Java Code Examples for org.springframework.expression.spel.CodeFlow#lastDescriptor()

/**
 * Ask an argument to generate its bytecode and then follow it up
 * with any boxing/unboxing/checkcasting to ensure it matches the expected parameter descriptor.
 */
protected static void generateCodeForArgument(MethodVisitor mv, CodeFlow cf, SpelNodeImpl argument, String paramDesc) {
	cf.enterCompilationScope();
	argument.generateCode(mv, cf);
	String lastDesc = cf.lastDescriptor();
	Assert.state(lastDesc != null, "No last descriptor");
	boolean primitiveOnStack = CodeFlow.isPrimitive(lastDesc);
	// Check if need to box it for the method reference?
	if (primitiveOnStack && paramDesc.charAt(0) == 'L') {
		CodeFlow.insertBoxIfNecessary(mv, lastDesc.charAt(0));
	}
	else if (paramDesc.length() == 1 && !primitiveOnStack) {
		CodeFlow.insertUnboxInsns(mv, paramDesc.charAt(0), lastDesc);
	}
	else if (!paramDesc.equals(lastDesc)) {
		// This would be unnecessary in the case of subtyping (e.g. method takes Number but Integer passed in)
		CodeFlow.insertCheckCast(mv, paramDesc);
	}
	cf.exitCompilationScope();
}
 

/**
 * Ask an argument to generate its bytecode and then follow it up
 * with any boxing/unboxing/checkcasting to ensure it matches the expected parameter descriptor.
 */
protected static void generateCodeForArgument(MethodVisitor mv, CodeFlow cf, SpelNodeImpl argument, String paramDesc) {
	cf.enterCompilationScope();
	argument.generateCode(mv, cf);
	String lastDesc = cf.lastDescriptor();
	boolean primitiveOnStack = CodeFlow.isPrimitive(lastDesc);
	// Check if need to box it for the method reference?
	if (primitiveOnStack && paramDesc.charAt(0) == 'L') {
		CodeFlow.insertBoxIfNecessary(mv, lastDesc.charAt(0));
	}
	else if (paramDesc.length() == 1 && !primitiveOnStack) {
		CodeFlow.insertUnboxInsns(mv, paramDesc.charAt(0), lastDesc);
	}
	else if (!paramDesc.equals(lastDesc)) {
		// This would be unnecessary in the case of subtyping (e.g. method takes Number but Integer passed in)
		CodeFlow.insertCheckCast(mv, paramDesc);
	}
	cf.exitCompilationScope();
}
 

/**
 * Ask an argument to generate its bytecode and then follow it up
 * with any boxing/unboxing/checkcasting to ensure it matches the expected parameter descriptor.
 */
protected static void generateCodeForArgument(MethodVisitor mv, CodeFlow cf, SpelNodeImpl argument, String paramDesc) {
	cf.enterCompilationScope();
	argument.generateCode(mv, cf);
	String lastDesc = cf.lastDescriptor();
	Assert.state(lastDesc != null, "No last descriptor");
	boolean primitiveOnStack = CodeFlow.isPrimitive(lastDesc);
	// Check if need to box it for the method reference?
	if (primitiveOnStack && paramDesc.charAt(0) == 'L') {
		CodeFlow.insertBoxIfNecessary(mv, lastDesc.charAt(0));
	}
	else if (paramDesc.length() == 1 && !primitiveOnStack) {
		CodeFlow.insertUnboxInsns(mv, paramDesc.charAt(0), lastDesc);
	}
	else if (!paramDesc.equals(lastDesc)) {
		// This would be unnecessary in the case of subtyping (e.g. method takes Number but Integer passed in)
		CodeFlow.insertCheckCast(mv, paramDesc);
	}
	cf.exitCompilationScope();
}
 

@Override
public void generateCode(String propertyName, MethodVisitor mv, CodeFlow cf) {
    String descriptor = cf.lastDescriptor();
    if (descriptor == null || !descriptor.equals("Ljava/util/Map")) {
        if (descriptor == null) {
            cf.loadTarget(mv);
        }
        CodeFlow.insertCheckCast(mv, "Ljava/util/Map");
    }
    mv.visitLdcInsn(propertyName);
    mv.visitMethodInsn(INVOKEINTERFACE, "java/util/Map", "get", "(Ljava/lang/Object;)Ljava/lang/Object;", true);
}
 

