1/*
2 * Copyright (c) 2016, 2017, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2016, 2017, SAP SE. All rights reserved.
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 *
24 */
25
26#include "precompiled.hpp"
27#include "asm/macroAssembler.inline.hpp"
28#include "classfile/javaClasses.inline.hpp"
29#include "interpreter/interpreter.hpp"
30#include "memory/allocation.inline.hpp"
31#include "memory/resourceArea.hpp"
32#include "prims/jvm.h"
33#include "prims/methodHandles.hpp"
34
35#ifdef PRODUCT
36#define __ _masm->
37#define BLOCK_COMMENT(str) /* nothing */
38#else
39#define __ (Verbose ? (_masm->block_comment(FILE_AND_LINE),_masm):_masm)->
40#define BLOCK_COMMENT(str) __ block_comment(str)
41#endif
42
43#define BIND(label) bind(label); BLOCK_COMMENT(#label ":")
44
45// Workaround for C++ overloading nastiness on '0' for RegisterOrConstant.
46static RegisterOrConstant constant(int value) {
47  return RegisterOrConstant(value);
48}
49
50void MethodHandles::load_klass_from_Class(MacroAssembler* _masm, Register klass_reg,
51                                          Register temp_reg, Register temp2_reg) {
52  if (VerifyMethodHandles) {
53    verify_klass(_masm, klass_reg, SystemDictionary::WK_KLASS_ENUM_NAME(java_lang_Class),
54                 temp_reg, temp2_reg, "MH argument is a Class");
55  }
56  __ z_lg(klass_reg, Address(klass_reg, java_lang_Class::klass_offset_in_bytes()));
57}
58
59
60#ifdef ASSERT
61static int check_nonzero(const char* xname, int x) {
62  assert(x != 0, "%s should be nonzero", xname);
63  return x;
64}
65#define NONZERO(x) check_nonzero(#x, x)
66#else
67#define NONZERO(x) (x)
68#endif
69
70#ifdef ASSERT
71void MethodHandles::verify_klass(MacroAssembler* _masm,
72                                 Register obj_reg, SystemDictionary::WKID klass_id,
73                                 Register temp_reg, Register temp2_reg,
74                                 const char* error_message) {
75
76  InstanceKlass** klass_addr = SystemDictionary::well_known_klass_addr(klass_id);
77  Klass* klass = SystemDictionary::well_known_klass(klass_id);
78
79  assert(temp_reg != Z_R0 && // Is used as base register!
80         temp_reg != noreg && temp2_reg != noreg, "need valid registers!");
81
82  NearLabel L_ok, L_bad;
83
84  BLOCK_COMMENT("verify_klass {");
85
86  __ verify_oop(obj_reg);
87  __ compareU64_and_branch(obj_reg, (intptr_t)0L, Assembler::bcondEqual, L_bad);
88  __ load_klass(temp_reg, obj_reg);
89  // klass_addr is a klass in allstatic SystemDictionaryHandles. Can't get GCed.
90  __ load_const_optimized(temp2_reg, (address)klass_addr);
91  __ z_lg(temp2_reg, Address(temp2_reg));
92  __ compareU64_and_branch(temp_reg, temp2_reg, Assembler::bcondEqual, L_ok);
93
94  intptr_t super_check_offset = klass->super_check_offset();
95  __ z_lg(temp_reg, Address(temp_reg, super_check_offset));
96  __ compareU64_and_branch(temp_reg, temp2_reg, Assembler::bcondEqual, L_ok);
97  __ BIND(L_bad);
98  __ stop(error_message);
99  __ BIND(L_ok);
100
101  BLOCK_COMMENT("} verify_klass");
102}
103
104void MethodHandles::verify_ref_kind(MacroAssembler* _masm, int ref_kind,
105                                    Register member_reg, Register temp  ) {
106  NearLabel L;
107  BLOCK_COMMENT("verify_ref_kind {");
108
109  __ z_llgf(temp,
110            Address(member_reg,
111                    NONZERO(java_lang_invoke_MemberName::flags_offset_in_bytes())));
112  __ z_srl(temp,  java_lang_invoke_MemberName::MN_REFERENCE_KIND_SHIFT);
113  __ z_nilf(temp, java_lang_invoke_MemberName::MN_REFERENCE_KIND_MASK);
114  __ compare32_and_branch(temp, constant(ref_kind), Assembler::bcondEqual, L);
115
116  {
117    char *buf = NEW_C_HEAP_ARRAY(char, 100, mtInternal);
118
119    jio_snprintf(buf, 100, "verify_ref_kind expected %x", ref_kind);
120    if (ref_kind == JVM_REF_invokeVirtual || ref_kind == JVM_REF_invokeSpecial) {
121      // Could do this for all ref_kinds, but would explode assembly code size.
