feat: initial implementation of new system

- multiple injectors/target
- removed strict limitation of one patch per class
- made finders far smarter
- added boolean for obfuscation environment (currently never changed from default)

1 files changed, 378 insertions, 120 deletions

diff --git a/src/main/java/ftbsc/lll/processor/LilleroProcessor.java b/src/main/java/ftbsc/lll/processor/LilleroProcessor.java
index 501200a..0277211 100644
--- a/src/main/java/ftbsc/lll/processor/LilleroProcessor.java
+++ b/src/main/java/ftbsc/lll/processor/LilleroProcessor.java
@@ -2,33 +2,30 @@ package ftbsc.lll.processor;
 
 import com.squareup.javapoet.*;
 import ftbsc.lll.IInjector;
+import ftbsc.lll.exceptions.AmbiguousDefinitionException;
+import ftbsc.lll.exceptions.MappingNotFoundException;
+import ftbsc.lll.exceptions.TargetNotFoundException;
 import ftbsc.lll.processor.annotations.*;
+import ftbsc.lll.processor.tools.SrgMapper;
 import ftbsc.lll.proxies.FieldProxy;
 import ftbsc.lll.proxies.MethodProxy;
-import ftbsc.lll.tools.SrgMapper;
 
 import javax.annotation.processing.*;
 import javax.lang.model.SourceVersion;
 import javax.lang.model.element.*;
 import javax.lang.model.type.ExecutableType;
-import javax.lang.model.type.MirroredTypeException;
 import javax.lang.model.type.TypeMirror;
 import javax.tools.Diagnostic;
 import javax.tools.FileObject;
 import javax.tools.JavaFileObject;
 import javax.tools.StandardLocation;
 import java.io.*;
-import java.lang.reflect.Field;
-import java.lang.reflect.Method;
 import java.net.URL;
 import java.nio.charset.StandardCharsets;
-import java.util.ArrayList;
-import java.util.HashSet;
-import java.util.List;
-import java.util.Set;
+import java.util.*;
 import java.util.stream.Collectors;
 
-import static ftbsc.lll.processor.ASTUtils.*;
+import static ftbsc.lll.processor.tools.ASTUtils.*;
 
 /**
  * The actual annotation processor behind the magic.
@@ -44,6 +41,11 @@ public class LilleroProcessor extends AbstractProcessor {
 	private final Set<String> generatedInjectors = new HashSet<>();
 
 	/**
+	 * A static boolean that should be set to true when ran in a non-obfuscated environment.
+	 */
+	public static boolean obfuscatedEnvironment = false; //todo: set this
+
+	/**
 	 * Where the actual processing happens.
 	 * It filters through whatever annotated class it's fed, and checks whether it contains
 	 * the required information. It then generates injectors and a service provider for every
@@ -64,7 +66,7 @@ public class LilleroProcessor extends AbstractProcessor {
 						.filter(this::isValidInjector)
 						.collect(Collectors.toSet());
 				if(!validInjectors.isEmpty()) {
-					validInjectors.forEach(this::generateInjector);
+					validInjectors.forEach(this::generateInjectors);
 					if (!this.generatedInjectors.isEmpty()) {
 						generateServiceProvider();
 						return true;
@@ -102,11 +104,190 @@ public class LilleroProcessor extends AbstractProcessor {
 	}
 
