1 /*
   2  * Copyright (c) 2008, 2011, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_VM_PRIMS_METHODHANDLES_HPP
  26 #define SHARE_VM_PRIMS_METHODHANDLES_HPP
  27 
  28 #include "classfile/javaClasses.hpp"
  29 #include "classfile/vmSymbols.hpp"
  30 #include "runtime/frame.inline.hpp"
  31 #include "runtime/globals.hpp"
  32 #include "runtime/interfaceSupport.hpp"
  33 
  34 class MacroAssembler;
  35 class Label;
  36 class MethodHandleEntry;
  37 
  38 class MethodHandles: AllStatic {
  39   // JVM support for MethodHandle, MethodType, and related types
  40   // in java.lang.invoke and sun.invoke.
  41   // See also  javaClasses for layouts java_lang_invoke_Method{Handle,Type,Type::Form}.
  42  public:
  43   enum EntryKind {
  44     _raise_exception,           // stub for error generation from other stubs
  45     _invokestatic_mh,           // how a MH emulates invokestatic
  46     _invokespecial_mh,          // ditto for the other invokes...
  47     _invokevirtual_mh,
  48     _invokeinterface_mh,
  49     _bound_ref_mh,              // reference argument is bound
  50     _bound_int_mh,              // int argument is bound (via an Integer or Float)
  51     _bound_long_mh,             // long argument is bound (via a Long or Double)
  52     _bound_ref_direct_mh,       // same as above, with direct linkage to methodOop
  53     _bound_int_direct_mh,
  54     _bound_long_direct_mh,
  55 
  56     _adapter_mh_first,     // adapter sequence goes here...
  57     _adapter_retype_only   = _adapter_mh_first + java_lang_invoke_AdapterMethodHandle::OP_RETYPE_ONLY,
  58     _adapter_retype_raw    = _adapter_mh_first + java_lang_invoke_AdapterMethodHandle::OP_RETYPE_RAW,
  59     _adapter_check_cast    = _adapter_mh_first + java_lang_invoke_AdapterMethodHandle::OP_CHECK_CAST,
  60     _adapter_prim_to_prim  = _adapter_mh_first + java_lang_invoke_AdapterMethodHandle::OP_PRIM_TO_PRIM,
  61     _adapter_ref_to_prim   = _adapter_mh_first + java_lang_invoke_AdapterMethodHandle::OP_REF_TO_PRIM,
  62     _adapter_prim_to_ref   = _adapter_mh_first + java_lang_invoke_AdapterMethodHandle::OP_PRIM_TO_REF,
  63     _adapter_swap_args     = _adapter_mh_first + java_lang_invoke_AdapterMethodHandle::OP_SWAP_ARGS,
  64     _adapter_rot_args      = _adapter_mh_first + java_lang_invoke_AdapterMethodHandle::OP_ROT_ARGS,
  65     _adapter_dup_args      = _adapter_mh_first + java_lang_invoke_AdapterMethodHandle::OP_DUP_ARGS,
  66     _adapter_drop_args     = _adapter_mh_first + java_lang_invoke_AdapterMethodHandle::OP_DROP_ARGS,
  67     _adapter_collect_args  = _adapter_mh_first + java_lang_invoke_AdapterMethodHandle::OP_COLLECT_ARGS,
  68     _adapter_spread_args   = _adapter_mh_first + java_lang_invoke_AdapterMethodHandle::OP_SPREAD_ARGS,
  69     _adapter_fold_args     = _adapter_mh_first + java_lang_invoke_AdapterMethodHandle::OP_FOLD_ARGS,
  70     _adapter_unused_13     = _adapter_mh_first + 13,  //hole in the CONV_OP enumeration
  71     _adapter_mh_last       = _adapter_mh_first + java_lang_invoke_AdapterMethodHandle::CONV_OP_LIMIT - 1,
  72 
  73     // Optimized adapter types
  74 
  75     // argument list reordering
  76     _adapter_opt_swap_1,
  77     _adapter_opt_swap_2,
  78     _adapter_opt_rot_1_up,
  79     _adapter_opt_rot_1_down,
  80     _adapter_opt_rot_2_up,
  81     _adapter_opt_rot_2_down,
  82     // primitive single to single:
  83     _adapter_opt_i2i,           // i2c, i2z, i2b, i2s
  84     // primitive double to single:
  85     _adapter_opt_l2i,
  86     _adapter_opt_d2f,
  87     // primitive single to double:
  88     _adapter_opt_i2l,
  89     _adapter_opt_f2d,
  90     // conversion between floating point and integer type is handled by Java
  91 
  92     // reference to primitive:
  93     _adapter_opt_unboxi,
  94     _adapter_opt_unboxl,
  95 
  96     // %% Maybe tame the following with a VM_SYMBOLS_DO type macro?
  97 
  98     // how a blocking adapter returns (platform-dependent)
  99     _adapter_opt_return_ref,
 100     _adapter_opt_return_int,
 101     _adapter_opt_return_long,
 102     _adapter_opt_return_float,
 103     _adapter_opt_return_double,
 104     _adapter_opt_return_void,
 105     _adapter_opt_return_S0_ref,  // return ref to S=0 (last slot)
 106     _adapter_opt_return_S1_ref,  // return ref to S=1 (2nd-to-last slot)
 107     _adapter_opt_return_S2_ref,
 108     _adapter_opt_return_S3_ref,
 109     _adapter_opt_return_S4_ref,
 110     _adapter_opt_return_S5_ref,
 111     _adapter_opt_return_any,     // dynamically select r/i/l/f/d
 112     _adapter_opt_return_FIRST = _adapter_opt_return_ref,
 113     _adapter_opt_return_LAST  = _adapter_opt_return_any,
 114 
 115     // spreading (array length cases 0, 1, ...)
