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

fix merge

Browse Source
This commit is contained in:
pborunda 2017-03-16 11:28:32 -07:00
parent af167f0ede
commit 352bdaecb6
1 changed files with 224 additions and 195 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

419
lib/compress.js
View File

@ -99,10 +99,10 @@ function Compressor(options, false_by_default) {
this.top_retain = function(def) { this.top_retain = function(def) {
return top_retain.test(def.name); return top_retain.test(def.name);
}; };
} else if (typeof top_retain === "function") { } else if (typeof top_retain == "function") {
this.top_retain = top_retain; this.top_retain = top_retain;
} else if (top_retain) { } else if (top_retain) {
if (typeof top_retain === "string") { if (typeof top_retain == "string") {
top_retain = top_retain.split(/,/); top_retain = top_retain.split(/,/);
} }
this.top_retain = function(def) { this.top_retain = function(def) {
@ -152,14 +152,25 @@ merge(Compressor.prototype, {
node = node.hoist_declarations(this); node = node.hoist_declarations(this);
was_scope = true; was_scope = true;
} }
// Before https://github.com/mishoo/UglifyJS2/pull/1602 AST_Node.optimize()
// would call AST_Node.transform() if a different instance of AST_Node is
// produced after OPT().
// This corrupts TreeWalker.stack, which cause AST look-ups to malfunction.
// Migrate and defer all children's AST_Node.transform() to below, which
// will now happen after this parent AST_Node has been properly substituted
// thus gives a consistent AST snapshot.
descend(node, this); descend(node, this);
node = node.optimize(this); // Existing code relies on how AST_Node.optimize() worked, and omitting the
if (was_scope && node instanceof AST_Scope) { // following replacement call would result in degraded efficiency of both
node.drop_unused(this); // output and performance.
descend(node, this); descend(node, this);
var opt = node.optimize(this);
if (was_scope && opt instanceof AST_Scope) {
opt.drop_unused(this);
descend(opt, this);
} }
node._squeezed = true; if (opt === node) opt._squeezed = true;
return node; return opt;
} }
}); });
@ -172,8 +183,7 @@ merge(Compressor.prototype, {
if (compressor.has_directive("use asm")) return self; if (compressor.has_directive("use asm")) return self;
var opt = optimizer(self, compressor); var opt = optimizer(self, compressor);
opt._optimized = true; opt._optimized = true;
if (opt === self) return opt; return opt;
return opt.transform(compressor);
}); });
}; };
@ -280,8 +290,12 @@ merge(Compressor.prototype, {
} }
var iife; var iife;
if (node instanceof AST_Function if (node instanceof AST_Function
&& !node.name
&& (iife = tw.parent()) instanceof AST_Call && (iife = tw.parent()) instanceof AST_Call
&& iife.expression === node) { && iife.expression === node) {
// Virtually turn IIFE parameters into variable definitions:
// (function(a,b) {...})(c,d) => (function() {var a=c,b=d; ...})()
// So existing transformation rules can work on them.
node.argnames.forEach(function(arg, i) { node.argnames.forEach(function(arg, i) {
var d = arg.definition(); var d = arg.definition();
d.fixed = iife.args[i] || make_node(AST_Undefined, iife); d.fixed = iife.args[i] || make_node(AST_Undefined, iife);
@ -381,7 +395,7 @@ merge(Compressor.prototype, {
return new ctor(props); return new ctor(props);
}; };
function make_node_from_constant(compressor, val, orig) { function make_node_from_constant(val, orig) {
switch (typeof val) { switch (typeof val) {
case "string": case "string":
return make_node(AST_String, orig, { return make_node(AST_String, orig, {
@ -401,9 +415,9 @@ merge(Compressor.prototype, {
return make_node(AST_Number, orig, { value: val }); return make_node(AST_Number, orig, { value: val });
case "boolean": case "boolean":
return make_node(val ? AST_True : AST_False, orig).transform(compressor); return make_node(val ? AST_True : AST_False, orig);
case "undefined": case "undefined":
return make_node(AST_Undefined, orig).transform(compressor); return make_node(AST_Undefined, orig);
default: default:
if (val === null) { if (val === null) {
return make_node(AST_Null, orig, { value: null }); return make_node(AST_Null, orig, { value: null });
@ -508,6 +522,7 @@ merge(Compressor.prototype, {
var self = compressor.self(); var self = compressor.self();
var var_defs_removed = false; var var_defs_removed = false;
var toplevel = compressor.option("toplevel");
for (var stat_index = statements.length; --stat_index >= 0;) { for (var stat_index = statements.length; --stat_index >= 0;) {
var stat = statements[stat_index]; var stat = statements[stat_index];
if (stat instanceof AST_Definitions) continue; if (stat instanceof AST_Definitions) continue;
@ -545,7 +560,8 @@ merge(Compressor.prototype, {
// Only interested in cases with just one reference to the variable. // Only interested in cases with just one reference to the variable.