 	/**
-	 * Generates the Injector corresponding to the given class.
+	 * Finds the class name and maps it to the correct format.
+	 * @param patchAnn the {@link Patch} annotation containing target class info
+	 * @param methodAnn the {@link FindMethod} annotation to fall back on, may be null
+	 * @param mapper the {@link SrgMapper} to use
+	 * @implNote De facto, there is never any difference between the SRG and MCP name of a class.
+	 *           In theory, differences only arise between SRG/MCP names and Notch (fully obfuscated)
+	 *           names. However, this method still performs a conversion - just in case there is an
+	 *           odd one out.
+	 * @return the fully qualified class name
+	 * @since 0.3.0
+	 */
+	private static String findClassName(Patch patchAnn, FindMethod methodAnn, SrgMapper mapper) {
+		String fullyQualifiedName =
+			methodAnn == null || methodAnn.parent() == Object.class
+				? getClassFullyQualifiedName(patchAnn.value())
+				: getClassFullyQualifiedName(methodAnn.parent());
+		return mapper.mapClass(fullyQualifiedName, obfuscatedEnvironment).replace('/', '.');
+	}
+
+	/**
+	 * Finds the class name and maps it to the correct format.
+	 * @param patchAnn the {@link Patch} annotation containing target class info
+	 * @param mapper the {@link SrgMapper} to use
+	 * @return the internal class name
+	 * @since 0.3.0
+	 */
+	private static String findClassName(Patch patchAnn, SrgMapper mapper) {
+		return findClassName(patchAnn, null, mapper);
+	}
+
+	/**
+	 * Finds the method name and maps it to the correct format.
+	 * @param parentFQN the already mapped FQN of the parent class
+	 * @param methodAnn the {@link FindMethod} annotation to fall back on, may be null
+	 * @param stub the {@link ExecutableElement} for the stub
+	 * @param mapper the {@link SrgMapper} to use
+	 * @return the internal class name
+	 * @since 0.3.0
+	 */
+	private static String findMethodName(String parentFQN, FindMethod methodAnn, ExecutableElement stub, SrgMapper mapper) {
+		String methodName = methodAnn == null ? stub.getSimpleName().toString() : methodAnn.name();
+		try {
+			methodName = mapper.mapMember(
+				parentFQN,
+				methodName,
+				obfuscatedEnvironment
+			);
+		} catch(MappingNotFoundException e) {
+			//not found: try again with the name of the annotated method
+			if(methodAnn == null) {
+				methodName = mapper.mapMember(
+					parentFQN,
+					stub.getSimpleName().toString(),
+					obfuscatedEnvironment
+				);
+			} else throw e;
+		}
+		return methodName;
+	}
+
+	/**
+	 * Finds the method name and maps it to the correct format.
+	 * @param patchAnn the {@link Patch} annotation containing target class info
+	 * @param methodAnn the {@link FindMethod} annotation to fall back on, may be null
+	 * @param stub the {@link ExecutableElement} for the stub
+	 * @param mapper the {@link SrgMapper} to use
+	 * @return the internal class name
+	 * @since 0.3.0
+	 */
+	private static String findMethodName(Patch patchAnn, FindMethod methodAnn, ExecutableElement stub, SrgMapper mapper) {
+		return findMethodName(findClassName(patchAnn, methodAnn, mapper), methodAnn, stub, mapper);
+	}
+
+	/**
+	 * Finds a method given name, container and descriptor.
+	 * @param fullyQualifiedNameParent the fully qualified name of the parent class of the method
+	 * @param name the name to search for
+	 * @param descr the descriptor to search for
+	 * @param strict whether the search should be strict (see {@link Target#strict()} for more info)
+	 * @return the desired method, if it exists
+	 * @throws AmbiguousDefinitionException if it finds more than one candidate
+	 * @throws TargetNotFoundException if it finds no valid candidate
+	 * @since 0.3.0
+	 */
+	private ExecutableElement findMethod(String fullyQualifiedNameParent, String name, String descr, boolean strict) {
+		TypeElement parent = processingEnv.getElementUtils().getTypeElement(fullyQualifiedNameParent);
+		if(parent == null)
+			throw new AmbiguousDefinitionException("Could not find parent class " + fullyQualifiedNameParent + "!");
+
+		//try to find by name
+		List<ExecutableElement> candidates = parent.getEnclosedElements()
+			.stream()
