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+package ftbsc.lll.processor.utils;
+
+import ftbsc.lll.exceptions.AmbiguousDefinitionException;
+import ftbsc.lll.exceptions.MappingNotFoundException;
+import ftbsc.lll.exceptions.NotAProxyException;
+import ftbsc.lll.exceptions.TargetNotFoundException;
+import ftbsc.lll.mapper.tools.Mapper;
+import ftbsc.lll.mapper.tools.data.ClassData;
+import ftbsc.lll.mapper.tools.data.FieldData;
+import ftbsc.lll.mapper.tools.data.MethodData;
+import ftbsc.lll.processor.annotations.Target;
+import ftbsc.lll.processor.containers.ClassContainer;
+import ftbsc.lll.proxies.ProxyType;
+
+import javax.annotation.processing.ProcessingEnvironment;
+import javax.lang.model.element.*;
+import javax.lang.model.type.*;
+import java.lang.annotation.Annotation;
+import java.util.Collection;
+import java.util.List;
+import java.util.function.Function;
+import java.util.stream.Collectors;
+
+/**
+ * Collection of AST-related static utils that didn't really fit into the main class.
+ */
+public class ASTUtils {
+ /**
+ * Finds, among the methods of a class cl, the one annotated with ann, and tries to build
+ * an {@link Element} from it.
+ * @param parent the parent {@link Element} to the desired element
+ * @param ann the {@link Class} corresponding to the desired annotation
+ * @param <T> the type of {@link Element} to use
+ * @return a {@link List} of {@link Element}s annotated with the given annotation
+ * @since 0.2.0
+ */
+ @SuppressWarnings("unchecked")
+ public static <T extends Element> List<T> findAnnotatedElement(Element parent, Class<? extends Annotation> ann) {
+ return parent.getEnclosedElements()
+ .stream()
+ .filter(e -> e.getAnnotationsByType(ann).length != 0)
+ .map(e -> (T) e)
+ .collect(Collectors.toList());
+ }
+
+ /**
+ * Maps a {@link javax.lang.model.element.Modifier} to its reflective
+ * {@link java.lang.reflect.Modifier} equivalent.
+ * @param m the {@link Modifier} to map
+ * @return an integer representing the modifier
+ * @see java.lang.reflect.Modifier
+ * @since 0.2.0
+ */
+ public static int mapModifier(Modifier m) {
+ switch(m) {
+ case PUBLIC:
+ return java.lang.reflect.Modifier.PUBLIC;
+ case PROTECTED:
+ return java.lang.reflect.Modifier.PROTECTED;
+ case PRIVATE:
+ return java.lang.reflect.Modifier.PRIVATE;
+ case ABSTRACT:
+ return java.lang.reflect.Modifier.ABSTRACT;
+ case STATIC:
+ return java.lang.reflect.Modifier.STATIC;
+ case FINAL:
+ return java.lang.reflect.Modifier.FINAL;
+ case TRANSIENT:
+ return java.lang.reflect.Modifier.TRANSIENT;
+ case VOLATILE:
+ return java.lang.reflect.Modifier.VOLATILE;
+ case SYNCHRONIZED:
+ return java.lang.reflect.Modifier.SYNCHRONIZED;
+ case NATIVE:
+ return java.lang.reflect.Modifier.NATIVE;
+ case STRICTFP:
+ return java.lang.reflect.Modifier.STRICT;
+ default:
+ return 0;
+ }
+ }
+
+ /**
+ * Takes in a {@link Collection} of AST {@link Modifier}s and
+ * returns them mapped to their reflective integer equivalent.
+ * @param modifiers the {@link Modifier}s
+ * @return an integer value representing them
+ * @since 0.5.0
+ */
+ public static int mapModifiers(Collection<Modifier> modifiers) {
+ int i = 0;
+ for(Modifier m : modifiers)
+ i |= mapModifier(m);
+ return i;
+ }
+
+ /**
+ * Safely extracts a {@link Class} from an annotation and gets a {@link TypeMirror} representing it.
