1 /*
   2  * Copyright (c) 2008, 2013, 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 #include "precompiled.hpp"
  26 #include "asm/macroAssembler.hpp"
  27 #include "interpreter/interpreter.hpp"
  28 #include "memory/allocation.inline.hpp"
  29 #include "prims/methodHandles.hpp"
  30 
  31 #define __ _masm->
  32 
  33 #ifdef PRODUCT
  34 #define BLOCK_COMMENT(str) /* nothing */
  35 #define STOP(error) stop(error)
  36 #else
  37 #define BLOCK_COMMENT(str) __ block_comment(str)
  38 #define STOP(error) block_comment(error); __ stop(error)
  39 #endif
  40 
  41 #define BIND(label) bind(label); BLOCK_COMMENT(#label ":")
  42 
  43 // Workaround for C++ overloading nastiness on '0' for RegisterOrConstant.
  44 static RegisterOrConstant constant(int value) {
  45   return RegisterOrConstant(value);
  46 }
  47 
  48 void MethodHandles::load_klass_from_Class(MacroAssembler* _masm, Register klass_reg, Register temp_reg, Register temp2_reg) {
  49   if (VerifyMethodHandles)
  50     verify_klass(_masm, klass_reg, SystemDictionary::WK_KLASS_ENUM_NAME(java_lang_Class), temp_reg, temp2_reg,
  51                  "MH argument is a Class");
  52   __ ld_ptr(Address(klass_reg, java_lang_Class::klass_offset_in_bytes()), klass_reg);
  53 }
  54 
  55 #ifdef ASSERT
  56 static int check_nonzero(const char* xname, int x) {
  57   assert(x != 0, err_msg("%s should be nonzero", xname));
  58   return x;
  59 }
  60 #define NONZERO(x) check_nonzero(#x, x)
  61 #else //ASSERT
  62 #define NONZERO(x) (x)
  63 #endif //ASSERT
  64 
  65 #ifdef ASSERT
  66 void MethodHandles::verify_klass(MacroAssembler* _masm,
  67                                  Register obj_reg, SystemDictionary::WKID klass_id,
  68                                  Register temp_reg, Register temp2_reg,
  69                                  const char* error_message) {
  70   Klass** klass_addr = SystemDictionary::well_known_klass_addr(klass_id);
  71   KlassHandle klass = SystemDictionary::well_known_klass(klass_id);
  72   bool did_save = false;
  73   if (temp_reg == noreg || temp2_reg == noreg) {
  74     temp_reg = L1;
  75     temp2_reg = L2;
  76     __ save_frame_and_mov(0, obj_reg, L0);
  77     obj_reg = L0;
  78     did_save = true;
  79   }
  80   Label L_ok, L_bad;
  81   BLOCK_COMMENT("verify_klass {");
  82   __ verify_oop(obj_reg);
  83   __ br_null_short(obj_reg, Assembler::pn, L_bad);
  84   __ load_klass(obj_reg, temp_reg);
  85   __ set(ExternalAddress((Metadata**)klass_addr), temp2_reg);
  86   __ ld_ptr(Address(temp2_reg, 0), temp2_reg);
  87   __ cmp_and_brx_short(temp_reg, temp2_reg, Assembler::equal, Assembler::pt, L_ok);
  88   intptr_t super_check_offset = klass->super_check_offset();
  89   __ ld_ptr(Address(temp_reg, super_check_offset), temp_reg);
  90   __ set(ExternalAddress((Metadata**)klass_addr), temp2_reg);
  91   __ ld_ptr(Address(temp2_reg, 0), temp2_reg);
  92   __ cmp_and_brx_short(temp_reg, temp2_reg, Assembler::equal, Assembler::pt, L_ok);
  93   __ BIND(L_bad);
  94   if (did_save)  __ restore();
  95   __ STOP(error_message);
  96   __ BIND(L_ok);
  97   if (did_save)  __ restore();
  98   BLOCK_COMMENT("} verify_klass");
  99 }
 100 
 101 void MethodHandles::verify_ref_kind(MacroAssembler* _masm, int ref_kind, Register member_reg, Register temp) {
 102   Label L;
 103   BLOCK_COMMENT("verify_ref_kind {");