 116     _adapter_opt_spread_0,       // spread empty array to N=0 arguments
 117     _adapter_opt_spread_1_ref,   // spread Object[] to N=1 argument
 118     _adapter_opt_spread_2_ref,   // spread Object[] to N=2 arguments
 119     _adapter_opt_spread_3_ref,   // spread Object[] to N=3 arguments
 120     _adapter_opt_spread_4_ref,   // spread Object[] to N=4 arguments
 121     _adapter_opt_spread_5_ref,   // spread Object[] to N=5 arguments
 122     _adapter_opt_spread_ref,     // spread Object[] to N arguments
 123     _adapter_opt_spread_byte,    // spread byte[] or boolean[] to N arguments
 124     _adapter_opt_spread_char,    // spread char[], etc., to N arguments
 125     _adapter_opt_spread_short,   // spread short[], etc., to N arguments
 126     _adapter_opt_spread_int,     // spread int[], short[], etc., to N arguments
 127     _adapter_opt_spread_long,    // spread long[] to N arguments
 128     _adapter_opt_spread_float,   // spread float[] to N arguments
 129     _adapter_opt_spread_double,  // spread double[] to N arguments
 130     _adapter_opt_spread_FIRST = _adapter_opt_spread_0,
 131     _adapter_opt_spread_LAST  = _adapter_opt_spread_double,
 132 
 133     // blocking filter/collect conversions
 134     // These collect N arguments and replace them (at slot S) by a return value
 135     // which is passed to the final target, along with the unaffected arguments.
 136     // collect_{N}_{T} collects N arguments at any position into a T value
 137     // collect_{N}_S{S}_{T} collects N arguments at slot S into a T value
 138     // collect_{T} collects any number of arguments at any position
 139     // filter_S{S}_{T} is the same as collect_1_S{S}_{T} (a unary collection)
 140     // (collect_2 is also usable as a filter, with long or double arguments)
 141     _adapter_opt_collect_ref,    // combine N arguments, replace with a reference
 142     _adapter_opt_collect_int,    // combine N arguments, replace with an int, short, etc.
 143     _adapter_opt_collect_long,   // combine N arguments, replace with a long
 144     _adapter_opt_collect_float,  // combine N arguments, replace with a float
 145     _adapter_opt_collect_double, // combine N arguments, replace with a double
 146     _adapter_opt_collect_void,   // combine N arguments, replace with nothing
 147     // if there is a small fixed number to push, do so without a loop:
 148     _adapter_opt_collect_0_ref,  // collect N=0 arguments, insert a reference
 149     _adapter_opt_collect_1_ref,  // collect N=1 argument, replace with a reference
 150     _adapter_opt_collect_2_ref,  // combine N=2 arguments, replace with a reference
 151     _adapter_opt_collect_3_ref,  // combine N=3 arguments, replace with a reference
 152     _adapter_opt_collect_4_ref,  // combine N=4 arguments, replace with a reference
 153     _adapter_opt_collect_5_ref,  // combine N=5 arguments, replace with a reference
 154     // filters are an important special case because they never move arguments:
 155     _adapter_opt_filter_S0_ref,  // filter N=1 argument at S=0, replace with a reference
 156     _adapter_opt_filter_S1_ref,  // filter N=1 argument at S=1, replace with a reference
 157     _adapter_opt_filter_S2_ref,  // filter N=1 argument at S=2, replace with a reference
 158     _adapter_opt_filter_S3_ref,  // filter N=1 argument at S=3, replace with a reference
 159     _adapter_opt_filter_S4_ref,  // filter N=1 argument at S=4, replace with a reference
 160     _adapter_opt_filter_S5_ref,  // filter N=1 argument at S=5, replace with a reference
 161     // these move arguments, but they are important for boxing
 162     _adapter_opt_collect_2_S0_ref,  // combine last N=2 arguments, replace with a reference
 163     _adapter_opt_collect_2_S1_ref,  // combine N=2 arguments at S=1, replace with a reference
 164     _adapter_opt_collect_2_S2_ref,  // combine N=2 arguments at S=2, replace with a reference
 165     _adapter_opt_collect_2_S3_ref,  // combine N=2 arguments at S=3, replace with a reference
 166     _adapter_opt_collect_2_S4_ref,  // combine N=2 arguments at S=4, replace with a reference
 167     _adapter_opt_collect_2_S5_ref,  // combine N=2 arguments at S=5, replace with a reference
 168     _adapter_opt_collect_FIRST = _adapter_opt_collect_ref,
 169     _adapter_opt_collect_LAST  = _adapter_opt_collect_2_S5_ref,
 170 
 171     // blocking folding conversions
 172     // these are like collects, but retain all the N arguments for the final target
 173     //_adapter_opt_fold_0_ref,   // same as _adapter_opt_collect_0_ref
 174     // fold_{N}_{T} processes N arguments at any position into a T value, which it inserts
 175     // fold_{T} processes any number of arguments at any position
 176     _adapter_opt_fold_ref,       // process N arguments, prepend a reference
 177     _adapter_opt_fold_int,       // process N arguments, prepend an int, short, etc.