122      trace_method_handle(_masm, buf);
123    }
124    __ stop(buf);
125  }
126
127  BLOCK_COMMENT("} verify_ref_kind");
128
129  __ bind(L);
130}
131#endif // ASSERT
132
133void MethodHandles::jump_from_method_handle(MacroAssembler* _masm, Register method, Register target,
134                                            Register temp, bool for_compiler_entry) {
135  assert(method == Z_method, "interpreter calling convention");
136  __ verify_method_ptr(method);
137
138  assert(target != method, "don 't you kill the method reg!");
139
140  Label L_no_such_method;
141
142  if (!for_compiler_entry && JvmtiExport::can_post_interpreter_events()) {
143    // JVMTI events, such as single-stepping, are implemented partly
144    // by avoiding running compiled code in threads for which the
145    // event is enabled. Check here for interp_only_mode if these
146    // events CAN be enabled.
147    __ verify_thread();
148
149    Label run_compiled_code;
150
151    __ load_and_test_int(temp, Address(Z_thread, JavaThread::interp_only_mode_offset()));
152    __ z_bre(run_compiled_code);
153
154    // Null method test is replicated below in compiled case,
155    // it might be able to address across the verify_thread().
156    __ z_ltgr(temp, method);
157    __ z_bre(L_no_such_method);
158
159    __ z_lg(target, Address(method, Method::interpreter_entry_offset()));
160    __ z_br(target);
161
162    __ bind(run_compiled_code);
163  }
164
165  // Compiled case, either static or fall-through from runtime conditional.
166  __ z_ltgr(temp, method);
167  __ z_bre(L_no_such_method);
168
169  ByteSize offset = for_compiler_entry ?
170                       Method::from_compiled_offset() : Method::from_interpreted_offset();
171  Address method_from(method, offset);
172
173  __ z_lg(target, method_from);
174  __ z_br(target);
175
176  __ bind(L_no_such_method);
177  assert(StubRoutines::throw_AbstractMethodError_entry() != NULL, "not yet generated!");
178  __ load_const_optimized(target, StubRoutines::throw_AbstractMethodError_entry());
179  __ z_br(target);
180}
181
182void MethodHandles::jump_to_lambda_form(MacroAssembler* _masm,
183                                        Register recv, Register method_temp,
184                                        Register temp2, Register temp3,
185                                        bool for_compiler_entry) {
186
187  // This is the initial entry point of a lazy method handle.
188  // After type checking, it picks up the invoker from the LambdaForm.
189  assert_different_registers(recv, method_temp, temp2, temp3);
190  assert(method_temp == Z_method, "required register for loading method");
191
192  BLOCK_COMMENT("jump_to_lambda_form {");
193
194  // Load the invoker, as MH -> MH.form -> LF.vmentry
195  __ verify_oop(recv);
196  __ load_heap_oop(method_temp,
197                     Address(recv,
198                             NONZERO(java_lang_invoke_MethodHandle::form_offset_in_bytes())));
199  __ verify_oop(method_temp);
200  __ load_heap_oop(method_temp,
201                     Address(method_temp,
202                             NONZERO(java_lang_invoke_LambdaForm::vmentry_offset_in_bytes())));
203  __ verify_oop(method_temp);
204  __ load_heap_oop(method_temp,
205          Address(method_temp,
206                  NONZERO(java_lang_invoke_MemberName::method_offset_in_bytes())));
207  __ verify_oop(method_temp);
208  __ z_lg(method_temp,
209          Address(method_temp,
210                  NONZERO(java_lang_invoke_ResolvedMethodName::vmtarget_offset_in_bytes())));
211
212  if (VerifyMethodHandles && !for_compiler_entry) {
213    // Make sure recv is already on stack.
