Merge branch 'master' into harmony-2.8.0

lib/compress.js

@@ -1407,9 +1407,7 @@ merge(Compressor.prototype, {
             && (comments = this.start.comments_before)
             && comments.length
             && /[@#]__PURE__/.test((last_comment = comments[comments.length - 1]).value)) {
-            compressor.warn("Dropping __PURE__ call [{file}:{line},{col}]", this.start);
+            pure = last_comment;
-            last_comment.value = last_comment.value.replace(/[@#]__PURE__/g, ' ');
-            pure = true;
         }
         return this.pure = pure;
     });
@@ -1776,8 +1774,7 @@ merge(Compressor.prototype, {
                                 line : def.name.start.line,
                                 col  : def.name.start.col
                             };
-                            if (def.value && def.value.has_side_effects(compressor)) {
+                            if (def.value && (def._unused_side_effects = def.value.drop_side_effect_free(compressor))) {
-                                def._unused_side_effects = true;
                                 compressor.warn("Side effects in initialization of unused variable {name} [{file}:{line},{col}]", w);
                                 return true;
                             }
@@ -1797,7 +1794,7 @@ merge(Compressor.prototype, {
                         for (var i = 0; i < def.length;) {
                             var x = def[i];
                             if (x._unused_side_effects) {
-                                side_effects.push(x.value);
+                                side_effects.push(x._unused_side_effects);
                                 def.splice(i, 1);
                             } else {
                                 if (side_effects.length > 0) {
@@ -2040,6 +2037,10 @@ merge(Compressor.prototype, {
         def(AST_This, return_null);
         def(AST_Call, function(compressor, first_in_statement){
             if (!this.has_pure_annotation(compressor) && compressor.pure_funcs(this)) return this;
+            if (this.pure) {
+                compressor.warn("Dropping __PURE__ call [{file}:{line},{col}]", this.start);
+                this.pure.value = this.pure.value.replace(/[@#]__PURE__/g, ' ');
+            }
             var args = trim(this.args, compressor, first_in_statement);
             return args && AST_Seq.from_array(args);
         });
@@ -2091,8 +2092,17 @@ merge(Compressor.prototype, {
               case "typeof":
                 if (this.expression instanceof AST_SymbolRef) return null;
               default:
-                if (first_in_statement && is_iife_call(this.expression)) return this;
+                var expression = this.expression.drop_side_effect_free(compressor, first_in_statement);
-                return this.expression.drop_side_effect_free(compressor, first_in_statement);
+                if (first_in_statement
+                    && this instanceof AST_UnaryPrefix
+                    && is_iife_call(expression)) {
+                    if (expression === this.expression && this.operator.length === 1) return this;
+                    return make_node(AST_UnaryPrefix, this, {
+                        operator: this.operator.length === 1 ? this.operator : "!",
+                        expression: expression
+                    });
+                }
+                return expression;
             }
         });
         def(AST_SymbolRef, function() {
@@ -2140,10 +2150,6 @@ merge(Compressor.prototype, {
     OPT(AST_SimpleStatement, function(self, compressor){
         if (compressor.option("side_effects")) {
             var body = self.body;
-            if (!body.has_side_effects(compressor)) {
-                compressor.warn("Dropping side-effect-free statement [{file}:{line},{col}]", self.start);
-                return make_node(AST_EmptyStatement, self);
-            }
             var node = body.drop_side_effect_free(compressor, true);
             if (!node) {
                 compressor.warn("Dropping side-effect-free statement [{file}:{line},{col}]", self.start);
@@ -2780,17 +2786,10 @@ merge(Compressor.prototype, {
                 }
             }
             if (!self.car.has_side_effects(compressor)
-                && !self.cdr.has_side_effects(compressor)
                 && self.car.equivalent_to(self.cdr)) {
                 return self.car;
             }
         }
-        if (self.cdr instanceof AST_UnaryPrefix
-            && self.cdr.operator == "void"
-            && !self.cdr.expression.has_side_effects(compressor)) {
-            self.cdr.expression = self.car;
-            return self.cdr;
-        }
         if (self.cdr instanceof AST_Undefined) {
             return make_node(AST_UnaryPrefix, self, {
                 operator   : "void",
@@ -2819,8 +2818,20 @@ merge(Compressor.prototype, {
     });
 
