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)

11 files changed, 708 insertions, 130 deletions

diff --git a/src/main/java/ftbsc/lll/exceptions/AmbiguousDefinitionException.java b/src/main/java/ftbsc/lll/exceptions/AmbiguousDefinitionException.java
new file mode 100644
index 0000000..1befaa8
--- /dev/null
+++ b/src/main/java/ftbsc/lll/exceptions/AmbiguousDefinitionException.java
@@ -0,0 +1,25 @@
+package ftbsc.lll.exceptions;
+
+/**
+ * Thrown when the processor finds multiple methods matching the
+ * given criteria.
+ */
+public class AmbiguousDefinitionException extends RuntimeException {
+
+	/**
+	 * Constructs a new ambiguous definition exception with the specified detail message.
+	 * @param message the detail message
+	 */
+	public AmbiguousDefinitionException(String message) {
+		super(message);
+	}
+
+	/**
+	 * Constructs a new ambiguous definition exception with the specified detail message and cause.
+	 * @param  message the detail message
+	 * @param  cause the cause, may be null (indicating nonexistent or unknown cause)
+	 */
+	public AmbiguousDefinitionException(String message, Throwable cause) {
+		super(message, cause);
+	}
+}
diff --git a/src/main/java/ftbsc/lll/exceptions/MappingNotFoundException.java b/src/main/java/ftbsc/lll/exceptions/MappingNotFoundException.java
new file mode 100644
index 0000000..817761b
--- /dev/null
+++ b/src/main/java/ftbsc/lll/exceptions/MappingNotFoundException.java
@@ -0,0 +1,17 @@
+package ftbsc.lll.exceptions;
+
+import ftbsc.lll.processor.tools.SrgMapper;
+
+/**
+ * Thrown upon failure to find the requested mapping within a loaded {@link SrgMapper}.
+ */
+public class MappingNotFoundException extends RuntimeException {
+
+	/**
+	 * Constructs a new mapping not found exception for the specified mapping.
+	 * @param mapping the detail message
+	 */
+	public MappingNotFoundException(String mapping) {
+		super("Could not find mapping for " + mapping + "!");
+	}
+}
diff --git a/src/main/java/ftbsc/lll/exceptions/TargetNotFoundException.java b/src/main/java/ftbsc/lll/exceptions/TargetNotFoundException.java
new file mode 100644
index 0000000..5be3d77
--- /dev/null
+++ b/src/main/java/ftbsc/lll/exceptions/TargetNotFoundException.java
@@ -0,0 +1,15 @@
+package ftbsc.lll.exceptions;
+
+/**
+ * Thrown upon failure to find an existing method from a stub.
+ */
+public class TargetNotFoundException extends RuntimeException {
+
+	/**
+	 * Constructs a new target not found exception for the specified method stub.
+	 * @param stub the stub's name (and descriptor possibly)
+	 */
+	public TargetNotFoundException(String stub) {
+		super("Could not find member corresponding to stub: " + stub);
+	}
+}
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
diff --git a/src/main/java/ftbsc/lll/processor/annotations/FindField.java b/src/main/java/ftbsc/lll/processor/annotations/FindField.java
index 9b5a824..c13fd46 100644
--- a/src/main/java/ftbsc/lll/processor/annotations/FindField.java
+++ b/src/main/java/ftbsc/lll/processor/annotations/FindField.java
@@ -16,6 +16,6 @@ import java.lang.annotation.RetentionPolicy;
 @Retention(RetentionPolicy.CLASS)
 @java.lang.annotation.Target(ElementType.METHOD)
 public @interface FindField {
-	Class<?> parent();
+	Class<?> parent() default Object.class;
 	String name() default "";
 }
diff --git a/src/main/java/ftbsc/lll/processor/annotations/FindMethod.java b/src/main/java/ftbsc/lll/processor/annotations/FindMethod.java
index bf93442..76fe560 100644
--- a/src/main/java/ftbsc/lll/processor/annotations/FindMethod.java
+++ b/src/main/java/ftbsc/lll/processor/annotations/FindMethod.java
@@ -17,7 +17,7 @@ import java.lang.annotation.RetentionPolicy;
 @Retention(RetentionPolicy.CLASS)
 @java.lang.annotation.Target(ElementType.METHOD)
 public @interface FindMethod {
-	Class<?> parent();
+	Class<?> parent() default Object.class;
 	String name() default "";
-	Class<?>[] params();