var def = self.find_variable && self.find_variable(var_name); var def = self.find_variable && self.find_variable(var_name);
if (!def || !def.references || def.references.length !== 1 || var_name == "arguments") { if (!def || !def.references || def.references.length !== 1
|| var_name == "arguments" || (!toplevel && def.global)) {
side_effects_encountered = true; side_effects_encountered = true;
continue; continue;
} }
@ -911,7 +927,7 @@ merge(Compressor.prototype, {
if (stat instanceof AST_LoopControl) { if (stat instanceof AST_LoopControl) {
var lct = compressor.loopcontrol_target(stat.label); var lct = compressor.loopcontrol_target(stat.label);
if ((stat instanceof AST_Break if ((stat instanceof AST_Break
&& lct instanceof AST_BlockStatement && !(lct instanceof AST_IterationStatement)
&& loop_body(lct) === self) || (stat instanceof AST_Continue && loop_body(lct) === self) || (stat instanceof AST_Continue
&& loop_body(lct) === self)) { && loop_body(lct) === self)) {
if (stat.label) { if (stat.label) {
@ -1195,11 +1211,11 @@ merge(Compressor.prototype, {
} }
} }
}); });
function to_node(compressor, value, orig) { function to_node(value, orig) {
if (value instanceof AST_Node) return make_node(value.CTOR, orig, value); if (value instanceof AST_Node) return make_node(value.CTOR, orig, value);
if (Array.isArray(value)) return make_node(AST_Array, orig, { if (Array.isArray(value)) return make_node(AST_Array, orig, {
elements: value.map(function(value) { elements: value.map(function(value) {
return to_node(compressor, value, orig); return to_node(value, orig);
}) })
}); });
if (value && typeof value == "object") { if (value && typeof value == "object") {
@ -1207,14 +1223,14 @@ merge(Compressor.prototype, {
for (var key in value) { for (var key in value) {
props.push(make_node(AST_ObjectKeyVal, orig, { props.push(make_node(AST_ObjectKeyVal, orig, {
key: key, key: key,
value: to_node(compressor, value[key], orig) value: to_node(value[key], orig)
})); }));
} }
return make_node(AST_Object, orig, { return make_node(AST_Object, orig, {
properties: props properties: props
}); });
} }
return make_node_from_constant(compressor, value, orig); return make_node_from_constant(value, orig);
} }
def(AST_Node, noop); def(AST_Node, noop);
def(AST_Dot, function(compressor, suffix){ def(AST_Dot, function(compressor, suffix){
@ -1225,7 +1241,7 @@ merge(Compressor.prototype, {
var name; var name;
var defines = compressor.option("global_defs"); var defines = compressor.option("global_defs");
if (defines && HOP(defines, (name = this.name + suffix))) { if (defines && HOP(defines, (name = this.name + suffix))) {
var node = to_node(compressor, defines[name], this); var node = to_node(defines[name], this);
var top = compressor.find_parent(AST_Toplevel); var top = compressor.find_parent(AST_Toplevel);
node.walk(new TreeWalker(function(node) { node.walk(new TreeWalker(function(node) {
if (node instanceof AST_SymbolRef) { if (node instanceof AST_SymbolRef) {
@ -1240,45 +1256,40 @@ merge(Compressor.prototype, {
node.DEFMETHOD("_find_defs", func); node.DEFMETHOD("_find_defs", func);
}); });
function best_of(ast1, ast2) { function best_of_expression(ast1, ast2) {
return ast1.print_to_string().length > return ast1.print_to_string().length >
ast2.print_to_string().length ast2.print_to_string().length
? ast2 : ast1; ? ast2 : ast1;
} }
function best_of_statement(ast1, ast2) { function best_of_statement(ast1, ast2) {
return best_of(make_node(AST_SimpleStatement, ast1, { return best_of_expression(make_node(AST_SimpleStatement, ast1, {
body: ast1 body: ast1
}), make_node(AST_SimpleStatement, ast2, { }), make_node(AST_SimpleStatement, ast2, {
body: ast2 body: ast2
})).body; })).body;
} }
function best_of(compressor, ast1, ast2) {
return (first_in_statement(compressor) ? best_of_statement : best_of_expression)(ast1, ast2);
}
// methods to evaluate a constant expression // methods to evaluate a constant expression
(function (def){ (function (def){
// The evaluate method returns an array with one or two // If the node has been successfully reduced to a constant,
// elements. If the node has been successfully reduced to a // then its value is returned; otherwise the element itself
// constant, then the second element tells us the value; // is returned.
// otherwise the second element is missing. The first element // They can be distinguished as constant value is never a
// of the array is always an AST_Node descendant; if // descendant of AST_Node.
