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fix escape analysis on AST_PropAccess (#2636)

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This commit is contained in:
Alex Lam S.L
2017-12-24 00:36:46 +08:00
committed by GitHub
parent edb4e3bd52
commit c07ea17c01
2 changed files with 76 additions and 50 deletions
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95
lib/compress.js
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@@ -418,29 +418,27 @@ merge(Compressor.prototype, {
} }
} }
function mark_escaped(tw, d, scope, node, value, level) { function mark_escaped(tw, d, scope, node, value, level, depth) {
var parent = tw.parent(level); var parent = tw.parent(level);
if (value) { if (value && value.is_constant()) return;
if (value.is_constant()) return;
if (level > 0 && value.is_constant_expression(scope)) return;
}
if (parent instanceof AST_Assign && parent.operator == "=" && node === parent.right if (parent instanceof AST_Assign && parent.operator == "=" && node === parent.right
|| parent instanceof AST_Call && node !== parent.expression || parent instanceof AST_Call && node !== parent.expression
|| parent instanceof AST_Exit && node === parent.value && node.scope !== d.scope || parent instanceof AST_Exit && node === parent.value && node.scope !== d.scope
|| parent instanceof AST_VarDef && node === parent.value) { || parent instanceof AST_VarDef && node === parent.value) {
d.escaped = true; if (depth > 1 && !(value && value.is_constant_expression(scope))) depth = 1;
if (!d.escaped || d.escaped > depth) d.escaped = depth;
return; return;
} else if (parent instanceof AST_Array } else if (parent instanceof AST_Array
|| parent instanceof AST_Binary && lazy_op(parent.operator) || parent instanceof AST_Binary && lazy_op(parent.operator)
|| parent instanceof AST_Conditional && node !== parent.condition || parent instanceof AST_Conditional && node !== parent.condition
|| parent instanceof AST_Sequence && node === parent.tail_node()) { || parent instanceof AST_Sequence && node === parent.tail_node()) {
mark_escaped(tw, d, scope, parent, parent, level + 1); mark_escaped(tw, d, scope, parent, parent, level + 1, depth);
} else if (parent instanceof AST_ObjectKeyVal && node === parent.value) { } else if (parent instanceof AST_ObjectKeyVal && node === parent.value) {
var obj = tw.parent(level + 1); var obj = tw.parent(level + 1);
mark_escaped(tw, d, scope, obj, obj, level + 2); mark_escaped(tw, d, scope, obj, obj, level + 2, depth);
} else if (parent instanceof AST_PropAccess && node === parent.expression) { } else if (parent instanceof AST_PropAccess && node === parent.expression) {
value = read_property(value, parent.property); value = read_property(value, parent.property);
mark_escaped(tw, d, scope, parent, value, level + 1); mark_escaped(tw, d, scope, parent, value, level + 1, depth + 1);
if (value) return; if (value) return;
} }
if (level == 0) d.direct_access = true; if (level == 0) d.direct_access = true;
@@ -637,7 +635,7 @@ merge(Compressor.prototype, {
} }
} }
} }
mark_escaped(tw, d, this.scope, this, value, 0); mark_escaped(tw, d, this.scope, this, value, 0, 1);
}); });
def(AST_Toplevel, function(tw, descend, compressor) { def(AST_Toplevel, function(tw, descend, compressor) {
this.globals.each(function(def) { this.globals.each(function(def) {
@@ -1909,7 +1907,7 @@ merge(Compressor.prototype, {
// descendant of AST_Node. // descendant of AST_Node.