+	Class<?>[] params() default {};
 }
diff --git a/src/main/java/ftbsc/lll/processor/annotations/Injector.java b/src/main/java/ftbsc/lll/processor/annotations/Injector.java
index f5e22aa..c26f704 100644
--- a/src/main/java/ftbsc/lll/processor/annotations/Injector.java
+++ b/src/main/java/ftbsc/lll/processor/annotations/Injector.java
@@ -1,6 +1,7 @@
 package ftbsc.lll.processor.annotations;
 
 import java.lang.annotation.ElementType;
+import java.lang.annotation.Repeatable;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 
@@ -14,5 +15,9 @@ import java.lang.annotation.RetentionPolicy;
  * @see Target
  */
 @Retention(RetentionPolicy.CLASS)
+@Repeatable(MultipleInjectors.class)
 @java.lang.annotation.Target(ElementType.METHOD)
-public @interface Injector {}
+public @interface Injector {
+	String targetName() default "";
+	Class<?>[] params() default {};
+}
diff --git a/src/main/java/ftbsc/lll/processor/annotations/MultipleInjectors.java b/src/main/java/ftbsc/lll/processor/annotations/MultipleInjectors.java
new file mode 100644
index 0000000..5c6382e
--- /dev/null
+++ b/src/main/java/ftbsc/lll/processor/annotations/MultipleInjectors.java
@@ -0,0 +1,11 @@
+package ftbsc.lll.processor.annotations;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+
+@Retention(RetentionPolicy.CLASS)
+@java.lang.annotation.Target(ElementType.METHOD)
+public @interface MultipleInjectors {
+	Injector[] value();
+}
diff --git a/src/main/java/ftbsc/lll/processor/annotations/Target.java b/src/main/java/ftbsc/lll/processor/annotations/Target.java
index 885bd9c..38477d1 100644
--- a/src/main/java/ftbsc/lll/processor/annotations/Target.java
+++ b/src/main/java/ftbsc/lll/processor/annotations/Target.java
@@ -15,4 +15,15 @@ import java.lang.annotation.RetentionPolicy;
  */
 @Retention(RetentionPolicy.CLASS)
 @java.lang.annotation.Target(ElementType.METHOD)
-public @interface Target {}
+public @interface Target {
+
+	/**
+	 * When set to false, tells the processor to first try to match a single method by name,
+	 * and to only check parameters if further clarification is needed.
+	 * @implNote While non-strict mode is more computationally efficient, it's ultimately not
+	 *           relevant, as it only matters at compile time. Do not set this to true unless
+	 *           you are sure know what you're doing.
+	 * @since 0.3.0
+	 */
+	boolean strict() default true;
+}
diff --git a/src/main/java/ftbsc/lll/processor/ASTUtils.java b/src/main/java/ftbsc/lll/processor/tools/ASTUtils.java
index eba5d89..c35e008 100644
--- a/src/main/java/ftbsc/lll/processor/ASTUtils.java
+++ b/src/main/java/ftbsc/lll/processor/tools/ASTUtils.java
@@ -1,4 +1,4 @@
-package ftbsc.lll.processor;
+package ftbsc.lll.processor.tools;
 
 import com.squareup.javapoet.ArrayTypeName;
 import com.squareup.javapoet.ClassName;
@@ -9,6 +9,7 @@ import ftbsc.lll.tools.DescriptorBuilder;
 import javax.lang.model.element.ExecutableElement;
 import javax.lang.model.element.Modifier;
 import javax.lang.model.element.TypeElement;
+import javax.lang.model.type.MirroredTypeException;
 import javax.lang.model.type.TypeMirror;
 import java.lang.annotation.Annotation;
 import java.util.List;
@@ -35,12 +36,11 @@ public class ASTUtils {
 	}
 
 	/**
-	 * Builds a type descriptor from the given {@link TypeMirror}
-	 * @param t the {@link TypeMirror} representing the desired type
+	 * Builds a type descriptor from the given {@link TypeName}.
+	 * @param type the {@link TypeName} representing the desired type
 	 * @return a {@link String} containing the relevant descriptor
 	 */
-	public static String descriptorFromType(TypeMirror t) {
-		TypeName type = TypeName.get(t);
+	public static String descriptorFromType(TypeName type) {
 		StringBuilder desc = new StringBuilder();
 		//add array brackets
 		while(type instanceof ArrayTypeName) {
@@ -74,6 +74,15 @@ public class ASTUtils {
 	}
 
 	/**
+	 * Builds a type descriptor from the given {@link TypeMirror}.
