1 /*
  2  * Copyright (c) 1997, 2026, Oracle and/or its affiliates. All rights reserved.
  3  * Copyright (c) 2012, 2026 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 "asm/macroAssembler.inline.hpp"
 27 #include "classfile/javaClasses.inline.hpp"
 28 #include "classfile/vmClasses.hpp"
 29 #include "interpreter/interpreter.hpp"
 30 #include "jvm.h"
 31 #include "logging/log.hpp"
 32 #include "logging/logStream.hpp"
 33 #include "memory/allocation.inline.hpp"
 34 #include "memory/resourceArea.hpp"
 35 #include "prims/jvmtiExport.hpp"
 36 #include "prims/methodHandles.hpp"
 37 #include "runtime/frame.inline.hpp"
 38 #include "runtime/stubRoutines.hpp"
 39 #include "utilities/macros.hpp"
 40 #include "utilities/preserveException.hpp"
 41 
 42 #define __ _masm->
 43 
 44 #ifdef PRODUCT
 45 #define BLOCK_COMMENT(str) // nothing
 46 #else
 47 #define BLOCK_COMMENT(str) __ block_comment(str)
 48 #endif
 49 
 50 #define BIND(label) bind(label); BLOCK_COMMENT(#label ":")
 51 
 52 void MethodHandles::load_klass_from_Class(MacroAssembler* _masm, Register klass_reg,
 53                                           Register temp_reg, Register temp2_reg) {
 54   if (VerifyMethodHandles) {
 55     verify_klass(_masm, klass_reg, VM_CLASS_ID(java_lang_Class),
 56                  temp_reg, temp2_reg, "MH argument is a Class");
 57   }
 58   __ ld(klass_reg, java_lang_Class::klass_offset(), klass_reg);
 59 }
 60 
 61 #ifdef ASSERT
 62 static int check_nonzero(const char* xname, int x) {
 63   assert(x != 0, "%s should be nonzero", xname);
 64   return x;
 65 }
 66 #define NONZERO(x) check_nonzero(#x, x)
 67 #else //ASSERT
 68 #define NONZERO(x) (x)
 69 #endif //ASSERT
 70 
 71 #ifdef ASSERT
 72 void MethodHandles::verify_klass(MacroAssembler* _masm,
 73                                  Register obj_reg, vmClassID klass_id,
 74                                  Register temp_reg, Register temp2_reg,
 75                                  const char* error_message) {
 76   InstanceKlass** klass_addr = vmClasses::klass_addr_at(klass_id);
 77   Klass* klass = vmClasses::klass_at(klass_id);
 78   Label L_ok, L_bad;
 79   BLOCK_COMMENT("verify_klass {");
 80   __ verify_oop(obj_reg, FILE_AND_LINE);
 81   __ cmpdi(CR0, obj_reg, 0);
 82   __ beq(CR0, L_bad);
 83   __ load_klass(temp_reg, obj_reg);
 84   __ load_const_optimized(temp2_reg, (address) klass_addr);
 85   __ ld(temp2_reg, 0, temp2_reg);
 86   __ cmpd(CR0, temp_reg, temp2_reg);
 87   __ beq(CR0, L_ok);
 88   __ ld(temp_reg, klass->super_check_offset(), temp_reg);
 89   __ cmpd(CR0, temp_reg, temp2_reg);
 90   __ beq(CR0, L_ok);
 91   __ BIND(L_bad);
 92   __ stop(error_message);
 93   __ BIND(L_ok);
 94   BLOCK_COMMENT("} verify_klass");
 95 }
 96 
 97 void MethodHandles::verify_ref_kind(MacroAssembler* _masm, int ref_kind, Register member_reg, Register temp) {
 98   Label L;
 99   BLOCK_COMMENT("verify_ref_kind {");
100   __ load_sized_value(temp, NONZERO(java_lang_invoke_MemberName::flags_offset()), member_reg,
101                       sizeof(u4), /*is_signed*/ false);
102   // assert(sizeof(u4) == sizeof(java.lang.invoke.MemberName.flags), "");
103   __ srwi( temp, temp, java_lang_invoke_MemberName::MN_REFERENCE_KIND_SHIFT);
104   __ andi(temp, temp, java_lang_invoke_MemberName::MN_REFERENCE_KIND_MASK);
105   __ cmpwi(CR1, temp, ref_kind);
106   __ beq(CR1, L);
107   const char* msg = ref_kind_to_verify_msg(ref_kind);
108   if (ref_kind == JVM_REF_invokeVirtual ||
109       ref_kind == JVM_REF_invokeSpecial) {
110     // could do this for all ref_kinds, but would explode assembly code size
111     trace_method_handle(_masm, msg);
112   }
113   __ stop(msg);