214    NearLabel L;
215    Address paramSize(temp2, ConstMethod::size_of_parameters_offset());
216
217    __ z_lg(temp2, Address(method_temp, Method::const_offset()));
218    __ load_sized_value(temp2, paramSize, sizeof(u2), /*is_signed*/ false);
219    // if (temp2 != recv) stop
220    __ z_lg(temp2, __ argument_address(temp2, temp2, 0));
221    __ compare64_and_branch(temp2, recv, Assembler::bcondEqual, L);
222    __ stop("receiver not on stack");
223    __ BIND(L);
224  }
225
226  jump_from_method_handle(_masm, method_temp, temp2, Z_R0, for_compiler_entry);
227
228  BLOCK_COMMENT("} jump_to_lambda_form");
229}
230
231// code generation
232address MethodHandles::generate_method_handle_interpreter_entry(MacroAssembler* _masm,
233                                                                vmIntrinsics::ID iid) {
234  const bool not_for_compiler_entry = false;  // This is the interpreter entry.
235  assert(is_signature_polymorphic(iid), "expected invoke iid");
236
237  if (iid == vmIntrinsics::_invokeGeneric || iid == vmIntrinsics::_compiledLambdaForm) {
238    // Perhaps surprisingly, the symbolic references visible to Java
239    // are not directly used. They are linked to Java-generated
240    // adapters via MethodHandleNatives.linkMethod. They all allow an
241    // appendix argument.
242    __ should_not_reach_here();           // Empty stubs make SG sick.
243    return NULL;
244  }
245
246  // Z_R10: sender SP (must preserve; see prepare_to_jump_from_interprted)
247  // Z_method: method
248  // Z_ARG1 (Gargs): incoming argument list (must preserve)
249  Register Z_R4_param_size = Z_R4;   // size of parameters
250  address code_start = __ pc();
251
252  // Here is where control starts out:
253  __ align(CodeEntryAlignment);
254
255  address entry_point = __ pc();
256
257  if (VerifyMethodHandles) {
258    Label L;
259    BLOCK_COMMENT("verify_intrinsic_id {");
260
261    // Supplement to 8139891: _intrinsic_id exceeded 1-byte size limit.
262    if (Method::intrinsic_id_size_in_bytes() == 1) {
263      __ z_cli(Address(Z_method, Method::intrinsic_id_offset_in_bytes()), (int)iid);
264    } else {
265      assert(Method::intrinsic_id_size_in_bytes() == 2, "size error: check Method::_intrinsic_id");
266      __ z_lh(Z_R0_scratch, Address(Z_method, Method::intrinsic_id_offset_in_bytes()));
267      __ z_chi(Z_R0_scratch, (int)iid);
268    }
269    __ z_bre(L);
270
271    if (iid == vmIntrinsics::_linkToVirtual || iid == vmIntrinsics::_linkToSpecial) {
272      // Could do this for all kinds, but would explode assembly code size.
273      trace_method_handle(_masm, "bad Method::intrinsic_id");
274    }
275
276    __ stop("bad Method::intrinsic_id");
277    __ bind(L);
278
279    BLOCK_COMMENT("} verify_intrinsic_id");
280  }
281
282  // First task: Find out how big the argument list is.
