1 /*
2 * Copyright (c) 1997, 2024, 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/codeBuffer.hpp"
27 #include "code/compiledIC.hpp"
28 #include "code/oopRecorder.inline.hpp"
29 #include "compiler/disassembler.hpp"
30 #include "logging/log.hpp"
31 #include "oops/klass.inline.hpp"
32 #include "oops/methodData.hpp"
33 #include "oops/oop.inline.hpp"
34 #include "runtime/icache.hpp"
35 #include "runtime/safepointVerifiers.hpp"
36 #include "utilities/align.hpp"
37 #include "utilities/copy.hpp"
38 #include "utilities/powerOfTwo.hpp"
39 #include "utilities/xmlstream.hpp"
40
41 // The structure of a CodeSection:
42 //
43 // _start -> +----------------+
44 // | machine code...|
45 // _end -> |----------------|
46 // | |
47 // | (empty) |
48 // | |
49 // | |
50 // +----------------+
51 // _limit -> | |
52 //
53 // _locs_start -> +----------------+
54 // |reloc records...|
55 // |----------------|
56 // _locs_end -> | |
57 // | |
58 // | (empty) |
59 // | |
60 // | |
61 // +----------------+
62 // _locs_limit -> | |
63 // The _end (resp. _limit) pointer refers to the first
64 // unused (resp. unallocated) byte.
65
66 // The structure of the CodeBuffer while code is being accumulated:
67 //
68 // _total_start -> \
69 // _consts._start -> +----------------+
70 // | |
71 // | Constants |
72 // | |
73 // _insts._start -> |----------------|
74 // | |
75 // | Code |
76 // | |
77 // _stubs._start -> |----------------|
78 // | |
79 // | Stubs | (also handlers for deopt/exception)
80 // | |
81 // +----------------+
82 // + _total_size -> | |
83 //
84 // When the code and relocations are copied to the code cache,
85 // the empty parts of each section are removed, and everything
86 // is copied into contiguous locations.
87
88 typedef CodeBuffer::csize_t csize_t; // file-local definition
89
90 // External buffer, in a predefined CodeBlob.
91 // Important: The code_start must be taken exactly, and not realigned.
92 CodeBuffer::CodeBuffer(CodeBlob* blob) DEBUG_ONLY(: Scrubber(this, sizeof(*this))) {
93 // Provide code buffer with meaningful name
94 initialize_misc(blob->name());
95 initialize(blob->content_begin(), blob->content_size());
96 debug_only(verify_section_allocation();)
97 }
98
99 void CodeBuffer::initialize(csize_t code_size, csize_t locs_size) {
100 // Always allow for empty slop around each section.
101 int slop = (int) CodeSection::end_slop();
102
103 assert(SECT_LIMIT == 3, "total_size explicitly lists all section alignments");
104 int total_size = code_size + _consts.alignment() + _insts.alignment() + _stubs.alignment() + SECT_LIMIT * slop;
105
106 assert(blob() == nullptr, "only once");
107 set_blob(BufferBlob::create(_name, total_size));
108 if (blob() == nullptr) {
109 // The assembler constructor will throw a fatal on an empty CodeBuffer.
110 return; // caller must test this
111 }
112
113 // Set up various pointers into the blob.
114 initialize(_total_start, _total_size);
115
116 assert((uintptr_t)insts_begin() % CodeEntryAlignment == 0, "instruction start not code entry aligned");
117
118 pd_initialize();
119
120 if (locs_size != 0) {
121 _insts.initialize_locs(locs_size / sizeof(relocInfo));
122 }
123
124 debug_only(verify_section_allocation();)
125 }
126
127
128 CodeBuffer::~CodeBuffer() {
129 verify_section_allocation();
130
131 // If we allocated our code buffer from the CodeCache via a BufferBlob, and
132 // it's not permanent, then free the BufferBlob. The rest of the memory
133 // will be freed when the ResourceObj is released.
134 for (CodeBuffer* cb = this; cb != nullptr; cb = cb->before_expand()) {
135 // Previous incarnations of this buffer are held live, so that internal
136 // addresses constructed before expansions will not be confused.
137 cb->free_blob();
138 }
139 if (_overflow_arena != nullptr) {
140 // free any overflow storage
141 delete _overflow_arena;
142 }
143 if (_shared_trampoline_requests != nullptr) {
144 delete _shared_trampoline_requests;
145 }
146
147 NOT_PRODUCT(clear_strings());
148 }
149
150 void CodeBuffer::initialize_oop_recorder(OopRecorder* r) {
151 assert(_oop_recorder == &_default_oop_recorder && _default_oop_recorder.is_unused(), "do this once");
152 DEBUG_ONLY(_default_oop_recorder.freeze()); // force unused OR to be frozen
153 _oop_recorder = r;
154 }
155
156 void CodeBuffer::initialize_section_size(CodeSection* cs, csize_t size) {
157 assert(cs != &_insts, "insts is the memory provider, not the consumer");
158 csize_t slop = CodeSection::end_slop(); // margin between sections
159 int align = cs->alignment();
160 assert(is_power_of_2(align), "sanity");
161 address start = _insts._start;
162 address limit = _insts._limit;
163 address middle = limit - size;
164 middle -= (intptr_t)middle & (align-1); // align the division point downward
165 guarantee(middle - slop > start, "need enough space to divide up");
166 _insts._limit = middle - slop; // subtract desired space, plus slop
167 cs->initialize(middle, limit - middle);
168 assert(cs->start() == middle, "sanity");
169 assert(cs->limit() == limit, "sanity");
170 // give it some relocations to start with, if the main section has them
171 if (_insts.has_locs()) cs->initialize_locs(1);
172 }
173
174 void CodeBuffer::set_blob(BufferBlob* blob) {
175 _blob = blob;
176 if (blob != nullptr) {
177 address start = blob->content_begin();
178 address end = blob->content_end();
179 // Round up the starting address.
180 int align = _insts.alignment();
181 start += (-(intptr_t)start) & (align-1);
182 _total_start = start;
183 _total_size = end - start;
184 } else {
185 #ifdef ASSERT
186 // Clean out dangling pointers.
