1 /*
2 * Copyright (c) 1997, 2025, 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 "asm/codeBuffer.hpp"
26 #include "asm/macroAssembler.inline.hpp"
27 #include "memory/resourceArea.hpp"
28 #include "oops/access.inline.hpp"
29 #include "oops/klass.hpp"
30 #include "oops/oop.inline.hpp"
31 #include "prims/vectorSupport.hpp"
32 #include "runtime/continuation.hpp"
33 #include "runtime/interfaceSupport.inline.hpp"
34 #include "runtime/timerTrace.hpp"
35 #include "runtime/sharedRuntime.hpp"
36 #include "runtime/stubRoutines.hpp"
37 #include "utilities/align.hpp"
38 #include "utilities/copy.hpp"
39 #ifdef COMPILER2
40 #include "opto/runtime.hpp"
41 #endif
42
43 UnsafeMemoryAccess* UnsafeMemoryAccess::_table = nullptr;
44 int UnsafeMemoryAccess::_table_length = 0;
45 int UnsafeMemoryAccess::_table_max_length = 0;
46 address UnsafeMemoryAccess::_common_exit_stub_pc = nullptr;
47
48 // Implementation of StubRoutines - for a description of how to
49 // declare new blobs, stubs and entries , see stubDefinitions.hpp.
50
51 // define arrays to hold stub and blob names
52
53 // use a template to generate the initializer for the blob names array
54
55 #define DEFINE_BLOB_NAME(blob_name) \
56 # blob_name,
57
58 const char* StubRoutines::_blob_names[StubGenBlobId::NUM_BLOBIDS] = {
59 STUBGEN_BLOBS_DO(DEFINE_BLOB_NAME)
60 };
61
62 #undef DEFINE_BLOB_NAME
63
64 #define DEFINE_STUB_NAME(blob_name, stub_name) \
65 # stub_name , \
66
67 // use a template to generate the initializer for the stub names array
68 const char* StubRoutines::_stub_names[StubGenStubId::NUM_STUBIDS] = {
69 STUBGEN_STUBS_DO(DEFINE_STUB_NAME)
70 };
71
72 #undef DEFINE_STUB_NAME
73
74 // Define fields used to store blobs
75
76 #define DEFINE_BLOB_FIELD(blob_name) \
77 BufferBlob* StubRoutines:: STUBGEN_BLOB_FIELD_NAME(blob_name) = nullptr;
78
79 STUBGEN_BLOBS_DO(DEFINE_BLOB_FIELD)
80
81 #undef DEFINE_BLOB_FIELD
82
83 // Define fields used to store stub entries
84
85 #define DEFINE_ENTRY_FIELD(blob_name, stub_name, field_name, getter_name) \
86 address StubRoutines:: STUB_FIELD_NAME(field_name) = nullptr;
87
88 #define DEFINE_ENTRY_FIELD_INIT(blob_name, stub_name, field_name, getter_name, init_function) \
89 address StubRoutines:: STUB_FIELD_NAME(field_name) = CAST_FROM_FN_PTR(address, init_function);
90
91 #define DEFINE_ENTRY_FIELD_ARRAY(blob_name, stub_name, field_name, getter_name, count) \
92 address StubRoutines:: STUB_FIELD_NAME(field_name)[count] = { nullptr };
93
94 STUBGEN_ENTRIES_DO(DEFINE_ENTRY_FIELD, DEFINE_ENTRY_FIELD_INIT, DEFINE_ENTRY_FIELD_ARRAY)
95
96 #undef DEFINE_ENTRY_FIELD_ARRAY
97 #undef DEFINE_ENTRY_FIELD_INIT
98 #undef DEFINE_ENTRY_FIELD
99
100 jint StubRoutines::_verify_oop_count = 0;
101
102
103 address StubRoutines::_string_indexof_array[4] = { nullptr };
104
105 const char* StubRoutines::get_blob_name(StubGenBlobId id) {
106 assert(0 <= id && id < StubGenBlobId::NUM_BLOBIDS, "invalid blob id");
107 return _blob_names[id];
108 }
109
110 const char* StubRoutines::get_stub_name(StubGenStubId id) {
111 assert(0 <= id && id < StubGenStubId::NUM_STUBIDS, "invalid stub id");
112 return _stub_names[id];
113 }
114
115 #ifdef ASSERT
116
117 // array holding start and end indices for stub ids associated with a
118 // given blob. Given a blob with id (StubGenBlobId) blob_id for any
119 // stub with id (StubGenStubId) stub_id declared within the blob:
120 // _blob_offsets[blob_id] <= stub_id < _blob_offsets[blob_id+1]
121
122 static int _blob_limits[StubGenBlobId::NUM_BLOBIDS + 1];
123
124 // macro used to compute blob limits
125 #define BLOB_COUNT(blob_name) \
126 counter += StubGenStubId_ ## blob_name :: NUM_STUBIDS_ ## blob_name; \
127 _blob_limits[++index] = counter; \
128
129 // macro that checks stubs are associated with the correct blobs
130 #define STUB_VERIFY(blob_name, stub_name) \
131 localStubId = (int) (StubGenStubId_ ## blob_name :: blob_name ## _ ## stub_name ## _id); \
132 globalStubId = (int) (StubGenStubId:: stub_name ## _id); \
133 blobId = (int) (StubGenBlobId:: blob_name ## _id); \
134 assert((globalStubId >= _blob_limits[blobId] && \
135 globalStubId < _blob_limits[blobId+1]), \
136 "stub " # stub_name " uses incorrect blob name " # blob_name); \
137 assert(globalStubId == _blob_limits[blobId] + localStubId, \
138 "stub " # stub_name " id found at wrong offset!"); \
139
140 bool verifyStubIds() {
141 // first compute the blob limits
142 int counter = 0;
143 int index = 0;
144 // populate offsets table with cumulative total of local enum counts
145 STUBGEN_BLOBS_DO(BLOB_COUNT);
146
147 // ensure 1) global stub ids lie in the range of the associated blob
148 // and 2) each blob's base + local stub id == global stub id
149 int globalStubId, blobId, localStubId;
150 STUBGEN_STUBS_DO(STUB_VERIFY);
151 return true;
152 }
153
154 #undef BLOB_COUNT
155 #undef STUB_VERIFY
156
157 // ensure we verify the blob ids when this compile unit is first entered
158 bool _verified_stub_ids = verifyStubIds();
159
160
161 // macro used by stub to blob translation
162
163 #define BLOB_CHECK_OFFSET(blob_name) \
164 if (id < _blob_limits[((int)blobId) + 1]) { return blobId; } \
165 blobId = StubGenBlobId:: blob_name ## _id; \
166
167 // translate a global stub id to an associated blob id based on the
168 // computed blob limits
169
170 StubGenBlobId StubRoutines::stub_to_blob(StubGenStubId stubId) {
171 int id = (int)stubId;
172 assert(id > ((int)StubGenStubId::NO_STUBID) && id < ((int)StubGenStubId::NUM_STUBIDS), "stub id out of range!");
173 // start with no blob to catch stub id == -1
174 StubGenBlobId blobId = StubGenBlobId::NO_BLOBID;
175 STUBGEN_BLOBS_DO(BLOB_CHECK_OFFSET);
176 // if we reach here we should have the last blob id
177 assert(blobId == StubGenBlobId::NUM_BLOBIDS - 1, "unexpected blob id");
178 return blobId;
179 }
180
181 #endif // ASSERT
182
183 // TODO: update with 8343767
184 address StubRoutines::_load_inline_type_fields_in_regs = nullptr;
185 address StubRoutines::_store_inline_type_fields_to_buf = nullptr;
186
187
188 // Initialization
189
190 extern void StubGenerator_generate(CodeBuffer* code, StubGenBlobId blob_id); // only interface to generators
191
192 void UnsafeMemoryAccess::create_table(int max_size) {
193 UnsafeMemoryAccess::_table = new UnsafeMemoryAccess[max_size];
194 UnsafeMemoryAccess::_table_max_length = max_size;
195 }
196
197 bool UnsafeMemoryAccess::contains_pc(address pc) {
198 assert(UnsafeMemoryAccess::_table != nullptr, "");
199 for (int i = 0; i < UnsafeMemoryAccess::_table_length; i++) {
200 UnsafeMemoryAccess* entry = &UnsafeMemoryAccess::_table[i];
201 if (pc >= entry->start_pc() && pc < entry->end_pc()) {
202 return true;
203 }
204 }
205 return false;
206 }
207
208 address UnsafeMemoryAccess::page_error_continue_pc(address pc) {
209 assert(UnsafeMemoryAccess::_table != nullptr, "");
