1 /*
2 * Copyright (c) 1997, 2023, 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/methodCounters.hpp"
33 #include "oops/methodData.hpp"
34 #include "oops/oop.inline.hpp"
35 #include "runtime/icache.hpp"
36 #include "runtime/safepointVerifiers.hpp"
37 #include "utilities/align.hpp"
38 #include "utilities/copy.hpp"
39 #include "utilities/powerOfTwo.hpp"
40 #include "utilities/xmlstream.hpp"
41
42 // The structure of a CodeSection:
43 //
44 // _start -> +----------------+
45 // | machine code...|
46 // _end -> |----------------|
47 // | |
48 // | (empty) |
49 // | |
50 // | |
51 // +----------------+
52 // _limit -> | |
53 //
54 // _locs_start -> +----------------+
55 // |reloc records...|
56 // |----------------|
57 // _locs_end -> | |
58 // | |
59 // | (empty) |
60 // | |
61 // | |
62 // +----------------+
63 // _locs_limit -> | |
64 // The _end (resp. _limit) pointer refers to the first
65 // unused (resp. unallocated) byte.
66
67 // The structure of the CodeBuffer while code is being accumulated:
68 //
69 // _total_start -> \
70 // _consts._start -> +----------------+
71 // | |
72 // | Constants |
73 // | |
74 // _insts._start -> |----------------|
75 // | |
76 // | Code |
77 // | |
78 // _stubs._start -> |----------------|
79 // | |
80 // | Stubs | (also handlers for deopt/exception)
81 // | |
82 // +----------------+
83 // + _total_size -> | |
84 //
85 // When the code and relocations are copied to the code cache,
86 // the empty parts of each section are removed, and everything
87 // is copied into contiguous locations.
88
89 typedef CodeBuffer::csize_t csize_t; // file-local definition
90
91 // External buffer, in a predefined CodeBlob.
92 // Important: The code_start must be taken exactly, and not realigned.
93 CodeBuffer::CodeBuffer(CodeBlob* blob) DEBUG_ONLY(: Scrubber(this, sizeof(*this))) {
94 // Provide code buffer with meaningful name
95 initialize_misc(blob->name());
96 initialize(blob->content_begin(), blob->content_size());
97 debug_only(verify_section_allocation();)
98 }
99
100 void CodeBuffer::initialize(csize_t code_size, csize_t locs_size) {
101 // Always allow for empty slop around each section.
102 int slop = (int) CodeSection::end_slop();
103
104 assert(SECT_LIMIT == 3, "total_size explicitly lists all section alignments");
105 int total_size = code_size + _consts.alignment() + _insts.alignment() + _stubs.alignment() + SECT_LIMIT * slop;
106
107 assert(blob() == nullptr, "only once");
108 set_blob(BufferBlob::create(_name, total_size));
109 if (blob() == nullptr) {
110 // The assembler constructor will throw a fatal on an empty CodeBuffer.
111 return; // caller must test this
112 }
113
114 // Set up various pointers into the blob.
115 initialize(_total_start, _total_size);
116
117 assert((uintptr_t)insts_begin() % CodeEntryAlignment == 0, "instruction start not code entry aligned");
118
119 pd_initialize();
120
121 if (locs_size != 0) {
122 _insts.initialize_locs(locs_size / sizeof(relocInfo));
123 }
124
125 debug_only(verify_section_allocation();)
126 }
127
128
129 CodeBuffer::~CodeBuffer() {
130 verify_section_allocation();
131
132 // If we allocated our code buffer from the CodeCache via a BufferBlob, and
133 // it's not permanent, then free the BufferBlob. The rest of the memory
134 // will be freed when the ResourceObj is released.
135 for (CodeBuffer* cb = this; cb != nullptr; cb = cb->before_expand()) {
136 // Previous incarnations of this buffer are held live, so that internal
137 // addresses constructed before expansions will not be confused.
138 cb->free_blob();
139 // free any overflow storage
140 delete cb->_overflow_arena;
141 }
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->has_locs()) 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_methodCounters()) {
541 m = ((MethodCounters*)m)->method();
542 }
543 if (m->is_method()) {
544 m = ((Method*)m)->method_holder();
545 }
546 if (m->is_klass()) {
547 append_oop_references(&oops, (Klass*)m);
548 } else {
549 // XXX This will currently occur for MDO which don't
550 // have a backpointer. This has to be fixed later.
