src/share/classes/java/lang/invoke/LambdaForm.java
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src/share/classes/java/lang/invoke/LambdaForm.java

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rev 9490 : 8037210: Get rid of char-based descriptions 'J' of basic types
Reviewed-by: ?


  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.lang.annotation.*;
  29 import java.lang.reflect.Method;
  30 import java.util.Map;
  31 import java.util.List;
  32 import java.util.Arrays;
  33 import java.util.ArrayList;
  34 import java.util.HashMap;
  35 import java.util.concurrent.ConcurrentHashMap;
  36 import sun.invoke.util.Wrapper;



  37 import static java.lang.invoke.MethodHandleStatics.*;
  38 import static java.lang.invoke.MethodHandleNatives.Constants.*;
  39 import java.lang.reflect.Field;
  40 import java.util.Objects;
  41 
  42 /**
  43  * The symbolic, non-executable form of a method handle's invocation semantics.
  44  * It consists of a series of names.
  45  * The first N (N=arity) names are parameters,
  46  * while any remaining names are temporary values.
  47  * Each temporary specifies the application of a function to some arguments.
  48  * The functions are method handles, while the arguments are mixes of
  49  * constant values and local names.
  50  * The result of the lambda is defined as one of the names, often the last one.
  51  * <p>
  52  * Here is an approximate grammar:
  53  * <blockquote><pre>{@code
  54  * LambdaForm = "(" ArgName* ")=>{" TempName* Result "}"
  55  * ArgName = "a" N ":" T
  56  * TempName = "t" N ":" T "=" Function "(" Argument* ");"
  57  * Function = ConstantValue
  58  * Argument = NameRef | ConstantValue
  59  * Result = NameRef | "void"
  60  * NameRef = "a" N | "t" N


 113  * (a0:L, a1:L)=>{ t2:L = BoundMethodHandle#argument(a0);
 114  *                 t3:L = Class#cast(t2,a1); t3 }
 115  *     == invoker for identity method handle which performs cast
 116  * }</pre></blockquote>
 117  * <p>
 118  * @author John Rose, JSR 292 EG
 119  */
 120 class LambdaForm {
 121     final int arity;
 122     final int result;
 123     @Stable final Name[] names;
 124     final String debugName;
 125     MemberName vmentry;   // low-level behavior, or null if not yet prepared
 126     private boolean isCompiled;
 127 
 128     // Caches for common structural transforms:
 129     LambdaForm[] bindCache;
 130 
 131     public static final int VOID_RESULT = -1, LAST_RESULT = -2;
 132 




























































































 133     LambdaForm(String debugName,
 134                int arity, Name[] names, int result) {
 135         assert(namesOK(arity, names));
 136         this.arity = arity;
 137         this.result = fixResult(result, names);
 138         this.names = names.clone();
 139         this.debugName = debugName;
 140         normalize();
 141     }
 142 
 143     LambdaForm(String debugName,
 144                int arity, Name[] names) {
 145         this(debugName,
 146              arity, names, LAST_RESULT);
 147     }
 148 
 149     LambdaForm(String debugName,
 150                Name[] formals, Name[] temps, Name result) {
 151         this(debugName,
 152              formals.length, buildNames(formals, temps, result), LAST_RESULT);
 153     }
 154 
 155     private static Name[] buildNames(Name[] formals, Name[] temps, Name result) {
 156         int arity = formals.length;
 157         int length = arity + temps.length + (result == null ? 0 : 1);
 158         Name[] names = Arrays.copyOf(formals, length);
 159         System.arraycopy(temps, 0, names, arity, temps.length);
 160         if (result != null)
 161             names[length - 1] = result;
 162         return names;
 163     }
 164 
 165     private LambdaForm(String sig) {
 166         // Make a blank lambda form, which returns a constant zero or null.
 167         // It is used as a template for managing the invocation of similar forms that are non-empty.
 168         // Called only from getPreparedForm.
 169         assert(isValidSignature(sig));
 170         this.arity = signatureArity(sig);
 171         this.result = (signatureReturn(sig) == 'V' ? -1 : arity);
 172         this.names = buildEmptyNames(arity, sig);
 173         this.debugName = "LF.zero";
 174         assert(nameRefsAreLegal());
 175         assert(isEmpty());
 176         assert(sig.equals(basicTypeSignature()));
 177     }
 178 
 179     private static Name[] buildEmptyNames(int arity, String basicTypeSignature) {
 180         assert(isValidSignature(basicTypeSignature));
 181         int resultPos = arity + 1;  // skip '_'
 182         if (arity < 0 || basicTypeSignature.length() != resultPos+1)
 183             throw new IllegalArgumentException("bad arity for "+basicTypeSignature);
 184         int numRes = (basicTypeSignature.charAt(resultPos) == 'V' ? 0 : 1);
 185         Name[] names = arguments(numRes, basicTypeSignature.substring(0, arity));
 186         for (int i = 0; i < numRes; i++) {
 187             names[arity + i] = constantZero(arity + i, basicTypeSignature.charAt(resultPos + i));

 188         }
 189         return names;
 190     }
 191 
 192     private static int fixResult(int result, Name[] names) {
 193         if (result >= 0) {
 194             if (names[result].type == 'V')
 195                 return -1;
 196         } else if (result == LAST_RESULT) {
 197             return names.length - 1;
 198         }
 199         return result;
 200     }
 201 
































 202     private static boolean namesOK(int arity, Name[] names) {
 203         for (int i = 0; i < names.length; i++) {
 204             Name n = names[i];
 205             assert(n != null) : "n is null";
 206             if (i < arity)
 207                 assert( n.isParam()) : n + " is not param at " + i;
 208             else
 209                 assert(!n.isParam()) : n + " is param at " + i;
 210         }
 211         return true;
 212     }
 213 
 214     /** Renumber and/or replace params so that they are interned and canonically numbered. */
 215     private void normalize() {
 216         Name[] oldNames = null;
 217         int changesStart = 0;
 218         for (int i = 0; i < names.length; i++) {
 219             Name n = names[i];
 220             if (!n.initIndex(i)) {
 221                 if (oldNames == null) {


 277             for (Object arg : n.arguments) {
 278                 if (arg instanceof Name) {
 279                     Name n2 = (Name) arg;
 280                     int i2 = n2.index;
 281                     assert(0 <= i2 && i2 < names.length) : n.debugString() + ": 0 <= i2 && i2 < names.length: 0 <= " + i2 + " < " + names.length;
 282                     assert(names[i2] == n2) : Arrays.asList("-1-", i, "-2-", n.debugString(), "-3-", i2, "-4-", n2.debugString(), "-5-", names[i2].debugString(), "-6-", this);
 283                     assert(i2 < i);  // ref must come after def!
 284                 }
 285             }
 286         }
 287         return true;
 288     }
 289 
 290     /** Invoke this form on the given arguments. */
 291     // final Object invoke(Object... args) throws Throwable {
 292     //     // NYI: fit this into the fast path?
 293     //     return interpretWithArguments(args);
 294     // }
 295 
 296     /** Report the return type. */
 297     char returnType() {
 298         if (result < 0)  return 'V';
 299         Name n = names[result];
 300         return n.type;
 301     }
 302 
 303     /** Report the N-th argument type. */
 304     char parameterType(int n) {
 305         assert(n < arity);
 306         return names[n].type;
 307     }
 308 
 309     /** Report the arity. */
 310     int arity() {
 311         return arity;
 312     }
 313 
 314     /** Return the method type corresponding to my basic type signature. */
 315     MethodType methodType() {
 316         return signatureType(basicTypeSignature());
 317     }
 318     /** Return ABC_Z, where the ABC are parameter type characters, and Z is the return type character. */
 319     final String basicTypeSignature() {
 320         StringBuilder buf = new StringBuilder(arity() + 3);
 321         for (int i = 0, a = arity(); i < a; i++)
 322             buf.append(parameterType(i));
 323         return buf.append('_').append(returnType()).toString();
 324     }
 325     static int signatureArity(String sig) {
 326         assert(isValidSignature(sig));
 327         return sig.indexOf('_');
 328     }
 329     static char signatureReturn(String sig) {
 330         return sig.charAt(signatureArity(sig)+1);
 331     }
 332     static boolean isValidSignature(String sig) {
 333         int arity = sig.indexOf('_');
 334         if (arity < 0)  return false;  // must be of the form *_*
 335         int siglen = sig.length();
 336         if (siglen != arity + 2)  return false;  // *_X
 337         for (int i = 0; i < siglen; i++) {
 338             if (i == arity)  continue;  // skip '_'
 339             char c = sig.charAt(i);
 340             if (c == 'V')
 341                 return (i == siglen - 1 && arity == siglen - 2);
 342             if (ALL_TYPES.indexOf(c) < 0)  return false; // must be [LIJFD]
 343         }
 344         return true;  // [LIJFD]*_[LIJFDV]
 345     }
 346     static Class<?> typeClass(char t) {
 347         switch (t) {
 348         case 'I': return int.class;
 349         case 'J': return long.class;
 350         case 'F': return float.class;
 351         case 'D': return double.class;
 352         case 'L': return Object.class;
 353         case 'V': return void.class;
 354         default: assert false;
 355         }
 356         return null;
 357     }
 358     static MethodType signatureType(String sig) {
 359         Class<?>[] ptypes = new Class<?>[signatureArity(sig)];
 360         for (int i = 0; i < ptypes.length; i++)
 361             ptypes[i] = typeClass(sig.charAt(i));
 362         Class<?> rtype = typeClass(signatureReturn(sig));
 363         return MethodType.methodType(rtype, ptypes);
 364     }
 365 
 366     /*
 367      * Code generation issues:
 368      *
 369      * Compiled LFs should be reusable in general.
 370      * The biggest issue is how to decide when to pull a name into
 371      * the bytecode, versus loading a reified form from the MH data.
 372      *
 373      * For example, an asType wrapper may require execution of a cast
 374      * after a call to a MH.  The target type of the cast can be placed
 375      * as a constant in the LF itself.  This will force the cast type
 376      * to be compiled into the bytecodes and native code for the MH.
 377      * Or, the target type of the cast can be erased in the LF, and
 378      * loaded from the MH data.  (Later on, if the MH as a whole is
 379      * inlined, the data will flow into the inlined instance of the LF,
 380      * as a constant, and the end result will be an optimal cast.)
 381      *
 382      * This erasure of cast types can be done with any use of