 104   __ lduw(Address(member_reg, NONZERO(java_lang_invoke_MemberName::flags_offset_in_bytes())), temp);
 105   __ srl( temp, java_lang_invoke_MemberName::MN_REFERENCE_KIND_SHIFT, temp);
 106   __ and3(temp, java_lang_invoke_MemberName::MN_REFERENCE_KIND_MASK,  temp);
 107   __ cmp_and_br_short(temp, ref_kind, Assembler::equal, Assembler::pt, L);
 108   { char* buf = NEW_C_HEAP_ARRAY(char, 100, mtInternal);
 109     jio_snprintf(buf, 100, "verify_ref_kind expected %x", ref_kind);
 110     if (ref_kind == JVM_REF_invokeVirtual ||
 111         ref_kind == JVM_REF_invokeSpecial)
 112       // could do this for all ref_kinds, but would explode assembly code size
 113       trace_method_handle(_masm, buf);
 114     __ STOP(buf);
 115   }
 116   BLOCK_COMMENT("} verify_ref_kind");
 117   __ bind(L);
 118 }
 119 
 120 #endif // ASSERT
 121 
 122 void MethodHandles::jump_from_method_handle(MacroAssembler* _masm, Register method, Register target, Register temp,
 123                                             bool for_compiler_entry) {
 124   Label L_no_such_method;
 125   assert(method == G5_method, "interpreter calling convention");
 126   assert_different_registers(method, target, temp);
 127 
 128   if (!for_compiler_entry && JvmtiExport::can_post_interpreter_events()) {
 129     Label run_compiled_code;
 130     // JVMTI events, such as single-stepping, are implemented partly by avoiding running
 131     // compiled code in threads for which the event is enabled.  Check here for
 132     // interp_only_mode if these events CAN be enabled.
 133     __ verify_thread();
 134     const Address interp_only(G2_thread, JavaThread::interp_only_mode_offset());
 135     __ ld(interp_only, temp);
 136     __ cmp_and_br_short(temp, 0, Assembler::zero, Assembler::pt, run_compiled_code);
 137     // Null method test is replicated below in compiled case,
 138     // it might be able to address across the verify_thread()
 139     __ br_null_short(G5_method, Assembler::pn, L_no_such_method);
 140     __ ld_ptr(G5_method, in_bytes(Method::interpreter_entry_offset()), target);
 141     __ jmp(target, 0);
 142     __ delayed()->nop();
 143     __ BIND(run_compiled_code);
 144     // Note: we could fill some delay slots here, but
 145     // it doesn't matter, since this is interpreter code.
 146   }
 147 
 148   // Compiled case, either static or fall-through from runtime conditional
 149   __ br_null_short(G5_method, Assembler::pn, L_no_such_method);
 150 
 151   const ByteSize entry_offset = for_compiler_entry ? Method::from_compiled_offset() :
 152                                                      Method::from_interpreted_offset();
 153   __ ld_ptr(G5_method, in_bytes(entry_offset), target);
 154   __ jmp(target, 0);
 155   __ delayed()->nop();
 156 
 157   __ bind(L_no_such_method);
 158   AddressLiteral ame(StubRoutines::throw_AbstractMethodError_entry());
 159   __ jump_to(ame, temp);
 160   __ delayed()->nop();
 161 }
 162 
 163 void MethodHandles::jump_to_lambda_form(MacroAssembler* _masm,
 164                                         Register recv, Register method_temp,
 165                                         Register temp2, Register temp3,
 166                                         bool for_compiler_entry) {
 167   BLOCK_COMMENT("jump_to_lambda_form {");
 168   // This is the initial entry point of a lazy method handle.
 169   // After type checking, it picks up the invoker from the LambdaForm.
