/*
* Copyright 2008 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.jjs.impl;
import com.google.gwt.core.ext.UnableToCompleteException;
import com.google.gwt.dev.jjs.SourceInfo;
import com.google.gwt.dev.jjs.ast.Context;
import com.google.gwt.dev.jjs.ast.JBinaryOperation;
import com.google.gwt.dev.jjs.ast.JBinaryOperator;
import com.google.gwt.dev.jjs.ast.JDeclaredType;
import com.google.gwt.dev.jjs.ast.JExpression;
import com.google.gwt.dev.jjs.ast.JExpressionStatement;
import com.google.gwt.dev.jjs.ast.JField;
import com.google.gwt.dev.jjs.ast.JFieldRef;
import com.google.gwt.dev.jjs.ast.JLocal;
import com.google.gwt.dev.jjs.ast.JLocalRef;
import com.google.gwt.dev.jjs.ast.JMethod;
import com.google.gwt.dev.jjs.ast.JMethodBody;
import com.google.gwt.dev.jjs.ast.JMethodCall;
import com.google.gwt.dev.jjs.ast.JProgram;
import com.google.gwt.dev.jjs.ast.JReturnStatement;
import com.google.gwt.dev.jjs.ast.JStatement;
import com.google.gwt.dev.jjs.ast.js.JMultiExpression;
import com.google.gwt.dev.util.Preconditions;
import com.google.gwt.dev.util.Strings;
import java.util.regex.Pattern;
/**
* Test case for testing Jjs optimizers. Adds a convenient Result class.
*/
public abstract class OptimizerTestBase extends JJSTestBase {
protected boolean runDeadCodeElimination = false;
protected final class Result {
private final String returnType;
private final String originalCode;
private final boolean madeChanges;
private final JProgram optimizedProgram;
private final String methodName;
public Result(JProgram optimizedProgram, String returnType,
String methodName, String originalCode, boolean madeChanges) {
this.optimizedProgram = optimizedProgram;
this.returnType = returnType;
this.methodName = methodName;
this.originalCode = originalCode;
this.madeChanges = madeChanges;
}
public void into(String... expected) throws UnableToCompleteException {
// We can't compile expected code into non-main method.
Preconditions.checkState(methodName.equals(MAIN_METHOD_NAME));
JProgram program = compileSnippet(returnType,
Strings.join(expected, "\n"));
String expectedSource =
OptimizerTestBase.findMethod(program, methodName).getBody().toSource();
String actualSource =
OptimizerTestBase.findMethod(optimizedProgram, methodName).
getBody().toSource();
assertEquals(originalCode, expectedSource, actualSource);
}
public void intoString(String... expected) {
String expectedSource = Strings.join(expected, "\n");
String actualSource =
OptimizerTestBase.findMethod(optimizedProgram, methodName).
getBody().toSource();
// Trim surrounding {} and unindent body once
assertTrue(actualSource.startsWith("{"));
assertTrue(actualSource.endsWith("}"));
actualSource = actualSource.substring(1, actualSource.length() - 2).trim();
actualSource = Pattern.compile("^ ", Pattern.MULTILINE).
matcher(actualSource).replaceAll("");
assertEquals(originalCode, expectedSource, actualSource);
}
public void noChange() {
assertFalse(madeChanges);
}
public JMethod findMethod(String methodName) {
return OptimizerTestBase.findMethod(optimizedProgram, methodName);
}
public JField findField(String fieldName) {
return OptimizerTestBase.findField(optimizedProgram,
"EntryPoint." + fieldName);
}
public JDeclaredType findClass(String className) {
return OptimizerTestBase.findType(optimizedProgram, className);
}
}
/**
* Makes implicit <code>$clinit()</code> calls explicit to mimic the effect of other
* optimizations. Otherwise can not test optimizations that involve <code>$clinit</code> calls
* as they don't appear when compiling small snippets.
*
* @param method method to transform to make <code>$clinit</code> calls explicit.
*/
private void insertImplicitClinitCalls(final JMethod method) {
// Mimic the method inliner which inserts clinits calls prior to method or field dereference.
// The actual clinit() calls might be inserted as a result of optimizations: e,g,
// DeadCodeElimination inserts clinit calls when it removes (some) field accesses or method
// calls.
final JMethodBody body = (JMethodBody) method.getBody();
new TempLocalVisitor() {
private JMethodCall createClinitCall(SourceInfo sourceInfo, JDeclaredType targetType) {
JMethod clinit = targetType.getClinitTarget().getClinitMethod();
assert (JProgram.isClinit(clinit));
return new JMethodCall(sourceInfo, null, clinit);
}
private JMultiExpression createMultiExpressionForInstanceAndClinit(JExpression x) {
JMultiExpression multi = new JMultiExpression(x.getSourceInfo());
JMethodCall clinit = null;
if (x instanceof JMethodCall) {
JExpression instance = ((JMethodCall) x).getInstance();
// Any instance expression goes first (this can happen even with statics).