114   BLOCK_COMMENT("} verify_ref_kind");
115   __ BIND(L);
116 }
117 
118 #endif // ASSERT
119 
120 void MethodHandles::jump_from_method_handle(MacroAssembler* _masm, Register method, Register target, Register temp,
121                                             bool for_compiler_entry) {
122   Label L_no_such_method;
123   assert(method == R19_method, "interpreter calling convention");
124   assert_different_registers(method, target, temp);
125 
126   if (!for_compiler_entry && JvmtiExport::can_post_interpreter_events()) {
127     Label run_compiled_code;
128     // JVMTI events, such as single-stepping, are implemented partly by avoiding running
129     // compiled code in threads for which the event is enabled.  Check here for
130     // interp_only_mode if these events CAN be enabled.
131     __ lwz(temp, in_bytes(JavaThread::interp_only_mode_offset()), R16_thread);
132     __ cmplwi(CR0, temp, 0);
133     __ beq(CR0, run_compiled_code);
134     // Null method test is replicated below in compiled case.
135     __ cmplwi(CR0, R19_method, 0);
136     __ beq(CR0, L_no_such_method);
137     __ ld(target, in_bytes(Method::interpreter_entry_offset()), R19_method);
138     __ mtctr(target);
139     __ bctr();
140     __ BIND(run_compiled_code);
141   }
142 
143   // Compiled case, either static or fall-through from runtime conditional
144   __ cmplwi(CR0, R19_method, 0);
145   __ beq(CR0, L_no_such_method);
146 
147   // The following jump might pass an inline type argument that was erased to Object as oop to a
148   // callee that expects inline type arguments to be passed as fields. We need to call the compiled
149   // value entry (_code->inline_entry_point() or _adapter->c2i_inline_entry()) which will take care
150   // of translating between the calling conventions.
151   const ByteSize entry_offset = for_compiler_entry ? Method::from_compiled_inline_offset() :
152                                                      Method::from_interpreted_offset();
153   __ ld(target, in_bytes(entry_offset), R19_method);
154   __ mtctr(target);
155   __ bctr();
156 
157   __ bind(L_no_such_method);
158   assert(SharedRuntime::throw_AbstractMethodError_entry() != nullptr, "not yet generated!");
159   __ load_const_optimized(target, SharedRuntime::throw_AbstractMethodError_entry());
160   __ mtctr(target);
161   __ bctr();
162 }
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);
173   assert(method_temp == R19_method, "required register for loading method");
174 
175   // Load the invoker, as MH -> MH.form -> LF.vmentry
176   __ verify_oop(recv, FILE_AND_LINE);
177 
178   const MacroAssembler::PreservationLevel preservation_level = for_compiler_entry
179     ? MacroAssembler::PRESERVATION_FRAME_LR_GP_FP_REGS
180     : MacroAssembler::PRESERVATION_FRAME_LR;
181 
182   __ load_heap_oop(method_temp, NONZERO(java_lang_invoke_MethodHandle::form_offset()), recv,
183                    temp2, temp3, preservation_level, IS_NOT_NULL);
184   __ verify_oop(method_temp, FILE_AND_LINE);
185   __ load_heap_oop(method_temp, NONZERO(java_lang_invoke_LambdaForm::vmentry_offset()), method_temp,
186                    temp2, temp3, preservation_level, IS_NOT_NULL);
187   __ verify_oop(method_temp, FILE_AND_LINE);
188   __ load_heap_oop(method_temp, NONZERO(java_lang_invoke_MemberName::method_offset()), method_temp,
189                    temp2, temp3, preservation_level, IS_NOT_NULL);
190   __ verify_oop(method_temp, FILE_AND_LINE);
191   __ ld(method_temp, NONZERO(java_lang_invoke_ResolvedMethodName::vmtarget_offset()), method_temp);
192 
193   if (VerifyMethodHandles && !for_compiler_entry) {
194     // Make sure recv is already on stack.
