BEGIN_PUBLIC

PR #18406: Teach ijar about dynamic constants.

Imported from GitHub PR #18406

END_PUBLIC

PiperOrigin-RevId: 540750474
Change-Id: If61bcaaf018b92a1bf87335c1075c28294932b1f

third_party/ijar/classfile.cc

@@ -53,22 +53,23 @@ std::string ToString(const T& value) {
 
 namespace devtools_ijar {
 
-// See Table 4.3 in JVM Spec.
+// See Table 4.4 in JVM 17 Spec.
 enum CONSTANT {
-  CONSTANT_Class              = 7,
-  CONSTANT_FieldRef           = 9,
-  CONSTANT_Methodref          = 10,
+  CONSTANT_Class = 7,
+  CONSTANT_FieldRef = 9,
+  CONSTANT_Methodref = 10,
   CONSTANT_Interfacemethodref = 11,
-  CONSTANT_String             = 8,
-  CONSTANT_Integer            = 3,
-  CONSTANT_Float              = 4,
-  CONSTANT_Long               = 5,
-  CONSTANT_Double             = 6,
-  CONSTANT_NameAndType        = 12,
-  CONSTANT_Utf8               = 1,
-  CONSTANT_MethodHandle       = 15,
-  CONSTANT_MethodType         = 16,
-  CONSTANT_InvokeDynamic      = 18
+  CONSTANT_String = 8,
+  CONSTANT_Integer = 3,
+  CONSTANT_Float = 4,
+  CONSTANT_Long = 5,
+  CONSTANT_Double = 6,
+  CONSTANT_NameAndType = 12,
+  CONSTANT_Utf8 = 1,
+  CONSTANT_MethodHandle = 15,
+  CONSTANT_MethodType = 16,
+  CONSTANT_Dynamic = 17,
+  CONSTANT_InvokeDynamic = 18
 };
 
 // See Tables 4.1, 4.4, 4.5 in JVM Spec.
@@ -390,12 +391,32 @@ struct Constant_MethodType : Constant
 };
 
 // See sec.4.4.10 of JVM spec.
-struct Constant_InvokeDynamic : Constant
-{
-  Constant_InvokeDynamic(u2 bootstrap_method_attr_index, u2 name_and_type_index) :
-      Constant(CONSTANT_InvokeDynamic),
-      bootstrap_method_attr_index_(bootstrap_method_attr_index),
-      name_and_type_index_(name_and_type_index) {}
+struct Constant_Dynamic : Constant {
+  Constant_Dynamic(u2 bootstrap_method_attr_index, u2 name_and_type_index)
+      : Constant(CONSTANT_Dynamic),
+        bootstrap_method_attr_index_(bootstrap_method_attr_index),
+        name_and_type_index_(name_and_type_index) {}
+
+  void Write(u1 *&p) {
+    put_u1(p, tag_);
+    put_u2be(p, bootstrap_method_attr_index_);
+    put_u2be(p, name_and_type_index_);
+  }
+
+  std::string Display() {
+    return "Constant_Dynamic::" + ToString(bootstrap_method_attr_index_) +
+           "::" + constant(name_and_type_index_)->Display();
+  }
+
+  u2 bootstrap_method_attr_index_;
+  u2 name_and_type_index_;
+};
+
+struct Constant_InvokeDynamic : Constant {
+  Constant_InvokeDynamic(u2 bootstrap_method_attr_index, u2 name_and_type_index)
+      : Constant(CONSTANT_InvokeDynamic),
+        bootstrap_method_attr_index_(bootstrap_method_attr_index),
+        name_and_type_index_(name_and_type_index) {}
 
   void Write(u1 *&p) {
     put_u1(p, tag_);
@@ -1677,6 +1698,13 @@ bool ClassFile::ReadConstantPool(const u1 *&p) {
         const_pool_in.push_back(new Constant_MethodType(descriptor_index));
         break;
       }
+      case CONSTANT_Dynamic: {
+        u2 bootstrap_method_attr = get_u2be(p);
+        u2 name_name_type_index = get_u2be(p);
+        const_pool_in.push_back(
+            new Constant_Dynamic(bootstrap_method_attr, name_name_type_index));
+        break;
+      }
       case CONSTANT_InvokeDynamic: {
         u2 bootstrap_method_attr = get_u2be(p);
         u2 name_name_type_index = get_u2be(p);
@@ -1685,7 +1713,7 @@ bool ClassFile::ReadConstantPool(const u1 *&p) {
         break;
       }
       default: {
-        fprintf(stderr, "Unknown constant: %02x. Passing class through.\n",
+        fprintf(stderr, "Unknown constant: %hhu. Passing class through.\n",
                 tag);
         return false;
       }

third_party/ijar/test/BUILD

@@ -46,6 +46,7 @@ sh_test(
         # Intentionally bad test JAR: file count in central directory
         # wrong.
         "libwrongcentraldir.jar",
+        ":dynamic_constant.jar",
         "@bazel_tools//tools/jdk:current_java_runtime",
     ],
     shard_count = 5,
@@ -204,6 +205,21 @@ genrule(
     tools = ["gen_source_debug_extension"],
 )
 