551 m->print();
552 ShouldNotReachHere();
553 }
554 }
555 }
556 }
557 }
558 }
559
560 if (!oop_recorder()->is_unused()) {
561 for (int i = 0; i < oop_recorder()->metadata_count(); i++) {
562 Metadata* m = oop_recorder()->metadata_at(i);
563 if (oop_recorder()->is_real(m)) {
564 if (m->is_methodData()) {
565 m = ((MethodData*)m)->method();
566 }
567 if (m->is_methodCounters()) {
568 m = ((MethodCounters*)m)->method();
569 }
570 if (m->is_method()) {
571 m = ((Method*)m)->method_holder();
572 }
573 if (m->is_klass()) {
574 append_oop_references(&oops, (Klass*)m);
575 } else {
576 m->print();
577 ShouldNotReachHere();
578 }
579 }
580 }
581
582 }
583
584 // Add the class loader of Method* for the nmethod itself
585 append_oop_references(&oops, mh->method_holder());
586
587 // Add any oops that we've found
588 Thread* thread = Thread::current();
589 for (int i = 0; i < oops.length(); i++) {
590 oop_recorder()->find_index((jobject)thread->handle_area()->allocate_handle(oops.at(i)));
591 }
592 }
593
594
595
596 csize_t CodeBuffer::total_offset_of(const CodeSection* cs) const {
597 csize_t size_so_far = 0;
598 for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) {
599 const CodeSection* cur_cs = code_section(n);
600 if (!cur_cs->is_empty()) {
601 size_so_far = cur_cs->align_at_start(size_so_far);
602 }
603 if (cur_cs->index() == cs->index()) {
604 return size_so_far;
605 }
606 size_so_far += cur_cs->size();
607 }
608 ShouldNotReachHere();
609 return -1;
610 }
611
612 int CodeBuffer::total_skipped_instructions_size() const {
613 int total_skipped_size = 0;
614 for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) {
615 const CodeSection* cur_cs = code_section(n);
616 if (!cur_cs->is_empty()) {
617 total_skipped_size += cur_cs->_skipped_instructions_size;
618 }
619 }
620 return total_skipped_size;
621 }
622
623 csize_t CodeBuffer::total_relocation_size() const {
624 csize_t total = copy_relocations_to(nullptr); // dry run only
625 return (csize_t) align_up(total, HeapWordSize);
626 }
627
628 csize_t CodeBuffer::copy_relocations_to(address buf, csize_t buf_limit, bool only_inst) const {
629 csize_t buf_offset = 0;
630 csize_t code_end_so_far = 0;
631 csize_t code_point_so_far = 0;
632
633 assert((uintptr_t)buf % HeapWordSize == 0, "buf must be fully aligned");
634 assert(buf_limit % HeapWordSize == 0, "buf must be evenly sized");
635
636 for (int n = (int) SECT_FIRST; n < (int)SECT_LIMIT; n++) {
637 if (only_inst && (n != (int)SECT_INSTS)) {
638 // Need only relocation info for code.
639 continue;
640 }
641 // pull relocs out of each section
642 const CodeSection* cs = code_section(n);
643 assert(!(cs->is_empty() && cs->locs_count() > 0), "sanity");
644 if (cs->is_empty()) continue; // skip trivial section
645 relocInfo* lstart = cs->locs_start();
646 relocInfo* lend = cs->locs_end();
647 csize_t lsize = (csize_t)( (address)lend - (address)lstart );
648 csize_t csize = cs->size();
649 code_end_so_far = cs->align_at_start(code_end_so_far);
650
651 if (lsize > 0) {
652 // Figure out how to advance the combined relocation point
653 // first to the beginning of this section.
654 // We'll insert one or more filler relocs to span that gap.
655 // (Don't bother to improve this by editing the first reloc's offset.)
656 csize_t new_code_point = code_end_so_far;
657 for (csize_t jump;
658 code_point_so_far < new_code_point;
659 code_point_so_far += jump) {
660 jump = new_code_point - code_point_so_far;
661 relocInfo filler = relocInfo::filler_info();
662 if (jump >= filler.addr_offset()) {
663 jump = filler.addr_offset();
664 } else { // else shrink the filler to fit
665 filler = relocInfo(relocInfo::none, jump);
666 }
667 if (buf != nullptr) {
668 assert(buf_offset + (csize_t)sizeof(filler) <= buf_limit, "filler in bounds");
669 *(relocInfo*)(buf+buf_offset) = filler;
670 }
671 buf_offset += sizeof(filler);
672 }
673
674 // Update code point and end to skip past this section:
675 csize_t last_code_point = code_end_so_far + cs->locs_point_off();
676 assert(code_point_so_far <= last_code_point, "sanity");
677 code_point_so_far = last_code_point; // advance past this guy's relocs
678 }
679 code_end_so_far += csize; // advance past this guy's instructions too
680
681 // Done with filler; emit the real relocations:
682 if (buf != nullptr && lsize != 0) {
683 assert(buf_offset + lsize <= buf_limit, "target in bounds");
684 assert((uintptr_t)lstart % HeapWordSize == 0, "sane start");
685 if (buf_offset % HeapWordSize == 0) {
686 // Use wordwise copies if possible:
687 Copy::disjoint_words((HeapWord*)lstart,
688 (HeapWord*)(buf+buf_offset),
689 (lsize + HeapWordSize-1) / HeapWordSize);
690 } else {
691 Copy::conjoint_jbytes(lstart, buf+buf_offset, lsize);
692 }
693 }
694 buf_offset += lsize;
695 }
696
697 // Align end of relocation info in target.
