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Merge branch 'master' into harmony-v3.1.7

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This commit is contained in:
alexlamsl
2017-11-05 15:47:40 +08:00
parent 29bbc41dfe f46281e2b7
commit df9c8dfd72
8 changed files with 535 additions and 85 deletions
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190
lib/compress.js
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@@ -291,7 +291,7 @@ merge(Compressor.prototype, {
self.transform(tt);
});
AST_Node.DEFMETHOD("reset_opt_flags", function(compressor) {
AST_Toplevel.DEFMETHOD("reset_opt_flags", function(compressor) {
var reduce_vars = compressor.option("reduce_vars");
var unused = compressor.option("unused");
// Stack of look-up tables to keep track of whether a `SymbolDef` has been
@@ -322,12 +322,18 @@ merge(Compressor.prototype, {
d.fixed = false;
} else if (d.fixed) {
var value = node.fixed_value();
if (unused && !compressor.exposed(d)) {
d.single_use = value
&& d.references.length == 1
&& loop_ids[d.id] === in_loop
&& d.scope === node.scope
&& value.is_constant_expression();
if (unused && !compressor.exposed(d) && value && d.references.length == 1) {
if (value instanceof AST_Lambda) {
d.single_use = d.scope === node.scope
&& !(d.orig[0] instanceof AST_SymbolFunarg)
|| value.is_constant_expression(node.scope);
} else {
d.single_use = d.scope === node.scope
&& loop_ids[d.id] === in_loop
&& value.is_constant_expression();
}
} else {
d.single_use = false;
}
if (is_modified(node, value, 0, is_immutable(value))) {
if (d.single_use) {
@@ -390,6 +396,10 @@ merge(Compressor.prototype, {
} else {
d.fixed = node;
mark(d, true);
if (unused && d.references.length == 1) {
d.single_use = d.scope === d.references[0].scope
|| node.is_constant_expression(d.references[0].scope);
}
}
var save_ids = safe_ids;
safe_ids = Object.create(null);
@@ -542,6 +552,7 @@ merge(Compressor.prototype, {
}
return true;
}
return def.fixed instanceof AST_Defun;
}
function safe_to_assign(def, value) {
@@ -580,7 +591,10 @@ merge(Compressor.prototype, {
}
function is_immutable(value) {
return value && (value.is_constant() || value instanceof AST_Lambda);
if (!value) return false;
return value.is_constant()
|| value instanceof AST_Lambda
|| value instanceof AST_This;
}
function read_property(obj, key) {
@@ -608,7 +622,7 @@ merge(Compressor.prototype, {
|| !immutable
&& parent instanceof AST_Call
&& parent.expression === node
&& (!(value instanceof AST_Function) || value.contains_this())) {
&& (!(value instanceof AST_Function) || value.contains_this(parent))) {
return true;
} else if (parent instanceof AST_Array || parent instanceof AST_Object) {
return is_modified(parent, parent, level + 1);
@@ -848,6 +862,7 @@ merge(Compressor.prototype, {
function collapse(statements, compressor) {
var scope = compressor.find_parent(AST_Scope).get_defun_scope();
if (scope.uses_eval || scope.uses_with) return statements;
var args;
var candidates = [];
var stat_index = statements.length;
while (--stat_index >= 0) {
@@ -868,7 +883,7 @@ merge(Compressor.prototype, {
var one_off = lhs instanceof AST_Symbol && lhs.definition().references.length == 1;
var side_effects = value_has_side_effects(candidate);
var hit = candidate.name instanceof AST_SymbolFunarg;
var abort = false, replaced = false;
var abort = false, replaced = false, can_replace = !args || !hit;
var tt = new TreeTransformer(function(node, descend) {
if (abort) return node;
// Skip nodes before `candidate` as quickly as possible
@@ -895,7 +910,8 @@ merge(Compressor.prototype, {
return node;
}
// Replace variable with assignment when found
if (!(node instanceof AST_SymbolDeclaration)
if (can_replace
&& !(node instanceof AST_SymbolDeclaration)
&& !is_lhs(node, parent)
&& lhs.equivalent_to(node)) {
CHANGED = replaced = abort = true;
@@ -946,6 +962,12 @@ merge(Compressor.prototype, {
// Skip (non-executed) functions and (leading) default case in switch statements
if (node instanceof AST_Default || node instanceof AST_Scope) return node;
});
if (!can_replace) {
for (var j = compressor.self().argnames.lastIndexOf(candidate.__name || candidate.name) + 1; j < args.length; j++) {
args[j].transform(tt);
}
can_replace = true;
}
for (var i = stat_index; !abort && i < statements.length; i++) {
statements[i].transform(tt);
}
@@ -991,9 +1013,16 @@ merge(Compressor.prototype, {
})) {
var fn_strict = compressor.has_directive("use strict");
