dev/core/test/com/google/gwt/dev/js/JsDuplicateFunctionRemoverTest.java - gwt - Git at Google

 /*
  * Copyright 2009 Google Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License"); you may not
  * use this file except in compliance with the License. You may obtain a copy of
  * the License at
  *
  * http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
  * License for the specific language governing permissions and limitations under
  * the License.
  */
 package com.google.gwt.dev.js;

 import com.google.gwt.dev.jjs.SourceOrigin;
 import com.google.gwt.dev.js.ast.JsBinaryOperation;
 import com.google.gwt.dev.js.ast.JsBinaryOperator;
 import com.google.gwt.dev.js.ast.JsContext;
 import com.google.gwt.dev.js.ast.JsFunction;
 import com.google.gwt.dev.js.ast.JsModVisitor;
 import com.google.gwt.dev.js.ast.JsName;
 import com.google.gwt.dev.js.ast.JsNameRef;
 import com.google.gwt.dev.js.ast.JsProgram;
 import com.google.gwt.dev.js.ast.JsScope;
 import com.google.gwt.dev.js.ast.JsStatement;
 import com.google.gwt.dev.js.ast.JsVisitor;
 import com.google.gwt.dev.util.DefaultTextOutput;
 import com.google.gwt.dev.util.TextOutput;

 import java.io.StringReader;
 import java.lang.reflect.Method;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;


 /**
  * Tests {@link JsDuplicateFunctionRemover}.
  */
 public class JsDuplicateFunctionRemoverTest extends OptimizerTestBase {

   private static class MockNameGenerator implements FreshNameGenerator {
     private int counter = 0;

     @Override
     public String getFreshName() {
       return "__DUP" + counter++;
     }
   }

   // JsDuplicateFunctionRemover does not have a one parameter exec function. Test infrastructure
   // call exec(JsProgram) reflectively.
   private static class JsDuplicateFunctionRemoverProxy {
     static public void exec(JsProgram program) {
       JsDuplicateFunctionRemover.exec(program, new MockNameGenerator());
     }
   }

   public void testDontRemoveCtors() throws Exception {
     // As fieldref qualifier
     assertEquals("function a(){}\n;function b(){}\nb.prototype={};a();b();",
         optimize("function a(){};function b(){} b.prototype={}; a(); b();"));
     // As parameter
     assertEquals(
         "function defineClass(a,b){}\n;function a(){}\n;function b(){}\ndefineClass(a,b);a();b();",
         optimize("function defineClass(a,b){};function a(){};function b(){}"
             + " defineClass(a,b); a(); b();"));
   }

   public void testRemoveDuplicates() throws Exception {
     assertEquals("function a(){}\n;a();a();",
         optimize("function a(){};function b(){} a(); b();"));
   }

   public void testVirtualRemoveDuplicates() throws Exception {
     JsProgram program = new JsProgram();
     String js = "_.method1=function(){};_.method2=function(){};_.method1();_.method2();";
     List<JsStatement> input = JsParser.parse(SourceOrigin.UNKNOWN,
       program.getScope(), new StringReader(js));
     program.getGlobalBlock().getStatements().addAll(input);

     // Mark all functions as if they were translated from Java sources.
     setAllFromJava(program);

     String firstName = new MockNameGenerator().getFreshName();
     assertEquals("_.method1=" + firstName + ";_.method2=" + firstName +
         ";_.method1();_.method2();function " + firstName + "(){}\n",
         optimize(program, JsSymbolResolver.class, JsDuplicateFunctionRemoverProxy.class));
   }


   /**
    * Test for one of the bugs causing issue 8284. JsObfuscateNamer was reassigning the same names
    * across different fragments.
    */
   public void testDuplicateNamesWithCodeSplitterError() throws Exception {
     JsProgram program = new JsProgram();
     // Reference to a in .b is to the top level scope a function where the one in _.c is to the
     // local a definition.
     //
     // After deduping _.b and _.c the identifier a in the deduped function points to the top level
     // scope a function and runing a namer afterwards makes the deduping invalid.
     String fragment0js = "_.a=function (){return _.a;}; _.b=function (){return _.a}; _.a();_.b();";
     String fragment1js = "_.c=function (){return _.c;}; _.d=function (){return _.c}; _.c();_.d();";

     List<JsStatement> fragment0 = JsParser.parse(SourceOrigin.UNKNOWN,
         program.getScope(), new StringReader(fragment0js));
     List<JsStatement> fragment1 = JsParser.parse(SourceOrigin.UNKNOWN,
         program.getScope(), new StringReader(fragment1js));
     program.setFragmentCount(2);
     program.getFragmentBlock(0).getStatements().addAll(fragment0);
     program.getFragmentBlock(1).getStatements().addAll(fragment1);