if (instance != null) {
multi.exprs.add(instance);
JLocal var = createTempLocal(instance.getSourceInfo(), instance.getType());
JLocalRef localRef = new JLocalRef(var.getSourceInfo(), var);
instance = new JBinaryOperation(instance.getSourceInfo(), localRef.getType(),
JBinaryOperator.ASG, localRef, instance);
}
clinit = createClinitCall(x.getSourceInfo(),
((JMethodCall) x).getTarget().getEnclosingType());
} else if (x instanceof JFieldRef) {
clinit = createClinitCall(x.getSourceInfo(), ((JFieldRef) x).getEnclosingType());
}
// If we need a clinit call, add it first
if (clinit != null) {
multi.exprs.add(clinit);
}
multi.exprs.add(x);
return multi;
}
@Override
public void endVisit(JMethodCall x, Context ctx) {
ctx.replaceMe(createMultiExpressionForInstanceAndClinit(x));
}
@Override
public void endVisit(JFieldRef x, Context ctx) {
ctx.replaceMe(createMultiExpressionForInstanceAndClinit(x));
}
}.accept(method);
}
protected final Result optimize(final String returnType,
final String... codeSnippet) throws UnableToCompleteException {
return optimizeMethod(MAIN_METHOD_NAME, returnType, codeSnippet);
}
/**
* Test the effect of an optimization on a JMultiExpression.
* JMultiExpression can not be constructed from source code at the moment as it is not a valid
* java source construct.
*
* @param addClinitCalls whether to insert the implicit clinit calls. This is necessary because
* clinit() methods are synthetic can not be inserted explicitly as source
* code calls.
* @param returnType the return type of the JMultiExpression. Must be <code>void</code> or
* compatible with the last expression.
* @param expressionSnippets source code of the expressions.
* @return the optimization result.
* @throws UnableToCompleteException
*/
protected final Result optimizeExpressions(boolean addClinitCalls, final String returnType,
final String... expressionSnippets)
throws UnableToCompleteException {
// TODO(rluble): Not very elegant to require that the snippets be statements instead of
// expressions.
assert expressionSnippets.length > 0;
// Compile as statements
if (!returnType.equals("void")) {
expressionSnippets[expressionSnippets.length - 1] =
"return " + expressionSnippets[expressionSnippets.length - 1];
}
String snippet = Strings.join(expressionSnippets, ";\n") + ";\n";
final JProgram program = compileSnippet(returnType, snippet);
JMethod method = findMethod(program, MAIN_METHOD_NAME);
JMethodBody body = (JMethodBody) method.getBody();
JMultiExpression multi = new JMultiExpression(body.getSourceInfo());
// Transform statement sequence into a JMultiExpression
for (JStatement stmt : body.getStatements()) {
if (stmt instanceof JExpressionStatement) {
JExpressionStatement exprStmt = (JExpressionStatement) stmt;
JExpression expr = exprStmt.getExpr();
multi.exprs.add(expr);
} else if (stmt instanceof JReturnStatement) {
JReturnStatement returnStatement = (JReturnStatement) stmt;
JExpression expr = returnStatement.getExpr();
if (expr != null) {
multi.exprs.add(expr);
}
} else {
assert false : "Not a valid multiexpression";
}
}
// Take care of the return type
JStatement multiStm;
if (!returnType.equals("void")) {
multiStm = new JReturnStatement(multi.getSourceInfo(), multi);
} else {
multiStm = multi.makeStatement();
}
// Replace the method body
JMethodBody newBody = new JMethodBody(method.getBody().getSourceInfo());
newBody.getBlock().addStmt(multiStm);
method.setBody(newBody);
newBody.setMethod(method);
if (addClinitCalls) {
insertImplicitClinitCalls(method);
}
// Finally optimize.
boolean madeChanges = optimizeMethod(program, method);
if (madeChanges && runDeadCodeElimination) {
DeadCodeElimination.exec(program);
}
return new Result(program, returnType, MAIN_METHOD_NAME, snippet, madeChanges);
}
protected final Result optimizeMethod(final String methodName,
final String mainMethodReturnType, final String... mainMethodSnippet)
throws UnableToCompleteException {
String snippet = Strings.join(mainMethodSnippet, "\n");
JProgram program = compileSnippet(mainMethodReturnType, snippet);
JMethod method = findMethod(program, methodName);
boolean madeChanges = optimizeMethod(program, method);
if (madeChanges && runDeadCodeElimination) {
DeadCodeElimination.exec(program);
}
return new Result(program, mainMethodReturnType, methodName, snippet, madeChanges);
}
protected abstract boolean optimizeMethod(JProgram program, JMethod method);
}