@Override
public void generateCode(String propertyName, MethodVisitor mv, CodeFlow cf) {
	String descriptor = cf.lastDescriptor();
	if (descriptor == null || !descriptor.equals("Ljava/util/Map")) {
		if (descriptor == null) {
			cf.loadTarget(mv);
		}
		CodeFlow.insertCheckCast(mv, "Ljava/util/Map");
	}
	mv.visitLdcInsn(propertyName);
	mv.visitMethodInsn(INVOKEINTERFACE, "java/util/Map", "get","(Ljava/lang/Object;)Ljava/lang/Object;",true);
}
 

@Override
public void generateCode(String propertyName, MethodVisitor mv, CodeFlow cf) {
	boolean isStatic = Modifier.isStatic(this.member.getModifiers());
	String descriptor = cf.lastDescriptor();
	String classDesc = this.member.getDeclaringClass().getName().replace('.', '/');

	if (!isStatic) {
		if (descriptor == null) {
			cf.loadTarget(mv);
		}
		if (descriptor == null || !classDesc.equals(descriptor.substring(1))) {
			mv.visitTypeInsn(CHECKCAST, classDesc);
		}
	}
	else {
		if (descriptor != null) {
			// A static field/method call will not consume what is on the stack,
			// it needs to be popped off.
			mv.visitInsn(POP);
		}
	}

	if (this.member instanceof Method) {
		mv.visitMethodInsn((isStatic ? INVOKESTATIC : INVOKEVIRTUAL), classDesc, this.member.getName(),
				CodeFlow.createSignatureDescriptor((Method) this.member), false);
	}
	else {
		mv.visitFieldInsn((isStatic ? GETSTATIC : GETFIELD), classDesc, this.member.getName(),
				CodeFlow.toJvmDescriptor(((Field) this.member).getType()));
	}
}
 

@Override
public void generateCode(String propertyName, MethodVisitor mv, CodeFlow cf) {
	String descriptor = cf.lastDescriptor();
	if (descriptor == null || !descriptor.equals("Ljava/util/Map")) {
		if (descriptor == null) {
			cf.loadTarget(mv);
		}
		CodeFlow.insertCheckCast(mv, "Ljava/util/Map");
	}
	mv.visitLdcInsn(propertyName);
	mv.visitMethodInsn(INVOKEINTERFACE, "java/util/Map", "get","(Ljava/lang/Object;)Ljava/lang/Object;",true);
}
 

@Override
public void generateCode(String propertyName, MethodVisitor mv, CodeFlow cf) {
	boolean isStatic = Modifier.isStatic(this.member.getModifiers());
	String descriptor = cf.lastDescriptor();
	String classDesc = this.member.getDeclaringClass().getName().replace('.', '/');

	if (!isStatic) {
		if (descriptor == null) {
			cf.loadTarget(mv);
		}
		if (descriptor == null || !classDesc.equals(descriptor.substring(1))) {
			mv.visitTypeInsn(CHECKCAST, classDesc);
		}
	}
	else {
		if (descriptor != null) {
			// A static field/method call will not consume what is on the stack,
			// it needs to be popped off.
			mv.visitInsn(POP);
		}
	}

	if (this.member instanceof Method) {
		mv.visitMethodInsn((isStatic ? INVOKESTATIC : INVOKEVIRTUAL), classDesc, this.member.getName(),
				CodeFlow.createSignatureDescriptor((Method) this.member), false);
	}
	else {
		mv.visitFieldInsn((isStatic ? GETSTATIC : GETFIELD), classDesc, this.member.getName(),
				CodeFlow.toJvmDescriptor(((Field) this.member).getType()));
	}
}
 

@Override
public void generateCode(String propertyName, MethodVisitor mv, CodeFlow cf) {
	String descriptor = cf.lastDescriptor();
	if (descriptor == null || !descriptor.equals("Ljava/util/Map")) {
		if (descriptor == null) {
			cf.loadTarget(mv);
		}
		CodeFlow.insertCheckCast(mv, "Ljava/util/Map");
	}
	mv.visitLdcInsn(propertyName);
	mv.visitMethodInsn(INVOKEINTERFACE, "java/util/Map", "get","(Ljava/lang/Object;)Ljava/lang/Object;",true);
}
 

