catch identifier is mangled correctly for ES5 standards-compliant JS engines by default.
Unconditionally use the ie8 if/do-while workaround whether or not --screw-ie8 is enabled.
To support non-standard ie8 javascript use: uglifyjs --support-ie8
- Partially reverting 91cdb93e57 and eaf3911c31 and reimplement
- Add generators support for objects and classes
- Only classes can have static methods so restrict use of it
Special thanks to @rvanvelzen and @kzc for reviewing this patch and
providing constructive feedback over and over again.
- Make let, const, and class symbols be declared in a block scope.
- Piggy back on existing catch symbol implementation to get block-aware mangling working
- Make sure unused block-scoped declarations can be dropped
- Don't eliminate a block if it has a block-scoped declaration
- Remove silly empty anonymous blocks left over from drop_unused
- AST_Toplevel now gets to call drop_unused too, since block-scoped variables aren't global!
- Don't consider block declarations global
It's now available during tree walking, i.e. walker.has_directive("use
asm"), rather than as part of the scope. It's thus no longer necessary
to call `figure_out_scope` before codegen. Added special bits in the
code generator to overcome the fact that it doesn't inherit from
TreeWalker.
Fix#861
The effect of not mangling it was visible only with --screw-ie8 (otherwise
the names would be mangled exactly because they leaked into the parent
scope).
Previously:
Without `--screw-ie`, UglifyJS would always leak names of function
expressions into the containing scope, as if they were function
declarations. That was to emulate IE<9 behavior. Code relying on this
IE bug would continue to work properly after mangling, although it would
only work in IE (since other engines don't share the bug). Sometimes
this broke legitimage code (see #153 and #155).
With `--screw-ie` the names would not be leaked into the current scope,
working properly in legit cases; but still it broke legit code when
running in IE<9 (see #24).
Currently:
Regardless of the `--screw-ie` setting, the names will not be leaked.
Code relying on the IE bug will not work properly after mangling.
<evil laughter here>
Without `--screw-ie`: a hack has been added to the mangler to avoid
using the same name for a function expression and some other variable in
the same scope. This keeps legit code working, at the (negligible,
indeed) cost of one more identifier.
With `--screw-ie` you allow the mangler to name function expressions
with the same identifier as another variable in scope. After mangling
code might break in IE<9.
Oh man, the commit message is longer than the patch.
Fix#153, #155
For now the implication is that UglifyJS will not leak a function
expression's name in the surrounding scope (IE < 9 does that).
(ref. mishoo/UglifyJS#485)