     OPT(AST_UnaryPrefix, function(self, compressor){
-        self = self.lift_sequences(compressor);
+        var seq = self.lift_sequences(compressor);
+        if (seq !== self) {
+            return seq;
+        }
         var e = self.expression;
+        if (compressor.option("side_effects") && self.operator == "void") {
+            e = e.drop_side_effect_free(compressor);
+            if (e) {
+                self.expression = e;
+                return self;
+            } else {
+                return make_node(AST_Undefined, self);
+            }
+        }
         if (compressor.option("booleans") && compressor.in_boolean_context()) {
             switch (self.operator) {
               case "!":
@@ -2837,13 +2848,10 @@ merge(Compressor.prototype, {
                 // typeof always returns a non-empty string, thus it's
                 // always true in booleans
                 compressor.warn("Boolean expression always true [{file}:{line},{col}]", self.start);
-                if (self.expression.has_side_effects(compressor)) {
+                return make_node(AST_Seq, self, {
-                    return make_node(AST_Seq, self, {
+                    car: e,
-                        car: self.expression,
+                    cdr: make_node(AST_True, self)
-                        cdr: make_node(AST_True, self)
+                }).optimize(compressor);
-                    });
-                }
-                return make_node(AST_True, self);
             }
         }
         return self.evaluate(compressor)[0];
@@ -2973,13 +2981,10 @@ merge(Compressor.prototype, {
             var rr = self.right.evaluate(compressor);
             if ((ll.length > 1 && !ll[1]) || (rr.length > 1 && !rr[1])) {
                 compressor.warn("Boolean && always false [{file}:{line},{col}]", self.start);
-                if (self.left.has_side_effects(compressor)) {
+                return make_node(AST_Seq, self, {
-                    return make_node(AST_Seq, self, {
+                    car: self.left,
-                        car: self.left,
+                    cdr: make_node(AST_False)
-                        cdr: make_node(AST_False)
+                }).optimize(compressor);
-                    }).optimize(compressor);
-                }
-                return make_node(AST_False, self);
             }
             if (ll.length > 1 && ll[1]) {
                 return rr[0];
@@ -2993,13 +2998,10 @@ merge(Compressor.prototype, {
             var rr = self.right.evaluate(compressor);
             if ((ll.length > 1 && ll[1]) || (rr.length > 1 && rr[1])) {
                 compressor.warn("Boolean || always true [{file}:{line},{col}]", self.start);
-                if (self.left.has_side_effects(compressor)) {
+                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)
+                }).optimize(compressor);
-                    }).optimize(compressor);
-                }
-                return make_node(AST_True, self);
             }
             if (ll.length > 1 && !ll[1]) {
                 return rr[0];
@@ -3011,10 +3013,19 @@ merge(Compressor.prototype, {
           case "+":
             var ll = self.left.evaluate(compressor);
             var rr = self.right.evaluate(compressor);
-            if ((ll.length > 1 && ll[0] instanceof AST_String && ll[1] && !self.right.has_side_effects(compressor)) ||
+            if (ll.length > 1 && ll[0] instanceof AST_String && ll[1]) {
-                (rr.length > 1 && rr[0] instanceof AST_String && rr[1] && !self.left.has_side_effects(compressor))) {
                 compressor.warn("+ in boolean context always true [{file}:{line},{col}]", self.start);
-                return make_node(AST_True, self);
+                return make_node(AST_Seq, self, {
+                    car: self.right,
+                    cdr: make_node(AST_True, self)
+                }).optimize(compressor);
+            }
+            if (rr.length > 1 && rr[0] instanceof AST_String && rr[1]) {
+                compressor.warn("+ in boolean context always true [{file}:{line},{col}]", self.start);
+                return make_node(AST_Seq, self, {
+                    car: self.left,
+                    cdr: make_node(AST_True, self)
+                }).optimize(compressor);
             }
             break;
         }
@@ -3280,7 +3291,8 @@ merge(Compressor.prototype, {
             && alternative instanceof AST_Assign
             && consequent.operator == alternative.operator
             && consequent.left.equivalent_to(alternative.left)
-            && !consequent.left.has_side_effects(compressor)
+            && (!consequent.left.has_side_effects(compressor)
+                || !self.condition.has_side_effects(compressor))
            ) {
             /*
              * Stuff like this:
@@ -3298,25 +3310,19 @@ merge(Compressor.prototype, {
                 })
             });
         }
+        // x ? y(a) : y(b) --> y(x ? a : b)
         if (consequent instanceof AST_Call
             && alternative.TYPE === consequent.TYPE
-            && consequent.args.length == alternative.args.length
+            && consequent.args.length == 1
-            && !consequent.expression.has_side_effects(compressor)
+            && alternative.args.length == 1
-            && consequent.expression.equivalent_to(alternative.expression)) {
+            && consequent.expression.equivalent_to(alternative.expression)
-            if (consequent.args.length == 0) {
+            && !consequent.expression.has_side_effects(compressor)) {
-                return make_node(AST_Seq, self, {
+            consequent.args[0] = make_node(AST_Conditional, self, {
-                    car: self.condition,
+                condition: self.condition,
-                    cdr: consequent
+                consequent: consequent.args[0],
-                });
+                alternative: alternative.args[0]
-            }
+            });
-            if (consequent.args.length == 1) {
+            return consequent;
-                consequent.args[0] = make_node(AST_Conditional, self, {
-                    condition: self.condition,
-                    consequent: consequent.args[0],
-                    alternative: alternative.args[0]
-                });
-                return consequent;
-            }
         }
         // x?y?z:a:a --> x&&y?z:a
         if (consequent instanceof AST_Conditional
@@ -3331,16 +3337,12 @@ merge(Compressor.prototype, {
                 alternative: alternative
             });
         }
-        // y?1:1 --> 1
+        // x ? y : y --> x, y
-        if (consequent.is_constant()
+        if (consequent.equivalent_to(alternative)) {
-            && alternative.is_constant()
+            return make_node(AST_Seq, self, {
-            && consequent.equivalent_to(alternative)) {
+                car: self.condition,
-            var consequent_value = consequent.evaluate(compressor)[0];
+                cdr: consequent
-            if (self.condition.has_side_effects(compressor)) {
+            }).optimize(compressor);
-                return AST_Seq.from_array([self.condition, consequent_value]);
-            } else {
-                return consequent_value;
-            }
         }
 