+ * @param ann the annotation containing the class
+ * @param classFunction the annotation function returning the class
+ * @param env the {@link ProcessingEnvironment} to perform the operation in
+ * @param <T> the type of the annotation carrying the information
+ * @return a {@link TypeMirror} representing the requested {@link Class}
+ * @since 0.3.0
+ */
+ public static <T extends Annotation> TypeMirror getTypeFromAnnotation(
+ T ann, Function<T, Class<?>> classFunction, ProcessingEnvironment env) {
+ try {
+ String fqn = classFunction.apply(ann).getCanonicalName();
+ if(fqn == null)
+ fqn = "";
+ return env.getElementUtils().getTypeElement(fqn).asType();
+ } catch(MirroredTypeException e) {
+ return e.getTypeMirror();
+ }
+ }
+
+ /**
+ * Gets the internal name from an {@link TypeMirror}.
+ * @param type the {@link TypeMirror} in question
+ * @param env the {@link ProcessingEnvironment} to perform the operation in
+ * @return the internal name at compile time, or null if it wasn't a qualifiable
+ * @since 0.5.1
+ */
+ public static String internalNameFromType(TypeMirror type, ProcessingEnvironment env) {
+ //needed to actually turn elem into a TypeVariable, find it ignoring generics
+ Element elem = env.getTypeUtils().asElement(env.getTypeUtils().erasure(type));
+ StringBuilder fqnBuilder = new StringBuilder();
+ while(elem.getEnclosingElement() != null && elem.getEnclosingElement().getKind() != ElementKind.PACKAGE) {
+ fqnBuilder
+ .insert(0, elem.getSimpleName().toString())
+ .insert(0, "$");
+ elem = elem.getEnclosingElement();
+ }
+ return fqnBuilder
+ .insert(0, env.getTypeUtils().erasure(elem.asType()).toString())
+ .toString()
+ .replace('.', '/');
+ }
+
+ /**
+ * Builds a type descriptor from the given {@link TypeMirror}.
+ * @param t the {@link TypeMirror} representing the desired type
+ * @param env the {@link ProcessingEnvironment} to perform the operation in
+ * @return a {@link String} containing the relevant descriptor
+ */
+ public static String descriptorFromType(TypeMirror t, ProcessingEnvironment env) {
+ t = env.getTypeUtils().erasure(t); //type erasure
+
+ StringBuilder desc = new StringBuilder();
+ //add array brackets
+ while(t.getKind() == TypeKind.ARRAY) {
+ desc.append("[");
+ t = ((ArrayType) t).getComponentType();
+ }
+
+ if(t.getKind() == TypeKind.TYPEVAR)
+ t = ((TypeVariable) t).getUpperBound();
+
+ if(t.getKind() == TypeKind.DECLARED)
+ desc
+ .append("L")
+ .append(internalNameFromType(t, env))
+ .append(";");
+ else {
+ switch(t.getKind()) {
+ case BOOLEAN:
+ desc.append("Z");
+ break;
+ case CHAR:
+ desc.append("C");
+ break;
+ case BYTE:
+ desc.append("B");
+ break;
+ case SHORT:
+ desc.append("S");
+ break;
+ case INT:
+ desc.append("I");
+ break;
+ case FLOAT:
+ desc.append("F");
+ break;
+ case LONG:
+ desc.append("J");
+ break;
+ case DOUBLE:
+ desc.append("D");
+ break;
+ case VOID:
+ desc.append("V");
+ break;
+ }
+ }
+
+ return desc.toString();
+ }
+
+ /**
+ * Builds a method descriptor from the given {@link ExecutableElement}.
+ * @param m the {@link ExecutableElement} for the method
+ * @param env the {@link ProcessingEnvironment} to perform the operation in
+ * @return a {@link String} containing the relevant descriptor
+ */
+ public static String descriptorFromExecutableElement(ExecutableElement m, ProcessingEnvironment env) {
+ StringBuilder methodSignature = new StringBuilder();
+ methodSignature.append("(");
+ m.getParameters().forEach(p -> methodSignature.append(descriptorFromType(p.asType(), env)));
+ methodSignature.append(")");
+ methodSignature.append(descriptorFromType(m.getReturnType(), env));
+ return methodSignature.toString();
+ }
+
+ /**
+ * Gets the {@link ClassData} corresponding to the given fully-qualified name,
+ * or creates a false one with the same, non-obfuscated name twice.