@Override
public void generateCode(String propertyName, MethodVisitor mv, CodeFlow cf) {
	boolean isStatic = Modifier.isStatic(this.member.getModifiers());
	String descriptor = cf.lastDescriptor();
	String classDesc = this.member.getDeclaringClass().getName().replace('.', '/');

	if (!isStatic) {
		if (descriptor == null) {
			cf.loadTarget(mv);
		}
		if (descriptor == null || !classDesc.equals(descriptor.substring(1))) {
			mv.visitTypeInsn(CHECKCAST, classDesc);
		}
	}
	else {
		if (descriptor != null) {
			// A static field/method call will not consume what is on the stack,
			// it needs to be popped off.
			mv.visitInsn(POP);
		}
	}

	if (this.member instanceof Method) {
		mv.visitMethodInsn((isStatic ? INVOKESTATIC : INVOKEVIRTUAL), classDesc, this.member.getName(),
				CodeFlow.createSignatureDescriptor((Method) this.member), false);
	}
	else {
		mv.visitFieldInsn((isStatic ? GETSTATIC : GETFIELD), classDesc, this.member.getName(),
				CodeFlow.toJvmDescriptor(((Field) this.member).getType()));
	}
}
 

@Override
public void generateCode(MethodVisitor mv, CodeFlow cf) {
	// exit type descriptor can be null if both components are literal expressions
	computeExitTypeDescriptor();
	cf.enterCompilationScope();
	this.children[0].generateCode(mv, cf);
	String lastDesc = cf.lastDescriptor();
	Assert.state(lastDesc != null, "No last descriptor");
	CodeFlow.insertBoxIfNecessary(mv, lastDesc.charAt(0));
	cf.exitCompilationScope();
	Label elseTarget = new Label();
	Label endOfIf = new Label();
	mv.visitInsn(DUP);
	mv.visitJumpInsn(IFNULL, elseTarget);
	// Also check if empty string, as per the code in the interpreted version
	mv.visitInsn(DUP);
	mv.visitLdcInsn("");
	mv.visitInsn(SWAP);
	mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/String", "equals", "(Ljava/lang/Object;)Z",false);
	mv.visitJumpInsn(IFEQ, endOfIf);  // if not empty, drop through to elseTarget
	mv.visitLabel(elseTarget);
	mv.visitInsn(POP);
	cf.enterCompilationScope();
	this.children[1].generateCode(mv, cf);
	if (!CodeFlow.isPrimitive(this.exitTypeDescriptor)) {
		lastDesc = cf.lastDescriptor();
		Assert.state(lastDesc != null, "No last descriptor");
		CodeFlow.insertBoxIfNecessary(mv, lastDesc.charAt(0));
	}
	cf.exitCompilationScope();
	mv.visitLabel(endOfIf);
	cf.pushDescriptor(this.exitTypeDescriptor);
}
 

void generateClinitCode(String clazzname, String constantFieldName, MethodVisitor mv, CodeFlow codeflow, boolean nested) {
	mv.visitTypeInsn(NEW, "java/util/ArrayList");
	mv.visitInsn(DUP);
	mv.visitMethodInsn(INVOKESPECIAL, "java/util/ArrayList", "<init>", "()V", false);
	if (!nested) {
		mv.visitFieldInsn(PUTSTATIC, clazzname, constantFieldName, "Ljava/util/List;");
	}
	int childCount = getChildCount();
	for (int c = 0; c < childCount; c++) {
		if (!nested) {
			mv.visitFieldInsn(GETSTATIC, clazzname, constantFieldName, "Ljava/util/List;");
		}
		else {
			mv.visitInsn(DUP);
		}
		// The children might be further lists if they are not constants. In this
		// situation do not call back into generateCode() because it will register another clinit adder.
		// Instead, directly build the list here:
		if (this.children[c] instanceof InlineList) {
			((InlineList)this.children[c]).generateClinitCode(clazzname, constantFieldName, mv, codeflow, true);
		}
		else {
			this.children[c].generateCode(mv, codeflow);
			String lastDesc = codeflow.lastDescriptor();
			if (CodeFlow.isPrimitive(lastDesc)) {
				CodeFlow.insertBoxIfNecessary(mv, lastDesc.charAt(0));
			}
		}
		mv.visitMethodInsn(INVOKEINTERFACE, "java/util/List", "add", "(Ljava/lang/Object;)Z", true);
		mv.visitInsn(POP);
	}
}
 