187 _total_start = badAddress;
188 _consts._start = _consts._end = badAddress;
189 _insts._start = _insts._end = badAddress;
190 _stubs._start = _stubs._end = badAddress;
191 #endif //ASSERT
192 }
193 }
194
195 void CodeBuffer::free_blob() {
196 if (_blob != nullptr) {
197 BufferBlob::free(_blob);
198 set_blob(nullptr);
199 }
200 }
201
202 const char* CodeBuffer::code_section_name(int n) {
203 #ifdef PRODUCT
204 return nullptr;
205 #else //PRODUCT
206 switch (n) {
207 case SECT_CONSTS: return "consts";
208 case SECT_INSTS: return "insts";
209 case SECT_STUBS: return "stubs";
210 default: return nullptr;
211 }
212 #endif //PRODUCT
213 }
214
215 int CodeBuffer::section_index_of(address addr) const {
216 for (int n = 0; n < (int)SECT_LIMIT; n++) {
217 const CodeSection* cs = code_section(n);
218 if (cs->allocates(addr)) return n;
219 }
220 return SECT_NONE;
221 }
222
223 int CodeBuffer::locator(address addr) const {
224 for (int n = 0; n < (int)SECT_LIMIT; n++) {
225 const CodeSection* cs = code_section(n);
226 if (cs->allocates(addr)) {
227 return locator(addr - cs->start(), n);
228 }
229 }
230 return -1;
231 }
232
233
234 bool CodeBuffer::is_backward_branch(Label& L) {
235 return L.is_bound() && insts_end() <= locator_address(L.loc());
236 }
237
238 #ifndef PRODUCT
239 address CodeBuffer::decode_begin() {
240 address begin = _insts.start();
241 if (_decode_begin != nullptr && _decode_begin > begin)
242 begin = _decode_begin;
243 return begin;
244 }
245 #endif // !PRODUCT
246
247 GrowableArray<int>* CodeBuffer::create_patch_overflow() {
248 if (_overflow_arena == nullptr) {
249 _overflow_arena = new (mtCode) Arena(mtCode);
250 }
251 return new (_overflow_arena) GrowableArray<int>(_overflow_arena, 8, 0, 0);
252 }
253
254
255 // Helper function for managing labels and their target addresses.
256 // Returns a sensible address, and if it is not the label's final
257 // address, notes the dependency (at 'branch_pc') on the label.
258 address CodeSection::target(Label& L, address branch_pc) {
259 if (L.is_bound()) {
260 int loc = L.loc();
261 if (index() == CodeBuffer::locator_sect(loc)) {
262 return start() + CodeBuffer::locator_pos(loc);
263 } else {
264 return outer()->locator_address(loc);
265 }
266 } else {
267 assert(allocates2(branch_pc), "sanity");
268 address base = start();
269 int patch_loc = CodeBuffer::locator(branch_pc - base, index());
270 L.add_patch_at(outer(), patch_loc);
271
272 // Need to return a pc, doesn't matter what it is since it will be
273 // replaced during resolution later.
274 // Don't return null or badAddress, since branches shouldn't overflow.
275 // Don't return base either because that could overflow displacements
276 // for shorter branches. It will get checked when bound.
277 return branch_pc;
278 }
279 }
280
281 void CodeSection::relocate(address at, relocInfo::relocType rtype, int format, jint method_index) {
282 RelocationHolder rh;
283 switch (rtype) {
284 case relocInfo::none: return;
285 case relocInfo::opt_virtual_call_type: {
286 rh = opt_virtual_call_Relocation::spec(method_index);
287 break;
288 }
289 case relocInfo::static_call_type: {
290 rh = static_call_Relocation::spec(method_index);
291 break;
292 }
293 case relocInfo::virtual_call_type: {
294 assert(method_index == 0, "resolved method overriding is not supported");
295 rh = Relocation::spec_simple(rtype);
296 break;
297 }
298 default: {
299 rh = Relocation::spec_simple(rtype);
300 break;
301 }
302 }
303 relocate(at, rh, format);
304 }
305
306 void CodeSection::relocate(address at, RelocationHolder const& spec, int format) {
307 // Do not relocate in scratch buffers.
308 if (scratch_emit()) { return; }
309 Relocation* reloc = spec.reloc();
310 relocInfo::relocType rtype = (relocInfo::relocType) reloc->type();
311 if (rtype == relocInfo::none) return;
312
313 // The assertion below has been adjusted, to also work for
314 // relocation for fixup. Sometimes we want to put relocation
315 // information for the next instruction, since it will be patched
316 // with a call.
317 assert(start() <= at && at <= end()+1,
318 "cannot relocate data outside code boundaries");
319
320 if (!has_locs()) {
321 // no space for relocation information provided => code cannot be
322 // relocated. Make sure that relocate is only called with rtypes
323 // that can be ignored for this kind of code.
324 assert(rtype == relocInfo::none ||
325 rtype == relocInfo::runtime_call_type ||
326 rtype == relocInfo::internal_word_type||
327 rtype == relocInfo::section_word_type ||
328 rtype == relocInfo::external_word_type||
329 rtype == relocInfo::barrier_type,
330 "code needs relocation information");
331 // leave behind an indication that we attempted a relocation
332 DEBUG_ONLY(_locs_start = _locs_limit = (relocInfo*)badAddress);
333 return;
334 }
335
336 // Advance the point, noting the offset we'll have to record.
337 csize_t offset = at - locs_point();
338 set_locs_point(at);
339
340 // Test for a couple of overflow conditions; maybe expand the buffer.
341 relocInfo* end = locs_end();
342 relocInfo* req = end + relocInfo::length_limit;
343 // Check for (potential) overflow
344 if (req >= locs_limit() || offset >= relocInfo::offset_limit()) {
345 req += (uint)offset / (uint)relocInfo::offset_limit();
346 if (req >= locs_limit()) {
347 // Allocate or reallocate.
348 expand_locs(locs_count() + (req - end));
349 // reload pointer
350 end = locs_end();
351 }
352 }
353
354 // If the offset is giant, emit filler relocs, of type 'none', but
355 // each carrying the largest possible offset, to advance the locs_point.
356 while (offset >= relocInfo::offset_limit()) {
357 assert(end < locs_limit(), "adjust previous paragraph of code");
358 *end++ = relocInfo::filler_info();
359 offset -= relocInfo::filler_info().addr_offset();
360 }
361
362 // If it's a simple reloc with no data, we'll just write (rtype | offset).
363 (*end) = relocInfo(rtype, offset, format);
364
365 // If it has data, insert the prefix, as (data_prefix_tag | data1), data2.