 178     _adapter_opt_fold_long,      // process N arguments, prepend a long
 179     _adapter_opt_fold_float,     // process N arguments, prepend a float
 180     _adapter_opt_fold_double,    // process N arguments, prepend a double
 181     _adapter_opt_fold_void,      // process N arguments, but leave the list unchanged
 182     _adapter_opt_fold_1_ref,     // process N=1 argument, prepend a reference
 183     _adapter_opt_fold_2_ref,     // process N=2 arguments, prepend a reference
 184     _adapter_opt_fold_3_ref,     // process N=3 arguments, prepend a reference
 185     _adapter_opt_fold_4_ref,     // process N=4 arguments, prepend a reference
 186     _adapter_opt_fold_5_ref,     // process N=5 arguments, prepend a reference
 187     _adapter_opt_fold_FIRST = _adapter_opt_fold_ref,
 188     _adapter_opt_fold_LAST  = _adapter_opt_fold_5_ref,
 189 
 190     _adapter_opt_profiling,
 191 
 192     _EK_LIMIT,
 193     _EK_FIRST = 0
 194   };
 195 
 196  public:
 197   static bool enabled()                         { return _enabled; }
 198   static void set_enabled(bool z);
 199 
 200  private:
 201   enum {  // import java_lang_invoke_AdapterMethodHandle::CONV_OP_*
 202     CONV_OP_LIMIT         = java_lang_invoke_AdapterMethodHandle::CONV_OP_LIMIT,
 203     CONV_OP_MASK          = java_lang_invoke_AdapterMethodHandle::CONV_OP_MASK,
 204     CONV_TYPE_MASK        = java_lang_invoke_AdapterMethodHandle::CONV_TYPE_MASK,
 205     CONV_VMINFO_MASK      = java_lang_invoke_AdapterMethodHandle::CONV_VMINFO_MASK,
 206     CONV_VMINFO_SHIFT     = java_lang_invoke_AdapterMethodHandle::CONV_VMINFO_SHIFT,
 207     CONV_OP_SHIFT         = java_lang_invoke_AdapterMethodHandle::CONV_OP_SHIFT,
 208     CONV_DEST_TYPE_SHIFT  = java_lang_invoke_AdapterMethodHandle::CONV_DEST_TYPE_SHIFT,
 209     CONV_SRC_TYPE_SHIFT   = java_lang_invoke_AdapterMethodHandle::CONV_SRC_TYPE_SHIFT,
 210     CONV_STACK_MOVE_SHIFT = java_lang_invoke_AdapterMethodHandle::CONV_STACK_MOVE_SHIFT,
 211     CONV_STACK_MOVE_MASK  = java_lang_invoke_AdapterMethodHandle::CONV_STACK_MOVE_MASK
 212   };
 213 
 214   static bool _enabled;
 215   static MethodHandleEntry* _entries[_EK_LIMIT];
 216   static const char*        _entry_names[_EK_LIMIT+1];
 217   static jobject            _raise_exception_method;
 218   static address            _adapter_return_handlers[CONV_TYPE_MASK+1];
 219 
 220   // Adapters.
 221   static MethodHandlesAdapterBlob* _adapter_code;
 222 
 223   static bool ek_valid(EntryKind ek)            { return (uint)ek < (uint)_EK_LIMIT; }
 224   static bool conv_op_valid(int op)             { return (uint)op < (uint)CONV_OP_LIMIT; }
 225 
 226  public:
 227   static bool    have_entry(EntryKind ek)       { return ek_valid(ek) && _entries[ek] != NULL; }
 228   static MethodHandleEntry* entry(EntryKind ek) { assert(ek_valid(ek), "initialized");
 229                                                   return _entries[ek]; }
 230   static const char* entry_name(EntryKind ek)   { assert(ek_valid(ek), "oob");
 231                                                   return _entry_names[ek]; }
 232   static EntryKind adapter_entry_kind(int op)   { assert(conv_op_valid(op), "oob");
 233                                                   return EntryKind(_adapter_mh_first + op); }
 234 
 235   static void init_entry(EntryKind ek, MethodHandleEntry* me) {
 236     assert(ek_valid(ek), "oob");
 237     assert(_entries[ek] == NULL, "no double initialization");
 238     _entries[ek] = me;
 239   }
 240 
 241   // Some adapter helper functions.
 242   static EntryKind ek_original_kind(EntryKind ek) {
 243     if (ek <= _adapter_mh_last)  return ek;
 244     switch (ek) {
 245     case _adapter_opt_swap_1:
 246     case _adapter_opt_swap_2:
 247       return _adapter_swap_args;
 248     case _adapter_opt_rot_1_up:
 249     case _adapter_opt_rot_1_down:
 250     case _adapter_opt_rot_2_up:
 251     case _adapter_opt_rot_2_down:
 252       return _adapter_rot_args;
 253     case _adapter_opt_i2i:
 254     case _adapter_opt_l2i:
 255     case _adapter_opt_d2f:
 256     case _adapter_opt_i2l:
 257     case _adapter_opt_f2d:
 258       return _adapter_prim_to_prim;
 259     case _adapter_opt_unboxi:
 260     case _adapter_opt_unboxl:
 261       return _adapter_ref_to_prim;
 262     }
 263     if (ek >= _adapter_opt_spread_FIRST && ek <= _adapter_opt_spread_LAST)
 264       return _adapter_spread_args;
 265     if (ek >= _adapter_opt_collect_FIRST && ek <= _adapter_opt_collect_LAST)
 266       return _adapter_collect_args;
 267     if (ek >= _adapter_opt_fold_FIRST && ek <= _adapter_opt_fold_LAST)
 268       return _adapter_fold_args;
 269     if (ek >= _adapter_opt_return_FIRST && ek <= _adapter_opt_return_LAST)
 270       return _adapter_opt_return_any;
 271     if (ek == _adapter_opt_profiling)
 272       return _adapter_retype_only;
 273     assert(false, "oob");
 274     return _EK_LIMIT;
 275   }
 276 
 277   static bool ek_supported(MethodHandles::EntryKind ek);
 278 
 279   static BasicType ek_bound_mh_arg_type(EntryKind ek) {
 280     switch (ek) {
 281     case _bound_int_mh         : // fall-thru
 282     case _bound_int_direct_mh  : return T_INT;
 283     case _bound_long_mh        : // fall-thru
 284     case _bound_long_direct_mh : return T_LONG;
 285     default                    : return T_OBJECT;