698 while (buf_offset % HeapWordSize != 0) {
699 if (buf != nullptr) {
700 relocInfo padding = relocInfo(relocInfo::none, 0);
701 assert(buf_offset + (csize_t)sizeof(padding) <= buf_limit, "padding in bounds");
702 *(relocInfo*)(buf+buf_offset) = padding;
703 }
704 buf_offset += sizeof(relocInfo);
705 }
706
707 assert(only_inst || code_end_so_far == total_content_size(), "sanity");
708
709 return buf_offset;
710 }
711
712 csize_t CodeBuffer::copy_relocations_to(CodeBlob* dest) const {
713 address buf = nullptr;
714 csize_t buf_offset = 0;
715 csize_t buf_limit = 0;
716
717 if (dest != nullptr) {
718 buf = (address)dest->relocation_begin();
719 buf_limit = (address)dest->relocation_end() - buf;
720 }
721 // if dest is null, this is just the sizing pass
722 //
723 buf_offset = copy_relocations_to(buf, buf_limit, false);
724
725 return buf_offset;
726 }
727
728 void CodeBuffer::copy_code_to(CodeBlob* dest_blob) {
729 #ifndef PRODUCT
730 if (PrintNMethods && (WizardMode || Verbose)) {
731 tty->print("done with CodeBuffer:");
732 ((CodeBuffer*)this)->print_on(tty);
733 }
734 #endif //PRODUCT
735
736 CodeBuffer dest(dest_blob);
737 assert(dest_blob->content_size() >= total_content_size(), "good sizing");
738 this->compute_final_layout(&dest);
739
740 // Set beginning of constant table before relocating.
741 dest_blob->set_ctable_begin(dest.consts()->start());
742
743 relocate_code_to(&dest);
744
745 // Share assembly remarks and debug strings with the blob.
746 NOT_PRODUCT(dest_blob->use_remarks(_asm_remarks));
747 NOT_PRODUCT(dest_blob->use_strings(_dbg_strings));
748
749 // Done moving code bytes; were they the right size?
750 assert((int)align_up(dest.total_content_size(), oopSize) == dest_blob->content_size(), "sanity");
751
752 // Flush generated code
753 ICache::invalidate_range(dest_blob->code_begin(), dest_blob->code_size());
754 }
755
756 // Move all my code into another code buffer. Consult applicable
757 // relocs to repair embedded addresses. The layout in the destination
758 // CodeBuffer is different to the source CodeBuffer: the destination
759 // CodeBuffer gets the final layout (consts, insts, stubs in order of
760 // ascending address).
761 void CodeBuffer::relocate_code_to(CodeBuffer* dest) const {
762 address dest_end = dest->_total_start + dest->_total_size;
763 address dest_filled = nullptr;
764 for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) {
765 // pull code out of each section
766 const CodeSection* cs = code_section(n);
767 if (cs->is_empty()) continue; // skip trivial section
768 CodeSection* dest_cs = dest->code_section(n);
769 assert(cs->size() == dest_cs->size(), "sanity");
770 csize_t usize = dest_cs->size();
771 csize_t wsize = align_up(usize, HeapWordSize);
772 assert(dest_cs->start() + wsize <= dest_end, "no overflow");
773 // Copy the code as aligned machine words.
774 // This may also include an uninitialized partial word at the end.
775 Copy::disjoint_words((HeapWord*)cs->start(),
776 (HeapWord*)dest_cs->start(),
777 wsize / HeapWordSize);
778
779 if (dest->blob() == nullptr) {
780 // Destination is a final resting place, not just another buffer.
781 // Normalize uninitialized bytes in the final padding.