210 for (int i = 0; i < UnsafeMemoryAccess::_table_length; i++) {
211 UnsafeMemoryAccess* entry = &UnsafeMemoryAccess::_table[i];
212 if (pc >= entry->start_pc() && pc < entry->end_pc()) {
213 return entry->error_exit_pc();
214 }
215 }
216 return nullptr;
217 }
218
219
220 static BufferBlob* initialize_stubs(StubGenBlobId blob_id,
221 int code_size, int max_aligned_stubs,
222 const char* timer_msg,
223 const char* buffer_name,
224 const char* assert_msg) {
225 ResourceMark rm;
226 if (code_size == 0) {
227 LogTarget(Info, stubs) lt;
228 if (lt.is_enabled()) {
229 LogStream ls(lt);
230 ls.print_cr("%s\t not generated", buffer_name);
231 return nullptr;
232 }
233 }
234 TraceTime timer(timer_msg, TRACETIME_LOG(Info, startuptime));
235 // Add extra space for large CodeEntryAlignment
236 int size = code_size + CodeEntryAlignment * max_aligned_stubs;
237 BufferBlob* stubs_code = BufferBlob::create(buffer_name, size);
238 if (stubs_code == nullptr) {
239 vm_exit_out_of_memory(code_size, OOM_MALLOC_ERROR, "CodeCache: no room for %s", buffer_name);
240 }
241 CodeBuffer buffer(stubs_code);
242 StubGenerator_generate(&buffer, blob_id);
243 // When new stubs added we need to make sure there is some space left
244 // to catch situation when we should increase size again.
245 assert(code_size == 0 || buffer.insts_remaining() > 200, "increase %s", assert_msg);
246
247 LogTarget(Info, stubs) lt;
248 if (lt.is_enabled()) {
249 LogStream ls(lt);
250 ls.print_cr("%s\t [" INTPTR_FORMAT ", " INTPTR_FORMAT "] used: %d, free: %d",
251 buffer_name, p2i(stubs_code->content_begin()), p2i(stubs_code->content_end()),
252 buffer.total_content_size(), buffer.insts_remaining());
253 }
254 return stubs_code;
255 }
256
257 #define DEFINE_BLOB_INIT_METHOD(blob_name) \
258 void StubRoutines::initialize_ ## blob_name ## _stubs() { \
259 if (STUBGEN_BLOB_FIELD_NAME(blob_name) == nullptr) { \
260 StubGenBlobId blob_id = StubGenBlobId:: STUB_ID_NAME(blob_name); \
261 int size = _ ## blob_name ## _code_size; \
262 int max_aligned_size = 10; \
263 const char* timer_msg = "StubRoutines generation " # blob_name " stubs"; \
264 const char* name = "StubRoutines (" # blob_name "stubs)"; \
265 const char* assert_msg = "_" # blob_name "_code_size"; \
266 STUBGEN_BLOB_FIELD_NAME(blob_name) = \
267 initialize_stubs(blob_id, size, max_aligned_size, timer_msg, \
268 name, assert_msg); \
269 } \
270 }
271
272
273 STUBGEN_BLOBS_DO(DEFINE_BLOB_INIT_METHOD)
274
275 #undef DEFINE_BLOB_INIT_METHOD
276
277
278 #define DEFINE_BLOB_INIT_FUNCTION(blob_name) \
279 void blob_name ## _stubs_init() { \
280 StubRoutines::initialize_ ## blob_name ## _stubs(); \
281 }
282
283 STUBGEN_BLOBS_DO(DEFINE_BLOB_INIT_FUNCTION)
284
285 #undef DEFINE_BLOB_INIT_FUNCTION
286
287 /*
288 * we generate the underlying driver method but this wrapper is needed
289 * to perform special handling depending on where the compiler init
290 * gets called from. it ought to be possible to remove this at some
291 * point and have adeterminate ordered init.
292 */
293
294 void compiler_stubs_init(bool in_compiler_thread) {
295 if (in_compiler_thread && DelayCompilerStubsGeneration) {
296 // Temporarily revert state of stubs generation because
297 // it is called after final_stubs_init() finished
298 // during compiler runtime initialization.
299 // It is fine because these stubs are only used by
300 // compiled code and compiler is not running yet.