 286     }
 287   }
 288 
 289   static int ek_adapter_opt_swap_slots(EntryKind ek) {
 290     switch (ek) {
 291     case _adapter_opt_swap_1        : return  1;
 292     case _adapter_opt_swap_2        : return  2;
 293     case _adapter_opt_rot_1_up      : return  1;
 294     case _adapter_opt_rot_1_down    : return  1;
 295     case _adapter_opt_rot_2_up      : return  2;
 296     case _adapter_opt_rot_2_down    : return  2;
 297     default : ShouldNotReachHere();   return -1;
 298     }
 299   }
 300 
 301   static int ek_adapter_opt_swap_mode(EntryKind ek) {
 302     switch (ek) {
 303     case _adapter_opt_swap_1       : return  0;
 304     case _adapter_opt_swap_2       : return  0;
 305     case _adapter_opt_rot_1_up     : return  1;
 306     case _adapter_opt_rot_1_down   : return -1;
 307     case _adapter_opt_rot_2_up     : return  1;
 308     case _adapter_opt_rot_2_down   : return -1;
 309     default : ShouldNotReachHere();  return  0;
 310     }
 311   }
 312 
 313   static int ek_adapter_opt_collect_count(EntryKind ek) {
 314     assert(ek >= _adapter_opt_collect_FIRST && ek <= _adapter_opt_collect_LAST ||
 315            ek >= _adapter_opt_fold_FIRST    && ek <= _adapter_opt_fold_LAST, "");
 316     switch (ek) {
 317     case _adapter_opt_collect_0_ref    : return  0;
 318     case _adapter_opt_filter_S0_ref    :
 319     case _adapter_opt_filter_S1_ref    :
 320     case _adapter_opt_filter_S2_ref    :
 321     case _adapter_opt_filter_S3_ref    :
 322     case _adapter_opt_filter_S4_ref    :
 323     case _adapter_opt_filter_S5_ref    :
 324     case _adapter_opt_fold_1_ref       :
 325     case _adapter_opt_collect_1_ref    : return  1;
 326     case _adapter_opt_collect_2_S0_ref :
 327     case _adapter_opt_collect_2_S1_ref :
 328     case _adapter_opt_collect_2_S2_ref :
 329     case _adapter_opt_collect_2_S3_ref :
 330     case _adapter_opt_collect_2_S4_ref :
 331     case _adapter_opt_collect_2_S5_ref :
 332     case _adapter_opt_fold_2_ref       :
 333     case _adapter_opt_collect_2_ref    : return  2;
 334     case _adapter_opt_fold_3_ref       :
 335     case _adapter_opt_collect_3_ref    : return  3;
 336     case _adapter_opt_fold_4_ref       :
 337     case _adapter_opt_collect_4_ref    : return  4;
 338     case _adapter_opt_fold_5_ref       :
 339     case _adapter_opt_collect_5_ref    : return  5;
 340     default                            : return -1;  // sentinel value for "variable"
 341     }
 342   }
 343 
 344   static int ek_adapter_opt_collect_slot(EntryKind ek) {
 345     assert(ek >= _adapter_opt_collect_FIRST && ek <= _adapter_opt_collect_LAST ||
 346            ek >= _adapter_opt_fold_FIRST    && ek <= _adapter_opt_fold_LAST, "");
 347     switch (ek) {
 348     case _adapter_opt_collect_2_S0_ref  :
 349     case _adapter_opt_filter_S0_ref     : return 0;
 350     case _adapter_opt_collect_2_S1_ref  :
 351     case _adapter_opt_filter_S1_ref     : return 1;
 352     case _adapter_opt_collect_2_S2_ref  :
 353     case _adapter_opt_filter_S2_ref     : return 2;
 354     case _adapter_opt_collect_2_S3_ref  :
 355     case _adapter_opt_filter_S3_ref     : return 3;
 356     case _adapter_opt_collect_2_S4_ref  :
 357     case _adapter_opt_filter_S4_ref     : return 4;
 358     case _adapter_opt_collect_2_S5_ref  :
 359     case _adapter_opt_filter_S5_ref     : return 5;
 360     default                             : return -1;  // sentinel value for "variable"
 361     }
 362   }
 363 
 364   static BasicType ek_adapter_opt_collect_type(EntryKind ek) {
 365     assert(ek >= _adapter_opt_collect_FIRST && ek <= _adapter_opt_collect_LAST ||
 366            ek >= _adapter_opt_fold_FIRST    && ek <= _adapter_opt_fold_LAST, "");
 367     switch (ek) {
 368     case _adapter_opt_fold_int          :
 369     case _adapter_opt_collect_int       : return T_INT;
 370     case _adapter_opt_fold_long         :
 371     case _adapter_opt_collect_long      : return T_LONG;
 372     case _adapter_opt_fold_float        :
 373     case _adapter_opt_collect_float     : return T_FLOAT;
 374     case _adapter_opt_fold_double       :
 375     case _adapter_opt_collect_double    : return T_DOUBLE;
 376     case _adapter_opt_fold_void         :
 377     case _adapter_opt_collect_void      : return T_VOID;
 378     default                             : return T_OBJECT;
 379     }
 380   }
 381 
 382   static int ek_adapter_opt_return_slot(EntryKind ek) {
 383     assert(ek >= _adapter_opt_return_FIRST && ek <= _adapter_opt_return_LAST, "");
 384     switch (ek) {
 385     case _adapter_opt_return_S0_ref : return 0;
 386     case _adapter_opt_return_S1_ref : return 1;
 387     case _adapter_opt_return_S2_ref : return 2;
 388     case _adapter_opt_return_S3_ref : return 3;
 389     case _adapter_opt_return_S4_ref : return 4;
 390     case _adapter_opt_return_S5_ref : return 5;
 391     default                         : return -1;  // sentinel value for "variable"
 392     }
 393   }
 394 
 395   static BasicType ek_adapter_opt_return_type(EntryKind ek) {
 396     assert(ek >= _adapter_opt_return_FIRST && ek <= _adapter_opt_return_LAST, "");
 397     switch (ek) {
 398     case _adapter_opt_return_int    : return T_INT;
 399     case _adapter_opt_return_long   : return T_LONG;
 400     case _adapter_opt_return_float  : return T_FLOAT;
