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enhance unsafe evaluate (#3370)
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@alexlamsl
alexlamsl committed Apr 20, 2019
1 parent a438e2f commit 855964a
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Showing 3 changed files with 72 additions and 11 deletions.
54 changes: 45 additions & 9 deletions lib/compress.js
View file
Expand Up @@ -312,8 +312,22 @@ merge(Compressor.prototype, {
return value instanceof AST_SymbolRef && value.fixed_value() || value;
}

function is_read_only_fn(value, name) {
if (value instanceof AST_Boolean) return native_fns.Boolean[name];
if (value instanceof AST_Number) return native_fns.Number[name];
if (value instanceof AST_String) return native_fns.String[name];
if (name == "valueOf") return false;
if (value instanceof AST_Array) return native_fns.Array[name];
if (value instanceof AST_Function) return native_fns.Function[name];
if (value instanceof AST_Object) return native_fns.Object[name];
if (value instanceof AST_RegExp) return native_fns.RegExp[name];
}

function is_modified(compressor, tw, node, value, level, immutable) {
var parent = tw.parent(level);
if (compressor.option("unsafe") && parent instanceof AST_Dot && is_read_only_fn(value, parent.property)) {
return;
}
var lhs = is_lhs(node, parent);
if (lhs) return lhs;
if (!immutable
Expand Down Expand Up @@ -344,7 +358,7 @@ merge(Compressor.prototype, {
def.assignments = 0;
def.chained = false;
def.direct_access = false;
def.escaped = false;
def.escaped = [];
def.fixed = !def.scope.pinned()
&& !compressor.exposed(def)
&& !(def.init instanceof AST_Function && def.init !== def.scope)
Expand Down Expand Up @@ -483,8 +497,9 @@ merge(Compressor.prototype, {
|| parent instanceof AST_Call && (node !== parent.expression || parent instanceof AST_New)
|| parent instanceof AST_Exit && node === parent.value && node.scope !== d.scope
|| parent instanceof AST_VarDef && node === parent.value) {
d.escaped.push(parent);
if (depth > 1 && !(value && value.is_constant_expression(scope))) depth = 1;
if (!d.escaped || d.escaped > depth) d.escaped = depth;
if (!d.escaped.depth || d.escaped.depth > depth) d.escaped.depth = depth;
return;
} else if (parent instanceof AST_Array
|| parent instanceof AST_Binary && lazy_op[parent.operator]
Expand Down Expand Up @@ -742,8 +757,8 @@ merge(Compressor.prototype, {
d.fixed = false;
}
}
mark_escaped(tw, d, this.scope, this, value, 0, 1);
}
mark_escaped(tw, d, this.scope, this, value, 0, 1);
var parent;
if (d.fixed instanceof AST_Defun
&& !((parent = tw.parent()) instanceof AST_Call && parent.expression === this)) {
Expand Down Expand Up @@ -1579,9 +1594,14 @@ merge(Compressor.prototype, {
lvalues[candidate.name.name] = lhs;
}
var tw = new TreeWalker(function(node) {
var sym = root_expr(node);
if (sym instanceof AST_SymbolRef || sym instanceof AST_This) {
lvalues[sym.name] = lvalues[sym.name] || is_modified(compressor, tw, node, node, 0);
var value;
if (node instanceof AST_SymbolRef) {
value = node.fixed_value() || node;
} else if (node instanceof AST_This) {
value = node;
}
if (value && !lvalues[node.name]) {
lvalues[node.name] = is_modified(compressor, tw, node, value, 0);
}
});
expr.walk(tw);
Expand Down Expand Up @@ -2847,9 +2867,25 @@ merge(Compressor.prototype, {
}
if (value && typeof value == "object") {
var escaped = this.definition().escaped;
if (escaped && depth > escaped) return this;
switch (escaped.length) {
case 0:
break;
case 1:
if (contains_ref(escaped[0], this)) break;
default:
if (depth > escaped.depth) return this;
}
}
return value;

function contains_ref(expr, ref) {
var found = false;
expr.walk(new TreeWalker(function(node) {
if (found) return true;
if (node === ref) return found = true;
}));
return found;
}
});
var global_objs = {
Array: Array,
Expand Down Expand Up @@ -3983,7 +4019,7 @@ merge(Compressor.prototype, {
var def = sym.definition();
if (def.assignments != count) return;
if (def.direct_access) return;
if (def.escaped == 1) return;
if (def.escaped.depth == 1) return;
if (def.references.length == count) return;
if (def.single_use) return;
if (top_retain(def)) return;
Expand Down Expand Up @@ -5863,7 +5899,7 @@ merge(Compressor.prototype, {
var single_use = def.single_use && !(parent instanceof AST_Call && parent.is_expr_pure(compressor));
if (single_use && fixed instanceof AST_Lambda) {
if (def.scope !== self.scope
&& (!compressor.option("reduce_funcs") || def.escaped == 1 || fixed.inlined)) {
&& (!compressor.option("reduce_funcs") || def.escaped.depth == 1 || fixed.inlined)) {
single_use = false;
} else if (recursive_ref(compressor, def)) {
single_use = false;
Expand Down
25 changes: 25 additions & 0 deletions test/compress/evaluate.js
View file
Expand Up @@ -1687,3 +1687,28 @@ try_increment: {
}
expect_stdout: "1"
}

unsafe_escaped: {
options = {
evaluate: true,
inline: true,
passes: 3,
reduce_vars: true,
side_effects: true,
unsafe: true,
unused: true,
}
input: {
(function(a) {
console.log(function(index) {
return a[index];
}(function(term) {
return a.indexOf(term);
}("PASS")));
})([ "PASS" ]);
}
expect: {
console.log("PASS");
}
expect_stdout: "PASS"
}
4 changes: 2 additions & 2 deletions test/compress/reduce_vars.js
View file
Expand Up @@ -281,8 +281,8 @@ unsafe_evaluate_escaped: {
console.log(function(){ var o={p:3},a=[o]; console.log(a[0].p++); return o.p; }());
}
expect: {
console.log(function(){ var o={p:1}; console.log(o, o.p); return o.p; }());
console.log(function(){ var o={p:2}; console.log(o.p, o); return o.p; }());
console.log(function(){ var o={p:1}; console.log(o, 1); return o.p; }());
console.log(function(){ var o={p:2}; console.log(2, o); return o.p; }());
console.log(function(){ var o={p:3},a=[o]; console.log(a[0].p++); return o.p; }());
}
expect_stdout: true
Expand Down

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