195     __ ld(temp2, in_bytes(Method::const_offset()), method_temp);
196     __ load_sized_value(temp2, in_bytes(ConstMethod::size_of_parameters_offset()), temp2,
197                         sizeof(u2), /*is_signed*/ false);
198     // assert(sizeof(u2) == sizeof(ConstMethod::_size_of_parameters), "");
199     Label L;
200     __ ld(temp2, __ argument_offset(temp2, temp2, 0), R15_esp);
201     __ cmpd(CR1, temp2, recv);
202     __ beq(CR1, L);
203     __ stop("receiver not on stack");
204     __ BIND(L);
205   }
206 
207   jump_from_method_handle(_masm, method_temp, temp2, temp3, for_compiler_entry);
208   BLOCK_COMMENT("} jump_to_lambda_form");
209 }
210 
211 
212 
213 // Code generation
214 address MethodHandles::generate_method_handle_interpreter_entry(MacroAssembler* _masm,
215                                                                 vmIntrinsics::ID iid) {
216   const bool not_for_compiler_entry = false;  // this is the interpreter entry
217   assert(is_signature_polymorphic(iid), "expected invoke iid");
218   if (iid == vmIntrinsics::_invokeGeneric ||
219       iid == vmIntrinsics::_compiledLambdaForm) {
220     // Perhaps surprisingly, the symbolic references visible to Java are not directly used.
221     // They are linked to Java-generated adapters via MethodHandleNatives.linkMethod.
222     // They all allow an appendix argument.
223     __ stop("Should not reach here");           // empty stubs make SG sick
224     return nullptr;
225   }
226 
227   // No need in interpreter entry for linkToNative for now.
228   // Interpreter calls compiled entry through i2c.
229   if (iid == vmIntrinsics::_linkToNative) {
230     __ stop("Should not reach here");           // empty stubs make SG sick
231     return nullptr;
232   }
233 
234   Register R15_argbase   = R15_esp; // parameter (preserved)
235   Register R30_tmp1      = R30;
236   Register R7_param_size = R7;
237 
238   // here's where control starts out:
239   __ align(CodeEntryAlignment);
240   address entry_point = __ pc();
241 
242   if (VerifyMethodHandles) {
243     assert(Method::intrinsic_id_size_in_bytes() == 2, "assuming Method::_intrinsic_id is u2");
244 
245     Label L;
246     BLOCK_COMMENT("verify_intrinsic_id {");
247     __ load_sized_value(R30_tmp1, in_bytes(Method::intrinsic_id_offset()), R19_method,
248                         sizeof(u2), /*is_signed*/ false);
249     __ cmpwi(CR1, R30_tmp1, (int) iid);
250     __ beq(CR1, L);
251     if (iid == vmIntrinsics::_linkToVirtual ||
252         iid == vmIntrinsics::_linkToSpecial) {
253       // could do this for all kinds, but would explode assembly code size
254       trace_method_handle(_masm, "bad Method*:intrinsic_id");
255     }
256     __ stop("bad Method*::intrinsic_id");
257     __ BIND(L);
258     BLOCK_COMMENT("} verify_intrinsic_id");
259   }
260 
261   // First task:  Find out how big the argument list is.
