[groovy] 01/01: Add `$getLookup` method

[su...@apache.org]

This is an automated email from the ASF dual-hosted git repository.

sunlan pushed a commit to branch danielsun/tweak-build
in repository https://gitbox.apache.org/repos/asf/groovy.git

commit 42009a1d2bf42667fb22f4b47626ec90612ed323
Author: Daniel Sun <su...@apache.org>
AuthorDate: Tue Jun 15 19:16:59 2021 +0800

    Add `$getLookup` method
---
 .../org/codehaus/groovy/classgen/Verifier.java     | 38 +++++++++++++++++++---
 1 file changed, 33 insertions(+), 5 deletions(-)

diff --git a/src/main/java/org/codehaus/groovy/classgen/Verifier.java b/src/main/java/org/codehaus/groovy/classgen/Verifier.java
index b2761b0..8a98652 100644
--- a/src/main/java/org/codehaus/groovy/classgen/Verifier.java
+++ b/src/main/java/org/codehaus/groovy/classgen/Verifier.java
@@ -74,6 +74,7 @@ import org.objectweb.asm.MethodVisitor;
 import org.objectweb.asm.Opcodes;
 
 import java.beans.Transient;
+import java.lang.invoke.MethodHandles;
 import java.lang.reflect.Field;
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -98,6 +99,11 @@ import static org.apache.groovy.ast.tools.MethodNodeUtils.getCodeAsBlock;
 import static org.apache.groovy.ast.tools.MethodNodeUtils.getPropertyName;
 import static org.apache.groovy.ast.tools.MethodNodeUtils.methodDescriptorWithoutReturnType;
 import static org.codehaus.groovy.ast.AnnotationNode.METHOD_TARGET;
+import static org.codehaus.groovy.ast.ClassHelper.isObjectType;
+import static org.codehaus.groovy.ast.ClassHelper.isPrimitiveBoolean;
+import static org.codehaus.groovy.ast.ClassHelper.isPrimitiveDouble;
+import static org.codehaus.groovy.ast.ClassHelper.isPrimitiveLong;
+import static org.codehaus.groovy.ast.ClassHelper.isWrapperBoolean;
 import static org.codehaus.groovy.ast.tools.GeneralUtils.binX;
 import static org.codehaus.groovy.ast.tools.GeneralUtils.block;
 import static org.codehaus.groovy.ast.tools.GeneralUtils.bytecodeX;
@@ -114,11 +120,6 @@ import static org.codehaus.groovy.ast.tools.GenericsUtils.addMethodGenerics;
 import static org.codehaus.groovy.ast.tools.GenericsUtils.correctToGenericsSpec;
 import static org.codehaus.groovy.ast.tools.GenericsUtils.createGenericsSpec;
 import static org.codehaus.groovy.ast.tools.PropertyNodeUtils.adjustPropertyModifiersForMethod;
-import static org.codehaus.groovy.ast.ClassHelper.isObjectType;
-import static org.codehaus.groovy.ast.ClassHelper.isPrimitiveBoolean;
-import static org.codehaus.groovy.ast.ClassHelper.isPrimitiveDouble;
-import static org.codehaus.groovy.ast.ClassHelper.isPrimitiveLong;
-import static org.codehaus.groovy.ast.ClassHelper.isWrapperBoolean;
 
 /**
  * Verifies the AST node and adds any default AST code before bytecode generation occurs.
@@ -139,6 +140,7 @@ import static org.codehaus.groovy.ast.ClassHelper.isWrapperBoolean;
  *     <li>Property accessor methods</li>
  *     <li>Covariant methods</li>
  *     <li>Additional methods/constructors as needed for default parameters</li>
+ *     <li>{@link java.lang.invoke.MethodHandles.Lookup} getter</li>
  * </ul>
  */
 public class Verifier implements GroovyClassVisitor, Opcodes {
@@ -252,6 +254,8 @@ public class Verifier implements GroovyClassVisitor, Opcodes {
 
             addFastPathHelperFieldsAndHelperMethod(node, classInternalName, knownSpecialCase);
             if (!knownSpecialCase) addGroovyObjectInterfaceAndMethods(node, classInternalName);
+
+            addGetLookupMethod(node);
         }
 
         addDefaultConstructor(node);
@@ -354,6 +358,30 @@ public class Verifier implements GroovyClassVisitor, Opcodes {
         node.addConstructor(constructor);
     }
 
+    private void addGetLookupMethod(final ClassNode node) {
+        int modifiers = ACC_PUBLIC;
+        boolean nonStaticInnerClass = null != node.getOuterClass() && !node.isStaticClass();
+        if (!nonStaticInnerClass) {
+            // static method cannot be declared in non-static inner class util Java 16
+            modifiers |= ACC_STATIC;
+        }
+
+        node.addSyntheticMethod(
+                "$getLookup",
+                modifiers,
+                ClassHelper.make(MethodHandles.Lookup.class),
+                Parameter.EMPTY_ARRAY,
+                ClassNode.EMPTY_ARRAY,
+                new BytecodeSequence(new BytecodeInstruction() {
+                    @Override
+                    public void visit(final MethodVisitor mv) {
+                        mv.visitMethodInsn(INVOKESTATIC, "java/lang/invoke/MethodHandles", "lookup", "()Ljava/lang/invoke/MethodHandles$Lookup;", false);
+                        mv.visitInsn(ARETURN);
+                    }
+                })
+        );
+    }
+
     private void addStaticMetaClassField(final ClassNode node, final String classInternalName) {
         String _staticClassInfoFieldName = "$staticClassInfo";
         while (node.getDeclaredField(_staticClassInfoFieldName) != null)