8294982: Implementation of Classfile API

Reviewed-by: ihse, psandoz, mcimadamore

src/java.base/share/classes/jdk/internal/classfile/attribute/StackMapFrameInfo.java

@@ -0,0 +1,122 @@
+/*
+ * Copyright (c) 2023, 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 jdk.internal.classfile.attribute;
+
+import java.lang.constant.ClassDesc;
+import java.util.List;
+
+import jdk.internal.classfile.Label;
+import jdk.internal.classfile.constantpool.ClassEntry;
+import jdk.internal.classfile.impl.StackMapDecoder;
+import jdk.internal.classfile.impl.TemporaryConstantPool;
+import static jdk.internal.classfile.Classfile.*;
+
+/**
+ * Models stack map frame of {@code StackMapTable} attribute {@jvms 4.7.4}.
+ */
+public sealed interface StackMapFrameInfo
+            permits StackMapDecoder.StackMapFrameImpl {
+
+    int frameType();
+    Label target();
+    List<VerificationTypeInfo> locals();
+    List<VerificationTypeInfo> stack();
+
+    public static StackMapFrameInfo of(Label target,
+            List<VerificationTypeInfo> locals,
+            List<VerificationTypeInfo> stack) {
+
+        return new StackMapDecoder.StackMapFrameImpl(255, target, locals, stack);
+    }
+
+    /**
+     * The type of a stack value.
+     */
+    sealed interface VerificationTypeInfo {
+        int tag();
+    }
+
+    /**
+     * A simple stack value.
+     */
+    public enum SimpleVerificationTypeInfo implements VerificationTypeInfo {
+        ITEM_TOP(VT_TOP),
+        ITEM_INTEGER(VT_INTEGER),
+        ITEM_FLOAT(VT_FLOAT),
+        ITEM_DOUBLE(VT_DOUBLE),
+        ITEM_LONG(VT_LONG),
+        ITEM_NULL(VT_NULL),
+        ITEM_UNINITIALIZED_THIS(VT_UNINITIALIZED_THIS);
+
+
+        private final int tag;
+
+        SimpleVerificationTypeInfo(int tag) {
+            this.tag = tag;
+        }
+
+        @Override
+        public int tag() {
+            return tag;
+        }
+    }
+
+    /**
+     * A stack value for an object type.
+     */
+    sealed interface ObjectVerificationTypeInfo extends VerificationTypeInfo
+            permits StackMapDecoder.ObjectVerificationTypeInfoImpl {
+
+        public static ObjectVerificationTypeInfo of(ClassEntry className) {
+            return new StackMapDecoder.ObjectVerificationTypeInfoImpl(className);
+        }
+
+        public static ObjectVerificationTypeInfo of(ClassDesc classDesc) {
+            return of(TemporaryConstantPool.INSTANCE.classEntry(classDesc));
+        }
+
+        /**
+         * {@return the class of the value}
+         */
+        ClassEntry className();
+
+        default ClassDesc classSymbol() {
+            return className().asSymbol();
+        }
+    }
+
+    /**
+     * An uninitialized stack value.
+     */
+    sealed interface UninitializedVerificationTypeInfo extends VerificationTypeInfo
+            permits StackMapDecoder.UninitializedVerificationTypeInfoImpl {
+        Label newTarget();
+
+        public static UninitializedVerificationTypeInfo of(Label newTarget) {
+            return new StackMapDecoder.UninitializedVerificationTypeInfoImpl(newTarget);
+        }
+    }
+}