Line data Source code
1 : // Copyright 2010 the V8 project authors. All rights reserved.
2 : // Use of this source code is governed by a BSD-style license that can be
3 : // found in the LICENSE file.
4 :
5 : #include "src/gdb-jit.h"
6 :
7 : #include <memory>
8 : #include <vector>
9 :
10 : #include "src/api.h"
11 : #include "src/base/bits.h"
12 : #include "src/base/platform/platform.h"
13 : #include "src/bootstrapper.h"
14 : #include "src/frames-inl.h"
15 : #include "src/frames.h"
16 : #include "src/global-handles.h"
17 : #include "src/messages.h"
18 : #include "src/objects.h"
19 : #include "src/ostreams.h"
20 : #include "src/snapshot/natives.h"
21 : #include "src/splay-tree-inl.h"
22 :
23 : namespace v8 {
24 : namespace internal {
25 : namespace GDBJITInterface {
26 :
27 : #ifdef ENABLE_GDB_JIT_INTERFACE
28 :
29 : #ifdef __APPLE__
30 : #define __MACH_O
31 : class MachO;
32 : class MachOSection;
33 : typedef MachO DebugObject;
34 : typedef MachOSection DebugSection;
35 : #else
36 : #define __ELF
37 : class ELF;
38 : class ELFSection;
39 : typedef ELF DebugObject;
40 : typedef ELFSection DebugSection;
41 : #endif
42 :
43 : class Writer BASE_EMBEDDED {
44 : public:
45 : explicit Writer(DebugObject* debug_object)
46 : : debug_object_(debug_object),
47 : position_(0),
48 : capacity_(1024),
49 0 : buffer_(reinterpret_cast<byte*>(malloc(capacity_))) {
50 : }
51 :
52 : ~Writer() {
53 0 : free(buffer_);
54 : }
55 :
56 : uintptr_t position() const {
57 : return position_;
58 : }
59 :
60 : template<typename T>
61 : class Slot {
62 : public:
63 : Slot(Writer* w, uintptr_t offset) : w_(w), offset_(offset) { }
64 :
65 : T* operator-> () {
66 0 : return w_->RawSlotAt<T>(offset_);
67 : }
68 :
69 : void set(const T& value) {
70 0 : *w_->RawSlotAt<T>(offset_) = value;
71 : }
72 :
73 : Slot<T> at(int i) {
74 0 : return Slot<T>(w_, offset_ + sizeof(T) * i);
75 : }
76 :
77 : private:
78 : Writer* w_;
79 : uintptr_t offset_;
80 : };
81 :
82 : template<typename T>
83 0 : void Write(const T& val) {
84 0 : Ensure(position_ + sizeof(T));
85 0 : *RawSlotAt<T>(position_) = val;
86 0 : position_ += sizeof(T);
87 0 : }
88 :
89 : template<typename T>
90 : Slot<T> SlotAt(uintptr_t offset) {
91 0 : Ensure(offset + sizeof(T));
92 : return Slot<T>(this, offset);
93 : }
94 :
95 : template<typename T>
96 : Slot<T> CreateSlotHere() {
97 0 : return CreateSlotsHere<T>(1);
98 : }
99 :
100 : template<typename T>
101 0 : Slot<T> CreateSlotsHere(uint32_t count) {
102 0 : uintptr_t slot_position = position_;
103 0 : position_ += sizeof(T) * count;
104 0 : Ensure(position_);
105 0 : return SlotAt<T>(slot_position);
106 : }
107 :
108 0 : void Ensure(uintptr_t pos) {
109 0 : if (capacity_ < pos) {
110 0 : while (capacity_ < pos) capacity_ *= 2;
111 0 : buffer_ = reinterpret_cast<byte*>(realloc(buffer_, capacity_));
112 : }
113 0 : }
114 :
115 : DebugObject* debug_object() { return debug_object_; }
116 :
117 : byte* buffer() { return buffer_; }
118 :
119 0 : void Align(uintptr_t align) {
120 0 : uintptr_t delta = position_ % align;
121 0 : if (delta == 0) return;
122 0 : uintptr_t padding = align - delta;
123 0 : Ensure(position_ += padding);
124 : DCHECK_EQ(position_ % align, 0);
125 : }
126 :
127 0 : void WriteULEB128(uintptr_t value) {
128 0 : do {
129 0 : uint8_t byte = value & 0x7F;
130 0 : value >>= 7;
131 0 : if (value != 0) byte |= 0x80;
132 0 : Write<uint8_t>(byte);
133 : } while (value != 0);
134 0 : }
135 :
136 0 : void WriteSLEB128(intptr_t value) {
137 : bool more = true;
138 0 : while (more) {
139 0 : int8_t byte = value & 0x7F;
140 0 : bool byte_sign = byte & 0x40;
141 0 : value >>= 7;
142 :
143 0 : if ((value == 0 && !byte_sign) || (value == -1 && byte_sign)) {
144 : more = false;
145 : } else {
146 0 : byte |= 0x80;
147 : }
148 :
149 0 : Write<int8_t>(byte);
150 : }
151 0 : }
152 :
153 : void WriteString(const char* str) {
154 0 : do {
155 0 : Write<char>(*str);
156 : } while (*str++);
157 : }
158 :
159 : private:
160 : template<typename T> friend class Slot;
161 :
162 : template<typename T>
163 : T* RawSlotAt(uintptr_t offset) {
164 : DCHECK(offset < capacity_ && offset + sizeof(T) <= capacity_);
165 0 : return reinterpret_cast<T*>(&buffer_[offset]);
166 : }
167 :
168 : DebugObject* debug_object_;
169 : uintptr_t position_;
170 : uintptr_t capacity_;
171 : byte* buffer_;
172 : };
173 :
174 : class ELFStringTable;
175 :
176 : template<typename THeader>
177 0 : class DebugSectionBase : public ZoneObject {
178 : public:
179 0 : virtual ~DebugSectionBase() { }
180 :
181 0 : virtual void WriteBody(Writer::Slot<THeader> header, Writer* writer) {
182 : uintptr_t start = writer->position();
183 0 : if (WriteBodyInternal(writer)) {
184 : uintptr_t end = writer->position();
185 0 : header->offset = static_cast<uint32_t>(start);
186 : #if defined(__MACH_O)
187 : header->addr = 0;
188 : #endif
189 0 : header->size = end - start;
190 : }
191 0 : }
192 :
193 0 : virtual bool WriteBodyInternal(Writer* writer) {
194 0 : return false;
195 : }
196 :
197 : typedef THeader Header;
198 : };
199 :
200 :
201 : struct MachOSectionHeader {
202 : char sectname[16];
203 : char segname[16];
204 : #if V8_TARGET_ARCH_IA32
205 : uint32_t addr;
206 : uint32_t size;
207 : #else
208 : uint64_t addr;
209 : uint64_t size;
210 : #endif
211 : uint32_t offset;
212 : uint32_t align;
213 : uint32_t reloff;
214 : uint32_t nreloc;
215 : uint32_t flags;
216 : uint32_t reserved1;
217 : uint32_t reserved2;
218 : };
219 :
220 :
221 : class MachOSection : public DebugSectionBase<MachOSectionHeader> {
222 : public:
223 : enum Type {
224 : S_REGULAR = 0x0u,
225 : S_ATTR_COALESCED = 0xbu,
226 : S_ATTR_SOME_INSTRUCTIONS = 0x400u,
227 : S_ATTR_DEBUG = 0x02000000u,
228 : S_ATTR_PURE_INSTRUCTIONS = 0x80000000u
229 : };
230 :
231 : MachOSection(const char* name, const char* segment, uint32_t align,
232 : uint32_t flags)
233 : : name_(name), segment_(segment), align_(align), flags_(flags) {
234 : if (align_ != 0) {
235 : DCHECK(base::bits::IsPowerOfTwo(align));
236 : align_ = WhichPowerOf2(align_);
237 : }
238 : }
239 :
240 0 : virtual ~MachOSection() { }
241 :
242 0 : virtual void PopulateHeader(Writer::Slot<Header> header) {
243 0 : header->addr = 0;
244 0 : header->size = 0;
245 0 : header->offset = 0;
246 0 : header->align = align_;
247 0 : header->reloff = 0;
248 0 : header->nreloc = 0;
249 0 : header->flags = flags_;
250 0 : header->reserved1 = 0;
251 0 : header->reserved2 = 0;
252 0 : memset(header->sectname, 0, sizeof(header->sectname));
253 0 : memset(header->segname, 0, sizeof(header->segname));
254 : DCHECK(strlen(name_) < sizeof(header->sectname));
255 : DCHECK(strlen(segment_) < sizeof(header->segname));
256 0 : strncpy(header->sectname, name_, sizeof(header->sectname));
257 0 : strncpy(header->segname, segment_, sizeof(header->segname));
258 0 : }
259 :
260 : private:
261 : const char* name_;
262 : const char* segment_;
263 : uint32_t align_;
264 : uint32_t flags_;
265 : };
266 :
267 :
268 : struct ELFSectionHeader {
269 : uint32_t name;
270 : uint32_t type;
271 : uintptr_t flags;
272 : uintptr_t address;
273 : uintptr_t offset;
274 : uintptr_t size;
275 : uint32_t link;
