/*
* 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();
}
}