8308753: Class-File API transition to Preview

Reviewed-by: ihse, mchung, vromero

src/java.base/share/classes/java/lang/classfile/MethodSignature.java

@@ -0,0 +1,114 @@
+/*
+ * Copyright (c) 2022, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package java.lang.classfile;
+
+import java.lang.constant.MethodTypeDesc;
+import java.util.List;
+import jdk.internal.classfile.impl.SignaturesImpl;
+import static java.util.Objects.requireNonNull;
+import jdk.internal.classfile.impl.Util;
+import jdk.internal.javac.PreviewFeature;
+
+/**
+ * Models the generic signature of a method, as defined by {@jvms 4.7.9}.
+ *
+ * @since 22
+ */
+@PreviewFeature(feature = PreviewFeature.Feature.CLASSFILE_API)
+public sealed interface MethodSignature
+        permits SignaturesImpl.MethodSignatureImpl {
+
+    /** {@return the type parameters of this method} */
+    List<Signature.TypeParam> typeParameters();
+
+    /** {@return the signatures of the parameters of this method} */
+    List<Signature> arguments();
+
+    /** {@return the signatures of the return value of this method} */
+    Signature result();
+
+    /** {@return the signatures of the exceptions thrown by this method} */
+    List<Signature.ThrowableSig> throwableSignatures();
+
+    /** {@return the raw signature string} */
+    String signatureString();
+
+    /**
+     * {@return a method signature for a raw (no generic information) method descriptor}
+     * @param methodDescriptor the method descriptor
+     */
+    public static MethodSignature of(MethodTypeDesc methodDescriptor) {
+
+        requireNonNull(methodDescriptor);
+        return new SignaturesImpl.MethodSignatureImpl(
+                List.of(),
+                List.of(),
+                Signature.of(methodDescriptor.returnType()),
+                Util.mappedList(methodDescriptor.parameterList(), Signature::of));
+    }
+
+    /**
+     * {@return a method signature}
+     * @param result signature for the return type
+     * @param arguments signatures for the method arguments
+     */
+    public static MethodSignature of(Signature result,
+                                     Signature... arguments) {
+
+        return new SignaturesImpl.MethodSignatureImpl(List.of(),
+                                                      List.of(),
+                                                      requireNonNull(result),
+                                                      List.of(arguments));
+    }
+
+    /**
+     * {@return a method signature}
+     * @param typeParameters signatures for the type parameters
+     * @param exceptions signatures for the exceptions
+     * @param result signature for the return type
+     * @param arguments signatures for the method arguments
+     */
+    public static MethodSignature of(List<Signature.TypeParam> typeParameters,
+                                     List<Signature.ThrowableSig> exceptions,
+                                     Signature result,
+                                     Signature... arguments) {
+
+        return new SignaturesImpl.MethodSignatureImpl(
+                List.copyOf(requireNonNull(typeParameters)),
+                List.copyOf(requireNonNull(exceptions)),
+                requireNonNull(result),
+                List.of(arguments));
+    }
+
+    /**
+     * Parses a raw method signature string into a {@linkplain MethodSignature}
+     * @param methodSignature the raw method signature string
+     * @return method signature
+     */
+    public static MethodSignature parseFrom(String methodSignature) {
+
+        return new SignaturesImpl().parseMethodSignature(requireNonNull(methodSignature));
+    }
+}