1 /*
   2  * Copyright (c) 2008, 2014, 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 "classfile/javaClasses.inline.hpp"
  28 #include "interpreter/interpreter.hpp"
  29 #include "interpreter/interp_masm.hpp"
  30 #include "memory/allocation.inline.hpp"
  31 #include "prims/methodHandles.hpp"
  32 
  33 #define __ _masm->
  34 
  35 #ifdef PRODUCT
  36 #define BLOCK_COMMENT(str) /* nothing */
  37 #define STOP(error) stop(error)
  38 #else
  39 #define BLOCK_COMMENT(str) __ block_comment(str)
  40 #define STOP(error) block_comment(error); __ stop(error)
  41 #endif
  42 
  43 #define BIND(label) bind(label); BLOCK_COMMENT(#label ":")
  44 
  45 // Workaround for C++ overloading nastiness on '0' for RegisterOrConstant.
  46 static RegisterOrConstant constant(int value) {
  47   return RegisterOrConstant(value);
  48 }
  49 
  50 void MethodHandles::load_klass_from_Class(MacroAssembler* _masm, Register klass_reg, Register temp_reg, Register temp2_reg) {
  51   if (VerifyMethodHandles)
  52     verify_klass(_masm, klass_reg, SystemDictionary::WK_KLASS_ENUM_NAME(java_lang_Class), temp_reg, temp2_reg,
  53                  "MH argument is a Class");
  54   __ ld_ptr(Address(klass_reg, java_lang_Class::klass_offset_in_bytes()), klass_reg);
  55 }
  56 
  57 #ifdef ASSERT
  58 static int check_nonzero(const char* xname, int x) {
  59   assert(x != 0, err_msg("%s should be nonzero", xname));
  60   return x;
  61 }
  62 #define NONZERO(x) check_nonzero(#x, x)
  63 #else //ASSERT
  64 #define NONZERO(x) (x)
  65 #endif //ASSERT
  66 
  67 #ifdef ASSERT
  68 void MethodHandles::verify_klass(MacroAssembler* _masm,
  69                                  Register obj_reg, SystemDictionary::WKID klass_id,
  70                                  Register temp_reg, Register temp2_reg,
  71                                  const char* error_message) {
  72   Klass** klass_addr = SystemDictionary::well_known_klass_addr(klass_id);
  73   KlassHandle klass = SystemDictionary::well_known_klass(klass_id);
  74   bool did_save = false;
  75   if (temp_reg == noreg || temp2_reg == noreg) {
  76     temp_reg = L1;
  77     temp2_reg = L2;
  78     __ save_frame_and_mov(0, obj_reg, L0);
  79     obj_reg = L0;
  80     did_save = true;
  81   }
  82   Label L_ok, L_bad;
  83   BLOCK_COMMENT("verify_klass {");
  84   __ verify_oop(obj_reg);
  85   __ br_null_short(obj_reg, Assembler::pn, L_bad);
  86   __ load_klass(obj_reg, temp_reg);
  87   __ set(ExternalAddress((Metadata**)klass_addr), temp2_reg);
  88   __ ld_ptr(Address(temp2_reg, 0), temp2_reg);
  89   __ cmp_and_brx_short(temp_reg, temp2_reg, Assembler::equal, Assembler::pt, L_ok);
  90   intptr_t super_check_offset = klass->super_check_offset();
  91   __ ld_ptr(Address(temp_reg, super_check_offset), temp_reg);
  92   __ set(ExternalAddress((Metadata**)klass_addr), temp2_reg);
  93   __ ld_ptr(Address(temp2_reg, 0), temp2_reg);
  94   __ cmp_and_brx_short(temp_reg, temp2_reg, Assembler::equal, Assembler::pt, L_ok);
  95   __ BIND(L_bad);
  96   if (did_save)  __ restore();
  97   __ STOP(error_message);
  98   __ BIND(L_ok);
  99   if (did_save)  __ restore();
 100   BLOCK_COMMENT("} verify_klass");
 101 }
 102 
 103 void MethodHandles::verify_ref_kind(MacroAssembler* _masm, int ref_kind, Register member_reg, Register temp) {
 104   Label L;
 105   BLOCK_COMMENT("verify_ref_kind {");