+	 * @param t the {@link TypeMirror} representing the desired type
+	 * @return a {@link String} containing the relevant descriptor
+	 */
+	public static String descriptorFromType(TypeMirror t) {
+		return descriptorFromType(TypeName.get(t));
+	}
+
+	/**
 	 * Builds a method descriptor from the given {@link ExecutableElement}.
 	 * @param m the {@link ExecutableElement} for the method
 	 * @return a {@link String} containing the relevant descriptor
@@ -123,4 +132,20 @@ public class ASTUtils {
 				return 0;
 		}
 	}
+
+	/**
+	 * Safely converts a {@link Class} to its fully qualified name. See
+	 * <a href="https://area-51.blog/2009/02/13/getting-class-values-from-annotations-in-an-annotationprocessor">this blogpost</a>
+	 * for more information.
+	 * @param clazz the class to get the name for
+	 * @return the fully qualified name of the given class
+	 * @since 0.3.0
+	 */
+	public static String getClassFullyQualifiedName(Class<?> clazz) {
+		try {
+			return clazz.getCanonicalName();
+		} catch(MirroredTypeException e) {
+			return e.getTypeMirror().toString();
+		}
+	}
 }
diff --git a/src/main/java/ftbsc/lll/processor/tools/SrgMapper.java b/src/main/java/ftbsc/lll/processor/tools/SrgMapper.java
new file mode 100644
index 0000000..d3c9f79
--- /dev/null
+++ b/src/main/java/ftbsc/lll/processor/tools/SrgMapper.java
@@ -0,0 +1,211 @@
+package ftbsc.lll.processor.tools;
+
+import ftbsc.lll.exceptions.MappingNotFoundException;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.concurrent.atomic.AtomicReference;
+import java.util.stream.Stream;
+
+/**
+ * Parses a .tsrg file into a mapper capable of converting from
+ * deobfuscated names to SRG names.
+ * Obviously, it may only be used at runtime if the .tsrg file is
+ * included in the resources. However, in that case, I'd recommend
+ * using the built-in Forge one and refrain from including an extra
+ * resource for no good reason.
+ * @since 0.2.0
+ */
+public class SrgMapper {
+
+	/**
+	 * A Map using the deobfuscated names as keys,
+	 * holding information for that Srg class as value.
+	 */
+	private final Map<String, ObfuscationData> mapper = new HashMap<>();
+
+	/**
+	 * The public constructor.
+	 * Should be passed a {@link Stream} of Strings, one representing each line.
+	 * Whether they contain line endings or not is irrelevant.
+	 * @param str a {@link Stream} of strings
+	 */
+	public SrgMapper(Stream<String> str) {
+		AtomicReference<String> currentClass = new AtomicReference<>("");
+		str.forEach(l -> {
+			if(l.startsWith("\t"))
+				mapper.get(currentClass.get()).addMember(l);
+			else {
+				ObfuscationData s = new ObfuscationData(l);
+				currentClass.set(s.mcpName);
+				mapper.put(s.mcpName, s);
+			}
+		});
+	}
+
+	/**
+	 * Gets the SRG-obfuscated name of the class.
+	 * @param mcp the MCP (deobfuscated) internal name of the desired class
+	 * @return the SRG name of the class
+	 * @throws MappingNotFoundException if no mapping is found
+	 */
+	public String getSrgClass(String mcp)  {
+		ObfuscationData data = mapper.get(mcp);
+		if(data == null)
+			throw new MappingNotFoundException(mcp);
+		else return data.srgName;
+	}
+
+	/**
+	 * Gets the MCP (deobfuscated) name of the class.
+	 * Due to how it's implemented, it's considerably less efficient than its
+	 * opposite operation.
+	 * @param srg the SRG-obfuscated internal name of the desired class
+	 * @return the MCP name of the class
+	 */
+	public String getMcpClass(String srg) {
+		ObfuscationData data = getObfuscationData(srg);
+		return data.mcpName;
+	}
+
+	/**
+	 * Gets one between the SRG and MCP names.
+	 * @param name the internal name of the desired class in either format
+	 * @param obf whether it should return the obfuscated name
+	 * @return a {@link String} containing the internal name of the class
+	 * @throws MappingNotFoundException if no mapping is found
+	 * @since 0.3.0
+	 */
+	public String mapClass(String name, boolean obf) {
+		String srg;
+		try {
+			srg = this.getSrgClass(name);
+		} catch(MappingNotFoundException e) {
+			srg = name;
+			name = this.getMcpClass(srg);
+		}
+		if(obf) return srg;
+		else return name;
+	}
+
+	/**
+	 * Gets the SRG-obfuscated name of a class member (field or method).
