extend inline (#2714)

- compress `function` with variables within loops
- restrict to `AST_Var` for better compatibility with ES6+
This commit is contained in:
Alex Lam S.L
2018-01-04 12:58:40 +08:00
committed by GitHub
parent c598a12af9
commit 9b58b54e2d
2 changed files with 40 additions and 25 deletions

View File

@@ -4109,7 +4109,7 @@ merge(Compressor.prototype, {
stat = null;
for (var i = 0; i < len; i++) {
var line = fn.body[i];
if (line instanceof AST_Definitions) {
if (line instanceof AST_Var) {
if (stat && !all(line.definitions, function(var_def) {
return !var_def.value;
})) {
@@ -4124,7 +4124,7 @@ merge(Compressor.prototype, {
return return_value(stat);
}
function can_inject_args(catches, defs, safe_to_inject) {
function can_inject_args(catches, safe_to_inject) {
for (var i = 0, len = fn.argnames.length; i < len; i++) {
var arg = fn.argnames[i];
if (arg.__unused) continue;
@@ -4143,7 +4143,7 @@ merge(Compressor.prototype, {
var len = fn.body.length;
for (var i = 0; i < len; i++) {
var stat = fn.body[i];
if (!(stat instanceof AST_Definitions)) continue;
if (!(stat instanceof AST_Var)) continue;
if (!safe_to_inject) return false;
for (var j = stat.definitions.length; --j >= 0;) {
var name = stat.definitions[j].name;
@@ -4152,6 +4152,7 @@ merge(Compressor.prototype, {
|| scope.var_names()[name.name]) {
return false;
}
if (in_loop) in_loop.push(name.definition());
}
}
return true;
@@ -4171,8 +4172,8 @@ merge(Compressor.prototype, {
} while (!(scope instanceof AST_Scope));
var safe_to_inject = !(scope instanceof AST_Toplevel) || compressor.toplevel.vars;
var inline = compressor.option("inline");
if (!can_inject_vars(catches, !in_loop && inline >= 3 && safe_to_inject)) return false;
if (!can_inject_args(catches, in_loop, inline >= 2 && safe_to_inject)) return false;
if (!can_inject_vars(catches, inline >= 3 && safe_to_inject)) return false;
if (!can_inject_args(catches, inline >= 2 && safe_to_inject)) return false;
return !in_loop || in_loop.length == 0 || !is_reachable(fn, in_loop);
}
@@ -4181,13 +4182,13 @@ merge(Compressor.prototype, {
scope.var_names()[name.name] = true;
scope.variables.set(name.name, def);
scope.enclosed.push(def);
decls.push(make_node(AST_VarDef, name, {
decls.unshift(make_node(AST_VarDef, name, {
name: name,
value: null
}));
var sym = make_node(AST_SymbolRef, name, name);
def.references.push(sym);
if (value) expressions.push(make_node(AST_Assign, self, {
if (value) expressions.unshift(make_node(AST_Assign, self, {
operator: "=",
left: sym,
right: value
@@ -4195,11 +4196,15 @@ merge(Compressor.prototype, {
}
function flatten_args(decls, expressions) {
for (var len = fn.argnames.length, i = len; --i >= 0;) {
var len = fn.argnames.length;
for (var i = self.args.length; --i >= len;) {
expressions.unshift(self.args[i]);
}
for (i = len; --i >= 0;) {
var name = fn.argnames[i];
var value = self.args[i];
if (name.__unused || scope.var_names()[name.name]) {
if (value) expressions.push(value);
if (value) expressions.unshift(value);
} else {
var symbol = make_node(AST_SymbolVar, name, name);
name.definition().orig.push(symbol);
@@ -4207,30 +4212,38 @@ merge(Compressor.prototype, {
append_var(decls, expressions, symbol, value);
}
}
decls.reverse();
expressions.reverse();
for (i = len, len = self.args.length; i < len; i++) {
expressions.push(self.args[i]);
}
}
function flatten_body(decls, expressions) {
for (i = 0, len = fn.body.length; i < len; i++) {
function flatten_vars(decls, expressions) {
if (in_loop) in_loop.length = 0;
for (var i = fn.body.length; --i >= 0;) {
var stat = fn.body[i];
if (stat instanceof AST_Definitions) {
stat.definitions.forEach(function(var_def) {
append_var(decls, expressions, var_def.name, var_def.value);
});
if (!(stat instanceof AST_Var)) continue;
for (var j = stat.definitions.length; --j >= 0;) {
var var_def = stat.definitions[j];
var name = var_def.name;
append_var(decls, expressions, name, var_def.value);
if (in_loop) {
var def = name.definition();
var sym = make_node(AST_SymbolRef, name, name);
def.references.push(sym);
in_loop.unshift(make_node(AST_Assign, var_def, {
operator: "=",
left: sym,
right: make_node(AST_Undefined, name)
}));
}
}
}
expressions.push(value);
if (in_loop) [].unshift.apply(expressions, in_loop);
}
function flatten_fn() {
var decls = [];
var expressions = [];
flatten_vars(decls, expressions);
flatten_args(decls, expressions);
flatten_body(decls, expressions);
expressions.push(value);
if (decls.length) {
i = scope.body.indexOf(compressor.parent(level - 1)) + 1;
scope.body.splice(i, 0, make_node(AST_Var, fn, {

View File

@@ -1299,6 +1299,7 @@ issue_2630_2: {
passes: 2,
reduce_vars: true,
sequences: true,
side_effects: true,
unused: true,
}
input: {
@@ -1905,6 +1906,7 @@ inline_true: {
use_before_init_in_loop: {
options = {
inline: true,
side_effects: true,
toplevel: true,
}
input: {
@@ -1918,9 +1920,9 @@ use_before_init_in_loop: {
}
expect: {
var a = "PASS";
for (var b = 2; --b >= 0;) (function() {
var c = (c && (a = "FAIL"), 1);
})();
for (var b = 2; --b >= 0;)
c = void 0, c = (c && (a = "FAIL"), 1);
var c;
console.log(a);
}
expect_stdout: "PASS"