 401     case _adapter_opt_return_double : return T_DOUBLE;
 402     case _adapter_opt_return_void   : return T_VOID;
 403     case _adapter_opt_return_any    : return T_CONFLICT;  // sentinel value for "variable"
 404     default                         : return T_OBJECT;
 405     }
 406   }
 407 
 408   static int ek_adapter_opt_spread_count(EntryKind ek) {
 409     assert(ek >= _adapter_opt_spread_FIRST && ek <= _adapter_opt_spread_LAST, "");
 410     switch (ek) {
 411     case _adapter_opt_spread_0     : return  0;
 412     case _adapter_opt_spread_1_ref : return  1;
 413     case _adapter_opt_spread_2_ref : return  2;
 414     case _adapter_opt_spread_3_ref : return  3;
 415     case _adapter_opt_spread_4_ref : return  4;
 416     case _adapter_opt_spread_5_ref : return  5;
 417     default                        : return -1;  // sentinel value for "variable"
 418     }
 419   }
 420 
 421   static BasicType ek_adapter_opt_spread_type(EntryKind ek) {
 422     assert(ek >= _adapter_opt_spread_FIRST && ek <= _adapter_opt_spread_LAST, "");
 423     switch (ek) {
 424     // (there is no _adapter_opt_spread_boolean; we use byte)
 425     case _adapter_opt_spread_byte   : return T_BYTE;
 426     case _adapter_opt_spread_char   : return T_CHAR;
 427     case _adapter_opt_spread_short  : return T_SHORT;
 428     case _adapter_opt_spread_int    : return T_INT;
 429     case _adapter_opt_spread_long   : return T_LONG;
 430     case _adapter_opt_spread_float  : return T_FLOAT;
 431     case _adapter_opt_spread_double : return T_DOUBLE;
 432     default                         : return T_OBJECT;
 433     }
 434   }
 435 
 436   static methodOop raise_exception_method() {
 437     oop rem = JNIHandles::resolve(_raise_exception_method);
 438     assert(rem == NULL || rem->is_method(), "");
 439     return (methodOop) rem;
 440   }
 441   static void set_raise_exception_method(methodOop rem) {
 442     assert(_raise_exception_method == NULL, "");
 443     _raise_exception_method = JNIHandles::make_global(Handle(rem));
 444   }
 445   static methodOop resolve_raise_exception_method(TRAPS);
 446   // call raise_exception_method from C code:
 447   static void raise_exception(int code, oop actual, oop required, TRAPS);
 448 
 449   static jint adapter_conversion(int conv_op, BasicType src, BasicType dest,
 450                                  int stack_move = 0, int vminfo = 0) {
 451     assert(conv_op_valid(conv_op), "oob");
 452     jint conv = ((conv_op      << CONV_OP_SHIFT)
 453                  | (src        << CONV_SRC_TYPE_SHIFT)
 454                  | (dest       << CONV_DEST_TYPE_SHIFT)
 455                  | (stack_move << CONV_STACK_MOVE_SHIFT)
 456                  | (vminfo     << CONV_VMINFO_SHIFT)
 457                  );
 458     assert(adapter_conversion_op(conv) == conv_op, "decode conv_op");
 459     assert(adapter_conversion_src_type(conv) == src, "decode src");
 460     assert(adapter_conversion_dest_type(conv) == dest, "decode dest");
 461     assert(adapter_conversion_stack_move(conv) == stack_move, "decode stack_move");
 462     assert(adapter_conversion_vminfo(conv) == vminfo, "decode vminfo");
 463     return conv;
 464   }
 465   static int adapter_conversion_op(jint conv) {
 466     return ((conv >> CONV_OP_SHIFT) & 0xF);
 467   }
 468   static BasicType adapter_conversion_src_type(jint conv) {
 469     return (BasicType)((conv >> CONV_SRC_TYPE_SHIFT) & 0xF);
 470   }
 471   static BasicType adapter_conversion_dest_type(jint conv) {
 472     return (BasicType)((conv >> CONV_DEST_TYPE_SHIFT) & 0xF);
 473   }
 474   static int adapter_conversion_stack_move(jint conv) {
 475     return (conv >> CONV_STACK_MOVE_SHIFT);
 476   }
 477   static int adapter_conversion_vminfo(jint conv) {
 478     return (conv >> CONV_VMINFO_SHIFT) & CONV_VMINFO_MASK;
 479   }
 480 
 481   // Bit mask of conversion_op values.  May vary by platform.
 482   static int adapter_conversion_ops_supported_mask();
 483 
 484   static bool conv_op_supported(int conv_op) {
 485     assert(conv_op_valid(conv_op), "");
 486     return ((adapter_conversion_ops_supported_mask() & nth_bit(conv_op)) != 0);
 487   }
 488 
 489   // Offset in words that the interpreter stack pointer moves when an argument is pushed.
 490   // The stack_move value must always be a multiple of this.
 491   static int stack_move_unit() {
 492     return frame::interpreter_frame_expression_stack_direction() * Interpreter::stackElementWords;
 493   }
 494 
 495   // Adapter frame traversal.  (Implementation-specific.)
 496   static frame ricochet_frame_sender(const frame& fr, RegisterMap* reg_map);
 497   static void ricochet_frame_oops_do(const frame& fr, OopClosure* blk, const RegisterMap* reg_map);
 498 
 499   enum { CONV_VMINFO_SIGN_FLAG = 0x80 };
 500   // Shift values for prim-to-prim conversions.
 501   static int adapter_prim_to_prim_subword_vminfo(BasicType dest) {
 502     if (dest == T_BOOLEAN) return (BitsPerInt - 1);  // boolean is 1 bit
 503     if (dest == T_CHAR)    return (BitsPerInt - BitsPerShort);
 504     if (dest == T_BYTE)    return (BitsPerInt - BitsPerByte ) | CONV_VMINFO_SIGN_FLAG;
 505     if (dest == T_SHORT)   return (BitsPerInt - BitsPerShort) | CONV_VMINFO_SIGN_FLAG;
 506     return 0;                   // case T_INT
 507   }
 508   // Shift values for unboxing a primitive.
