8294972: Convert jdk.jlink internal plugins to use the Classfile API

Reviewed-by: mchung, alanb

src/java.base/share/classes/module-info.java

@@ -196,17 +196,18 @@ module java.base {
         jdk.jlink,
         jdk.jshell;
     exports jdk.internal.classfile.attribute to
-        jdk.jartool;
+        jdk.jartool,
+        jdk.jlink;
     exports jdk.internal.classfile.constantpool to
-        jdk.jartool;
+        jdk.jartool,
+        jdk.jlink;
     exports jdk.internal.classfile.instruction to
+        jdk.jlink,
         jdk.jshell;
     exports jdk.internal.org.objectweb.asm to
-        jdk.jfr,
+        jdk.jfr;
-        jdk.jlink;
     exports jdk.internal.org.objectweb.asm.tree to
-        jdk.jfr,
+        jdk.jfr;
-        jdk.jlink;
     exports jdk.internal.org.objectweb.asm.util to
         jdk.jfr;
     exports jdk.internal.org.objectweb.asm.commons to

src/jdk.jlink/share/classes/jdk/tools/jlink/internal/plugins/AbstractPlugin.java

@@ -35,7 +35,8 @@ import java.nio.file.Paths;
 import java.util.Locale;
 import java.util.MissingResourceException;
 import java.util.ResourceBundle;
-import jdk.internal.org.objectweb.asm.ClassReader;
+import jdk.internal.classfile.ClassModel;
+import jdk.internal.classfile.Classfile;
 import jdk.tools.jlink.plugin.ResourcePoolEntry;
 
 public abstract class AbstractPlugin implements Plugin {
@@ -84,10 +85,10 @@ public abstract class AbstractPlugin implements Plugin {
         }
     }
 
-    ClassReader newClassReader(String path, ResourcePoolEntry resource) {
+    ClassModel newClassReader(String path, ResourcePoolEntry resource, Classfile.Option... options) {
         byte[] content = resource.contentBytes();
         try {
-            return new ClassReader(content);
+            return Classfile.parse(content, options);
         } catch (Exception e) {
             if (JlinkTask.DEBUG) {
                 System.err.printf("Failed to parse class file: %s from resource of type %s\n", path,
@@ -99,9 +100,9 @@ public abstract class AbstractPlugin implements Plugin {
         }
     }
 
-    protected ClassReader newClassReader(String path, byte[] buf) {
+    protected ClassModel newClassReader(String path, byte[] buf, Classfile.Option... options) {
         try {
-            return new ClassReader(buf);
+            return Classfile.parse(buf, options);
         } catch (Exception e) {
             if (JlinkTask.DEBUG) {
                 System.err.printf("Failed to parse class file: %s\n", path);

src/jdk.jlink/share/classes/jdk/tools/jlink/internal/plugins/IncludeLocalesPlugin.java

@@ -35,12 +35,12 @@ import java.util.Objects;
 import java.util.Optional;
 import static java.util.ResourceBundle.Control;
 import java.util.Set;
+import java.util.function.IntUnaryOperator;
 import java.util.function.Predicate;
 import java.util.regex.Pattern;
 import java.util.stream.Collectors;
-import java.util.stream.IntStream;
 import java.util.stream.Stream;
-import jdk.internal.org.objectweb.asm.ClassReader;
+import static jdk.internal.classfile.Classfile.*;
 import jdk.tools.jlink.internal.ResourcePrevisitor;
 import jdk.tools.jlink.internal.StringTable;
 import jdk.tools.jlink.plugin.ResourcePoolModule;
@@ -159,10 +159,9 @@ public final class IncludeLocalesPlugin extends AbstractPlugin implements Resour
                     resource.type().equals(ResourcePoolEntry.Type.CLASS_OR_RESOURCE) &&
                     path.endsWith(".class")) {
                     byte[] bytes = resource.contentBytes();
-                    ClassReader cr = newClassReader(path, bytes);
+                    if (newClassReader(path, bytes).interfaces().stream()
-                    if (Arrays.stream(cr.getInterfaces())
+                        .anyMatch(i -> i.asInternalName().contains(METAINFONAME)) &&
-                        .anyMatch(i -> i.contains(METAINFONAME)) &&
+                        stripUnsupportedLocales(bytes)) {
-                        stripUnsupportedLocales(bytes, cr)) {
                         resource = resource.copyWithContent(bytes);
                     }
                 }
@@ -270,26 +269,49 @@ public final class IncludeLocalesPlugin extends AbstractPlugin implements Resour
             .toList();
     }
 