@Override
public void generateCode(MethodVisitor mv, CodeFlow cf) {
	// May reach here without it computed if all elements are literals
	computeExitTypeDescriptor();
	cf.enterCompilationScope();
	this.children[0].generateCode(mv, cf);
	String lastDesc = cf.lastDescriptor();
	Assert.state(lastDesc != null, "No last descriptor");
	if (!CodeFlow.isPrimitive(lastDesc)) {
		CodeFlow.insertUnboxInsns(mv, 'Z', lastDesc);
	}
	cf.exitCompilationScope();
	Label elseTarget = new Label();
	Label endOfIf = new Label();
	mv.visitJumpInsn(IFEQ, elseTarget);
	cf.enterCompilationScope();
	this.children[1].generateCode(mv, cf);
	if (!CodeFlow.isPrimitive(this.exitTypeDescriptor)) {
		lastDesc = cf.lastDescriptor();
		Assert.state(lastDesc != null, "No last descriptor");
		CodeFlow.insertBoxIfNecessary(mv, lastDesc.charAt(0));
	}
	cf.exitCompilationScope();
	mv.visitJumpInsn(GOTO, endOfIf);
	mv.visitLabel(elseTarget);
	cf.enterCompilationScope();
	this.children[2].generateCode(mv, cf);
	if (!CodeFlow.isPrimitive(this.exitTypeDescriptor)) {
		lastDesc = cf.lastDescriptor();
		Assert.state(lastDesc != null, "No last descriptor");
		CodeFlow.insertBoxIfNecessary(mv, lastDesc.charAt(0));
	}
	cf.exitCompilationScope();
	mv.visitLabel(endOfIf);
	cf.pushDescriptor(this.exitTypeDescriptor);
}
 

@Override
public void generateCode(String propertyName, MethodVisitor mv, CodeFlow cf) {
	String descriptor = cf.lastDescriptor();
	if (descriptor == null || !descriptor.equals("Ljava/util/Map")) {
		if (descriptor == null) {
			cf.loadTarget(mv);
		}
		CodeFlow.insertCheckCast(mv, "Ljava/util/Map");
	}
	mv.visitLdcInsn(propertyName);
	mv.visitMethodInsn(INVOKEINTERFACE, "java/util/Map", "get","(Ljava/lang/Object;)Ljava/lang/Object;",true);
}
 

@Override
public void generateCode(String propertyName, MethodVisitor mv, CodeFlow cf) {
	boolean isStatic = Modifier.isStatic(this.member.getModifiers());
	String descriptor = cf.lastDescriptor();
	String classDesc = this.member.getDeclaringClass().getName().replace('.', '/');

	if (!isStatic) {
		if (descriptor == null) {
			cf.loadTarget(mv);
		}
		if (descriptor == null || !classDesc.equals(descriptor.substring(1))) {
			mv.visitTypeInsn(CHECKCAST, classDesc);
		}
	}
	else {
		if (descriptor != null) {
			// A static field/method call will not consume what is on the stack,
			// it needs to be popped off.
			mv.visitInsn(POP);
		}
	}

	if (this.member instanceof Method) {
		mv.visitMethodInsn((isStatic ? INVOKESTATIC : INVOKEVIRTUAL), classDesc, this.member.getName(),
				CodeFlow.createSignatureDescriptor((Method) this.member), false);
	}
	else {
		mv.visitFieldInsn((isStatic ? GETSTATIC : GETFIELD), classDesc, this.member.getName(),
				CodeFlow.toJvmDescriptor(((Field) this.member).getType()));
	}
}
 