+			.filter(e -> e instanceof ExecutableElement)
+			.map(e -> (ExecutableElement) e)
+			.filter(e -> e.getSimpleName().contentEquals(name))
+			.collect(Collectors.toList());
+		if(candidates.size() == 0)
+			throw new TargetNotFoundException(name + " " + descr);
+		if(candidates.size() == 1 && !strict)
+			return candidates.get(0);
+		if(descr == null) {
+			throw new AmbiguousDefinitionException(
+				"Found " + candidates.size()
+					+ " methods named " + name
+					+ " in class " + fullyQualifiedNameParent + "!"
+			);
+		} else {
+			candidates = candidates.stream()
+				.filter(strict
+					? c -> descr.equals(descriptorFromExecutableElement(c))
+					: c -> descr.split("\\)")[0].equalsIgnoreCase(descriptorFromExecutableElement(c).split("\\)")[0])
+				).collect(Collectors.toList());
+			if(candidates.size() == 0)
+				throw new TargetNotFoundException(name + " " + descr);
+			if(candidates.size() > 1)
+				throw new AmbiguousDefinitionException(
+					"Found " + candidates.size()
+						+ " methods named " + name
+						+ " in class " + fullyQualifiedNameParent + "!"
+				);
+			return candidates.get(0);
+		}
+	}
+
+	/**
+	 * Finds the real method corresponding to a stub.
+	 * @param stub the {@link ExecutableElement} for the stub
+	 * @param mapper the {@link SrgMapper} to use
+	 * @return the desired method, if it exists
+	 * @throws AmbiguousDefinitionException if it finds more than one candidate
+	 * @throws TargetNotFoundException if it finds no valid candidate
+	 * @since 0.3.0
+	 */
+	private ExecutableElement findRealMethod(ExecutableElement stub, SrgMapper mapper) {
+		Patch patchAnn = stub.getEnclosingElement().getAnnotation(Patch.class);
+		FindMethod findAnn = stub.getAnnotation(FindMethod.class); //this may be null, it means no fallback info
+		Target target = stub.getAnnotation(Target.class); //if this is null strict mode is always disabled
+		String parentFQN = findClassName(patchAnn, findAnn, mapper);
+		String methodName = findMethodName(patchAnn, findAnn, stub, mapper);
+		return findMethod(
+			parentFQN,
+			methodName,
+			descriptorFromExecutableElement(stub),
+			target != null && target.strict());
+	}
+
+	/**
+	 * Finds the real field corresponding to a stub.
+	 * @param stub the {@link ExecutableElement} for the stub
+	 * @param mapper the {@link SrgMapper} to use
+	 * @return the desired method, if it exists
+	 * @throws TargetNotFoundException if it finds no valid candidate
+	 * @since 0.3.0
+	 */
+	private VariableElement findField(ExecutableElement stub, SrgMapper mapper) {
+		Patch patchAnn = stub.getEnclosingElement().getAnnotation(Patch.class);
+		FindField fieldAnn = stub.getAnnotation(FindField.class);
+		String parentName = mapper.mapClass(getClassFullyQualifiedName(
+			fieldAnn.parent().equals(Object.class)
+				? patchAnn.value()
+				: fieldAnn.parent()
+		), obfuscatedEnvironment);
+		String name = fieldAnn.name().equals("")
+			? stub.getSimpleName().toString()
+			: fieldAnn.name();
+		TypeElement parent = processingEnv.getElementUtils().getTypeElement(parentName);
+		List<VariableElement> candidates =
+			parent.getEnclosedElements()
+				.stream()
+				.filter(f -> f instanceof VariableElement)
+				.filter(f -> f.getSimpleName().contentEquals(name))
+				.map(f -> (VariableElement) f)
+				.collect(Collectors.toList());
+		if(candidates.size() == 0)
+			throw new TargetNotFoundException(stub.getSimpleName().toString());
+		else return candidates.get(0); //there can only ever be one
+	}
+
+	/**
+	 * Generates the Injector(s) contained in the given class.
 	 * Basically implements the {@link IInjector} interface for you.
 	 * @param cl the {@link TypeElement} for the given class
 	 */
-	private void generateInjector(TypeElement cl) {
+	private void generateInjectors(TypeElement cl) {
 		SrgMapper mapper;
 		try { //TODO: cant we get it from local?
 			URL url = new URL("https://data.fantabos.co/output.tsrg");
@@ -116,79 +297,149 @@ public class LilleroProcessor extends AbstractProcessor {
 			is.close();
 		} catch(IOException e) {
 			throw new RuntimeException("Could not open the specified TSRG file!", e);
-		}
+		} //todo attempt to proceed without mappings
 