283  Address Z_R4_first_arg_addr;
284  int ref_kind = signature_polymorphic_intrinsic_ref_kind(iid);
285
286  assert(ref_kind != 0 || iid == vmIntrinsics::_invokeBasic,
287         "must be _invokeBasic or a linkTo intrinsic");
288
289  if (ref_kind == 0 || MethodHandles::ref_kind_has_receiver(ref_kind)) {
290     Address paramSize(Z_R1_scratch, ConstMethod::size_of_parameters_offset());
291
292    __ z_lg(Z_R1_scratch, Address(Z_method, Method::const_offset()));
293    __ load_sized_value(Z_R4_param_size, paramSize, sizeof(u2), /*is_signed*/ false);
294    Z_R4_first_arg_addr = __ argument_address(Z_R4_param_size, Z_R4_param_size, 0);
295  } else {
296    DEBUG_ONLY(Z_R4_param_size = noreg);
297  }
298
299  Register Z_mh = noreg;
300  if (!is_signature_polymorphic_static(iid)) {
301    Z_mh = Z_ARG4;
302    __ z_lg(Z_mh, Z_R4_first_arg_addr);
303    DEBUG_ONLY(Z_R4_param_size = noreg);
304  }
305
306  // Z_R4_first_arg_addr is live!
307
308  trace_method_handle_interpreter_entry(_masm, iid);
309
310  if (iid == vmIntrinsics::_invokeBasic) {
311    __ pc(); // just for the block comment
312    generate_method_handle_dispatch(_masm, iid, Z_mh, noreg, not_for_compiler_entry);
313  } else {
314    // Adjust argument list by popping the trailing MemberName argument.
315    Register Z_recv = noreg;
316
317    if (MethodHandles::ref_kind_has_receiver(ref_kind)) {
318      // Load the receiver (not the MH; the actual MemberName's receiver)
319      // up from the interpreter stack.
320      __ z_lg(Z_recv = Z_R5, Z_R4_first_arg_addr);
321      DEBUG_ONLY(Z_R4_param_size = noreg);
322    }
323
324    Register Z_member = Z_method;  // MemberName ptr; incoming method ptr is dead now
325
326    __ z_lg(Z_member, __ argument_address(constant(1)));
327    __ add2reg(Z_esp, Interpreter::stackElementSize);
328    generate_method_handle_dispatch(_masm, iid, Z_recv, Z_member, not_for_compiler_entry);
329  }
330
331  return entry_point;
332}
333
334void MethodHandles::generate_method_handle_dispatch(MacroAssembler* _masm,
335                                                    vmIntrinsics::ID iid,
336                                                    Register receiver_reg,
337                                                    Register member_reg,
338                                                    bool for_compiler_entry) {
339  assert(is_signature_polymorphic(iid), "expected invoke iid");
340
341  Register temp1 = for_compiler_entry ? Z_R10 : Z_R6;
342  Register temp2 = Z_R12;
343  Register temp3 = Z_R11;
344  Register temp4 = Z_R13;
345
346  if (for_compiler_entry) {
347    assert(receiver_reg == (iid == vmIntrinsics::_linkToStatic ? noreg : Z_ARG1),
348           "only valid assignment");
349  }
350  if (receiver_reg != noreg) {
351    assert_different_registers(temp1, temp2, temp3, temp4, receiver_reg);
352  }
353  if (member_reg != noreg) {
354    assert_different_registers(temp1, temp2, temp3, temp4, member_reg);
355  }
356  if (!for_compiler_entry) {  // Don't trash last SP.
357    assert_different_registers(temp1, temp2, temp3, temp4, Z_R10);
358  }
359
360  if (iid == vmIntrinsics::_invokeBasic) {
361    __ pc(); // Just for the block comment.
362    // Indirect through MH.form.vmentry.vmtarget.
363    jump_to_lambda_form(_masm, receiver_reg, Z_method, Z_R1, temp3, for_compiler_entry);
364    return;
365  }
366
367  // The method is a member invoker used by direct method handles.
368  if (VerifyMethodHandles) {
369    // Make sure the trailing argument really is a MemberName (caller responsibility).