 106   __ lduw(Address(member_reg, NONZERO(java_lang_invoke_MemberName::flags_offset_in_bytes())), temp);
 107   __ srl( temp, java_lang_invoke_MemberName::MN_REFERENCE_KIND_SHIFT, temp);
 108   __ and3(temp, java_lang_invoke_MemberName::MN_REFERENCE_KIND_MASK,  temp);
 109   __ cmp_and_br_short(temp, ref_kind, Assembler::equal, Assembler::pt, L);
 110   { char* buf = NEW_C_HEAP_ARRAY(char, 100, mtInternal);
 111     jio_snprintf(buf, 100, "verify_ref_kind expected %x", ref_kind);
 112     if (ref_kind == JVM_REF_invokeVirtual ||
 113         ref_kind == JVM_REF_invokeSpecial)
 114       // could do this for all ref_kinds, but would explode assembly code size
 115       trace_method_handle(_masm, buf);
 116     __ STOP(buf);
 117   }
 118   BLOCK_COMMENT("} verify_ref_kind");
 119   __ bind(L);
 120 }
 121 
 122 #endif // ASSERT
 123 
 124 void MethodHandles::jump_from_method_handle(MacroAssembler* _masm, Register method, Register target, Register temp,
 125                                             bool for_compiler_entry) {
 126   Label L_no_such_method;
 127   assert(method == G5_method, "interpreter calling convention");
 128   assert_different_registers(method, target, temp);
 129 
 130   if (!for_compiler_entry && JvmtiExport::can_post_interpreter_events()) {
 131     Label run_compiled_code;
 132     // JVMTI events, such as single-stepping, are implemented partly by avoiding running
 133     // compiled code in threads for which the event is enabled.  Check here for
 134     // interp_only_mode if these events CAN be enabled.
 135     __ verify_thread();
 136     const Address interp_only(G2_thread, JavaThread::interp_only_mode_offset());
 137     __ ld(interp_only, temp);
 138     __ cmp_and_br_short(temp, 0, Assembler::zero, Assembler::pt, run_compiled_code);
 139     // Null method test is replicated below in compiled case,
 140     // it might be able to address across the verify_thread()
 141     __ br_null_short(G5_method, Assembler::pn, L_no_such_method);
 142     __ ld_ptr(G5_method, in_bytes(Method::interpreter_entry_offset()), target);
 143     __ jmp(target, 0);
 144     __ delayed()->nop();
 145     __ BIND(run_compiled_code);
 146     // Note: we could fill some delay slots here, but
 147     // it doesn't matter, since this is interpreter code.
 148   }
 149 
 150   // Compiled case, either static or fall-through from runtime conditional
 151   __ br_null_short(G5_method, Assembler::pn, L_no_such_method);
 152 
 153   const ByteSize entry_offset = for_compiler_entry ? Method::from_compiled_offset() :
 154                                                      Method::from_interpreted_offset();
 155   __ ld_ptr(G5_method, in_bytes(entry_offset), target);
 156   __ jmp(target, 0);
 157   __ delayed()->nop();
 158 
 159   __ bind(L_no_such_method);
 160   AddressLiteral ame(StubRoutines::throw_AbstractMethodError_entry());
 161   __ jump_to(ame, temp);
 162   __ delayed()->nop();
 163 }
 164 
 165 void MethodHandles::jump_to_lambda_form(MacroAssembler* _masm,
 166                                         Register recv, Register method_temp,
 167                                         Register temp2, Register temp3,
 168                                         bool for_compiler_entry) {
 169   BLOCK_COMMENT("jump_to_lambda_form {");
 170   // This is the initial entry point of a lazy method handle.
 171   // After type checking, it picks up the invoker from the LambdaForm.