 509   static int adapter_unbox_subword_vminfo(BasicType dest) {
 510     if (dest == T_BOOLEAN) return (BitsPerInt - BitsPerByte );  // implemented as 1 byte
 511     if (dest == T_CHAR)    return (BitsPerInt - BitsPerShort);
 512     if (dest == T_BYTE)    return (BitsPerInt - BitsPerByte ) | CONV_VMINFO_SIGN_FLAG;
 513     if (dest == T_SHORT)   return (BitsPerInt - BitsPerShort) | CONV_VMINFO_SIGN_FLAG;
 514     return 0;                   // case T_INT
 515   }
 516   // Here is the transformation the i2i adapter must perform:
 517   static int truncate_subword_from_vminfo(jint value, int vminfo) {
 518     jint tem = value << vminfo;
 519     if ((vminfo & CONV_VMINFO_SIGN_FLAG) != 0) {
 520       return (jint)tem >> vminfo;
 521     } else {
 522       return (juint)tem >> vminfo;
 523     }
 524   }
 525 
 526   static inline address from_compiled_entry(EntryKind ek);
 527   static inline address from_interpreted_entry(EntryKind ek);
 528 
 529   // helpers for decode_method.
 530   static methodOop    decode_methodOop(methodOop m, int& decode_flags_result);
 531   static methodHandle decode_vmtarget(oop vmtarget, int vmindex, oop mtype, KlassHandle& receiver_limit_result, int& decode_flags_result);
 532   static methodHandle decode_MemberName(oop mname, KlassHandle& receiver_limit_result, int& decode_flags_result);
 533   static methodHandle decode_MethodHandle(oop mh, KlassHandle& receiver_limit_result, int& decode_flags_result);
 534   static methodHandle decode_DirectMethodHandle(oop mh, KlassHandle& receiver_limit_result, int& decode_flags_result);
 535   static methodHandle decode_BoundMethodHandle(oop mh, KlassHandle& receiver_limit_result, int& decode_flags_result);
 536   static methodHandle decode_AdapterMethodHandle(oop mh, KlassHandle& receiver_limit_result, int& decode_flags_result);
 537 
 538   // Find out how many stack slots an mh pushes or pops.
 539   // The result is *not* reported as a multiple of stack_move_unit();
 540   // It is a signed net number of pushes (a difference in vmslots).
 541   // To compare with a stack_move value, first multiply by stack_move_unit().
 542   static int decode_MethodHandle_stack_pushes(oop mh);
 543 
 544  public:
 545   // working with member names
 546   static void resolve_MemberName(Handle mname, TRAPS); // compute vmtarget/vmindex from name/type
 547   static void expand_MemberName(Handle mname, int suppress, TRAPS);  // expand defc/name/type if missing
 548   static Handle new_MemberName(TRAPS);  // must be followed by init_MemberName
 549   static void init_MemberName(oop mname_oop, oop target); // compute vmtarget/vmindex from target
 550   static void init_MemberName(oop mname_oop, methodOop m, bool do_dispatch = true);
 551   static void init_MemberName(oop mname_oop, klassOop field_holder, AccessFlags mods, int offset);
 552   static int find_MemberNames(klassOop k, Symbol* name, Symbol* sig,
 553                               int mflags, klassOop caller,
 554                               int skip, objArrayOop results);
 555   // bit values for suppress argument to expand_MemberName:
 556   enum { _suppress_defc = 1, _suppress_name = 2, _suppress_type = 4 };
 557 
 558   // Generate MethodHandles adapters.
 559   static void generate_adapters();
 560 
 561   // Called from InterpreterGenerator and MethodHandlesAdapterGenerator.
 562   static address generate_method_handle_interpreter_entry(MacroAssembler* _masm);
 563   static void generate_method_handle_stub(MacroAssembler* _masm, EntryKind ek);
 564 
 565   // argument list parsing
 566   static int argument_slot(oop method_type, int arg);
 567   static int argument_slot_count(oop method_type) { return argument_slot(method_type, -1); }
 568   static int argument_slot_to_argnum(oop method_type, int argslot);
 569 
 570   // Runtime support
 571   enum {                        // bit-encoded flags from decode_method or decode_vmref
 572     _dmf_has_receiver   = 0x01, // target method has leading reference argument
 573     _dmf_does_dispatch  = 0x02, // method handle performs virtual or interface dispatch
 574     _dmf_from_interface = 0x04, // peforms interface dispatch
 575     _DMF_DIRECT_MASK    = (_dmf_from_interface*2 - _dmf_has_receiver),
 576     _dmf_binds_method   = 0x08,
 577     _dmf_binds_argument = 0x10,
 578     _DMF_BOUND_MASK     = (_dmf_binds_argument*2 - _dmf_binds_method),
 579     _dmf_adapter_lsb    = 0x20,
 580     _DMF_ADAPTER_MASK   = (_dmf_adapter_lsb << CONV_OP_LIMIT) - _dmf_adapter_lsb
 581   };
 582   static methodHandle decode_method(oop x, KlassHandle& receiver_limit_result, int& decode_flags_result);
 583   enum {
 584     // format of query to getConstant:
 585     GC_JVM_PUSH_LIMIT = 0,
 586     GC_JVM_STACK_MOVE_UNIT = 1,
 587     GC_CONV_OP_IMPLEMENTED_MASK = 2,
 588     GC_OP_ROT_ARGS_DOWN_LIMIT_BIAS = 3,
 589     GC_COUNT_GWT = 4,
 590 
 591     // format of result from getTarget / encode_target:
 592     ETF_HANDLE_OR_METHOD_NAME = 0, // all available data (immediate MH or method)
 593     ETF_DIRECT_HANDLE         = 1, // ultimate method handle (will be a DMH, may be self)
 594     ETF_METHOD_NAME           = 2, // ultimate method as MemberName
 595     ETF_REFLECT_METHOD        = 3, // ultimate method as java.lang.reflect object (sans refClass)
 596     ETF_FORCE_DIRECT_HANDLE   = 64,
 597     ETF_COMPILE_DIRECT_HANDLE = 65,
 598 
 599     // ad hoc constants
 600     OP_ROT_ARGS_DOWN_LIMIT_BIAS = -1
 601   };
 602   static int get_named_constant(int which, Handle name_box, TRAPS);
 603   static oop encode_target(Handle mh, int format, TRAPS); // report vmtarget (to Java code)
 604   static bool class_cast_needed(klassOop src, klassOop dst);
 605 
 606   static instanceKlassHandle resolve_instance_klass(oop    java_mirror_oop, TRAPS);
 607   static instanceKlassHandle resolve_instance_klass(jclass java_mirror_jh,  TRAPS) {
 608     return resolve_instance_klass(JNIHandles::resolve(java_mirror_jh), THREAD);
 609   }
 610 
 611  private:
 612   // These checkers operate on a pair of whole MethodTypes:
 613   static const char* check_method_type_change(oop src_mtype, int src_beg, int src_end,
 614                                               int insert_argnum, oop insert_type,
 615                                               int change_argnum, oop change_type,
 616                                               int delete_argnum,
 617                                               oop dst_mtype, int dst_beg, int dst_end,