@Override
public void generateCode(MethodVisitor mv, CodeFlow cf) {
	// exit type descriptor can be null if both components are literal expressions
	computeExitTypeDescriptor();
	cf.enterCompilationScope();
	this.children[0].generateCode(mv, cf);
	String lastDesc = cf.lastDescriptor();
	Assert.state(lastDesc != null, "No last descriptor");
	CodeFlow.insertBoxIfNecessary(mv, lastDesc.charAt(0));
	cf.exitCompilationScope();
	Label elseTarget = new Label();
	Label endOfIf = new Label();
	mv.visitInsn(DUP);
	mv.visitJumpInsn(IFNULL, elseTarget);
	// Also check if empty string, as per the code in the interpreted version
	mv.visitInsn(DUP);
	mv.visitLdcInsn("");
	mv.visitInsn(SWAP);
	mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/String", "equals", "(Ljava/lang/Object;)Z",false);
	mv.visitJumpInsn(IFEQ, endOfIf);  // if not empty, drop through to elseTarget
	mv.visitLabel(elseTarget);
	mv.visitInsn(POP);
	cf.enterCompilationScope();
	this.children[1].generateCode(mv, cf);
	if (!CodeFlow.isPrimitive(this.exitTypeDescriptor)) {
		lastDesc = cf.lastDescriptor();
		Assert.state(lastDesc != null, "No last descriptor");
		CodeFlow.insertBoxIfNecessary(mv, lastDesc.charAt(0));
	}
	cf.exitCompilationScope();
	mv.visitLabel(endOfIf);
	cf.pushDescriptor(this.exitTypeDescriptor);
}
 

void generateClinitCode(String clazzname, String constantFieldName, MethodVisitor mv, CodeFlow codeflow, boolean nested) {
	mv.visitTypeInsn(NEW, "java/util/ArrayList");
	mv.visitInsn(DUP);
	mv.visitMethodInsn(INVOKESPECIAL, "java/util/ArrayList", "<init>", "()V", false);
	if (!nested) {
		mv.visitFieldInsn(PUTSTATIC, clazzname, constantFieldName, "Ljava/util/List;");
	}
	int childCount = getChildCount();
	for (int c = 0; c < childCount; c++) {
		if (!nested) {
			mv.visitFieldInsn(GETSTATIC, clazzname, constantFieldName, "Ljava/util/List;");
		}
		else {
			mv.visitInsn(DUP);
		}
		// The children might be further lists if they are not constants. In this
		// situation do not call back into generateCode() because it will register another clinit adder.
		// Instead, directly build the list here:
		if (this.children[c] instanceof InlineList) {
			((InlineList)this.children[c]).generateClinitCode(clazzname, constantFieldName, mv, codeflow, true);
		}
		else {
			this.children[c].generateCode(mv, codeflow);
			String lastDesc = codeflow.lastDescriptor();
			if (CodeFlow.isPrimitive(lastDesc)) {
				CodeFlow.insertBoxIfNecessary(mv, lastDesc.charAt(0));
			}
		}
		mv.visitMethodInsn(INVOKEINTERFACE, "java/util/List", "add", "(Ljava/lang/Object;)Z", true);
		mv.visitInsn(POP);
	}
}
 

@Override
public void generateCode(MethodVisitor mv, CodeFlow cf) {
	// May reach here without it computed if all elements are literals
	computeExitTypeDescriptor();
	cf.enterCompilationScope();
	this.children[0].generateCode(mv, cf);
	String lastDesc = cf.lastDescriptor();
	Assert.state(lastDesc != null, "No last descriptor");
	if (!CodeFlow.isPrimitive(lastDesc)) {
		CodeFlow.insertUnboxInsns(mv, 'Z', lastDesc);
	}
	cf.exitCompilationScope();
	Label elseTarget = new Label();
	Label endOfIf = new Label();
	mv.visitJumpInsn(IFEQ, elseTarget);
	cf.enterCompilationScope();
	this.children[1].generateCode(mv, cf);
	if (!CodeFlow.isPrimitive(this.exitTypeDescriptor)) {
		lastDesc = cf.lastDescriptor();
		Assert.state(lastDesc != null, "No last descriptor");
		CodeFlow.insertBoxIfNecessary(mv, lastDesc.charAt(0));
	}
	cf.exitCompilationScope();
	mv.visitJumpInsn(GOTO, endOfIf);
	mv.visitLabel(elseTarget);
	cf.enterCompilationScope();
	this.children[2].generateCode(mv, cf);
	if (!CodeFlow.isPrimitive(this.exitTypeDescriptor)) {
		lastDesc = cf.lastDescriptor();
		Assert.state(lastDesc != null, "No last descriptor");
		CodeFlow.insertBoxIfNecessary(mv, lastDesc.charAt(0));
	}
	cf.exitCompilationScope();
	mv.visitLabel(endOfIf);
	cf.pushDescriptor(this.exitTypeDescriptor);
}
 