if (fn_strict && fn.body.indexOf(fn_strict) < 0) fn_strict = false;
var len = fn.argnames.length;
args = iife.args.slice(len);
var names = Object.create(null);
for (var i = fn.argnames.length; --i >= 0;) {
for (var i = len; --i >= 0;) {
var sym = fn.argnames[i];
var arg = iife.args[i];
args.unshift(make_node(AST_VarDef, sym, {
name: sym,
value: arg
}));
if (sym.name in names) continue;
names[sym.name] = true;
if (sym instanceof AST_Expansion) {
@@ -1007,9 +1036,9 @@ merge(Compressor.prototype, {
elements: elements
})
}));
candidates[0].__name = sym;
}
} else {
var arg = iife.args[i];
if (!arg) arg = make_node(AST_Undefined, sym).transform(compressor);
else if (has_overlapping_symbol(fn, arg, fn_strict)) arg = null;
if (arg) candidates.unshift(make_node(AST_VarDef, sym, {
@@ -2265,18 +2294,22 @@ merge(Compressor.prototype, {
}
def(AST_Node, return_false);
def(AST_Constant, return_true);
def(AST_Function, function(){
def(AST_Lambda, function(scope){
var self = this;
var result = true;
self.walk(new TreeWalker(function(node) {
if (!result) return true;
if (node instanceof AST_SymbolRef) {
var def = node.definition();
if (self.enclosed.indexOf(def) >= 0
&& self.variables.get(def.name) !== def) {
if (member(def, self.enclosed)
&& !self.variables.has(def.name)) {
if (scope) {
var scope_def = scope.find_variable(node);
if (def.undeclared ? !scope_def : scope_def === def) return true;
}
result = false;
return true;
}
return true;
}
}));
return result;
@@ -2439,8 +2472,11 @@ merge(Compressor.prototype, {
});
return true;
}
if (assign_as_unused(node) instanceof AST_SymbolRef && scope === self
&& !is_ref_of(node.left, AST_SymbolBlockDeclaration)) {
var sym;
if (scope === self
&& (sym = assign_as_unused(node)) instanceof AST_SymbolRef
&& !is_ref_of(node.left, AST_SymbolBlockDeclaration)
&& self.variables.get(sym.name) === sym.definition()) {
if (node instanceof AST_Assign) node.right.walk(tw);
return true;
}
@@ -2526,9 +2562,11 @@ merge(Compressor.prototype, {
}
}
if ((node instanceof AST_Defun || node instanceof AST_DefClass) && node !== self) {
var keep = (node.name.definition().id in in_use_ids) || !drop_funcs && node.name.definition().global;
var def = node.name.definition();
var keep = (def.id in in_use_ids) || !drop_funcs && def.global;
if (!keep) {
compressor[node.name.unreferenced() ? "warn" : "info"]("Dropping unused function {name} [{file}:{line},{col}]", template(node.name));
drop_decl(def, node.name);
return make_node(AST_EmptyStatement, node);
}
return node;
@@ -2553,7 +2591,7 @@ merge(Compressor.prototype, {
if (var_defs.length > 1 && !def.value) {
compressor.warn("Dropping duplicated definition of variable {name} [{file}:{line},{col}]", template(def.name));
remove(var_defs, def);
remove(sym.orig, def.name);
drop_decl(sym, def.name);
return;
}
}
@@ -2586,7 +2624,7 @@ merge(Compressor.prototype, {
} else {
compressor[def.name.unreferenced() ? "warn" : "info"]("Dropping unused variable {name} [{file}:{line},{col}]", template(def.name));
}
remove(sym.orig, def.name);
drop_decl(sym, def.name);
}
});
if (head.length == 0 && tail.length == 1 && tail[0].name instanceof AST_SymbolVar) {
@@ -2595,7 +2633,7 @@ merge(Compressor.prototype, {
var def = tail.pop();
compressor.warn("Converting duplicated definition of variable {name} to assignment [{file}:{line},{col}]", template(def.name));
remove(var_defs, def);
remove(def.name.definition().orig, def.name);
drop_decl(def.name.definition(), def.name);
side_effects.unshift(make_node(AST_Assign, def, {
operator: "=",
left: make_node(AST_SymbolRef, def.name, def.name),
@@ -2627,8 +2665,7 @@ merge(Compressor.prototype, {
var def = assign_as_unused(node);
if (def instanceof AST_SymbolRef
&& !((def = def.definition()).id in in_use_ids)
&& (drop_vars || !def.global)
&& self.variables.get(def.name) === def) {
&& (drop_vars || !def.global)) {
if (node instanceof AST_Assign) {
return maintain_this_binding(parent, node, node.right.transform(tt));
}
@@ -2685,6 +2722,14 @@ merge(Compressor.prototype, {
col : sym.start.col
};
}
function drop_decl(def, decl) {
remove(def.orig, decl);
if (!def.orig.length) {
def.scope.functions.del(def.name);
def.scope.variables.del(def.name);
}
}
}
);
self.transform(tt);
@@ -4456,46 +4501,53 @@ merge(Compressor.prototype, {
if (compressor.option("unused")
&& fixed
&& d.references.length == 1
&& (d.single_use || is_func_expr(fixed)
&& !(d.scope.uses_arguments && d.orig[0] instanceof AST_SymbolFunarg)
&& !d.scope.uses_eval