 172   assert_different_registers(recv, method_temp, temp2);  // temp3 is only passed on
 173   assert(method_temp == G5_method, "required register for loading method");
 174 
 175   //NOT_PRODUCT({ FlagSetting fs(TraceMethodHandles, true); trace_method_handle(_masm, "LZMH"); });
 176 
 177   // Load the invoker, as MH -> MH.form -> LF.vmentry
 178   __ verify_oop(recv);
 179   __ load_heap_oop(Address(recv,        NONZERO(java_lang_invoke_MethodHandle::form_offset_in_bytes())),   method_temp);
 180   __ verify_oop(method_temp);
 181   __ load_heap_oop(Address(method_temp, NONZERO(java_lang_invoke_LambdaForm::vmentry_offset_in_bytes())),  method_temp);
 182   __ verify_oop(method_temp);
 183   // the following assumes that a Method* is normally compressed in the vmtarget field:
 184   __ ld_ptr(       Address(method_temp, NONZERO(java_lang_invoke_MemberName::vmtarget_offset_in_bytes())), method_temp);
 185 
 186   if (VerifyMethodHandles && !for_compiler_entry) {
 187     // make sure recv is already on stack
 188     __ ld_ptr(method_temp, in_bytes(Method::const_offset()), temp2);
 189     __ load_sized_value(Address(temp2, ConstMethod::size_of_parameters_offset()),
 190                         temp2,
 191                         sizeof(u2), /*is_signed*/ false);
 192     // assert(sizeof(u2) == sizeof(Method::_size_of_parameters), "");
 193     Label L;
 194     __ ld_ptr(__ argument_address(temp2, temp2, -1), temp2);
 195     __ cmp_and_br_short(temp2, recv, Assembler::equal, Assembler::pt, L);
 196     __ STOP("receiver not on stack");
 197     __ BIND(L);
 198   }
 199 
 200   jump_from_method_handle(_masm, method_temp, temp2, temp3, for_compiler_entry);
 201   BLOCK_COMMENT("} jump_to_lambda_form");
 202 }
 203 
 204 
 205 // Code generation
 206 address MethodHandles::generate_method_handle_interpreter_entry(MacroAssembler* _masm,
 207                                                                 vmIntrinsics::ID iid) {
 208   const bool not_for_compiler_entry = false;  // this is the interpreter entry
 209   assert(is_signature_polymorphic(iid), "expected invoke iid");
 210   if (iid == vmIntrinsics::_invokeGeneric ||
 211       iid == vmIntrinsics::_compiledLambdaForm) {
 212     // Perhaps surprisingly, the symbolic references visible to Java are not directly used.
 213     // They are linked to Java-generated adapters via MethodHandleNatives.linkMethod.
 214     // They all allow an appendix argument.
 215     __ should_not_reach_here();           // empty stubs make SG sick
 216     return NULL;
 217   }
 218 
 219   // I5_savedSP/O5_savedSP: sender SP (must preserve; see prepare_to_jump_from_interpreted)
 220   // G5_method:  Method*
 221   // G4 (Gargs): incoming argument list (must preserve)
 222   // O0: used as temp to hold mh or receiver
 223   // O1, O4: garbage temps, blown away
 224   Register O1_scratch    = O1;
 225   Register O4_param_size = O4;   // size of parameters
 226 
 227   // here's where control starts out:
 228   __ align(CodeEntryAlignment);
 229   address entry_point = __ pc();
 230 
 231   if (VerifyMethodHandles) {
 232     Label L;
 233     BLOCK_COMMENT("verify_intrinsic_id {");
 234     __ ldub(Address(G5_method, Method::intrinsic_id_offset_in_bytes()), O1_scratch);
 235     __ cmp_and_br_short(O1_scratch, (int) iid, Assembler::equal, Assembler::pt, L);
 236     if (iid == vmIntrinsics::_linkToVirtual ||
 237         iid == vmIntrinsics::_linkToSpecial) {
 238       // could do this for all kinds, but would explode assembly code size
 239       trace_method_handle(_masm, "bad Method*::intrinsic_id");
 240     }
 241     __ STOP("bad Method*::intrinsic_id");
 242     __ bind(L);
 243     BLOCK_COMMENT("} verify_intrinsic_id");
 244   }
 245 
 246   // First task:  Find out how big the argument list is.
 247   Address O4_first_arg_addr;
 248   int ref_kind = signature_polymorphic_intrinsic_ref_kind(iid);
 249   assert(ref_kind != 0 || iid == vmIntrinsics::_invokeBasic, "must be _invokeBasic or a linkTo intrinsic");
 250   if (ref_kind == 0 || MethodHandles::ref_kind_has_receiver(ref_kind)) {
 251     __ ld_ptr(G5_method, in_bytes(Method::const_offset()), O4_param_size);
 252     __ load_sized_value(Address(O4_param_size, ConstMethod::size_of_parameters_offset()),
 253                         O4_param_size,
 254                         sizeof(u2), /*is_signed*/ false);
 255     // assert(sizeof(u2) == sizeof(Method::_size_of_parameters), "");
 256     O4_first_arg_addr = __ argument_address(O4_param_size, O4_param_size, -1);
 257   } else {
 258     DEBUG_ONLY(O4_param_size = noreg);
 259   }
 260 
 261   Register O0_mh = noreg;
 262   if (!is_signature_polymorphic_static(iid)) {
 263     __ ld_ptr(O4_first_arg_addr, O0_mh = O0);
 264     DEBUG_ONLY(O4_param_size = noreg);
 265   }
 266 
 267   // O4_first_arg_addr is live!