-		Patch ann = cl.getAnnotation(Patch.class);
-		String targetClassCanonicalName;
-		try {
-			targetClassCanonicalName = ann.value().getCanonicalName();
-		} catch(MirroredTypeException e) {
-			targetClassCanonicalName = e.getTypeMirror().toString();
-		} //pretty sure class names de facto never change but better safe than sorry
-		String targetClassSrgName = mapper.getMcpClass(targetClassCanonicalName.replace('.', '/'));
-
-		ExecutableElement targetMethod = findAnnotatedMethods(cl, Target.class).get(0); //there should only be one
-		String targetMethodDescriptor = descriptorFromMethodSpec(targetMethod);
-		String targetMethodSrgName = mapper.getSrgMember(
-			targetClassCanonicalName.replace('.', '/'),
-			targetMethod.getSimpleName() + " " + targetMethodDescriptor
-		);
-
-		ExecutableElement injectorMethod = findAnnotatedMethods(cl, Injector.class).get(0); //there should only be one
+		//find class information
+		Patch patchAnn = cl.getAnnotation(Patch.class);
+		String targetClassSrgName = findClassName(patchAnn, mapper);
 
+		//find package information
 		Element packageElement = cl.getEnclosingElement();
 		while (packageElement.getKind() != ElementKind.PACKAGE)
 			packageElement = packageElement.getEnclosingElement();
-
 		String packageName = packageElement.toString();
-		String injectorSimpleClassName = cl.getSimpleName().toString() + "Injector";
-		String injectorClassName = packageName + "." + injectorSimpleClassName;
 
-		MethodSpec stubOverride = MethodSpec.overriding(targetMethod)
-			.addStatement("throw new $T($S)", RuntimeException.class, "This is a stub and should not have been called")
-			.build();
+		//find injector(s) and target(s)
+		List<ExecutableElement> injectors = findAnnotatedMethods(cl, MultipleInjectors.class);
 
-		MethodSpec inject = MethodSpec.methodBuilder("inject")
-			.addModifiers(Modifier.PUBLIC)
-			.returns(void.class)
-			.addAnnotation(Override.class)
-			.addParameter(ParameterSpec.builder(
-				TypeName.get(processingEnv
-					.getElementUtils()
-					.getTypeElement("org.objectweb.asm.tree.ClassNode").asType()), "clazz").build())
-			.addParameter(ParameterSpec.builder(
-				TypeName.get(processingEnv
-					.getElementUtils()
-					.getTypeElement("org.objectweb.asm.tree.MethodNode").asType()), "main").build())
-			.addStatement("super." + injectorMethod.getSimpleName() + "(clazz, main)", TypeName.get(cl.asType()))
-			.build();
+		List<ExecutableElement> targets = findAnnotatedMethods(cl, Target.class);
 
-		TypeSpec injectorClass = TypeSpec.classBuilder(injectorSimpleClassName)
-			.addModifiers(Modifier.PUBLIC)
-			.superclass(cl.asType())
-			.addSuperinterface(ClassName.get(IInjector.class))
-			.addMethod(buildStringReturnMethod("name", cl.getSimpleName().toString()))
-			.addMethod(buildStringReturnMethod("reason", ann.reason()))
-			.addMethod(buildStringReturnMethod("targetClass", targetClassSrgName.replace('/', '.')))
-			.addMethod(buildStringReturnMethod("methodName", targetMethodSrgName))
-			.addMethod(buildStringReturnMethod("methodDesc", targetMethodDescriptor))
-			.addMethods(generateRequestedProxies(cl, mapper))
-			.addMethod(stubOverride)
-			.addMethod(inject)
-			.build();
+		//declare it once for efficiency
+		List<String> targetNames =
+			targets.stream()
+				.map(ExecutableElement::getSimpleName)
+				.map(Object::toString)
+				.collect(Collectors.toList());
 