276 : uint32_t info;
277 : uintptr_t alignment;
278 : uintptr_t entry_size;
279 : };
280 :
281 :
282 : #if defined(__ELF)
283 : class ELFSection : public DebugSectionBase<ELFSectionHeader> {
284 : public:
285 : enum Type {
286 : TYPE_NULL = 0,
287 : TYPE_PROGBITS = 1,
288 : TYPE_SYMTAB = 2,
289 : TYPE_STRTAB = 3,
290 : TYPE_RELA = 4,
291 : TYPE_HASH = 5,
292 : TYPE_DYNAMIC = 6,
293 : TYPE_NOTE = 7,
294 : TYPE_NOBITS = 8,
295 : TYPE_REL = 9,
296 : TYPE_SHLIB = 10,
297 : TYPE_DYNSYM = 11,
298 : TYPE_LOPROC = 0x70000000,
299 : TYPE_X86_64_UNWIND = 0x70000001,
300 : TYPE_HIPROC = 0x7fffffff,
301 : TYPE_LOUSER = 0x80000000,
302 : TYPE_HIUSER = 0xffffffff
303 : };
304 :
305 : enum Flags {
306 : FLAG_WRITE = 1,
307 : FLAG_ALLOC = 2,
308 : FLAG_EXEC = 4
309 : };
310 :
311 : enum SpecialIndexes {
312 : INDEX_ABSOLUTE = 0xfff1
313 : };
314 :
315 : ELFSection(const char* name, Type type, uintptr_t align)
316 0 : : name_(name), type_(type), align_(align) { }
317 :
318 0 : virtual ~ELFSection() { }
319 :
320 : void PopulateHeader(Writer::Slot<Header> header, ELFStringTable* strtab);
321 :
322 0 : virtual void WriteBody(Writer::Slot<Header> header, Writer* w) {
323 : uintptr_t start = w->position();
324 0 : if (WriteBodyInternal(w)) {
325 : uintptr_t end = w->position();
326 0 : header->offset = start;
327 0 : header->size = end - start;
328 : }
329 0 : }
330 :
331 0 : virtual bool WriteBodyInternal(Writer* w) {
332 0 : return false;
333 : }
334 :
335 : uint16_t index() const { return index_; }
336 0 : void set_index(uint16_t index) { index_ = index; }
337 :
338 : protected:
339 0 : virtual void PopulateHeader(Writer::Slot<Header> header) {
340 0 : header->flags = 0;
341 0 : header->address = 0;
342 0 : header->offset = 0;
343 0 : header->size = 0;
344 0 : header->link = 0;
345 0 : header->info = 0;
346 0 : header->entry_size = 0;
347 0 : }
348 :
349 : private:
350 : const char* name_;
351 : Type type_;
352 : uintptr_t align_;
353 : uint16_t index_;
354 : };
355 : #endif // defined(__ELF)
356 :
357 :
358 : #if defined(__MACH_O)
359 : class MachOTextSection : public MachOSection {
360 : public:
361 : MachOTextSection(uint32_t align, uintptr_t addr, uintptr_t size)
362 : : MachOSection("__text", "__TEXT", align,
363 : MachOSection::S_REGULAR |
364 : MachOSection::S_ATTR_SOME_INSTRUCTIONS |
365 : MachOSection::S_ATTR_PURE_INSTRUCTIONS),
366 : addr_(addr),
367 : size_(size) {}
368 :
369 : protected:
370 : virtual void PopulateHeader(Writer::Slot<Header> header) {
371 : MachOSection::PopulateHeader(header);
372 : header->addr = addr_;
373 : header->size = size_;
374 : }
375 :
376 : private:
377 : uintptr_t addr_;
378 : uintptr_t size_;
379 : };
380 : #endif // defined(__MACH_O)
381 :
382 :
383 : #if defined(__ELF)
384 0 : class FullHeaderELFSection : public ELFSection {
385 : public:
386 : FullHeaderELFSection(const char* name,
387 : Type type,
388 : uintptr_t align,
389 : uintptr_t addr,
390 : uintptr_t offset,
391 : uintptr_t size,
392 : uintptr_t flags)
393 : : ELFSection(name, type, align),
394 : addr_(addr),
395 : offset_(offset),
396 : size_(size),
397 0 : flags_(flags) { }
398 :
399 : protected:
400 0 : virtual void PopulateHeader(Writer::Slot<Header> header) {
401 0 : ELFSection::PopulateHeader(header);
402 0 : header->address = addr_;
403 0 : header->offset = offset_;
404 0 : header->size = size_;
405 0 : header->flags = flags_;
406 0 : }
407 :
408 : private:
409 : uintptr_t addr_;
410 : uintptr_t offset_;
411 : uintptr_t size_;
412 : uintptr_t flags_;
413 : };
414 :
415 :
416 0 : class ELFStringTable : public ELFSection {
417 : public:
418 : explicit ELFStringTable(const char* name)
419 : : ELFSection(name, TYPE_STRTAB, 1),
420 : writer_(nullptr),
421 : offset_(0),
422 0 : size_(0) {}
423 :
424 : uintptr_t Add(const char* str) {
425 0 : if (*str == '\0') return 0;
426 :
427 0 : uintptr_t offset = size_;
428 0 : WriteString(str);
429 : return offset;
430 : }
431 :
432 : void AttachWriter(Writer* w) {
433 0 : writer_ = w;
434 0 : offset_ = writer_->position();
435 :
436 : // First entry in the string table should be an empty string.
437 0 : WriteString("");
438 : }
439 :
440 0 : void DetachWriter() { writer_ = nullptr; }
441 :
442 0 : virtual void WriteBody(Writer::Slot<Header> header, Writer* w) {
443 : DCHECK_NULL(writer_);
444 0 : header->offset = offset_;
445 0 : header->size = size_;
446 0 : }
447 :
448 : private:
449 0 : void WriteString(const char* str) {
450 : uintptr_t written = 0;
451 0 : do {
452 0 : writer_->Write(*str);
453 0 : written++;
454 : } while (*str++);
455 0 : size_ += written;
456 0 : }
457 :
458 : Writer* writer_;
459 :
460 : uintptr_t offset_;
461 : uintptr_t size_;
462 : };
463 :
464 :
465 0 : void ELFSection::PopulateHeader(Writer::Slot<ELFSection::Header> header,
466 : ELFStringTable* strtab) {
467 0 : header->name = static_cast<uint32_t>(strtab->Add(name_));
468 0 : header->type = type_;
469 0 : header->alignment = align_;
470 0 : PopulateHeader(header);
471 0 : }
472 : #endif // defined(__ELF)
473 :
474 :
475 : #if defined(__MACH_O)
476 : class MachO BASE_EMBEDDED {
477 : public:
478 : explicit MachO(Zone* zone) : zone_(zone), sections_(6, zone) { }
479 :
480 : uint32_t AddSection(MachOSection* section) {
481 : sections_.Add(section, zone_);
482 : return sections_.length() - 1;
483 : }
484 :
485 : void Write(Writer* w, uintptr_t code_start, uintptr_t code_size) {
486 : Writer::Slot<MachOHeader> header = WriteHeader(w);
487 : uintptr_t load_command_start = w->position();
488 : Writer::Slot<MachOSegmentCommand> cmd = WriteSegmentCommand(w,
489 : code_start,
490 : code_size);
491 : WriteSections(w, cmd, header, load_command_start);
492 : }
493 :
494 : private:
495 : struct MachOHeader {
496 : uint32_t magic;
497 : uint32_t cputype;
498 : uint32_t cpusubtype;
499 : uint32_t filetype;
500 : uint32_t ncmds;
501 : uint32_t sizeofcmds;
502 : uint32_t flags;
503 : #if V8_TARGET_ARCH_X64
504 : uint32_t reserved;
505 : #endif
506 : };
507 :
508 : struct MachOSegmentCommand {
509 : uint32_t cmd;
510 : uint32_t cmdsize;
511 : char segname[16];
512 : #if V8_TARGET_ARCH_IA32
513 : uint32_t vmaddr;
514 : uint32_t vmsize;
515 : uint32_t fileoff;
516 : uint32_t filesize;
517 : #else
518 : uint64_t vmaddr;
519 : uint64_t vmsize;
520 : uint64_t fileoff;
521 : uint64_t filesize;
522 : #endif
523 : uint32_t maxprot;
524 : uint32_t initprot;
525 : uint32_t nsects;
526 : uint32_t flags;
527 : };
528 :
529 : enum MachOLoadCommandCmd {
530 : LC_SEGMENT_32 = 0x00000001u,
531 : LC_SEGMENT_64 = 0x00000019u
532 : };
533 :
534 :
535 : Writer::Slot<MachOHeader> WriteHeader(Writer* w) {
536 : DCHECK_EQ(w->position(), 0);
537 : Writer::Slot<MachOHeader> header = w->CreateSlotHere<MachOHeader>();
538 : #if V8_TARGET_ARCH_IA32
539 : header->magic = 0xFEEDFACEu;
540 : header->cputype = 7; // i386
541 : header->cpusubtype = 3; // CPU_SUBTYPE_I386_ALL
542 : #elif V8_TARGET_ARCH_X64
543 : header->magic = 0xFEEDFACFu;
544 : header->cputype = 7 | 0x01000000; // i386 | 64-bit ABI
545 : header->cpusubtype = 3; // CPU_SUBTYPE_I386_ALL
546 : header->reserved = 0;
547 : #else
548 : #error Unsupported target architecture.