 268 
 269   if (TraceMethodHandles) {
 270     if (O0_mh != noreg)
 271       __ mov(O0_mh, G3_method_handle);  // make stub happy
 272     trace_method_handle_interpreter_entry(_masm, iid);
 273   }
 274 
 275   if (iid == vmIntrinsics::_invokeBasic) {
 276     generate_method_handle_dispatch(_masm, iid, O0_mh, noreg, not_for_compiler_entry);
 277 
 278   } else {
 279     // Adjust argument list by popping the trailing MemberName argument.
 280     Register O0_recv = noreg;
 281     if (MethodHandles::ref_kind_has_receiver(ref_kind)) {
 282       // Load the receiver (not the MH; the actual MemberName's receiver) up from the interpreter stack.
 283       __ ld_ptr(O4_first_arg_addr, O0_recv = O0);
 284       DEBUG_ONLY(O4_param_size = noreg);
 285     }
 286     Register G5_member = G5_method;  // MemberName ptr; incoming method ptr is dead now
 287     __ ld_ptr(__ argument_address(constant(0)), G5_member);
 288     __ add(Gargs, Interpreter::stackElementSize, Gargs);
 289     generate_method_handle_dispatch(_masm, iid, O0_recv, G5_member, not_for_compiler_entry);
 290   }
 291 
 292   return entry_point;
 293 }
 294 
 295 void MethodHandles::generate_method_handle_dispatch(MacroAssembler* _masm,
 296                                                     vmIntrinsics::ID iid,
 297                                                     Register receiver_reg,
 298                                                     Register member_reg,
 299                                                     bool for_compiler_entry) {
 300   assert(is_signature_polymorphic(iid), "expected invoke iid");
 301   Register temp1 = (for_compiler_entry ? G1_scratch : O1);
 302   Register temp2 = (for_compiler_entry ? G3_scratch : O2);
 303   Register temp3 = (for_compiler_entry ? G4_scratch : O3);
 304   Register temp4 = (for_compiler_entry ? noreg      : O4);
 305   if (for_compiler_entry) {
 306     assert(receiver_reg == (iid == vmIntrinsics::_linkToStatic ? noreg : O0), "only valid assignment");
 307     assert_different_registers(temp1, O0, O1, O2, O3, O4, O5);
 308     assert_different_registers(temp2, O0, O1, O2, O3, O4, O5);
 309     assert_different_registers(temp3, O0, O1, O2, O3, O4, O5);
 310     assert_different_registers(temp4, O0, O1, O2, O3, O4, O5);
 311   } else {
 312     assert_different_registers(temp1, temp2, temp3, temp4, O5_savedSP);  // don't trash lastSP
 313   }
 314   if (receiver_reg != noreg)  assert_different_registers(temp1, temp2, temp3, temp4, receiver_reg);
 315   if (member_reg   != noreg)  assert_different_registers(temp1, temp2, temp3, temp4, member_reg);
 316 
 317   if (iid == vmIntrinsics::_invokeBasic) {
 318     // indirect through MH.form.vmentry.vmtarget
 319     jump_to_lambda_form(_masm, receiver_reg, G5_method, temp1, temp2, for_compiler_entry);
 320 
 321   } else {
 322     // The method is a member invoker used by direct method handles.
 323     if (VerifyMethodHandles) {
 324       // make sure the trailing argument really is a MemberName (caller responsibility)
 325       verify_klass(_masm, member_reg, SystemDictionary::WK_KLASS_ENUM_NAME(MemberName_klass),
 326                    temp1, temp2,
 327                    "MemberName required for invokeVirtual etc.");
 328     }
 329 
 330     Address member_clazz(    member_reg, NONZERO(java_lang_invoke_MemberName::clazz_offset_in_bytes()));
 331     Address member_vmindex(  member_reg, NONZERO(java_lang_invoke_MemberName::vmindex_offset_in_bytes()));
 332     Address member_vmtarget( member_reg, NONZERO(java_lang_invoke_MemberName::vmtarget_offset_in_bytes()));
 333 
 334     Register temp1_recv_klass = temp1;
 335     if (iid != vmIntrinsics::_linkToStatic) {
 336       __ verify_oop(receiver_reg);
 337       if (iid == vmIntrinsics::_linkToSpecial) {
 338         // Don't actually load the klass; just null-check the receiver.