// evaluation was successful it's a node that represents the
// constant; otherwise it's the original or a replacement 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;
try { try {
val = this._eval(compressor); var val = this._eval(compressor);
return !val || val instanceof RegExp || typeof val != "object" ? val : this;
} catch(ex) { } catch(ex) {
if (ex !== def) throw ex; if (ex !== def) throw ex;
return [ this ]; return this;
} }
var node;
try {
node = make_node_from_constant(compressor, val, this);
} catch(ex) {
return [ this ];
}
return [ best_of(node, this), val ];
}); });
var unaryPrefix = makePredicate("! ~ - +"); var unaryPrefix = makePredicate("! ~ - +");
AST_Node.DEFMETHOD("is_constant", function(){ AST_Node.DEFMETHOD("is_constant", function(){
@ -1316,8 +1327,8 @@ merge(Compressor.prototype, {
})); }));
} }
var result = this.evaluate(compressor); var result = this.evaluate(compressor);
if (result.length > 1) { if (result !== this) {
return result[1]; return result;
} }
throw new Error(string_template("Cannot evaluate constant [{file}:{line},{col}]", this.start)); throw new Error(string_template("Cannot evaluate constant [{file}:{line},{col}]", this.start));
}); });
@ -1477,9 +1488,9 @@ merge(Compressor.prototype, {
var stat = make_node(AST_SimpleStatement, alt, { var stat = make_node(AST_SimpleStatement, alt, {
body: alt body: alt
}); });
return best_of(negated, stat) === stat ? alt : negated; return best_of_expression(negated, stat) === stat ? alt : negated;
} }
return best_of(negated, alt); return best_of_expression(negated, alt);
} }
def(AST_Node, function(){ def(AST_Node, function(){
return basic_negation(this); return basic_negation(this);
@ -1643,8 +1654,8 @@ merge(Compressor.prototype, {
return thing && thing.aborts(); return thing && thing.aborts();
}; };
(function(def){ (function(def){
def(AST_Statement, function(){ return null }); def(AST_Statement, return_null);
def(AST_Jump, function(){ return this }); def(AST_Jump, return_this);
function block_aborts(){ function block_aborts(){
var n = this.body.length; var n = this.body.length;
return n > 0 && aborts(this.body[n - 1]); return n > 0 && aborts(this.body[n - 1]);
@ -1661,7 +1672,7 @@ merge(Compressor.prototype, {
/* -----[ optimizers ]----- */ /* -----[ optimizers ]----- */
OPT(AST_Directive, function(self, compressor){ OPT(AST_Directive, function(self, compressor){
if (compressor.has_directive(self.value) === "up") { if (compressor.has_directive(self.value) !== self) {
return make_node(AST_EmptyStatement, self); return make_node(AST_EmptyStatement, self);
} }
return self; return self;
@ -1811,10 +1822,12 @@ merge(Compressor.prototype, {
node.name = null; node.name = null;
} }
if (node instanceof AST_Lambda && !(node instanceof AST_Accessor)) { if (node instanceof AST_Lambda && !(node instanceof AST_Accessor)) {
if (!compressor.option("keep_fargs")) { var trim = !compressor.option("keep_fargs");
for (var a = node.argnames, i = a.length; --i >= 0;) { for (var a = node.argnames, i = a.length; --i >= 0;) {
var sym = a[i]; var sym = a[i];
if (!(sym.definition().id in in_use_ids)) { if (!(sym.definition().id in in_use_ids)) {
sym.__unused = true;
if (trim) {
a.pop(); a.pop();
compressor.warn("Dropping unused function argument {name} [{file}:{line},{col}]", { compressor.warn("Dropping unused function argument {name} [{file}:{line},{col}]", {
name : sym.name, name : sym.name,
@ -1823,7 +1836,9 @@ merge(Compressor.prototype, {
col : sym.start.col col : sym.start.col
}); });
} }
else break; }
else {
trim = false;
} }
} }
} }
@ -1902,17 +1917,15 @@ merge(Compressor.prototype, {
} }
return node; return node;
} }
if (drop_vars && assign_as_unused) { if (drop_vars && assign_as_unused
var n = node; && node instanceof AST_Assign
while (n instanceof AST_Assign && node.operator == "="
&& n.operator == "=" && node.left instanceof AST_SymbolRef) {
&& n.left instanceof AST_SymbolRef) { var def = node.left.definition();
var def = n.left.definition(); if (!(def.id in in_use_ids)
if (def.id in in_use_ids && self.variables.get(def.name) === def) {
|| self.variables.get(def.name) !== def) break; return maintain_this_binding(tt.parent(), node, node.right.transform(tt));
n = n.right;
} }
if (n !== node) return n;
} }
if (node instanceof AST_For) { if (node instanceof AST_For) {
descend(node, this); descend(node, this);
@ -1976,7 +1989,7 @@ merge(Compressor.prototype, {
vars.set(def.name.name, def); vars.set(def.name.name, def);
++vars_found; ++vars_found;
}); });
var seq = node.to_assignments(); var seq = node.to_assignments(compressor);
var p = tt.parent(); var p = tt.parent();
if (p instanceof AST_ForIn && p.init === node) { if (p instanceof AST_ForIn && p.init === node) {
if (seq == null) { if (seq == null) {
@ -2072,14 +2085,6 @@ merge(Compressor.prototype, {
// drop_side_effect_free() // drop_side_effect_free()
// remove side-effect-free parts which only affects return value // remove side-effect-free parts which only affects return value
(function(def){ (function(def){
function return_this() {
return this;
}
function return_null() {
return null;
}
// Drop side-effect-free elements from an array of expressions. // Drop side-effect-free elements from an array of expressions.