782 Copy::fill_to_bytes(dest_cs->end(), dest_cs->remaining(),
783 Assembler::code_fill_byte());
784 }
785 // Keep track of the highest filled address
786 dest_filled = MAX2(dest_filled, dest_cs->end() + dest_cs->remaining());
787
788 assert(cs->locs_start() != (relocInfo*)badAddress,
789 "this section carries no reloc storage, but reloc was attempted");
790
791 // Make the new code copy use the old copy's relocations:
792 dest_cs->initialize_locs_from(cs);
793 }
794
795 // Do relocation after all sections are copied.
796 // This is necessary if the code uses constants in stubs, which are
797 // relocated when the corresponding instruction in the code (e.g., a
798 // call) is relocated. Stubs are placed behind the main code
799 // section, so that section has to be copied before relocating.
800 for (int n = (int) SECT_FIRST; n < (int)SECT_LIMIT; n++) {
801 // pull code out of each section
802 const CodeSection* cs = code_section(n);
803 if (cs->is_empty() || !cs->has_locs()) continue; // skip trivial section
804 CodeSection* dest_cs = dest->code_section(n);
805 { // Repair the pc relative information in the code after the move
806 RelocIterator iter(dest_cs);
807 while (iter.next()) {
808 iter.reloc()->fix_relocation_after_move(this, dest);
809 }
810 }
811 }
812
813 if (dest->blob() == nullptr && dest_filled != nullptr) {
814 // Destination is a final resting place, not just another buffer.
815 // Normalize uninitialized bytes in the final padding.
816 Copy::fill_to_bytes(dest_filled, dest_end - dest_filled,
817 Assembler::code_fill_byte());
818
819 }
820 }
821
822 csize_t CodeBuffer::figure_expanded_capacities(CodeSection* which_cs,
823 csize_t amount,
824 csize_t* new_capacity) {
825 csize_t new_total_cap = 0;
826
827 for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) {
828 const CodeSection* sect = code_section(n);
829
830 if (!sect->is_empty()) {
831 // Compute initial padding; assign it to the previous section,
832 // even if it's empty (e.g. consts section can be empty).
833 // Cf. compute_final_layout
834 csize_t padding = sect->align_at_start(new_total_cap) - new_total_cap;
835 if (padding != 0) {
836 new_total_cap += padding;
837 assert(n - 1 >= SECT_FIRST, "sanity");
838 new_capacity[n - 1] += padding;
839 }
840 }
841
842 csize_t exp = sect->size(); // 100% increase
843 if ((uint)exp < 4*K) exp = 4*K; // minimum initial increase
844 if (sect == which_cs) {
845 if (exp < amount) exp = amount;
846 if (StressCodeBuffers) exp = amount; // expand only slightly
847 } else if (n == SECT_INSTS) {
848 // scale down inst increases to a more modest 25%
849 exp = 4*K + ((exp - 4*K) >> 2);
850 if (StressCodeBuffers) exp = amount / 2; // expand only slightly
851 } else if (sect->is_empty()) {
852 // do not grow an empty secondary section
853 exp = 0;
854 }
855 // Allow for inter-section slop:
856 exp += CodeSection::end_slop();
857 csize_t new_cap = sect->size() + exp;
858 if (new_cap < sect->capacity()) {
859 // No need to expand after all.
860 new_cap = sect->capacity();
861 }
862 new_capacity[n] = new_cap;
863 new_total_cap += new_cap;
864 }
865
866 return new_total_cap;
867 }
868
869 void CodeBuffer::expand(CodeSection* which_cs, csize_t amount) {
870 #ifndef PRODUCT
871 if (PrintNMethods && (WizardMode || Verbose)) {
872 tty->print("expanding CodeBuffer:");
873 this->print_on(tty);
874 }
875
876 if (StressCodeBuffers && blob() != nullptr) {
877 static int expand_count = 0;
878 if (expand_count >= 0) expand_count += 1;
879 if (expand_count > 100 && is_power_of_2(expand_count)) {
880 tty->print_cr("StressCodeBuffers: have expanded %d times", expand_count);
881 // simulate an occasional allocation failure:
882 free_blob();
883 }
884 }
885 #endif //PRODUCT
886
887 // Resizing must be allowed
888 {
889 if (blob() == nullptr) return; // caller must check if blob is null
890 }
891
892 // Figure new capacity for each section.
893 csize_t new_capacity[SECT_LIMIT];
894 memset(new_capacity, 0, sizeof(csize_t) * SECT_LIMIT);
895 csize_t new_total_cap
896 = figure_expanded_capacities(which_cs, amount, new_capacity);
897
898 // Create a new (temporary) code buffer to hold all the new data
899 CodeBuffer cb(name(), new_total_cap, 0);
900 if (cb.blob() == nullptr) {
901 // Failed to allocate in code cache.
