:00
Anthony Van de Gejuchte
79b98a9fe8
Do not overwrite options.comments + cleanup
2016-11-29 20:24:08 +01:00
kzc
fc9804b909
Fix (typeof side_effect()) in boolean context
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Fixes #1289 with suggestion by @rvanvelzen
2016-10-06 13:50:11 +02:00
alexlamsl
4761d07e0b
Optimize unmodified variables
2016-10-01 11:36:11 +02:00
kzc
25fc02743a
Account for side effects in string + expr optimization
2016-09-01 09:24:56 -04:00
kzc
0bd8053524
implement optimization: (x = 2 * x) ---> (x *= 2)
2016-08-30 08:43:02 -04:00
Richard van Velzen
8430123e9d
Fix negate_iife transform to return a correct tree for nested IIFEs
...
Fix for #1256 , partially reverts d854523783
2016-08-17 11:55:59 +02:00