changeset 1222:984370b5de3b

8006996: Add a pretty printer that prints script source in nice form Reviewed-by: lagergren, hannesw
author sundar
date Thu, 19 Mar 2015 15:13:01 +0530
parents eaa136f2b489
children e2334bbe7644
files samples/prettyprinter.js
diffstat 1 files changed, 642 insertions(+), 0 deletions(-) [+]
line wrap: on
line diff
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/samples/prettyprinter.js	Thu Mar 19 15:13:01 2015 +0530
@@ -0,0 +1,642 @@
+/*
+ * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *   - Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *
+ *   - Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *
+ *   - Neither the name of Oracle nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+ * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/**
+ * This script is a AST pretty printer for ECMAScript. It uses
+ * Nashorn parser API to parser given script and uses tree visitor
+ * to pretty print the AST to stdout as a script string.
+ */
+
+var File = Java.type("java.io.File");
+var file = arguments.length == 0? new File(__FILE__) : new File(arguments[0]);
+if (! file.isFile()) {
+    print(arguments[0] + " is not a file");
+    exit(1);
+}
+
+// Java classes used
+var ArrayAccess = Java.type("jdk.nashorn.api.tree.ArrayAccessTree");
+var Block = Java.type("jdk.nashorn.api.tree.BlockTree");
+var FunctionDeclaration = Java.type("jdk.nashorn.api.tree.FunctionDeclarationTree");
+var FunctionExpression = Java.type("jdk.nashorn.api.tree.FunctionExpressionTree");
+var Identifier = Java.type("jdk.nashorn.api.tree.IdentifierTree");
+var Kind = Java.type("jdk.nashorn.api.tree.Tree.Kind");
+var MemberSelect = Java.type("jdk.nashorn.api.tree.MemberSelectTree");
+var ObjectLiteral = Java.type("jdk.nashorn.api.tree.ObjectLiteralTree");
+var Parser = Java.type("jdk.nashorn.api.tree.Parser");
+var SimpleTreeVisitor = Java.type("jdk.nashorn.api.tree.SimpleTreeVisitorES5_1");
+var System = Java.type("java.lang.System");
+
+// make a nashorn parser
+var parser = Parser.create("-scripting", "--const-as-var");
+
+// symbols for nashorn operators
+var operatorSymbols = {
+    POSTFIX_INCREMENT: "++", 
+    POSTFIX_DECREMENT: "--",
+    PREFIX_INCREMENT: "++", 
+    PREFIX_DECREMENT: "--",
+    UNARY_PLUS: "+",
+    UNARY_MINUS: "-",
+    BITWISE_COMPLEMENT: "~",
+    LOGICAL_COMPLEMENT: "!",
+    DELETE: "delete ",
+    TYPEOF: "typeof ",
+    VOID: "void ", 
+    COMMA: ",",
+    MULTIPLY: "*", 
+    DIVIDE: "/", 
+    REMINDER: "%", 
+    PLUS: "+",
+    MINUS: "-",
+    LEFT_SHIFT: "<<",
+    RIGHT_SHIFT: ">>",
+    UNSIGNED_RIGHT_SHIFT: ">>>",
+    LESS_THAN: "<",
+    GREATER_THAN: ">",
+    LESS_THAN_EQUAL: "<=",
+    GREATER_THAN_EQUAL: ">=", 
+    IN: "in", 
+    EQUAL_TO: "==",
+    NOT_EQUAL_TO: "!=",
+    STRICT_EQUAL_TO: "===",
+    STRICT_NOT_EQUAL_TO: "!==",
+    AND: "&",
+    XOR: "^",
+    OR: "|", 
+    CONDITIONAL_AND: "&&", 
+    CONDITIONAL_OR: "||",
+    MULTIPLY_ASSIGNMENT: "*=",
+    DIVIDE_ASSIGNMENT: "/=",
+    REMINDER_ASSIGNMENT: "%=",
+    PLUS_ASSIGNMENT: "+=",
+    MINUS_ASSIGNMENT: "-=",
+    LEFT_SHIFT_ASSIGNMENT: "<<=",
+    RIGHT_SHIFT_ASSIGNMENT: ">>=",
+    UNSIGNED_RIGHT_SHIFT_ASSIGNMENT: ">>>=",
+    AND_ASSIGNMENT: "&=",
+    XOR_ASSIGNMENT: "^=",
+    OR_ASSIGNMENT: "|="
+};
+
+function operatorOf(kind) {
+     var name = kind.name();
+     if (name in operatorSymbols) {
+         return operatorSymbols[name];
+     }
+     throw "invalid operator: " + name;
+}
+
+var gprint = print;
+
+function prettyPrint(file) {
+    var ast = parser.parse(file, gprint);
+    if (!ast) {
+        // failed to parse. don't print anything!