549 : #endif
550 : header->filetype = 0x1; // MH_OBJECT
551 : header->ncmds = 1;
552 : header->sizeofcmds = 0;
553 : header->flags = 0;
554 : return header;
555 : }
556 :
557 :
558 : Writer::Slot<MachOSegmentCommand> WriteSegmentCommand(Writer* w,
559 : uintptr_t code_start,
560 : uintptr_t code_size) {
561 : Writer::Slot<MachOSegmentCommand> cmd =
562 : w->CreateSlotHere<MachOSegmentCommand>();
563 : #if V8_TARGET_ARCH_IA32
564 : cmd->cmd = LC_SEGMENT_32;
565 : #else
566 : cmd->cmd = LC_SEGMENT_64;
567 : #endif
568 : cmd->vmaddr = code_start;
569 : cmd->vmsize = code_size;
570 : cmd->fileoff = 0;
571 : cmd->filesize = 0;
572 : cmd->maxprot = 7;
573 : cmd->initprot = 7;
574 : cmd->flags = 0;
575 : cmd->nsects = sections_.length();
576 : memset(cmd->segname, 0, 16);
577 : cmd->cmdsize = sizeof(MachOSegmentCommand) + sizeof(MachOSection::Header) *
578 : cmd->nsects;
579 : return cmd;
580 : }
581 :
582 :
583 : void WriteSections(Writer* w,
584 : Writer::Slot<MachOSegmentCommand> cmd,
585 : Writer::Slot<MachOHeader> header,
586 : uintptr_t load_command_start) {
587 : Writer::Slot<MachOSection::Header> headers =
588 : w->CreateSlotsHere<MachOSection::Header>(sections_.length());
589 : cmd->fileoff = w->position();
590 : header->sizeofcmds =
591 : static_cast<uint32_t>(w->position() - load_command_start);
592 : for (int section = 0; section < sections_.length(); ++section) {
593 : sections_[section]->PopulateHeader(headers.at(section));
594 : sections_[section]->WriteBody(headers.at(section), w);
595 : }
596 : cmd->filesize = w->position() - (uintptr_t)cmd->fileoff;
597 : }
598 :
599 : Zone* zone_;
600 : ZoneList<MachOSection*> sections_;
601 : };
602 : #endif // defined(__MACH_O)
603 :
604 :
605 : #if defined(__ELF)
606 : class ELF BASE_EMBEDDED {
607 : public:
608 0 : explicit ELF(Zone* zone) : zone_(zone), sections_(6, zone) {
609 0 : sections_.Add(new(zone) ELFSection("", ELFSection::TYPE_NULL, 0), zone);
610 0 : sections_.Add(new(zone) ELFStringTable(".shstrtab"), zone);
611 0 : }
612 :
613 0 : void Write(Writer* w) {
614 0 : WriteHeader(w);
615 0 : WriteSectionTable(w);
616 0 : WriteSections(w);
617 0 : }
618 :
619 : ELFSection* SectionAt(uint32_t index) {
620 0 : return sections_[index];
621 : }
622 :
623 0 : uint32_t AddSection(ELFSection* section) {
624 0 : sections_.Add(section, zone_);
625 0 : section->set_index(sections_.length() - 1);
626 0 : return sections_.length() - 1;
627 : }
628 :
629 : private:
630 : struct ELFHeader {
631 : uint8_t ident[16];
632 : uint16_t type;
633 : uint16_t machine;
634 : uint32_t version;
635 : uintptr_t entry;
636 : uintptr_t pht_offset;
637 : uintptr_t sht_offset;
638 : uint32_t flags;
639 : uint16_t header_size;
640 : uint16_t pht_entry_size;
641 : uint16_t pht_entry_num;
642 : uint16_t sht_entry_size;
643 : uint16_t sht_entry_num;
644 : uint16_t sht_strtab_index;
645 : };
646 :
647 :
648 0 : void WriteHeader(Writer* w) {
649 : DCHECK_EQ(w->position(), 0);
650 : Writer::Slot<ELFHeader> header = w->CreateSlotHere<ELFHeader>();
651 : #if (V8_TARGET_ARCH_IA32 || V8_TARGET_ARCH_ARM || \
652 : (V8_TARGET_ARCH_X64 && V8_TARGET_ARCH_32_BIT))
653 : const uint8_t ident[16] =
654 : { 0x7f, 'E', 'L', 'F', 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0};
655 : #elif(V8_TARGET_ARCH_X64 && V8_TARGET_ARCH_64_BIT) || \
656 : (V8_TARGET_ARCH_PPC64 && V8_TARGET_LITTLE_ENDIAN)
657 : const uint8_t ident[16] =
658 0 : { 0x7f, 'E', 'L', 'F', 2, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0};
659 : #elif V8_TARGET_ARCH_PPC64 && V8_TARGET_BIG_ENDIAN && V8_OS_LINUX
660 : const uint8_t ident[16] = {0x7f, 'E', 'L', 'F', 2, 2, 1, 0,
661 : 0, 0, 0, 0, 0, 0, 0, 0};
662 : #elif V8_TARGET_ARCH_S390X
663 : const uint8_t ident[16] = {0x7f, 'E', 'L', 'F', 2, 2, 1, 3,
664 : 0, 0, 0, 0, 0, 0, 0, 0};
665 : #elif V8_TARGET_ARCH_S390
666 : const uint8_t ident[16] = {0x7f, 'E', 'L', 'F', 1, 2, 1, 3,
667 : 0, 0, 0, 0, 0, 0, 0, 0};
668 : #else
669 : #error Unsupported target architecture.
670 : #endif
671 0 : memcpy(header->ident, ident, 16);
672 0 : header->type = 1;
673 : #if V8_TARGET_ARCH_IA32
674 : header->machine = 3;
675 : #elif V8_TARGET_ARCH_X64
676 : // Processor identification value for x64 is 62 as defined in
677 : // System V ABI, AMD64 Supplement
678 : // http://www.x86-64.org/documentation/abi.pdf
679 0 : header->machine = 62;
680 : #elif V8_TARGET_ARCH_ARM
681 : // Set to EM_ARM, defined as 40, in "ARM ELF File Format" at
682 : // infocenter.arm.com/help/topic/com.arm.doc.dui0101a/DUI0101A_Elf.pdf
683 : header->machine = 40;
684 : #elif V8_TARGET_ARCH_PPC64 && V8_OS_LINUX
685 : // Set to EM_PPC64, defined as 21, in Power ABI,
686 : // Join the next 4 lines, omitting the spaces and double-slashes.
687 : // https://www-03.ibm.com/technologyconnect/tgcm/TGCMFileServlet.wss/
688 : // ABI64BitOpenPOWERv1.1_16July2015_pub.pdf?
689 : // id=B81AEC1A37F5DAF185257C3E004E8845&linkid=1n0000&c_t=
690 : // c9xw7v5dzsj7gt1ifgf4cjbcnskqptmr
691 : header->machine = 21;
692 : #elif V8_TARGET_ARCH_S390
693 : // Processor identification value is 22 (EM_S390) as defined in the ABI:
694 : // http://refspecs.linuxbase.org/ELF/zSeries/lzsabi0_s390.html#AEN1691
695 : // http://refspecs.linuxbase.org/ELF/zSeries/lzsabi0_zSeries.html#AEN1599
696 : header->machine = 22;
697 : #else
698 : #error Unsupported target architecture.
699 : #endif
700 0 : header->version = 1;
701 0 : header->entry = 0;
702 0 : header->pht_offset = 0;
703 0 : header->sht_offset = sizeof(ELFHeader); // Section table follows header.
704 0 : header->flags = 0;
705 0 : header->header_size = sizeof(ELFHeader);
706 0 : header->pht_entry_size = 0;
707 0 : header->pht_entry_num = 0;
708 0 : header->sht_entry_size = sizeof(ELFSection::Header);
709 0 : header->sht_entry_num = sections_.length();
710 0 : header->sht_strtab_index = 1;
711 0 : }
712 :
713 0 : void WriteSectionTable(Writer* w) {
714 : // Section headers table immediately follows file header.
715 : DCHECK(w->position() == sizeof(ELFHeader));
716 :
717 : Writer::Slot<ELFSection::Header> headers =
718 0 : w->CreateSlotsHere<ELFSection::Header>(sections_.length());
719 :
720 : // String table for section table is the first section.