         if (is_true(self.consequent)) {
@@ -3499,8 +3501,12 @@ merge(Compressor.prototype, {
     });
 
     function literals_in_boolean_context(self, compressor) {
-        if (compressor.option("booleans") && compressor.in_boolean_context() && !self.has_side_effects(compressor)) {
+        if (compressor.option("booleans") && compressor.in_boolean_context()) {
-            return make_node(AST_True, self);
+            var best = first_in_statement(compressor) ? best_of_statement : best_of;
+            return best(self, make_node(AST_Seq, self, {
+                car: self,
+                cdr: make_node(AST_True, self)
+            }).optimize(compressor));
         }
         return self;
     };

test/compress/conditionals.js

@@ -50,7 +50,8 @@ ifs_3_should_warn: {
         conditionals : true,
         dead_code    : true,
         evaluate     : true,
-        booleans     : true
+        booleans     : true,
+        side_effects : true,
     };
     input: {
         var x, y;
@@ -135,16 +136,28 @@ ifs_6: {
         comparisons: true
     };
     input: {
-        var x;
+        var x, y;
         if (!foo && !bar && !baz && !boo) {
             x = 10;
         } else {
             x = 20;
         }
+        if (y) {
+            x[foo] = 10;
+        } else {
+            x[foo] = 20;
+        }
+        if (foo) {
+            x[bar] = 10;
+        } else {
+            x[bar] = 20;
+        }
     }
     expect: {
-        var x;
+        var x, y;
         x = foo || bar || baz || boo ? 20 : 10;
+        x[foo] = y ? 10 : 20;
+        foo ? x[bar] = 10 : x[bar] = 20;
     }
 }
 