 170   assert_different_registers(recv, method_temp, temp2);  // temp3 is only passed on
 171   assert(method_temp == G5_method, "required register for loading method");
 172 
 173   //NOT_PRODUCT({ FlagSetting fs(TraceMethodHandles, true); trace_method_handle(_masm, "LZMH"); });
 174 
 175   // Load the invoker, as MH -> MH.form -> LF.vmentry
 176   __ verify_oop(recv);
 177   __ load_heap_oop(Address(recv,        NONZERO(java_lang_invoke_MethodHandle::form_offset_in_bytes())),   method_temp);
 178   __ verify_oop(method_temp);
 179   __ load_heap_oop(Address(method_temp, NONZERO(java_lang_invoke_LambdaForm::vmentry_offset_in_bytes())),  method_temp);
 180   __ verify_oop(method_temp);
 181   // the following assumes that a Method* is normally compressed in the vmtarget field:
 182   __ ld_ptr(       Address(method_temp, NONZERO(java_lang_invoke_MemberName::vmtarget_offset_in_bytes())), method_temp);
 183 
 184   if (VerifyMethodHandles && !for_compiler_entry) {
 185     // make sure recv is already on stack
 186     __ ld_ptr(method_temp, in_bytes(Method::const_offset()), temp2);
 187     __ load_sized_value(Address(temp2, ConstMethod::size_of_parameters_offset()),
 188                         temp2,
 189                         sizeof(u2), /*is_signed*/ false);
 190     // assert(sizeof(u2) == sizeof(Method::_size_of_parameters), "");
 191     Label L;
 192     __ ld_ptr(__ argument_address(temp2, temp2, -1), temp2);
 193     __ cmp_and_br_short(temp2, recv, Assembler::equal, Assembler::pt, L);
 194     __ STOP("receiver not on stack");
 195     __ BIND(L);
 196   }
 197 
 198   jump_from_method_handle(_masm, method_temp, temp2, temp3, for_compiler_entry);
 199   BLOCK_COMMENT("} jump_to_lambda_form");
 200 }
 201 
 202 
 203 // Code generation
 204 address MethodHandles::generate_method_handle_interpreter_entry(MacroAssembler* _masm,
 205                                                                 vmIntrinsics::ID iid) {
 206   const bool not_for_compiler_entry = false;  // this is the interpreter entry
 207   assert(is_signature_polymorphic(iid), "expected invoke iid");
 208   if (iid == vmIntrinsics::_invokeGeneric ||
 209       iid == vmIntrinsics::_compiledLambdaForm) {
 210     // Perhaps surprisingly, the symbolic references visible to Java are not directly used.
 211     // They are linked to Java-generated adapters via MethodHandleNatives.linkMethod.
 212     // They all allow an appendix argument.
 213     __ should_not_reach_here();           // empty stubs make SG sick
 214     return NULL;
 215   }
 216 
 217   // I5_savedSP/O5_savedSP: sender SP (must preserve; see prepare_to_jump_from_interpreted)
 218   // G5_method:  Method*
 219   // G4 (Gargs): incoming argument list (must preserve)
 220   // O0: used as temp to hold mh or receiver
 221   // O1, O4: garbage temps, blown away
 222   Register O1_scratch    = O1;
 223   Register O4_param_size = O4;   // size of parameters
 224 
 225   // here's where control starts out:
 226   __ align(CodeEntryAlignment);
 227   address entry_point = __ pc();
 228 
 229   if (VerifyMethodHandles) {
 230     Label L;
 231     BLOCK_COMMENT("verify_intrinsic_id {");
 232     __ ldub(Address(G5_method, Method::intrinsic_id_offset_in_bytes()), O1_scratch);
 233     __ cmp_and_br_short(O1_scratch, (int) iid, Assembler::equal, Assembler::pt, L);
 234     if (iid == vmIntrinsics::_linkToVirtual ||
 235         iid == vmIntrinsics::_linkToSpecial) {
 236       // could do this for all kinds, but would explode assembly code size
 237       trace_method_handle(_masm, "bad Method*::intrinsic_id");
 238     }
 239     __ STOP("bad Method*::intrinsic_id");
 240     __ bind(L);
 241     BLOCK_COMMENT("} verify_intrinsic_id");
 242   }
 243 
 244   // First task:  Find out how big the argument list is.
 245   Address O4_first_arg_addr;
 246   int ref_kind = signature_polymorphic_intrinsic_ref_kind(iid);
 247   assert(ref_kind != 0 || iid == vmIntrinsics::_invokeBasic, "must be _invokeBasic or a linkTo intrinsic");
 248   if (ref_kind == 0 || MethodHandles::ref_kind_has_receiver(ref_kind)) {
 249     __ ld_ptr(G5_method, in_bytes(Method::const_offset()), O4_param_size);
 250     __ load_sized_value(Address(O4_param_size, ConstMethod::size_of_parameters_offset()),
 251                         O4_param_size,
 252                         sizeof(u2), /*is_signed*/ false);
 253     // assert(sizeof(u2) == sizeof(Method::_size_of_parameters), "");
 254     O4_first_arg_addr = __ argument_address(O4_param_size, O4_param_size, -1);
 255   } else {
 256     DEBUG_ONLY(O4_param_size = noreg);
 257   }
 258 
 259   Register O0_mh = noreg;
 260   if (!is_signature_polymorphic_static(iid)) {
 261     __ ld_ptr(O4_first_arg_addr, O0_mh = O0);
 262     DEBUG_ONLY(O4_param_size = noreg);
 263   }
 264 
 265   // O4_first_arg_addr is live!