902 free_blob();
903 return;
904 }
905
906 // Create an old code buffer to remember which addresses used to go where.
907 // This will be useful when we do final assembly into the code cache,
908 // because we will need to know how to warp any internal address that
909 // has been created at any time in this CodeBuffer's past.
910 CodeBuffer* bxp = new CodeBuffer(_total_start, _total_size);
911 bxp->take_over_code_from(this); // remember the old undersized blob
912 DEBUG_ONLY(this->_blob = nullptr); // silence a later assert
913 bxp->_before_expand = this->_before_expand;
914 this->_before_expand = bxp;
915
916 // Give each section its required (expanded) capacity.
917 for (int n = (int)SECT_LIMIT-1; n >= SECT_FIRST; n--) {
918 CodeSection* cb_sect = cb.code_section(n);
919 CodeSection* this_sect = code_section(n);
920 if (new_capacity[n] == 0) continue; // already nulled out
921 if (n != SECT_INSTS) {
922 cb.initialize_section_size(cb_sect, new_capacity[n]);
923 }
924 assert(cb_sect->capacity() >= new_capacity[n], "big enough");
925 address cb_start = cb_sect->start();
926 cb_sect->set_end(cb_start + this_sect->size());
927 if (this_sect->mark() == nullptr) {
928 cb_sect->clear_mark();
929 } else {
930 cb_sect->set_mark(cb_start + this_sect->mark_off());
931 }
932 }
933
934 // Needs to be initialized when calling fix_relocation_after_move.
935 cb.blob()->set_ctable_begin(cb.consts()->start());
936
937 // Move all the code and relocations to the new blob:
938 relocate_code_to(&cb);
939
940 // Copy the temporary code buffer into the current code buffer.
941 // Basically, do {*this = cb}, except for some control information.
942 this->take_over_code_from(&cb);
943 cb.set_blob(nullptr);
944
945 // Zap the old code buffer contents, to avoid mistakenly using them.
946 debug_only(Copy::fill_to_bytes(bxp->_total_start, bxp->_total_size,
947 badCodeHeapFreeVal);)
948
949 // Make certain that the new sections are all snugly inside the new blob.
950 debug_only(verify_section_allocation();)
951
952 #ifndef PRODUCT
953 _decode_begin = nullptr; // sanity
954 if (PrintNMethods && (WizardMode || Verbose)) {
955 tty->print("expanded CodeBuffer:");
956 this->print_on(tty);
957 }
958 #endif //PRODUCT
959 }
960
961 void CodeBuffer::take_over_code_from(CodeBuffer* cb) {
962 // Must already have disposed of the old blob somehow.
963 assert(blob() == nullptr, "must be empty");
964 // Take the new blob away from cb.
965 set_blob(cb->blob());
966 // Take over all the section pointers.
967 for (int n = 0; n < (int)SECT_LIMIT; n++) {
968 CodeSection* cb_sect = cb->code_section(n);
969 CodeSection* this_sect = code_section(n);
970 this_sect->take_over_code_from(cb_sect);
971 }
972 _overflow_arena = cb->_overflow_arena;
973 cb->_overflow_arena = nullptr;
974 // Make sure the old cb won't try to use it or free it.
975 DEBUG_ONLY(cb->_blob = (BufferBlob*)badAddress);
976 }
977
978 void CodeBuffer::verify_section_allocation() {
979 address tstart = _total_start;
980 if (tstart == badAddress) return; // smashed by set_blob(nullptr)
981 address tend = tstart + _total_size;
982 if (_blob != nullptr) {
983 guarantee(tstart >= _blob->content_begin(), "sanity");
984 guarantee(tend <= _blob->content_end(), "sanity");
985 }
986 // Verify disjointness.