-		JavaFile javaFile = JavaFile.builder(packageName, injectorClass).build();
+		//this will contain the classes to generate: the key is the class name
+		Map<String, InjectorInfo> toGenerate = new HashMap<>();
 
-		try {
-			JavaFileObject injectorFile = processingEnv.getFiler().createSourceFile(injectorClassName);
-			PrintWriter out = new PrintWriter(injectorFile.openWriter());
-			javaFile.writeTo(out);
-			out.close();
-		} catch(IOException e) {
-			throw new RuntimeException(e);
+		for(ExecutableElement inj : injectors) {
+			MultipleInjectors minjAnn = inj.getAnnotation(MultipleInjectors.class);
+			int iterationNumber = 1;
+			for(Injector injectorAnn : minjAnn.value()) { //java is dumb
+				List<ExecutableElement> injectionCandidates = targets;
+
+				//case 1: it has a name, try to match it
+				if(!injectorAnn.targetName().equals("") && targetNames.contains(injectorAnn.targetName()))
+					injectionCandidates =
+						injectionCandidates
+							.stream()
+							.filter(i -> i.getSimpleName().toString().equals(injectorAnn.targetName()))
+							.collect(Collectors.toList());
+
+				//case 2: try to match by injectTargetName
+				String inferredName = inj.getSimpleName()
+					.toString()
+					.replaceFirst("inject", "");
+				injectionCandidates =
+					injectionCandidates
+						.stream()
+						.filter(t -> t.getSimpleName().toString().equalsIgnoreCase(inferredName))
+						.collect(Collectors.toList());
+
+				//case 3: there is only one target
+				if(targets.size() == 1)
+					injectionCandidates.add(targets.get(0));
+
+				ExecutableElement injectionTarget = null;
+
+				if(injectionCandidates.size() == 1)
+					injectionTarget = injectionCandidates.get(0);
+
+				if(injectorAnn.params().length != 0) {
+					StringBuilder descr = new StringBuilder("(");
+					for(Class<?> p : injectorAnn.params())
+						descr.append(descriptorFromType(TypeName.get(p)));
+					descr.append(")");
+					injectionCandidates =
+						injectionCandidates
+							.stream()
+							.filter(t -> //we care about arguments but not really about return type
+									descr.toString()
+										.split("\\)")[0]
+										.equalsIgnoreCase(descriptorFromExecutableElement(t).split("\\)")[0])
+							).collect(Collectors.toList());
+				}
+
+				if(injectionCandidates.size() == 1)
+					injectionTarget = injectionCandidates.get(0);
+
+				//if we haven't found it yet, it's an ambiguity
+				if(injectionTarget == null)
+					throw new AmbiguousDefinitionException("Unclear target for injector " + inj.getSimpleName().toString() + "!");
+				else toGenerate.put(
+						cl.getSimpleName().toString() + "Injector" + iterationNumber,
+						new InjectorInfo(
+							inj, findRealMethod(
+								injectionTarget,
+								mapper
+							)
+						)
+					);
+				iterationNumber++;
+			}
 		}
 
