JoBoEVD/UglifyJS
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

fix corner case in side_effects (#4326)

Browse Source 
fixes #4325
This commit is contained in:
Alex Lam S.L
2020-11-29 02:05:48 +00:00
committed by GitHub
parent f045e2b460
commit 9d34f8428b
5 changed files with 60 additions and 17 deletions
Download Patch File Download Diff File Expand all files Collapse all files

33
lib/compress.js
View File

@@ -5592,20 +5592,10 @@ merge(Compressor.prototype, {
} else if (node instanceof AST_ForIn) {
if (!drop_vars || !compressor.option("loops")) return;
if (!is_empty(node.body)) return;
var sym = node.init;
if (sym instanceof AST_Definitions) {
sym = sym.definitions[0].name;
} else while (sym instanceof AST_PropAccess) {
sym = sym.expression.tail_node();
}
if (sym instanceof AST_Destructured) return;
var sym = get_init_symbol(node);
if (!sym) return;
var def = sym.definition();
if (!def) return;
if (def.id in in_use_ids) return;
if (def.scope !== self) {
var d = self.find_variable(sym);
if ((d && d.redefined() || d) === def) return;
}
log(sym, "Dropping unused loop variable {name}");
if (for_ins[def.id] === node) delete for_ins[def.id];
var body = [];
@@ -5705,6 +5695,16 @@ merge(Compressor.prototype, {
return rhs.right;
}
function get_init_symbol(for_in) {
var init = for_in.init;
if (init instanceof AST_Definitions) {
init = init.definitions[0].name;
return init instanceof AST_SymbolDeclaration && init;
}
while (init instanceof AST_PropAccess) init = init.expression.tail_node();
if (init instanceof AST_SymbolRef) return init;
}
function scan_ref_scoped(node, descend, init) {
if (node instanceof AST_Assign && node.left instanceof AST_SymbolRef) {
var def = node.left.definition();
@@ -5748,8 +5748,14 @@ merge(Compressor.prototype, {
}
if (!drop_vars || !compressor.option("loops")) return;
if (!is_empty(node.body)) return;
if (node.init instanceof AST_Destructured) return;
if (node.init.has_side_effects(compressor)) return;
var sym = get_init_symbol(node);
if (!sym) return;
var def = sym.definition();
if (def.scope !== self) {
var d = self.find_variable(sym);
if ((d && d.redefined() || d) === def) return;
}
node.object.walk(tw);
return true;
}
@@ -6259,6 +6265,7 @@ merge(Compressor.prototype, {
});
// always shallow clone to ensure stripping of negated IIFEs
self = self.clone();
self.expression = exp.clone();
}
if (self instanceof AST_New) {
var fn = exp;