366 end->initialize(this, reloc);
367 }
368
369 void CodeSection::initialize_locs(int locs_capacity) {
370 assert(_locs_start == nullptr, "only one locs init step, please");
371 // Apply a priori lower limits to relocation size:
372 csize_t min_locs = MAX2(size() / 16, (csize_t)4);
373 if (locs_capacity < min_locs) locs_capacity = min_locs;
374 relocInfo* locs_start = NEW_RESOURCE_ARRAY(relocInfo, locs_capacity);
375 _locs_start = locs_start;
376 _locs_end = locs_start;
377 _locs_limit = locs_start + locs_capacity;
378 _locs_own = true;
379 }
380
381 void CodeSection::initialize_shared_locs(relocInfo* buf, int length) {
382 assert(_locs_start == nullptr, "do this before locs are allocated");
383 // Internal invariant: locs buf must be fully aligned.
384 // See copy_relocations_to() below.
385 while ((uintptr_t)buf % HeapWordSize != 0 && length > 0) {
386 ++buf; --length;
387 }
388 if (length > 0) {
389 _locs_start = buf;
390 _locs_end = buf;
391 _locs_limit = buf + length;
392 _locs_own = false;
393 }
394 }
395
396 void CodeSection::initialize_locs_from(const CodeSection* source_cs) {
397 int lcount = source_cs->locs_count();
398 if (lcount != 0) {
399 initialize_shared_locs(source_cs->locs_start(), lcount);
400 _locs_end = _locs_limit = _locs_start + lcount;
401 assert(is_allocated(), "must have copied code already");
402 set_locs_point(start() + source_cs->locs_point_off());
403 }
404 assert(this->locs_count() == source_cs->locs_count(), "sanity");
405 }
406
407 void CodeSection::expand_locs(int new_capacity) {
408 if (_locs_start == nullptr) {
409 initialize_locs(new_capacity);
410 return;
411 } else {
412 int old_count = locs_count();
413 int old_capacity = locs_capacity();
414 if (new_capacity < old_capacity * 2)
415 new_capacity = old_capacity * 2;
416 relocInfo* locs_start;
417 if (_locs_own) {
418 locs_start = REALLOC_RESOURCE_ARRAY(relocInfo, _locs_start, old_capacity, new_capacity);
419 } else {
420 locs_start = NEW_RESOURCE_ARRAY(relocInfo, new_capacity);
421 Copy::conjoint_jbytes(_locs_start, locs_start, old_capacity * sizeof(relocInfo));
422 _locs_own = true;
423 }
424 _locs_start = locs_start;
425 _locs_end = locs_start + old_count;
426 _locs_limit = locs_start + new_capacity;
427 }
428 }
429
430 int CodeSection::alignment() const {
431 if (_index == CodeBuffer::SECT_CONSTS) {
432 // CodeBuffer controls the alignment of the constants section
433 return _outer->_const_section_alignment;
434 }
435 if (_index == CodeBuffer::SECT_INSTS) {
436 return (int) CodeEntryAlignment;
437 }
438 if (_index == CodeBuffer::SECT_STUBS) {
439 // CodeBuffer installer expects sections to be HeapWordSize aligned
440 return HeapWordSize;
441 }
442 ShouldNotReachHere();
443 return 0;
444 }
445
446 /// Support for emitting the code to its final location.
447 /// The pattern is the same for all functions.
448 /// We iterate over all the sections, padding each to alignment.
449
450 csize_t CodeBuffer::total_content_size() const {
451 csize_t size_so_far = 0;
452 for (int n = 0; n < (int)SECT_LIMIT; n++) {
453 const CodeSection* cs = code_section(n);
454 if (cs->is_empty()) continue; // skip trivial section
455 size_so_far = cs->align_at_start(size_so_far);
456 size_so_far += cs->size();
457 }
458 return size_so_far;
459 }
460
461 void CodeBuffer::compute_final_layout(CodeBuffer* dest) const {
462 address buf = dest->_total_start;
463 csize_t buf_offset = 0;
464 assert(dest->_total_size >= total_content_size(), "must be big enough");
465 assert(!_finalize_stubs, "non-finalized stubs");
466
467 {
468 // not sure why this is here, but why not...
469 int alignSize = MAX2((intx) sizeof(jdouble), CodeEntryAlignment);
470 assert( (dest->_total_start - _insts.start()) % alignSize == 0, "copy must preserve alignment");
471 }
472
473 const CodeSection* prev_cs = nullptr;
474 CodeSection* prev_dest_cs = nullptr;
475
476 for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) {
477 // figure compact layout of each section
478 const CodeSection* cs = code_section(n);
479 csize_t csize = cs->size();
480
481 CodeSection* dest_cs = dest->code_section(n);
482 if (!cs->is_empty()) {
483 // Compute initial padding; assign it to the previous non-empty guy.
484 // Cf. figure_expanded_capacities.
485 csize_t padding = cs->align_at_start(buf_offset) - buf_offset;
486 if (prev_dest_cs != nullptr) {
487 if (padding != 0) {
488 buf_offset += padding;
489 prev_dest_cs->_limit += padding;
490 }
491 } else {
492 guarantee(padding == 0, "In first iteration no padding should be needed.");
493 }
494 prev_dest_cs = dest_cs;
495 prev_cs = cs;
496 }
497
498 debug_only(dest_cs->_start = nullptr); // defeat double-initialization assert
499 dest_cs->initialize(buf+buf_offset, csize);
500 dest_cs->set_end(buf+buf_offset+csize);
501 assert(dest_cs->is_allocated(), "must always be allocated");
502 assert(cs->is_empty() == dest_cs->is_empty(), "sanity");
503
504 buf_offset += csize;
505 }
506
507 // Done calculating sections; did it come out to the right end?
508 assert(buf_offset == total_content_size(), "sanity");
509 debug_only(dest->verify_section_allocation();)
510 }
511
512 // Append an oop reference that keeps the class alive.
513 static void append_oop_references(GrowableArray<oop>* oops, Klass* k) {
514 oop cl = k->klass_holder();
515 if (cl != nullptr && !oops->contains(cl)) {
516 oops->append(cl);
517 }
518 }
519
520 void CodeBuffer::finalize_oop_references(const methodHandle& mh) {
521 NoSafepointVerifier nsv;
522
523 GrowableArray<oop> oops;
524
525 // Make sure that immediate metadata records something in the OopRecorder
526 for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) {
527 // pull code out of each section
528 CodeSection* cs = code_section(n);
529 if (cs->is_empty() || (cs->locs_count() == 0)) continue; // skip trivial section
530 RelocIterator iter(cs);
531 while (iter.next()) {
532 if (iter.type() == relocInfo::metadata_type) {
533 metadata_Relocation* md = iter.metadata_reloc();
534 if (md->metadata_is_immediate()) {
535 Metadata* m = md->metadata_value();
536 if (oop_recorder()->is_real(m)) {
537 if (m->is_methodData()) {
538 m = ((MethodData*)m)->method();
539 }
540 if (m->is_method()) {
541 m = ((Method*)m)->method_holder();
542 }
543 if (m->is_klass()) {
544 append_oop_references(&oops, (Klass*)m);
545 } else {
546 // XXX This will currently occur for MDO which don't
547 // have a backpointer. This has to be fixed later.