+ * @param name the internal name of the class to convert
+ * @param mapper the {@link Mapper} to use, may be null
+ * @return the fully qualified class name
+ * @since 0.6.1
+ */
+ public static ClassData getClassData(String name, Mapper mapper) {
+ try {
+ name = name.replace('.', '/'); //just in case
+ if(mapper != null)
+ return mapper.getClassData(name);
+ } catch(MappingNotFoundException ignored) {}
+ return new ClassData(name, name);
+ }
+
+ /**
+ * Gets the {@link MethodData} corresponding to the method matching the given
+ * name, parent and descriptor, or creates a dummy one with fake data if no
+ * valid mapping is found.
+ * @param parent the internal name of the parent class
+ * @param name the name of the member
+ * @param descriptor the descriptor of the method
+ * @param mapper the {@link Mapper} to use, may be null
+ * @return the fully qualified class name
+ * @since 0.6.1
+ */
+ public static MethodData getMethodData(String parent, String name, String descriptor, Mapper mapper) {
+ try {
+ name = name.replace('.', '/'); //just in case
+ if(mapper != null)
+ return mapper.getMethodData(parent, name, descriptor);
+ } catch(MappingNotFoundException ignored) {}
+ return new MethodData(getClassData(name, mapper), name, name, descriptor);
+ }
+
+ /**
+ * Gets the {@link FieldData} corresponding to the field matching the given
+ * name and parent, or creates a dummy one with fake data if no valid
+ * mapping is found.
+ * @param parent the internal name of the parent class
+ * @param name the name of the member
+ * @param mapper the {@link Mapper} to use, may be null
+ * @return the fully qualified class name
+ * @since 0.6.1
+ */
+ public static FieldData getFieldData(String parent, String name, Mapper mapper) {
+ try {
+ name = name.replace('.', '/'); //just in case
+ if(mapper != null)
+ return mapper.getFieldData(parent, name);
+ } catch(MappingNotFoundException ignored) {}
+ return new FieldData(getClassData(name, mapper), name, name);
+ }
+
+ /**
+ * Finds a member given the name, the container class and (if it's a method) the descriptor.
+ * @param parent the {@link ClassContainer} representing the parent
+ * @param name the name to search for
+ * @param descr the descriptor to search for, or null if it's not a method
+ * @param strict whether to perform lookup in strict mode (see {@link Target#strict()} for more information)
+ * @param field whether the member being searched is a field
+ * @param env the {@link ProcessingEnvironment} to perform the operation in
+ * @return the desired member, if it exists
+ * @throws AmbiguousDefinitionException if it finds more than one candidate
+ * @throws TargetNotFoundException if it finds no valid candidate
+ * @since 0.3.0
+ */
+ public static Element findMember(
+ ClassContainer parent, String name, String descr,
+ boolean strict, boolean field, ProcessingEnvironment env) {
+ if(parent.elem == null)
+ throw new TargetNotFoundException("parent class", parent.data.name);
+ //try to find by name
+ List<Element> candidates = parent.elem.getEnclosedElements()
+ .stream()
+ .filter(e -> (field && e instanceof VariableElement) || e instanceof ExecutableElement)
+ .filter(e -> e.getSimpleName().contentEquals(name))
+ .collect(Collectors.toList());
+
+ if(candidates.isEmpty())
+ throw new TargetNotFoundException(field ? "field" : "method", name, parent.data.name);
+
+ if(candidates.size() == 1 && (!strict || descr == null))
+ return candidates.get(0);
+
+ if(descr == null) {
+ throw new AmbiguousDefinitionException(String.format(
+ "Found %d members named %s in class %s!", candidates.size(), name, parent.data.name));
+ } else {
+ if(field) {
+ //fields can verify the signature for extra safety
+ //but there can only be 1 field with a given name
+ if(!descriptorFromType(candidates.get(0).asType(), env).equals(descr))
+ throw new TargetNotFoundException("field", String.format(
+ "%s with descriptor %s", name, descr), parent.data.name);
+ } else {
+ candidates = candidates.stream()
+ .map(e -> (ExecutableElement) e)
+ .filter(strict
+ ? c -> descr.equals(descriptorFromExecutableElement(c, env))
+ : c -> descr.split("\\)")[0].equalsIgnoreCase(
+ descriptorFromExecutableElement(c, env).split("\\)")[0])
+ ).collect(Collectors.toList());
+ }
+ if(candidates.isEmpty())
+ throw new TargetNotFoundException("method", String.format(
+ "%s %s", name, descr), parent.data.name);
+ if(candidates.size() > 1)
+ throw new AmbiguousDefinitionException(String.format(
+ "Found %d methods named %s in class %s!", candidates.size(), name, parent.data.name));
+ return candidates.get(0);
+ }
+ }
+
+ /**
+ * Tries to find the method being overloaded by the given {@link ExecutableElement}.