301 StubCodeDesc::unfreeze();
302 StubRoutines::initialize_compiler_stubs();
303 StubCodeDesc::freeze();
304 } else if (!in_compiler_thread && !DelayCompilerStubsGeneration) {
305 StubRoutines::initialize_compiler_stubs();
306 }
307 }
308
309
310 //
311 // Default versions of arraycopy functions
312 //
313
314 JRT_LEAF(void, StubRoutines::jbyte_copy(jbyte* src, jbyte* dest, size_t count))
315 #ifndef PRODUCT
316 SharedRuntime::_jbyte_array_copy_ctr++; // Slow-path byte array copy
317 #endif // !PRODUCT
318 Copy::conjoint_jbytes_atomic(src, dest, count);
319 JRT_END
320
321 JRT_LEAF(void, StubRoutines::jshort_copy(jshort* src, jshort* dest, size_t count))
322 #ifndef PRODUCT
323 SharedRuntime::_jshort_array_copy_ctr++; // Slow-path short/char array copy
324 #endif // !PRODUCT
325 Copy::conjoint_jshorts_atomic(src, dest, count);
326 JRT_END
327
328 JRT_LEAF(void, StubRoutines::jint_copy(jint* src, jint* dest, size_t count))
329 #ifndef PRODUCT
330 SharedRuntime::_jint_array_copy_ctr++; // Slow-path int/float array copy
331 #endif // !PRODUCT
332 Copy::conjoint_jints_atomic(src, dest, count);
333 JRT_END
334
335 JRT_LEAF(void, StubRoutines::jlong_copy(jlong* src, jlong* dest, size_t count))
336 #ifndef PRODUCT
337 SharedRuntime::_jlong_array_copy_ctr++; // Slow-path long/double array copy
338 #endif // !PRODUCT
339 Copy::conjoint_jlongs_atomic(src, dest, count);
340 JRT_END
341
342 JRT_LEAF(void, StubRoutines::oop_copy(oop* src, oop* dest, size_t count))
343 #ifndef PRODUCT
344 SharedRuntime::_oop_array_copy_ctr++; // Slow-path oop array copy
345 #endif // !PRODUCT
346 assert(count != 0, "count should be non-zero");
347 ArrayAccess<>::oop_arraycopy_raw((HeapWord*)src, (HeapWord*)dest, count);
348 JRT_END
349
350 JRT_LEAF(void, StubRoutines::oop_copy_uninit(oop* src, oop* dest, size_t count))
351 #ifndef PRODUCT
352 SharedRuntime::_oop_array_copy_ctr++; // Slow-path oop array copy
353 #endif // !PRODUCT
354 assert(count != 0, "count should be non-zero");
355 ArrayAccess<IS_DEST_UNINITIALIZED>::oop_arraycopy_raw((HeapWord*)src, (HeapWord*)dest, count);
356 JRT_END
357
358 JRT_LEAF(void, StubRoutines::arrayof_jbyte_copy(HeapWord* src, HeapWord* dest, size_t count))
359 #ifndef PRODUCT
360 SharedRuntime::_jbyte_array_copy_ctr++; // Slow-path byte array copy
361 #endif // !PRODUCT
362 Copy::arrayof_conjoint_jbytes(src, dest, count);
363 JRT_END
364
365 JRT_LEAF(void, StubRoutines::arrayof_jshort_copy(HeapWord* src, HeapWord* dest, size_t count))
366 #ifndef PRODUCT
367 SharedRuntime::_jshort_array_copy_ctr++; // Slow-path short/char array copy
368 #endif // !PRODUCT
369 Copy::arrayof_conjoint_jshorts(src, dest, count);
370 JRT_END
371
372 JRT_LEAF(void, StubRoutines::arrayof_jint_copy(HeapWord* src, HeapWord* dest, size_t count))
373 #ifndef PRODUCT
374 SharedRuntime::_jint_array_copy_ctr++; // Slow-path int/float array copy
375 #endif // !PRODUCT
376 Copy::arrayof_conjoint_jints(src, dest, count);
377 JRT_END
378