721 : ELFStringTable* strtab = static_cast<ELFStringTable*>(SectionAt(1));
722 : strtab->AttachWriter(w);
723 0 : for (int i = 0, length = sections_.length();
724 : i < length;
725 : i++) {
726 0 : sections_[i]->PopulateHeader(headers.at(i), strtab);
727 : }
728 : strtab->DetachWriter();
729 0 : }
730 :
731 : int SectionHeaderPosition(uint32_t section_index) {
732 : return sizeof(ELFHeader) + sizeof(ELFSection::Header) * section_index;
733 : }
734 :
735 0 : void WriteSections(Writer* w) {
736 : Writer::Slot<ELFSection::Header> headers =
737 : w->SlotAt<ELFSection::Header>(sizeof(ELFHeader));
738 :
739 0 : for (int i = 0, length = sections_.length();
740 : i < length;
741 : i++) {
742 0 : sections_[i]->WriteBody(headers.at(i), w);
743 : }
744 0 : }
745 :
746 : Zone* zone_;
747 : ZoneList<ELFSection*> sections_;
748 : };
749 :
750 :
751 : class ELFSymbol BASE_EMBEDDED {
752 : public:
753 : enum Type {
754 : TYPE_NOTYPE = 0,
755 : TYPE_OBJECT = 1,
756 : TYPE_FUNC = 2,
757 : TYPE_SECTION = 3,
758 : TYPE_FILE = 4,
759 : TYPE_LOPROC = 13,
760 : TYPE_HIPROC = 15
761 : };
762 :
763 : enum Binding {
764 : BIND_LOCAL = 0,
765 : BIND_GLOBAL = 1,
766 : BIND_WEAK = 2,
767 : BIND_LOPROC = 13,
768 : BIND_HIPROC = 15
769 : };
770 :
771 : ELFSymbol(const char* name,
772 : uintptr_t value,
773 : uintptr_t size,
774 : Binding binding,
775 : Type type,
776 : uint16_t section)
777 : : name(name),
778 : value(value),
779 : size(size),
780 : info((binding << 4) | type),
781 : other(0),
782 0 : section(section) {
783 : }
784 :
785 : Binding binding() const {
786 0 : return static_cast<Binding>(info >> 4);
787 : }
788 : #if (V8_TARGET_ARCH_IA32 || V8_TARGET_ARCH_ARM || \
789 : (V8_TARGET_ARCH_X64 && V8_TARGET_ARCH_32_BIT) || \
790 : (V8_TARGET_ARCH_S390 && V8_TARGET_ARCH_32_BIT))
791 : struct SerializedLayout {
792 : SerializedLayout(uint32_t name,
793 : uintptr_t value,
794 : uintptr_t size,
795 : Binding binding,
796 : Type type,
797 : uint16_t section)
798 : : name(name),
799 : value(value),
800 : size(size),
801 : info((binding << 4) | type),
802 : other(0),
803 : section(section) {
804 : }
805 :
806 : uint32_t name;
807 : uintptr_t value;
808 : uintptr_t size;
809 : uint8_t info;
810 : uint8_t other;
811 : uint16_t section;
812 : };
813 : #elif(V8_TARGET_ARCH_X64 && V8_TARGET_ARCH_64_BIT) || \
814 : (V8_TARGET_ARCH_PPC64 && V8_OS_LINUX) || V8_TARGET_ARCH_S390X
815 : struct SerializedLayout {
816 : SerializedLayout(uint32_t name,
817 : uintptr_t value,
818 : uintptr_t size,
819 : Binding binding,
820 : Type type,
821 : uint16_t section)
822 : : name(name),
823 : info((binding << 4) | type),
824 : other(0),
825 : section(section),
826 : value(value),
827 : size(size) {
828 : }
829 :
830 : uint32_t name;
831 : uint8_t info;
832 : uint8_t other;
833 : uint16_t section;
834 : uintptr_t value;
835 : uintptr_t size;
836 : };
837 : #endif
838 :
839 0 : void Write(Writer::Slot<SerializedLayout> s, ELFStringTable* t) {
840 : // Convert symbol names from strings to indexes in the string table.
841 0 : s->name = static_cast<uint32_t>(t->Add(name));
842 0 : s->value = value;
843 0 : s->size = size;
844 0 : s->info = info;
845 0 : s->other = other;
846 0 : s->section = section;
847 0 : }
848 :
849 : private:
850 : const char* name;
851 : uintptr_t value;
852 : uintptr_t size;
853 : uint8_t info;
854 : uint8_t other;
855 : uint16_t section;
856 : };
857 :
858 :
859 0 : class ELFSymbolTable : public ELFSection {
860 : public:
861 0 : ELFSymbolTable(const char* name, Zone* zone)
862 : : ELFSection(name, TYPE_SYMTAB, sizeof(uintptr_t)),
863 : locals_(1, zone),
864 0 : globals_(1, zone) {
865 0 : }
866 :
867 0 : virtual void WriteBody(Writer::Slot<Header> header, Writer* w) {
868 0 : w->Align(header->alignment);
869 0 : int total_symbols = locals_.length() + globals_.length() + 1;
870 0 : header->offset = w->position();
871 :
872 : Writer::Slot<ELFSymbol::SerializedLayout> symbols =
873 0 : w->CreateSlotsHere<ELFSymbol::SerializedLayout>(total_symbols);
874 :
875 0 : header->size = w->position() - header->offset;
876 :
877 : // String table for this symbol table should follow it in the section table.
878 : ELFStringTable* strtab =
879 0 : static_cast<ELFStringTable*>(w->debug_object()->SectionAt(index() + 1));
880 : strtab->AttachWriter(w);
881 : symbols.at(0).set(ELFSymbol::SerializedLayout(0,
882 : 0,
883 : 0,
884 : ELFSymbol::BIND_LOCAL,
885 : ELFSymbol::TYPE_NOTYPE,
886 : 0));
887 0 : WriteSymbolsList(&locals_, symbols.at(1), strtab);
888 0 : WriteSymbolsList(&globals_, symbols.at(locals_.length() + 1), strtab);
889 : strtab->DetachWriter();
890 0 : }
891 :
892 0 : void Add(const ELFSymbol& symbol, Zone* zone) {
893 0 : if (symbol.binding() == ELFSymbol::BIND_LOCAL) {
894 0 : locals_.Add(symbol, zone);
895 : } else {
896 0 : globals_.Add(symbol, zone);
897 : }
898 0 : }
899 :
900 : protected:
901 0 : virtual void PopulateHeader(Writer::Slot<Header> header) {
902 0 : ELFSection::PopulateHeader(header);
903 : // We are assuming that string table will follow symbol table.
904 0 : header->link = index() + 1;
905 0 : header->info = locals_.length() + 1;
906 0 : header->entry_size = sizeof(ELFSymbol::SerializedLayout);
907 0 : }
908 :
909 : private:
910 0 : void WriteSymbolsList(const ZoneList<ELFSymbol>* src,
911 : Writer::Slot<ELFSymbol::SerializedLayout> dst,
912 : ELFStringTable* strtab) {
913 0 : for (int i = 0, len = src->length();
914 : i < len;
915 : i++) {
916 0 : src->at(i).Write(dst.at(i), strtab);
917 : }
918 0 : }
919 :
920 : ZoneList<ELFSymbol> locals_;
921 : ZoneList<ELFSymbol> globals_;
922 : };
923 : #endif // defined(__ELF)
924 :
925 :
926 : class LineInfo : public Malloced {
927 : public:
928 : void SetPosition(intptr_t pc, int pos, bool is_statement) {
929 0 : AddPCInfo(PCInfo(pc, pos, is_statement));
930 : }
931 :
932 : struct PCInfo {
933 : PCInfo(intptr_t pc, int pos, bool is_statement)
934 0 : : pc_(pc), pos_(pos), is_statement_(is_statement) {}
935 :
936 : intptr_t pc_;
937 : int pos_;
938 : bool is_statement_;
939 : };
940 :
941 : std::vector<PCInfo>* pc_info() { return &pc_info_; }
942 :
943 : private:
944 0 : void AddPCInfo(const PCInfo& pc_info) { pc_info_.push_back(pc_info); }
945 :
946 : std::vector<PCInfo> pc_info_;
947 : };
948 :
949 :
950 : class CodeDescription BASE_EMBEDDED {
951 : public:
952 : #if V8_TARGET_ARCH_X64
953 : enum StackState {
954 : POST_RBP_PUSH,
955 : POST_RBP_SET,
956 : POST_RBP_POP,
957 : STACK_STATE_MAX
958 : };
959 : #endif
960 :
961 : CodeDescription(const char* name, Code* code, SharedFunctionInfo* shared,
962 : LineInfo* lineinfo)
963 0 : : name_(name), code_(code), shared_info_(shared), lineinfo_(lineinfo) {}
964 :
965 : const char* name() const {
966 : return name_;
967 : }
968 :
969 : LineInfo* lineinfo() const { return lineinfo_; }
970 :
971 : bool is_function() const {
972 : Code::Kind kind = code_->kind();
973 : return kind == Code::OPTIMIZED_FUNCTION;
974 : }
975 :
976 0 : bool has_scope_info() const { return shared_info_ != nullptr; }
977 :
978 : ScopeInfo* scope_info() const {
979 : DCHECK(has_scope_info());
980 : return shared_info_->scope_info();
981 : }
982 :
983 : uintptr_t CodeStart() const {
984 0 : return reinterpret_cast<uintptr_t>(code_->instruction_start());
985 : }
986 :
987 : uintptr_t CodeEnd() const {
988 0 : return reinterpret_cast<uintptr_t>(code_->instruction_end());
989 : }
990 :
991 0 : uintptr_t CodeSize() const {
992 0 : return CodeEnd() - CodeStart();
993 : }
994 :
995 0 : bool has_script() {
996 0 : return shared_info_ != nullptr && shared_info_->script()->IsScript();
997 : }
998 :
999 : Script* script() { return Script::cast(shared_info_->script()); }
1000 :
1001 0 : bool IsLineInfoAvailable() {
1002 0 : return has_script() && script()->source()->IsString() &&
1003 0 : script()->HasValidSource() && script()->name()->IsString() &&
1004 0 : lineinfo_ != nullptr;
1005 : }
1006 :
1007 : #if V8_TARGET_ARCH_X64
1008 : uintptr_t GetStackStateStartAddress(StackState state) const {
1009 : DCHECK(state < STACK_STATE_MAX);
1010 0 : return stack_state_start_addresses_[state];
1011 : }
1012 :
1013 : void SetStackStateStartAddress(StackState state, uintptr_t addr) {
1014 : DCHECK(state < STACK_STATE_MAX);
1015 0 : stack_state_start_addresses_[state] = addr;
1016 : }
1017 : #endif
1018 :
1019 0 : std::unique_ptr<char[]> GetFilename() {
1020 0 : return String::cast(script()->name())->ToCString();
1021 : }
1022 :
1023 0 : int GetScriptLineNumber(int pos) { return script()->GetLineNumber(pos) + 1; }
1024 :
1025 :
1026 : private:
1027 : const char* name_;
1028 : Code* code_;
1029 : SharedFunctionInfo* shared_info_;
1030 : LineInfo* lineinfo_;
1031 : #if V8_TARGET_ARCH_X64
1032 : uintptr_t stack_state_start_addresses_[STACK_STATE_MAX];
1033 : #endif
1034 : };
1035 :
1036 : #if defined(__ELF)
1037 0 : static void CreateSymbolsTable(CodeDescription* desc,
1038 : Zone* zone,
1039 : ELF* elf,
1040 : int text_section_index) {
1041 0 : ELFSymbolTable* symtab = new(zone) ELFSymbolTable(".symtab", zone);
1042 : ELFStringTable* strtab = new(zone) ELFStringTable(".strtab");
1043 :
1044 : // Symbol table should be followed by the linked string table.