// Returns an array of expressions with side-effects or null // Returns an array of expressions with side-effects or null
// if all elements were dropped. Note: original array may be // if all elements were dropped. Note: original array may be
@ -2236,27 +2241,24 @@ merge(Compressor.prototype, {
}); });
OPT(AST_DWLoop, function(self, compressor){ OPT(AST_DWLoop, function(self, compressor){
var cond = self.condition.evaluate(compressor);
self.condition = cond[0];
if (!compressor.option("loops")) return self; if (!compressor.option("loops")) return self;
if (cond.length > 1) { var cond = self.condition.evaluate(compressor);
if (cond[1]) { if (cond !== self.condition) {
if (cond) {
return make_node(AST_For, self, { return make_node(AST_For, self, {
body: self.body body: self.body
}); });
} else if (self instanceof AST_While) { } else if (compressor.option("dead_code") && self instanceof AST_While) {
if (compressor.option("dead_code")) { var a = [];
var a = []; extract_declarations_from_unreachable_code(compressor, self.body, a);
extract_declarations_from_unreachable_code(compressor, self.body, a); return make_node(AST_BlockStatement, self, { body: a });
return make_node(AST_BlockStatement, self, { body: a });
}
} else { } else {
// self instanceof AST_Do cond = make_node_from_constant(cond, self.condition).transform(compressor);
return self; self.condition = best_of_expression(cond, self.condition);
} }
} }
if (self instanceof AST_While) { if (self instanceof AST_While) {
return make_node(AST_For, self, self).transform(compressor); return make_node(AST_For, self, self).optimize(compressor);
} }
return self; return self;
}); });
@ -2278,7 +2280,7 @@ merge(Compressor.prototype, {
var first = self.body instanceof AST_BlockStatement ? self.body.body[0] : self.body; var first = self.body instanceof AST_BlockStatement ? self.body.body[0] : self.body;
if (first instanceof AST_If) { if (first instanceof AST_If) {
if (first.body instanceof AST_Break if (first.body instanceof AST_Break
&& compressor.loopcontrol_target(first.body.label) === self) { && compressor.loopcontrol_target(first.body.label) === compressor.self()) {
if (self.condition) { if (self.condition) {
self.condition = make_node(AST_Binary, self.condition, { self.condition = make_node(AST_Binary, self.condition, {
left: self.condition, left: self.condition,
@ -2291,7 +2293,7 @@ merge(Compressor.prototype, {
drop_it(first.alternative); drop_it(first.alternative);
} }
else if (first.alternative instanceof AST_Break else if (first.alternative instanceof AST_Break
&& compressor.loopcontrol_target(first.alternative.label) === self) { && compressor.loopcontrol_target(first.alternative.label) === compressor.self()) {
if (self.condition) { if (self.condition) {
self.condition = make_node(AST_Binary, self.condition, { self.condition = make_node(AST_Binary, self.condition, {
left: self.condition, left: self.condition,
@ -2307,27 +2309,25 @@ merge(Compressor.prototype, {
}; };
OPT(AST_For, function(self, compressor){ OPT(AST_For, function(self, compressor){
var cond = self.condition;
if (cond) {
cond = cond.evaluate(compressor);
self.condition = cond[0];
}
if (!compressor.option("loops")) return self; if (!compressor.option("loops")) return self;
if (cond) { if (self.condition) {
if (cond.length > 1 && !cond[1]) { var cond = self.condition.evaluate(compressor);
if (compressor.option("dead_code")) { if (compressor.option("dead_code") && !cond) {
var a = []; var a = [];
if (self.init instanceof AST_Statement) { if (self.init instanceof AST_Statement) {
a.push(self.init); a.push(self.init);
}
else if (self.init) {
a.push(make_node(AST_SimpleStatement, self.init, {
body: self.init
}));
}
extract_declarations_from_unreachable_code(compressor, self.body, a);
return make_node(AST_BlockStatement, self, { body: a });
} }
else if (self.init) {
a.push(make_node(AST_SimpleStatement, self.init, {
body: self.init
}));
}
extract_declarations_from_unreachable_code(compressor, self.body, a);
return make_node(AST_BlockStatement, self, { body: a });
}
if (cond !== self.condition) {
cond = make_node_from_constant(cond, self.condition).transform(compressor);
self.condition = best_of_expression(cond, self.condition);
} }
} }
if_break_in_loop(self, compressor); if_break_in_loop(self, compressor);
@ -2343,9 +2343,8 @@ merge(Compressor.prototype, {
// “has no side effects”; also it doesn't work for cases like // “has no side effects”; also it doesn't work for cases like
// `x && true`, though it probably should. // `x && true`, though it probably should.
var cond = self.condition.evaluate(compressor); var cond = self.condition.evaluate(compressor);
self.condition = cond[0]; if (cond !== self.condition) {
if (cond.length > 1) { if (cond) {
if (cond[1]) {
compressor.warn("Condition always true [{file}:{line},{col}]", self.condition.start); compressor.warn("Condition always true [{file}:{line},{col}]", self.condition.start);
if (compressor.option("dead_code")) { if (compressor.option("dead_code")) {
var a = []; var a = [];
@ -2353,7 +2352,7 @@ merge(Compressor.prototype, {
extract_declarations_from_unreachable_code(compressor, self.alternative, a); extract_declarations_from_unreachable_code(compressor, self.alternative, a);
} }
a.push(self.body); a.push(self.body);
return make_node(AST_BlockStatement, self, { body: a }).transform(compressor); return make_node(AST_BlockStatement, self, { body: a }).optimize(compressor);
