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/*
* Copyright © 2009 Reinier Zwitserloot and Roel Spilker.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package lombok.eclipse.agent;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import org.objectweb.asm.ClassAdapter;
import org.objectweb.asm.ClassReader;
import org.objectweb.asm.ClassVisitor;
import org.objectweb.asm.ClassWriter;
import org.objectweb.asm.Label;
import org.objectweb.asm.MethodAdapter;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;
/**
* Transforms Eclipse's <code>org.eclipse.jdt.internal.compiler.parser.Parser</code> class,
* which handles all the actual java source to AST tree conversion in eclipse.
*
* Transformations applied:<ul>
* <li>The <code>CompilationUnitDeclaration endParse(int)</code> method is instrumented to call
* the lombok framework via ClassLoaderWorkaround to TransformEclipseAST with the CompilationUnitDeclaration
* right before it returns the CompilationUnitDeclaration.</li>
* <li>The <code>getMethodBodies(CompilationUnitDeclaration)</code> is similarly instrumented; eclipse uses a
* 2-step parsing system, where the bodies of methods aren't filled in until its actually neccessary. Lombok
* gets a chance to change the AST immediately after either step.</li>
* <li>The <code>parse(MethodDeclaration, CUD)</code>, <code>parse(ConstructorDeclaration, CUD)</code> and
* <code>parse(Initializer, TypeDeclaration, CUD)</code> methods are all instrumented to not attempt to
* complete parsing a method generated by lombok, as the source positions are obviously all wrong
* (the method content isn't in the source file!) - lombok has already filled in the complete AST.
*
* Bit24 on the flags field on all ASTNode objects is used as a marker.</li>
*/
class EclipseParserTransformer {
private static final String COMPILER_PKG =
"Lorg/eclipse/jdt/internal/compiler/ast/";
private static final String TARGET_STATIC_CLASS = "java/lombok/eclipse/ClassLoaderWorkaround";
private static final String TARGET_STATIC_METHOD_NAME = "transformCompilationUnitDeclaration";
private static final String TARGET_STATIC_METHOD_DESC = "(Ljava/lang/Object;Ljava/lang/Object;)V";
private static final Map<String, Class<? extends MethodVisitor>> rewriters;
static {
Map<String, Class<? extends MethodVisitor>> map = new HashMap<String, Class<? extends MethodVisitor>>();
map.put(String.format("endParse(I)%sCompilationUnitDeclaration;", COMPILER_PKG), EndParsePatcher.class);
map.put(String.format("getMethodBodies(%sCompilationUnitDeclaration;)V", COMPILER_PKG), GetMethodBodiesPatcher.class);
map.put(String.format("parse(%1$sMethodDeclaration;%1$sCompilationUnitDeclaration;)V", COMPILER_PKG), ParseBlockContainerPatcher.class);
map.put(String.format("parse(%1$sConstructorDeclaration;%1$sCompilationUnitDeclaration;Z)V", COMPILER_PKG), ParseBlockContainerPatcher.class);
map.put(String.format("parse(%1$sInitializer;%1$sTypeDeclaration;%1$sCompilationUnitDeclaration;)V", COMPILER_PKG), ParseBlockContainerPatcher.class);
rewriters = Collections.unmodifiableMap(map);
}
byte[] transform(byte[] classfileBuffer) {
ClassReader reader = new ClassReader(classfileBuffer);
ClassWriter writer = new ClassWriter(reader, 0);
ClassAdapter adapter = new ParserPatcherAdapter(writer);
reader.accept(adapter, 0);
return writer.toByteArray();
}
static RuntimeException sneakyThrow(Throwable t) {
if ( t == null ) throw new NullPointerException("t");
EclipseParserTransformer.<RuntimeException>sneakyThrow0(t);
return null;
}
@SuppressWarnings("unchecked")
private static <T extends Throwable> void sneakyThrow0(Throwable t) throws T {
throw (T)t;
}
private static class ParserPatcherAdapter extends ClassAdapter {
public ParserPatcherAdapter(ClassVisitor cv) {
super(cv);
}
@Override public MethodVisitor visitMethod(int access, String name, String desc,
String signature, String[] exceptions) {
MethodVisitor writerVisitor = super.visitMethod(access, name, desc, signature, exceptions);
Class<? extends MethodVisitor> targetVisitorClass = rewriters.get(name+desc);
if ( targetVisitorClass == null ) return writerVisitor;
try {
Constructor<? extends MethodVisitor> c = targetVisitorClass.getDeclaredConstructor(MethodVisitor.class);
c.setAccessible(true);
return c.newInstance(writerVisitor);
} catch ( InvocationTargetException e ) {
throw sneakyThrow(e.getCause());
} catch ( Exception e ) {
//NoSuchMethodException: We know they exist.
//IllegalAccessException: We called setAccessible.
//InstantiationException: None of these classes are abstract.
throw sneakyThrow(e);
}
}
}
private static final int BIT24 = 0x800000;
static class GetMethodBodiesPatcher extends MethodAdapter {
GetMethodBodiesPatcher(MethodVisitor mv) {
super(mv);
}
@Override public void visitInsn(int opcode) {
if ( opcode == Opcodes.RETURN ) {
//injects: ClassLoaderWorkaround.transformCUD(parser, compilationUnitDeclaration);
super.visitVarInsn(Opcodes.ALOAD, 0);
super.visitVarInsn(Opcodes.ALOAD, 1);
super.visitMethodInsn(Opcodes.INVOKESTATIC, TARGET_STATIC_CLASS,
TARGET_STATIC_METHOD_NAME, TARGET_STATIC_METHOD_DESC);
}
super.visitInsn(opcode);
}
}
static class ParseBlockContainerPatcher extends MethodAdapter {
ParseBlockContainerPatcher(MethodVisitor mv) {
super(mv);
}
@Override public void visitCode() {
//injects: if ( constructorDeclaration.bits & BIT24 > 0 ) return;
mv.visitVarInsn(Opcodes.ALOAD, 1);
mv.visitFieldInsn(Opcodes.GETFIELD, "org/eclipse/jdt/internal/compiler/ast/ASTNode", "bits", "I");
mv.visitLdcInsn(Integer.valueOf(BIT24));
mv.visitInsn(Opcodes.IAND);
Label l0 = new Label();
mv.visitJumpInsn(Opcodes.IFLE, l0);
mv.visitInsn(Opcodes.RETURN);
mv.visitLabel(l0);
mv.visitFrame(Opcodes.F_SAME, 0, null, 0, null);
super.visitCode();
}
}
static class EndParsePatcher extends MethodAdapter {
private static final String TARGET_STATIC_METHOD_NAME = "transformCompilationUnitDeclaration";
EndParsePatcher(MethodVisitor mv) {
super(mv);
}
@Override public void visitInsn(int opcode) {
if ( opcode == Opcodes.ARETURN ) {
//injects: ClassLoaderWorkaround.transformCUD(parser, compilationUnitDeclaration);
super.visitInsn(Opcodes.DUP);
super.visitVarInsn(Opcodes.ALOAD, 0);
super.visitInsn(Opcodes.SWAP);
super.visitMethodInsn(Opcodes.INVOKESTATIC, TARGET_STATIC_CLASS,
TARGET_STATIC_METHOD_NAME, TARGET_STATIC_METHOD_DESC);
}
super.visitInsn(opcode);
}
}
}
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