 339         __ null_check(receiver_reg);
 340       } else {
 341         // load receiver klass itself
 342         __ null_check(receiver_reg, oopDesc::klass_offset_in_bytes());
 343         __ load_klass(receiver_reg, temp1_recv_klass);
 344         __ verify_klass_ptr(temp1_recv_klass);
 345       }
 346       BLOCK_COMMENT("check_receiver {");
 347       // The receiver for the MemberName must be in receiver_reg.
 348       // Check the receiver against the MemberName.clazz
 349       if (VerifyMethodHandles && iid == vmIntrinsics::_linkToSpecial) {
 350         // Did not load it above...
 351         __ load_klass(receiver_reg, temp1_recv_klass);
 352         __ verify_klass_ptr(temp1_recv_klass);
 353       }
 354       if (VerifyMethodHandles && iid != vmIntrinsics::_linkToInterface) {
 355         Label L_ok;
 356         Register temp2_defc = temp2;
 357         __ load_heap_oop(member_clazz, temp2_defc);
 358         load_klass_from_Class(_masm, temp2_defc, temp3, temp4);
 359         __ verify_klass_ptr(temp2_defc);
 360         __ check_klass_subtype(temp1_recv_klass, temp2_defc, temp3, temp4, L_ok);
 361         // If we get here, the type check failed!
 362         __ STOP("receiver class disagrees with MemberName.clazz");
 363         __ bind(L_ok);
 364       }
 365       BLOCK_COMMENT("} check_receiver");
 366     }
 367     if (iid == vmIntrinsics::_linkToSpecial ||
 368         iid == vmIntrinsics::_linkToStatic) {
 369       DEBUG_ONLY(temp1_recv_klass = noreg);  // these guys didn't load the recv_klass
 370     }
 371 
 372     // Live registers at this point:
 373     //  member_reg - MemberName that was the trailing argument
 374     //  temp1_recv_klass - klass of stacked receiver, if needed
 375     //  O5_savedSP - interpreter linkage (if interpreted)
 376     //  O0..O5 - compiler arguments (if compiled)
 377 
 378     Label L_incompatible_class_change_error;
 379     switch (iid) {
 380     case vmIntrinsics::_linkToSpecial:
 381       if (VerifyMethodHandles) {
 382         verify_ref_kind(_masm, JVM_REF_invokeSpecial, member_reg, temp2);
 383       }
 384       __ ld_ptr(member_vmtarget, G5_method);
 385       break;
 386 
 387     case vmIntrinsics::_linkToStatic:
 388       if (VerifyMethodHandles) {
 389         verify_ref_kind(_masm, JVM_REF_invokeStatic, member_reg, temp2);
 390       }
 391       __ ld_ptr(member_vmtarget, G5_method);
 392       break;
 393 
 394     case vmIntrinsics::_linkToVirtual:
 395     {
 396       // same as TemplateTable::invokevirtual,
 397       // minus the CP setup and profiling:
 398 
 399       if (VerifyMethodHandles) {
 400         verify_ref_kind(_masm, JVM_REF_invokeVirtual, member_reg, temp2);
 401       }
 402 
 403       // pick out the vtable index from the MemberName, and then we can discard it:
 404       Register temp2_index = temp2;
 405       __ ld_ptr(member_vmindex, temp2_index);
 406 
 407       if (VerifyMethodHandles) {
 408         Label L_index_ok;
 409         __ cmp_and_br_short(temp2_index, (int) 0, Assembler::greaterEqual, Assembler::pn, L_index_ok);
 410         __ STOP("no virtual index");
 411         __ BIND(L_index_ok);
 412       }
 413 
 414       // Note:  The verifier invariants allow us to ignore MemberName.clazz and vmtarget
 415       // at this point.  And VerifyMethodHandles has already checked clazz, if needed.