     // Mark all functions as if they were translated from Java sources.
     setAllFromJava(program);

     optimize(program, JsSymbolResolver.class, JsDuplicateFunctionRemoverProxy.class);

     // There should be two distinct dedupped functions here.
     MockNameGenerator tempFreshNameGenerator = new MockNameGenerator();
     String firstName = tempFreshNameGenerator.getFreshName();
     String secondName = tempFreshNameGenerator.getFreshName();

     assertNotNull(program.getScope().findExistingName(secondName));
   }

   private static class AssignmentGatherer extends JsModVisitor {

     final Map<String, JsName> assignments = new HashMap<String, JsName>();

     @Override
     public void endVisit(JsBinaryOperation expr, JsContext ctx) {
       if (expr.getOperator() != JsBinaryOperator.ASG || !(expr.getArg1() instanceof JsNameRef) ||
           !(expr.getArg2() instanceof JsNameRef)) {
         return;
       }
       assignments.put(expr.getArg1().toString(), ((JsNameRef) expr.getArg2()).getName());
     }

     public static Map<String, JsName> exec(JsProgram jsProgram) {
       AssignmentGatherer assignmentGatherer = new AssignmentGatherer();
       assignmentGatherer.accept(jsProgram);
       return assignmentGatherer.assignments;
     }
   }

   /**
    * Test for one of the bugs causing issue 8284. JsObfuscateNamer was used to assign
    * obfuscated names to deduped functions and as a result it might have modified the other names
    * that had been assigned invalidating the irrevocable decision made by the deduper.
    */
   public void testRerunNamerError() throws Exception {
     JsProgram program = new JsProgram();
     // Reference to a in _.b is to the top level scope a function where the one in _.c is to the
     // local a definition.
     //
     // After deduping _.b and _.c the identifier a in the deduped function points to the top level
     // scope a function and runing a namer afterwards makes the deduping invalid.

     // CAVEAT: The two functions that have {return a;} as their bodies are not actually duplicates
     // but we use them to model functions that refer to names at different scopes. Because this
     // optimization only runs on JsFunctions that come from Java source this situation does not
     // happen.
     String js = "var c; function a(){return f1;}; function f1() {_.b = function() {return a;} }; "
         + "function f2() { var a = null; _.c = function() {return a;} };f1();f2();_.b();_.c();";
     List<JsStatement> input = JsParser.parse(SourceOrigin.UNKNOWN,
         program.getScope(), new StringReader(js));
     program.getGlobalBlock().getStatements().addAll(input);

     // Mark all functions as if they were translated from Java sources.
     setAllFromJava(program);

     // Get the JsNames for the top level a and the f2() scoped a.
     JsName topScope_a = program.getScope().findExistingName("a");
     JsName f2_a = null;
     for (JsScope scope : program.getScope().getChildren()) {
       if (scope.toString().startsWith("function f2->")) {
         f2_a = scope.findExistingName("a");
       }
     }

     assertTrue(topScope_a != f2_a);

     optimize(program, JsSymbolResolver.class, JsDuplicateFunctionRemoverProxy.class);

     // collect values assigned to some identifiers.
     final Map<String, JsName> assignments = AssignmentGatherer.exec(program);

     // If the function have been dedupped then there is a constraint that the different JsNames
     // they referred to are obfuscated to the same id.
     // Hence if _.c and _.b are collapsed the top scope name "a" and the one in f2() need to remain
     // the same.
     assertTrue(assignments.get("_.b") != assignments.get("_.c") ||
         topScope_a.getShortIdent().equals(f2_a.getShortIdent()));
   }

   private static void setAllFromJava(JsProgram program) {
     new JsModVisitor() {
       @Override
       public void endVisit(JsFunction func, JsContext ctx) {
         func.setFromJava(true);
       }
     }.accept(program);
   }

   private String optimize(String js) throws Exception {
     return optimizeToSource(js, JsSymbolResolver.class,
         JsDuplicateFunctionRemoverProxy.class);
   }

   /**
    * Optimize a JS program.
    *
    * @param program the source program
    * @param toExec a list of classes that implement
    *          <code>static void exec(JsProgram)</code>
    * @return optimized JS
    */
   protected String optimize(JsProgram program, Class<?>... toExec) throws Exception {

     for (Class<?> clazz : toExec) {
       Method m = clazz.getMethod("exec", JsProgram.class);
       m.invoke(null, program);
     }