987 for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) {
988 CodeSection* sect = code_section(n);
989 if (!sect->is_allocated() || sect->is_empty()) {
990 continue;
991 }
992 guarantee(_blob == nullptr || is_aligned(sect->start(), sect->alignment()),
993 "start is aligned");
994 for (int m = n + 1; m < (int) SECT_LIMIT; m++) {
995 CodeSection* other = code_section(m);
996 if (!other->is_allocated() || other == sect) {
997 continue;
998 }
999 guarantee(other->disjoint(sect), "sanity");
1000 }
1001 guarantee(sect->end() <= tend, "sanity, sect_end: " PTR_FORMAT " tend: " PTR_FORMAT " size: %d", p2i(sect->end()), p2i(tend), (int)_total_size);
1002 guarantee(sect->end() <= sect->limit(), "sanity, sect_end: " PTR_FORMAT " sect_limit: " PTR_FORMAT, p2i(sect->end()), p2i(sect->limit()));
1003 }
1004 }
1005
1006 void CodeBuffer::log_section_sizes(const char* name) {
1007 if (xtty != nullptr) {
1008 ttyLocker ttyl;
1009 // log info about buffer usage
1010 xtty->head("blob name='%s' total_size='%d'", name, _total_size);
1011 for (int n = (int) CodeBuffer::SECT_FIRST; n < (int) CodeBuffer::SECT_LIMIT; n++) {
1012 CodeSection* sect = code_section(n);
1013 if (!sect->is_allocated() || sect->is_empty()) continue;
1014 xtty->elem("sect index='%d' capacity='%d' size='%d' remaining='%d'",
1015 n, sect->capacity(), sect->size(), sect->remaining());
1016 }
1017 xtty->tail("blob");
1018 }
1019 }
1020
1021 bool CodeBuffer::finalize_stubs() {
1022 // Record size of code before we generate stubs in instructions section
1023 _main_code_size = _insts.size();
1024 if (_finalize_stubs && !pd_finalize_stubs()) {
1025 // stub allocation failure
1026 return false;
1027 }
1028 _finalize_stubs = false;
1029 return true;
1030 }
1031
1032 void CodeBuffer::shared_stub_to_interp_for(ciMethod* callee, csize_t call_offset) {
1033 if (_shared_stub_to_interp_requests == nullptr) {
1034 _shared_stub_to_interp_requests = new SharedStubToInterpRequests(8);
1035 }
1036 SharedStubToInterpRequest request(callee, call_offset);
1037 _shared_stub_to_interp_requests->push(request);
1038 _finalize_stubs = true;
1039 }
1040
1041 #ifndef PRODUCT
1042 void CodeBuffer::block_comment(ptrdiff_t offset, const char* comment) {
1043 if (_collect_comments) {
1044 const char* str = _asm_remarks.insert(offset, comment);
1045 postcond(str != comment);
1046 }
1047 }
1048
1049 const char* CodeBuffer::code_string(const char* str) {
1050 const char* tmp = _dbg_strings.insert(str);
1051 postcond(tmp != str);
1052 return tmp;
1053 }
1054
1055 void CodeBuffer::decode() {
1056 ttyLocker ttyl;
1057 Disassembler::decode(decode_begin(), insts_end(), tty NOT_PRODUCT(COMMA &asm_remarks()));
1058 _decode_begin = insts_end();
1059 }
1060
1061 void CodeSection::print_on(outputStream* st, const char* name) {
1062 csize_t locs_size = locs_end() - locs_start();
1063 st->print_cr(" %7s.code = " PTR_FORMAT " : " PTR_FORMAT " : " PTR_FORMAT " (%d of %d)",
1064 name, p2i(start()), p2i(end()), p2i(limit()), size(), capacity());
1065 st->print_cr(" %7s.locs = " PTR_FORMAT " : " PTR_FORMAT " : " PTR_FORMAT " (%d of %d) point=%d",
1066 name, p2i(locs_start()), p2i(locs_end()), p2i(locs_limit()), locs_size, locs_capacity(), locs_point_off());
1067 if (PrintRelocations) {
1068 RelocIterator iter(this);
1069 iter.print_on(st);
1070 }
1071 }
1072
1073 void CodeBuffer::print_on(outputStream* st) {
1074 #if 0
1075 if (this == nullptr) { // gcc complains 'nonnull' argument 'this' compared to NULL
1076 st->print_cr("null CodeBuffer pointer");
1077 return;
1078 }
1079 #endif
1080
1081 st->print_cr("CodeBuffer:%s", name());
1082 for (int n = 0; n < (int)SECT_LIMIT; n++) {
1083 // print each section
1084 CodeSection* cs = code_section(n);
1085 cs->print_on(st, code_section_name(n));
1086 }
1087 }
1088
1089 // ----- CHeapString -----------------------------------------------------------
1090
1091 class CHeapString : public CHeapObj<mtCode> {
1092 public:
1093 CHeapString(const char* str) : _string(os::strdup(str)) {}
1094 ~CHeapString() {
1095 os::free((void*)_string);
1096 _string = nullptr;
1097 }
1098 const char* string() const { return _string; }
1099
1100 private:
1101 const char* _string;
1102 };
1103
1104 // ----- AsmRemarkCollection ---------------------------------------------------
1105
1106 class AsmRemarkCollection : public CHeapObj<mtCode> {
1107 public:
1108 AsmRemarkCollection() : _ref_cnt(1), _remarks(nullptr), _next(nullptr) {}
1109 ~AsmRemarkCollection() {
1110 assert(is_empty(), "Must 'clear()' before deleting!");
1111 assert(_ref_cnt == 0, "No uses must remain when deleting!");
1112 }
1113 AsmRemarkCollection* reuse() {
1114 precond(_ref_cnt > 0);
1115 return _ref_cnt++, this;
1116 }
1117
1118 const char* insert(uint offset, const char* remark);
1119 const char* lookup(uint offset) const;
1120 const char* next(uint offset) const;
1121
1122 bool is_empty() const { return _remarks == nullptr; }
1123 uint clear();
1124
1125 private:
1126 struct Cell : CHeapString {
1127 Cell(const char* remark, uint offset) :
1128 CHeapString(remark), offset(offset), prev(nullptr), next(nullptr) {}
1129 void push_back(Cell* cell) {
1130 Cell* head = this;
1131 Cell* tail = prev;
1132 tail->next = cell;
1133 cell->next = head;
1134 cell->prev = tail;
1135 prev = cell;
1136 }
1137 uint offset;
1138 Cell* prev;
1139 Cell* next;
1140 };
1141 uint _ref_cnt;
1142 Cell* _remarks;
1143 // Using a 'mutable' iteration pointer to allow 'const' on lookup/next (that
1144 // does not change the state of the list per se), supportig a simplistic
1145 // iteration scheme.