} }
} else { } else {
compressor.warn("Condition always false [{file}:{line},{col}]", self.condition.start); compressor.warn("Condition always false [{file}:{line},{col}]", self.condition.start);
@ -2361,9 +2360,11 @@ merge(Compressor.prototype, {
var a = []; var a = [];
extract_declarations_from_unreachable_code(compressor, self.body, a); extract_declarations_from_unreachable_code(compressor, self.body, a);
if (self.alternative) a.push(self.alternative); if (self.alternative) a.push(self.alternative);
return make_node(AST_BlockStatement, self, { body: a }).transform(compressor); return make_node(AST_BlockStatement, self, { body: a }).optimize(compressor);
} }
} }
cond = make_node_from_constant(cond, self.condition).transform(compressor);
self.condition = best_of_expression(cond, self.condition);
} }
var negated = self.condition.negate(compressor); var negated = self.condition.negate(compressor);
var self_condition_length = self.condition.print_to_string().length; var self_condition_length = self.condition.print_to_string().length;
@ -2380,8 +2381,8 @@ merge(Compressor.prototype, {
} }
if (is_empty(self.body) && is_empty(self.alternative)) { if (is_empty(self.body) && is_empty(self.alternative)) {
return make_node(AST_SimpleStatement, self.condition, { return make_node(AST_SimpleStatement, self.condition, {
body: self.condition body: self.condition.clone()
}).transform(compressor); }).optimize(compressor);
} }
if (self.body instanceof AST_SimpleStatement if (self.body instanceof AST_SimpleStatement
&& self.alternative instanceof AST_SimpleStatement) { && self.alternative instanceof AST_SimpleStatement) {
@ -2391,7 +2392,7 @@ merge(Compressor.prototype, {
consequent : statement_to_expression(self.body), consequent : statement_to_expression(self.body),
alternative : statement_to_expression(self.alternative) alternative : statement_to_expression(self.alternative)
}) })
}).transform(compressor); }).optimize(compressor);
} }
if (is_empty(self.alternative) && self.body instanceof AST_SimpleStatement) { if (is_empty(self.alternative) && self.body instanceof AST_SimpleStatement) {
if (self_condition_length === negated_length && !negated_is_best if (self_condition_length === negated_length && !negated_is_best
@ -2407,14 +2408,14 @@ merge(Compressor.prototype, {
left : negated, left : negated,
right : statement_to_expression(self.body) right : statement_to_expression(self.body)
}) })
}).transform(compressor); }).optimize(compressor);
return make_node(AST_SimpleStatement, self, { return make_node(AST_SimpleStatement, self, {
body: make_node(AST_Binary, self, { body: make_node(AST_Binary, self, {
operator : "&&", operator : "&&",
left : self.condition, left : self.condition,
right : statement_to_expression(self.body) right : statement_to_expression(self.body)
}) })
}).transform(compressor); }).optimize(compressor);
} }
if (self.body instanceof AST_EmptyStatement if (self.body instanceof AST_EmptyStatement
&& self.alternative && self.alternative
@ -2425,7 +2426,7 @@ merge(Compressor.prototype, {
left : self.condition, left : self.condition,
right : statement_to_expression(self.alternative) right : statement_to_expression(self.alternative)
}) })
}).transform(compressor); }).optimize(compressor);
} }
if (self.body instanceof AST_Exit if (self.body instanceof AST_Exit
&& self.alternative instanceof AST_Exit && self.alternative instanceof AST_Exit
@ -2435,18 +2436,21 @@ merge(Compressor.prototype, {
condition : self.condition, condition : self.condition,
consequent : self.body.value || make_node(AST_Undefined, self.body), consequent : self.body.value || make_node(AST_Undefined, self.body),
alternative : self.alternative.value || make_node(AST_Undefined, self.alternative) alternative : self.alternative.value || make_node(AST_Undefined, self.alternative)
}) }).transform(compressor)
}).transform(compressor); }).optimize(compressor);
} }
if (self.body instanceof AST_If if (self.body instanceof AST_If
&& !self.body.alternative && !self.body.alternative
&& !self.alternative) { && !self.alternative) {
self.condition = make_node(AST_Binary, self.condition, { self = make_node(AST_If, self, {
operator: "&&", condition: make_node(AST_Binary, self.condition, {
left: self.condition, operator: "&&",
right: self.body.condition left: self.condition,
}).transform(compressor); right: self.body.condition
self.body = self.body.body; }),
body: self.body.body,
alternative: null
});
} }
if (aborts(self.body)) { if (aborts(self.body)) {
if (self.alternative) { if (self.alternative) {
@ -2454,7 +2458,7 @@ merge(Compressor.prototype, {
self.alternative = null; self.alternative = null;
return make_node(AST_BlockStatement, self, { return make_node(AST_BlockStatement, self, {
body: [ self, alt ] body: [ self, alt ]
}).transform(compressor); }).optimize(compressor);
} }
} }
if (aborts(self.alternative)) { if (aborts(self.alternative)) {
@ -2464,7 +2468,7 @@ merge(Compressor.prototype, {
self.alternative = null; self.alternative = null;
return make_node(AST_BlockStatement, self, { return make_node(AST_BlockStatement, self, {
body: [ self, body ] body: [ self, body ]
}).transform(compressor); }).optimize(compressor);
} }
return self; return self;
}); });
@ -2488,12 +2492,12 @@ merge(Compressor.prototype, {
} }
break; break;
} }
var exp = self.expression.evaluate(compressor); var value = self.expression.evaluate(compressor);