262   int ref_kind = signature_polymorphic_intrinsic_ref_kind(iid);
263   assert(ref_kind != 0 || iid == vmIntrinsics::_invokeBasic, "must be _invokeBasic or a linkTo intrinsic");
264   if (ref_kind == 0 || MethodHandles::ref_kind_has_receiver(ref_kind)) {
265     __ ld(R7_param_size, in_bytes(Method::const_offset()), R19_method);
266     __ load_sized_value(R7_param_size, in_bytes(ConstMethod::size_of_parameters_offset()), R7_param_size,
267                         sizeof(u2), /*is_signed*/ false);
268     // assert(sizeof(u2) == sizeof(ConstMethod::_size_of_parameters), "");
269   } else {
270     DEBUG_ONLY(R7_param_size = noreg);
271   }
272 
273   Register tmp_mh = noreg;
274   if (!is_signature_polymorphic_static(iid)) {
275     __ ld(tmp_mh = R30_tmp1, __ argument_offset(R7_param_size, R7_param_size, 0), R15_argbase);
276     DEBUG_ONLY(R7_param_size = noreg);
277   }
278 
279   if (log_is_enabled(Info, methodhandles)) {
280     if (tmp_mh != noreg) {
281       __ mr(R23_method_handle, tmp_mh);  // make stub happy
282     }
283     trace_method_handle_interpreter_entry(_masm, iid);
284   }
285 
286   if (iid == vmIntrinsics::_invokeBasic) {
287     generate_method_handle_dispatch(_masm, iid, tmp_mh, noreg, not_for_compiler_entry);
288 
289   } else {
290     // Adjust argument list by popping the trailing MemberName argument.
291     Register tmp_recv = noreg;
292     if (MethodHandles::ref_kind_has_receiver(ref_kind)) {
293       // Load the receiver (not the MH; the actual MemberName's receiver) up from the interpreter stack.
294       __ ld(tmp_recv = R30_tmp1, __ argument_offset(R7_param_size, R7_param_size, 0), R15_argbase);
295       DEBUG_ONLY(R7_param_size = noreg);
296     }
297     Register R19_member = R19_method;  // MemberName ptr; incoming method ptr is dead now
298     __ ld(R19_member, RegisterOrConstant((intptr_t)8), R15_argbase);
299     __ addi(R15_argbase, R15_argbase, Interpreter::stackElementSize);
300     generate_method_handle_dispatch(_masm, iid, tmp_recv, R19_member, not_for_compiler_entry);
301   }
302 
303   return entry_point;
304 }
305 
306 void MethodHandles::jump_to_native_invoker(MacroAssembler* _masm, Register nep_reg, Register temp_target) {
307   BLOCK_COMMENT("jump_to_native_invoker {");
308   assert_different_registers(nep_reg, temp_target);
309   assert(nep_reg != noreg, "required register");
310 
311   // Load the invoker, as NEP -> .invoker
312   __ verify_oop(nep_reg);
313   __ ld(temp_target, NONZERO(jdk_internal_foreign_abi_NativeEntryPoint::downcall_stub_address_offset_in_bytes()), nep_reg);
314   __ mtctr(temp_target);
315   __ bctr();
316   BLOCK_COMMENT("} jump_to_native_invoker");
317 }
318 
319 void MethodHandles::generate_method_handle_dispatch(MacroAssembler* _masm,
320                                                     vmIntrinsics::ID iid,
321                                                     Register receiver_reg,
322                                                     Register member_reg,
323                                                     bool for_compiler_entry) {
324   assert(is_signature_polymorphic(iid), "expected invoke iid");
325   Register temp1 = (for_compiler_entry ? R25_tmp5 : R31); // must be non-volatile due to runtime calls
326   Register temp2 = (for_compiler_entry ? R22_tmp2 : R8);
327   Register temp3 = (for_compiler_entry ? R23_tmp3 : R9);
328   Register temp4 = (for_compiler_entry ? R24_tmp4 : R10);
329   if (receiver_reg != noreg)  assert_different_registers(temp1, temp2, temp3, temp4, receiver_reg);
330   if (member_reg   != noreg)  assert_different_registers(temp1, temp2, temp3, temp4, member_reg);
331 
332   const MacroAssembler::PreservationLevel preservation_level = for_compiler_entry
333     ? MacroAssembler::PRESERVATION_FRAME_LR_GP_FP_REGS
334     : MacroAssembler::PRESERVATION_FRAME_LR;
335 
336   if (iid == vmIntrinsics::_invokeBasic) {
337     // indirect through MH.form.vmentry.vmtarget
338     jump_to_lambda_form(_masm, receiver_reg, R19_method, temp1, temp2, for_compiler_entry);
339   } else if (iid == vmIntrinsics::_linkToNative) {
340     assert(for_compiler_entry, "only compiler entry is supported");
341     jump_to_native_invoker(_masm, member_reg, temp1);
342   } else {
343     // The method is a member invoker used by direct method handles.
