implement name generation & collision avoidance

lib/compress.js

@@ -2689,6 +2689,10 @@ merge(Compressor.prototype, {
         var self = this;
         if (!compressor.option("hoist_props") || compressor.has_directive("use asm")) return self;
         var defs_by_id = Object.create(null);
+        var var_names = Object.create(null);
+        self.enclosed.forEach(function(def) {
+            var_names[def.name] = true;
+        });
         var tt = new TreeTransformer(function(node) {
             if (node instanceof AST_VarDef) {
                 var sym = node.name, def, value;
@@ -2699,31 +2703,13 @@ merge(Compressor.prototype, {
                     && (value = sym.fixed_value()) === node.value
                     && value instanceof AST_Object) {
                     var defs = new Dictionary();
-                    var assignments = [
+                    var assignments = [];
-                        make_node(AST_VarDef, node, {
-                            name: sym,
-                            value: make_node(AST_Object, value, {
-                                properties: []
-                            })
-                        })
-                    ];
                     value.properties.forEach(function(prop) {
-                        var key = make_node(sym.CTOR, sym, {
-                            name: make_node(AST_Sub, sym, {
-                                expression: sym,
-                                property: make_node(AST_String, prop, {
-                                    value: prop.key
-                                })
-                            }).print_to_string(),
-                            scope: self
-                        });
-                        defs.set(prop.key, self.def_variable(key));
                         assignments.push(make_node(AST_VarDef, node, {
-                            name: key,
+                            name: make_sym(prop.key),
                             value: prop.value
                         }));
                     });
-                    if (assignments.length == 1) return assignments[0];
                     defs_by_id[def.id] = defs;
                     return MAP.splice(assignments);
                 }
@@ -2739,10 +2725,25 @@ merge(Compressor.prototype, {
                         scope: node.expression.scope,
                         thedef: def
                     });
-                    def.references.push(sym);
+                    sym.reference({});
                     return sym;
                 }
             }
+
+            function make_sym(key) {
+                var prefix = sym.name + "_" + key.replace(/[^a-z_$]+/ig, "_");
+                var name = prefix;
+                for (var i = 0; var_names[name]; i++) name = prefix + "$" + i;
+                var new_var = make_node(sym.CTOR, sym, {
+                    name: name,
+                    scope: self
+                });
+                var def = self.def_variable(new_var);
+                defs.set(key, def);
+                self.enclosed.push(def);
+                var_names[name] = true;
+                return new_var;
+            }
         });
         return self.transform(tt);
     });

test/compress/hoist_props.js

@@ -7,9 +7,6 @@ issue_2377_1: {
         toplevel: true,
         unused: true,
     }
-    mangle = {
-        toplevel: true,
-    }
     input: {
         var obj = {
             foo: 1,
@@ -24,10 +21,10 @@ issue_2377_1: {
         console.log(obj.foo, obj.cube(3));
     }
     expect: {
-        var n = 1, o = function(n) {
+        var obj_foo = 1, obj_cube = function(x) {
-            return n * n * n;
+            return x * x * x;
         };
-        console.log(n, o(3));
+        console.log(obj_foo, obj_cube(3));
     }
     expect_stdout: "1 27"
 }
@@ -42,9 +39,6 @@ issue_2377_2: {
         toplevel: true,
         unused: true,
     }
-    mangle = {
-        toplevel: true,
-    }
     input: {
         var obj = {
             foo: 1,
@@ -59,8 +53,8 @@ issue_2377_2: {
         console.log(obj.foo, obj.cube(3));
     }
     expect: {
-        console.log(1, function(n) {
+        console.log(1, function(x) {
-            return n * n * n;
+            return x * x * x;
         }(3));
     }
     expect_stdout: "1 27"
@@ -76,9 +70,6 @@ issue_2377_3: {
         toplevel: true,
         unused: true,
     }
-    mangle = {
-        toplevel: true,
-    }
     input: {
         var obj = {
             foo: 1,
@@ -105,9 +96,6 @@ direct_access_1: {
         toplevel: true,
         unused: true,
     }
-    mangle = {
-        toplevel: true,
-    }
     input: {
         var a = 0;
         var obj = {
@@ -119,12 +107,12 @@ direct_access_1: {
     }
     expect: {
         var a = 0;
-        var o = {
+        var obj = {
             a: 1,
             b: 2,
         };
-        for (var r in o) a++;
+        for (var k in obj) a++;
-        console.log(a, o.a);
+        console.log(a, obj.a);
     }
     expect_stdout: "2 1"
 }
@@ -136,9 +124,6 @@ direct_access_2: {
         toplevel: true,
         unused: true,
     }
-    mangle = {
-        toplevel: true,
-    }
     input: {
         var o = { a: 1 };
         var f = function(k) {
@@ -147,9 +132,9 @@ direct_access_2: {
         console.log(f("a"));
     }
     expect: {
-        var n = { a: 1 };
+        var o = { a: 1 };
-        console.log(function(o) {
+        console.log(function(k) {
-            if (n[o]) return "PASS";
+            if (o[k]) return "PASS";
         }("a"));
     }
     expect_stdout: "PASS"
@@ -162,18 +147,15 @@ direct_access_3: {
         toplevel: true,
         unused: true,
     }
-    mangle = {
-        toplevel: true,
-    }
     input: {
         var o = { a: 1 };
         o.b;
         console.log(o.a);
     }
     expect: {
-        var a = { a: 1 };
+        var o = { a: 1 };
-        a.b;
+        o.b;
-        console.log(a.a);
+        console.log(o.a);
     }
     expect_stdout: "1"
 }
@@ -185,9 +167,6 @@ single_use: {
         toplevel: true,
         unused: true,
     }
-    mangle = {
-        toplevel: true,
-    }
     input: {
         var obj = {
             bar: function() {
@@ -204,3 +183,40 @@ single_use: {
         }.bar());
     }
 }
+
+name_collision: {
+    options = {
+        reduce_vars: true,
+        hoist_props: true,
+        toplevel: true,
+    }
+    input: {
+        var obj_foo = 1;
+        var obj_bar = 2;
+        function f() {
+            var obj = {
+                foo: 3,
+                bar: 4,
+                "b-r": 5,
+                "b+r": 6,
+                "b!r": 7,
+            };
+            console.log(obj_foo, obj.foo, obj.bar, obj["b-r"], obj["b+r"], obj["b!r"]);
+        }
+        f();
+    }
+    expect: {
+        var obj_foo = 1;
+        var obj_bar = 2;
+        function f() {
+            var obj_foo$0 = 3,
+                obj_bar = 4,
+                obj_b_r = 5,
+                obj_b_r$0 = 6,
+                obj_b_r$1 = 7;
+            console.log(obj_foo, obj_foo$0, obj_bar, obj_b_r, obj_b_r$0, obj_b_r$1);
+        }
+        f();
+    }
+    expect_stdout: "1 3 4 5 6 7"
+}