 416 
 417       // get target Method* & entry point
 418       __ lookup_virtual_method(temp1_recv_klass, temp2_index, G5_method);
 419       break;
 420     }
 421 
 422     case vmIntrinsics::_linkToInterface:
 423     {
 424       // same as TemplateTable::invokeinterface
 425       // (minus the CP setup and profiling, with different argument motion)
 426       if (VerifyMethodHandles) {
 427         verify_ref_kind(_masm, JVM_REF_invokeInterface, member_reg, temp2);
 428       }
 429 
 430       Register temp2_intf = temp2;
 431       __ load_heap_oop(member_clazz, temp2_intf);
 432       load_klass_from_Class(_masm, temp2_intf, temp3, temp4);
 433       __ verify_klass_ptr(temp2_intf);
 434 
 435       Register G5_index = G5_method;
 436       __ ld_ptr(member_vmindex, G5_index);
 437       if (VerifyMethodHandles) {
 438         Label L;
 439         __ cmp_and_br_short(G5_index, 0, Assembler::greaterEqual, Assembler::pt, L);
 440         __ STOP("invalid vtable index for MH.invokeInterface");
 441         __ bind(L);
 442       }
 443 
 444       // given intf, index, and recv klass, dispatch to the implementation method
 445       __ lookup_interface_method(temp1_recv_klass, temp2_intf,
 446                                  // note: next two args must be the same:
 447                                  G5_index, G5_method,
 448                                  temp3, temp4,
 449                                  L_incompatible_class_change_error);
 450       break;
 451     }
 452 
 453     default:
 454       fatal(err_msg_res("unexpected intrinsic %d: %s", iid, vmIntrinsics::name_at(iid)));
 455       break;
 456     }
 457 
 458     // Live at this point:
 459     //   G5_method
 460     //   O5_savedSP (if interpreted)
 461 
 462     // After figuring out which concrete method to call, jump into it.
 463     // Note that this works in the interpreter with no data motion.
 464     // But the compiled version will require that rcx_recv be shifted out.
 465     __ verify_method_ptr(G5_method);
 466     jump_from_method_handle(_masm, G5_method, temp1, temp2, for_compiler_entry);
 467 
 468     if (iid == vmIntrinsics::_linkToInterface) {
 469       __ BIND(L_incompatible_class_change_error);
 470       AddressLiteral icce(StubRoutines::throw_IncompatibleClassChangeError_entry());
 471       __ jump_to(icce, temp1);
 472       __ delayed()->nop();
 473     }
 474   }
 475 }
 476 
 477 #ifndef PRODUCT
 478 void trace_method_handle_stub(const char* adaptername,
 479                               oopDesc* mh,
 480                               intptr_t* saved_sp,
 481                               intptr_t* args,
 482                               intptr_t* tracing_fp) {
 483   bool has_mh = (strstr(adaptername, "/static") == NULL &&
 484                  strstr(adaptername, "linkTo") == NULL);    // static linkers don't have MH
 485   const char* mh_reg_name = has_mh ? "G3_mh" : "G3";
 486   tty->print_cr("MH %s %s="INTPTR_FORMAT " saved_sp=" INTPTR_FORMAT " args=" INTPTR_FORMAT,
 487                 adaptername, mh_reg_name,
 488                 p2i(mh), p2i(saved_sp), p2i(args));
 489 
 490   if (Verbose) {
 491     // dumping last frame with frame::describe
 492 
 493     JavaThread* p = JavaThread::active();
 494 
 495     ResourceMark rm;
 496     PRESERVE_EXCEPTION_MARK; // may not be needed by safer and unexpensive here
 497     FrameValues values;
 498 
 499     // Note: We want to allow trace_method_handle from any call site.
 500     // While trace_method_handle creates a frame, it may be entered
 501     // without a valid return PC in O7 (e.g. not just after a call).
 502     // Walking that frame could lead to failures due to that invalid PC.
 503     // => carefully detect that frame when doing the stack walking
 504 
 505     // walk up to the right frame using the "tracing_fp" argument
 506     intptr_t* cur_sp = StubRoutines::Sparc::flush_callers_register_windows_func()();
 507     frame cur_frame(cur_sp, frame::unpatchable, NULL);
 508 
 509     while (cur_frame.fp() != (intptr_t *)(STACK_BIAS+(uintptr_t)tracing_fp)) {
 510       cur_frame = os::get_sender_for_C_frame(&cur_frame);
 511     }
 512 
 513     // safely create a frame and call frame::describe
 514     intptr_t *dump_sp = cur_frame.sender_sp();
 515     intptr_t *dump_fp = cur_frame.link();
 516 
 517     bool walkable = has_mh; // whether the traced frame shoud be walkable
 518 
 519     // the sender for cur_frame is the caller of trace_method_handle
 520     if (walkable) {
 521       // The previous definition of walkable may have to be refined
 522       // if new call sites cause the next frame constructor to start
 523       // failing. Alternatively, frame constructors could be
 524       // modified to support the current or future non walkable
 525       // frames (but this is more intrusive and is not considered as
 526       // part of this RFE, which will instead use a simpler output).