548 m->print();
549 ShouldNotReachHere();
550 }
551 }
552 }
553 }
554 }
555 }
556
557 if (!oop_recorder()->is_unused()) {
558 for (int i = 0; i < oop_recorder()->metadata_count(); i++) {
559 Metadata* m = oop_recorder()->metadata_at(i);
560 if (oop_recorder()->is_real(m)) {
561 if (m->is_methodData()) {
562 m = ((MethodData*)m)->method();
563 }
564 if (m->is_method()) {
565 m = ((Method*)m)->method_holder();
566 }
567 if (m->is_klass()) {
568 append_oop_references(&oops, (Klass*)m);
569 } else {
570 m->print();
571 ShouldNotReachHere();
572 }
573 }
574 }
575
576 }
577
578 // Add the class loader of Method* for the nmethod itself
579 append_oop_references(&oops, mh->method_holder());
580
581 // Add any oops that we've found
582 Thread* thread = Thread::current();
583 for (int i = 0; i < oops.length(); i++) {
584 oop_recorder()->find_index((jobject)thread->handle_area()->allocate_handle(oops.at(i)));
585 }
586 }
587
588
589
590 csize_t CodeBuffer::total_offset_of(const CodeSection* cs) const {
591 csize_t size_so_far = 0;
592 for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) {
593 const CodeSection* cur_cs = code_section(n);
594 if (!cur_cs->is_empty()) {
595 size_so_far = cur_cs->align_at_start(size_so_far);
596 }
597 if (cur_cs->index() == cs->index()) {
598 return size_so_far;
599 }
600 size_so_far += cur_cs->size();
601 }
602 ShouldNotReachHere();
603 return -1;
604 }
605
606 int CodeBuffer::total_skipped_instructions_size() const {
607 int total_skipped_size = 0;
608 for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) {
609 const CodeSection* cur_cs = code_section(n);
610 if (!cur_cs->is_empty()) {
611 total_skipped_size += cur_cs->_skipped_instructions_size;
612 }
613 }
614 return total_skipped_size;
615 }
616
617 csize_t CodeBuffer::total_relocation_size() const {
618 csize_t total = copy_relocations_to(nullptr); // dry run only
619 return (csize_t) align_up(total, HeapWordSize);
620 }
621
622 csize_t CodeBuffer::copy_relocations_to(address buf, csize_t buf_limit, bool only_inst) const {
623 csize_t buf_offset = 0;
624 csize_t code_end_so_far = 0;
625 csize_t code_point_so_far = 0;
626
627 assert((uintptr_t)buf % HeapWordSize == 0, "buf must be fully aligned");
628 assert(buf_limit % HeapWordSize == 0, "buf must be evenly sized");
629
630 for (int n = (int) SECT_FIRST; n < (int)SECT_LIMIT; n++) {
631 if (only_inst && (n != (int)SECT_INSTS)) {
632 // Need only relocation info for code.
633 continue;
634 }
635 // pull relocs out of each section
636 const CodeSection* cs = code_section(n);
637 assert(!(cs->is_empty() && cs->locs_count() > 0), "sanity");
638 if (cs->is_empty()) continue; // skip trivial section
639 relocInfo* lstart = cs->locs_start();
640 relocInfo* lend = cs->locs_end();
641 csize_t lsize = (csize_t)( (address)lend - (address)lstart );
642 csize_t csize = cs->size();
643 code_end_so_far = cs->align_at_start(code_end_so_far);
644
645 if (lsize > 0) {
646 // Figure out how to advance the combined relocation point
647 // first to the beginning of this section.
648 // We'll insert one or more filler relocs to span that gap.
649 // (Don't bother to improve this by editing the first reloc's offset.)
650 csize_t new_code_point = code_end_so_far;
651 for (csize_t jump;
652 code_point_so_far < new_code_point;
653 code_point_so_far += jump) {
654 jump = new_code_point - code_point_so_far;
655 relocInfo filler = relocInfo::filler_info();
656 if (jump >= filler.addr_offset()) {
657 jump = filler.addr_offset();
658 } else { // else shrink the filler to fit
659 filler = relocInfo(relocInfo::none, jump);
660 }
661 if (buf != nullptr) {
662 assert(buf_offset + (csize_t)sizeof(filler) <= buf_limit, "filler in bounds");
663 *(relocInfo*)(buf+buf_offset) = filler;
664 }
665 buf_offset += sizeof(filler);
666 }
667
668 // Update code point and end to skip past this section:
669 csize_t last_code_point = code_end_so_far + cs->locs_point_off();
670 assert(code_point_so_far <= last_code_point, "sanity");
671 code_point_so_far = last_code_point; // advance past this guy's relocs
672 }
673 code_end_so_far += csize; // advance past this guy's instructions too
674
675 // Done with filler; emit the real relocations:
676 if (buf != nullptr && lsize != 0) {
677 assert(buf_offset + lsize <= buf_limit, "target in bounds");
678 assert((uintptr_t)lstart % HeapWordSize == 0, "sane start");
679 if (buf_offset % HeapWordSize == 0) {
680 // Use wordwise copies if possible:
681 Copy::disjoint_words((HeapWord*)lstart,
682 (HeapWord*)(buf+buf_offset),
683 (lsize + HeapWordSize-1) / HeapWordSize);
684 } else {
685 Copy::conjoint_jbytes(lstart, buf+buf_offset, lsize);
686 }
687 }
688 buf_offset += lsize;
689 }
690
691 // Align end of relocation info in target.
