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src/java.base/share/classes/java/lang/invoke/GenerateJLIClassesHelper.java

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rev 15353 : 8164044: Generate corresponding simple DelegatingMethodHandles when generating a DirectMethodHandle at link time
Reviewed-by: vlivanov, mhaupt, shade


  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package java.lang.invoke;
  27 
  28 import java.util.Map;
  29 import jdk.internal.org.objectweb.asm.ClassWriter;
  30 import jdk.internal.org.objectweb.asm.Opcodes;
  31 



  32 /**
  33  * Helper class to assist the GenerateJLIClassesPlugin to get access to
  34  * generate classes ahead of time.
  35  */
  36 class GenerateJLIClassesHelper {
  37 
  38     static byte[] generateDMHClassBytes(String className,
  39             MethodType[] methodTypes, int[] types) {
  40         LambdaForm[] forms = new LambdaForm[methodTypes.length];

  41         for (int i = 0; i < forms.length; i++) {
  42             forms[i] = DirectMethodHandle.makePreparedLambdaForm(methodTypes[i],
  43                                                                  types[i]);
  44             methodTypes[i] = forms[i].methodType();




























  45         }
  46         return generateCodeBytesForLFs(className, forms, methodTypes);



  47     }
  48 
  49     /*
  50      * Generate customized code for a set of LambdaForms of specified types into
  51      * a class with a specified name.
  52      */
  53     private static byte[] generateCodeBytesForLFs(String className,
  54             LambdaForm[] forms, MethodType[] types) {
  55         assert(forms.length == types.length);
  56 
  57         ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_MAXS + ClassWriter.COMPUTE_FRAMES);
  58         cw.visit(Opcodes.V1_8, Opcodes.ACC_PRIVATE + Opcodes.ACC_FINAL + Opcodes.ACC_SUPER,
  59                 className, null, InvokerBytecodeGenerator.INVOKER_SUPER_NAME, null);
  60         cw.visitSource(className.substring(className.lastIndexOf('/') + 1), null);

  61         for (int i = 0; i < forms.length; i++) {








  62             InvokerBytecodeGenerator g
  63                     = new InvokerBytecodeGenerator(className, forms[i], types[i]);
  64             g.setClassWriter(cw);
  65             g.addMethod();
  66         }
  67         return cw.toByteArray();















  68     }
  69 
  70     static Map.Entry<String, byte[]> generateConcreteBMHClassBytes(
  71             final String types) {
  72         for (char c : types.toCharArray()) {
  73             if ("LIJFD".indexOf(c) < 0) {
  74                 throw new IllegalArgumentException("All characters must "
  75                         + "correspond to a basic field type: LIJFD");
  76             }
  77         }
  78         String shortTypes = LambdaForm.shortenSignature(types);
  79         final String className =
  80                 BoundMethodHandle.Factory.speciesInternalClassName(shortTypes);
  81         return Map.entry(className,
  82                          BoundMethodHandle.Factory.generateConcreteBMHClassBytes(
  83                                  shortTypes, types, className));
  84     }
  85 }