-		this.generatedInjectors.add(injectorClassName);
+		//iterate over the map and generate the classes
+		for(String injName : toGenerate.keySet()) {
+			MethodSpec stubOverride = MethodSpec.overriding(toGenerate.get(injName).target)
+				.addStatement("throw new $T($S)", RuntimeException.class, "This is a stub and should not have been called")
+				.build();
+
+			MethodSpec inject = MethodSpec.methodBuilder("inject")
+				.addModifiers(Modifier.PUBLIC)
+				.returns(void.class)
+				.addAnnotation(Override.class)
+				.addParameter(ParameterSpec.builder(
+					TypeName.get(processingEnv
+						.getElementUtils()
+						.getTypeElement("org.objectweb.asm.tree.ClassNode").asType()), "clazz").build())
+				.addParameter(ParameterSpec.builder(
+					TypeName.get(processingEnv
+						.getElementUtils()
+						.getTypeElement("org.objectweb.asm.tree.MethodNode").asType()), "main").build())
+				.addStatement("super." + toGenerate.get(injName).injector.getSimpleName() + "(clazz, main)", TypeName.get(cl.asType()))
+				.build();
+
+			TypeSpec injectorClass = TypeSpec.classBuilder(injName)
+				.addModifiers(Modifier.PUBLIC)
+				.superclass(cl.asType())
+				.addSuperinterface(ClassName.get(IInjector.class))
+				.addMethod(buildStringReturnMethod("name", cl.getSimpleName().toString()))
+				.addMethod(buildStringReturnMethod("reason", patchAnn.reason()))
+				.addMethod(buildStringReturnMethod("targetClass", targetClassSrgName.replace('/', '.')))
+				.addMethod(buildStringReturnMethod("methodName", toGenerate.get(injName).target.getSimpleName().toString()))
+				.addMethod(buildStringReturnMethod("methodDesc", descriptorFromExecutableElement(toGenerate.get(injName).target)))
+				.addMethods(generateRequestedProxies(cl, mapper))
+				.addMethod(stubOverride)
+				.addMethod(inject)
+				.build();
+
+			JavaFile javaFile = JavaFile.builder(packageName, injectorClass).build();
+			String injectorClassName = packageName + "." + injName;
+
+			try {
+				JavaFileObject injectorFile = processingEnv.getFiler().createSourceFile(injectorClassName);
+				PrintWriter out = new PrintWriter(injectorFile.openWriter());
+				javaFile.writeTo(out);
+				out.close();
+			} catch(IOException e) {
+				throw new RuntimeException(e);
+			}
+
+			this.generatedInjectors.add(injectorClassName);
+		}
 	}
 