out: if (exp.length == 2) try { out: if (value !== self.expression) try {
// constant expression // constant expression
self.expression = exp[0]; var expression = make_node_from_constant(value, self.expression);
self.expression = best_of_expression(expression, self.expression);
if (!compressor.option("dead_code")) break out; if (!compressor.option("dead_code")) break out;
var value = exp[1];
var in_if = false; var in_if = false;
var in_block = false; var in_block = false;
var started = false; var started = false;
@ -2540,11 +2544,11 @@ merge(Compressor.prototype, {
if (stopped) return MAP.skip; if (stopped) return MAP.skip;
if (node instanceof AST_Case) { if (node instanceof AST_Case) {
var exp = node.expression.evaluate(compressor); var exp = node.expression.evaluate(compressor);
if (exp.length < 2) { if (exp === node.expression) {
// got a case with non-constant expression, baling out // got a case with non-constant expression, baling out
throw self; throw self;
} }
if (exp[1] === value || started) { if (exp === value || started) {
started = true; started = true;
if (aborts(node)) stopped = true; if (aborts(node)) stopped = true;
descend(node, this); descend(node, this);
@ -2578,7 +2582,8 @@ merge(Compressor.prototype, {
this.definitions.forEach(function(def){ def.value = null }); this.definitions.forEach(function(def){ def.value = null });
}); });
AST_Definitions.DEFMETHOD("to_assignments", function(){ AST_Definitions.DEFMETHOD("to_assignments", function(compressor){
var reduce_vars = compressor.option("reduce_vars");
var assignments = this.definitions.reduce(function(a, def){ var assignments = this.definitions.reduce(function(a, def){
if (def.value) { if (def.value) {
var name = make_node(AST_SymbolRef, def.name, def.name); var name = make_node(AST_SymbolRef, def.name, def.name);
@ -2587,6 +2592,7 @@ merge(Compressor.prototype, {
left : name, left : name,
right : def.value right : def.value
})); }));
if (reduce_vars) name.definition().fixed = false;
} }
return a; return a;
}, []); }, []);
@ -2612,6 +2618,9 @@ merge(Compressor.prototype, {
exp = def.fixed; exp = def.fixed;
if (compressor.option("unused") if (compressor.option("unused")
&& def.references.length == 1 && def.references.length == 1
&& !(def.scope.uses_arguments
&& def.orig[0] instanceof AST_SymbolFunarg)
&& !def.scope.uses_eval
&& compressor.find_parent(AST_Scope) === def.scope) { && compressor.find_parent(AST_Scope) === def.scope) {
self.expression = exp; self.expression = exp;
} }
@ -2620,16 +2629,26 @@ merge(Compressor.prototype, {
if (compressor.option("unused") if (compressor.option("unused")
&& exp instanceof AST_Function && exp instanceof AST_Function
&& !exp.uses_arguments && !exp.uses_arguments
&& !exp.uses_eval && !exp.uses_eval) {
&& self.args.length > exp.argnames.length) { var pos = 0, last = 0;
var end = exp.argnames.length; for (var i = 0, len = self.args.length; i < len; i++) {
for (var i = end, len = self.args.length; i < len; i++) { var trim = i >= exp.argnames.length;
var node = self.args[i].drop_side_effect_free(compressor); if (trim || exp.argnames[i].__unused) {
if (node) { var node = self.args[i].drop_side_effect_free(compressor);
self.args[end++] = node; if (node) {
self.args[pos++] = node;
} else if (!trim) {
self.args[pos++] = make_node(AST_Number, self.args[i], {
value: 0
});
continue;
}
} else {
self.args[pos++] = self.args[i];
} }
last = pos;
} }
self.args.length = end; self.args.length = last;
} }
if (compressor.option("unsafe")) { if (compressor.option("unsafe")) {
if (exp instanceof AST_SymbolRef && exp.undeclared()) { if (exp instanceof AST_SymbolRef && exp.undeclared()) {
@ -2745,15 +2764,14 @@ merge(Compressor.prototype, {
var separator; var separator;
if (self.args.length > 0) { if (self.args.length > 0) {
separator = self.args[0].evaluate(compressor); separator = self.args[0].evaluate(compressor);
if (separator.length < 2) break EXIT; // not a constant if (separator === self.args[0]) break EXIT; // not a constant
separator = separator[1];
} }
var elements = []; var elements = [];
var consts = []; var consts = [];
exp.expression.elements.forEach(function(el) { exp.expression.elements.forEach(function(el) {
el = el.evaluate(compressor); var value = el.evaluate(compressor);
if (el.length > 1) { if (value !== el) {
consts.push(el[1]); consts.push(value);
} else { } else {
if (consts.length > 0) { if (consts.length > 0) {
elements.push(make_node(AST_String, self, { elements.push(make_node(AST_String, self, {
@ -2761,7 +2779,7 @@ merge(Compressor.prototype, {
})); }));
consts.length = 0; consts.length = 0;
} }
elements.push(el[0]); elements.push(el);
} }
}); });
if (consts.length > 0) { if (consts.length > 0) {
@ -2802,7 +2820,7 @@ merge(Compressor.prototype, {
node.expression = node.expression.clone(); node.expression = node.expression.clone();
node.expression.expression = node.expression.expression.clone(); node.expression.expression = node.expression.expression.clone();
node.expression.expression.elements = elements; node.expression.expression.elements = elements;
return best_of(self, node); return best_of(compressor, self, node);
} }
} }
if (compressor.option("drop_error")) { if (compressor.option("drop_error")) {
@ -2987,8 +3005,7 @@ merge(Compressor.prototype, {
return e.expression; return e.expression;
} }
if (e instanceof AST_Binary) { if (e instanceof AST_Binary) {