+	 * The method signature must be in this format: "methodName methodDescriptor",
+	 * with a space, because that's how it is in .tsrg files.
+	 * @param mcpClass the MCP (deobfuscated) internal name of the container class
+	 * @param member the field name or method signature
+	 * @return the SRG name of the given member
+	 * @throws MappingNotFoundException if no mapping is found
+	 */
+	public String getSrgMember(String mcpClass, String member) {
+		ObfuscationData data = mapper.get(mcpClass);
+		if(data == null)
+			throw new MappingNotFoundException(mcpClass + "::" + member);
+		return data.members.get(member);
+	}
+
+	/**
+	 * Gets the MCP (deobfuscated) name of the given member.
+	 * Due to how it's implemented, it's considerably less efficient than its
+	 * opposite operation.
+	 * @param srgClass the SRG-obfuscated internal name of the container class
+	 * @param member the field name or method signature
+	 * @return the MCP name of the given member
+	 */
+	public String getMcpMember(String srgClass, String member) {
+		ObfuscationData data = getObfuscationData(srgClass);
+		for(String mcp : data.members.keySet())
+			if(data.members.get(mcp).equals(member))
+				return mcp;
+		return null;
+	}
+
+	/**
+	 * Obfuscates or deobfuscates a member, given one of its names and the effective.
+	 * @param className the internal or fully qualified name of the container class
+	 * @param memberName the member of the class
+	 * @param obf whether it should return the obfuscated name
+	 * @return the mapped member name
+	 * @throws MappingNotFoundException if no mapping is found
+	 * @since 0.3.0
+	 */
+	public String mapMember(String className, String memberName, boolean obf) {
+		className = className.replace('.', '/');
+		String effectiveClassName = this.mapClass(className, obf);
+		String srgMemberName;
+		try {
+			srgMemberName = this.getSrgMember(effectiveClassName, memberName);
+		} catch(MappingNotFoundException e) {
+			srgMemberName = memberName;
+			memberName = this.getMcpMember(effectiveClassName, memberName);
+		}
+		if(obf) return srgMemberName;
+		else return memberName;
+	}
+
+	/**
+	 * Used internally. Gets the obfuscation data corresponding to the given SRG name.
+	 * @return the desired {@link ObfuscationData} object
+	 * @throws MappingNotFoundException if no {@link ObfuscationData} object is found
+	 */
+	private ObfuscationData getObfuscationData(String srg) {
+		for(ObfuscationData s : mapper.values())
+			if(s.srgName.equals(srg))
+				return s;
+		throw new MappingNotFoundException(srg);
+	}
+
+	/**
+	 * Private class used internally for storing information about each
+	 * class. It's private because there is no good reason anyone would
+	 * want to access this outside of this class.
+	 */
+	private static class ObfuscationData {
+		/**
+		 * The MCP internal name (FQN with '/' instad of '.') of the class.
+		 */
+		private final String mcpName;
+
+		/**
+		 * The SRG internal name (FQN with '/' instad of '.') of the class.
+		 */
+		private final String srgName;
+
+		/**
+		 * A {@link Map} tying each member's deobfuscated name or signature to its
+		 * SRG name.
+		 */
+		private final Map<String, String> members;
+
+
+		/**
+		 * The constructor. It takes in the line where the class is declared,
+		 * which looks something like this:
+		 * {@code internal/name/mcp internal/name/srg }
+		 * @param s the String represeting the declaration line
+		 */
+		private ObfuscationData(String s) {
+			String[] split = s.trim().split(" ");
+			this.mcpName = split[0];
+			this.srgName = split[1];
+			this.members = new HashMap<>();
+		}
+
+		/**
+		 * Adds a member to the target class. It takes in the line where the
+		 * member is declared.
+		 * For fields it looks like this:
+		 * {@code fieldMcpName field_srg_name}
+		 * For methods it looks like this:
+		 * {@code methodName methodDescriptor method_srg_name}
+		 * @param s the String representing the declaration line
+		 */
+		public void addMember(String s) {
+			String[] split = s.trim().split(" ");
+			if(split.length == 2) //field
+				members.put(split[0], split[1]);
+			else if (split.length == 3) //method
+				members.put(split[0] + " " + split[1], split[2]);
+		}
+	}
+}