 266 
 267   if (TraceMethodHandles) {
 268     if (O0_mh != noreg)
 269       __ mov(O0_mh, G3_method_handle);  // make stub happy
 270     trace_method_handle_interpreter_entry(_masm, iid);
 271   }
 272 
 273   if (iid == vmIntrinsics::_invokeBasic) {
 274     generate_method_handle_dispatch(_masm, iid, O0_mh, noreg, not_for_compiler_entry);
 275 
 276   } else {
 277     // Adjust argument list by popping the trailing MemberName argument.
 278     Register O0_recv = noreg;
 279     if (MethodHandles::ref_kind_has_receiver(ref_kind)) {
 280       // Load the receiver (not the MH; the actual MemberName's receiver) up from the interpreter stack.
 281       __ ld_ptr(O4_first_arg_addr, O0_recv = O0);
 282       DEBUG_ONLY(O4_param_size = noreg);
 283     }
 284     Register G5_member = G5_method;  // MemberName ptr; incoming method ptr is dead now
 285     __ ld_ptr(__ argument_address(constant(0)), G5_member);
 286     __ add(Gargs, Interpreter::stackElementSize, Gargs);
 287     generate_method_handle_dispatch(_masm, iid, O0_recv, G5_member, not_for_compiler_entry);
 288   }
 289 
 290   return entry_point;
 291 }
 292 
 293 void MethodHandles::generate_method_handle_dispatch(MacroAssembler* _masm,
 294                                                     vmIntrinsics::ID iid,
 295                                                     Register receiver_reg,
 296                                                     Register member_reg,
 297                                                     bool for_compiler_entry) {
 298   assert(is_signature_polymorphic(iid), "expected invoke iid");
 299   Register temp1 = (for_compiler_entry ? G1_scratch : O1);
 300   Register temp2 = (for_compiler_entry ? G3_scratch : O2);
 301   Register temp3 = (for_compiler_entry ? G4_scratch : O3);
 302   Register temp4 = (for_compiler_entry ? noreg      : O4);
 303   if (for_compiler_entry) {
 304     assert(receiver_reg == (iid == vmIntrinsics::_linkToStatic ? noreg : O0), "only valid assignment");
 305     assert_different_registers(temp1, O0, O1, O2, O3, O4, O5);
 306     assert_different_registers(temp2, O0, O1, O2, O3, O4, O5);
 307     assert_different_registers(temp3, O0, O1, O2, O3, O4, O5);
 308     assert_different_registers(temp4, O0, O1, O2, O3, O4, O5);
 309   } else {
 310     assert_different_registers(temp1, temp2, temp3, temp4, O5_savedSP);  // don't trash lastSP
 311   }
 312   if (receiver_reg != noreg)  assert_different_registers(temp1, temp2, temp3, temp4, receiver_reg);
 313   if (member_reg   != noreg)  assert_different_registers(temp1, temp2, temp3, temp4, member_reg);
 314 
 315   if (iid == vmIntrinsics::_invokeBasic) {
 316     // indirect through MH.form.vmentry.vmtarget
 317     jump_to_lambda_form(_masm, receiver_reg, G5_method, temp1, temp2, for_compiler_entry);
 318 
 319   } else {
 320     // The method is a member invoker used by direct method handles.
 321     if (VerifyMethodHandles) {
 322       // make sure the trailing argument really is a MemberName (caller responsibility)
 323       verify_klass(_masm, member_reg, SystemDictionary::WK_KLASS_ENUM_NAME(MemberName_klass),
 324                    temp1, temp2,
 325                    "MemberName required for invokeVirtual etc.");
 326     }
 327 
 328     Address member_clazz(    member_reg, NONZERO(java_lang_invoke_MemberName::clazz_offset_in_bytes()));
 329     Address member_vmindex(  member_reg, NONZERO(java_lang_invoke_MemberName::vmindex_offset_in_bytes()));
 330     Address member_vmtarget( member_reg, NONZERO(java_lang_invoke_MemberName::vmtarget_offset_in_bytes()));
 331 
 332     Register temp1_recv_klass = temp1;
 333     if (iid != vmIntrinsics::_linkToStatic) {
 334       __ verify_oop(receiver_reg);
 335       if (iid == vmIntrinsics::_linkToSpecial) {
 336         // Don't actually load the klass; just null-check the receiver.