var statement = first_in_statement(compressor); self = best_of(compressor, self, e.negate(compressor, first_in_statement(compressor)));
self = (statement ? best_of_statement : best_of)(self, e.negate(compressor, statement));
} }
break; break;
case "typeof": case "typeof":
@ -3001,7 +3018,15 @@ merge(Compressor.prototype, {
}).optimize(compressor); }).optimize(compressor);
} }
} }
return self.evaluate(compressor)[0]; // avoids infinite recursion of numerals
if (self.operator != "-" || !(self.expression instanceof AST_Number)) {
var ev = self.evaluate(compressor);
if (ev !== self) {
ev = make_node_from_constant(ev, self).optimize(compressor);
return best_of(compressor, ev, self);
}
}
return self;
}); });
function has_side_effects_or_prop_access(node, compressor) { function has_side_effects_or_prop_access(node, compressor) {
@ -3039,16 +3064,6 @@ merge(Compressor.prototype, {
var commutativeOperators = makePredicate("== === != !== * & | ^"); var commutativeOperators = makePredicate("== === != !== * & | ^");
OPT(AST_Binary, function(self, compressor){ OPT(AST_Binary, function(self, compressor){
var lhs = self.left.evaluate(compressor);
var rhs = self.right.evaluate(compressor);
if (lhs.length > 1 && lhs[0].is_constant() !== self.left.is_constant()
|| rhs.length > 1 && rhs[0].is_constant() !== self.right.is_constant()) {
return make_node(AST_Binary, self, {
operator: self.operator,
left: lhs[0],
right: rhs[0]
}).optimize(compressor);
}
function reversible() { function reversible() {
return self.left instanceof AST_Constant return self.left instanceof AST_Constant
|| self.right instanceof AST_Constant || self.right instanceof AST_Constant
@ -3133,48 +3148,48 @@ merge(Compressor.prototype, {
case "&&": case "&&":
var ll = self.left.evaluate(compressor); var ll = self.left.evaluate(compressor);
var rr = self.right.evaluate(compressor); var rr = self.right.evaluate(compressor);
if ((ll.length > 1 && !ll[1]) || (rr.length > 1 && !rr[1])) { if (!ll || !rr) {
compressor.warn("Boolean && always false [{file}:{line},{col}]", self.start); compressor.warn("Boolean && always false [{file}:{line},{col}]", self.start);
return make_node(AST_Seq, self, { return make_node(AST_Seq, self, {
car: self.left, car: self.left,
cdr: make_node(AST_False, self) cdr: make_node(AST_False, self)
}).optimize(compressor); }).optimize(compressor);
} }
if (ll.length > 1 && ll[1]) { if (ll !== self.left && ll) {
return rr[0]; return self.right.optimize(compressor);
} }
if (rr.length > 1 && rr[1]) { if (rr !== self.right && rr) {
return ll[0]; return self.left.optimize(compressor);
} }
break; break;
case "||": case "||":
var ll = self.left.evaluate(compressor); var ll = self.left.evaluate(compressor);
var rr = self.right.evaluate(compressor); var rr = self.right.evaluate(compressor);
if ((ll.length > 1 && ll[1]) || (rr.length > 1 && rr[1])) { if (ll !== self.left && ll || rr !== self.right && rr) {
compressor.warn("Boolean || always true [{file}:{line},{col}]", self.start); compressor.warn("Boolean || always true [{file}:{line},{col}]", self.start);
return make_node(AST_Seq, self, { return make_node(AST_Seq, self, {
car: self.left, car: self.left,
cdr: make_node(AST_True, self) cdr: make_node(AST_True, self)
}).optimize(compressor); }).optimize(compressor);
} }
if (ll.length > 1 && !ll[1]) { if (!ll) {
return rr[0]; return self.right.optimize(compressor);
} }
if (rr.length > 1 && !rr[1]) { if (!rr) {
return ll[0]; return self.left.optimize(compressor);
} }
break; break;
case "+": case "+":
var ll = self.left.evaluate(compressor); var ll = self.left.evaluate(compressor);
var rr = self.right.evaluate(compressor); var rr = self.right.evaluate(compressor);
if (ll.length > 1 && ll[0] instanceof AST_String && ll[1]) { if (ll && typeof ll == "string") {
compressor.warn("+ in boolean context always true [{file}:{line},{col}]", self.start); compressor.warn("+ in boolean context always true [{file}:{line},{col}]", self.start);
return make_node(AST_Seq, self, { return make_node(AST_Seq, self, {
car: self.right, car: self.right,
cdr: make_node(AST_True, self) cdr: make_node(AST_True, self)
}).optimize(compressor); }).optimize(compressor);
} }
if (rr.length > 1 && rr[0] instanceof AST_String && rr[1]) { if (rr && typeof rr == "string") {
compressor.warn("+ in boolean context always true [{file}:{line},{col}]", self.start); compressor.warn("+ in boolean context always true [{file}:{line},{col}]", self.start);
return make_node(AST_Seq, self, { return make_node(AST_Seq, self, {
car: self.left, car: self.left,
@ -3186,12 +3201,11 @@ merge(Compressor.prototype, {
if (compressor.option("comparisons") && self.is_boolean()) { if (compressor.option("comparisons") && self.is_boolean()) {
if (!(compressor.parent() instanceof AST_Binary) if (!(compressor.parent() instanceof AST_Binary)
|| compressor.parent() instanceof AST_Assign) { || compressor.parent() instanceof AST_Assign) {
var statement = first_in_statement(compressor);
var negated = make_node(AST_UnaryPrefix, self, { var negated = make_node(AST_UnaryPrefix, self, {
operator: "!", operator: "!",
expression: self.negate(compressor, statement) expression: self.negate(compressor, first_in_statement(compressor))
}); });
self = (statement ? best_of_statement : best_of)(self, negated); self = best_of(compressor, self, negated);
} }
if (compressor.option("unsafe_comps")) { if (compressor.option("unsafe_comps")) {
switch (self.operator) { switch (self.operator) {