370    verify_klass(_masm, member_reg,
371                 SystemDictionary::WK_KLASS_ENUM_NAME(MemberName_klass),
372                 temp1, temp2,
373                 "MemberName required for invokeVirtual etc.");
374  }
375
376  Address  member_clazz(   member_reg, NONZERO(java_lang_invoke_MemberName::clazz_offset_in_bytes()));
377  Address  member_vmindex( member_reg, NONZERO(java_lang_invoke_MemberName::vmindex_offset_in_bytes()));
378  Address  member_vmtarget(member_reg, NONZERO(java_lang_invoke_MemberName::method_offset_in_bytes()));
379  Address  vmtarget_method(Z_method, NONZERO(java_lang_invoke_ResolvedMethodName::vmtarget_offset_in_bytes()));
380  Register temp1_recv_klass = temp1;
381
382  if (iid != vmIntrinsics::_linkToStatic) {
383    __ verify_oop(receiver_reg);
384    if (iid == vmIntrinsics::_linkToSpecial) {
385      // Don't actually load the klass; just null-check the receiver.
386      __ null_check(receiver_reg);
387    } else {
388      // Load receiver klass itself.
389      __ null_check(receiver_reg, Z_R0, oopDesc::klass_offset_in_bytes());
390      __ load_klass(temp1_recv_klass, receiver_reg);
391      __ verify_klass_ptr(temp1_recv_klass);
392    }
393    BLOCK_COMMENT("check_receiver {");
394    // The receiver for the MemberName must be in receiver_reg.
395    // Check the receiver against the MemberName.clazz.
396    if (VerifyMethodHandles && iid == vmIntrinsics::_linkToSpecial) {
397      // Did not load it above...
398      __ load_klass(temp1_recv_klass, receiver_reg);
399      __ verify_klass_ptr(temp1_recv_klass);
400    }
401
402    if (VerifyMethodHandles && iid != vmIntrinsics::_linkToInterface) {
403      NearLabel L_ok;
404      Register temp2_defc = temp2;
405
406      __ load_heap_oop(temp2_defc, member_clazz);
407      load_klass_from_Class(_masm, temp2_defc, temp3, temp4);
408      __ verify_klass_ptr(temp2_defc);
409      __ check_klass_subtype(temp1_recv_klass, temp2_defc, temp3, temp4, L_ok);
410      // If we get here, the type check failed!
411      __ stop("receiver class disagrees with MemberName.clazz");
412      __ bind(L_ok);
413    }
414    BLOCK_COMMENT("} check_receiver");
415  }
416  if (iid == vmIntrinsics::_linkToSpecial || iid == vmIntrinsics::_linkToStatic) {
417    DEBUG_ONLY(temp1_recv_klass = noreg);  // These guys didn't load the recv_klass.
418  }
419
420  // Live registers at this point:
421  //   member_reg       - MemberName that was the trailing argument.
422  //   temp1_recv_klass - Klass of stacked receiver, if needed.
423  //   Z_R10            - Interpreter linkage if interpreted.
424
425  bool method_is_live = false;
426
427  switch (iid) {
428    case vmIntrinsics::_linkToSpecial:
429      if (VerifyMethodHandles) {
430        verify_ref_kind(_masm, JVM_REF_invokeSpecial, member_reg, temp3);
431      }
432      __ load_heap_oop(Z_method, member_vmtarget);
433      __ z_lg(Z_method, vmtarget_method);
434      method_is_live = true;
435      break;
436
437    case vmIntrinsics::_linkToStatic:
438      if (VerifyMethodHandles) {
439        verify_ref_kind(_masm, JVM_REF_invokeStatic, member_reg, temp3);
440      }
441      __ load_heap_oop(Z_method, member_vmtarget);
442      __ z_lg(Z_method, vmtarget_method);
443      method_is_live = true;
444      break;
445
446    case vmIntrinsics::_linkToVirtual: {
447      // Same as TemplateTable::invokevirtual, minus the CP setup and profiling.
448      if (VerifyMethodHandles) {
449        verify_ref_kind(_masm, JVM_REF_invokeVirtual, member_reg, temp3);
450      }
451
452      // Pick out the vtable index from the MemberName, and then we can discard it.