1045 0 : elf->AddSection(symtab);
1046 0 : elf->AddSection(strtab);
1047 :
1048 : symtab->Add(ELFSymbol("V8 Code",
1049 : 0,
1050 : 0,
1051 : ELFSymbol::BIND_LOCAL,
1052 : ELFSymbol::TYPE_FILE,
1053 : ELFSection::INDEX_ABSOLUTE),
1054 0 : zone);
1055 :
1056 : symtab->Add(ELFSymbol(desc->name(),
1057 : 0,
1058 : desc->CodeSize(),
1059 : ELFSymbol::BIND_GLOBAL,
1060 : ELFSymbol::TYPE_FUNC,
1061 : text_section_index),
1062 0 : zone);
1063 0 : }
1064 : #endif // defined(__ELF)
1065 :
1066 :
1067 0 : class DebugInfoSection : public DebugSection {
1068 : public:
1069 : explicit DebugInfoSection(CodeDescription* desc)
1070 : #if defined(__ELF)
1071 : : ELFSection(".debug_info", TYPE_PROGBITS, 1),
1072 : #else
1073 : : MachOSection("__debug_info",
1074 : "__DWARF",
1075 : 1,
1076 : MachOSection::S_REGULAR | MachOSection::S_ATTR_DEBUG),
1077 : #endif
1078 0 : desc_(desc) { }
1079 :
1080 : // DWARF2 standard
1081 : enum DWARF2LocationOp {
1082 : DW_OP_reg0 = 0x50,
1083 : DW_OP_reg1 = 0x51,
1084 : DW_OP_reg2 = 0x52,
1085 : DW_OP_reg3 = 0x53,
1086 : DW_OP_reg4 = 0x54,
1087 : DW_OP_reg5 = 0x55,
1088 : DW_OP_reg6 = 0x56,
1089 : DW_OP_reg7 = 0x57,
1090 : DW_OP_reg8 = 0x58,
1091 : DW_OP_reg9 = 0x59,
1092 : DW_OP_reg10 = 0x5a,
1093 : DW_OP_reg11 = 0x5b,
1094 : DW_OP_reg12 = 0x5c,
1095 : DW_OP_reg13 = 0x5d,
1096 : DW_OP_reg14 = 0x5e,
1097 : DW_OP_reg15 = 0x5f,
1098 : DW_OP_reg16 = 0x60,
1099 : DW_OP_reg17 = 0x61,
1100 : DW_OP_reg18 = 0x62,
1101 : DW_OP_reg19 = 0x63,
1102 : DW_OP_reg20 = 0x64,
1103 : DW_OP_reg21 = 0x65,
1104 : DW_OP_reg22 = 0x66,
1105 : DW_OP_reg23 = 0x67,
1106 : DW_OP_reg24 = 0x68,
1107 : DW_OP_reg25 = 0x69,
1108 : DW_OP_reg26 = 0x6a,
1109 : DW_OP_reg27 = 0x6b,
1110 : DW_OP_reg28 = 0x6c,
1111 : DW_OP_reg29 = 0x6d,
1112 : DW_OP_reg30 = 0x6e,
1113 : DW_OP_reg31 = 0x6f,
1114 : DW_OP_fbreg = 0x91 // 1 param: SLEB128 offset
1115 : };
1116 :
1117 : enum DWARF2Encoding {
1118 : DW_ATE_ADDRESS = 0x1,
1119 : DW_ATE_SIGNED = 0x5
1120 : };
1121 :
1122 0 : bool WriteBodyInternal(Writer* w) {
1123 : uintptr_t cu_start = w->position();
1124 : Writer::Slot<uint32_t> size = w->CreateSlotHere<uint32_t>();
1125 : uintptr_t start = w->position();
1126 0 : w->Write<uint16_t>(2); // DWARF version.
1127 0 : w->Write<uint32_t>(0); // Abbreviation table offset.
1128 0 : w->Write<uint8_t>(sizeof(intptr_t));
1129 :
1130 0 : w->WriteULEB128(1); // Abbreviation code.
1131 0 : w->WriteString(desc_->GetFilename().get());
1132 0 : w->Write<intptr_t>(desc_->CodeStart());
1133 0 : w->Write<intptr_t>(desc_->CodeStart() + desc_->CodeSize());
1134 0 : w->Write<uint32_t>(0);
1135 :
1136 0 : uint32_t ty_offset = static_cast<uint32_t>(w->position() - cu_start);
1137 0 : w->WriteULEB128(3);
1138 0 : w->Write<uint8_t>(kPointerSize);
1139 : w->WriteString("v8value");
1140 :
1141 0 : if (desc_->has_scope_info()) {
1142 : ScopeInfo* scope = desc_->scope_info();
1143 0 : w->WriteULEB128(2);
1144 0 : w->WriteString(desc_->name());
1145 0 : w->Write<intptr_t>(desc_->CodeStart());
1146 0 : w->Write<intptr_t>(desc_->CodeStart() + desc_->CodeSize());
1147 : Writer::Slot<uint32_t> fb_block_size = w->CreateSlotHere<uint32_t>();
1148 : uintptr_t fb_block_start = w->position();
1149 : #if V8_TARGET_ARCH_IA32
1150 : w->Write<uint8_t>(DW_OP_reg5); // The frame pointer's here on ia32
1151 : #elif V8_TARGET_ARCH_X64
1152 0 : w->Write<uint8_t>(DW_OP_reg6); // and here on x64.
1153 : #elif V8_TARGET_ARCH_ARM
1154 : UNIMPLEMENTED();
1155 : #elif V8_TARGET_ARCH_MIPS
1156 : UNIMPLEMENTED();
1157 : #elif V8_TARGET_ARCH_MIPS64
1158 : UNIMPLEMENTED();
1159 : #elif V8_TARGET_ARCH_PPC64 && V8_OS_LINUX
1160 : w->Write<uint8_t>(DW_OP_reg31); // The frame pointer is here on PPC64.
1161 : #elif V8_TARGET_ARCH_S390
1162 : w->Write<uint8_t>(DW_OP_reg11); // The frame pointer's here on S390.
1163 : #else
1164 : #error Unsupported target architecture.
1165 : #endif
1166 0 : fb_block_size.set(static_cast<uint32_t>(w->position() - fb_block_start));
1167 :
1168 0 : int params = scope->ParameterCount();
1169 0 : int slots = scope->StackLocalCount();
1170 0 : int context_slots = scope->ContextLocalCount();
1171 : // The real slot ID is internal_slots + context_slot_id.
