test/jdk/java/lang/invoke/common/test/java/lang/invoke/lib/InstructionHelper.java

*** 23,19 ***
  
  package test.java.lang.invoke.lib;
  
  import java.lang.classfile.ClassBuilder;
  import java.lang.classfile.ClassFile;
  import java.lang.classfile.TypeKind;
  
  import java.lang.constant.*;
  import java.lang.invoke.MethodHandle;
  import java.lang.invoke.MethodHandles;
  import java.lang.invoke.MethodType;
- import java.util.concurrent.atomic.AtomicInteger;
- 
  import static java.lang.invoke.MethodType.fromMethodDescriptorString;
  
  public class InstructionHelper {
  
      static final AtomicInteger COUNT = new AtomicInteger();
  
--- 23,20 ---
  
  package test.java.lang.invoke.lib;
  
  import java.lang.classfile.ClassBuilder;
  import java.lang.classfile.ClassFile;
+ import java.lang.classfile.CodeBuilder;
  import java.lang.classfile.TypeKind;
  
  import java.lang.constant.*;
  import java.lang.invoke.MethodHandle;
  import java.lang.invoke.MethodHandles;
  import java.lang.invoke.MethodType;
  import static java.lang.invoke.MethodType.fromMethodDescriptorString;
+ import java.util.concurrent.atomic.AtomicInteger;
+ import java.util.function.Consumer;
  
  public class InstructionHelper {
  
      static final AtomicInteger COUNT = new AtomicInteger();
  

*** 133,6 ***
--- 134,29 ---
      public static ClassDesc classDesc(Class<?> c, String suffix) {
          StringBuilder sb = new StringBuilder(c.descriptorString());
          String classDescStr = sb.insert(sb.length() - 1, suffix).toString();
          return ClassDesc.ofDescriptor(classDescStr);
      }
+ 
+ 
+     public static MethodHandle buildMethodHandle(MethodHandles.Lookup l, String methodName, MethodType methodType, Consumer<? super CodeBuilder> builder) {
+         ClassDesc genClassDesc = classDesc(l.lookupClass(), "$Code_" + COUNT.getAndIncrement());
+         return buildMethodHandle(l, genClassDesc, methodName, methodType, builder);
+     }
+ 
+     public static MethodHandle buildMethodHandle(MethodHandles.Lookup l, ClassDesc classDesc, String methodName, MethodType methodType, Consumer<? super CodeBuilder> builder) {
+         try {
+             byte[] bytes = ClassFile.of().build(classDesc, classBuilder -> {
+                 classBuilder.withMethod(methodName,
+                                         MethodTypeDesc.ofDescriptor(methodType.toMethodDescriptorString()),
+                                         ClassFile.ACC_PUBLIC + ClassFile.ACC_STATIC,
+                                         methodBuilder -> methodBuilder.withCode(builder));
+             });
+             Class<?> clazz = l.defineClass(bytes);
+             return l.findStatic(clazz, methodName, methodType);
+         } catch (Throwable t) {
+             t.printStackTrace();
+             throw new RuntimeException("Failed to buildMethodHandle: " + methodName + " type " + methodType);
+         }
+     }
+ 
  }