&& compressor.find_parent(AST_Scope) === fixed.parent_scope)) {
&& d.single_use) {
var value = fixed.optimize(compressor);
return value === fixed ? fixed.clone(true) : value;
}
if (compressor.option("evaluate") && fixed) {
if (d.should_replace === undefined) {
var init = fixed.evaluate(compressor);
if (init !== fixed && (compressor.option("unsafe_regexp") || !(init instanceof RegExp))) {
init = make_node_from_constant(init, fixed);
var value_length = init.optimize(compressor).print_to_string().length;
var fn;
if (has_symbol_ref(fixed)) {
fn = function() {
var result = init.optimize(compressor);
return result === init ? result.clone(true) : result;
};
} else {
value_length = Math.min(value_length, fixed.print_to_string().length);
fn = function() {
var result = best_of_expression(init.optimize(compressor), fixed);
return result === init || result === fixed ? result.clone(true) : result;
};
}
var name_length = d.name.length;
var overhead = 0;
if (compressor.option("unused") && !compressor.exposed(d)) {
overhead = (name_length + 2 + value_length) / d.references.length;
}
d.should_replace = value_length <= name_length + overhead ? fn : false;
} else {
d.should_replace = false;
if (fixed && d.should_replace === undefined) {
var init;
if (fixed instanceof AST_This) {
if (!(d.orig[0] instanceof AST_SymbolFunarg)
&& all(d.references, function(ref) {
return d.scope === ref.scope;
})) {
init = fixed;
}
} else {
var ev = fixed.evaluate(compressor);
if (ev !== fixed && (compressor.option("unsafe_regexp") || !(ev instanceof RegExp))) {
init = make_node_from_constant(ev, fixed);
}
}
if (d.should_replace) {
return d.should_replace();
if (init) {
var value_length = init.optimize(compressor).print_to_string().length;
var fn;
if (has_symbol_ref(fixed)) {
fn = function() {
var result = init.optimize(compressor);
return result === init ? result.clone(true) : result;
};
} else {
value_length = Math.min(value_length, fixed.print_to_string().length);
fn = function() {
var result = best_of_expression(init.optimize(compressor), fixed);
return result === init || result === fixed ? result.clone(true) : result;
};
}
var name_length = d.name.length;
var overhead = 0;
if (compressor.option("unused") && !compressor.exposed(d)) {
overhead = (name_length + 2 + value_length) / d.references.length;
}
d.should_replace = value_length <= name_length + overhead ? fn : false;
} else {
d.should_replace = false;
}
}
if (d.should_replace) {
return d.should_replace();
}
}
return self;
@@ -4832,11 +4884,11 @@ merge(Compressor.prototype, {
}
}
if (is_lhs(self, compressor.parent())) return self;
if (compressor.option("properties") && key !== prop) {
var node = self.flatten_object(property, compressor);
if (node) {
expr = self.expression = node.expression;
prop = self.property = node.property;
if (key !== prop) {
var sub = self.flatten_object(property, compressor);
if (sub) {
expr = self.expression = sub.expression;
prop = self.property = sub.property;
}
}
if (compressor.option("properties") && compressor.option("side_effects")
@@ -4882,7 +4934,8 @@ merge(Compressor.prototype, {
return self;
});
AST_Lambda.DEFMETHOD("contains_this", function() {
AST_Lambda.DEFMETHOD("contains_this", function(grandparent) {
if (grandparent instanceof AST_New) return false;
var result;
var self = this;
self.walk(new TreeWalker(function(node) {
@@ -4894,6 +4947,7 @@ merge(Compressor.prototype, {
});
AST_PropAccess.DEFMETHOD("flatten_object", function(key, compressor) {
if (!compressor.option("properties")) return;
var arrows = compressor.option("unsafe_arrows") && compressor.option("ecma") >= 6;
var expr = this.expression;
if (expr instanceof AST_Object) {
@@ -4907,7 +4961,7 @@ merge(Compressor.prototype, {
})) break;
var value = prop.value;
if ((value instanceof AST_Accessor || value instanceof AST_Function)
&& value.contains_this()) break;
&& value.contains_this(compressor.parent())) break;
return make_node(AST_Sub, this, {
expression: make_node(AST_Array, expr, {
elements: props.map(function(prop) {
@@ -4957,10 +5011,8 @@ merge(Compressor.prototype, {
}
}
if (is_lhs(self, compressor.parent())) return self;
if (compressor.option("properties")) {
var node = self.flatten_object(self.property, compressor);
if (node) return node.optimize(compressor);
}
var sub = self.flatten_object(self.property, compressor);
if (sub) return sub.optimize(compressor);
var ev = self.evaluate(compressor);
if (ev !== self) {
ev = make_node_from_constant(ev, self).optimize(compressor);