692 while (buf_offset % HeapWordSize != 0) {
693 if (buf != nullptr) {
694 relocInfo padding = relocInfo(relocInfo::none, 0);
695 assert(buf_offset + (csize_t)sizeof(padding) <= buf_limit, "padding in bounds");
696 *(relocInfo*)(buf+buf_offset) = padding;
697 }
698 buf_offset += sizeof(relocInfo);
699 }
700
701 assert(only_inst || code_end_so_far == total_content_size(), "sanity");
702
703 return buf_offset;
704 }
705
706 csize_t CodeBuffer::copy_relocations_to(CodeBlob* dest) const {
707 address buf = nullptr;
708 csize_t buf_offset = 0;
709 csize_t buf_limit = 0;
710
711 if (dest != nullptr) {
712 buf = (address)dest->relocation_begin();
713 buf_limit = (address)dest->relocation_end() - buf;
714 }
715 // if dest is null, this is just the sizing pass
716 //
717 buf_offset = copy_relocations_to(buf, buf_limit, false);
718
719 return buf_offset;
720 }
721
722 void CodeBuffer::copy_code_to(CodeBlob* dest_blob) {
723 #ifndef PRODUCT
724 if (PrintNMethods && (WizardMode || Verbose)) {
725 tty->print("done with CodeBuffer:");
726 ((CodeBuffer*)this)->print();
727 }
728 #endif //PRODUCT
729
730 CodeBuffer dest(dest_blob);
731 assert(dest_blob->content_size() >= total_content_size(), "good sizing");
732 this->compute_final_layout(&dest);
733
734 // Set beginning of constant table before relocating.
735 dest_blob->set_ctable_begin(dest.consts()->start());
736
737 relocate_code_to(&dest);
738
739 // Share assembly remarks and debug strings with the blob.
740 NOT_PRODUCT(dest_blob->use_remarks(_asm_remarks));
741 NOT_PRODUCT(dest_blob->use_strings(_dbg_strings));
742
743 // Done moving code bytes; were they the right size?
744 assert((int)align_up(dest.total_content_size(), oopSize) == dest_blob->content_size(), "sanity");
745
746 // Flush generated code
747 ICache::invalidate_range(dest_blob->code_begin(), dest_blob->code_size());
748 }
749
750 // Move all my code into another code buffer. Consult applicable
751 // relocs to repair embedded addresses. The layout in the destination
752 // CodeBuffer is different to the source CodeBuffer: the destination
753 // CodeBuffer gets the final layout (consts, insts, stubs in order of
754 // ascending address).
755 void CodeBuffer::relocate_code_to(CodeBuffer* dest) const {
756 address dest_end = dest->_total_start + dest->_total_size;
757 address dest_filled = nullptr;
758 for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) {
759 // pull code out of each section
760 const CodeSection* cs = code_section(n);
761 if (cs->is_empty()) continue; // skip trivial section
762 CodeSection* dest_cs = dest->code_section(n);
763 assert(cs->size() == dest_cs->size(), "sanity");
764 csize_t usize = dest_cs->size();
765 csize_t wsize = align_up(usize, HeapWordSize);
766 assert(dest_cs->start() + wsize <= dest_end, "no overflow");
767 // Copy the code as aligned machine words.
768 // This may also include an uninitialized partial word at the end.
769 Copy::disjoint_words((HeapWord*)cs->start(),
770 (HeapWord*)dest_cs->start(),
771 wsize / HeapWordSize);
772
773 if (dest->blob() == nullptr) {
774 // Destination is a final resting place, not just another buffer.
775 // Normalize uninitialized bytes in the final padding.
776 Copy::fill_to_bytes(dest_cs->end(), dest_cs->remaining(),
777 Assembler::code_fill_byte());
778 }
779 // Keep track of the highest filled address
780 dest_filled = MAX2(dest_filled, dest_cs->end() + dest_cs->remaining());
781
782 assert(cs->locs_start() != (relocInfo*)badAddress,
783 "this section carries no reloc storage, but reloc was attempted");
784
785 // Make the new code copy use the old copy's relocations:
786 dest_cs->initialize_locs_from(cs);
787 }
788
789 // Do relocation after all sections are copied.
790 // This is necessary if the code uses constants in stubs, which are
791 // relocated when the corresponding instruction in the code (e.g., a
792 // call) is relocated. Stubs are placed behind the main code
793 // section, so that section has to be copied before relocating.
794 for (int n = (int) SECT_FIRST; n < (int)SECT_LIMIT; n++) {
795 CodeSection* dest_cs = dest->code_section(n);
796 if (dest_cs->is_empty() || (dest_cs->locs_count() == 0)) continue; // skip trivial section
797 { // Repair the pc relative information in the code after the move
798 RelocIterator iter(dest_cs);
799 while (iter.next()) {
800 iter.reloc()->fix_relocation_after_move(this, dest);
801 }
802 }
803 }
804
805 if (dest->blob() == nullptr && dest_filled != nullptr) {
806 // Destination is a final resting place, not just another buffer.
807 // Normalize uninitialized bytes in the final padding.
808 Copy::fill_to_bytes(dest_filled, dest_end - dest_filled,
809 Assembler::code_fill_byte());
810
811 }
812 }
813
814 csize_t CodeBuffer::figure_expanded_capacities(CodeSection* which_cs,
815 csize_t amount,
816 csize_t* new_capacity) {
817 csize_t new_total_cap = 0;
818
819 for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) {
820 const CodeSection* sect = code_section(n);
821
822 if (!sect->is_empty()) {
823 // Compute initial padding; assign it to the previous section,
824 // even if it's empty (e.g. consts section can be empty).
825 // Cf. compute_final_layout
826 csize_t padding = sect->align_at_start(new_total_cap) - new_total_cap;
827 if (padding != 0) {
828 new_total_cap += padding;
829 assert(n - 1 >= SECT_FIRST, "sanity");
830 new_capacity[n - 1] += padding;
831 }
832 }
833
834 csize_t exp = sect->size(); // 100% increase
835 if ((uint)exp < 4*K) exp = 4*K; // minimum initial increase
836 if (sect == which_cs) {
837 if (exp < amount) exp = amount;
838 if (StressCodeBuffers) exp = amount; // expand only slightly
839 } else if (n == SECT_INSTS) {
840 // scale down inst increases to a more modest 25%
841 exp = 4*K + ((exp - 4*K) >> 2);
842 if (StressCodeBuffers) exp = amount / 2; // expand only slightly
843 } else if (sect->is_empty()) {
844 // do not grow an empty secondary section
845 exp = 0;
846 }
847 // Allow for inter-section slop:
848 exp += CodeSection::end_slop();
849 csize_t new_cap = sect->size() + exp;
850 if (new_cap < sect->capacity()) {
851 // No need to expand after all.