344     if (VerifyMethodHandles) {
345       // make sure the trailing argument really is a MemberName (caller responsibility)
346       verify_klass(_masm, member_reg, VM_CLASS_ID(MemberName_klass),
347                    temp1, temp2,
348                    "MemberName required for invokeVirtual etc.");
349     }
350 
351     Register temp1_recv_klass = temp1;
352     if (iid != vmIntrinsics::_linkToStatic) {
353       BLOCK_COMMENT("check_receiver {");
354       __ verify_oop(receiver_reg, FILE_AND_LINE);
355 
356       const int klass_offset = iid == vmIntrinsics::_linkToSpecial
357         ? -1                                  // enforce receiver null check
358         : oopDesc::klass_offset_in_bytes();   // regular null-checking behavior
359 
360       address NullPointerException_entry = for_compiler_entry ? SharedRuntime::throw_NullPointerException_at_call_entry()
361                                                               : Interpreter::throw_NullPointerException_entry();
362       __ null_check_throw(receiver_reg, klass_offset, temp1, NullPointerException_entry);
363 
364       if (iid != vmIntrinsics::_linkToSpecial || VerifyMethodHandles) {
365         __ load_klass(temp1_recv_klass, receiver_reg);
366         __ verify_klass_ptr(temp1_recv_klass);
367       }
368 
369       if (VerifyMethodHandles && iid != vmIntrinsics::_linkToInterface) {
370         Label L_ok;
371         Register temp2_defc = temp2;
372 
373         __ load_heap_oop(temp2_defc, NONZERO(java_lang_invoke_MemberName::clazz_offset()), member_reg,
374                          temp3, temp4, preservation_level, IS_NOT_NULL);
375         load_klass_from_Class(_masm, temp2_defc, temp3, temp4);
376         __ verify_klass_ptr(temp2_defc);
377         __ check_klass_subtype(temp1_recv_klass, temp2_defc, temp3, temp4, L_ok);
378         // If we get here, the type check failed!
379         __ stop("receiver class disagrees with MemberName.clazz");
380         __ BIND(L_ok);
381       }
382       BLOCK_COMMENT("} check_receiver");
383     }
384     if (iid == vmIntrinsics::_linkToSpecial ||
385         iid == vmIntrinsics::_linkToStatic) {
386       DEBUG_ONLY(temp1_recv_klass = noreg);  // these guys didn't load the recv_klass
387     }
388 
389     // Live registers at this point:
390     //  member_reg - MemberName that was the trailing argument
391     //  temp1_recv_klass - klass of stacked receiver, if needed
392 
393     Label L_incompatible_class_change_error;
394     switch (iid) {
395     case vmIntrinsics::_linkToSpecial:
396       if (VerifyMethodHandles) {
397         verify_ref_kind(_masm, JVM_REF_invokeSpecial, member_reg, temp2);
398       }
399       __ load_heap_oop(R19_method, NONZERO(java_lang_invoke_MemberName::method_offset()), member_reg,
400                        temp3, temp4, preservation_level, IS_NOT_NULL);
401       __ ld(R19_method, NONZERO(java_lang_invoke_ResolvedMethodName::vmtarget_offset()), R19_method);
402       break;
403 
404     case vmIntrinsics::_linkToStatic:
405       if (VerifyMethodHandles) {
406         verify_ref_kind(_masm, JVM_REF_invokeStatic, member_reg, temp2);
407       }
408       __ load_heap_oop(R19_method, NONZERO(java_lang_invoke_MemberName::method_offset()), member_reg,
409                        temp3, temp4, preservation_level, IS_NOT_NULL);
410       __ ld(R19_method, NONZERO(java_lang_invoke_ResolvedMethodName::vmtarget_offset()), R19_method);
411       break;
412 
413     case vmIntrinsics::_linkToVirtual:
414     {
415       // same as TemplateTable::invokevirtual,
416       // minus the CP setup and profiling:
417 
418       if (VerifyMethodHandles) {
419         verify_ref_kind(_masm, JVM_REF_invokeVirtual, member_reg, temp2);
420       }
421 
422       // pick out the vtable index from the MemberName, and then we can discard it:
423       Register temp2_index = temp2;
424       __ ld(temp2_index, NONZERO(java_lang_invoke_MemberName::vmindex_offset()), member_reg);
425 
426       if (VerifyMethodHandles) {
427         Label L_index_ok;
428         __ cmpdi(CR1, temp2_index, 0);
429         __ bge(CR1, L_index_ok);
430         __ stop("no virtual index");
431         __ BIND(L_index_ok);
432       }
433 
434       // Note:  The verifier invariants allow us to ignore MemberName.clazz and vmtarget
435       // at this point.  And VerifyMethodHandles has already checked clazz, if needed.