@@ -159,10 +172,16 @@ cond_1: {
         } else {
             do_something(y);
         }
+        if (some_condition()) {
+            side_effects(x);
+        } else {
+            side_effects(y);
+        }
     }
     expect: {
         var do_something;
         do_something(some_condition() ? x : y);
+        some_condition() ? side_effects(x) : side_effects(y);
     }
 }
 
@@ -213,10 +232,16 @@ cond_4: {
         } else {
             do_something();
         }
+        if (some_condition()) {
+            side_effects();
+        } else {
+            side_effects();
+        }
     }
     expect: {
         var do_something;
         some_condition(), do_something();
+        some_condition(), side_effects();
     }
 }
 
@@ -250,7 +275,8 @@ cond_5: {
 cond_7: {
     options = {
         conditionals: true,
-        evaluate    : true
+        evaluate    : true,
+        side_effects: true,
     };
     input: {
         var x, y, z, a, b;
@@ -714,6 +740,7 @@ issue_1154: {
         conditionals: true,
         evaluate    : true,
         booleans    : true,
+        side_effects: true,
     };
     input: {
         function f1(x) { return x ? -1 : -1; }
@@ -742,7 +769,7 @@ issue_1154: {
         function g2() { return g(), 2; }
         function g3() { return g(), -4; }
         function g4() { return g(), !1; }
-        function g5() { return g(), void 0; }
+        function g5() { return void g(); }
         function g6() { return g(), "number"; }
     }
 }
@@ -750,7 +777,8 @@ issue_1154: {
 no_evaluate: {
     options = {
         conditionals: true,
-        evaluate    : false
+        evaluate    : false,
+        side_effects: true,
     }
     input: {
         function f(b) {

test/compress/dead-code.js

@@ -64,7 +64,8 @@ dead_code_constant_boolean_should_warn_more: {
         loops        : true,
         booleans     : true,
         conditionals : true,
-        evaluate     : true
+        evaluate     : true,
+        side_effects : true,
     };
     input: {
         while (!((foo && bar) || (x + "0"))) {

test/compress/evaluate.js

@@ -718,25 +718,35 @@ in_boolean_context: {
     options = {
         booleans: true,
         evaluate: true,
+        sequences: true,
+        side_effects: true,
     }
     input: {
-        !42;
+        console.log(
-        !"foo";
+            !42,
-        ![1, 2];
+            !"foo",
-        !/foo/;
+            ![1, 2],
-        !b(42);
+            !/foo/,
-        !b("foo");
+            !b(42),
-        !b([1, 2]);
+            !b("foo"),
-        !b(/foo/);
+            !b([1, 2]),
+            !b(/foo/),
+            ![1, foo()],
+            ![1, foo(), 2]
+        );
     }
     expect: {
-        !1;
+        console.log(
-        !1;
+            !1,
-        !1;
+            !1,
-        !1;
+            !1,
-        !b(42);
+            !1,
-        !b("foo");
+            !b(42),
-        !b([1, 2]);
+            !b("foo"),
-        !b(/foo/);
+            !b([1, 2]),
+            !b(/foo/),
+            ![1, foo()],
+            (foo(), !1)
+        );
     }
 }

