Add a method of dumping the AST

bin/uglifyjs

@@ -76,6 +76,7 @@ You need to pass an argument to this option to specify the name that your module
     .describe("name-cache", "File to hold mangled names mappings")
     .describe("pure-funcs", "List of functions that can be safely removed if their return value is not used")
     .describe("dump-spidermonkey-ast", "Dump SpiderMonkey AST to stdout.")
+    .describe("dump-ast", "Dump the AST instead of generating output")
 
     .alias("p", "prefix")
     .alias("o", "output")
@@ -130,6 +131,7 @@ You need to pass an argument to this option to specify the name that your module
     .boolean("bare-returns")
     .boolean("keep-fnames")
     .boolean("reserve-domprops")
+    .boolean("dump-ast")
 
     .wrap(80)
 
@@ -476,7 +478,8 @@ async.eachLimit(files, 1, function (file, cb) {
         print(JSON.stringify(TOPLEVEL.to_mozilla_ast(), null, 2));
     } else {
         time_it("generate", function(){
-            TOPLEVEL.print(output);
+            if (ARGS.dump_ast) output.print(TOPLEVEL.dump());
+            else TOPLEVEL.print(output);
         });
 
         output = output.get();

lib/ast.js

@@ -47,11 +47,24 @@ function DEFNODE(type, props, methods, base) {
     if (arguments.length < 4) base = AST_Node;
     if (!props) props = [];
     else props = props.split(/\s+/);
+    var dump_props = [];
+    props = props.map(function(prop){
+        if (/!$/.test(prop)) {
+            prop = prop.slice(0, -1);
+        } else {
+            dump_props.push(prop);
+        }
+        return prop;
+    });
     var self_props = props;
-    if (base && base.PROPS)
-        props = props.concat(base.PROPS);
-    var code = "return function AST_" + type + "(props){ if (props) { ";
-    for (var i = props.length; --i >= 0;) {
+    if (base) {
+        if (base.PROPS) props = props.concat(base.PROPS);
+        if (base.DUMP_PROPS) dump_props = dump_props.concat(base.DUMP_PROPS);
+    }
+    var code = "return function AST_" + type + "(props){";
+    if (type) { code += "this._class = 'AST_" + type + "';"; }
+    code += " if (props) { ";
+    for (var i = 0; i < props.length; ++i) {
         code += "this." + props[i] + " = props." + props[i] + ";";
     }
     var proto = base && new base;
@@ -66,6 +79,7 @@ function DEFNODE(type, props, methods, base) {
     if (base) base.SUBCLASSES.push(ctor);
     ctor.prototype.CTOR = ctor;
     ctor.PROPS = props || null;
+    ctor.DUMP_PROPS = dump_props.sort();
     ctor.SELF_PROPS = self_props;
     ctor.SUBCLASSES = [];
     if (type) {
@@ -88,7 +102,7 @@ function DEFNODE(type, props, methods, base) {
 var AST_Token = DEFNODE("Token", "type value line col pos endline endcol endpos nlb comments_before file raw", {
 }, null);
 
-var AST_Node = DEFNODE("Node", "start end", {
+var AST_Node = DEFNODE("Node", "start! end!", {
     clone: function() {
         return new this.CTOR(this);
     },
@@ -102,6 +116,9 @@ var AST_Node = DEFNODE("Node", "start end", {
     },
     walk: function(visitor) {
         return this._walk(visitor); // not sure the indirection will be any help
+    },
+    dump: function () {
+        return JSON.stringify(dump_internal(this), null, 2);
     }
 }, null);
 
@@ -121,7 +138,7 @@ var AST_Debugger = DEFNODE("Debugger", null, {
     $documentation: "Represents a debugger statement",
 }, AST_Statement);
 
-var AST_Directive = DEFNODE("Directive", "value scope quote", {
+var AST_Directive = DEFNODE("Directive", "value scope! quote", {
     $documentation: "Represents a directive, like \"use strict\";",
     $propdoc: {
         value: "[string] The value of this directive as a plain string (it's not an AST_String!)",
@@ -278,7 +295,7 @@ var AST_With = DEFNODE("With", "expression", {
 
 /* -----[ scope and functions ]----- */
 
-var AST_Scope = DEFNODE("Scope", "directives variables functions uses_with uses_eval parent_scope enclosed cname", {
+var AST_Scope = DEFNODE("Scope", "directives variables! functions! uses_with! uses_eval! parent_scope! enclosed! cname!", {
     $documentation: "Base class for all statements introducing a lexical scope",
     $propdoc: {
         directives: "[string*/S] an array of directives declared in this scope",
@@ -292,7 +309,7 @@ var AST_Scope = DEFNODE("Scope", "directives variables functions uses_with uses_
     },
 }, AST_Block);
 
-var AST_Toplevel = DEFNODE("Toplevel", "globals", {
+var AST_Toplevel = DEFNODE("Toplevel", "globals!", {
     $documentation: "The toplevel scope",
     $propdoc: {
         globals: "[Object/S] a map of name -> SymbolDef for all undeclared names",
@@ -789,7 +806,7 @@ var AST_ObjectGetter = DEFNODE("ObjectGetter", null, {
     $documentation: "An object getter property",
 }, AST_ObjectProperty);
 
-var AST_Symbol = DEFNODE("Symbol", "scope name thedef", {
+var AST_Symbol = DEFNODE("Symbol", "scope! name thedef!", {
     $propdoc: {
         name: "[string] name of this symbol",
         scope: "[AST_Scope/S] the current scope (not necessarily the definition scope)",

lib/utils.js

@@ -214,6 +214,27 @@ function set_intersection(a, b) {
     });
 };
 
+function dump_internal(val) {
+    if (val) {
+        if (typeof val.map == 'function') {
+            return val.filter(function (x) {
+                return x != null;
+            }).map(dump_internal);
+        }
+
+        if (val.CTOR) {
+            var out = {_class: val._class};
+            val.CTOR.DUMP_PROPS.forEach(function(prop){
+                if (val[prop] != null) {
+                    out[prop] = dump_internal(val[prop]);
+                }
+            });
+            return out;
+        }
+    }
+    return val;
+};
+
 // this function is taken from Acorn [1], written by Marijn Haverbeke
 // [1] https://github.com/marijnh/acorn
 function makePredicate(words) {