436 
437       // get target Method* & entry point
438       __ lookup_virtual_method(temp1_recv_klass, temp2_index, R19_method);
439       break;
440     }
441 
442     case vmIntrinsics::_linkToInterface:
443     {
444       // same as TemplateTable::invokeinterface
445       // (minus the CP setup and profiling, with different argument motion)
446       if (VerifyMethodHandles) {
447         verify_ref_kind(_masm, JVM_REF_invokeInterface, member_reg, temp2);
448       }
449 
450       Register temp2_intf = temp2;
451       __ load_heap_oop(temp2_intf, NONZERO(java_lang_invoke_MemberName::clazz_offset()), member_reg,
452                        temp3, temp4, preservation_level, IS_NOT_NULL);
453       load_klass_from_Class(_masm, temp2_intf, temp3, temp4);
454       __ verify_klass_ptr(temp2_intf);
455 
456       Register vtable_index = R19_method;
457       __ ld(vtable_index, NONZERO(java_lang_invoke_MemberName::vmindex_offset()), member_reg);
458       if (VerifyMethodHandles) {
459         Label L_index_ok;
460         __ cmpdi(CR1, vtable_index, 0);
461         __ bge(CR1, L_index_ok);
462         __ stop("invalid vtable index for MH.invokeInterface");
463         __ BIND(L_index_ok);
464       }
465 
466       // given intf, index, and recv klass, dispatch to the implementation method
467       __ lookup_interface_method(temp1_recv_klass, temp2_intf,
468                                  // note: next two args must be the same:
469                                  vtable_index, R19_method,
470                                  temp3, temp4,
471                                  L_incompatible_class_change_error);
472       break;
473     }
474 
475     default:
476       fatal("unexpected intrinsic %d: %s", vmIntrinsics::as_int(iid), vmIntrinsics::name_at(iid));
477       break;
478     }
479 
480     // Live at this point:
481     //   R19_method
482 
483     // After figuring out which concrete method to call, jump into it.
484     // Note that this works in the interpreter with no data motion.
485     // But the compiled version will require that rcx_recv be shifted out.
486     __ verify_method_ptr(R19_method);
487     jump_from_method_handle(_masm, R19_method, temp1, temp2, for_compiler_entry);
488 
489     if (iid == vmIntrinsics::_linkToInterface) {
490       __ BIND(L_incompatible_class_change_error);
491       __ load_const_optimized(temp1, SharedRuntime::throw_IncompatibleClassChangeError_entry());
492       __ mtctr(temp1);
493       __ bctr();
494     }
495   }
496 }
497 
498 #ifndef PRODUCT
499 void trace_method_handle_stub(const char* adaptername,
500                               oopDesc* mh,
501                               intptr_t* entry_sp,
502                               intptr_t* saved_regs) {
503 
504   bool has_mh = (strstr(adaptername, "/static") == nullptr &&
505                  strstr(adaptername, "linkTo") == nullptr);    // static linkers don't have MH
506   const char* mh_reg_name = has_mh ? "R23_method_handle" : "G23";
507   log_info(methodhandles)("MH %s %s=" INTPTR_FORMAT " sp=" INTPTR_FORMAT,
508                 adaptername, mh_reg_name, p2i(mh), p2i(entry_sp));
509 
510   LogTarget(Trace, methodhandles) lt;
511   if (lt.is_enabled()) {
512     ResourceMark rm;
513     LogStream ls(lt);
514     ls.print_cr("Registers:");
515     const int abi_offset = frame::native_abi_reg_args_size / 8;
516     for (int i = R3->encoding(); i <= R12->encoding(); i++) {
517       Register r = as_Register(i);
518       int count = i - R3->encoding();
519       // The registers are stored in reverse order on the stack (by save_volatile_gprs(R1_SP, native_abi_reg_args_size)).