+        return;
+    }
+
+    // AST visitor
+    var visitor;
+    // current indent level
+    var indentLevel = 0;
+    var out = System.out;
+
+    function print(obj) {
+        out.print(String(obj));
+    }
+
+    function println(obj) {
+        obj?  out.println(String(obj)) : out.println();
+    }
+
+    // semicolon and end-of-line
+    function eol() {
+        println(";");
+    }
+
+    // print indentation - 4 spaces per level
+    function indent() {
+        for (var i = 0; i < indentLevel; i++) {
+            // 4 spaces per indent level
+            print("    ");
+        }
+    }
+
+    // escape string literals
+    function escapeString(str) {
+        // FIXME: incomplete, revisit again!
+        return str.replace(/[\\"']/g, '\\$&')
+    }
+
+    // print a single statement (could be a block too)
+    function printStatement(stat, extra, end) {
+        if (stat instanceof Block) {
+            println(" {");
+            printStatements(stat.statements, extra);
+            indent();
+            print('}');
+            typeof end != "undefined"? print(end) : println();
+        } else {
+            println();
+            indentLevel++;
+            try {
+                stat.accept(visitor, extra);
+            } finally {
+                indentLevel--;
+            }
+        }
+    }
+
+    // print a statement list
+    function printStatements(stats, extra) {
+        indentLevel++;
+        try {
+            for each (var stat in stats) {
+                stat.accept(visitor, extra);
+            }
+        } finally {
+            indentLevel--;
+        }
+    }
+
+    // function arguments, array literal elements.
+    function printCommaList(args, extra) {
+        var len = args.length;
+        for (var i = 0; i < len; i++) {
+            args[i].accept(visitor, extra);
+            if (i != len - 1) {
+                print(", ");
+            }
+        }
+    }
+
+    // print function declarations and expressions
+    function printFunction(func, extra, end) {
+        // extra lines around function declarations for clarity
+        var funcDecl = (func instanceof FunctionDeclaration);
+        if (funcDecl) {
+            println();
+            indent();
+        }
+        print("function ");
+        if (func.name) {
+            print(func.name);
+        }
+        printFunctionBody(func, extra, end);
+        if (funcDecl) {
+            println();
+        }
+    }
+
+    // print function declaration/expression body
+    function printFunctionBody(func, extra, end) {
+        print('(');
+        var params = func.parameters;
+        if (params) {
+            printCommaList(params);
+        }
+        print(')');
+        printStatement(func.body, extra, end);
+    }
+
+    // print object literal property
+    function printProperty(node, extra, comma) {
+        var key = node.key;
+        var val = node.value;
+        var getter = node.getter;
+        var setter = node.setter;
+
+        if (getter) {
+            print("get ");
+        } else if (setter) {
+            print("set ");
+        }
+
+        if (typeof key == "string") {
+            print(key);
+        } else {
+            key.accept(visitor, extra);
+        }
+
+        if (val) {
+            print(": ");
+            if (val instanceof FunctionExpression) {
+                printFunction(val, extra, comma? ',' : undefined);
+            } else {
+                val.accept(visitor, extra);
+                if (comma) print(',');
+            }
+        } else if (getter) {
+            printFunctionBody(getter, extra, comma? ',' : undefined);
+        } else if (setter) {
+            printFunctionBody(setter, extra, comma? ',' : undefined);
+        }
+    }
+
+
+    ast.accept(visitor = new (Java.extend(SimpleTreeVisitor)) {
+         visitAssignment: function(node, extra) {
+             node.variable.accept(visitor, extra);
+             print(" = ");
+             node.expression.accept(visitor, extra);
+         },
+
+         visitCompoundAssignment: function(node, extra) {
+             node.variable.accept(visitor, extra);
+             print(' ' + operatorOf(node.kind) + ' ');
+             node.expression.accept(visitor, extra);
+         },
+