1146 mutable Cell* _next;
1147 };
1148
1149 // ----- DbgStringCollection ---------------------------------------------------
1150
1151 class DbgStringCollection : public CHeapObj<mtCode> {
1152 public:
1153 DbgStringCollection() : _ref_cnt(1), _strings(nullptr) {}
1154 ~DbgStringCollection() {
1155 assert(is_empty(), "Must 'clear()' before deleting!");
1156 assert(_ref_cnt == 0, "No uses must remain when deleting!");
1157 }
1158 DbgStringCollection* reuse() {
1159 precond(_ref_cnt > 0);
1160 return _ref_cnt++, this;
1161 }
1162
1163 const char* insert(const char* str);
1164 const char* lookup(const char* str) const;
1165
1166 bool is_empty() const { return _strings == nullptr; }
1167 uint clear();
1168
1169 private:
1170 struct Cell : CHeapString {
1171 Cell(const char* dbgstr) :
1172 CHeapString(dbgstr), prev(nullptr), next(nullptr) {}
1173 void push_back(Cell* cell) {
1174 Cell* head = this;
1175 Cell* tail = prev;
1176 tail->next = cell;
1177 cell->next = head;
1178 cell->prev = tail;
1179 prev = cell;
1180 }
1181 Cell* prev;
1182 Cell* next;
1183 };
1184 uint _ref_cnt;
1185 Cell* _strings;
1186 };
1187
1188 // ----- AsmRemarks ------------------------------------------------------------
1189 //
1190 // Acting as interface to reference counted mapping [offset -> remark], where
1191 // offset is a byte offset into an instruction stream (CodeBuffer, CodeBlob or
1192 // other memory buffer) and remark is a string (comment).
1193 //
1194 AsmRemarks::AsmRemarks() : _remarks(new AsmRemarkCollection()) {
1195 assert(_remarks != nullptr, "Allocation failure!");
1196 }
1197
1198 AsmRemarks::~AsmRemarks() {
1199 assert(_remarks == nullptr, "Must 'clear()' before deleting!");
1200 }
1201
1202 const char* AsmRemarks::insert(uint offset, const char* remstr) {
1203 precond(remstr != nullptr);
1204 return _remarks->insert(offset, remstr);
1205 }
1206
1207 bool AsmRemarks::is_empty() const {
1208 return _remarks->is_empty();
1209 }
1210
1211 void AsmRemarks::share(const AsmRemarks &src) {
1212 precond(is_empty());
1213 clear();
1214 _remarks = src._remarks->reuse();
1215 }
1216
1217 void AsmRemarks::clear() {
1218 if (_remarks->clear() == 0) {
1219 delete _remarks;
1220 }
1221 _remarks = nullptr;
1222 }
1223
1224 uint AsmRemarks::print(uint offset, outputStream* strm) const {
1225 uint count = 0;
1226 const char* prefix = " ;; ";
1227 const char* remstr = _remarks->lookup(offset);
1228 while (remstr != nullptr) {
1229 strm->bol();
1230 strm->print("%s", prefix);
1231 // Don't interpret as format strings since it could contain '%'.
1232 strm->print_raw(remstr);
1233 // Advance to next line iff string didn't contain a cr() at the end.