 618                                               bool raw = false);
 619   static const char* check_method_type_insertion(oop src_mtype,
 620                                                  int insert_argnum, oop insert_type,
 621                                                  oop dst_mtype) {
 622     oop no_ref = NULL;
 623     return check_method_type_change(src_mtype, 0, -1,
 624                                     insert_argnum, insert_type,
 625                                     -1, no_ref, -1, dst_mtype, 0, -1);
 626   }
 627   static const char* check_method_type_conversion(oop src_mtype,
 628                                                   int change_argnum, oop change_type,
 629                                                   oop dst_mtype) {
 630     oop no_ref = NULL;
 631     return check_method_type_change(src_mtype, 0, -1, -1, no_ref,
 632                                     change_argnum, change_type,
 633                                     -1, dst_mtype, 0, -1);
 634   }
 635   static const char* check_method_type_passthrough(oop src_mtype, oop dst_mtype, bool raw) {
 636     oop no_ref = NULL;
 637     return check_method_type_change(src_mtype, 0, -1,
 638                                     -1, no_ref, -1, no_ref, -1,
 639                                     dst_mtype, 0, -1, raw);
 640   }
 641 
 642   // These checkers operate on pairs of argument or return types:
 643   static const char* check_argument_type_change(BasicType src_type, klassOop src_klass,
 644                                                 BasicType dst_type, klassOop dst_klass,
 645                                                 int argnum, bool raw = false);
 646 
 647   static const char* check_argument_type_change(oop src_type, oop dst_type,
 648                                                 int argnum, bool raw = false) {
 649     klassOop src_klass = NULL, dst_klass = NULL;
 650     BasicType src_bt = java_lang_Class::as_BasicType(src_type, &src_klass);
 651     BasicType dst_bt = java_lang_Class::as_BasicType(dst_type, &dst_klass);
 652     return check_argument_type_change(src_bt, src_klass,
 653                                       dst_bt, dst_klass, argnum, raw);
 654   }
 655 
 656   static const char* check_return_type_change(oop src_type, oop dst_type, bool raw = false) {
 657     return check_argument_type_change(src_type, dst_type, -1, raw);
 658   }
 659 
 660   static const char* check_return_type_change(BasicType src_type, klassOop src_klass,
 661                                               BasicType dst_type, klassOop dst_klass) {
 662     return check_argument_type_change(src_type, src_klass, dst_type, dst_klass, -1);
 663   }
 664 
 665   static const char* check_method_receiver(methodOop m, klassOop passed_recv_type);
 666 
 667   // These verifiers can block, and will throw an error if the checking fails:
 668   static void verify_vmslots(Handle mh, TRAPS);
 669   static void verify_vmargslot(Handle mh, int argnum, int argslot, TRAPS);
 670 
 671   static void verify_method_type(methodHandle m, Handle mtype,
 672                                  bool has_bound_oop,
 673                                  KlassHandle bound_oop_type,
 674                                  TRAPS);
 675 
 676   static void verify_method_signature(methodHandle m, Handle mtype,
 677                                       int first_ptype_pos,
 678                                       KlassHandle insert_ptype, TRAPS);
 679 
 680   static void verify_DirectMethodHandle(Handle mh, methodHandle m, TRAPS);
 681   static void verify_BoundMethodHandle(Handle mh, Handle target, int argnum,
 682                                        bool direct_to_method, TRAPS);
 683   static void verify_BoundMethodHandle_with_receiver(Handle mh, methodHandle m, TRAPS);
 684   static void verify_AdapterMethodHandle(Handle mh, int argnum, TRAPS);
 685 
 686  public:
 687 
 688   // Fill in the fields of a DirectMethodHandle mh.  (MH.type must be pre-filled.)
 689   static void init_DirectMethodHandle(Handle mh, methodHandle method, bool do_dispatch, TRAPS);
 690 
 691   // Fill in the fields of a BoundMethodHandle mh.  (MH.type, BMH.argument must be pre-filled.)
 692   static void init_BoundMethodHandle(Handle mh, Handle target, int argnum, TRAPS);
 693   static void init_BoundMethodHandle_with_receiver(Handle mh,
 694                                                    methodHandle original_m,
 695                                                    KlassHandle receiver_limit,
 696                                                    int decode_flags,
 697                                                    TRAPS);
 698 
 699   // Fill in the fields of an AdapterMethodHandle mh.  (MH.type must be pre-filled.)
 700   static void init_AdapterMethodHandle(Handle mh, Handle target, int argnum, TRAPS);
 701   static void ensure_vmlayout_field(Handle target, TRAPS);
 702 
 703 #ifdef ASSERT
 704   static bool spot_check_entry_names();
 705 #endif
 706 
 707  private:
 708   static methodHandle dispatch_decoded_method(methodHandle m,
 709                                               KlassHandle receiver_limit,
 710                                               int decode_flags,
 711                                               KlassHandle receiver_klass,
 712                                               TRAPS);
 713 
 714 public:
 715   static bool is_float_fixed_reinterpretation_cast(BasicType src, BasicType dst);
 716   static bool same_basic_type_for_arguments(BasicType src, BasicType dst,
 717                                             bool raw = false,
 718                                             bool for_return = false);
 719   static bool same_basic_type_for_returns(BasicType src, BasicType dst, bool raw = false) {
 720     return same_basic_type_for_arguments(src, dst, raw, true);
 721   }
 722 
 723   static Symbol* convert_to_signature(oop type_str, bool polymorphic, TRAPS);
 724 
 725 #ifdef TARGET_ARCH_x86
 726 # include "methodHandles_x86.hpp"
 727 #endif
 728 #ifdef TARGET_ARCH_sparc
 729 # include "methodHandles_sparc.hpp"
 730 #endif
 731 #ifdef TARGET_ARCH_zero
 732 # include "methodHandles_zero.hpp"
 733 #endif
 734 #ifdef TARGET_ARCH_arm
 735 # include "methodHandles_arm.hpp"
 736 #endif
 737 #ifdef TARGET_ARCH_ppc
 738 # include "methodHandles_ppc.hpp"
 739 #endif
 740 
 741 #ifdef TARGET_ARCH_NYI_6939861
 742   // Here are some backward compatible declarations until the 6939861 ports are updated.