 526         LambdaForm prep =  mtype.form().cachedLambdaForm(MethodTypeForm.LF_INTERPRET);
 527         if (prep != null)  return prep;
 528         assert(isValidSignature(sig));
 529         prep = new LambdaForm(sig);
 530         prep.vmentry = InvokerBytecodeGenerator.generateLambdaFormInterpreterEntryPoint(sig);
 531         //LambdaForm prep2 = PREPARED_FORMS.putIfAbsent(sig.intern(), prep);
 532         return mtype.form().setCachedLambdaForm(MethodTypeForm.LF_INTERPRET, prep);
 533     }
 534 
 535     // The next few routines are called only from assert expressions
 536     // They verify that the built-in invokers process the correct raw data types.
 537     private static boolean argumentTypesMatch(String sig, Object[] av) {
 538         int arity = signatureArity(sig);
 539         assert(av.length == arity) : "av.length == arity: av.length=" + av.length + ", arity=" + arity;
 540         assert(av[0] instanceof MethodHandle) : "av[0] not instace of MethodHandle: " + av[0];
 541         MethodHandle mh = (MethodHandle) av[0];
 542         MethodType mt = mh.type();
 543         assert(mt.parameterCount() == arity-1);
 544         for (int i = 0; i < av.length; i++) {
 545             Class<?> pt = (i == 0 ? MethodHandle.class : mt.parameterType(i-1));
 546             assert(valueMatches(sig.charAt(i), pt, av[i]));
 547         }
 548         return true;
 549     }
 550     private static boolean valueMatches(char tc, Class<?> type, Object x) {
 551         // The following line is needed because (...)void method handles can use non-void invokers
 552         if (type == void.class)  tc = 'V';   // can drop any kind of value
 553         assert tc == basicType(type) : tc + " == basicType(" + type + ")=" + basicType(type);
 554         switch (tc) {
 555         case 'I': assert checkInt(type, x)   : "checkInt(" + type + "," + x +")";   break;
 556         case 'J': assert x instanceof Long   : "instanceof Long: " + x;             break;
 557         case 'F': assert x instanceof Float  : "instanceof Float: " + x;            break;
 558         case 'D': assert x instanceof Double : "instanceof Double: " + x;           break;
 559         case 'L': assert checkRef(type, x)   : "checkRef(" + type + "," + x + ")";  break;
 560         case 'V': break;  // allow anything here; will be dropped
 561         default:  assert(false);
 562         }
 563         return true;
 564     }
 565     private static boolean returnTypesMatch(String sig, Object[] av, Object res) {
 566         MethodHandle mh = (MethodHandle) av[0];
 567         return valueMatches(signatureReturn(sig), mh.type().returnType(), res);
 568     }
 569     private static boolean checkInt(Class<?> type, Object x) {
 570         assert(x instanceof Integer);
 571         if (type == int.class)  return true;
 572         Wrapper w = Wrapper.forBasicType(type);
 573         assert(w.isSubwordOrInt());
 574         Object x1 = Wrapper.INT.wrap(w.wrap(x));
 575         return x.equals(x1);
 576     }
 577     private static boolean checkRef(Class<?> type, Object x) {
 578         assert(!type.isPrimitive());
 579         if (x == null)  return true;
 580         if (type.isInterface())  return true;


 719                 if (i+1 < arity)  buf.append(",");
 720                 continue;
 721             }
 722             buf.append("=").append(n.exprString());
 723             buf.append(";");
 724         }
 725         buf.append(result < 0 ? "void" : names[result]).append("}");
 726         if (TRACE_INTERPRETER) {
 727             // Extra verbosity:
 728             buf.append(":").append(basicTypeSignature());
 729             buf.append("/").append(vmentry);
 730         }
 731         return buf.toString();
 732     }
 733 
 734     /**
 735      * Apply immediate binding for a Name in this form indicated by its position relative to the form.
 736      * The first parameter to a LambdaForm, a0:L, always represents the form's method handle, so 0 is not
 737      * accepted as valid.
 738      */
 739     LambdaForm bindImmediate(int pos, char basicType, Object value) {
 740         // must be an argument, and the types must match
 741         assert pos > 0 && pos < arity && names[pos].type == basicType && Name.typesMatch(basicType, value);
 742 
 743         int arity2 = arity - 1;
 744         Name[] names2 = new Name[names.length - 1];
 745         for (int r = 0, w = 0; r < names.length; ++r, ++w) { // (r)ead from names, (w)rite to names2
 746             Name n = names[r];
 747             if (n.isParam()) {
 748                 if (n.index == pos) {
 749                     // do not copy over the argument that is to be replaced with a literal,
 750                     // but adjust the write index
 751                     --w;
 752                 } else {
 753                     names2[w] = new Name(w, n.type);
 754                 }
 755             } else {
 756                 Object[] arguments2 = new Object[n.arguments.length];
 757                 for (int i = 0; i < n.arguments.length; ++i) {
 758                     Object arg = n.arguments[i];
 759                     if (arg instanceof Name) {


 765                             arguments2[i] = names2[ni];
 766                         } else {
 767                             // replacement position passed
 768                             arguments2[i] = names2[ni - 1];
 769                         }
 770                     } else {
 771                         arguments2[i] = arg;
 772                     }
 773                 }
 774                 names2[w] = new Name(n.function, arguments2);
 775                 names2[w].initIndex(w);
 776             }
 777         }
 778 
 779         int result2 = result == -1 ? -1 : result - 1;
 780         return new LambdaForm(debugName, arity2, names2, result2);
 781     }
 782 
 783     LambdaForm bind(int namePos, BoundMethodHandle.SpeciesData oldData) {
 784         Name name = names[namePos];
 785         BoundMethodHandle.SpeciesData newData = oldData.extendWithType(name.type);
 786         return bind(name, newData.getterName(names[0], oldData.fieldCount()), oldData, newData);
 787     }
 788     LambdaForm bind(Name name, Name binding,
 789                     BoundMethodHandle.SpeciesData oldData,
 790                     BoundMethodHandle.SpeciesData newData) {
 791         int pos = name.index;
 792         assert(name.isParam());
 793         assert(!binding.isParam());
 794         assert(name.type == binding.type);
 795         assert(0 <= pos && pos < arity && names[pos] == name);
 796         assert(binding.function.memberDeclaringClassOrNull() == newData.clazz);
 797         assert(oldData.getters.length == newData.getters.length-1);
 798         if (bindCache != null) {
 799             LambdaForm form = bindCache[pos];
 800             if (form != null) {
 801                 assert(form.contains(binding)) : "form << " + form + " >> does not contain binding << " + binding + " >>";
 802                 return form;
 803             }
 804         } else {
 805             bindCache = new LambdaForm[arity];
 806         }


 857         if (result2 == pos)
 858             result2 = insPos;
 859         else if (result2 > pos && result2 <= insPos)
 860             result2 -= 1;
 861 
 862         return bindCache[pos] = new LambdaForm(debugName, arity2, names2, result2);
 863     }
 864 
 865     boolean contains(Name name) {
 866         int pos = name.index();
 867         if (pos >= 0) {
 868             return pos < names.length && name.equals(names[pos]);
 869         }
 870         for (int i = arity; i < names.length; i++) {
 871             if (name.equals(names[i]))
 872                 return true;
 873         }
 874         return false;
 875     }
 876 
 877     LambdaForm addArguments(int pos, char... types) {
 878         assert(pos <= arity);
 879         int length = names.length;
 880         int inTypes = types.length;
 881         Name[] names2 = Arrays.copyOf(names, length + inTypes);
 882         int arity2 = arity + inTypes;
 883         int result2 = result;
 884         if (result2 >= arity)
 885             result2 += inTypes;
 886         // names array has MH in slot 0; skip it.
 887         int argpos = pos + 1;
 888         // Note:  The LF constructor will rename names2[argpos...].
 889         // Make space for new arguments (shift temporaries).
 890         System.arraycopy(names, argpos, names2, argpos + inTypes, length - argpos);
 891         for (int i = 0; i < inTypes; i++) {
 892             names2[argpos + i] = new Name(types[i]);
 893         }
 894         return new LambdaForm(debugName, arity2, names2, result2);
 895     }
 896 
 897     LambdaForm addArguments(int pos, List<Class<?>> types) {
 898         char[] basicTypes = new char[types.size()];
 899         for (int i = 0; i < basicTypes.length; i++)
 900             basicTypes[i] = basicType(types.get(i));
 901         return addArguments(pos, basicTypes);
 902     }
 903 
 904     LambdaForm permuteArguments(int skip, int[] reorder, char[] types) {
 905         // Note:  When inArg = reorder[outArg], outArg is fed by a copy of inArg.
 906         // The types are the types of the new (incoming) arguments.
 907         int length = names.length;
 908         int inTypes = types.length;
 909         int outArgs = reorder.length;
 910         assert(skip+outArgs == arity);
 911         assert(permutedTypesMatch(reorder, types, names, skip));
 912         int pos = 0;
 913         // skip trivial first part of reordering:
 914         while (pos < outArgs && reorder[pos] == pos)  pos += 1;
 915         Name[] names2 = new Name[length - outArgs + inTypes];
 916         System.arraycopy(names, 0, names2, 0, skip+pos);
 917         // copy the body:
 918         int bodyLength = length - arity;
 919         System.arraycopy(names, skip+outArgs, names2, skip+inTypes, bodyLength);
 920         int arity2 = names2.length - bodyLength;
 921         int result2 = result;
 922         if (result2 >= 0) {
 923             if (result2 < skip+outArgs) {
 924                 // return the corresponding inArg


 943         }
 944         // some names are unused, but must be filled in
 945         for (int i = skip+pos; i < arity2; i++) {
 946             if (names2[i] == null)
 947                 names2[i] = argument(i, types[i - skip]);
 948         }
 949         for (int j = arity; j < names.length; j++) {
 950             int i = j - arity + arity2;
 951             // replace names2[i] by names[j]
 952             Name n = names[j];
 953             Name n2 = names2[i];
 954             if (n != n2) {
 955                 for (int k = i+1; k < names2.length; k++) {
 956                     names2[k] = names2[k].replaceName(n, n2);
 957                 }
 958             }
 959         }
 960         return new LambdaForm(debugName, arity2, names2, result2);
 961     }
 962 
 963     static boolean permutedTypesMatch(int[] reorder, char[] types, Name[] names, int skip) {
 964         int inTypes = types.length;
 965         int outArgs = reorder.length;
 966         for (int i = 0; i < outArgs; i++) {
 967             assert(names[skip+i].isParam());
 968             assert(names[skip+i].type == types[reorder[i]]);
 969         }
 970         return true;
 971     }
 972 
 973     static class NamedFunction {
 974         final MemberName member;
 975         @Stable MethodHandle resolvedHandle;
 976         @Stable MethodHandle invoker;
 977 
 978         NamedFunction(MethodHandle resolvedHandle) {
 979             this(resolvedHandle.internalMemberName(), resolvedHandle);
 980         }
 981         NamedFunction(MemberName member, MethodHandle resolvedHandle) {
 982             this.member = member;
 983             //resolvedHandle = eraseSubwordTypes(resolvedHandle);


1027             return this.member != null && this.member.equals(that.member);
1028         }
1029 
1030         @Override
1031         public int hashCode() {
1032             if (member != null)
1033                 return member.hashCode();
1034             return super.hashCode();
1035         }
1036 
1037         // Put the predefined NamedFunction invokers into the table.
1038         static void initializeInvokers() {
1039             for (MemberName m : MemberName.getFactory().getMethods(NamedFunction.class, false, null, null, null)) {
1040                 if (!m.isStatic() || !m.isPackage())  continue;
1041                 MethodType type = m.getMethodType();
1042                 if (type.equals(INVOKER_METHOD_TYPE) &&
1043                     m.getName().startsWith("invoke_")) {
1044                     String sig = m.getName().substring("invoke_".length());
1045                     int arity = LambdaForm.signatureArity(sig);
1046                     MethodType srcType = MethodType.genericMethodType(arity);
1047                     if (LambdaForm.signatureReturn(sig) == 'V')
1048                         srcType = srcType.changeReturnType(void.class);
1049                     MethodTypeForm typeForm = srcType.form();
1050                     typeForm.namedFunctionInvoker = DirectMethodHandle.make(m);
1051                 }
1052             }
1053         }
1054 
1055         // The following are predefined NamedFunction invokers.  The system must build
1056         // a separate invoker for each distinct signature.
1057         /** void return type invokers. */
1058         @Hidden
1059         static Object invoke__V(MethodHandle mh, Object[] a) throws Throwable {
1060             assert(a.length == 0);
1061             mh.invokeBasic();
1062             return null;
1063         }
1064         @Hidden
1065         static Object invoke_L_V(MethodHandle mh, Object[] a) throws Throwable {
1066             assert(a.length == 1);
1067             mh.invokeBasic(a[0]);