+java_binary(
+    name = "gen_dynamic_constant",
+    srcs = ["GenDynamicConstant.java"],
+    main_class = "test.GenDynamicConstant",
+    deps = ["//third_party:asm"],
+)
+
+genrule(
+    name = "gen_dynamic_constant_jar",
+    srcs = [],
+    outs = ["dynamic_constant.jar"],
+    cmd = "$(location :gen_dynamic_constant) $@",
+    tools = [":gen_dynamic_constant"],
+)
+
 java_library(
     name = "local_and_anonymous_lib",
     srcs = ["LocalAndAnonymous.java"],

third_party/ijar/test/GenDynamicConstant.java

@@ -0,0 +1,76 @@
+// Copyright 2023 The Bazel Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package test;
+
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.lang.invoke.ConstantBootstraps;
+import java.util.jar.JarOutputStream;
+import java.util.zip.ZipEntry;
+import org.objectweb.asm.ClassWriter;
+import org.objectweb.asm.ConstantDynamic;
+import org.objectweb.asm.Handle;
+import org.objectweb.asm.MethodVisitor;
+import org.objectweb.asm.Opcodes;
+import org.objectweb.asm.Type;
+
+public class GenDynamicConstant {
+  public static void main(String[] args) throws IOException {
+    try (JarOutputStream jos = new JarOutputStream(new FileOutputStream(args[0]))) {
+      jos.putNextEntry(new ZipEntry("dynamicconstant/Test.class"));
+      jos.write(dump());
+    }
+  }
+
+  public static byte[] dump() {
+    ClassWriter cw = new ClassWriter(0);
+    MethodVisitor mv;
+
+    cw.visit(
+        Opcodes.V16,
+        Opcodes.ACC_PUBLIC + Opcodes.ACC_SUPER,
+        "dynamicconstant/Test",
+        null,
+        "java/lang/Object",
+        null);
+
+    cw.visitEnd();
+
+    var desc = Type.INT_TYPE.getDescriptor();
+    var get =
+        cw.visitMethod(Opcodes.ACC_PUBLIC | Opcodes.ACC_STATIC, "get", "()" + desc, null, null);
+    get.visitInsn(Opcodes.ICONST_5);
+    get.visitInsn(Opcodes.IRETURN);
+    get.visitMaxs(1, 0);
+    get.visitEnd();
+    var invokeHandle =
+        new Handle(
+            Opcodes.H_INVOKESTATIC,
+            Type.getInternalName(ConstantBootstraps.class),
+            "invoke",
+            "(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/Class;Ljava/lang/invoke/MethodHandle;[Ljava/lang/Object;)Ljava/lang/Object;",
+            false);
+    var handle =
+        new Handle(Opcodes.H_INVOKESTATIC, "dynamicconstant/Test", "get", "()" + desc, false);
+    var run =
+        cw.visitMethod(Opcodes.ACC_PUBLIC | Opcodes.ACC_STATIC, "run", "()" + desc, null, null);
+    run.visitLdcInsn(new ConstantDynamic("const", desc, invokeHandle, handle));
+    run.visitInsn(Opcodes.IRETURN);
+    run.visitMaxs(1, 0);
+    run.visitEnd();
+
+    return cw.toByteArray();
+  }
+}

third_party/ijar/test/ijar_test.sh

@@ -85,6 +85,8 @@ CENTRAL_DIR_LARGEST_REGULAR=$IJAR_SRCDIR/test/largest_regular.jar
 CENTRAL_DIR_SMALLEST_ZIP64=$IJAR_SRCDIR/test/smallest_zip64.jar
 CENTRAL_DIR_ZIP64=$IJAR_SRCDIR/test/definitely_zip64.jar
 KEEP_FOR_COMPILE=$IJAR_SRCDIR/test/keep_for_compile_lib.jar
+DYNAMICCONSTANT_JAR=$IJAR_SRCDIR/test/dynamic_constant.jar
+DYNAMICCONSTANT_IJAR=$TEST_TMPDIR/dynamic_constant_interface.jar
 
 #### Setup
 
@@ -522,6 +524,13 @@ function test_method_parameters_attribute() {
   expect_log "MethodParameters" "MethodParameters not preserved!"
 }
 
+function test_dynamic_constant() {
+  $IJAR $DYNAMICCONSTANT_JAR $DYNAMICCONSTANT_IJAR || fail "ijar failed"
+
+  lines=$($JAVAP -c -private -classpath $DYNAMICCONSTANT_IJAR dynamicconstant.Test | grep -c Code: || true)
+  check_eq 0 $lines "Interface jar should have no method bodies!"
+}
+
 function test_nestmates_attribute() {
   # Check that Java 11 NestMates attributes are preserved
   $IJAR $NESTMATES_JAR $NESTMATES_IJAR || fail "ijar failed"