  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package java.lang.invoke;
  27 
  28 import java.util.Map;
  29 import jdk.internal.org.objectweb.asm.ClassWriter;
  30 import jdk.internal.org.objectweb.asm.Opcodes;
  31 
  32 import java.util.ArrayList;
  33 import java.util.HashSet;
  34 
  35 /**
  36  * Helper class to assist the GenerateJLIClassesPlugin to get access to
  37  * generate classes ahead of time.
  38  */
  39 class GenerateJLIClassesHelper {
  40 
  41     static byte[] generateDirectMethodHandleHolderClassBytes(String className,
  42             MethodType[] methodTypes, int[] types) {
  43         LambdaForm[] forms = new LambdaForm[methodTypes.length];
  44         String[] names = new String[methodTypes.length];
  45         for (int i = 0; i < forms.length; i++) {
  46             forms[i] = DirectMethodHandle.makePreparedLambdaForm(methodTypes[i],
  47                                                                  types[i]);
  48             names[i] = forms[i].kind.defaultLambdaName;
  49         }
  50         return generateCodeBytesForLFs(className, names, forms);
  51     }
  52 
  53     static byte[] generateDelegatingMethodHandleHolderClassBytes(String className,
  54             MethodType[] methodTypes) {
  55 
  56         HashSet<MethodType> dedupSet = new HashSet<>();
  57         ArrayList<LambdaForm> forms = new ArrayList<>();
  58         ArrayList<String> names = new ArrayList<>();
  59         for (int i = 0; i < methodTypes.length; i++) {
  60             // generate methods representing the DelegatingMethodHandle
  61             if (dedupSet.add(methodTypes[i])) {
  62                 // reinvokers are variant with the associated SpeciesData
  63                 // and shape of the target LF, but we can easily pregenerate
  64                 // the basic reinvokers associated with Species_L. Ultimately we
  65                 // may want to consider pregenerating more of these, which will
  66                 // require an even more complex naming scheme
  67                 LambdaForm reinvoker = makeReinvokerFor(methodTypes[i]);
  68                 forms.add(reinvoker);
  69                 String speciesSig = BoundMethodHandle
  70                         .speciesData(reinvoker).fieldSignature();
  71                 assert(speciesSig.equals("L"));
  72                 names.add(reinvoker.kind.defaultLambdaName + "_" + speciesSig);
  73 
  74                 LambdaForm delegate = makeDelegateFor(methodTypes[i]);
  75                 forms.add(delegate);
  76                 names.add(delegate.kind.defaultLambdaName);
  77             }
  78         }
  79         return generateCodeBytesForLFs(className,
  80                 names.toArray(new String[0]),
  81                 forms.toArray(new LambdaForm[0]));
  82     }
  83 
  84     /*
  85      * Generate customized code for a set of LambdaForms of specified types into
  86      * a class with a specified name.
  87      */
  88     private static byte[] generateCodeBytesForLFs(String className,
  89             String[] names, LambdaForm[] forms) {

  90 
  91         ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_MAXS + ClassWriter.COMPUTE_FRAMES);
  92         cw.visit(Opcodes.V1_8, Opcodes.ACC_PRIVATE + Opcodes.ACC_FINAL + Opcodes.ACC_SUPER,
  93                 className, null, InvokerBytecodeGenerator.INVOKER_SUPER_NAME, null);
  94         cw.visitSource(className.substring(className.lastIndexOf('/') + 1), null);
  95 
  96         for (int i = 0; i < forms.length; i++) {
  97             addMethod(className, names[i], forms[i],
  98                     forms[i].methodType(), cw);
  99         }
 100         return cw.toByteArray();
 101     }
 102 
 103     private static void addMethod(String className, String methodName, LambdaForm form,
 104             MethodType type, ClassWriter cw) {
 105         InvokerBytecodeGenerator g
 106                 = new InvokerBytecodeGenerator(className, methodName, form, type);
 107         g.setClassWriter(cw);
 108         g.addMethod();
 109     }
 110 
 111     private static LambdaForm makeReinvokerFor(MethodType type) {
 112         MethodHandle emptyHandle = MethodHandles.empty(type);
 113         return DelegatingMethodHandle.makeReinvokerForm(emptyHandle,
 114                 MethodTypeForm.LF_REBIND,
 115                 BoundMethodHandle.speciesData_L(),
 116                 BoundMethodHandle.speciesData_L().getterFunction(0));
 117     }
 118 
 119     private static LambdaForm makeDelegateFor(MethodType type) {
 120         MethodHandle handle = MethodHandles.empty(type);
 121         return DelegatingMethodHandle.makeReinvokerForm(
 122                 handle,
 123                 MethodTypeForm.LF_DELEGATE,
 124                 DelegatingMethodHandle.class,
 125                 DelegatingMethodHandle.NF_getTarget);
 126     }
 127 
 128     static Map.Entry<String, byte[]> generateConcreteBMHClassBytes(
 129             final String types) {
 130         for (char c : types.toCharArray()) {
 131             if ("LIJFD".indexOf(c) < 0) {
 132                 throw new IllegalArgumentException("All characters must "
 133                         + "correspond to a basic field type: LIJFD");
 134             }
 135         }
 136         String shortTypes = LambdaForm.shortenSignature(types);
 137         final String className =
 138                 BoundMethodHandle.Factory.speciesInternalClassName(shortTypes);
 139         return Map.entry(className,
 140                          BoundMethodHandle.Factory.generateConcreteBMHClassBytes(
 141                                  shortTypes, types, className));
 142     }
 143 }
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