1117             assert(a.length == 4);
1118             return mh.invokeBasic(a[0], a[1], a[2], a[3]);
1119         }
1120         @Hidden
1121         static Object invoke_LLLLL_L(MethodHandle mh, Object[] a) throws Throwable {
1122             assert(a.length == 5);
1123             return mh.invokeBasic(a[0], a[1], a[2], a[3], a[4]);
1124         }
1125 
1126         static final MethodType INVOKER_METHOD_TYPE =
1127             MethodType.methodType(Object.class, MethodHandle.class, Object[].class);
1128 
1129         private static MethodHandle computeInvoker(MethodTypeForm typeForm) {
1130             MethodHandle mh = typeForm.namedFunctionInvoker;
1131             if (mh != null)  return mh;
1132             MemberName invoker = InvokerBytecodeGenerator.generateNamedFunctionInvoker(typeForm);  // this could take a while
1133             mh = DirectMethodHandle.make(invoker);
1134             MethodHandle mh2 = typeForm.namedFunctionInvoker;
1135             if (mh2 != null)  return mh2;  // benign race
1136             if (!mh.type().equals(INVOKER_METHOD_TYPE))
1137                 throw new InternalError(mh.debugString());
1138             return typeForm.namedFunctionInvoker = mh;
1139         }
1140 
1141         @Hidden
1142         Object invokeWithArguments(Object... arguments) throws Throwable {
1143             // If we have a cached invoker, call it right away.
1144             // NOTE: The invoker always returns a reference value.
1145             if (TRACE_INTERPRETER)  return invokeWithArgumentsTracing(arguments);
1146             assert(checkArgumentTypes(arguments, methodType()));
1147             return invoker().invokeBasic(resolvedHandle(), arguments);
1148         }
1149 
1150         @Hidden
1151         Object invokeWithArgumentsTracing(Object[] arguments) throws Throwable {
1152             Object rval;
1153             try {
1154                 traceInterpreter("[ call", this, arguments);
1155                 if (invoker == null) {
1156                     traceInterpreter("| getInvoker", this);
1157                     invoker();


1207         }
1208 
1209         MemberName member() {
1210             assert(assertMemberIsConsistent());
1211             return member;
1212         }
1213 
1214         // Called only from assert.
1215         private boolean assertMemberIsConsistent() {
1216             if (resolvedHandle instanceof DirectMethodHandle) {
1217                 MemberName m = resolvedHandle.internalMemberName();
1218                 assert(m.equals(member));
1219             }
1220             return true;
1221         }
1222 
1223         Class<?> memberDeclaringClassOrNull() {
1224             return (member == null) ? null : member.getDeclaringClass();
1225         }
1226 
1227         char returnType() {
1228             return basicType(methodType().returnType());
1229         }
1230 
1231         char parameterType(int n) {
1232             return basicType(methodType().parameterType(n));
1233         }
1234 
1235         int arity() {
1236             //int siglen = member.getMethodType().parameterCount();
1237             //if (!member.isStatic())  siglen += 1;
1238             //return siglen;
1239             return methodType().parameterCount();
1240         }
1241 
1242         public String toString() {
1243             if (member == null)  return String.valueOf(resolvedHandle);
1244             return member.getDeclaringClass().getSimpleName()+"."+member.getName();
1245         }
1246     }
1247 
1248     void resolve() {
1249         for (Name n : names) n.resolve();
1250     }
1251 
1252     public static char basicType(Class<?> type) {
1253         char c = Wrapper.basicTypeChar(type);
1254         if ("ZBSC".indexOf(c) >= 0)  c = 'I';
1255         assert("LIJFDV".indexOf(c) >= 0);
1256         return c;
1257     }
1258     public static char[] basicTypes(List<Class<?>> types) {
1259         char[] btypes = new char[types.size()];
1260         for (int i = 0; i < btypes.length; i++) {
1261             btypes[i] = basicType(types.get(i));
1262         }
1263         return btypes;


1264     }

1265     public static String basicTypeSignature(MethodType type) {
1266         char[] sig = new char[type.parameterCount() + 2];
1267         int sigp = 0;
1268         for (Class<?> pt : type.parameterList()) {
1269             sig[sigp++] = basicType(pt);
1270         }
1271         sig[sigp++] = '_';
1272         sig[sigp++] = basicType(type.returnType());
1273         assert(sigp == sig.length);
1274         return String.valueOf(sig);
1275     }




























1276 
1277     static final class Name {
1278         final char type;
1279         private short index;
1280         final NamedFunction function;
1281         @Stable final Object[] arguments;
1282 
1283         private Name(int index, char type, NamedFunction function, Object[] arguments) {
1284             this.index = (short)index;
1285             this.type = type;
1286             this.function = function;
1287             this.arguments = arguments;
1288             assert(this.index == index);
1289         }
1290         Name(MethodHandle function, Object... arguments) {
1291             this(new NamedFunction(function), arguments);
1292         }
1293         Name(MethodType functionType, Object... arguments) {
1294             this(new NamedFunction(functionType), arguments);
1295             assert(arguments[0] instanceof Name && ((Name)arguments[0]).type == 'L');
1296         }
1297         Name(MemberName function, Object... arguments) {
1298             this(new NamedFunction(function), arguments);
1299         }
1300         Name(NamedFunction function, Object... arguments) {
1301             this(-1, function.returnType(), function, arguments = arguments.clone());
1302             assert(arguments.length == function.arity()) : "arity mismatch: arguments.length=" + arguments.length + " == function.arity()=" + function.arity() + " in " + debugString();
1303             for (int i = 0; i < arguments.length; i++)
1304                 assert(typesMatch(function.parameterType(i), arguments[i])) : "types don't match: function.parameterType(" + i + ")=" + function.parameterType(i) + ", arguments[" + i + "]=" + arguments[i] + " in " + debugString();
1305         }
1306         Name(int index, char type) {

1307             this(index, type, null, null);
1308         }
1309         Name(char type) {
1310             this(-1, type);
1311         }
1312 
1313         char type() { return type; }
1314         int index() { return index; }
1315         boolean initIndex(int i) {
1316             if (index != i) {
1317                 if (index != -1)  return false;
1318                 index = (short)i;
1319             }
1320             return true;
1321         }
1322 


1323 
1324         void resolve() {
1325             if (function != null)
1326                 function.resolve();
1327         }
1328 
1329         Name newIndex(int i) {
1330             if (initIndex(i))  return this;
1331             return cloneWithIndex(i);
1332         }
1333         Name cloneWithIndex(int i) {
1334             Object[] newArguments = (arguments == null) ? null : arguments.clone();
1335             return new Name(i, type, function, newArguments);
1336         }
1337         Name replaceName(Name oldName, Name newName) {  // FIXME: use replaceNames uniformly
1338             if (oldName == newName)  return this;
1339             @SuppressWarnings("LocalVariableHidesMemberVariable")
1340             Object[] arguments = this.arguments;
1341             if (arguments == null)  return this;
1342             boolean replaced = false;


1380                 }
1381             }
1382             if (!replaced)  return this;
1383             return new Name(function, arguments);
1384         }
1385         void internArguments() {
1386             @SuppressWarnings("LocalVariableHidesMemberVariable")
1387             Object[] arguments = this.arguments;
1388             for (int j = 0; j < arguments.length; j++) {
1389                 if (arguments[j] instanceof Name) {
1390                     Name n = (Name) arguments[j];
1391                     if (n.isParam() && n.index < INTERNED_ARGUMENT_LIMIT)
1392                         arguments[j] = internArgument(n);
1393                 }
1394             }
1395         }
1396         boolean isParam() {
1397             return function == null;
1398         }
1399         boolean isConstantZero() {
1400             return !isParam() && arguments.length == 0 && function.equals(constantZero(0, type).function);
1401         }
1402 
1403         public String toString() {
1404             return (isParam()?"a":"t")+(index >= 0 ? index : System.identityHashCode(this))+":"+type;
1405         }
1406         public String debugString() {
1407             String s = toString();
1408             return (function == null) ? s : s + "=" + exprString();
1409         }
1410         public String exprString() {
1411             if (function == null)  return "null";
1412             StringBuilder buf = new StringBuilder(function.toString());
1413             buf.append("(");
1414             String cma = "";
1415             for (Object a : arguments) {
1416                 buf.append(cma); cma = ",";
1417                 if (a instanceof Name || a instanceof Integer)
1418                     buf.append(a);
1419                 else
1420                     buf.append("(").append(a).append(")");
1421             }
1422             buf.append(")");
1423             return buf.toString();
1424         }
1425 
1426         private static boolean typesMatch(char parameterType, Object object) {
1427             if (object instanceof Name) {
1428                 return ((Name)object).type == parameterType;
1429             }
1430             switch (parameterType) {
1431                 case 'I':  return object instanceof Integer;
1432                 case 'J':  return object instanceof Long;
1433                 case 'F':  return object instanceof Float;
1434                 case 'D':  return object instanceof Double;
1435             }
1436             assert(parameterType == 'L');
1437             return true;
1438         }
1439 
1440         /**
1441          * Does this Name precede the given binding node in some canonical order?
1442          * This predicate is used to order data bindings (via insertion sort)
1443          * with some stability.
1444          */
1445         boolean isSiblingBindingBefore(Name binding) {
1446             assert(!binding.isParam());
1447             if (isParam())  return true;
1448             if (function.equals(binding.function) &&
1449                 arguments.length == binding.arguments.length) {
1450                 boolean sawInt = false;
1451                 for (int i = 0; i < arguments.length; i++) {
1452                     Object a1 = arguments[i];
1453                     Object a2 = binding.arguments[i];
1454                     if (!a1.equals(a2)) {
1455                         if (a1 instanceof Integer && a2 instanceof Integer) {
1456                             if (sawInt)  continue;


1493         }
1494 
1495         public boolean equals(Name that) {
1496             if (this == that)  return true;
1497             if (isParam())
1498                 // each parameter is a unique atom
1499                 return false;  // this != that
1500             return
1501                 //this.index == that.index &&
1502                 this.type == that.type &&
1503                 this.function.equals(that.function) &&
1504                 Arrays.equals(this.arguments, that.arguments);
1505         }
1506         @Override
1507         public boolean equals(Object x) {
1508             return x instanceof Name && equals((Name)x);
1509         }
1510         @Override
1511         public int hashCode() {
1512             if (isParam())
1513                 return index | (type << 8);
1514             return function.hashCode() ^ Arrays.hashCode(arguments);
1515         }
1516     }
1517 
1518     /** Return the index of the last name which contains n as an argument.
1519      *  Return -1 if the name is not used.  Return names.length if it is the return value.
1520      */
1521     int lastUseIndex(Name n) {
1522         int ni = n.index, nmax = names.length;
1523         assert(names[ni] == n);
1524         if (result == ni)  return nmax;  // live all the way beyond the end
1525         for (int i = nmax; --i > ni; ) {
1526             if (names[i].lastUseIndex(n) >= 0)
1527                 return i;
1528         }
1529         return -1;
1530     }
1531 
1532     /** Return the number of times n is used as an argument or return value. */
1533     int useCount(Name n) {
1534         int ni = n.index, nmax = names.length;
1535         int end = lastUseIndex(n);
1536         if (end < 0)  return 0;
1537         int count = 0;
1538         if (end == nmax) { count++; end--; }
1539         int beg = n.index() + 1;
1540         if (beg < arity)  beg = arity;
1541         for (int i = beg; i <= end; i++) {
1542             count += names[i].useCount(n);
1543         }
1544         return count;
1545     }
1546 
1547     static Name argument(int which, char type) {
1548         int tn = ALL_TYPES.indexOf(type);
1549         if (tn < 0 || which >= INTERNED_ARGUMENT_LIMIT)