852 new_cap = sect->capacity();
853 }
854 new_capacity[n] = new_cap;
855 new_total_cap += new_cap;
856 }
857
858 return new_total_cap;
859 }
860
861 void CodeBuffer::expand(CodeSection* which_cs, csize_t amount) {
862 #ifndef PRODUCT
863 if (PrintNMethods && (WizardMode || Verbose)) {
864 tty->print("expanding CodeBuffer:");
865 this->print();
866 }
867
868 if (StressCodeBuffers && blob() != nullptr) {
869 static int expand_count = 0;
870 if (expand_count >= 0) expand_count += 1;
871 if (expand_count > 100 && is_power_of_2(expand_count)) {
872 tty->print_cr("StressCodeBuffers: have expanded %d times", expand_count);
873 // simulate an occasional allocation failure:
874 free_blob();
875 }
876 }
877 #endif //PRODUCT
878
879 // Resizing must be allowed
880 {
881 if (blob() == nullptr) return; // caller must check if blob is null
882 }
883
884 // Figure new capacity for each section.
885 csize_t new_capacity[SECT_LIMIT];
886 memset(new_capacity, 0, sizeof(csize_t) * SECT_LIMIT);
887 csize_t new_total_cap
888 = figure_expanded_capacities(which_cs, amount, new_capacity);
889
890 // Create a new (temporary) code buffer to hold all the new data
891 CodeBuffer cb(name(), new_total_cap, 0);
892 if (cb.blob() == nullptr) {
893 // Failed to allocate in code cache.
894 free_blob();
895 return;
896 }
897
898 // Create an old code buffer to remember which addresses used to go where.
899 // This will be useful when we do final assembly into the code cache,
900 // because we will need to know how to warp any internal address that
901 // has been created at any time in this CodeBuffer's past.
902 CodeBuffer* bxp = new CodeBuffer(_total_start, _total_size);
903 bxp->take_over_code_from(this); // remember the old undersized blob
904 DEBUG_ONLY(this->_blob = nullptr); // silence a later assert
905 bxp->_before_expand = this->_before_expand;
906 this->_before_expand = bxp;
907
908 // Give each section its required (expanded) capacity.
909 for (int n = (int)SECT_LIMIT-1; n >= SECT_FIRST; n--) {
910 CodeSection* cb_sect = cb.code_section(n);
911 CodeSection* this_sect = code_section(n);
912 if (new_capacity[n] == 0) continue; // already nulled out
913 if (n != SECT_INSTS) {
914 cb.initialize_section_size(cb_sect, new_capacity[n]);
915 }
916 assert(cb_sect->capacity() >= new_capacity[n], "big enough");
917 address cb_start = cb_sect->start();
918 cb_sect->set_end(cb_start + this_sect->size());
919 if (this_sect->mark() == nullptr) {
920 cb_sect->clear_mark();
921 } else {
922 cb_sect->set_mark(cb_start + this_sect->mark_off());
923 }
924 }
925
926 // Needs to be initialized when calling fix_relocation_after_move.
927 cb.blob()->set_ctable_begin(cb.consts()->start());
928
929 // Move all the code and relocations to the new blob:
930 relocate_code_to(&cb);
931
932 // some internal addresses, _last_insn _last_label, are used during code emission,
933 // adjust them in expansion
934 adjust_internal_address(insts_begin(), cb.insts_begin());
935
936 // Copy the temporary code buffer into the current code buffer.
937 // Basically, do {*this = cb}, except for some control information.
938 this->take_over_code_from(&cb);
939 cb.set_blob(nullptr);
940
941 // Zap the old code buffer contents, to avoid mistakenly using them.
942 debug_only(Copy::fill_to_bytes(bxp->_total_start, bxp->_total_size,
943 badCodeHeapFreeVal);)
944
945 // Make certain that the new sections are all snugly inside the new blob.
946 debug_only(verify_section_allocation();)
947
948 #ifndef PRODUCT
949 _decode_begin = nullptr; // sanity
950 if (PrintNMethods && (WizardMode || Verbose)) {
951 tty->print("expanded CodeBuffer:");
952 this->print();
953 }
954 #endif //PRODUCT
955 }
956
957 void CodeBuffer::adjust_internal_address(address from, address to) {
958 if (_last_insn != nullptr) {
959 _last_insn += to - from;
960 }
961 if (_last_label != nullptr) {
962 _last_label += to - from;
963 }
964 }
965
966 void CodeBuffer::take_over_code_from(CodeBuffer* cb) {
967 // Must already have disposed of the old blob somehow.
968 assert(blob() == nullptr, "must be empty");
969 // Take the new blob away from cb.
970 set_blob(cb->blob());
971 // Take over all the section pointers.
972 for (int n = 0; n < (int)SECT_LIMIT; n++) {
973 CodeSection* cb_sect = cb->code_section(n);
974 CodeSection* this_sect = code_section(n);
975 this_sect->take_over_code_from(cb_sect);
976 }
977 // Make sure the old cb won't try to use it or free it.
978 DEBUG_ONLY(cb->_blob = (BufferBlob*)badAddress);
979 }
980
981 void CodeBuffer::verify_section_allocation() {
982 address tstart = _total_start;
983 if (tstart == badAddress) return; // smashed by set_blob(nullptr)
984 address tend = tstart + _total_size;
985 if (_blob != nullptr) {
986 guarantee(tstart >= _blob->content_begin(), "sanity");
987 guarantee(tend <= _blob->content_end(), "sanity");
988 }
989 // Verify disjointness.
