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

augment evaluate to extract within objects (#1425)

Browse Source 
- 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
This commit is contained in:
Alex Lam S.L
2017-01-26 19:14:18 +08:00
committed by Richard van Velzen
parent 48284844a4
commit 0d7d4918eb
6 changed files with 729 additions and 14 deletions
Download Patch File Download Diff File Expand all files Collapse all files

17
lib/scope.js
View File

@@ -184,6 +184,17 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options){
var func = null;
var globals = self.globals = new Dictionary();
var tw = new TreeWalker(function(node, descend){
function isModified(node, level) {
var parent = tw.parent(level);
if (parent instanceof AST_Unary && (parent.operator === "++" || parent.operator === "--")
|| parent instanceof AST_Assign && parent.left === node
|| parent instanceof AST_Call && parent.expression === node) {
return true;
} else if (parent instanceof AST_PropAccess && parent.expression === node) {
return isModified(parent, level + 1);
}
}
if (node instanceof AST_Lambda) {
var prev_func = func;
func = node;
@@ -197,8 +208,7 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options){
}
if (node instanceof AST_SymbolRef) {
var name = node.name;
var parent = tw.parent();
if (name == "eval" && parent instanceof AST_Call) {
if (name == "eval" && tw.parent() instanceof AST_Call) {
for (var s = node.scope; s && !s.uses_eval; s = s.parent_scope) {
s.uses_eval = true;
}
@@ -220,8 +230,7 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options){
sym = g;
}
node.thedef = sym;
if (parent instanceof AST_Unary && (parent.operator === "++" || parent.operator === "--")
|| parent instanceof AST_Assign && parent.left === node) {
if (isModified(node, 0)) {
sym.modified = true;
}
node.reference();