379 JRT_LEAF(void, StubRoutines::arrayof_jlong_copy(HeapWord* src, HeapWord* dest, size_t count))
380 #ifndef PRODUCT
381 SharedRuntime::_jlong_array_copy_ctr++; // Slow-path int/float array copy
382 #endif // !PRODUCT
383 Copy::arrayof_conjoint_jlongs(src, dest, count);
384 JRT_END
385
386 JRT_LEAF(void, StubRoutines::arrayof_oop_copy(HeapWord* src, HeapWord* dest, size_t count))
387 #ifndef PRODUCT
388 SharedRuntime::_oop_array_copy_ctr++; // Slow-path oop array copy
389 #endif // !PRODUCT
390 assert(count != 0, "count should be non-zero");
391 ArrayAccess<ARRAYCOPY_ARRAYOF>::oop_arraycopy_raw(src, dest, count);
392 JRT_END
393
394 JRT_LEAF(void, StubRoutines::arrayof_oop_copy_uninit(HeapWord* src, HeapWord* dest, size_t count))
395 #ifndef PRODUCT
396 SharedRuntime::_oop_array_copy_ctr++; // Slow-path oop array copy
397 #endif // !PRODUCT
398 assert(count != 0, "count should be non-zero");
399 ArrayAccess<ARRAYCOPY_ARRAYOF | IS_DEST_UNINITIALIZED>::oop_arraycopy_raw(src, dest, count);
400 JRT_END
401
402 address StubRoutines::select_fill_function(BasicType t, bool aligned, const char* &name) {
403 #define RETURN_STUB(xxx_fill) { \
404 name = #xxx_fill; \
405 return StubRoutines::xxx_fill(); }
406
407 switch (t) {
408 case T_BYTE:
409 case T_BOOLEAN:
410 if (!aligned) RETURN_STUB(jbyte_fill);
411 RETURN_STUB(arrayof_jbyte_fill);
412 case T_CHAR:
413 case T_SHORT:
414 if (!aligned) RETURN_STUB(jshort_fill);
415 RETURN_STUB(arrayof_jshort_fill);
416 case T_INT:
417 case T_FLOAT:
418 if (!aligned) RETURN_STUB(jint_fill);
419 RETURN_STUB(arrayof_jint_fill);
420 case T_DOUBLE:
421 case T_LONG:
422 case T_ARRAY:
423 case T_OBJECT:
424 case T_NARROWOOP:
425 case T_NARROWKLASS:
426 case T_ADDRESS:
427 case T_VOID:
428 // Currently unsupported
429 return nullptr;
430
431 default:
432 ShouldNotReachHere();
433 return nullptr;
434 }
435
436 #undef RETURN_STUB
437 }
438
439 // constants for computing the copy function
440 enum {
441 COPYFUNC_UNALIGNED = 0,
442 COPYFUNC_ALIGNED = 1, // src, dest aligned to HeapWordSize
443 COPYFUNC_CONJOINT = 0,
444 COPYFUNC_DISJOINT = 2 // src != dest, or transfer can descend
445 };
446
447 // Note: The condition "disjoint" applies also for overlapping copies
448 // where an descending copy is permitted (i.e., dest_offset <= src_offset).
449 address
450 StubRoutines::select_arraycopy_function(BasicType t, bool aligned, bool disjoint, const char* &name, bool dest_uninitialized) {
451 int selector =
452 (aligned ? COPYFUNC_ALIGNED : COPYFUNC_UNALIGNED) +
453 (disjoint ? COPYFUNC_DISJOINT : COPYFUNC_CONJOINT);
454
455 #define RETURN_STUB(xxx_arraycopy) { \
456 name = #xxx_arraycopy; \
457 return StubRoutines::xxx_arraycopy(); }
458
459 #define RETURN_STUB_PARM(xxx_arraycopy, parm) { \
460 name = parm ? #xxx_arraycopy "_uninit": #xxx_arraycopy; \
461 return StubRoutines::xxx_arraycopy(parm); }
462
463 switch (t) {
464 case T_BYTE:
465 case T_BOOLEAN:
466 switch (selector) {
467 case COPYFUNC_CONJOINT | COPYFUNC_UNALIGNED: RETURN_STUB(jbyte_arraycopy);