     TextOutput text = new DefaultTextOutput(true);
     JsVisitor generator = new JsSourceGenerationVisitor(text);

     generator.accept(program);
     return text.toString();
   }
 }
	/*
	* Copyright 2009 Google Inc.
	*
	* Licensed under the Apache License, Version 2.0 (the "License"); you may not
	* use this file except in compliance with the License. You may obtain a copy of
	* the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
	* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
	* License for the specific language governing permissions and limitations under
	* the License.
	*/
	package com.google.gwt.dev.js;

	import com.google.gwt.dev.jjs.SourceOrigin;
	import com.google.gwt.dev.js.ast.JsBinaryOperation;
	import com.google.gwt.dev.js.ast.JsBinaryOperator;
	import com.google.gwt.dev.js.ast.JsContext;
	import com.google.gwt.dev.js.ast.JsFunction;
	import com.google.gwt.dev.js.ast.JsModVisitor;
	import com.google.gwt.dev.js.ast.JsName;
	import com.google.gwt.dev.js.ast.JsNameRef;
	import com.google.gwt.dev.js.ast.JsProgram;
	import com.google.gwt.dev.js.ast.JsScope;
	import com.google.gwt.dev.js.ast.JsStatement;
	import com.google.gwt.dev.js.ast.JsVisitor;
	import com.google.gwt.dev.util.DefaultTextOutput;
	import com.google.gwt.dev.util.TextOutput;

	import java.io.StringReader;
	import java.lang.reflect.Method;
	import java.util.HashMap;
	import java.util.List;
	import java.util.Map;


	/**
	* Tests {@link JsDuplicateFunctionRemover}.
	*/
	public class JsDuplicateFunctionRemoverTest extends OptimizerTestBase {

	private static class MockNameGenerator implements FreshNameGenerator {
	private int counter = 0;

	@Override
	public String getFreshName() {
	return "__DUP" + counter++;
	}
	}

	// JsDuplicateFunctionRemover does not have a one parameter exec function. Test infrastructure
	// call exec(JsProgram) reflectively.
	private static class JsDuplicateFunctionRemoverProxy {
	static public void exec(JsProgram program) {
	JsDuplicateFunctionRemover.exec(program, new MockNameGenerator());
	}
	}

	public void testDontRemoveCtors() throws Exception {
	// As fieldref qualifier
	assertEquals("function a(){}\n;function b(){}\nb.prototype={};a();b();",
	optimize("function a(){};function b(){} b.prototype={}; a(); b();"));
	// As parameter
	assertEquals(
	"function defineClass(a,b){}\n;function a(){}\n;function b(){}\ndefineClass(a,b);a();b();",
	optimize("function defineClass(a,b){};function a(){};function b(){}"
	+ " defineClass(a,b); a(); b();"));
	}

	public void testRemoveDuplicates() throws Exception {
	assertEquals("function a(){}\n;a();a();",
	optimize("function a(){};function b(){} a(); b();"));
	}

	public void testVirtualRemoveDuplicates() throws Exception {
	JsProgram program = new JsProgram();
	String js = "_.method1=function(){};_.method2=function(){};_.method1();_.method2();";
	List<JsStatement> input = JsParser.parse(SourceOrigin.UNKNOWN,
	program.getScope(), new StringReader(js));
	program.getGlobalBlock().getStatements().addAll(input);

	// Mark all functions as if they were translated from Java sources.
	setAllFromJava(program);

	String firstName = new MockNameGenerator().getFreshName();
	assertEquals("_.method1=" + firstName + ";_.method2=" + firstName +
	";_.method1();_.method2();function " + firstName + "(){}\n",
	optimize(program, JsSymbolResolver.class, JsDuplicateFunctionRemoverProxy.class));
	}


	/**
	* Test for one of the bugs causing issue 8284. JsObfuscateNamer was reassigning the same names
	* across different fragments.
	*/
	public void testDuplicateNamesWithCodeSplitterError() throws Exception {
	JsProgram program = new JsProgram();
	// Reference to a in .b is to the top level scope a function where the one in _.c is to the
	// local a definition.
	//
	// After deduping _.b and _.c the identifier a in the deduped function points to the top level
	// scope a function and runing a namer afterwards makes the deduping invalid.
	String fragment0js = "_.a=function (){return _.a;}; _.b=function (){return _.a}; _.a();_.b();";
	String fragment1js = "_.c=function (){return _.c;}; _.d=function (){return _.c}; _.c();_.d();";

	List<JsStatement> fragment0 = JsParser.parse(SourceOrigin.UNKNOWN,
	program.getScope(), new StringReader(fragment0js));
	List<JsStatement> fragment1 = JsParser.parse(SourceOrigin.UNKNOWN,
	program.getScope(), new StringReader(fragment1js));
	program.setFragmentCount(2);
	program.getFragmentBlock(0).getStatements().addAll(fragment0);
	program.getFragmentBlock(1).getStatements().addAll(fragment1);