+ * In case of multiple layers of overloading, it finds the original one. In case of
+ * no overloading, it returns the given method.
+ * @param context the {@link TypeElement} representing the parent class
+ * @param method an {@link ExecutableElement} representing the overloading method
+ * @param env the {@link ProcessingEnvironment} to perform the operation in
+ * @return the original overloaded method, or the given method if it was not found
+ * @since 0.5.2
+ */
+ public static ExecutableElement findOverloadedMethod(
+ TypeElement context, ExecutableElement method, ProcessingEnvironment env) {
+ if (context.getSuperclass().getKind() == TypeKind.NONE)
+ return method;
+
+ for (Element elem : context.getEnclosedElements()) {
+ if (elem.getKind() != ElementKind.METHOD)
+ continue;
+ if (env.getElementUtils().overrides(method, (ExecutableElement) elem, context)) {
+ method = (ExecutableElement) elem;
+ break; //found
+ }
+ }
+
+ return findOverloadedMethod(
+ (TypeElement) env.getTypeUtils().asElement(context.getSuperclass()),
+ method, env
+ );
+ }
+
+ /**
+ * Tries to find the "synthetic bridge" generated by the compiler for a certain overridden
+ * method. A "bridge" only exists in cases where type erasure is involved (i.e. when the
+ * method being overridden uses a generic parameter that is not preserved in the overriding
+ * method).
+ * @param context the {@link TypeElement} representing the parent class
+ * @param method an {@link ExecutableElement} stub representing the overloading method
+ * @param env the {@link ProcessingEnvironment} to perform the operation in
+ * @return the "bridge"
+ * @throws TargetNotFoundException if the method in question was not overriding anything, or
+ * if the method it was overriding does not require a bridge
+ * @since 0.5.2
+ */
+ public static ExecutableElement findSyntheticBridge(
+ TypeElement context, ExecutableElement method, ProcessingEnvironment env) throws TargetNotFoundException {
+ ExecutableElement overridding = findOverloadedMethod(context, method, env);
+ if(descriptorFromExecutableElement(overridding, env).equals(descriptorFromExecutableElement(method, env)))
+ throw new TargetNotFoundException(
+ "bridge method for",
+ overridding.getSimpleName().toString(),
+ context.getQualifiedName().toString()
+ );
+ else return overridding;
+ }
+
+ /**
+ * Utility method for finding out what type of proxy a field is.
+ * It will fail if the return type is not a known type of proxy.
+ * @param v the annotated {@link VariableElement}
+ * @return the {@link ProxyType} for the element
+ * @throws NotAProxyException if it's neither
+ * @since 0.4.0
+ */
+ public static ProxyType getProxyType(VariableElement v) {
+ String returnTypeFQN = v.asType().toString();
+ switch(returnTypeFQN) {
+ case "ftbsc.lll.proxies.impl.FieldProxy":
+ return ProxyType.FIELD;
+ case "ftbsc.lll.proxies.impl.MethodProxy":
+ return ProxyType.METHOD;
+ case "ftbsc.lll.proxies.impl.TypeProxy":
+ return ProxyType.TYPE;
+ case "ftbsc.lll.proxies.impl.PackageProxy":
+ return ProxyType.PACKAGE;
+ default:
+ throw new NotAProxyException(v.getEnclosingElement().getSimpleName().toString(), v.getSimpleName().toString());
+ }
+ }
+}