AST_Node.DEFMETHOD("evaluate", function(compressor){ AST_Node.DEFMETHOD("evaluate", function(compressor){
if (!compressor.option("evaluate")) return this; if (!compressor.option("evaluate")) return this;
var val = this._eval(compressor); var val = this._eval(compressor, 1);
return !val || val instanceof RegExp || typeof val != "object" ? val : this; return !val || val instanceof RegExp || typeof val != "object" ? val : this;
}); });
var unaryPrefix = makePredicate("! ~ - + void"); var unaryPrefix = makePredicate("! ~ - + void");
@@ -1928,22 +1926,17 @@ merge(Compressor.prototype, {
throw new Error(string_template("Cannot evaluate a statement [{file}:{line},{col}]", this.start)); throw new Error(string_template("Cannot evaluate a statement [{file}:{line},{col}]", this.start));
}); });
def(AST_Lambda, return_this); def(AST_Lambda, return_this);
function ev(node, compressor) {
if (!compressor) throw new Error("Compressor must be passed");
return node._eval(compressor);
};
def(AST_Node, return_this); def(AST_Node, return_this);
def(AST_Constant, function(){ def(AST_Constant, function(){
return this.getValue(); return this.getValue();
}); });
def(AST_Array, function(compressor){ def(AST_Array, function(compressor, depth) {
if (compressor.option("unsafe")) { if (compressor.option("unsafe")) {
var elements = []; var elements = [];
for (var i = 0, len = this.elements.length; i < len; i++) { for (var i = 0, len = this.elements.length; i < len; i++) {
var element = this.elements[i]; var element = this.elements[i];
if (element instanceof AST_Function) continue; if (element instanceof AST_Function) continue;
var value = ev(element, compressor); var value = element._eval(compressor, depth);
if (element === value) return this; if (element === value) return this;
elements.push(value); elements.push(value);
} }
@@ -1951,7 +1944,7 @@ merge(Compressor.prototype, {
} }
return this; return this;
}); });
def(AST_Object, function(compressor){ def(AST_Object, function(compressor, depth) {
if (compressor.option("unsafe")) { if (compressor.option("unsafe")) {
var val = {}; var val = {};
for (var i = 0, len = this.properties.length; i < len; i++) { for (var i = 0, len = this.properties.length; i < len; i++) {
@@ -1960,21 +1953,21 @@ merge(Compressor.prototype, {
if (key instanceof AST_Symbol) { if (key instanceof AST_Symbol) {
key = key.name; key = key.name;
} else if (key instanceof AST_Node) { } else if (key instanceof AST_Node) {
key = ev(key, compressor); key = key._eval(compressor, depth);
if (key === prop.key) return this; if (key === prop.key) return this;
} }
if (typeof Object.prototype[key] === 'function') { if (typeof Object.prototype[key] === 'function') {
return this; return this;
} }
if (prop.value instanceof AST_Function) continue; if (prop.value instanceof AST_Function) continue;
val[key] = ev(prop.value, compressor); val[key] = prop.value._eval(compressor, depth);
if (val[key] === prop.value) return this; if (val[key] === prop.value) return this;
} }
return val; return val;
} }
return this; return this;
}); });
def(AST_UnaryPrefix, function(compressor){ def(AST_UnaryPrefix, function(compressor, depth) {
var e = this.expression; var e = this.expression;
// Function would be evaluated to an array and so typeof would // Function would be evaluated to an array and so typeof would
// incorrectly return 'object'. Hence making is a special case. // incorrectly return 'object'. Hence making is a special case.
@@ -1985,7 +1978,7 @@ merge(Compressor.prototype, {
&& e.fixed_value() instanceof AST_Lambda)) { && e.fixed_value() instanceof AST_Lambda)) {
return typeof function(){}; return typeof function(){};
} }
e = ev(e, compressor); e = e._eval(compressor, depth);
if (e === this.expression) return this; if (e === this.expression) return this;
switch (this.operator) { switch (this.operator) {
case "!": return !e; case "!": return !e;
@@ -2001,10 +1994,10 @@ merge(Compressor.prototype, {
} }
return this; return this;
}); });
def(AST_Binary, function(compressor){ def(AST_Binary, function(compressor, depth) {
var left = ev(this.left, compressor); var left = this.left._eval(compressor, depth);
if (left === this.left) return this; if (left === this.left) return this;
var right = ev(this.right, compressor); var right = this.right._eval(compressor, depth);
if (right === this.right) return this; if (right === this.right) return this;
var result; var result;
switch (this.operator) { switch (this.operator) {
@@ -2038,30 +2031,32 @@ merge(Compressor.prototype, {
} }
return result; return result;
}); });
def(AST_Conditional, function(compressor){ def(AST_Conditional, function(compressor, depth) {
var condition = ev(this.condition, compressor); var condition = this.condition._eval(compressor, depth);
if (condition === this.condition) return this; if (condition === this.condition) return this;
var node = condition ? this.consequent : this.alternative; var node = condition ? this.consequent : this.alternative;
var value = ev(node, compressor); var value = node._eval(compressor, depth);
return value === node ? this : value; return value === node ? this : value;
}); });