 337         __ null_check(receiver_reg);
 338       } else {
 339         // load receiver klass itself
 340         __ null_check(receiver_reg, oopDesc::klass_offset_in_bytes());
 341         __ load_klass(receiver_reg, temp1_recv_klass);
 342         __ verify_klass_ptr(temp1_recv_klass);
 343       }
 344       BLOCK_COMMENT("check_receiver {");
 345       // The receiver for the MemberName must be in receiver_reg.
 346       // Check the receiver against the MemberName.clazz
 347       if (VerifyMethodHandles && iid == vmIntrinsics::_linkToSpecial) {
 348         // Did not load it above...
 349         __ load_klass(receiver_reg, temp1_recv_klass);
 350         __ verify_klass_ptr(temp1_recv_klass);
 351       }
 352       if (VerifyMethodHandles && iid != vmIntrinsics::_linkToInterface) {
 353         Label L_ok;
 354         Register temp2_defc = temp2;
 355         __ load_heap_oop(member_clazz, temp2_defc);
 356         load_klass_from_Class(_masm, temp2_defc, temp3, temp4);
 357         __ verify_klass_ptr(temp2_defc);
 358         __ check_klass_subtype(temp1_recv_klass, temp2_defc, temp3, temp4, L_ok);
 359         // If we get here, the type check failed!
 360         __ STOP("receiver class disagrees with MemberName.clazz");
 361         __ bind(L_ok);
 362       }
 363       BLOCK_COMMENT("} check_receiver");
 364     }
 365     if (iid == vmIntrinsics::_linkToSpecial ||
 366         iid == vmIntrinsics::_linkToStatic) {
 367       DEBUG_ONLY(temp1_recv_klass = noreg);  // these guys didn't load the recv_klass
 368     }
 369 
 370     // Live registers at this point:
 371     //  member_reg - MemberName that was the trailing argument
 372     //  temp1_recv_klass - klass of stacked receiver, if needed
 373     //  O5_savedSP - interpreter linkage (if interpreted)
 374     //  O0..O5 - compiler arguments (if compiled)
 375 
 376     Label L_incompatible_class_change_error;
 377     switch (iid) {
 378     case vmIntrinsics::_linkToSpecial:
 379       if (VerifyMethodHandles) {
 380         verify_ref_kind(_masm, JVM_REF_invokeSpecial, member_reg, temp2);
 381       }
 382       __ ld_ptr(member_vmtarget, G5_method);
 383       break;
 384 
 385     case vmIntrinsics::_linkToStatic:
 386       if (VerifyMethodHandles) {
 387         verify_ref_kind(_masm, JVM_REF_invokeStatic, member_reg, temp2);
 388       }
 389       __ ld_ptr(member_vmtarget, G5_method);
 390       break;
 391 
 392     case vmIntrinsics::_linkToVirtual:
 393     {
 394       // same as TemplateTable::invokevirtual,
 395       // minus the CP setup and profiling:
 396 
 397       if (VerifyMethodHandles) {
 398         verify_ref_kind(_masm, JVM_REF_invokeVirtual, member_reg, temp2);
 399       }
 400 
 401       // pick out the vtable index from the MemberName, and then we can discard it:
 402       Register temp2_index = temp2;
 403       __ ld_ptr(member_vmindex, temp2_index);
 404 
 405       if (VerifyMethodHandles) {
 406         Label L_index_ok;
 407         __ cmp_and_br_short(temp2_index, (int) 0, Assembler::greaterEqual, Assembler::pn, L_index_ok);
 408         __ STOP("no virtual index");
 409         __ BIND(L_index_ok);
 410       }
 411 
 412       // Note:  The verifier invariants allow us to ignore MemberName.clazz and vmtarget
 413       // at this point.  And VerifyMethodHandles has already checked clazz, if needed.