468 case COPYFUNC_CONJOINT | COPYFUNC_ALIGNED: RETURN_STUB(arrayof_jbyte_arraycopy);
469 case COPYFUNC_DISJOINT | COPYFUNC_UNALIGNED: RETURN_STUB(jbyte_disjoint_arraycopy);
470 case COPYFUNC_DISJOINT | COPYFUNC_ALIGNED: RETURN_STUB(arrayof_jbyte_disjoint_arraycopy);
471 }
472 case T_CHAR:
473 case T_SHORT:
474 switch (selector) {
475 case COPYFUNC_CONJOINT | COPYFUNC_UNALIGNED: RETURN_STUB(jshort_arraycopy);
476 case COPYFUNC_CONJOINT | COPYFUNC_ALIGNED: RETURN_STUB(arrayof_jshort_arraycopy);
477 case COPYFUNC_DISJOINT | COPYFUNC_UNALIGNED: RETURN_STUB(jshort_disjoint_arraycopy);
478 case COPYFUNC_DISJOINT | COPYFUNC_ALIGNED: RETURN_STUB(arrayof_jshort_disjoint_arraycopy);
479 }
480 case T_INT:
481 case T_FLOAT:
482 switch (selector) {
483 case COPYFUNC_CONJOINT | COPYFUNC_UNALIGNED: RETURN_STUB(jint_arraycopy);
484 case COPYFUNC_CONJOINT | COPYFUNC_ALIGNED: RETURN_STUB(arrayof_jint_arraycopy);
485 case COPYFUNC_DISJOINT | COPYFUNC_UNALIGNED: RETURN_STUB(jint_disjoint_arraycopy);
486 case COPYFUNC_DISJOINT | COPYFUNC_ALIGNED: RETURN_STUB(arrayof_jint_disjoint_arraycopy);
487 }
488 case T_DOUBLE:
489 case T_LONG:
490 switch (selector) {
491 case COPYFUNC_CONJOINT | COPYFUNC_UNALIGNED: RETURN_STUB(jlong_arraycopy);
492 case COPYFUNC_CONJOINT | COPYFUNC_ALIGNED: RETURN_STUB(arrayof_jlong_arraycopy);
493 case COPYFUNC_DISJOINT | COPYFUNC_UNALIGNED: RETURN_STUB(jlong_disjoint_arraycopy);
494 case COPYFUNC_DISJOINT | COPYFUNC_ALIGNED: RETURN_STUB(arrayof_jlong_disjoint_arraycopy);
495 }
496 case T_ARRAY:
497 case T_OBJECT:
498 switch (selector) {
499 case COPYFUNC_CONJOINT | COPYFUNC_UNALIGNED: RETURN_STUB_PARM(oop_arraycopy, dest_uninitialized);
500 case COPYFUNC_CONJOINT | COPYFUNC_ALIGNED: RETURN_STUB_PARM(arrayof_oop_arraycopy, dest_uninitialized);
501 case COPYFUNC_DISJOINT | COPYFUNC_UNALIGNED: RETURN_STUB_PARM(oop_disjoint_arraycopy, dest_uninitialized);
502 case COPYFUNC_DISJOINT | COPYFUNC_ALIGNED: RETURN_STUB_PARM(arrayof_oop_disjoint_arraycopy, dest_uninitialized);
503 }
504 default:
505 ShouldNotReachHere();
506 return nullptr;
507 }
508
509 #undef RETURN_STUB
510 #undef RETURN_STUB_PARM
511 }
512
513 UnsafeMemoryAccessMark::UnsafeMemoryAccessMark(StubCodeGenerator* cgen, bool add_entry, bool continue_at_scope_end, address error_exit_pc) {
514 _cgen = cgen;
515 _ucm_entry = nullptr;
516 if (add_entry) {
517 address err_exit_pc = nullptr;
518 if (!continue_at_scope_end) {
519 err_exit_pc = error_exit_pc != nullptr ? error_exit_pc : UnsafeMemoryAccess::common_exit_stub_pc();
520 }
521 assert(err_exit_pc != nullptr || continue_at_scope_end, "error exit not set");
522 _ucm_entry = UnsafeMemoryAccess::add_to_table(_cgen->assembler()->pc(), nullptr, err_exit_pc);
523 }
524 }
525
526 UnsafeMemoryAccessMark::~UnsafeMemoryAccessMark() {
527 if (_ucm_entry != nullptr) {
528 _ucm_entry->set_end_pc(_cgen->assembler()->pc());
529 if (_ucm_entry->error_exit_pc() == nullptr) {
530 _ucm_entry->set_error_exit_pc(_cgen->assembler()->pc());
531 }
532 }
533 }