453      Register temp2_index = temp2;
454      __ z_lg(temp2_index, member_vmindex);
455
456      if (VerifyMethodHandles) {
457        // if (member_vmindex < 0) stop
458        NearLabel L_index_ok;
459        __ compare32_and_branch(temp2_index, constant(0), Assembler::bcondNotLow, L_index_ok);
460        __ stop("no virtual index");
461        __ BIND(L_index_ok);
462      }
463
464      // Note: The verifier invariants allow us to ignore MemberName.clazz and vmtarget
465      // at this point. And VerifyMethodHandles has already checked clazz, if needed.
466
467      // Get target method and entry point.
468      __ lookup_virtual_method(temp1_recv_klass, temp2_index, Z_method);
469      method_is_live = true;
470      break;
471    }
472
473    case vmIntrinsics::_linkToInterface: {
474      // Same as TemplateTable::invokeinterface, minus the CP setup
475      // and profiling, with different argument motion.
476      if (VerifyMethodHandles) {
477        verify_ref_kind(_masm, JVM_REF_invokeInterface, member_reg, temp3);
478      }
479
480      Register temp3_intf = temp3;
481
482      __ load_heap_oop(temp3_intf, member_clazz);
483      load_klass_from_Class(_masm, temp3_intf, temp2, temp4);
484
485      Register Z_index = Z_method;
486
487      __ z_lg(Z_index, member_vmindex);
488
489      if (VerifyMethodHandles) {
490        NearLabel L;
491        // if (member_vmindex < 0) stop
492        __ compare32_and_branch(Z_index, constant(0), Assembler::bcondNotLow, L);
493        __ stop("invalid vtable index for MH.invokeInterface");
494        __ bind(L);
495      }
496
497      // Given interface, index, and recv klass, dispatch to the implementation method.
498      Label L_no_such_interface;
499      __ lookup_interface_method(temp1_recv_klass, temp3_intf,
500                                 // Note: next two args must be the same:
501                                 Z_index, Z_method, temp2, noreg,
502                                 L_no_such_interface);
503      jump_from_method_handle(_masm, Z_method, temp2, Z_R0, for_compiler_entry);
504
505      __ bind(L_no_such_interface);
506
507      // Throw exception.
508      __ load_const_optimized(Z_R1, StubRoutines::throw_IncompatibleClassChangeError_entry());
509      __ z_br(Z_R1);
510      break;
511    }
512
513    default:
514      fatal("unexpected intrinsic %d: %s", iid, vmIntrinsics::name_at(iid));
515      break;
516  }
517
518  if (method_is_live) {
519    // Live at this point: Z_method, O5_savedSP (if interpreted).
520
521    // After figuring out which concrete method to call, jump into it.
522    // Note that this works in the interpreter with no data motion.
523    // But the compiled version will require that rcx_recv be shifted out.
524    jump_from_method_handle(_masm, Z_method, temp1, Z_R0, for_compiler_entry);
525  }
526}
527
528#ifndef PRODUCT
529void trace_method_handle_stub(const char* adaptername,
530                              oopDesc* mh,
531                              intptr_t* sender_sp,
532                              intptr_t* args,
533                              intptr_t* tracing_fp) {
534  bool has_mh = (strstr(adaptername, "/static") == NULL &&
535                 strstr(adaptername, "linkTo") == NULL);    // Static linkers don't have MH.
536  const char* mh_reg_name = has_mh ? "Z_R4_mh" : "Z_R4";
537  tty->print_cr("MH %s %s=" INTPTR_FORMAT " sender_sp=" INTPTR_FORMAT " args=" INTPTR_FORMAT,
538                adaptername, mh_reg_name,
539                p2i(mh), p2i(sender_sp), p2i(args));
540
541  if (Verbose) {
542    // Dumping last frame with frame::describe.
543
544    JavaThread* p = JavaThread::active();
545
546    ResourceMark rm;
547    PRESERVE_EXCEPTION_MARK; // May not be needed by safer and unexpensive here.
548    FrameValues values;
549
550    // Note: We want to allow trace_method_handle from any call site.
551    // While trace_method_handle creates a frame, it may be entered
552    // without a valid return PC in Z_R14 (e.g. not just after a call).
553    // Walking that frame could lead to failures due to that invalid PC.