1550             return new Name(which, type);
1551         return INTERNED_ARGUMENTS[tn][which];
1552     }
1553     static Name internArgument(Name n) {
1554         assert(n.isParam()) : "not param: " + n;
1555         assert(n.index < INTERNED_ARGUMENT_LIMIT);
1556         return argument(n.index, n.type);
1557     }
1558     static Name[] arguments(int extra, String types) {
1559         int length = types.length();
1560         Name[] names = new Name[length + extra];
1561         for (int i = 0; i < length; i++)
1562             names[i] = argument(i, types.charAt(i));
1563         return names;
1564     }
1565     static Name[] arguments(int extra, char... types) {
1566         int length = types.length;
1567         Name[] names = new Name[length + extra];
1568         for (int i = 0; i < length; i++)
1569             names[i] = argument(i, types[i]);
1570         return names;
1571     }


1573         int length = types.size();
1574         Name[] names = new Name[length + extra];
1575         for (int i = 0; i < length; i++)
1576             names[i] = argument(i, basicType(types.get(i)));
1577         return names;
1578     }
1579     static Name[] arguments(int extra, Class<?>... types) {
1580         int length = types.length;
1581         Name[] names = new Name[length + extra];
1582         for (int i = 0; i < length; i++)
1583             names[i] = argument(i, basicType(types[i]));
1584         return names;
1585     }
1586     static Name[] arguments(int extra, MethodType types) {
1587         int length = types.parameterCount();
1588         Name[] names = new Name[length + extra];
1589         for (int i = 0; i < length; i++)
1590             names[i] = argument(i, basicType(types.parameterType(i)));
1591         return names;
1592     }
1593     static final String ALL_TYPES = "LIJFD";  // omit V, not an argument type
1594     static final int INTERNED_ARGUMENT_LIMIT = 10;
1595     private static final Name[][] INTERNED_ARGUMENTS
1596             = new Name[ALL_TYPES.length()][INTERNED_ARGUMENT_LIMIT];
1597     static {
1598         for (int tn = 0; tn < ALL_TYPES.length(); tn++) {
1599             for (int i = 0; i < INTERNED_ARGUMENTS[tn].length; i++) {
1600                 char type = ALL_TYPES.charAt(tn);
1601                 INTERNED_ARGUMENTS[tn][i] = new Name(i, type);
1602             }
1603         }
1604     }
1605 
1606     private static final MemberName.Factory IMPL_NAMES = MemberName.getFactory();
1607 
1608     static Name constantZero(int which, char type) {
1609         return CONSTANT_ZERO[ALL_TYPES.indexOf(type)].newIndex(which);
1610     }
1611     private static final Name[] CONSTANT_ZERO
1612             = new Name[ALL_TYPES.length()];
1613     static {
1614         for (int tn = 0; tn < ALL_TYPES.length(); tn++) {
1615             char bt = ALL_TYPES.charAt(tn);
1616             Wrapper wrap = Wrapper.forBasicType(bt);
1617             MemberName zmem = new MemberName(LambdaForm.class, "zero"+bt, MethodType.methodType(wrap.primitiveType()), REF_invokeStatic);




















1618             try {
1619                 zmem = IMPL_NAMES.resolveOrFail(REF_invokeStatic, zmem, null, NoSuchMethodException.class);

1620             } catch (IllegalAccessException|NoSuchMethodException ex) {
1621                 throw newInternalError(ex);
1622             }
1623             NamedFunction zcon = new NamedFunction(zmem);
1624             Name n = new Name(zcon).newIndex(0);
1625             assert(n.type == ALL_TYPES.charAt(tn));
1626             CONSTANT_ZERO[tn] = n;
1627             assert(n.isConstantZero());











































1628         }
1629     }
1630 
1631     // Avoid appealing to ValueConversions at bootstrap time:
1632     private static int zeroI() { return 0; }
1633     private static long zeroJ() { return 0; }
1634     private static float zeroF() { return 0; }
1635     private static double zeroD() { return 0; }
1636     private static Object zeroL() { return null; }
1637 
1638     // Put this last, so that previous static inits can run before.
1639     static {
1640         if (USE_PREDEFINED_INTERPRET_METHODS)
1641             PREPARED_FORMS.putAll(computeInitialPreparedForms());
1642     }

1643 
1644     /**
1645      * Internal marker for byte-compiled LambdaForms.
1646      */
1647     /*non-public*/
1648     @Target(ElementType.METHOD)
1649     @Retention(RetentionPolicy.RUNTIME)
1650     @interface Compiled {
1651     }
1652 
1653     /**
1654      * Internal marker for LambdaForm interpreter frames.
1655      */
1656     /*non-public*/
1657     @Target(ElementType.METHOD)
1658     @Retention(RetentionPolicy.RUNTIME)
1659     @interface Hidden {
1660     }
1661 
1662 


1673         Object[] abc = { "a", "bc" };
1674         List<?> lst = (List<?>) MethodHandle.linkToStatic(abc, asList_MN);
1675         System.out.println("lst="+lst);
1676         MemberName toString_MN = new MemberName(Object.class.getMethod("toString"));
1677         String s1 = (String) MethodHandle.linkToVirtual(lst, toString_MN);
1678         toString_MN = new MemberName(Object.class.getMethod("toString"), true);
1679         String s2 = (String) MethodHandle.linkToSpecial(lst, toString_MN);
1680         System.out.println("[s1,s2,lst]="+Arrays.asList(s1, s2, lst.toString()));
1681         MemberName toArray_MN = new MemberName(List.class.getMethod("toArray"));
1682         Object[] arr = (Object[]) MethodHandle.linkToInterface(lst, toArray_MN);
1683         System.out.println("toArray="+Arrays.toString(arr));
1684     }
1685     static { try { testMethodHandleLinkers(); } catch (Throwable ex) { throw new RuntimeException(ex); } }
1686     // Requires these definitions in MethodHandle:
1687     static final native Object linkToStatic(Object x1, MemberName mn) throws Throwable;
1688     static final native Object linkToVirtual(Object x1, MemberName mn) throws Throwable;
1689     static final native Object linkToSpecial(Object x1, MemberName mn) throws Throwable;
1690     static final native Object linkToInterface(Object x1, MemberName mn) throws Throwable;
1691  */
1692 
1693     static { NamedFunction.initializeInvokers(); }














1694 
1695     // The following hack is necessary in order to suppress TRACE_INTERPRETER
1696     // during execution of the static initializes of this class.
1697     // Turning on TRACE_INTERPRETER too early will cause
1698     // stack overflows and other misbehavior during attempts to trace events
1699     // that occur during LambdaForm.<clinit>.
1700     // Therefore, do not move this line higher in this file, and do not remove.
1701     private static final boolean TRACE_INTERPRETER = MethodHandleStatics.TRACE_INTERPRETER;
1702 }


  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.lang.annotation.*;
  29 import java.lang.reflect.Method;
  30 import java.util.Map;
  31 import java.util.List;
  32 import java.util.Arrays;

  33 import java.util.HashMap;
  34 import java.util.concurrent.ConcurrentHashMap;
  35 import sun.invoke.util.Wrapper;
  36 import java.lang.reflect.Field;
  37 
  38 import static java.lang.invoke.LambdaForm.BasicType.*;
  39 import static java.lang.invoke.MethodHandleStatics.*;
  40 import static java.lang.invoke.MethodHandleNatives.Constants.*;


  41 
  42 /**
  43  * The symbolic, non-executable form of a method handle's invocation semantics.
  44  * It consists of a series of names.
  45  * The first N (N=arity) names are parameters,
  46  * while any remaining names are temporary values.
  47  * Each temporary specifies the application of a function to some arguments.
  48  * The functions are method handles, while the arguments are mixes of
  49  * constant values and local names.
  50  * The result of the lambda is defined as one of the names, often the last one.
  51  * <p>
  52  * Here is an approximate grammar:
  53  * <blockquote><pre>{@code
  54  * LambdaForm = "(" ArgName* ")=>{" TempName* Result "}"
  55  * ArgName = "a" N ":" T
  56  * TempName = "t" N ":" T "=" Function "(" Argument* ");"
  57  * Function = ConstantValue
  58  * Argument = NameRef | ConstantValue
  59  * Result = NameRef | "void"
  60  * NameRef = "a" N | "t" N