 	/**
@@ -220,64 +471,44 @@ public class LilleroProcessor extends AbstractProcessor {
 			.filter(m -> !m.getModifiers().contains(Modifier.STATIC)) //skip static stuff as we can't override it
 			.filter(m -> !m.getModifiers().contains(Modifier.FINAL)) //in case someone is trying to be funny
 			.forEach(m -> {
-				FindMethod ann = m.getAnnotation(FindMethod.class);
-				String targetMethodName = ann.name().equals("") ? m.getSimpleName().toString() : ann.name();
-				try {
-					MethodSpec.Builder b = MethodSpec.overriding(m);
-					Method targetMethod = ann.parent().getMethod(
-						targetMethodName,
-						ann.params()
-					);
-					b.addStatement("$T bd = $T.builder($S)",
-						MethodProxy.Builder.class,
-						MethodProxy.class,
-						targetMethodName
-					);
-					b.addStatement("bd.setParent($S)", targetMethod.getDeclaringClass().getCanonicalName());
-					b.addStatement("bd.setModifier($L)", targetMethod.getModifiers());
-					for(Class<?> p : targetMethod.getParameterTypes())
-						b.addStatement("bd.addParameter($T.class)", p);
-					b.addStatement("bd.setReturnType($T.class)", targetMethod.getReturnType());
-					b.addStatement("return bd.build()");
-					generated.add(b.build());
-				} catch(NoSuchMethodException e) {
-					processingEnv.getMessager().printMessage(
-						Diagnostic.Kind.ERROR,
-						"Method not found: " + targetMethodName
-					);
-				}
+				ExecutableElement targetMethod = findRealMethod(m, mapper);
+				MethodSpec.Builder b = MethodSpec.overriding(m);
+				b.addStatement("$T bd = $T.builder($S)",
+					MethodProxy.Builder.class,
+					MethodProxy.class,
+					m.getSimpleName().toString()
+				);
+				b.addStatement("bd.setParent($S)", ((TypeElement) targetMethod.getEnclosingElement()).getQualifiedName().toString());
+				for(Modifier mod : targetMethod.getModifiers())
+					b.addStatement("bd.addModifier($L)", mapModifier(mod));
+				for(TypeParameterElement p : targetMethod.getTypeParameters())
+					b.addStatement("bd.addParameter($T.class)", p.asType());
+				b.addStatement("bd.setReturnType($T.class)", targetMethod.getReturnType());
+				b.addStatement("return bd.build()");
+				generated.add(b.build());
 			});
 		findAnnotatedMethods(cl, FindField.class)
 			.stream()
 			.filter(m -> !m.getModifiers().contains(Modifier.STATIC))
 			.filter(m -> !m.getModifiers().contains(Modifier.FINAL))
 			.forEach(m -> {
-				FindField ann = m.getAnnotation(FindField.class);
-				String targetFieldName = ann.name().equals("") ? m.getSimpleName().toString() : ann.name();
-				try {
-					MethodSpec.Builder b = MethodSpec.overriding(m);
-					Field targetField = ann.parent().getField(targetFieldName);
-					b.addStatement("$T bd = $T.builder($S)",
-						FieldProxy.Builder.class,
-						FieldProxy.class,
-						targetFieldName
-					);
-					b.addStatement("bd.setParent($S)", targetField.getDeclaringClass().getCanonicalName());
-					b.addStatement("bd.setModifier($L)", targetField.getModifiers());
-					b.addStatement("bd.setType($T.class)", targetField.getType());
-					b.addStatement("return bd.build()");
-					generated.add(b.build());
-				} catch(NoSuchFieldException e) {
-					processingEnv.getMessager().printMessage(
-						Diagnostic.Kind.ERROR,
-						"Field not found: " + targetFieldName + " in class " + ann.parent().getCanonicalName()
-					);
-				}
+				VariableElement targetField = findField(m, mapper);
+				MethodSpec.Builder b = MethodSpec.overriding(m);
+				b.addStatement("$T bd = $T.builder($S)",
+					FieldProxy.Builder.class,
+					FieldProxy.class,
+					targetField.getSimpleName().toString()
+				);
+				b.addStatement("bd.setParent($S)", ((TypeElement) targetField.getEnclosingElement()).getQualifiedName().toString());
+				for(Modifier mod : targetField.getModifiers())
+					b.addStatement("bd.addModifier($L)", mapModifier(mod));
+				b.addStatement("bd.setType($T.class)", targetField.asType());
+				b.addStatement("return bd.build()");
+				generated.add(b.build());
 			});
 		return generated;
 	}
 
-
 	/**
 	 * Generates the Service Provider file for the generated injectors.
 	 */
@@ -294,4 +525,31 @@ public class LilleroProcessor extends AbstractProcessor {
 			throw new RuntimeException(e);
 		}
 	}
+
+	/**
+	 * Container for information about a class that is to be generated.
+	 * Only used internally.
+	 */
+	private static class InjectorInfo {
+		/**
+		 * The {@link ExecutableElement} corresponding to the injector method.
+		 */
+		public final ExecutableElement injector;
+
+
+		/**
+		 * The {@link ExecutableElement} corresponding to the target method.
+		 */
+		public final ExecutableElement target;
+
+		/**
+		 * Public constructor.
+		 * @param injector the injector {@link ExecutableElement}
+		 * @param target the target {@link ExecutableElement}
+		 */
+		public InjectorInfo(ExecutableElement injector, ExecutableElement target) {
+			this.injector = injector;
+			this.target = target;
+		}
+	}
 }
\ No newline at end of file