-    private boolean stripUnsupportedLocales(byte[] bytes, ClassReader cr) {
+    private boolean stripUnsupportedLocales(byte[] bytes) {
-        boolean[] modified = new boolean[1];
+        boolean modified = false;
-
+        // scan CP entries directly to read the bytes of UTF8 entries and
-        IntStream.range(1, cr.getItemCount())
+        // patch in place with unsupported locale tags stripped
-            .map(item -> cr.getItem(item))
+        IntUnaryOperator readU2 = p -> ((bytes[p] & 0xff) << 8) + (bytes[p + 1] & 0xff);
-            .forEach(itemIndex -> {
+        int cpLength = readU2.applyAsInt(8);
-                if (bytes[itemIndex - 1] == 1 &&         // UTF-8
+        int offset = 10;
-                    bytes[itemIndex + 2] == (byte)' ') { // fast check for leading space
+        for (int cpSlot=1; cpSlot<cpLength; cpSlot++) {
-                    int length = cr.readUnsignedShort(itemIndex);
+            switch (bytes[offset]) { //entry tag
-                    byte[] b = new byte[length];
+                case TAG_UTF8 -> {
-                    System.arraycopy(bytes, itemIndex + 2, b, 0, length);
+                    int length = readU2.applyAsInt(offset + 1);
-                    if (filterOutUnsupportedTags(b)) {
+                    if (bytes[offset + 3] == (byte)' ') { // fast check for leading space
-                        // copy back
+                        byte[] b = new byte[length];
-                        System.arraycopy(b, 0, bytes, itemIndex + 2, length);
+                        System.arraycopy(bytes, offset + 3, b, 0, length);
-                        modified[0] = true;
+                        if (filterOutUnsupportedTags(b)) {
+                            // copy back
+                            System.arraycopy(b, 0, bytes, offset + 3, length);
+                            modified = true;
+                        }
                     }
+                    offset += 3 + length;
                 }
-            });
+                case TAG_CLASS,
-
+                     TAG_STRING,
-        return modified[0];
+                     TAG_METHODTYPE,
+                     TAG_MODULE,
+                     TAG_PACKAGE -> offset += 3;
+                case TAG_METHODHANDLE -> offset += 4;
+                case TAG_INTEGER,
+                     TAG_FLOAT,
+                     TAG_FIELDREF,
+                     TAG_METHODREF,
+                     TAG_INTERFACEMETHODREF,
+                     TAG_NAMEANDTYPE,
+                     TAG_CONSTANTDYNAMIC,
+                     TAG_INVOKEDYNAMIC -> offset += 5;
+                case TAG_LONG,
+                     TAG_DOUBLE -> {offset += 9; cpSlot++;} //additional slot for double and long entries
+                default -> throw new IllegalArgumentException("Unknown constant pool entry: 0x"
+                        + Integer.toHexString(Byte.toUnsignedInt(bytes[offset])).toUpperCase(Locale.ROOT));
+            }
+        }
+        return modified;
     }
 
     private boolean filterOutUnsupportedTags(byte[] b) {

src/jdk.jlink/share/classes/jdk/tools/jlink/internal/plugins/StripJavaDebugAttributesPlugin.java

@@ -25,9 +25,14 @@
 package jdk.tools.jlink.internal.plugins;
 
 import java.util.function.Predicate;
+import jdk.internal.classfile.Classfile;
+import jdk.internal.classfile.ClassTransform;
+import jdk.internal.classfile.CodeTransform;
+import jdk.internal.classfile.MethodTransform;
+import jdk.internal.classfile.attribute.MethodParametersAttribute;
+import jdk.internal.classfile.attribute.SourceFileAttribute;
+import jdk.internal.classfile.attribute.SourceDebugExtensionAttribute;
 
-import jdk.internal.org.objectweb.asm.ClassReader;
-import jdk.internal.org.objectweb.asm.ClassWriter;
 import jdk.tools.jlink.plugin.ResourcePool;
 import jdk.tools.jlink.plugin.ResourcePoolBuilder;
 import jdk.tools.jlink.plugin.ResourcePoolEntry;
@@ -57,12 +62,17 @@ public final class StripJavaDebugAttributesPlugin extends AbstractPlugin {
                 String path = resource.path();
                 if (path.endsWith(".class")) {
                     if (path.endsWith("module-info.class")) {
-                        // XXX. Do we have debug info? Is Asm ready for module-info?
+                        // XXX. Do we have debug info?
                     } else {
-                        ClassReader reader = newClassReader(path, resource);
+                        byte[] content = newClassReader(path, resource,
-                        ClassWriter writer = new ClassWriter(ClassWriter.COMPUTE_MAXS);
+                                Classfile.Option.processDebug(false),
-                        reader.accept(writer, ClassReader.SKIP_DEBUG);
+                                Classfile.Option.processLineNumbers(false)).transform(ClassTransform
-                        byte[] content = writer.toByteArray();
+                                        .dropping(cle -> cle instanceof SourceFileAttribute
+                                                      || cle instanceof SourceDebugExtensionAttribute)
+                                        .andThen(ClassTransform.transformingMethods(MethodTransform
+                                                .dropping(me -> me instanceof MethodParametersAttribute)
+                                                .andThen(MethodTransform
+                                                        .transformingCode(CodeTransform.ACCEPT_ALL)))));
                         res = resource.copyWithContent(content);
                     }
                 }

src/jdk.jlink/share/classes/jdk/tools/jlink/internal/plugins/VersionPropsPlugin.java

