Examples with CodeIterator javassist.bytecode.CodeIterator used on opensource projects

Example 1 with CodeIterator

use of javassist.bytecode.CodeIterator in project hibernate-orm by hibernate.

the class PersistentAttributesEnhancer method enhanceAttributesAccess.

protected void enhanceAttributesAccess(CtClass managedCtClass, IdentityHashMap<String, PersistentAttributeAccessMethods> attributeDescriptorMap) {
    final ConstPool constPool = managedCtClass.getClassFile().getConstPool();
    final ClassPool classPool = managedCtClass.getClassPool();
    for (Object oMethod : managedCtClass.getClassFile().getMethods()) {
        final MethodInfo methodInfo = (MethodInfo) oMethod;
        final String methodName = methodInfo.getName();
        // skip methods added by enhancement and abstract methods (methods without any code)
        if (methodName.startsWith("$$_hibernate_") || methodInfo.getCodeAttribute() == null) {
            continue;
        }
        try {
            final CodeIterator itr = methodInfo.getCodeAttribute().iterator();
            while (itr.hasNext()) {
                final int index = itr.next();
                final int op = itr.byteAt(index);
                if (op != Opcode.PUTFIELD && op != Opcode.GETFIELD) {
                    continue;
                }
                // only transform access to fields of the entity being enhanced
                if (!managedCtClass.getName().equals(constPool.getFieldrefClassName(itr.u16bitAt(index + 1)))) {
                    continue;
                }
                final String fieldName = constPool.getFieldrefName(itr.u16bitAt(index + 1));
                final PersistentAttributeAccessMethods attributeMethods = attributeDescriptorMap.get(fieldName);
                // its not a field we have enhanced for interception, so skip it
                if (attributeMethods == null) {
                    continue;
                }
                //System.out.printf( "Transforming access to field [%s] from method [%s]%n", fieldName, methodName );
                log.debugf("Transforming access to field [%s] from method [%s]", fieldName, methodName);
                if (op == Opcode.GETFIELD) {
                    final int methodIndex = MethodWriter.addMethod(constPool, attributeMethods.getReader());
                    itr.writeByte(Opcode.INVOKEVIRTUAL, index);
                    itr.write16bit(methodIndex, index + 1);
                } else {
                    final int methodIndex = MethodWriter.addMethod(constPool, attributeMethods.getWriter());
                    itr.writeByte(Opcode.INVOKEVIRTUAL, index);
                    itr.write16bit(methodIndex, index + 1);
                }
            }
            methodInfo.getCodeAttribute().setAttribute(MapMaker.make(classPool, methodInfo));
        } catch (BadBytecode bb) {
            final String msg = String.format("Unable to perform field access transformation in method [%s]", methodName);
            throw new EnhancementException(msg, bb);
        }
    }
}

Example 2 with CodeIterator

use of javassist.bytecode.CodeIterator in project hibernate-orm by hibernate.

the class PersistentAttributesEnhancer method extendedEnhancement.

// --- //
/**
	 * Replace access to fields of entities (for example, entity.field) with a call to the enhanced getter / setter
	 * (in this example, entity.$$_hibernate_read_field()). It's assumed that the target entity is enhanced as well.
	 *
	 * @param aCtClass Class to enhance (not an entity class).
	 */
public void extendedEnhancement(CtClass aCtClass) {
    final ConstPool constPool = aCtClass.getClassFile().getConstPool();
    final ClassPool classPool = aCtClass.getClassPool();
    for (Object oMethod : aCtClass.getClassFile().getMethods()) {
        final MethodInfo methodInfo = (MethodInfo) oMethod;
        final String methodName = methodInfo.getName();
        // skip methods added by enhancement and abstract methods (methods without any code)
        if (methodName.startsWith("$$_hibernate_") || methodInfo.getCodeAttribute() == null) {
            continue;
        }
        try {
            final CodeIterator itr = methodInfo.getCodeAttribute().iterator();
            while (itr.hasNext()) {
                int index = itr.next();
                int op = itr.byteAt(index);
                if (op != Opcode.PUTFIELD && op != Opcode.GETFIELD) {
                    continue;
                }
                String fieldName = constPool.getFieldrefName(itr.u16bitAt(index + 1));
                String fieldClassName = constPool.getClassInfo(constPool.getFieldrefClass(itr.u16bitAt(index + 1)));
                CtClass targetCtClass = classPool.getCtClass(fieldClassName);
                if (!enhancementContext.isEntityClass(targetCtClass) && !enhancementContext.isCompositeClass(targetCtClass)) {
                    continue;
                }
                if (targetCtClass == aCtClass || !enhancementContext.isPersistentField(targetCtClass.getField(fieldName)) || PersistentAttributesHelper.hasAnnotation(targetCtClass, fieldName, Id.class) || "this$0".equals(fieldName)) {
                    continue;
                }
                log.debugf("Extended enhancement: Transforming access to field [%s.%s] from method [%s#%s]", fieldClassName, fieldName, aCtClass.getName(), methodName);
                if (op == Opcode.GETFIELD) {
                    int fieldReaderMethodIndex = constPool.addMethodrefInfo(constPool.addClassInfo(fieldClassName), EnhancerConstants.PERSISTENT_FIELD_READER_PREFIX + fieldName, "()" + constPool.getFieldrefType(itr.u16bitAt(index + 1)));
                    itr.writeByte(Opcode.INVOKEVIRTUAL, index);
                    itr.write16bit(fieldReaderMethodIndex, index + 1);
                } else {
                    int fieldWriterMethodIndex = constPool.addMethodrefInfo(constPool.addClassInfo(fieldClassName), EnhancerConstants.PERSISTENT_FIELD_WRITER_PREFIX + fieldName, "(" + constPool.getFieldrefType(itr.u16bitAt(index + 1)) + ")V");
                    itr.writeByte(Opcode.INVOKEVIRTUAL, index);
                    itr.write16bit(fieldWriterMethodIndex, index + 1);
                }
            }
            methodInfo.getCodeAttribute().setAttribute(MapMaker.make(classPool, methodInfo));
        } catch (BadBytecode bb) {
            final String msg = String.format("Unable to perform extended enhancement in method [%s]", methodName);
            throw new EnhancementException(msg, bb);
        } catch (NotFoundException nfe) {
            final String msg = String.format("Unable to perform extended enhancement in method [%s]", methodName);
            throw new EnhancementException(msg, nfe);
        }
    }
}