 113  * (a0:L, a1:L)=>{ t2:L = BoundMethodHandle#argument(a0);
 114  *                 t3:L = Class#cast(t2,a1); t3 }
 115  *     == invoker for identity method handle which performs cast
 116  * }</pre></blockquote>
 117  * <p>
 118  * @author John Rose, JSR 292 EG
 119  */
 120 class LambdaForm {
 121     final int arity;
 122     final int result;
 123     @Stable final Name[] names;
 124     final String debugName;
 125     MemberName vmentry;   // low-level behavior, or null if not yet prepared
 126     private boolean isCompiled;
 127 
 128     // Caches for common structural transforms:
 129     LambdaForm[] bindCache;
 130 
 131     public static final int VOID_RESULT = -1, LAST_RESULT = -2;
 132 
 133     enum BasicType {
 134         L_TYPE('L', Object.class, Wrapper.OBJECT),  // all reference types
 135         I_TYPE('I', int.class,    Wrapper.INT),
 136         J_TYPE('J', long.class,   Wrapper.LONG),
 137         F_TYPE('F', float.class,  Wrapper.FLOAT),
 138         D_TYPE('D', double.class, Wrapper.DOUBLE),  // all primitive types
 139         V_TYPE('V', void.class,   Wrapper.VOID);    // not valid in all contexts
 140 
 141         static final BasicType[] ALL_TYPES = { L_TYPE, I_TYPE, J_TYPE, F_TYPE, D_TYPE, V_TYPE };
 142         static final BasicType[] ARG_TYPES = { L_TYPE, I_TYPE, J_TYPE, F_TYPE, D_TYPE };
 143 
 144         static final int ARG_TYPE_LIMIT = V_TYPE.ordinal();
 145         static final int TYPE_LIMIT = ARG_TYPE_LIMIT+1;
 146 
 147         private final char btChar;
 148         private final Class<?> btClass;
 149         private final Wrapper btWrapper;
 150 
 151         private BasicType(char btChar, Class<?> btClass, Wrapper wrapper) {
 152             this.btChar = btChar;
 153             this.btClass = btClass;
 154             this.btWrapper = wrapper;
 155         }
 156 
 157         char basicTypeChar() {
 158             return btChar;
 159         }
 160         Class<?> basicTypeClass() {
 161             return btClass;
 162         }
 163         Wrapper basicTypeWrapper() {
 164             return btWrapper;
 165         }
 166         int basicTypeSlots() {
 167             return btWrapper.stackSlots();
 168         }
 169 
 170         static BasicType basicType(byte type) {
 171             return ALL_TYPES[type];
 172         }
 173         static BasicType basicType(char type) {
 174             switch (type) {
 175                 case 'L': return L_TYPE;
 176                 case 'I': return I_TYPE;
 177                 case 'J': return J_TYPE;
 178                 case 'F': return F_TYPE;
 179                 case 'D': return D_TYPE;
 180                 case 'V': return V_TYPE;
 181                 // all subword types are represented as ints
 182                 case 'Z':
 183                 case 'B':
 184                 case 'S':
 185                 case 'C':
 186                     return I_TYPE;
 187                 default:
 188                     throw newInternalError("Unknown type char: '"+type+"'");
 189             }
 190         }
 191         static BasicType basicType(Wrapper type) {
 192             char c = type.basicTypeChar();
 193             return basicType(c);
 194         }
 195         static BasicType basicType(Class<?> type) {
 196             if (!type.isPrimitive())  return L_TYPE;
 197             return basicType(Wrapper.forPrimitiveType(type));
 198         }
 199 
 200         static char basicTypeChar(Class<?> type) {
 201             return basicType(type).btChar;
 202         }
 203         static BasicType[] basicTypes(List<Class<?>> types) {
 204             BasicType[] btypes = new BasicType[types.size()];
 205             for (int i = 0; i < btypes.length; i++) {
 206                 btypes[i] = basicType(types.get(i));
 207             }
 208             return btypes;
 209         }
 210         static BasicType[] basicTypes(String types) {
 211             BasicType[] btypes = new BasicType[types.length()];
 212             for (int i = 0; i < btypes.length; i++) {
 213                 btypes[i] = basicType(types.charAt(i));
 214             }
 215             return btypes;
 216         }
 217         static boolean isBasicTypeChar(char c) {
 218             return "LIJFDV".indexOf(c) >= 0;
 219         }
 220         static boolean isArgBasicTypeChar(char c) {
 221             return "LIJFD".indexOf(c) >= 0;
 222         }
 223     }
 224 
 225     LambdaForm(String debugName,
 226                int arity, Name[] names, int result) {
 227         assert(namesOK(arity, names));
 228         this.arity = arity;
 229         this.result = fixResult(result, names);
 230         this.names = names.clone();
 231         this.debugName = fixDebugName(debugName);
 232         normalize();
 233     }
 234 
 235     LambdaForm(String debugName,
 236                int arity, Name[] names) {
 237         this(debugName,
 238              arity, names, LAST_RESULT);
 239     }
 240 
 241     LambdaForm(String debugName,
 242                Name[] formals, Name[] temps, Name result) {
 243         this(debugName,
 244              formals.length, buildNames(formals, temps, result), LAST_RESULT);
 245     }
 246 
 247     private static Name[] buildNames(Name[] formals, Name[] temps, Name result) {
 248         int arity = formals.length;
 249         int length = arity + temps.length + (result == null ? 0 : 1);
 250         Name[] names = Arrays.copyOf(formals, length);
 251         System.arraycopy(temps, 0, names, arity, temps.length);
 252         if (result != null)
 253             names[length - 1] = result;
 254         return names;
 255     }
 256 
 257     private LambdaForm(String sig) {
 258         // Make a blank lambda form, which returns a constant zero or null.
 259         // It is used as a template for managing the invocation of similar forms that are non-empty.
 260         // Called only from getPreparedForm.
 261         assert(isValidSignature(sig));
 262         this.arity = signatureArity(sig);
 263         this.result = (signatureReturn(sig) == V_TYPE ? -1 : arity);
 264         this.names = buildEmptyNames(arity, sig);
 265         this.debugName = "LF.zero";
 266         assert(nameRefsAreLegal());
 267         assert(isEmpty());
 268         assert(sig.equals(basicTypeSignature())) : sig + " != " + basicTypeSignature();
 269     }
 270 
 271     private static Name[] buildEmptyNames(int arity, String basicTypeSignature) {
 272         assert(isValidSignature(basicTypeSignature));
 273         int resultPos = arity + 1;  // skip '_'
 274         if (arity < 0 || basicTypeSignature.length() != resultPos+1)
 275             throw new IllegalArgumentException("bad arity for "+basicTypeSignature);
 276         int numRes = (basicType(basicTypeSignature.charAt(resultPos)) == V_TYPE ? 0 : 1);
 277         Name[] names = arguments(numRes, basicTypeSignature.substring(0, arity));
 278         for (int i = 0; i < numRes; i++) {
 279             Name zero = new Name(constantZero(basicType(basicTypeSignature.charAt(resultPos + i))));
 280             names[arity + i] = zero.newIndex(arity + i);
 281         }
 282         return names;
 283     }
 284 
 285     private static int fixResult(int result, Name[] names) {
 286         if (result == LAST_RESULT)
 287             result = names.length - 1;  // might still be void
 288         if (result >= 0 && names[result].type == V_TYPE)
 289             result = -1;


 290         return result;
 291     }
 292 
 293     private static String fixDebugName(String debugName) {
 294         if (DEBUG_NAME_COUNTERS != null) {
 295             int under = debugName.indexOf('_');
 296             int length = debugName.length();
 297             if (under < 0)  under = length;
 298             String debugNameStem = debugName.substring(0, under);
 299             Integer ctr;
 300             synchronized (DEBUG_NAME_COUNTERS) {
 301                 ctr = DEBUG_NAME_COUNTERS.get(debugNameStem);
 302                 if (ctr == null)  ctr = 0;
 303                 DEBUG_NAME_COUNTERS.put(debugNameStem, ctr+1);
 304             }
 305             StringBuilder buf = new StringBuilder(debugNameStem);
 306             buf.append('_');
 307             int leadingZero = buf.length();
 308             buf.append((int) ctr);
 309             for (int i = buf.length() - leadingZero; i < 3; i++)
 310                 buf.insert(leadingZero, '0');
 311             if (under < length) {
 312                 ++under;    // skip "_"
 313                 while (under < length && Character.isDigit(debugName.charAt(under))) {
 314                     ++under;
 315                 }
 316                 if (under < length && debugName.charAt(under) == '_')  ++under;
 317                 if (under < length)
 318                     buf.append('_').append(debugName, under, length);
 319             }
 320             return buf.toString();
 321         }
 322         return debugName;
 323     }
 324 
 325     private static boolean namesOK(int arity, Name[] names) {
 326         for (int i = 0; i < names.length; i++) {
 327             Name n = names[i];
 328             assert(n != null) : "n is null";
 329             if (i < arity)
 330                 assert( n.isParam()) : n + " is not param at " + i;
 331             else
 332                 assert(!n.isParam()) : n + " is param at " + i;
 333         }
 334         return true;
 335     }
 336 
 337     /** Renumber and/or replace params so that they are interned and canonically numbered. */
 338     private void normalize() {
 339         Name[] oldNames = null;
 340         int changesStart = 0;
 341         for (int i = 0; i < names.length; i++) {
 342             Name n = names[i];
 343             if (!n.initIndex(i)) {
 344                 if (oldNames == null) {


 400             for (Object arg : n.arguments) {
 401                 if (arg instanceof Name) {
 402                     Name n2 = (Name) arg;
 403                     int i2 = n2.index;
 404                     assert(0 <= i2 && i2 < names.length) : n.debugString() + ": 0 <= i2 && i2 < names.length: 0 <= " + i2 + " < " + names.length;
 405                     assert(names[i2] == n2) : Arrays.asList("-1-", i, "-2-", n.debugString(), "-3-", i2, "-4-", n2.debugString(), "-5-", names[i2].debugString(), "-6-", this);
 406                     assert(i2 < i);  // ref must come after def!
 407                 }
 408             }
 409         }
 410         return true;
 411     }
 412 
 413     /** Invoke this form on the given arguments. */
 414     // final Object invoke(Object... args) throws Throwable {
 415     //     // NYI: fit this into the fast path?
 416     //     return interpretWithArguments(args);
 417     // }
 418 
 419     /** Report the return type. */
 420     BasicType returnType() {
 421         if (result < 0)  return V_TYPE;
 422         Name n = names[result];
 423         return n.type;
 424     }
 425 
 426     /** Report the N-th argument type. */
 427     BasicType parameterType(int n) {
 428         assert(n < arity);
 429         return names[n].type;
 430     }
 431 
 432     /** Report the arity. */
 433     int arity() {
 434         return arity;
 435     }
 436 
 437     /** Return the method type corresponding to my basic type signature. */
 438     MethodType methodType() {
 439         return signatureType(basicTypeSignature());
 440     }
 441     /** Return ABC_Z, where the ABC are parameter type characters, and Z is the return type character. */
 442     final String basicTypeSignature() {
 443         StringBuilder buf = new StringBuilder(arity() + 3);
 444         for (int i = 0, a = arity(); i < a; i++)
 445             buf.append(parameterType(i).basicTypeChar());
 446         return buf.append('_').append(returnType().basicTypeChar()).toString();
 447     }
 448     static int signatureArity(String sig) {
 449         assert(isValidSignature(sig));
 450         return sig.indexOf('_');
 451     }
 452     static BasicType signatureReturn(String sig) {
 453         return basicType(sig.charAt(signatureArity(sig)+1));
 454     }
 455     static boolean isValidSignature(String sig) {
 456         int arity = sig.indexOf('_');
 457         if (arity < 0)  return false;  // must be of the form *_*
 458         int siglen = sig.length();
 459         if (siglen != arity + 2)  return false;  // *_X
 460         for (int i = 0; i < siglen; i++) {
 461             if (i == arity)  continue;  // skip '_'
 462             char c = sig.charAt(i);
 463             if (c == 'V')
 464                 return (i == siglen - 1 && arity == siglen - 2);
 465             if (!isArgBasicTypeChar(c))  return false; // must be [LIJFD]
 466         }
 467         return true;  // [LIJFD]*_[LIJFDV]
 468     }












 469     static MethodType signatureType(String sig) {
 470         Class<?>[] ptypes = new Class<?>[signatureArity(sig)];
 471         for (int i = 0; i < ptypes.length; i++)
 472             ptypes[i] = basicType(sig.charAt(i)).btClass;
 473         Class<?> rtype = signatureReturn(sig).btClass;
 474         return MethodType.methodType(rtype, ptypes);
 475     }
 476 
 477     /*
 478      * Code generation issues:
 479      *
 480      * Compiled LFs should be reusable in general.
 481      * The biggest issue is how to decide when to pull a name into
 482      * the bytecode, versus loading a reified form from the MH data.
 483      *
 484      * For example, an asType wrapper may require execution of a cast
 485      * after a call to a MH.  The target type of the cast can be placed
 486      * as a constant in the LF itself.  This will force the cast type
 487      * to be compiled into the bytecodes and native code for the MH.
 488      * Or, the target type of the cast can be erased in the LF, and
 489      * loaded from the MH data.  (Later on, if the MH as a whole is
 490      * inlined, the data will flow into the inlined instance of the LF,
 491      * as a constant, and the end result will be an optimal cast.)
 492      *
 493      * This erasure of cast types can be done with any use of


 637         LambdaForm prep =  mtype.form().cachedLambdaForm(MethodTypeForm.LF_INTERPRET);
 638         if (prep != null)  return prep;
 639         assert(isValidSignature(sig));
 640         prep = new LambdaForm(sig);
 641         prep.vmentry = InvokerBytecodeGenerator.generateLambdaFormInterpreterEntryPoint(sig);
 642         //LambdaForm prep2 = PREPARED_FORMS.putIfAbsent(sig.intern(), prep);
 643         return mtype.form().setCachedLambdaForm(MethodTypeForm.LF_INTERPRET, prep);
 644     }
 645 
 646     // The next few routines are called only from assert expressions
 647     // They verify that the built-in invokers process the correct raw data types.
 648     private static boolean argumentTypesMatch(String sig, Object[] av) {
 649         int arity = signatureArity(sig);
 650         assert(av.length == arity) : "av.length == arity: av.length=" + av.length + ", arity=" + arity;
 651         assert(av[0] instanceof MethodHandle) : "av[0] not instace of MethodHandle: " + av[0];
 652         MethodHandle mh = (MethodHandle) av[0];
 653         MethodType mt = mh.type();
 654         assert(mt.parameterCount() == arity-1);
 655         for (int i = 0; i < av.length; i++) {
 656             Class<?> pt = (i == 0 ? MethodHandle.class : mt.parameterType(i-1));
 657             assert(valueMatches(basicType(sig.charAt(i)), pt, av[i]));
 658         }
 659         return true;
 660     }
 661     private static boolean valueMatches(BasicType tc, Class<?> type, Object x) {
 662         // The following line is needed because (...)void method handles can use non-void invokers
 663         if (type == void.class)  tc = V_TYPE;   // can drop any kind of value
 664         assert tc == basicType(type) : tc + " == basicType(" + type + ")=" + basicType(type);
 665         switch (tc) {
 666         case I_TYPE: assert checkInt(type, x)   : "checkInt(" + type + "," + x +")";   break;
 667         case J_TYPE: assert x instanceof Long   : "instanceof Long: " + x;             break;
 668         case F_TYPE: assert x instanceof Float  : "instanceof Float: " + x;            break;
 669         case D_TYPE: assert x instanceof Double : "instanceof Double: " + x;           break;
 670         case L_TYPE: assert checkRef(type, x)   : "checkRef(" + type + "," + x + ")";  break;
 671         case V_TYPE: break;  // allow anything here; will be dropped
 672         default:  assert(false);
 673         }
 674         return true;
 675     }
 676     private static boolean returnTypesMatch(String sig, Object[] av, Object res) {
 677         MethodHandle mh = (MethodHandle) av[0];
 678         return valueMatches(signatureReturn(sig), mh.type().returnType(), res);
 679     }
 680     private static boolean checkInt(Class<?> type, Object x) {
 681         assert(x instanceof Integer);
 682         if (type == int.class)  return true;
 683         Wrapper w = Wrapper.forBasicType(type);
 684         assert(w.isSubwordOrInt());
 685         Object x1 = Wrapper.INT.wrap(w.wrap(x));
 686         return x.equals(x1);
 687     }
 688     private static boolean checkRef(Class<?> type, Object x) {
 689         assert(!type.isPrimitive());
 690         if (x == null)  return true;
 691         if (type.isInterface())  return true;