520       ls.print("%3s=" PTR_FORMAT, r->name(), saved_regs[abi_offset + count]);
521       if ((count + 1) % 4 == 0) {
522         ls.cr();
523       } else {
524         ls.print(", ");
525       }
526     }
527     ls.cr();
528 
529     {
530       // dumping last frame with frame::describe
531 
532       JavaThread* p = JavaThread::active();
533 
534       // may not be needed by safer and unexpensive here
535       PreserveExceptionMark pem(Thread::current());
536       FrameValues values;
537 
538       // Note: We want to allow trace_method_handle from any call site.
539       // While trace_method_handle creates a frame, it may be entered
540       // without a PC on the stack top (e.g. not just after a call).
541       // Walking that frame could lead to failures due to that invalid PC.
542       // => carefully detect that frame when doing the stack walking
543 
544       // Current C frame
545       frame cur_frame = os::current_frame();
546 
547       // Robust search of trace_calling_frame (independent of inlining).
548       assert(cur_frame.sp() <= saved_regs, "registers not saved on stack ?");
549       frame trace_calling_frame = os::get_sender_for_C_frame(&cur_frame);
550       while (trace_calling_frame.fp() < saved_regs) {
551         trace_calling_frame = os::get_sender_for_C_frame(&trace_calling_frame);
552       }
553 
554       // Safely create a frame and call frame::describe.
555       intptr_t *dump_sp = trace_calling_frame.sender_sp();
556 
557       frame dump_frame = frame(dump_sp);
558       dump_frame.describe(values, 1);
559 
560       values.describe(-1, saved_regs, "raw top of stack");
561 
562       ls.print_cr("Stack layout:");
563       values.print_on(p, &ls);
564     }
565 
566     if (has_mh && oopDesc::is_oop(mh)) {
567       mh->print_on(&ls);
568       if (java_lang_invoke_MethodHandle::is_instance(mh)) {
569         java_lang_invoke_MethodHandle::form(mh)->print_on(&ls);
570       }
571     }
572   }
573 }
574 
575 void MethodHandles::trace_method_handle(MacroAssembler* _masm, const char* adaptername) {
576   if (!log_is_enabled(Info, methodhandles)) return;
577 
578   BLOCK_COMMENT("trace_method_handle {");
579 
580   const Register tmp = R11; // Will be preserved.
581   const int nbytes_save = MacroAssembler::num_volatile_regs * 8;
582   __ save_volatile_gprs(R1_SP, -nbytes_save); // except R0
583   __ save_LR(tmp); // save in old frame
584 
585   __ mr(R5_ARG3, R1_SP);     // saved_sp
586   __ push_frame_reg_args(nbytes_save, tmp);
587 
588   __ load_const_optimized(R3_ARG1, (address)adaptername, tmp);
589   __ mr(R4_ARG2, R23_method_handle);
590   __ mr(R6_ARG4, R1_SP);
591   __ call_VM_leaf(CAST_FROM_FN_PTR(address, trace_method_handle_stub));
592 
593   __ pop_frame();
594   __ restore_LR(tmp);
595   __ restore_volatile_gprs(R1_SP, -nbytes_save); // except R0
596 
597   BLOCK_COMMENT("} trace_method_handle");
598 }
599 #endif // PRODUCT