def(AST_SymbolRef, function(compressor){ def(AST_SymbolRef, function(compressor, depth) {
var fixed = this.fixed_value(); var fixed = this.fixed_value();
if (!fixed) return this; if (!fixed) return this;
this._eval = return_this; var value;
var value = ev(fixed, compressor); if (HOP(fixed, "_eval")) {
if (value === fixed) { value = fixed._eval();
} else {
this._eval = return_this;
value = fixed._eval(compressor, depth);
delete this._eval; delete this._eval;
return this; if (value === fixed) return this;
fixed._eval = function() {
return value;
};
} }
if (!HOP(fixed, "_eval")) fixed._eval = function() { if (value && typeof value == "object") {
return value; var escaped = this.definition().escaped;
}; if (escaped && depth > escaped) return this;
if (value && typeof value == "object" && this.definition().escaped) {
delete this._eval;
return this;
} }
this._eval = fixed._eval;
return value; return value;
}); });
var global_objs = { var global_objs = {
@@ -2095,11 +2090,11 @@ merge(Compressor.prototype, {
], ],
}; };
convert_to_predicate(static_values); convert_to_predicate(static_values);
def(AST_PropAccess, function(compressor){ def(AST_PropAccess, function(compressor, depth) {
if (compressor.option("unsafe")) { if (compressor.option("unsafe")) {
var key = this.property; var key = this.property;
if (key instanceof AST_Node) { if (key instanceof AST_Node) {
key = ev(key, compressor); key = key._eval(compressor, depth);
if (key === this.property) return this; if (key === this.property) return this;
} }
var exp = this.expression; var exp = this.expression;
@@ -2108,7 +2103,7 @@ merge(Compressor.prototype, {
if (!(static_values[exp.name] || return_false)(key)) return this; if (!(static_values[exp.name] || return_false)(key)) return this;
val = global_objs[exp.name]; val = global_objs[exp.name];
} else { } else {
val = ev(exp, compressor); val = exp._eval(compressor, depth + 1);
if (!val || val === exp || !HOP(val, key)) return this; if (!val || val === exp || !HOP(val, key)) return this;
} }
return val[key]; return val[key];
@@ -2186,12 +2181,12 @@ merge(Compressor.prototype, {
], ],
}; };
convert_to_predicate(static_fns); convert_to_predicate(static_fns);
def(AST_Call, function(compressor){ def(AST_Call, function(compressor, depth) {
var exp = this.expression; var exp = this.expression;
if (compressor.option("unsafe") && exp instanceof AST_PropAccess) { if (compressor.option("unsafe") && exp instanceof AST_PropAccess) {
var key = exp.property; var key = exp.property;
if (key instanceof AST_Node) { if (key instanceof AST_Node) {
key = ev(key, compressor); key = key._eval(compressor, depth);
if (key === exp.property) return this; if (key === exp.property) return this;
} }
var val; var val;
@@ -2200,13 +2195,13 @@ merge(Compressor.prototype, {
if (!(static_fns[e.name] || return_false)(key)) return this; if (!(static_fns[e.name] || return_false)(key)) return this;
val = global_objs[e.name]; val = global_objs[e.name];
} else { } else {
val = ev(e, compressor); val = e._eval(compressor, depth + 1);
if (val === e || !(val && native_fns[val.constructor.name] || return_false)(key)) return this; if (val === e || !(val && native_fns[val.constructor.name] || return_false)(key)) return this;
} }
var args = []; var args = [];
for (var i = 0, len = this.args.length; i < len; i++) { for (var i = 0, len = this.args.length; i < len; i++) {
var arg = this.args[i]; var arg = this.args[i];
var value = ev(arg, compressor); var value = arg._eval(compressor, depth);
if (arg === value) return this; if (arg === value) return this;
args.push(value); args.push(value);
} }
@@ -3083,7 +3078,7 @@ merge(Compressor.prototype, {
if (node instanceof AST_VarDef) { if (node instanceof AST_VarDef) {
var sym = node.name, def, value; var sym = node.name, def, value;
if (sym.scope === self if (sym.scope === self
&& !(def = sym.definition()).escaped && (def = sym.definition()).escaped != 1
&& !def.single_use && !def.single_use
&& !def.direct_access && !def.direct_access
&& !top_retain(def) && !top_retain(def)
@@ -4698,7 +4693,7 @@ merge(Compressor.prototype, {
if (d.single_use && fixed instanceof AST_Function) { if (d.single_use && fixed instanceof AST_Function) {
if (d.scope !== self.scope if (d.scope !== self.scope
&& (!compressor.option("reduce_funcs") && (!compressor.option("reduce_funcs")
|| d.escaped || d.escaped == 1
|| fixed.inlined)) { || fixed.inlined)) {
d.single_use = false; d.single_use = false;
} else if (recursive_ref(compressor, d)) { } else if (recursive_ref(compressor, d)) {

31
test/compress/reduce_vars.js
View File

@@ -3422,6 +3422,37 @@ escaped_prop_1: {
} }
escaped_prop_2: { escaped_prop_2: {
options = {
collapse_vars: true,
evaluate: true,
inline: true,
passes: 2,
pure_getters: "strict",
reduce_funcs: true,
reduce_vars: true,
side_effects: true,
toplevel: true,
unsafe: true,
unused: true,
}
input: {
var obj = { o: { a: 1 } };
(function(o) {
o.a++;
})(obj.o);
(function(o) {
console.log(o.a);
})(obj.o);
}
expect: {
var obj = { o: { a: 1 } };
obj.o.a++;
console.log(obj.o.a);
}
expect_stdout: "2"
}
escaped_prop_3: {
options = { options = {
reduce_funcs: true, reduce_funcs: true,
reduce_vars: true, reduce_vars: true,