 414 
 415       // get target Method* & entry point
 416       __ lookup_virtual_method(temp1_recv_klass, temp2_index, G5_method);
 417       break;
 418     }
 419 
 420     case vmIntrinsics::_linkToInterface:
 421     {
 422       // same as TemplateTable::invokeinterface
 423       // (minus the CP setup and profiling, with different argument motion)
 424       if (VerifyMethodHandles) {
 425         verify_ref_kind(_masm, JVM_REF_invokeInterface, member_reg, temp2);
 426       }
 427 
 428       Register temp2_intf = temp2;
 429       __ load_heap_oop(member_clazz, temp2_intf);
 430       load_klass_from_Class(_masm, temp2_intf, temp3, temp4);
 431       __ verify_klass_ptr(temp2_intf);
 432 
 433       Register G5_index = G5_method;
 434       __ ld_ptr(member_vmindex, G5_index);
 435       if (VerifyMethodHandles) {
 436         Label L;
 437         __ cmp_and_br_short(G5_index, 0, Assembler::greaterEqual, Assembler::pt, L);
 438         __ STOP("invalid vtable index for MH.invokeInterface");
 439         __ bind(L);
 440       }
 441 
 442       // given intf, index, and recv klass, dispatch to the implementation method
 443       __ lookup_interface_method(temp1_recv_klass, temp2_intf,
 444                                  // note: next two args must be the same:
 445                                  G5_index, G5_method,
 446                                  temp3, temp4,
 447                                  L_incompatible_class_change_error);
 448       break;
 449     }
 450 
 451     default:
 452       fatal(err_msg_res("unexpected intrinsic %d: %s", iid, vmIntrinsics::name_at(iid)));
 453       break;
 454     }
 455 
 456     // Live at this point:
 457     //   G5_method
 458     //   O5_savedSP (if interpreted)
 459 
 460     // After figuring out which concrete method to call, jump into it.
 461     // Note that this works in the interpreter with no data motion.
 462     // But the compiled version will require that rcx_recv be shifted out.
 463     __ verify_method_ptr(G5_method);
 464     jump_from_method_handle(_masm, G5_method, temp1, temp2, for_compiler_entry);
 465 
 466     if (iid == vmIntrinsics::_linkToInterface) {
 467       __ BIND(L_incompatible_class_change_error);
 468       AddressLiteral icce(StubRoutines::throw_IncompatibleClassChangeError_entry());
 469       __ jump_to(icce, temp1);
 470       __ delayed()->nop();
 471     }
 472   }
 473 }
 474 
 475 #ifndef PRODUCT
 476 void trace_method_handle_stub(const char* adaptername,
 477                               oopDesc* mh,
 478                               intptr_t* saved_sp,
 479                               intptr_t* args,
 480                               intptr_t* tracing_fp) {
 481   bool has_mh = (strstr(adaptername, "/static") == NULL &&
 482                  strstr(adaptername, "linkTo") == NULL);    // static linkers don't have MH
 483   const char* mh_reg_name = has_mh ? "G3_mh" : "G3";
 484   tty->print_cr("MH %s %s="INTPTR_FORMAT " saved_sp=" INTPTR_FORMAT " args=" INTPTR_FORMAT,
 485                 adaptername, mh_reg_name,
 486                 (intptr_t) mh, saved_sp, args);
 487 
 488   if (Verbose) {
 489     // dumping last frame with frame::describe
 490 
 491     JavaThread* p = JavaThread::active();
 492 
 493     ResourceMark rm;
 494     PRESERVE_EXCEPTION_MARK; // may not be needed by safer and unexpensive here
 495     FrameValues values;
 496 
 497     // Note: We want to allow trace_method_handle from any call site.
 498     // While trace_method_handle creates a frame, it may be entered
 499     // without a valid return PC in O7 (e.g. not just after a call).
 500     // Walking that frame could lead to failures due to that invalid PC.
 501     // => carefully detect that frame when doing the stack walking
 502 
 503     // walk up to the right frame using the "tracing_fp" argument
 504     intptr_t* cur_sp = StubRoutines::Sparc::flush_callers_register_windows_func()();
 505     frame cur_frame(cur_sp, frame::unpatchable, NULL);
 506 
 507     while (cur_frame.fp() != (intptr_t *)(STACK_BIAS+(uintptr_t)tracing_fp)) {
 508       cur_frame = os::get_sender_for_C_frame(&cur_frame);
 509     }
 510 
 511     // safely create a frame and call frame::describe
 512     intptr_t *dump_sp = cur_frame.sender_sp();
 513     intptr_t *dump_fp = cur_frame.link();
 514 
 515     bool walkable = has_mh; // whether the traced frame shoud be walkable
 516 
 517     // the sender for cur_frame is the caller of trace_method_handle
 518     if (walkable) {
 519       // The previous definition of walkable may have to be refined
 520       // if new call sites cause the next frame constructor to start
 521       // failing. Alternatively, frame constructors could be
 522       // modified to support the current or future non walkable
 523       // frames (but this is more intrusive and is not considered as
 524       // part of this RFE, which will instead use a simpler output).