+         visitBinary: function(node, extra) {
+             node.leftOperand.accept(visitor, extra);
+             print(' ' + operatorOf(node.kind) + ' ');
+             node.rightOperand.accept(visitor, extra);
+         },
+
+         visitBlock: function(node, extra) {
+             indent();
+             println('{');
+             printStatements(node.statements, extra);
+             indent();
+             println('}');
+         },
+
+         visitBreak: function(node, extra) {
+             indent();
+             print("break");
+             if (node.label) {
+                 print(' ' + node.label);
+             }
+             eol();
+         },
+
+         visitCase: function(node, extra) {
+             var expr = node.expression;
+             indent();
+             if (expr) {
+                 print("case ");
+                 expr.accept(visitor, extra);
+                 println(':');
+             } else {
+                 println("default:");
+             }
+
+             printStatements(node.statements, extra);
+         },
+
+         visitCatch: function(node, extra) {
+             indent();
+             print("catch (" + node.parameter.name);
+             var cond = node.condition;
+             if (cond) {
+                 print(" if ");
+                 cond.accept(visitor, extra);
+             }
+             print(')');
+             printStatement(node.block);
+         },
+
+         visitConditionalExpression: function(node, extra) {
+             print('(');
+             node.condition.accept(visitor, extra);
+             print(" ? ");
+             node.trueExpression.accept(visitor, extra);
+             print(" : ");
+             node.falseExpression.accept(visitor, extra);
+             print(')');
+         },
+
+         visitContinue: function(node, extra) {
+             indent();
+             print("continue");
+             if (node.label) {
+                 print(' ' + node.label);
+             }
+             eol();
+         },
+
+         visitDebugger: function(node, extra) {
+             indent();
+             print("debugger");
+             eol();
+         },
+
+         visitDoWhileLoop: function(node, extra) {
+             indent();
+             print("do");
+             printStatement(node.statement, extra);
+             indent();
+             print("while (");
+             node.condition.accept(visitor, extra);
+             print(')');
+             eol();
+         },
+
+         visitExpressionStatement: function(node, extra) {
+             indent();
+             var expr = node.expression;
+             var objLiteral = expr instanceof ObjectLiteral;
+             if (objLiteral) {
+                 print('(');
+             }
+
+             expr.accept(visitor, extra);
+             if (objLiteral) {
+                 print(')');
+             }
+             eol();
+         },
+
+         visitForLoop: function(node, extra) {
+             indent();
+             print("for (");
+             if (node.initializer) {
+                node.initializer.accept(visitor, extra);
+             }
+
+             print(';');
+             if (node.condition) {
+                node.condition.accept(visitor, extra);
+             }
+             print(';');
+             if (node.update) {
+                node.update.accept(visitor, extra);
+             }
+             print(')');
+             printStatement(node.statement);
+         },
+
+         visitForInLoop: function(node, extra) {
+             indent();
+             print("for ");
+             if (node.forEach) {
+                 print("each ");
+             }
+             print('(');
+             node.variable.accept(visitor, extra);
+             print(" in ");
+             node.expression.accept(visitor, extra);
+             print(')');
+             printStatement(node.statement);
+         },
+
+         visitFunctionCall: function(node, extra) {
+             var func = node.functionSelect;
+             // We need parens around function selected
+             // in many non-simple cases. Eg. function
+             // expression created and called immediately.
+             // Such parens are not preserved in AST and so
+             // introduce here.