@@ -26,12 +26,13 @@
 package jdk.tools.jlink.internal.plugins;
 
 import java.util.Map;
+import jdk.internal.classfile.ClassTransform;
+import jdk.internal.classfile.CodeBuilder;
+import jdk.internal.classfile.CodeElement;
+import jdk.internal.classfile.Instruction;
+import jdk.internal.classfile.instruction.FieldInstruction;
+import jdk.internal.classfile.CodeTransform;
 
-import jdk.internal.org.objectweb.asm.ClassReader;
-import jdk.internal.org.objectweb.asm.ClassVisitor;
-import jdk.internal.org.objectweb.asm.ClassWriter;
-import jdk.internal.org.objectweb.asm.MethodVisitor;
-import jdk.internal.org.objectweb.asm.Opcodes;
 import jdk.tools.jlink.plugin.ResourcePool;
 import jdk.tools.jlink.plugin.ResourcePoolBuilder;
 import jdk.tools.jlink.plugin.ResourcePoolEntry;
@@ -96,63 +97,38 @@ abstract class VersionPropsPlugin extends AbstractPlugin {
 
     private boolean redefined = false;
 
+    @SuppressWarnings("deprecation")
     private byte[] redefine(String path, byte[] classFile) {
+        return newClassReader(path, classFile).transform(ClassTransform.transformingMethodBodies(
+                mm -> mm.methodName().equalsString("<clinit>"),
+                new CodeTransform() {
+                    private CodeElement pendingLDC = null;
 
-        var cr = newClassReader(path, classFile);
+                    private void flushPendingLDC(CodeBuilder cob) {
-        var cw = new ClassWriter(0);
+                        if (pendingLDC != null) {
+                            cob.accept(pendingLDC);
+                            pendingLDC = null;
+                        }
+                    }
 
-        cr.accept(new ClassVisitor(Opcodes.ASM7, cw) {
+                    @Override
-
+                    public void accept(CodeBuilder cob, CodeElement coe) {
-                @Override
+                        if (coe instanceof Instruction ins) {
-                public MethodVisitor visitMethod(int access,
+                            switch (ins.opcode()) {
-                                                 String name,
+                                case LDC, LDC_W, LDC2_W -> {
-                                                 String desc,
+                                    flushPendingLDC(cob);
-                                                 String sig,
+                                    pendingLDC = coe;
-                                                 String[] xs)
-                {
-                    if (name.equals("<clinit>"))
-                        return new MethodVisitor(Opcodes.ASM7,
-                                                 super.visitMethod(access,
-                                                                   name,
-                                                                   desc,
-                                                                   sig,
-                                                                   xs))
-                            {
-                                private Object pendingLDC = null;
-
-                                private void flushPendingLDC() {
-                                    if (pendingLDC != null) {
-                                        super.visitLdcInsn(pendingLDC);
-                                        pendingLDC = null;
-                                    }
                                 }
-
+                                case INVOKEVIRTUAL, INVOKESPECIAL, INVOKESTATIC, INVOKEINTERFACE -> {
-                                @Override
+                                    flushPendingLDC(cob);
-                                public void visitLdcInsn(Object value) {
+                                    cob.accept(coe);
-                                    flushPendingLDC();
-                                    pendingLDC = value;
                                 }
-
+                                case GETSTATIC, GETFIELD, PUTFIELD -> {
-                                @Override
+                                    flushPendingLDC(cob);
-                                public void visitMethodInsn(int opcode,
+                                    cob.accept(coe);
-                                                            String owner,
-                                                            String name,
-                                                            String descriptor,
-                                                            boolean isInterface) {
-                                    flushPendingLDC();
-                                    super.visitMethodInsn(opcode, owner, name,
-                                                          descriptor, isInterface);
                                 }
-
+                                case PUTSTATIC -> {
-                                @Override
+                                    if (((FieldInstruction)coe).name().equalsString(field)) {
-                                public void visitFieldInsn(int opcode,
-                                                           String owner,
-                                                           String name,
-                                                           String desc)
-                                {
-                                    if (opcode == Opcodes.PUTSTATIC
-                                        && name.equals(field))
-                                    {
                                         // assert that there is a pending ldc
                                         // for the old value
                                         if (pendingLDC == null) {
@@ -164,24 +140,20 @@ abstract class VersionPropsPlugin extends AbstractPlugin {
                                         // forget about it
                                         pendingLDC = null;
                                         // and add an ldc for the new value
-                                        super.visitLdcInsn(value);
+                                        cob.constantInstruction(value);
                                         redefined = true;
                                     } else {
-                                        flushPendingLDC();
+                                        flushPendingLDC(cob);
                                     }
-                                    super.visitFieldInsn(opcode, owner,
+                                    cob.accept(coe);
-                                                         name, desc);
                                 }
-
+                                default -> cob.accept(coe);
-                        };
+                            }
-                    else
+                        } else {
-                        return super.visitMethod(access, name, desc, sig, xs);
+                            cob.accept(coe);
-                }
+                        }
-
+                    }
-            }, 0);
+                }));
-
-        return cw.toByteArray();
-
     }
 
     @Override
@@ -198,5 +170,4 @@ abstract class VersionPropsPlugin extends AbstractPlugin {
             throw new AssertionError(field);
         return out.build();
     }
-
 }