@Override
public void generateCode(MethodVisitor mv, CodeFlow cf) {
	CachedMethodExecutor executorToCheck = this.cachedExecutor;
	if (executorToCheck == null || !(executorToCheck.get() instanceof ReflectiveMethodExecutor)) {
		throw new IllegalStateException("No applicable cached executor found: " + executorToCheck);
	}

	ReflectiveMethodExecutor methodExecutor = (ReflectiveMethodExecutor) executorToCheck.get();
	Method method = methodExecutor.getMethod();
	boolean isStaticMethod = Modifier.isStatic(method.getModifiers());
	String descriptor = cf.lastDescriptor();

	if (descriptor == null) {
		if (!isStaticMethod) {
			// Nothing on the stack but something is needed
			cf.loadTarget(mv);
		}
	}
	else {
		if (isStaticMethod) {
			// Something on the stack when nothing is needed
			mv.visitInsn(POP);
		}
	}
	
	if (CodeFlow.isPrimitive(descriptor)) {
		CodeFlow.insertBoxIfNecessary(mv, descriptor.charAt(0));
	}

	String classDesc = (Modifier.isPublic(method.getDeclaringClass().getModifiers()) ?
			method.getDeclaringClass().getName().replace('.', '/') :
			methodExecutor.getPublicDeclaringClass().getName().replace('.', '/'));
	if (!isStaticMethod) {
		if (descriptor == null || !descriptor.substring(1).equals(classDesc)) {
			CodeFlow.insertCheckCast(mv, "L" + classDesc);
		}
	}

	generateCodeForArguments(mv, cf, method, this.children);
	mv.visitMethodInsn((isStaticMethod ? INVOKESTATIC : INVOKEVIRTUAL), classDesc, method.getName(),
			CodeFlow.createSignatureDescriptor(method), method.getDeclaringClass().isInterface());
	cf.pushDescriptor(this.exitTypeDescriptor);
}
 

@Override
public void generateCode(MethodVisitor mv, CodeFlow cf) {
	CachedMethodExecutor executorToCheck = this.cachedExecutor;
	if (executorToCheck == null || !(executorToCheck.get() instanceof ReflectiveMethodExecutor)) {
		throw new IllegalStateException("No applicable cached executor found: " + executorToCheck);
	}

	ReflectiveMethodExecutor methodExecutor = (ReflectiveMethodExecutor) executorToCheck.get();
	Method method = methodExecutor.getMethod();
	boolean isStaticMethod = Modifier.isStatic(method.getModifiers());
	String descriptor = cf.lastDescriptor();

	if (descriptor == null) {
		if (!isStaticMethod) {
			// Nothing on the stack but something is needed
			cf.loadTarget(mv);
		}
	}
	else {
		if (isStaticMethod) {
			// Something on the stack when nothing is needed
			mv.visitInsn(POP);
		}
	}
	
	if (CodeFlow.isPrimitive(descriptor)) {
		CodeFlow.insertBoxIfNecessary(mv, descriptor.charAt(0));
	}

	String classDesc = (Modifier.isPublic(method.getDeclaringClass().getModifiers()) ?
			method.getDeclaringClass().getName().replace('.', '/') :
			methodExecutor.getPublicDeclaringClass().getName().replace('.', '/'));
	if (!isStaticMethod) {
		if (descriptor == null || !descriptor.substring(1).equals(classDesc)) {
			CodeFlow.insertCheckCast(mv, "L" + classDesc);
		}
	}

	generateCodeForArguments(mv, cf, method, this.children);
	mv.visitMethodInsn((isStaticMethod ? INVOKESTATIC : INVOKEVIRTUAL), classDesc, method.getName(),
			CodeFlow.createSignatureDescriptor(method), method.getDeclaringClass().isInterface());
	cf.pushDescriptor(this.exitTypeDescriptor);
}