1172 : int internal_slots = Context::MIN_CONTEXT_SLOTS;
1173 0 : int locals = scope->StackLocalCount();
1174 : int current_abbreviation = 4;
1175 :
1176 0 : for (int param = 0; param < params; ++param) {
1177 0 : w->WriteULEB128(current_abbreviation++);
1178 : w->WriteString(
1179 0 : scope->ParameterName(param)->ToCString(DISALLOW_NULLS).get());
1180 0 : w->Write<uint32_t>(ty_offset);
1181 : Writer::Slot<uint32_t> block_size = w->CreateSlotHere<uint32_t>();
1182 : uintptr_t block_start = w->position();
1183 0 : w->Write<uint8_t>(DW_OP_fbreg);
1184 : w->WriteSLEB128(
1185 0 : JavaScriptFrameConstants::kLastParameterOffset +
1186 0 : kPointerSize * (params - param - 1));
1187 0 : block_size.set(static_cast<uint32_t>(w->position() - block_start));
1188 : }
1189 :
1190 : EmbeddedVector<char, 256> buffer;
1191 : StringBuilder builder(buffer.start(), buffer.length());
1192 :
1193 0 : for (int slot = 0; slot < slots; ++slot) {
1194 0 : w->WriteULEB128(current_abbreviation++);
1195 : builder.Reset();
1196 0 : builder.AddFormatted("slot%d", slot);
1197 0 : w->WriteString(builder.Finalize());
1198 : }
1199 :
1200 : // See contexts.h for more information.
1201 : DCHECK_EQ(Context::MIN_CONTEXT_SLOTS, 4);
1202 : DCHECK_EQ(Context::CLOSURE_INDEX, 0);
1203 : DCHECK_EQ(Context::PREVIOUS_INDEX, 1);
1204 : DCHECK_EQ(Context::EXTENSION_INDEX, 2);
1205 : DCHECK_EQ(Context::NATIVE_CONTEXT_INDEX, 3);
1206 0 : w->WriteULEB128(current_abbreviation++);
1207 : w->WriteString(".closure");
1208 0 : w->WriteULEB128(current_abbreviation++);
1209 : w->WriteString(".previous");
1210 0 : w->WriteULEB128(current_abbreviation++);
1211 : w->WriteString(".extension");
1212 0 : w->WriteULEB128(current_abbreviation++);
1213 : w->WriteString(".native_context");
1214 :
1215 0 : for (int context_slot = 0;
1216 : context_slot < context_slots;
1217 : ++context_slot) {
1218 0 : w->WriteULEB128(current_abbreviation++);
1219 : builder.Reset();
1220 0 : builder.AddFormatted("context_slot%d", context_slot + internal_slots);
1221 0 : w->WriteString(builder.Finalize());
1222 : }
1223 :
1224 0 : for (int local = 0; local < locals; ++local) {
1225 0 : w->WriteULEB128(current_abbreviation++);
1226 : w->WriteString(
1227 0 : scope->StackLocalName(local)->ToCString(DISALLOW_NULLS).get());
1228 0 : w->Write<uint32_t>(ty_offset);
1229 : Writer::Slot<uint32_t> block_size = w->CreateSlotHere<uint32_t>();
1230 : uintptr_t block_start = w->position();
1231 0 : w->Write<uint8_t>(DW_OP_fbreg);
1232 : w->WriteSLEB128(
1233 0 : JavaScriptFrameConstants::kLocal0Offset -
1234 0 : kPointerSize * local);
1235 0 : block_size.set(static_cast<uint32_t>(w->position() - block_start));
1236 : }
1237 :
1238 : {
1239 0 : w->WriteULEB128(current_abbreviation++);
1240 : w->WriteString("__function");
1241 0 : w->Write<uint32_t>(ty_offset);
1242 : Writer::Slot<uint32_t> block_size = w->CreateSlotHere<uint32_t>();
1243 : uintptr_t block_start = w->position();
1244 0 : w->Write<uint8_t>(DW_OP_fbreg);
1245 0 : w->WriteSLEB128(JavaScriptFrameConstants::kFunctionOffset);
1246 0 : block_size.set(static_cast<uint32_t>(w->position() - block_start));
1247 : }
1248 :
1249 : {
1250 0 : w->WriteULEB128(current_abbreviation++);
1251 : w->WriteString("__context");
1252 0 : w->Write<uint32_t>(ty_offset);
1253 : Writer::Slot<uint32_t> block_size = w->CreateSlotHere<uint32_t>();
1254 : uintptr_t block_start = w->position();
1255 0 : w->Write<uint8_t>(DW_OP_fbreg);
1256 0 : w->WriteSLEB128(StandardFrameConstants::kContextOffset);
1257 0 : block_size.set(static_cast<uint32_t>(w->position() - block_start));
1258 : }
1259 :
1260 0 : w->WriteULEB128(0); // Terminate the sub program.
1261 : }
1262 :
1263 0 : w->WriteULEB128(0); // Terminate the compile unit.
1264 0 : size.set(static_cast<uint32_t>(w->position() - start));
1265 0 : return true;
1266 : }
1267 :
1268 : private:
1269 : CodeDescription* desc_;
1270 : };
1271 :
1272 :
1273 0 : class DebugAbbrevSection : public DebugSection {
1274 : public:
1275 : explicit DebugAbbrevSection(CodeDescription* desc)
1276 : #ifdef __ELF
1277 : : ELFSection(".debug_abbrev", TYPE_PROGBITS, 1),
1278 : #else
1279 : : MachOSection("__debug_abbrev",
1280 : "__DWARF",
1281 : 1,
1282 : MachOSection::S_REGULAR | MachOSection::S_ATTR_DEBUG),
1283 : #endif
1284 0 : desc_(desc) { }
1285 :
1286 : // DWARF2 standard, figure 14.
1287 : enum DWARF2Tags {
1288 : DW_TAG_FORMAL_PARAMETER = 0x05,
1289 : DW_TAG_POINTER_TYPE = 0xf,
1290 : DW_TAG_COMPILE_UNIT = 0x11,
1291 : DW_TAG_STRUCTURE_TYPE = 0x13,
1292 : DW_TAG_BASE_TYPE = 0x24,
1293 : DW_TAG_SUBPROGRAM = 0x2e,
1294 : DW_TAG_VARIABLE = 0x34
1295 : };
1296 :
1297 : // DWARF2 standard, figure 16.
1298 : enum DWARF2ChildrenDetermination {
1299 : DW_CHILDREN_NO = 0,
1300 : DW_CHILDREN_YES = 1
1301 : };
1302 :
1303 : // DWARF standard, figure 17.
1304 : enum DWARF2Attribute {
1305 : DW_AT_LOCATION = 0x2,
1306 : DW_AT_NAME = 0x3,
1307 : DW_AT_BYTE_SIZE = 0xb,
1308 : DW_AT_STMT_LIST = 0x10,
1309 : DW_AT_LOW_PC = 0x11,
1310 : DW_AT_HIGH_PC = 0x12,
1311 : DW_AT_ENCODING = 0x3e,
1312 : DW_AT_FRAME_BASE = 0x40,
1313 : DW_AT_TYPE = 0x49
1314 : };
1315 :
1316 : // DWARF2 standard, figure 19.
1317 : enum DWARF2AttributeForm {
1318 : DW_FORM_ADDR = 0x1,
1319 : DW_FORM_BLOCK4 = 0x4,
1320 : DW_FORM_STRING = 0x8,
1321 : DW_FORM_DATA4 = 0x6,
1322 : DW_FORM_BLOCK = 0x9,
1323 : DW_FORM_DATA1 = 0xb,
1324 : DW_FORM_FLAG = 0xc,
1325 : DW_FORM_REF4 = 0x13
1326 : };
1327 :
1328 0 : void WriteVariableAbbreviation(Writer* w,
1329 : int abbreviation_code,
1330 : bool has_value,
1331 : bool is_parameter) {
1332 0 : w->WriteULEB128(abbreviation_code);
1333 0 : w->WriteULEB128(is_parameter ? DW_TAG_FORMAL_PARAMETER : DW_TAG_VARIABLE);
1334 0 : w->Write<uint8_t>(DW_CHILDREN_NO);
1335 0 : w->WriteULEB128(DW_AT_NAME);
1336 0 : w->WriteULEB128(DW_FORM_STRING);
1337 0 : if (has_value) {
1338 0 : w->WriteULEB128(DW_AT_TYPE);
1339 0 : w->WriteULEB128(DW_FORM_REF4);
1340 0 : w->WriteULEB128(DW_AT_LOCATION);
1341 0 : w->WriteULEB128(DW_FORM_BLOCK4);
1342 : }
1343 0 : w->WriteULEB128(0);
1344 0 : w->WriteULEB128(0);
1345 0 : }
1346 :
1347 0 : bool WriteBodyInternal(Writer* w) {
1348 : int current_abbreviation = 1;
1349 0 : bool extra_info = desc_->has_scope_info();
1350 : DCHECK(desc_->IsLineInfoAvailable());
1351 0 : w->WriteULEB128(current_abbreviation++);
1352 0 : w->WriteULEB128(DW_TAG_COMPILE_UNIT);
1353 0 : w->Write<uint8_t>(extra_info ? DW_CHILDREN_YES : DW_CHILDREN_NO);
1354 0 : w->WriteULEB128(DW_AT_NAME);
1355 0 : w->WriteULEB128(DW_FORM_STRING);
1356 0 : w->WriteULEB128(DW_AT_LOW_PC);
1357 0 : w->WriteULEB128(DW_FORM_ADDR);
1358 0 : w->WriteULEB128(DW_AT_HIGH_PC);
1359 0 : w->WriteULEB128(DW_FORM_ADDR);
1360 0 : w->WriteULEB128(DW_AT_STMT_LIST);
1361 0 : w->WriteULEB128(DW_FORM_DATA4);
1362 0 : w->WriteULEB128(0);
1363 0 : w->WriteULEB128(0);
1364 :
1365 0 : if (extra_info) {
1366 0 : ScopeInfo* scope = desc_->scope_info();
1367 0 : int params = scope->ParameterCount();
1368 0 : int slots = scope->StackLocalCount();
1369 0 : int context_slots = scope->ContextLocalCount();
1370 : // The real slot ID is internal_slots + context_slot_id.