test/compress/issue-1261.js

@@ -116,3 +116,61 @@ pure_function_calls_toplevel: {
         "WARN: Dropping unused variable iife1 [test/compress/issue-1261.js:84,12]",
     ]
 }
+
+should_warn: {
+    options = {
+        booleans: true,
+        conditionals: true,
+        evaluate: true,
+        side_effects: true,
+    }
+    input: {
+        /* @__PURE__ */(function(){x})(), void/* @__PURE__ */(function(){y})();
+        /* @__PURE__ */(function(){x})() || true ? foo() : bar();
+        true || /* @__PURE__ */(function(){y})() ? foo() : bar();
+        /* @__PURE__ */(function(){x})() && false ? foo() : bar();
+        false && /* @__PURE__ */(function(){y})() ? foo() : bar();
+        /* @__PURE__ */(function(){x})() + "foo" ? bar() : baz();
+        "foo" + /* @__PURE__ */(function(){y})() ? bar() : baz();
+        /* @__PURE__ */(function(){x})() ? foo() : foo();
+        [/* @__PURE__ */(function(){x})()] ? foo() : bar();
+        !{ foo: /* @__PURE__ */(function(){x})() } ? bar() : baz();
+    }
+    expect: {
+        foo();
+        foo();
+        bar();
+        bar();
+        bar();
+        bar();
+        foo();
+        foo();
+        baz();
+    }
+    expect_warnings: [
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:128,61]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:128,23]",
+        "WARN: Dropping side-effect-free statement [test/compress/issue-1261.js:128,23]",
+        "WARN: Boolean || always true [test/compress/issue-1261.js:129,23]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:129,23]",
+        "WARN: Condition always true [test/compress/issue-1261.js:129,23]",
+        "WARN: Boolean || always true [test/compress/issue-1261.js:130,8]",
+        "WARN: Condition always true [test/compress/issue-1261.js:130,8]",
+        "WARN: Boolean && always false [test/compress/issue-1261.js:131,23]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:131,23]",
+        "WARN: Condition always false [test/compress/issue-1261.js:131,23]",
+        "WARN: Boolean && always false [test/compress/issue-1261.js:132,8]",
+        "WARN: Condition always false [test/compress/issue-1261.js:132,8]",
+        "WARN: + in boolean context always true [test/compress/issue-1261.js:133,23]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:133,23]",
+        "WARN: Condition always true [test/compress/issue-1261.js:133,23]",
+        "WARN: + in boolean context always true [test/compress/issue-1261.js:134,8]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:134,31]",
+        "WARN: Condition always true [test/compress/issue-1261.js:134,8]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:135,23]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:136,24]",
+        "WARN: Condition always true [test/compress/issue-1261.js:136,8]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:137,31]",
+        "WARN: Condition always false [test/compress/issue-1261.js:137,8]",
+    ]
+}

test/compress/issue-1275.js

@@ -35,7 +35,7 @@ string_plus_optimization: {
                 throw "nope";
             }
             try {
-                console.log('0' + throwing_function() ? "yes" : "no");
+                console.log((throwing_function(), "yes"));
             } catch (ex) {
                 console.log(ex);
             }

test/compress/typeof.js

@@ -29,6 +29,7 @@ typeof_in_boolean_context: {
         booleans     : true,
         evaluate     : true,
         conditionals : true,
+        side_effects : true,
     };
     input: {
         function f1(x) { return typeof x ? "yes" : "no"; }
@@ -36,12 +37,14 @@ typeof_in_boolean_context: {
         typeof 0 ? foo() : bar();
         !typeof console.log(1);
         var a = !typeof console.log(2);
+        if (typeof (1 + foo()));
     }
     expect: {
         function f1(x) { return "yes"; }
         function f2() { return g(), "Yes"; }
         foo();
-        !(console.log(1), !0);
+        console.log(1);
         var a = !(console.log(2), !0);
+        foo();
     }
 }

test/mocha/minify.js

@@ -154,6 +154,17 @@ describe("minify", function() {
             var code = result.code;
             assert.strictEqual(code, "//  comment1   comment2\nbar();");
         });
+        it("should not drop #__PURE__ hint if function is retained", function() {
+            var result = Uglify.minify("var a = /*#__PURE__*/(function(){return 1})();", {
+                fromString: true,
+                output: {
+                    comments: "all",
+                    beautify: false,
+                }
+            });
+            var code = result.code;
+            assert.strictEqual(code, "var a=/*#__PURE__*/function(){return 1}();");
+        })
     });
 
     describe("JS_Parse_Error", function() {