 527       frame dump_frame = frame(dump_sp,
 528                                cur_frame.sp(), // younger_sp
 529                                false); // no adaptation
 530       dump_frame.describe(values, 1);
 531     } else {
 532       // Robust dump for frames which cannot be constructed from sp/younger_sp
 533       // Add descriptions without building a Java frame to avoid issues
 534       values.describe(-1, dump_fp, "fp for #1 <not parsed, cannot trust pc>");
 535       values.describe(-1, dump_sp, "sp");
 536     }
 537 
 538     bool has_args = has_mh; // whether Gargs is meaningful
 539 
 540     // mark args, if seems valid (may not be valid for some adapters)
 541     if (has_args) {
 542       if ((args >= dump_sp) && (args < dump_fp)) {
 543         values.describe(-1, args, "*G4_args");
 544       }
 545     }
 546 
 547     // mark saved_sp, if seems valid (may not be valid for some adapters)
 548     intptr_t *unbiased_sp = (intptr_t *)(STACK_BIAS+(uintptr_t)saved_sp);
 549     const int ARG_LIMIT = 255, SLOP = 45, UNREASONABLE_STACK_MOVE = (ARG_LIMIT + SLOP);
 550     if ((unbiased_sp >= dump_sp - UNREASONABLE_STACK_MOVE) && (unbiased_sp < dump_fp)) {
 551       values.describe(-1, unbiased_sp, "*saved_sp+STACK_BIAS");
 552     }
 553 
 554     // Note: the unextended_sp may not be correct
 555     tty->print_cr("  stack layout:");
 556     values.print(p);
 557     if (has_mh && mh->is_oop()) {
 558       mh->print();
 559       if (java_lang_invoke_MethodHandle::is_instance(mh)) {
 560         if (java_lang_invoke_MethodHandle::form_offset_in_bytes() != 0)
 561           java_lang_invoke_MethodHandle::form(mh)->print();
 562       }
 563     }
 564   }
 565 }
 566 
 567 void MethodHandles::trace_method_handle(MacroAssembler* _masm, const char* adaptername) {
 568   if (!TraceMethodHandles)  return;
 569   BLOCK_COMMENT("trace_method_handle {");
 570   // save: Gargs, O5_savedSP
 571   __ save_frame(16); // need space for saving required FPU state
 572 
 573   __ set((intptr_t) adaptername, O0);
 574   __ mov(G3_method_handle, O1);
 575   __ mov(I5_savedSP, O2);
 576   __ mov(Gargs, O3);
 577   __ mov(I6, O4); // frame identifier for safe stack walking
 578 
 579   // Save scratched registers that might be needed. Robustness is more
 580   // important than optimizing the saves for this debug only code.
 581 
 582   // save FP result, valid at some call sites (adapter_opt_return_float, ...)
 583   Address d_save(FP, -sizeof(jdouble) + STACK_BIAS);
 584   __ stf(FloatRegisterImpl::D, Ftos_d, d_save);
 585   // Safely save all globals but G2 (handled by call_VM_leaf) and G7
 586   // (OS reserved).
 587   __ mov(G3_method_handle, L3);
 588   __ mov(Gargs, L4);
 589   __ mov(G5_method_type, L5);
 590   __ mov(G6, L6);
 591   __ mov(G1, L1);
 592 
 593   __ call_VM_leaf(L2 /* for G2 */, CAST_FROM_FN_PTR(address, trace_method_handle_stub));
 594 
 595   __ mov(L3, G3_method_handle);
 596   __ mov(L4, Gargs);
 597   __ mov(L5, G5_method_type);
 598   __ mov(L6, G6);
 599   __ mov(L1, G1);
 600   __ ldf(FloatRegisterImpl::D, d_save, Ftos_d);
 601 
 602   __ restore();
 603   BLOCK_COMMENT("} trace_method_handle");
 604 }
 605 #endif // PRODUCT