 525       frame dump_frame = frame(dump_sp,
 526                                cur_frame.sp(), // younger_sp
 527                                false); // no adaptation
 528       dump_frame.describe(values, 1);
 529     } else {
 530       // Robust dump for frames which cannot be constructed from sp/younger_sp
 531       // Add descriptions without building a Java frame to avoid issues
 532       values.describe(-1, dump_fp, "fp for #1 <not parsed, cannot trust pc>");
 533       values.describe(-1, dump_sp, "sp");
 534     }
 535 
 536     bool has_args = has_mh; // whether Gargs is meaningful
 537 
 538     // mark args, if seems valid (may not be valid for some adapters)
 539     if (has_args) {
 540       if ((args >= dump_sp) && (args < dump_fp)) {
 541         values.describe(-1, args, "*G4_args");
 542       }
 543     }
 544 
 545     // mark saved_sp, if seems valid (may not be valid for some adapters)
 546     intptr_t *unbiased_sp = (intptr_t *)(STACK_BIAS+(uintptr_t)saved_sp);
 547     const int ARG_LIMIT = 255, SLOP = 45, UNREASONABLE_STACK_MOVE = (ARG_LIMIT + SLOP);
 548     if ((unbiased_sp >= dump_sp - UNREASONABLE_STACK_MOVE) && (unbiased_sp < dump_fp)) {
 549       values.describe(-1, unbiased_sp, "*saved_sp+STACK_BIAS");
 550     }
 551 
 552     // Note: the unextended_sp may not be correct
 553     tty->print_cr("  stack layout:");
 554     values.print(p);
 555     if (has_mh && mh->is_oop()) {
 556       mh->print();
 557       if (java_lang_invoke_MethodHandle::is_instance(mh)) {
 558         if (java_lang_invoke_MethodHandle::form_offset_in_bytes() != 0)
 559           java_lang_invoke_MethodHandle::form(mh)->print();
 560       }
 561     }
 562   }
 563 }
 564 
 565 void MethodHandles::trace_method_handle(MacroAssembler* _masm, const char* adaptername) {
 566   if (!TraceMethodHandles)  return;
 567   BLOCK_COMMENT("trace_method_handle {");
 568   // save: Gargs, O5_savedSP
 569   __ save_frame(16); // need space for saving required FPU state
 570 
 571   __ set((intptr_t) adaptername, O0);
 572   __ mov(G3_method_handle, O1);
 573   __ mov(I5_savedSP, O2);
 574   __ mov(Gargs, O3);
 575   __ mov(I6, O4); // frame identifier for safe stack walking
 576 
 577   // Save scratched registers that might be needed. Robustness is more
 578   // important than optimizing the saves for this debug only code.
 579 
 580   // save FP result, valid at some call sites (adapter_opt_return_float, ...)
 581   Address d_save(FP, -sizeof(jdouble) + STACK_BIAS);
 582   __ stf(FloatRegisterImpl::D, Ftos_d, d_save);
 583   // Safely save all globals but G2 (handled by call_VM_leaf) and G7
 584   // (OS reserved).
 585   __ mov(G3_method_handle, L3);
 586   __ mov(Gargs, L4);
 587   __ mov(G5_method_type, L5);
 588   __ mov(G6, L6);
 589   __ mov(G1, L1);
 590 
 591   __ call_VM_leaf(L2 /* for G2 */, CAST_FROM_FN_PTR(address, trace_method_handle_stub));
 592 
 593   __ mov(L3, G3_method_handle);
 594   __ mov(L4, Gargs);
 595   __ mov(L5, G5_method_type);
 596   __ mov(L6, G6);
 597   __ mov(L1, G1);
 598   __ ldf(FloatRegisterImpl::D, d_save, Ftos_d);
 599 
 600   __ restore();
 601   BLOCK_COMMENT("} trace_method_handle");
 602 }
 603 #endif // PRODUCT