1234 strm->bol();
1235 remstr = _remarks->next(offset);
1236 count++;
1237 }
1238 return count;
1239 }
1240
1241 // ----- DbgStrings ------------------------------------------------------------
1242 //
1243 // Acting as interface to reference counted collection of (debug) strings used
1244 // in the code generated, and thus requiring a fixed address.
1245 //
1246 DbgStrings::DbgStrings() : _strings(new DbgStringCollection()) {
1247 assert(_strings != nullptr, "Allocation failure!");
1248 }
1249
1250 DbgStrings::~DbgStrings() {
1251 assert(_strings == nullptr, "Must 'clear()' before deleting!");
1252 }
1253
1254 const char* DbgStrings::insert(const char* dbgstr) {
1255 const char* str = _strings->lookup(dbgstr);
1256 return str != nullptr ? str : _strings->insert(dbgstr);
1257 }
1258
1259 bool DbgStrings::is_empty() const {
1260 return _strings->is_empty();
1261 }
1262
1263 void DbgStrings::share(const DbgStrings &src) {
1264 precond(is_empty());
1265 clear();
1266 _strings = src._strings->reuse();
1267 }
1268
1269 void DbgStrings::clear() {
1270 if (_strings->clear() == 0) {
1271 delete _strings;
1272 }
1273 _strings = nullptr;
1274 }
1275
1276 // ----- AsmRemarkCollection ---------------------------------------------------
1277
1278 const char* AsmRemarkCollection::insert(uint offset, const char* remstr) {
1279 precond(remstr != nullptr);
1280 Cell* cell = new Cell { remstr, offset };
1281 if (is_empty()) {
1282 cell->prev = cell;
1283 cell->next = cell;
1284 _remarks = cell;
1285 } else {
1286 _remarks->push_back(cell);
1287 }
1288 return cell->string();
1289 }
1290
1291 const char* AsmRemarkCollection::lookup(uint offset) const {
1292 _next = _remarks;
1293 return next(offset);
1294 }
1295
1296 const char* AsmRemarkCollection::next(uint offset) const {
1297 if (_next != nullptr) {
1298 Cell* i = _next;
1299 do {
1300 if (i->offset == offset) {
1301 _next = i->next == _remarks ? nullptr : i->next;
1302 return i->string();
1303 }
1304 i = i->next;
1305 } while (i != _remarks);
1306 _next = nullptr;
1307 }
1308 return nullptr;
1309 }
1310
1311 uint AsmRemarkCollection::clear() {
1312 precond(_ref_cnt > 0);
1313 if (--_ref_cnt > 0) {
1314 return _ref_cnt;
1315 }
1316 if (!is_empty()) {
1317 uint count = 0;
1318 Cell* i = _remarks;
1319 do {
1320 Cell* next = i->next;
1321 delete i;
1322 i = next;
1323 count++;
1324 } while (i != _remarks);
1325
1326 log_debug(codestrings)("Clear %u asm-remark%s.", count, count == 1 ? "" : "s");
1327 _remarks = nullptr;
1328 }
1329 return 0; // i.e. _ref_cnt == 0
1330 }
1331
1332 // ----- DbgStringCollection ---------------------------------------------------
1333
1334 const char* DbgStringCollection::insert(const char* dbgstr) {
1335 precond(dbgstr != nullptr);
1336 Cell* cell = new Cell { dbgstr };
1337
1338 if (is_empty()) {
1339 cell->prev = cell;
1340 cell->next = cell;
1341 _strings = cell;
1342 } else {
1343 _strings->push_back(cell);
1344 }
1345 return cell->string();
1346 }
1347
1348 const char* DbgStringCollection::lookup(const char* dbgstr) const {
1349 precond(dbgstr != nullptr);
1350 if (_strings != nullptr) {
1351 Cell* i = _strings;
1352 do {
1353 if (strcmp(i->string(), dbgstr) == 0) {
1354 return i->string();
1355 }
1356 i = i->next;
1357 } while (i != _strings);
1358 }
1359 return nullptr;
1360 }
1361
1362 uint DbgStringCollection::clear() {
1363 precond(_ref_cnt > 0);
1364 if (--_ref_cnt > 0) {
1365 return _ref_cnt;
1366 }
1367 if (!is_empty()) {
1368 uint count = 0;
1369 Cell* i = _strings;
1370 do {
1371 Cell* next = i->next;
1372 delete i;
1373 i = next;
1374 count++;
1375 } while (i != _strings);
1376
1377 log_debug(codestrings)("Clear %u dbg-string%s.", count, count == 1 ? "" : "s");
1378 _strings = nullptr;
1379 }
1380 return 0; // i.e. _ref_cnt == 0
1381 }
1382
1383 #endif // not PRODUCT