990 for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) {
991 CodeSection* sect = code_section(n);
992 if (!sect->is_allocated() || sect->is_empty()) {
993 continue;
994 }
995 guarantee(_blob == nullptr || is_aligned(sect->start(), sect->alignment()),
996 "start is aligned");
997 for (int m = n + 1; m < (int) SECT_LIMIT; m++) {
998 CodeSection* other = code_section(m);
999 if (!other->is_allocated() || other == sect) {
1000 continue;
1001 }
1002 guarantee(other->disjoint(sect), "sanity");
1003 }
1004 guarantee(sect->end() <= tend, "sanity");
1005 guarantee(sect->end() <= sect->limit(), "sanity");
1006 }
1007 }
1008
1009 void CodeBuffer::log_section_sizes(const char* name) {
1010 if (xtty != nullptr) {
1011 ttyLocker ttyl;
1012 // log info about buffer usage
1013 xtty->print_cr("<blob name='%s' total_size='%d'>", name, _total_size);
1014 for (int n = (int) CodeBuffer::SECT_FIRST; n < (int) CodeBuffer::SECT_LIMIT; n++) {
1015 CodeSection* sect = code_section(n);
1016 if (!sect->is_allocated() || sect->is_empty()) continue;
1017 xtty->print_cr("<sect index='%d' capacity='%d' size='%d' remaining='%d'/>",
1018 n, sect->capacity(), sect->size(), sect->remaining());
1019 }
1020 xtty->print_cr("</blob>");
1021 }
1022 }
1023
1024 bool CodeBuffer::finalize_stubs() {
1025 if (_finalize_stubs && !pd_finalize_stubs()) {
1026 // stub allocation failure
1027 return false;
1028 }
1029 _finalize_stubs = false;
1030 return true;
1031 }
1032
1033 void CodeBuffer::shared_stub_to_interp_for(ciMethod* callee, csize_t call_offset) {
1034 if (_shared_stub_to_interp_requests == nullptr) {
1035 _shared_stub_to_interp_requests = new SharedStubToInterpRequests(8);
1036 }
1037 SharedStubToInterpRequest request(callee, call_offset);
1038 _shared_stub_to_interp_requests->push(request);
1039 _finalize_stubs = true;
1040 }
1041
1042 #ifndef PRODUCT
1043 void CodeBuffer::block_comment(ptrdiff_t offset, const char* comment) {
1044 if (_collect_comments) {
1045 const char* str = _asm_remarks.insert(offset, comment);
1046 postcond(str != comment);
1047 }
1048 }
1049
1050 const char* CodeBuffer::code_string(const char* str) {
1051 const char* tmp = _dbg_strings.insert(str);
1052 postcond(tmp != str);
1053 return tmp;
1054 }
1055
1056 void CodeBuffer::decode() {
1057 ttyLocker ttyl;
1058 Disassembler::decode(decode_begin(), insts_end(), tty NOT_PRODUCT(COMMA &asm_remarks()));
1059 _decode_begin = insts_end();
1060 }
1061
1062 void CodeSection::print(const char* name) {
1063 csize_t locs_size = locs_end() - locs_start();
1064 tty->print_cr(" %7s.code = " PTR_FORMAT " : " PTR_FORMAT " : " PTR_FORMAT " (%d of %d)",
1065 name, p2i(start()), p2i(end()), p2i(limit()), size(), capacity());
1066 tty->print_cr(" %7s.locs = " PTR_FORMAT " : " PTR_FORMAT " : " PTR_FORMAT " (%d of %d) point=%d",
1067 name, p2i(locs_start()), p2i(locs_end()), p2i(locs_limit()), locs_size, locs_capacity(), locs_point_off());
1068 if (PrintRelocations && (locs_size != 0)) {
1069 RelocIterator iter(this);
1070 iter.print();
1071 }
1072 }
1073
1074 void CodeBuffer::print() {
1075 tty->print_cr("CodeBuffer:");
1076 for (int n = 0; n < (int)SECT_LIMIT; n++) {
1077 // print each section
1078 CodeSection* cs = code_section(n);
1079 cs->print(code_section_name(n));
1080 }
1081 }
1082
1083 // ----- CHeapString -----------------------------------------------------------
1084
1085 class CHeapString : public CHeapObj<mtCode> {
1086 public:
1087 CHeapString(const char* str) : _string(os::strdup(str)) {}
1088 ~CHeapString() {
1089 os::free((void*)_string);
1090 _string = nullptr;
1091 }
1092 const char* string() const { return _string; }
1093
1094 private:
1095 const char* _string;
1096 };
1097
1098 // ----- AsmRemarkCollection ---------------------------------------------------
1099
1100 class AsmRemarkCollection : public CHeapObj<mtCode> {
1101 public:
1102 AsmRemarkCollection() : _ref_cnt(1), _remarks(nullptr), _next(nullptr) {}
1103 ~AsmRemarkCollection() {
1104 assert(is_empty(), "Must 'clear()' before deleting!");
1105 assert(_ref_cnt == 0, "No uses must remain when deleting!");
1106 }
1107 AsmRemarkCollection* reuse() {
1108 precond(_ref_cnt > 0);
1109 return _ref_cnt++, this;
1110 }
1111
1112 const char* insert(uint offset, const char* remark);
1113 const char* lookup(uint offset) const;
1114 const char* next(uint offset) const;
1115
1116 bool is_empty() const { return _remarks == nullptr; }
1117 uint clear();
1118
1119 private:
1120 struct Cell : CHeapString {
1121 Cell(const char* remark, uint offset) :
1122 CHeapString(remark), offset(offset), prev(nullptr), next(nullptr) {}
1123 void push_back(Cell* cell) {
1124 Cell* head = this;
1125 Cell* tail = prev;
1126 tail->next = cell;
1127 cell->next = head;
1128 cell->prev = tail;
1129 prev = cell;
1130 }
1131 uint offset;
1132 Cell* prev;
1133 Cell* next;
1134 };
1135 uint _ref_cnt;
1136 Cell* _remarks;
1137 // Using a 'mutable' iteration pointer to allow 'const' on lookup/next (that
1138 // does not change the state of the list per se), supportig a simplistic
1139 // iteration scheme.
1140 mutable Cell* _next;
1141 };
1142
1143 // ----- DbgStringCollection ---------------------------------------------------
1144
1145 class DbgStringCollection : public CHeapObj<mtCode> {
1146 public:
1147 DbgStringCollection() : _ref_cnt(1), _strings(nullptr) {}
1148 ~DbgStringCollection() {
1149 assert(is_empty(), "Must 'clear()' before deleting!");
1150 assert(_ref_cnt == 0, "No uses must remain when deleting!");
1151 }
1152 DbgStringCollection* reuse() {
1153 precond(_ref_cnt > 0);
1154 return _ref_cnt++, this;
1155 }
1156
1157 const char* insert(const char* str);
1158 const char* lookup(const char* str) const;
1159
1160 bool is_empty() const { return _strings == nullptr; }
1161 uint clear();
1162
1163 private:
1164 struct Cell : CHeapString {
1165 Cell(const char* dbgstr) :
1166 CHeapString(dbgstr), prev(nullptr), next(nullptr) {}
1167 void push_back(Cell* cell) {
1168 Cell* head = this;
1169 Cell* tail = prev;
1170 tail->next = cell;
1171 cell->next = head;
1172 cell->prev = tail;
1173 prev = cell;
1174 }
1175 Cell* prev;
1176 Cell* next;
1177 };
1178 uint _ref_cnt;
1179 Cell* _strings;
1180 };
1181
1182 // ----- AsmRemarks ------------------------------------------------------------
1183 //
1184 // Acting as interface to reference counted mapping [offset -> remark], where
1185 // offset is a byte offset into an instruction stream (CodeBuffer, CodeBlob or
1186 // other memory buffer) and remark is a string (comment).