 830                 if (i+1 < arity)  buf.append(",");
 831                 continue;
 832             }
 833             buf.append("=").append(n.exprString());
 834             buf.append(";");
 835         }
 836         buf.append(result < 0 ? "void" : names[result]).append("}");
 837         if (TRACE_INTERPRETER) {
 838             // Extra verbosity:
 839             buf.append(":").append(basicTypeSignature());
 840             buf.append("/").append(vmentry);
 841         }
 842         return buf.toString();
 843     }
 844 
 845     /**
 846      * Apply immediate binding for a Name in this form indicated by its position relative to the form.
 847      * The first parameter to a LambdaForm, a0:L, always represents the form's method handle, so 0 is not
 848      * accepted as valid.
 849      */
 850     LambdaForm bindImmediate(int pos, BasicType basicType, Object value) {
 851         // must be an argument, and the types must match
 852         assert pos > 0 && pos < arity && names[pos].type == basicType && Name.typesMatch(basicType, value);
 853 
 854         int arity2 = arity - 1;
 855         Name[] names2 = new Name[names.length - 1];
 856         for (int r = 0, w = 0; r < names.length; ++r, ++w) { // (r)ead from names, (w)rite to names2
 857             Name n = names[r];
 858             if (n.isParam()) {
 859                 if (n.index == pos) {
 860                     // do not copy over the argument that is to be replaced with a literal,
 861                     // but adjust the write index
 862                     --w;
 863                 } else {
 864                     names2[w] = new Name(w, n.type);
 865                 }
 866             } else {
 867                 Object[] arguments2 = new Object[n.arguments.length];
 868                 for (int i = 0; i < n.arguments.length; ++i) {
 869                     Object arg = n.arguments[i];
 870                     if (arg instanceof Name) {


 876                             arguments2[i] = names2[ni];
 877                         } else {
 878                             // replacement position passed
 879                             arguments2[i] = names2[ni - 1];
 880                         }
 881                     } else {
 882                         arguments2[i] = arg;
 883                     }
 884                 }
 885                 names2[w] = new Name(n.function, arguments2);
 886                 names2[w].initIndex(w);
 887             }
 888         }
 889 
 890         int result2 = result == -1 ? -1 : result - 1;
 891         return new LambdaForm(debugName, arity2, names2, result2);
 892     }
 893 
 894     LambdaForm bind(int namePos, BoundMethodHandle.SpeciesData oldData) {
 895         Name name = names[namePos];
 896         BoundMethodHandle.SpeciesData newData = oldData.extendWith(name.type);
 897         return bind(name, new Name(newData.getterFunction(oldData.fieldCount()), names[0]), oldData, newData);
 898     }
 899     LambdaForm bind(Name name, Name binding,
 900                     BoundMethodHandle.SpeciesData oldData,
 901                     BoundMethodHandle.SpeciesData newData) {
 902         int pos = name.index;
 903         assert(name.isParam());
 904         assert(!binding.isParam());
 905         assert(name.type == binding.type);
 906         assert(0 <= pos && pos < arity && names[pos] == name);
 907         assert(binding.function.memberDeclaringClassOrNull() == newData.clazz);
 908         assert(oldData.getters.length == newData.getters.length-1);
 909         if (bindCache != null) {
 910             LambdaForm form = bindCache[pos];
 911             if (form != null) {
 912                 assert(form.contains(binding)) : "form << " + form + " >> does not contain binding << " + binding + " >>";
 913                 return form;
 914             }
 915         } else {
 916             bindCache = new LambdaForm[arity];
 917         }


 968         if (result2 == pos)
 969             result2 = insPos;
 970         else if (result2 > pos && result2 <= insPos)
 971             result2 -= 1;
 972 
 973         return bindCache[pos] = new LambdaForm(debugName, arity2, names2, result2);
 974     }
 975 
 976     boolean contains(Name name) {
 977         int pos = name.index();
 978         if (pos >= 0) {
 979             return pos < names.length && name.equals(names[pos]);
 980         }
 981         for (int i = arity; i < names.length; i++) {
 982             if (name.equals(names[i]))
 983                 return true;
 984         }
 985         return false;
 986     }
 987 
 988     LambdaForm addArguments(int pos, BasicType... types) {
 989         assert(pos <= arity);
 990         int length = names.length;
 991         int inTypes = types.length;
 992         Name[] names2 = Arrays.copyOf(names, length + inTypes);
 993         int arity2 = arity + inTypes;
 994         int result2 = result;
 995         if (result2 >= arity)
 996             result2 += inTypes;
 997         // names array has MH in slot 0; skip it.
 998         int argpos = pos + 1;
 999         // Note:  The LF constructor will rename names2[argpos...].
1000         // Make space for new arguments (shift temporaries).
1001         System.arraycopy(names, argpos, names2, argpos + inTypes, length - argpos);
1002         for (int i = 0; i < inTypes; i++) {
1003             names2[argpos + i] = new Name(types[i]);
1004         }
1005         return new LambdaForm(debugName, arity2, names2, result2);
1006     }
1007 
1008     LambdaForm addArguments(int pos, List<Class<?>> types) {
1009         BasicType[] basicTypes = new BasicType[types.size()];
1010         for (int i = 0; i < basicTypes.length; i++)
1011             basicTypes[i] = basicType(types.get(i));
1012         return addArguments(pos, basicTypes);
1013     }
1014 
1015     LambdaForm permuteArguments(int skip, int[] reorder, BasicType[] types) {
1016         // Note:  When inArg = reorder[outArg], outArg is fed by a copy of inArg.
1017         // The types are the types of the new (incoming) arguments.
1018         int length = names.length;
1019         int inTypes = types.length;
1020         int outArgs = reorder.length;
1021         assert(skip+outArgs == arity);
1022         assert(permutedTypesMatch(reorder, types, names, skip));
1023         int pos = 0;
1024         // skip trivial first part of reordering:
1025         while (pos < outArgs && reorder[pos] == pos)  pos += 1;
1026         Name[] names2 = new Name[length - outArgs + inTypes];
1027         System.arraycopy(names, 0, names2, 0, skip+pos);
1028         // copy the body:
1029         int bodyLength = length - arity;
1030         System.arraycopy(names, skip+outArgs, names2, skip+inTypes, bodyLength);
1031         int arity2 = names2.length - bodyLength;
1032         int result2 = result;
1033         if (result2 >= 0) {
1034             if (result2 < skip+outArgs) {
1035                 // return the corresponding inArg


1054         }
1055         // some names are unused, but must be filled in
1056         for (int i = skip+pos; i < arity2; i++) {
1057             if (names2[i] == null)
1058                 names2[i] = argument(i, types[i - skip]);
1059         }
1060         for (int j = arity; j < names.length; j++) {
1061             int i = j - arity + arity2;
1062             // replace names2[i] by names[j]
1063             Name n = names[j];
1064             Name n2 = names2[i];
1065             if (n != n2) {
1066                 for (int k = i+1; k < names2.length; k++) {
1067                     names2[k] = names2[k].replaceName(n, n2);
1068                 }
1069             }
1070         }
1071         return new LambdaForm(debugName, arity2, names2, result2);
1072     }
1073 
1074     static boolean permutedTypesMatch(int[] reorder, BasicType[] types, Name[] names, int skip) {
1075         int inTypes = types.length;
1076         int outArgs = reorder.length;
1077         for (int i = 0; i < outArgs; i++) {
1078             assert(names[skip+i].isParam());
1079             assert(names[skip+i].type == types[reorder[i]]);
1080         }
1081         return true;
1082     }
1083 
1084     static class NamedFunction {
1085         final MemberName member;
1086         @Stable MethodHandle resolvedHandle;
1087         @Stable MethodHandle invoker;
1088 
1089         NamedFunction(MethodHandle resolvedHandle) {
1090             this(resolvedHandle.internalMemberName(), resolvedHandle);
1091         }
1092         NamedFunction(MemberName member, MethodHandle resolvedHandle) {
1093             this.member = member;
1094             //resolvedHandle = eraseSubwordTypes(resolvedHandle);


1138             return this.member != null && this.member.equals(that.member);
1139         }
1140 
1141         @Override
1142         public int hashCode() {
1143             if (member != null)
1144                 return member.hashCode();
1145             return super.hashCode();
1146         }
1147 
1148         // Put the predefined NamedFunction invokers into the table.
1149         static void initializeInvokers() {
1150             for (MemberName m : MemberName.getFactory().getMethods(NamedFunction.class, false, null, null, null)) {
1151                 if (!m.isStatic() || !m.isPackage())  continue;
1152                 MethodType type = m.getMethodType();
1153                 if (type.equals(INVOKER_METHOD_TYPE) &&
1154                     m.getName().startsWith("invoke_")) {
1155                     String sig = m.getName().substring("invoke_".length());
1156                     int arity = LambdaForm.signatureArity(sig);
1157                     MethodType srcType = MethodType.genericMethodType(arity);
1158                     if (LambdaForm.signatureReturn(sig) == V_TYPE)
1159                         srcType = srcType.changeReturnType(void.class);
1160                     MethodTypeForm typeForm = srcType.form();
1161                     typeForm.namedFunctionInvoker = DirectMethodHandle.make(m);
1162                 }
1163             }
1164         }
1165 
1166         // The following are predefined NamedFunction invokers.  The system must build
1167         // a separate invoker for each distinct signature.
1168         /** void return type invokers. */
1169         @Hidden
1170         static Object invoke__V(MethodHandle mh, Object[] a) throws Throwable {
1171             assert(a.length == 0);
1172             mh.invokeBasic();
1173             return null;
1174         }
1175         @Hidden
1176         static Object invoke_L_V(MethodHandle mh, Object[] a) throws Throwable {
1177             assert(a.length == 1);
1178             mh.invokeBasic(a[0]);