Example 3 with CodeIterator

use of javassist.bytecode.CodeIterator in project pinpoint by naver.

the class JavassistMethod method insertCatch.

private void insertCatch(int from, String src, CtClass exceptionType, String exceptionName) throws CannotCompileException {
    CtClass cc = behavior.getDeclaringClass();
    ConstPool cp = behavior.getMethodInfo().getConstPool();
    CodeAttribute ca = behavior.getMethodInfo().getCodeAttribute();
    CodeIterator iterator = ca.iterator();
    Bytecode b = new Bytecode(cp, ca.getMaxStack(), ca.getMaxLocals());
    b.setStackDepth(1);
    Javac jv = new Javac(b, cc);
    try {
        jv.recordParams(behavior.getParameterTypes(), Modifier.isStatic(getModifiers()));
        jv.recordLocalVariables(ca, from);
        int var = jv.recordVariable(exceptionType, exceptionName);
        b.addAstore(var);
        jv.compileStmnt(src);
        int stack = b.getMaxStack();
        int locals = b.getMaxLocals();
        if (stack > ca.getMaxStack())
            ca.setMaxStack(stack);
        if (locals > ca.getMaxLocals())
            ca.setMaxLocals(locals);
        int len = iterator.getCodeLength();
        int pos = iterator.append(b.get());
        ca.getExceptionTable().add(from, len, len, cp.addClassInfo(exceptionType));
        iterator.append(b.getExceptionTable(), pos);
        behavior.getMethodInfo().rebuildStackMapIf6(cc.getClassPool(), cc.getClassFile2());
    } catch (NotFoundException e) {
        throw new CannotCompileException(e);
    } catch (CompileError e) {
        throw new CannotCompileException(e);
    } catch (BadBytecode e) {
        throw new CannotCompileException(e);
    }
}

Example 4 with CodeIterator

use of javassist.bytecode.CodeIterator in project pinpoint by naver.

the class JavassistMethod method insertBeforeConstructor.

private int insertBeforeConstructor(int pos, String src) throws CannotCompileException {
    CtClass cc = behavior.getDeclaringClass();
    CodeAttribute ca = behavior.getMethodInfo().getCodeAttribute();
    CodeIterator iterator = ca.iterator();
    Bytecode b = new Bytecode(behavior.getMethodInfo().getConstPool(), ca.getMaxStack(), ca.getMaxLocals());
    b.setStackDepth(ca.getMaxStack());
    Javac jv = new Javac(b, cc);
    try {
        jv.recordParams(behavior.getParameterTypes(), false);
        jv.recordLocalVariables(ca, 0);
        jv.compileStmnt(src);
        ca.setMaxStack(b.getMaxStack());
        ca.setMaxLocals(b.getMaxLocals());
        iterator.skipConstructor();
        if (pos != -1) {
            iterator.insertEx(pos, b.get());
        } else {
            pos = iterator.insertEx(b.get());
        }
        iterator.insert(b.getExceptionTable(), pos);
        behavior.getMethodInfo().rebuildStackMapIf6(cc.getClassPool(), cc.getClassFile2());
        return pos + b.length();
    } catch (NotFoundException e) {
        throw new CannotCompileException(e);
    } catch (CompileError e) {
        throw new CannotCompileException(e);
    } catch (BadBytecode e) {
        throw new CannotCompileException(e);
    }
}

Example 5 with CodeIterator

use of javassist.bytecode.CodeIterator in project pinpoint by naver.

the class JavassistMethod method insertBeforeMethod.

private int insertBeforeMethod(int pos, String src) throws CannotCompileException {
    CtClass cc = behavior.getDeclaringClass();
    CodeAttribute ca = behavior.getMethodInfo().getCodeAttribute();
    if (ca == null)
        throw new CannotCompileException("no method body");
    CodeIterator iterator = ca.iterator();
    Javac jv = new Javac(cc);
    try {
        int nvars = jv.recordParams(behavior.getParameterTypes(), Modifier.isStatic(getModifiers()));
        jv.recordParamNames(ca, nvars);
        jv.recordLocalVariables(ca, 0);
        jv.recordType(getReturnType0());
        jv.compileStmnt(src);
        Bytecode b = jv.getBytecode();
        int stack = b.getMaxStack();
        int locals = b.getMaxLocals();
        if (stack > ca.getMaxStack())
            ca.setMaxStack(stack);
        if (locals > ca.getMaxLocals())
            ca.setMaxLocals(locals);
        if (pos != -1) {
            iterator.insertEx(pos, b.get());
        } else {
            pos = iterator.insertEx(b.get());
        }
        iterator.insert(b.getExceptionTable(), pos);
        behavior.getMethodInfo().rebuildStackMapIf6(cc.getClassPool(), cc.getClassFile2());
        return pos + b.length();
    } catch (NotFoundException e) {
        throw new CannotCompileException(e);
    } catch (CompileError e) {
        throw new CannotCompileException(e);
    } catch (BadBytecode e) {
        throw new CannotCompileException(e);
    }
}