1187 //
1188 AsmRemarks::AsmRemarks() : _remarks(new AsmRemarkCollection()) {
1189 assert(_remarks != nullptr, "Allocation failure!");
1190 }
1191
1192 AsmRemarks::~AsmRemarks() {
1193 assert(_remarks == nullptr, "Must 'clear()' before deleting!");
1194 }
1195
1196 const char* AsmRemarks::insert(uint offset, const char* remstr) {
1197 precond(remstr != nullptr);
1198 return _remarks->insert(offset, remstr);
1199 }
1200
1201 bool AsmRemarks::is_empty() const {
1202 return _remarks->is_empty();
1203 }
1204
1205 void AsmRemarks::share(const AsmRemarks &src) {
1206 precond(is_empty());
1207 clear();
1208 _remarks = src._remarks->reuse();
1209 }
1210
1211 void AsmRemarks::clear() {
1212 if (_remarks->clear() == 0) {
1213 delete _remarks;
1214 }
1215 _remarks = nullptr;
1216 }
1217
1218 uint AsmRemarks::print(uint offset, outputStream* strm) const {
1219 uint count = 0;
1220 const char* prefix = " ;; ";
1221 const char* remstr = _remarks->lookup(offset);
1222 while (remstr != nullptr) {
1223 strm->bol();
1224 strm->print("%s", prefix);
1225 // Don't interpret as format strings since it could contain '%'.
1226 strm->print_raw(remstr);
1227 // Advance to next line iff string didn't contain a cr() at the end.
1228 strm->bol();
1229 remstr = _remarks->next(offset);
1230 count++;
1231 }
1232 return count;
1233 }
1234
1235 // ----- DbgStrings ------------------------------------------------------------
1236 //
1237 // Acting as interface to reference counted collection of (debug) strings used
1238 // in the code generated, and thus requiring a fixed address.
1239 //
1240 DbgStrings::DbgStrings() : _strings(new DbgStringCollection()) {
1241 assert(_strings != nullptr, "Allocation failure!");
1242 }
1243
1244 DbgStrings::~DbgStrings() {
1245 assert(_strings == nullptr, "Must 'clear()' before deleting!");
1246 }
1247
1248 const char* DbgStrings::insert(const char* dbgstr) {
1249 const char* str = _strings->lookup(dbgstr);
1250 return str != nullptr ? str : _strings->insert(dbgstr);
1251 }
1252
1253 bool DbgStrings::is_empty() const {
1254 return _strings->is_empty();
1255 }
1256
1257 void DbgStrings::share(const DbgStrings &src) {
1258 precond(is_empty());
1259 clear();
1260 _strings = src._strings->reuse();
1261 }
1262
1263 void DbgStrings::clear() {
1264 if (_strings->clear() == 0) {
1265 delete _strings;
1266 }
1267 _strings = nullptr;
1268 }
1269
1270 // ----- AsmRemarkCollection ---------------------------------------------------
1271
1272 const char* AsmRemarkCollection::insert(uint offset, const char* remstr) {
1273 precond(remstr != nullptr);
1274 Cell* cell = new Cell { remstr, offset };
1275 if (is_empty()) {
1276 cell->prev = cell;
1277 cell->next = cell;
1278 _remarks = cell;
1279 } else {
1280 _remarks->push_back(cell);
1281 }
1282 return cell->string();
1283 }
1284
1285 const char* AsmRemarkCollection::lookup(uint offset) const {
1286 _next = _remarks;
1287 return next(offset);
1288 }
1289
1290 const char* AsmRemarkCollection::next(uint offset) const {
1291 if (_next != nullptr) {
1292 Cell* i = _next;
1293 do {
1294 if (i->offset == offset) {
1295 _next = i->next == _remarks ? nullptr : i->next;
1296 return i->string();
1297 }
1298 i = i->next;
1299 } while (i != _remarks);
1300 _next = nullptr;
1301 }
1302 return nullptr;
1303 }
1304
1305 uint AsmRemarkCollection::clear() {
1306 precond(_ref_cnt > 0);
1307 if (--_ref_cnt > 0) {
1308 return _ref_cnt;
1309 }
1310 if (!is_empty()) {
1311 uint count = 0;
1312 Cell* i = _remarks;
1313 do {
1314 Cell* next = i->next;
1315 delete i;
1316 i = next;
1317 count++;
1318 } while (i != _remarks);
1319
1320 log_debug(codestrings)("Clear %u asm-remark%s.", count, count == 1 ? "" : "s");
1321 _remarks = nullptr;
1322 }
1323 return 0; // i.e. _ref_cnt == 0
1324 }
1325
1326 // ----- DbgStringCollection ---------------------------------------------------
1327
1328 const char* DbgStringCollection::insert(const char* dbgstr) {
1329 precond(dbgstr != nullptr);
1330 Cell* cell = new Cell { dbgstr };
1331
1332 if (is_empty()) {
1333 cell->prev = cell;
1334 cell->next = cell;
1335 _strings = cell;
1336 } else {
1337 _strings->push_back(cell);
1338 }
1339 return cell->string();
1340 }
1341
1342 const char* DbgStringCollection::lookup(const char* dbgstr) const {
1343 precond(dbgstr != nullptr);
1344 if (_strings != nullptr) {
1345 Cell* i = _strings;
1346 do {
1347 if (strcmp(i->string(), dbgstr) == 0) {
1348 return i->string();
1349 }
1350 i = i->next;
1351 } while (i != _strings);
1352 }
1353 return nullptr;
1354 }
1355
1356 uint DbgStringCollection::clear() {
1357 precond(_ref_cnt > 0);
1358 if (--_ref_cnt > 0) {
1359 return _ref_cnt;
1360 }
1361 if (!is_empty()) {
1362 uint count = 0;
1363 Cell* i = _strings;
1364 do {
1365 Cell* next = i->next;
1366 delete i;
1367 i = next;
1368 count++;
1369 } while (i != _strings);
1370
1371 log_debug(codestrings)("Clear %u dbg-string%s.", count, count == 1 ? "" : "s");
1372 _strings = nullptr;
1373 }
1374 return 0; // i.e. _ref_cnt == 0
1375 }
1376
1377 #endif // not PRODUCT