1371 : int internal_slots = Context::MIN_CONTEXT_SLOTS;
1372 0 : int locals = scope->StackLocalCount();
1373 : // Total children is params + slots + context_slots + internal_slots +
1374 : // locals + 2 (__function and __context).
1375 :
1376 : // The extra duplication below seems to be necessary to keep
1377 : // gdb from getting upset on OSX.
1378 0 : w->WriteULEB128(current_abbreviation++); // Abbreviation code.
1379 0 : w->WriteULEB128(DW_TAG_SUBPROGRAM);
1380 0 : w->Write<uint8_t>(DW_CHILDREN_YES);
1381 0 : w->WriteULEB128(DW_AT_NAME);
1382 0 : w->WriteULEB128(DW_FORM_STRING);
1383 0 : w->WriteULEB128(DW_AT_LOW_PC);
1384 0 : w->WriteULEB128(DW_FORM_ADDR);
1385 0 : w->WriteULEB128(DW_AT_HIGH_PC);
1386 0 : w->WriteULEB128(DW_FORM_ADDR);
1387 0 : w->WriteULEB128(DW_AT_FRAME_BASE);
1388 0 : w->WriteULEB128(DW_FORM_BLOCK4);
1389 0 : w->WriteULEB128(0);
1390 0 : w->WriteULEB128(0);
1391 :
1392 0 : w->WriteULEB128(current_abbreviation++);
1393 0 : w->WriteULEB128(DW_TAG_STRUCTURE_TYPE);
1394 0 : w->Write<uint8_t>(DW_CHILDREN_NO);
1395 0 : w->WriteULEB128(DW_AT_BYTE_SIZE);
1396 0 : w->WriteULEB128(DW_FORM_DATA1);
1397 0 : w->WriteULEB128(DW_AT_NAME);
1398 0 : w->WriteULEB128(DW_FORM_STRING);
1399 0 : w->WriteULEB128(0);
1400 0 : w->WriteULEB128(0);
1401 :
1402 0 : for (int param = 0; param < params; ++param) {
1403 0 : WriteVariableAbbreviation(w, current_abbreviation++, true, true);
1404 : }
1405 :
1406 0 : for (int slot = 0; slot < slots; ++slot) {
1407 0 : WriteVariableAbbreviation(w, current_abbreviation++, false, false);
1408 : }
1409 :
1410 0 : for (int internal_slot = 0;
1411 : internal_slot < internal_slots;
1412 : ++internal_slot) {
1413 0 : WriteVariableAbbreviation(w, current_abbreviation++, false, false);
1414 : }
1415 :
1416 0 : for (int context_slot = 0;
1417 : context_slot < context_slots;
1418 : ++context_slot) {
1419 0 : WriteVariableAbbreviation(w, current_abbreviation++, false, false);
1420 : }
1421 :
1422 0 : for (int local = 0; local < locals; ++local) {
1423 0 : WriteVariableAbbreviation(w, current_abbreviation++, true, false);
1424 : }
1425 :
1426 : // The function.
1427 0 : WriteVariableAbbreviation(w, current_abbreviation++, true, false);
1428 :
1429 : // The context.
1430 0 : WriteVariableAbbreviation(w, current_abbreviation++, true, false);
1431 :
1432 0 : w->WriteULEB128(0); // Terminate the sibling list.
1433 : }
1434 :
1435 0 : w->WriteULEB128(0); // Terminate the table.
1436 0 : return true;
1437 : }
1438 :
1439 : private:
1440 : CodeDescription* desc_;
1441 : };
1442 :
1443 :
1444 0 : class DebugLineSection : public DebugSection {
1445 : public:
1446 : explicit DebugLineSection(CodeDescription* desc)
1447 : #ifdef __ELF
1448 : : ELFSection(".debug_line", TYPE_PROGBITS, 1),
1449 : #else
1450 : : MachOSection("__debug_line",
1451 : "__DWARF",
1452 : 1,
1453 : MachOSection::S_REGULAR | MachOSection::S_ATTR_DEBUG),
1454 : #endif
1455 0 : desc_(desc) { }
1456 :
1457 : // DWARF2 standard, figure 34.
1458 : enum DWARF2Opcodes {
1459 : DW_LNS_COPY = 1,
1460 : DW_LNS_ADVANCE_PC = 2,
1461 : DW_LNS_ADVANCE_LINE = 3,
1462 : DW_LNS_SET_FILE = 4,
1463 : DW_LNS_SET_COLUMN = 5,
1464 : DW_LNS_NEGATE_STMT = 6
1465 : };
1466 :
1467 : // DWARF2 standard, figure 35.
1468 : enum DWARF2ExtendedOpcode {
1469 : DW_LNE_END_SEQUENCE = 1,
1470 : DW_LNE_SET_ADDRESS = 2,
1471 : DW_LNE_DEFINE_FILE = 3
1472 : };
1473 :
1474 0 : bool WriteBodyInternal(Writer* w) {
1475 : // Write prologue.
1476 : Writer::Slot<uint32_t> total_length = w->CreateSlotHere<uint32_t>();
1477 : uintptr_t start = w->position();
1478 :
1479 : // Used for special opcodes
1480 0 : const int8_t line_base = 1;
1481 0 : const uint8_t line_range = 7;
1482 : const int8_t max_line_incr = (line_base + line_range - 1);
1483 0 : const uint8_t opcode_base = DW_LNS_NEGATE_STMT + 1;
1484 :
1485 0 : w->Write<uint16_t>(2); // Field version.
1486 : Writer::Slot<uint32_t> prologue_length = w->CreateSlotHere<uint32_t>();
1487 : uintptr_t prologue_start = w->position();
1488 0 : w->Write<uint8_t>(1); // Field minimum_instruction_length.
1489 0 : w->Write<uint8_t>(1); // Field default_is_stmt.
1490 0 : w->Write<int8_t>(line_base); // Field line_base.
1491 0 : w->Write<uint8_t>(line_range); // Field line_range.
1492 0 : w->Write<uint8_t>(opcode_base); // Field opcode_base.
1493 0 : w->Write<uint8_t>(0); // DW_LNS_COPY operands count.
1494 0 : w->Write<uint8_t>(1); // DW_LNS_ADVANCE_PC operands count.
1495 0 : w->Write<uint8_t>(1); // DW_LNS_ADVANCE_LINE operands count.
1496 0 : w->Write<uint8_t>(1); // DW_LNS_SET_FILE operands count.
1497 0 : w->Write<uint8_t>(1); // DW_LNS_SET_COLUMN operands count.
1498 0 : w->Write<uint8_t>(0); // DW_LNS_NEGATE_STMT operands count.
1499 0 : w->Write<uint8_t>(0); // Empty include_directories sequence.
1500 0 : w->WriteString(desc_->GetFilename().get()); // File name.
1501 0 : w->WriteULEB128(0); // Current directory.
1502 0 : w->WriteULEB128(0); // Unknown modification time.
1503 0 : w->WriteULEB128(0); // Unknown file size.
1504 0 : w->Write<uint8_t>(0);
1505 0 : prologue_length.set(static_cast<uint32_t>(w->position() - prologue_start));
1506 :
1507 0 : WriteExtendedOpcode(w, DW_LNE_SET_ADDRESS, sizeof(intptr_t));
1508 0 : w->Write<intptr_t>(desc_->CodeStart());
1509 0 : w->Write<uint8_t>(DW_LNS_COPY);
1510 :
1511 : intptr_t pc = 0;
1512 : intptr_t line = 1;
1513 : bool is_statement = true;
1514 :
1515 0 : std::vector<LineInfo::PCInfo>* pc_info = desc_->lineinfo()->pc_info();
1516 0 : std::sort(pc_info->begin(), pc_info->end(), &ComparePCInfo);
1517 :
1518 0 : for (size_t i = 0; i < pc_info->size(); i++) {
1519 : LineInfo::PCInfo* info = &pc_info->at(i);
1520 : DCHECK(info->pc_ >= pc);
1521 :
1522 : // Reduce bloating in the debug line table by removing duplicate line
1523 : // entries (per DWARF2 standard).
1524 0 : intptr_t new_line = desc_->GetScriptLineNumber(info->pos_);
1525 0 : if (new_line == line) {
1526 : continue;
1527 : }
1528 :
1529 : // Mark statement boundaries. For a better debugging experience, mark
1530 : // the last pc address in the function as a statement (e.g. "}"), so that
1531 : // a user can see the result of the last line executed in the function,
1532 : // should control reach the end.