1228             assert(a.length == 4);
1229             return mh.invokeBasic(a[0], a[1], a[2], a[3]);
1230         }
1231         @Hidden
1232         static Object invoke_LLLLL_L(MethodHandle mh, Object[] a) throws Throwable {
1233             assert(a.length == 5);
1234             return mh.invokeBasic(a[0], a[1], a[2], a[3], a[4]);
1235         }
1236 
1237         static final MethodType INVOKER_METHOD_TYPE =
1238             MethodType.methodType(Object.class, MethodHandle.class, Object[].class);
1239 
1240         private static MethodHandle computeInvoker(MethodTypeForm typeForm) {
1241             MethodHandle mh = typeForm.namedFunctionInvoker;
1242             if (mh != null)  return mh;
1243             MemberName invoker = InvokerBytecodeGenerator.generateNamedFunctionInvoker(typeForm);  // this could take a while
1244             mh = DirectMethodHandle.make(invoker);
1245             MethodHandle mh2 = typeForm.namedFunctionInvoker;
1246             if (mh2 != null)  return mh2;  // benign race
1247             if (!mh.type().equals(INVOKER_METHOD_TYPE))
1248                 throw newInternalError(mh.debugString());
1249             return typeForm.namedFunctionInvoker = mh;
1250         }
1251 
1252         @Hidden
1253         Object invokeWithArguments(Object... arguments) throws Throwable {
1254             // If we have a cached invoker, call it right away.
1255             // NOTE: The invoker always returns a reference value.
1256             if (TRACE_INTERPRETER)  return invokeWithArgumentsTracing(arguments);
1257             assert(checkArgumentTypes(arguments, methodType()));
1258             return invoker().invokeBasic(resolvedHandle(), arguments);
1259         }
1260 
1261         @Hidden
1262         Object invokeWithArgumentsTracing(Object[] arguments) throws Throwable {
1263             Object rval;
1264             try {
1265                 traceInterpreter("[ call", this, arguments);
1266                 if (invoker == null) {
1267                     traceInterpreter("| getInvoker", this);
1268                     invoker();


1318         }
1319 
1320         MemberName member() {
1321             assert(assertMemberIsConsistent());
1322             return member;
1323         }
1324 
1325         // Called only from assert.
1326         private boolean assertMemberIsConsistent() {
1327             if (resolvedHandle instanceof DirectMethodHandle) {
1328                 MemberName m = resolvedHandle.internalMemberName();
1329                 assert(m.equals(member));
1330             }
1331             return true;
1332         }
1333 
1334         Class<?> memberDeclaringClassOrNull() {
1335             return (member == null) ? null : member.getDeclaringClass();
1336         }
1337 
1338         BasicType returnType() {
1339             return basicType(methodType().returnType());
1340         }
1341 
1342         BasicType parameterType(int n) {
1343             return basicType(methodType().parameterType(n));
1344         }
1345 
1346         int arity() {
1347             //int siglen = member.getMethodType().parameterCount();
1348             //if (!member.isStatic())  siglen += 1;
1349             //return siglen;
1350             return methodType().parameterCount();
1351         }
1352 
1353         public String toString() {
1354             if (member == null)  return String.valueOf(resolvedHandle);
1355             return member.getDeclaringClass().getSimpleName()+"."+member.getName();
1356         }

1357 
1358         public boolean isIdentity() {
1359             return this.equals(identity(returnType()));
1360         }
1361 
1362         public boolean isConstantZero() {
1363             return this.equals(constantZero(returnType()));



1364         }




1365     }
1366 
1367     void resolve() {
1368         for (Name n : names) n.resolve();
1369     }
1370 
1371     public static String basicTypeSignature(MethodType type) {
1372         char[] sig = new char[type.parameterCount() + 2];
1373         int sigp = 0;
1374         for (Class<?> pt : type.parameterList()) {
1375             sig[sigp++] = basicTypeChar(pt);
1376         }
1377         sig[sigp++] = '_';
1378         sig[sigp++] = basicTypeChar(type.returnType());
1379         assert(sigp == sig.length);
1380         return String.valueOf(sig);
1381     }
1382     public static String shortenSignature(String signature) {
1383         // Hack to make signatures more readable when they show up in method names.
1384         final int NO_CHAR = -1, MIN_RUN = 3;
1385         int c0, c1 = NO_CHAR, c1reps = 0;
1386         StringBuilder buf = null;
1387         int len = signature.length();
1388         if (len < MIN_RUN)  return signature;
1389         for (int i = 0; i <= len; i++) {
1390             // shift in the next char:
1391             c0 = c1; c1 = (i == len ? NO_CHAR : signature.charAt(i));
1392             if (c1 == c0) { ++c1reps; continue; }
1393             // shift in the next count:
1394             int c0reps = c1reps; c1reps = 1;
1395             // end of a  character run
1396             if (c0reps < MIN_RUN) {
1397                 if (buf != null) {
1398                     while (--c0reps >= 0)
1399                         buf.append((char)c0);
1400                 }
1401                 continue;
1402             }
1403             // found three or more in a row
1404             if (buf == null)
1405                 buf = new StringBuilder().append(signature, 0, i - c0reps);
1406             buf.append((char)c0).append(c0reps);
1407         }
1408         return (buf == null) ? signature : buf.toString();
1409     }
1410 
1411     static final class Name {
1412         final BasicType type;
1413         private short index;
1414         final NamedFunction function;
1415         @Stable final Object[] arguments;
1416 
1417         private Name(int index, BasicType type, NamedFunction function, Object[] arguments) {
1418             this.index = (short)index;
1419             this.type = type;
1420             this.function = function;
1421             this.arguments = arguments;
1422             assert(this.index == index);
1423         }
1424         Name(MethodHandle function, Object... arguments) {
1425             this(new NamedFunction(function), arguments);
1426         }
1427         Name(MethodType functionType, Object... arguments) {
1428             this(new NamedFunction(functionType), arguments);
1429             assert(arguments[0] instanceof Name && ((Name)arguments[0]).type == L_TYPE);
1430         }
1431         Name(MemberName function, Object... arguments) {
1432             this(new NamedFunction(function), arguments);
1433         }
1434         Name(NamedFunction function, Object... arguments) {
1435             this(-1, function.returnType(), function, arguments = arguments.clone());
1436             assert(arguments.length == function.arity()) : "arity mismatch: arguments.length=" + arguments.length + " == function.arity()=" + function.arity() + " in " + debugString();
1437             for (int i = 0; i < arguments.length; i++)
1438                 assert(typesMatch(function.parameterType(i), arguments[i])) : "types don't match: function.parameterType(" + i + ")=" + function.parameterType(i) + ", arguments[" + i + "]=" + arguments[i] + " in " + debugString();
1439         }
1440         /** Create a raw parameter of the given type, with an expected index. */
1441         Name(int index, BasicType type) {
1442             this(index, type, null, null);
1443         }
1444         /** Create a raw parameter of the given type. */
1445         Name(BasicType type) { this(-1, type); }

1446 
1447         BasicType type() { return type; }
1448         int index() { return index; }
1449         boolean initIndex(int i) {
1450             if (index != i) {
1451                 if (index != -1)  return false;
1452                 index = (short)i;
1453             }
1454             return true;
1455         }
1456         char typeChar() {
1457             return type.btChar;
1458         }
1459 
1460         void resolve() {
1461             if (function != null)
1462                 function.resolve();
1463         }
1464 
1465         Name newIndex(int i) {
1466             if (initIndex(i))  return this;
1467             return cloneWithIndex(i);
1468         }
1469         Name cloneWithIndex(int i) {
1470             Object[] newArguments = (arguments == null) ? null : arguments.clone();
1471             return new Name(i, type, function, newArguments);
1472         }
1473         Name replaceName(Name oldName, Name newName) {  // FIXME: use replaceNames uniformly
1474             if (oldName == newName)  return this;
1475             @SuppressWarnings("LocalVariableHidesMemberVariable")
1476             Object[] arguments = this.arguments;
1477             if (arguments == null)  return this;
1478             boolean replaced = false;


1516                 }
1517             }
1518             if (!replaced)  return this;
1519             return new Name(function, arguments);
1520         }
1521         void internArguments() {
1522             @SuppressWarnings("LocalVariableHidesMemberVariable")
1523             Object[] arguments = this.arguments;
1524             for (int j = 0; j < arguments.length; j++) {
1525                 if (arguments[j] instanceof Name) {
1526                     Name n = (Name) arguments[j];
1527                     if (n.isParam() && n.index < INTERNED_ARGUMENT_LIMIT)
1528                         arguments[j] = internArgument(n);
1529                 }
1530             }
1531         }
1532         boolean isParam() {
1533             return function == null;
1534         }
1535         boolean isConstantZero() {
1536             return !isParam() && arguments.length == 0 && function.isConstantZero();
1537         }
1538 
1539         public String toString() {
1540             return (isParam()?"a":"t")+(index >= 0 ? index : System.identityHashCode(this))+":"+typeChar();
1541         }
1542         public String debugString() {
1543             String s = toString();
1544             return (function == null) ? s : s + "=" + exprString();
1545         }
1546         public String exprString() {
1547             if (function == null)  return toString();
1548             StringBuilder buf = new StringBuilder(function.toString());
1549             buf.append("(");
1550             String cma = "";
1551             for (Object a : arguments) {
1552                 buf.append(cma); cma = ",";
1553                 if (a instanceof Name || a instanceof Integer)
1554                     buf.append(a);
1555                 else
1556                     buf.append("(").append(a).append(")");
1557             }
1558             buf.append(")");
1559             return buf.toString();
1560         }
1561 
1562         static boolean typesMatch(BasicType parameterType, Object object) {
1563             if (object instanceof Name) {
1564                 return ((Name)object).type == parameterType;
1565             }
1566             switch (parameterType) {
1567                 case I_TYPE:  return object instanceof Integer;
1568                 case J_TYPE:  return object instanceof Long;
1569                 case F_TYPE:  return object instanceof Float;
1570                 case D_TYPE:  return object instanceof Double;
1571             }
1572             assert(parameterType == L_TYPE);
1573             return true;
1574         }
1575 
1576         /**
1577          * Does this Name precede the given binding node in some canonical order?
1578          * This predicate is used to order data bindings (via insertion sort)
1579          * with some stability.
1580          */
1581         boolean isSiblingBindingBefore(Name binding) {
1582             assert(!binding.isParam());
1583             if (isParam())  return true;
1584             if (function.equals(binding.function) &&
1585                 arguments.length == binding.arguments.length) {
1586                 boolean sawInt = false;
1587                 for (int i = 0; i < arguments.length; i++) {
1588                     Object a1 = arguments[i];
1589                     Object a2 = binding.arguments[i];
1590                     if (!a1.equals(a2)) {
1591                         if (a1 instanceof Integer && a2 instanceof Integer) {
1592                             if (sawInt)  continue;