+             var simpleFunc =
+                 (func instanceof ArrayAccess) ||
+                 (func instanceof Identifier) ||
+                 (func instanceof MemberSelect);
+             if (! simpleFunc) {
+                 print('(');
+             }
+             func.accept(visitor, extra);
+             if (! simpleFunc) {
+                 print(')');
+             }
+             print('(');
+             printCommaList(node.arguments, extra);
+             print(')');
+         },
+
+         visitFunctionDeclaration: function(node, extra) {
+             printFunction(node, extra);
+         },
+
+         visitFunctionExpression: function(node, extra) {
+             printFunction(node, extra);
+         },
+
+         visitIdentifier: function(node, extra) {
+             print(node.name);
+         },
+
+         visitIf: function(node, extra) {
+             indent();
+             print("if (");
+             node.condition.accept(visitor, extra);
+             print(')');
+             printStatement(node.thenStatement);
+             var el = node.elseStatement;
+             if (el) {
+                 indent();
+                 print("else");
+                 printStatement(el);
+             }
+         },
+
+         visitArrayAccess: function(node, extra) {
+             node.expression.accept(visitor, extra);
+             print('[');
+             node.index.accept(visitor, extra);
+             print(']');
+         },
+
+         visitArrayLiteral: function(node, extra) {
+             print('[');
+             printCommaList(node.elements);
+             print(']');
+         },
+
+         visitLabeledStatement: function(node, extra) {
+             indent();
+             print(node.label);
+             print(':');
+             printStatement(node.statement);
+         },
+
+         visitLiteral: function(node, extra) {
+             var val = node.value;
+             if (typeof val == "string") {
+                 print("'" + escapeString(val) + "'");
+             } else {
+                 print(val);
+             }
+         },
+
+         visitParenthesized: function(node, extra) {
+             print('(');
+             node.expression.accept(visitor, extra);
+             print(')');
+         },
+
+         visitReturn: function(node, extra) {
+             indent();
+             print("return");
+             if (node.expression) {
+                 print(' ');
+                 node.expression.accept(visitor, extra);
+             }
+             eol();
+         },
+
+         visitMemberSelect: function(node, extra) {
+             node.expression.accept(visitor, extra);
+             print('.' + node.identifier);
+         },
+
+         visitNew: function(node, extra) {
+             print("new ");
+             node.constructorExpression.accept(visitor, extra);
+         },
+
+         visitObjectLiteral: function(node, extra) {
+             println('{');
+             indentLevel++;
+             try {
+                 var props = node.properties;
+                 var len = props.length;
+                 for (var p = 0; p < len; p++) {
+                     var last = (p == len - 1);
+                     indent();
+                     printProperty(props[p], extra, !last);
+                     println();
+                 }
+             } finally {
+                 indentLevel--;
+             }
+             indent();
+             print('}');
+         },
+
+         visitRegExpLiteral: function(node, extra) {
+             print('/' + node.pattern + '/');
+             print(node.options);
+         },
+
+         visitEmptyStatement: function(node, extra) {
+             indent();
+             eol();
+         },
+
+         visitSwitch: function(node, extra) {
+             indent();
+             print("switch (");
+             node.expression.accept(visitor, extra);
+             println(") {");
+             indentLevel++;
+             try {
+                 for each (var c in node.cases) {
+                     c.accept(visitor, extra);
+                 }
+             } finally {
+                 indentLevel--;
+             }
+             indent();
+             println('}');
+         },
+
+         visitThrow: function(node, extra) {
+             indent();
+             print("throw ");
+             node.expression.accept(visitor, extra);
+             eol();
+         },
+
+         visitCompilationUnit: function(node, extra) {
+             for each (var stat in node.sourceElements) {
+                 stat.accept(visitor, extra);
+             }
+         },
+
+         visitTry: function(node, extra) {
+             indent();
+             print("try");
+             printStatement(node.block);
+             var catches = node.catches;
+             for each (var c in catches) {
+                 c.accept(visitor, extra);
+             }
+             var finallyBlock = node.finallyBlock;
+             if (finallyBlock) {
+                 indent();
+                 print("finally");
+                 printStatement(finallyBlock);
+             }
+         },
+
+         visitInstanceOf: function(node, extra) {
+             node.expression.accept(visitor, extra);
+             print(" instanceof ");
+             node.type.accept(visitor, extra);
+         },
+
+         visitUnary: function(node, extra) {
+             var kind = node.kind;
+             var prefix = kind != Kind.POSTFIX_INCREMENT && kind != Kind.POSTFIX_DECREMENT;
+             if (prefix) {
+                 print(operatorOf(kind));
+             }
+             node.expression.accept(visitor, extra);
+             if (!prefix) {
+                 print(operatorOf(kind));
+             }
+         },
+
+         visitVariable: function(node, extra) {
+             indent();
+             print("var " + node.name);
+             var init = node.initializer;
+             if (init) {
+                 print(" = ");
+                 if (init instanceof FunctionExpression) {
+                     printFunction(init, extra, "");
+                 } else {
+                     init.accept(visitor, extra);
+                 }
+             }
+             eol();
+         },
+
+         visitWhileLoop: function(node, extra) {
+             indent();
+             print("while (");
+             node.condition.accept(visitor, extra);
+             print(')');
+             printStatement(node.statement);
+         },
+
+         visitWith: function(node, extra) {
+             indent();
+             print("with (");
+             node.scope.accept(visitor, extra);
+             print(')');
+             printStatement(node.statement);
+         }
+    }, null);
+}
+
+prettyPrint(file);