	// Mark all functions as if they were translated from Java sources.
	setAllFromJava(program);

	optimize(program, JsSymbolResolver.class, JsDuplicateFunctionRemoverProxy.class);

	// There should be two distinct dedupped functions here.
	MockNameGenerator tempFreshNameGenerator = new MockNameGenerator();
	String firstName = tempFreshNameGenerator.getFreshName();
	String secondName = tempFreshNameGenerator.getFreshName();

	assertNotNull(program.getScope().findExistingName(secondName));
	}

	private static class AssignmentGatherer extends JsModVisitor {

	final Map<String, JsName> assignments = new HashMap<String, JsName>();

	@Override
	public void endVisit(JsBinaryOperation expr, JsContext ctx) {
	if (expr.getOperator() != JsBinaryOperator.ASG \|\| !(expr.getArg1() instanceof JsNameRef) \|\|
	!(expr.getArg2() instanceof JsNameRef)) {
	return;
	}
	assignments.put(expr.getArg1().toString(), ((JsNameRef) expr.getArg2()).getName());
	}

	public static Map<String, JsName> exec(JsProgram jsProgram) {
	AssignmentGatherer assignmentGatherer = new AssignmentGatherer();
	assignmentGatherer.accept(jsProgram);
	return assignmentGatherer.assignments;
	}
	}

	/**
	* Test for one of the bugs causing issue 8284. JsObfuscateNamer was used to assign
	* obfuscated names to deduped functions and as a result it might have modified the other names
	* that had been assigned invalidating the irrevocable decision made by the deduper.
	*/
	public void testRerunNamerError() throws Exception {
	JsProgram program = new JsProgram();
	// Reference to a in _.b is to the top level scope a function where the one in _.c is to the
	// local a definition.
	//
	// After deduping _.b and _.c the identifier a in the deduped function points to the top level
	// scope a function and runing a namer afterwards makes the deduping invalid.

	// CAVEAT: The two functions that have {return a;} as their bodies are not actually duplicates
	// but we use them to model functions that refer to names at different scopes. Because this
	// optimization only runs on JsFunctions that come from Java source this situation does not
	// happen.
	String js = "var c; function a(){return f1;}; function f1() {_.b = function() {return a;} }; "
	+ "function f2() { var a = null; _.c = function() {return a;} };f1();f2();_.b();_.c();";
	List<JsStatement> input = JsParser.parse(SourceOrigin.UNKNOWN,
	program.getScope(), new StringReader(js));
	program.getGlobalBlock().getStatements().addAll(input);

	// Mark all functions as if they were translated from Java sources.
	setAllFromJava(program);

	// Get the JsNames for the top level a and the f2() scoped a.
	JsName topScope_a = program.getScope().findExistingName("a");
	JsName f2_a = null;
	for (JsScope scope : program.getScope().getChildren()) {
	if (scope.toString().startsWith("function f2->")) {
	f2_a = scope.findExistingName("a");
	}
	}

	assertTrue(topScope_a != f2_a);

	optimize(program, JsSymbolResolver.class, JsDuplicateFunctionRemoverProxy.class);

	// collect values assigned to some identifiers.
	final Map<String, JsName> assignments = AssignmentGatherer.exec(program);

	// If the function have been dedupped then there is a constraint that the different JsNames
	// they referred to are obfuscated to the same id.
	// Hence if _.c and _.b are collapsed the top scope name "a" and the one in f2() need to remain
	// the same.
	assertTrue(assignments.get("_.b") != assignments.get("_.c") \|\|
	topScope_a.getShortIdent().equals(f2_a.getShortIdent()));
	}

	private static void setAllFromJava(JsProgram program) {
	new JsModVisitor() {
	@Override
	public void endVisit(JsFunction func, JsContext ctx) {
	func.setFromJava(true);
	}
	}.accept(program);
	}

	private String optimize(String js) throws Exception {
	return optimizeToSource(js, JsSymbolResolver.class,
	JsDuplicateFunctionRemoverProxy.class);
	}

	/**
	* Optimize a JS program.
	*
	* @param program the source program
	* @param toExec a list of classes that implement
	* <code>static void exec(JsProgram)</code>
	* @return optimized JS
	*/
	protected String optimize(JsProgram program, Class<?>... toExec) throws Exception {

	for (Class<?> clazz : toExec) {
	Method m = clazz.getMethod("exec", JsProgram.class);
	m.invoke(null, program);
	}

	TextOutput text = new DefaultTextOutput(true);
	JsVisitor generator = new JsSourceGenerationVisitor(text);

	generator.accept(program);
	return text.toString();
	}
	}