1629         }
1630 
1631         public boolean equals(Name that) {
1632             if (this == that)  return true;
1633             if (isParam())
1634                 // each parameter is a unique atom
1635                 return false;  // this != that
1636             return
1637                 //this.index == that.index &&
1638                 this.type == that.type &&
1639                 this.function.equals(that.function) &&
1640                 Arrays.equals(this.arguments, that.arguments);
1641         }
1642         @Override
1643         public boolean equals(Object x) {
1644             return x instanceof Name && equals((Name)x);
1645         }
1646         @Override
1647         public int hashCode() {
1648             if (isParam())
1649                 return index | (type.ordinal() << 8);
1650             return function.hashCode() ^ Arrays.hashCode(arguments);
1651         }
1652     }
1653 
1654     /** Return the index of the last name which contains n as an argument.
1655      *  Return -1 if the name is not used.  Return names.length if it is the return value.
1656      */
1657     int lastUseIndex(Name n) {
1658         int ni = n.index, nmax = names.length;
1659         assert(names[ni] == n);
1660         if (result == ni)  return nmax;  // live all the way beyond the end
1661         for (int i = nmax; --i > ni; ) {
1662             if (names[i].lastUseIndex(n) >= 0)
1663                 return i;
1664         }
1665         return -1;
1666     }
1667 
1668     /** Return the number of times n is used as an argument or return value. */
1669     int useCount(Name n) {
1670         int ni = n.index, nmax = names.length;
1671         int end = lastUseIndex(n);
1672         if (end < 0)  return 0;
1673         int count = 0;
1674         if (end == nmax) { count++; end--; }
1675         int beg = n.index() + 1;
1676         if (beg < arity)  beg = arity;
1677         for (int i = beg; i <= end; i++) {
1678             count += names[i].useCount(n);
1679         }
1680         return count;
1681     }
1682 
1683     static Name argument(int which, char type) {
1684         return argument(which, basicType(type));
1685     }
1686     static Name argument(int which, BasicType type) {
1687         if (which >= INTERNED_ARGUMENT_LIMIT)
1688             return new Name(which, type);
1689         return INTERNED_ARGUMENTS[type.ordinal()][which];
1690     }
1691     static Name internArgument(Name n) {
1692         assert(n.isParam()) : "not param: " + n;
1693         assert(n.index < INTERNED_ARGUMENT_LIMIT);
1694         return argument(n.index, n.type);
1695     }
1696     static Name[] arguments(int extra, String types) {
1697         int length = types.length();
1698         Name[] names = new Name[length + extra];
1699         for (int i = 0; i < length; i++)
1700             names[i] = argument(i, types.charAt(i));
1701         return names;
1702     }
1703     static Name[] arguments(int extra, char... types) {
1704         int length = types.length;
1705         Name[] names = new Name[length + extra];
1706         for (int i = 0; i < length; i++)
1707             names[i] = argument(i, types[i]);
1708         return names;
1709     }


1711         int length = types.size();
1712         Name[] names = new Name[length + extra];
1713         for (int i = 0; i < length; i++)
1714             names[i] = argument(i, basicType(types.get(i)));
1715         return names;
1716     }
1717     static Name[] arguments(int extra, Class<?>... types) {
1718         int length = types.length;
1719         Name[] names = new Name[length + extra];
1720         for (int i = 0; i < length; i++)
1721             names[i] = argument(i, basicType(types[i]));
1722         return names;
1723     }
1724     static Name[] arguments(int extra, MethodType types) {
1725         int length = types.parameterCount();
1726         Name[] names = new Name[length + extra];
1727         for (int i = 0; i < length; i++)
1728             names[i] = argument(i, basicType(types.parameterType(i)));
1729         return names;
1730     }

1731     static final int INTERNED_ARGUMENT_LIMIT = 10;
1732     private static final Name[][] INTERNED_ARGUMENTS
1733             = new Name[ARG_TYPE_LIMIT][INTERNED_ARGUMENT_LIMIT];
1734     static {
1735         for (BasicType type : BasicType.ARG_TYPES) {
1736             int ord = type.ordinal();
1737             for (int i = 0; i < INTERNED_ARGUMENTS[ord].length; i++) {
1738                 INTERNED_ARGUMENTS[ord][i] = new Name(i, type);
1739             }
1740         }
1741     }
1742 
1743     private static final MemberName.Factory IMPL_NAMES = MemberName.getFactory();
1744 
1745     static LambdaForm identityForm(BasicType type) {
1746         return LF_identityForm[type.ordinal()];
1747     }
1748     static LambdaForm zeroForm(BasicType type) {
1749         return LF_zeroForm[type.ordinal()];
1750     }
1751     static NamedFunction identity(BasicType type) {
1752         return NF_identity[type.ordinal()];
1753     }
1754     static NamedFunction constantZero(BasicType type) {
1755         return NF_zero[type.ordinal()];
1756     }
1757     private static final LambdaForm[] LF_identityForm = new LambdaForm[TYPE_LIMIT];
1758     private static final LambdaForm[] LF_zeroForm = new LambdaForm[TYPE_LIMIT];
1759     private static final NamedFunction[] NF_identity = new NamedFunction[TYPE_LIMIT];
1760     private static final NamedFunction[] NF_zero = new NamedFunction[TYPE_LIMIT];
1761     private static void createIdentityForms() {
1762         for (BasicType type : BasicType.ALL_TYPES) {
1763             int ord = type.ordinal();
1764             char btChar = type.basicTypeChar();
1765             boolean isVoid = (type == V_TYPE);
1766             Class<?> btClass = type.btClass;
1767             MethodType zeType = MethodType.methodType(btClass);
1768             MethodType idType = isVoid ? zeType : zeType.appendParameterTypes(btClass);
1769 
1770             // Look up some symbolic names.  It might not be necessary to have these,
1771             // but if we need to emit direct references to bytecodes, it helps.
1772             // Zero is built from a call to an identity function with a constant zero input.
1773             MemberName idMem = new MemberName(LambdaForm.class, "identity_"+btChar, idType, REF_invokeStatic);
1774             MemberName zeMem = new MemberName(LambdaForm.class, "zero_"+btChar, zeType, REF_invokeStatic);
1775             try {
1776                 zeMem = IMPL_NAMES.resolveOrFail(REF_invokeStatic, zeMem, null, NoSuchMethodException.class);
1777                 idMem = IMPL_NAMES.resolveOrFail(REF_invokeStatic, idMem, null, NoSuchMethodException.class);
1778             } catch (IllegalAccessException|NoSuchMethodException ex) {
1779                 throw newInternalError(ex);
1780             }
1781 
1782             NamedFunction idFun = new NamedFunction(idMem);
1783             LambdaForm idForm;
1784             if (isVoid) {
1785                 Name[] idNames = new Name[] { argument(0, L_TYPE) };
1786                 idForm = new LambdaForm(idMem.getName(), 1, idNames, VOID_RESULT);
1787             } else {
1788                 Name[] idNames = new Name[] { argument(0, L_TYPE), argument(1, type) };
1789                 idForm = new LambdaForm(idMem.getName(), 2, idNames, 1);
1790             }
1791             LF_identityForm[ord] = idForm;
1792             NF_identity[ord] = idFun;
1793             //idFun.resolvedHandle = SimpleMethodHandle.make(idMem.getInvocationType(), idForm);
1794 
1795             NamedFunction zeFun = new NamedFunction(zeMem);
1796             LambdaForm zeForm;
1797             if (isVoid) {
1798                 zeForm = idForm;
1799             } else {
1800                 Object zeValue = Wrapper.forBasicType(btChar).zero();
1801                 Name[] zeNames = new Name[] { argument(0, L_TYPE), new Name(idFun, zeValue) };
1802                 zeForm = new LambdaForm(zeMem.getName(), 1, zeNames, 1);
1803             }
1804             LF_zeroForm[ord] = zeForm;
1805             NF_zero[ord] = zeFun;
1806             //zeFun.resolvedHandle = SimpleMethodHandle.make(zeMem.getInvocationType(), zeForm);
1807 
1808             assert(idFun.isIdentity());
1809             assert(zeFun.isConstantZero());
1810             assert(new Name(zeFun).isConstantZero());
1811         }
1812 
1813         // Do this in a separate pass, so that SimpleMethodHandle.make can see the tables.
1814         for (BasicType type : BasicType.ALL_TYPES) {
1815             int ord = type.ordinal();
1816             NamedFunction idFun = NF_identity[ord];
1817             LambdaForm idForm = LF_identityForm[ord];
1818             MemberName idMem = idFun.member;
1819             idFun.resolvedHandle = SimpleMethodHandle.make(idMem.getInvocationType(), idForm);
1820 
1821             NamedFunction zeFun = NF_zero[ord];
1822             LambdaForm zeForm = LF_zeroForm[ord];
1823             MemberName zeMem = zeFun.member;
1824             zeFun.resolvedHandle = SimpleMethodHandle.make(zeMem.getInvocationType(), zeForm);
1825 
1826             assert(idFun.isIdentity());
1827             assert(zeFun.isConstantZero());
1828             assert(new Name(zeFun).isConstantZero());
1829         }
1830     }
1831 
1832     // Avoid appealing to ValueConversions at bootstrap time:
1833     private static int identity_I(int x) { return x; }
1834     private static long identity_J(long x) { return x; }
1835     private static float identity_F(float x) { return x; }
1836     private static double identity_D(double x) { return x; }
1837     private static Object identity_L(Object x) { return x; }
1838     private static void identity_V() { return; }  // same as zeroV, but that's OK
1839     private static int zero_I() { return 0; }
1840     private static long zero_J() { return 0; }
1841     private static float zero_F() { return 0; }
1842     private static double zero_D() { return 0; }
1843     private static Object zero_L() { return null; }
1844     private static void zero_V() { return; }
1845 
1846     /**
1847      * Internal marker for byte-compiled LambdaForms.
1848      */
1849     /*non-public*/
1850     @Target(ElementType.METHOD)
1851     @Retention(RetentionPolicy.RUNTIME)
1852     @interface Compiled {
1853     }
1854 
1855     /**
1856      * Internal marker for LambdaForm interpreter frames.
1857      */
1858     /*non-public*/
1859     @Target(ElementType.METHOD)
1860     @Retention(RetentionPolicy.RUNTIME)
1861     @interface Hidden {
1862     }
1863 
1864 


1875         Object[] abc = { "a", "bc" };
1876         List<?> lst = (List<?>) MethodHandle.linkToStatic(abc, asList_MN);
1877         System.out.println("lst="+lst);
1878         MemberName toString_MN = new MemberName(Object.class.getMethod("toString"));
1879         String s1 = (String) MethodHandle.linkToVirtual(lst, toString_MN);
1880         toString_MN = new MemberName(Object.class.getMethod("toString"), true);
1881         String s2 = (String) MethodHandle.linkToSpecial(lst, toString_MN);
1882         System.out.println("[s1,s2,lst]="+Arrays.asList(s1, s2, lst.toString()));
1883         MemberName toArray_MN = new MemberName(List.class.getMethod("toArray"));
1884         Object[] arr = (Object[]) MethodHandle.linkToInterface(lst, toArray_MN);
1885         System.out.println("toArray="+Arrays.toString(arr));
1886     }
1887     static { try { testMethodHandleLinkers(); } catch (Throwable ex) { throw new RuntimeException(ex); } }
1888     // Requires these definitions in MethodHandle:
1889     static final native Object linkToStatic(Object x1, MemberName mn) throws Throwable;
1890     static final native Object linkToVirtual(Object x1, MemberName mn) throws Throwable;
1891     static final native Object linkToSpecial(Object x1, MemberName mn) throws Throwable;
1892     static final native Object linkToInterface(Object x1, MemberName mn) throws Throwable;
1893  */
1894 
1895     private static final HashMap<String,Integer> DEBUG_NAME_COUNTERS;
1896     static {
1897         if (debugEnabled())
1898             DEBUG_NAME_COUNTERS = new HashMap<>();
1899         else
1900             DEBUG_NAME_COUNTERS = null;
1901     }
1902 
1903     // Put this last, so that previous static inits can run before.
1904     static {
1905         createIdentityForms();
1906         if (USE_PREDEFINED_INTERPRET_METHODS)
1907             PREPARED_FORMS.putAll(computeInitialPreparedForms());
1908         NamedFunction.initializeInvokers();
1909     }
1910 
1911     // The following hack is necessary in order to suppress TRACE_INTERPRETER
1912     // during execution of the static initializes of this class.
1913     // Turning on TRACE_INTERPRETER too early will cause
1914     // stack overflows and other misbehavior during attempts to trace events
1915     // that occur during LambdaForm.<clinit>.
1916     // Therefore, do not move this line higher in this file, and do not remove.
1917     private static final boolean TRACE_INTERPRETER = MethodHandleStatics.TRACE_INTERPRETER;
1918 }
src/share/classes/java/lang/invoke/LambdaForm.java
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