554    // => carefully detect that frame when doing the stack walking.
555
556    // Walk up to the right frame using the "tracing_fp" argument.
557    frame cur_frame = os::current_frame(); // Current C frame.
558
559    while (cur_frame.fp() != tracing_fp) {
560      cur_frame = os::get_sender_for_C_frame(&cur_frame);
561    }
562
563    // Safely create a frame and call frame::describe.
564    intptr_t *dump_sp = cur_frame.sender_sp();
565    intptr_t *dump_fp = cur_frame.link();
566
567    bool walkable = has_mh; // Whether the traced frame shoud be walkable.
568
569    // The sender for cur_frame is the caller of trace_method_handle.
570    if (walkable) {
571      // The previous definition of walkable may have to be refined
572      // if new call sites cause the next frame constructor to start
573      // failing. Alternatively, frame constructors could be
574      // modified to support the current or future non walkable
575      // frames (but this is more intrusive and is not considered as
576      // part of this RFE, which will instead use a simpler output).
577      frame dump_frame = frame(dump_sp);
578      dump_frame.describe(values, 1);
579    } else {
580      // Robust dump for frames which cannot be constructed from sp/younger_sp
581      // Add descriptions without building a Java frame to avoid issues.
582      values.describe(-1, dump_fp, "fp for #1 <not parsed, cannot trust pc>");
583      values.describe(-1, dump_sp, "sp");
584    }
585
586    bool has_args = has_mh; // Whether Z_esp is meaningful.
587
588    // Mark args, if seems valid (may not be valid for some adapters).
589    if (has_args) {
590      if ((args >= dump_sp) && (args < dump_fp)) {
591        values.describe(-1, args, "*Z_esp");
592      }
593    }
594
595    // Note: the unextended_sp may not be correct.
596    tty->print_cr("  stack layout:");
597    values.print(p);
598    if (has_mh && oopDesc::is_oop(mh)) {
599      mh->print();
600      if (java_lang_invoke_MethodHandle::is_instance(mh)) {
601        if (java_lang_invoke_MethodHandle::form_offset_in_bytes() != 0) {
602          java_lang_invoke_MethodHandle::form(mh)->print();
603        }
604      }
605    }
606  }
607}
608
609void MethodHandles::trace_method_handle(MacroAssembler* _masm, const char* adaptername) {
610  if (!TraceMethodHandles) { return; }
611
612  // If arg registers are contiguous, we can use STMG/LMG.
613  assert((Z_ARG5->encoding() - Z_ARG1->encoding() + 1) == RegisterImpl::number_of_arg_registers, "Oops");
614
615  BLOCK_COMMENT("trace_method_handle {");
616
617  // Save argument registers (they are used in raise exception stub).
618  // Argument registers have contiguous register numbers -> we can use stmg/lmg.
619  __ z_stmg(Z_ARG1, Z_ARG5, 16, Z_SP);
620
621  // Setup arguments.
622  __ z_lgr(Z_ARG2, Z_ARG4); // mh, see generate_method_handle_interpreter_entry()
623  __ z_lgr(Z_ARG3, Z_R10);  // sender_sp
624  __ z_lgr(Z_ARG4, Z_esp);
625  __ load_const_optimized(Z_ARG1, (void *)adaptername);
626  __ z_lgr(Z_ARG5, Z_SP);   // tracing_fp
627  __ save_return_pc();      // saves Z_R14
628  __ push_frame_abi160(0);
629  __ call_VM_leaf(CAST_FROM_FN_PTR(address, trace_method_handle_stub));
630  __ pop_frame();
631  __ restore_return_pc();   // restores to Z_R14
632
633  // Restore argument registers
634  __ z_lmg(Z_ARG1, Z_ARG5, 16, Z_SP);
635  __ zap_from_to(Z_SP, Z_SP, Z_R0, Z_R1, 50, -1);
636  __ zap_from_to(Z_SP, Z_SP, Z_R0, Z_R1, -1, 5);
637
638  BLOCK_COMMENT("} trace_method_handle");
639}
640#endif // !PRODUCT
641