@ -3343,9 +3357,9 @@ merge(Compressor.prototype, {
}); });
if (self.right instanceof AST_Constant if (self.right instanceof AST_Constant
&& !(self.left instanceof AST_Constant)) { && !(self.left instanceof AST_Constant)) {
self = best_of(reversed, self); self = best_of(compressor, reversed, self);
} else { } else {
self = best_of(self, reversed); self = best_of(compressor, self, reversed);
} }
} }
if (associative && self.is_number(compressor)) { if (associative && self.is_number(compressor)) {
@ -3442,7 +3456,12 @@ merge(Compressor.prototype, {
self.right = self.right.right; self.right = self.right.right;
return self.transform(compressor); return self.transform(compressor);
} }
return self.evaluate(compressor)[0]; var ev = self.evaluate(compressor);
if (ev !== self) {
ev = make_node_from_constant(ev, self).optimize(compressor);
return best_of(compressor, ev, self);
}
return self;
}); });
OPT(AST_SymbolRef, function(self, compressor){ OPT(AST_SymbolRef, function(self, compressor){
@ -3457,11 +3476,11 @@ merge(Compressor.prototype, {
&& (!self.scope.uses_with || !compressor.find_parent(AST_With))) { && (!self.scope.uses_with || !compressor.find_parent(AST_With))) {
switch (self.name) { switch (self.name) {
case "undefined": case "undefined":
return make_node(AST_Undefined, self).transform(compressor); return make_node(AST_Undefined, self).optimize(compressor);
case "NaN": case "NaN":
return make_node(AST_NaN, self).transform(compressor); return make_node(AST_NaN, self).optimize(compressor);
case "Infinity": case "Infinity":
return make_node(AST_Infinity, self).transform(compressor); return make_node(AST_Infinity, self).optimize(compressor);
} }
} }
if (compressor.option("evaluate") && compressor.option("reduce_vars")) { if (compressor.option("evaluate") && compressor.option("reduce_vars")) {
@ -3469,18 +3488,20 @@ merge(Compressor.prototype, {
if (d.fixed) { if (d.fixed) {
if (d.should_replace === undefined) { if (d.should_replace === undefined) {
var init = d.fixed.evaluate(compressor); var init = d.fixed.evaluate(compressor);
if (init.length > 1) { if (init !== d.fixed) {
var value = init[0].print_to_string().length; init = make_node_from_constant(init, d.fixed).optimize(compressor);
init = best_of_expression(init, d.fixed);
var value = init.print_to_string().length;
var name = d.name.length; var name = d.name.length;
var freq = d.references.length; var freq = d.references.length;
var overhead = d.global || !freq ? 0 : (name + 2 + value) / freq; var overhead = d.global || !freq ? 0 : (name + 2 + value) / freq;
d.should_replace = value <= name + overhead ? init[0] : false; d.should_replace = value <= name + overhead ? init : false;
} else { } else {
d.should_replace = false; d.should_replace = false;
} }
} }
if (d.should_replace) { if (d.should_replace) {
return d.should_replace; return d.should_replace.clone(true);
} }
} }
} }
@ -3545,8 +3566,8 @@ merge(Compressor.prototype, {
return AST_Seq.cons(car, self); return AST_Seq.cons(car, self);
} }
var cond = self.condition.evaluate(compressor); var cond = self.condition.evaluate(compressor);
if (cond.length > 1) { if (cond !== self.condition) {
if (cond[1]) { if (cond) {
compressor.warn("Condition always true [{file}:{line},{col}]", self.start); compressor.warn("Condition always true [{file}:{line},{col}]", self.start);
return maintain_this_binding(compressor.parent(), self, self.consequent); return maintain_this_binding(compressor.parent(), self, self.consequent);
} else { } else {
@ -3554,9 +3575,8 @@ merge(Compressor.prototype, {
return maintain_this_binding(compressor.parent(), self, self.alternative); return maintain_this_binding(compressor.parent(), self, self.alternative);
} }
} }
var statement = first_in_statement(compressor); var negated = cond.negate(compressor, first_in_statement(compressor));
var negated = cond[0].negate(compressor, statement); if (best_of(compressor, cond, negated) === negated) {
if ((statement ? best_of_statement : best_of)(cond[0], negated) === negated) {
self = make_node(AST_Conditional, self, { self = make_node(AST_Conditional, self, {
condition: negated, condition: negated,
consequent: self.alternative, consequent: self.alternative,
@ -3736,7 +3756,12 @@ merge(Compressor.prototype, {
}); });
} }
} }
return self.evaluate(compressor)[0]; var ev = self.evaluate(compressor);
if (ev !== self) {
ev = make_node_from_constant(ev, self).optimize(compressor);
return best_of(compressor, ev, self);
}
return self;
}); });
OPT(AST_Dot, function(self, compressor){ OPT(AST_Dot, function(self, compressor){
@ -3775,13 +3800,17 @@ merge(Compressor.prototype, {
break; break;
} }
} }
return self.evaluate(compressor)[0]; var ev = self.evaluate(compressor);
if (ev !== self) {
ev = make_node_from_constant(ev, self).optimize(compressor);
return best_of(compressor, ev, self);
}
return self;
}); });
function literals_in_boolean_context(self, compressor) { function literals_in_boolean_context(self, compressor) {
if (compressor.option("booleans") && compressor.in_boolean_context()) { if (compressor.option("booleans") && compressor.in_boolean_context()) {
var best = first_in_statement(compressor) ? best_of_statement : best_of; return best_of(compressor, self, make_node(AST_Seq, self, {
return best(self, make_node(AST_Seq, self, {
car: self, car: self,
cdr: make_node(AST_True, self) cdr: make_node(AST_True, self)
}).optimize(compressor)); }).optimize(compressor));