 743   #define _adapter_flyby    (_EK_LIMIT + 10)
 744   #define _adapter_ricochet (_EK_LIMIT + 11)
 745   #define _adapter_opt_spread_1    _adapter_opt_spread_1_ref
 746   #define _adapter_opt_spread_more _adapter_opt_spread_ref
 747   enum {
 748     _INSERT_NO_MASK   = -1,
 749     _INSERT_REF_MASK  = 0,
 750     _INSERT_INT_MASK  = 1,
 751     _INSERT_LONG_MASK = 3
 752   };
 753   static void get_ek_bound_mh_info(EntryKind ek, BasicType& arg_type, int& arg_mask, int& arg_slots) {
 754     arg_type = ek_bound_mh_arg_type(ek);
 755     arg_mask = 0;
 756     arg_slots = type2size[arg_type];;
 757   }
 758   static void get_ek_adapter_opt_swap_rot_info(EntryKind ek, int& swap_bytes, int& rotate) {
 759     int swap_slots = ek_adapter_opt_swap_slots(ek);
 760     rotate = ek_adapter_opt_swap_mode(ek);
 761     swap_bytes = swap_slots * Interpreter::stackElementSize;
 762   }
 763   static int get_ek_adapter_opt_spread_info(EntryKind ek) {
 764     return ek_adapter_opt_spread_count(ek);
 765   }
 766 
 767   static void insert_arg_slots(MacroAssembler* _masm,
 768                                RegisterOrConstant arg_slots,
 769                                int arg_mask,
 770                                Register argslot_reg,
 771                                Register temp_reg, Register temp2_reg, Register temp3_reg = noreg);
 772 
 773   static void remove_arg_slots(MacroAssembler* _masm,
 774                                RegisterOrConstant arg_slots,
 775                                Register argslot_reg,
 776                                Register temp_reg, Register temp2_reg, Register temp3_reg = noreg);
 777 
 778   static void trace_method_handle(MacroAssembler* _masm, const char* adaptername) PRODUCT_RETURN;
 779 #endif //TARGET_ARCH_NYI_6939861
 780 };
 781 
 782 
 783 // Access methods for the "entry" field of a java.lang.invoke.MethodHandle.
 784 // The field is primarily a jump target for compiled calls.
 785 // However, we squirrel away some nice pointers for other uses,
 786 // just before the jump target.
 787 // Aspects of a method handle entry:
 788 //  - from_compiled_entry - stub used when compiled code calls the MH
 789 //  - from_interpreted_entry - stub used when the interpreter calls the MH
 790 //  - type_checking_entry - stub for runtime casting between MHForm siblings (NYI)
 791 class MethodHandleEntry {
 792  public:
 793   class Data {
 794     friend class MethodHandleEntry;
 795     size_t              _total_size; // size including Data and code stub
 796     MethodHandleEntry*  _type_checking_entry;
 797     address             _from_interpreted_entry;
 798     MethodHandleEntry* method_entry() { return (MethodHandleEntry*)(this + 1); }
 799   };
 800 
 801   Data*     data()                              { return (Data*)this - 1; }
 802 
 803   address   start_address()                     { return (address) data(); }
 804   address   end_address()                       { return start_address() + data()->_total_size; }
 805 
 806   address   from_compiled_entry()               { return (address) this; }
 807 
 808   address   from_interpreted_entry()            { return data()->_from_interpreted_entry; }
 809   void  set_from_interpreted_entry(address e)   { data()->_from_interpreted_entry = e; }
 810 
 811   MethodHandleEntry* type_checking_entry()           { return data()->_type_checking_entry; }
 812   void set_type_checking_entry(MethodHandleEntry* e) { data()->_type_checking_entry = e; }
 813 
 814   void set_end_address(address end_addr) {
 815     size_t total_size = end_addr - start_address();
 816     assert(total_size > 0 && total_size < 0x1000, "reasonable end address");
 817     data()->_total_size = total_size;
 818   }
 819 
 820   // Compiler support:
 821   static int from_interpreted_entry_offset_in_bytes() {
 822     return (int)( offset_of(Data, _from_interpreted_entry) - sizeof(Data) );
 823   }
 824   static int type_checking_entry_offset_in_bytes() {
 825     return (int)( offset_of(Data, _from_interpreted_entry) - sizeof(Data) );
 826   }
 827 
 828   static address            start_compiled_entry(MacroAssembler* _masm,
 829                                                  address interpreted_entry = NULL);
 830   static MethodHandleEntry* finish_compiled_entry(MacroAssembler* masm, address start_addr);
 831 };
 832 
 833 address MethodHandles::from_compiled_entry(EntryKind ek) { return entry(ek)->from_compiled_entry(); }
 834 address MethodHandles::from_interpreted_entry(EntryKind ek) { return entry(ek)->from_interpreted_entry(); }
 835 
 836 
 837 //------------------------------------------------------------------------------
 838 // MethodHandlesAdapterGenerator
 839 //
 840 class MethodHandlesAdapterGenerator : public StubCodeGenerator {
 841 public:
 842   MethodHandlesAdapterGenerator(CodeBuffer* code) : StubCodeGenerator(code, PrintMethodHandleStubs) {}
 843 
 844   void generate();
 845 };
 846 
 847 #endif // SHARE_VM_PRIMS_METHODHANDLES_HPP