1533 0 : if ((i + 1) == pc_info->size()) {
1534 0 : if (!is_statement) {
1535 0 : w->Write<uint8_t>(DW_LNS_NEGATE_STMT);
1536 : }
1537 0 : } else if (is_statement != info->is_statement_) {
1538 0 : w->Write<uint8_t>(DW_LNS_NEGATE_STMT);
1539 0 : is_statement = !is_statement;
1540 : }
1541 :
1542 : // Generate special opcodes, if possible. This results in more compact
1543 : // debug line tables. See the DWARF 2.0 standard to learn more about
1544 : // special opcodes.
1545 0 : uintptr_t pc_diff = info->pc_ - pc;
1546 0 : intptr_t line_diff = new_line - line;
1547 :
1548 : // Compute special opcode (see DWARF 2.0 standard)
1549 : intptr_t special_opcode = (line_diff - line_base) +
1550 0 : (line_range * pc_diff) + opcode_base;
1551 :
1552 : // If special_opcode is less than or equal to 255, it can be used as a
1553 : // special opcode. If line_diff is larger than the max line increment
1554 : // allowed for a special opcode, or if line_diff is less than the minimum
1555 : // line that can be added to the line register (i.e. line_base), then
1556 : // special_opcode can't be used.
1557 0 : if ((special_opcode >= opcode_base) && (special_opcode <= 255) &&
1558 0 : (line_diff <= max_line_incr) && (line_diff >= line_base)) {
1559 0 : w->Write<uint8_t>(special_opcode);
1560 : } else {
1561 0 : w->Write<uint8_t>(DW_LNS_ADVANCE_PC);
1562 0 : w->WriteSLEB128(pc_diff);
1563 0 : w->Write<uint8_t>(DW_LNS_ADVANCE_LINE);
1564 0 : w->WriteSLEB128(line_diff);
1565 0 : w->Write<uint8_t>(DW_LNS_COPY);
1566 : }
1567 :
1568 : // Increment the pc and line operands.
1569 0 : pc += pc_diff;
1570 : line += line_diff;
1571 : }
1572 : // Advance the pc to the end of the routine, since the end sequence opcode
1573 : // requires this.
1574 0 : w->Write<uint8_t>(DW_LNS_ADVANCE_PC);
1575 0 : w->WriteSLEB128(desc_->CodeSize() - pc);
1576 0 : WriteExtendedOpcode(w, DW_LNE_END_SEQUENCE, 0);
1577 0 : total_length.set(static_cast<uint32_t>(w->position() - start));
1578 0 : return true;
1579 : }
1580 :
1581 : private:
1582 0 : void WriteExtendedOpcode(Writer* w,
1583 : DWARF2ExtendedOpcode op,
1584 : size_t operands_size) {
1585 0 : w->Write<uint8_t>(0);
1586 0 : w->WriteULEB128(operands_size + 1);
1587 0 : w->Write<uint8_t>(op);
1588 0 : }
1589 :
1590 0 : static bool ComparePCInfo(const LineInfo::PCInfo& a,
1591 : const LineInfo::PCInfo& b) {
1592 0 : if (a.pc_ == b.pc_) {
1593 0 : if (a.is_statement_ != b.is_statement_) {
1594 0 : return !b.is_statement_;
1595 : }
1596 : return false;
1597 : }
1598 0 : return a.pc_ < b.pc_;
1599 : }
1600 :
1601 : CodeDescription* desc_;
1602 : };
1603 :
1604 :
1605 : #if V8_TARGET_ARCH_X64
1606 :
1607 0 : class UnwindInfoSection : public DebugSection {
1608 : public:
1609 : explicit UnwindInfoSection(CodeDescription* desc);
1610 : virtual bool WriteBodyInternal(Writer* w);
1611 :
1612 : int WriteCIE(Writer* w);
1613 : void WriteFDE(Writer* w, int);
1614 :
1615 : void WriteFDEStateOnEntry(Writer* w);
1616 : void WriteFDEStateAfterRBPPush(Writer* w);
1617 : void WriteFDEStateAfterRBPSet(Writer* w);
1618 : void WriteFDEStateAfterRBPPop(Writer* w);
1619 :
1620 : void WriteLength(Writer* w,
1621 : Writer::Slot<uint32_t>* length_slot,
1622 : int initial_position);
1623 :
1624 : private:
1625 : CodeDescription* desc_;
1626 :
1627 : // DWARF3 Specification, Table 7.23
1628 : enum CFIInstructions {
1629 : DW_CFA_ADVANCE_LOC = 0x40,
1630 : DW_CFA_OFFSET = 0x80,
1631 : DW_CFA_RESTORE = 0xC0,
1632 : DW_CFA_NOP = 0x00,
1633 : DW_CFA_SET_LOC = 0x01,
1634 : DW_CFA_ADVANCE_LOC1 = 0x02,
1635 : DW_CFA_ADVANCE_LOC2 = 0x03,
1636 : DW_CFA_ADVANCE_LOC4 = 0x04,
1637 : DW_CFA_OFFSET_EXTENDED = 0x05,
1638 : DW_CFA_RESTORE_EXTENDED = 0x06,
1639 : DW_CFA_UNDEFINED = 0x07,
1640 : DW_CFA_SAME_VALUE = 0x08,
1641 : DW_CFA_REGISTER = 0x09,
1642 : DW_CFA_REMEMBER_STATE = 0x0A,
1643 : DW_CFA_RESTORE_STATE = 0x0B,
1644 : DW_CFA_DEF_CFA = 0x0C,
1645 : DW_CFA_DEF_CFA_REGISTER = 0x0D,
1646 : DW_CFA_DEF_CFA_OFFSET = 0x0E,
1647 :
1648 : DW_CFA_DEF_CFA_EXPRESSION = 0x0F,
1649 : DW_CFA_EXPRESSION = 0x10,
1650 : DW_CFA_OFFSET_EXTENDED_SF = 0x11,
1651 : DW_CFA_DEF_CFA_SF = 0x12,
1652 : DW_CFA_DEF_CFA_OFFSET_SF = 0x13,
1653 : DW_CFA_VAL_OFFSET = 0x14,
1654 : DW_CFA_VAL_OFFSET_SF = 0x15,
1655 : DW_CFA_VAL_EXPRESSION = 0x16
1656 : };
1657 :
1658 : // System V ABI, AMD64 Supplement, Version 0.99.5, Figure 3.36
1659 : enum RegisterMapping {
1660 : // Only the relevant ones have been added to reduce clutter.
1661 : AMD64_RBP = 6,
1662 : AMD64_RSP = 7,
1663 : AMD64_RA = 16
1664 : };
1665 :
1666 : enum CFIConstants {
1667 : CIE_ID = 0,
1668 : CIE_VERSION = 1,
1669 : CODE_ALIGN_FACTOR = 1,
1670 : DATA_ALIGN_FACTOR = 1,
1671 : RETURN_ADDRESS_REGISTER = AMD64_RA
1672 : };
1673 : };
1674 :
1675 :
1676 0 : void UnwindInfoSection::WriteLength(Writer* w,
1677 : Writer::Slot<uint32_t>* length_slot,
1678 : int initial_position) {
1679 0 : uint32_t align = (w->position() - initial_position) % kPointerSize;
1680 :
1681 0 : if (align != 0) {
1682 0 : for (uint32_t i = 0; i < (kPointerSize - align); i++) {
1683 0 : w->Write<uint8_t>(DW_CFA_NOP);
1684 : }
1685 : }
1686 :
1687 : DCHECK_EQ((w->position() - initial_position) % kPointerSize, 0);
1688 0 : length_slot->set(static_cast<uint32_t>(w->position() - initial_position));
1689 0 : }
1690 :
1691 :
1692 0 : UnwindInfoSection::UnwindInfoSection(CodeDescription* desc)
1693 : #ifdef __ELF
1694 : : ELFSection(".eh_frame", TYPE_X86_64_UNWIND, 1),
1695 : #else
1696 : : MachOSection("__eh_frame", "__TEXT", sizeof(uintptr_t),
1697 : MachOSection::S_REGULAR),
1698 : #endif
1699 0 : desc_(desc) { }
1700 :
1701 0 : int UnwindInfoSection::WriteCIE(Writer* w) {
1702 0 : Writer::Slot<uint32_t> cie_length_slot = w->CreateSlotHere<uint32_t>();
1703 : uint32_t cie_position = static_cast<uint32_t>(w->position());
1704 :
1705 : // Write out the CIE header. Currently no 'common instructions' are
1706 : // emitted onto the CIE; every FDE has its own set of instructions.
1707 :
1708 0 : w->Write<uint32_t>(CIE_ID);
1709 0 : w->Write<uint8_t>(CIE_VERSION);
1710 0 : w->Write<uint8_t>(0); // Null augmentation string.
1711 0 : w->WriteSLEB128(CODE_ALIGN_FACTOR);
1712 0 : w->WriteSLEB128(DATA_ALIGN_FACTOR);
1713 0 : w->Write<uint8_t>(RETURN_ADDRESS_REGISTER);
1714 :
1715 0 : WriteLength(w, &cie_length_slot, cie_position);
1716 :
1717 0 : return cie_position;
1718 : }
1719 :
1720 :
1721 0 : void UnwindInfoSection::WriteFDE(Writer* w, int cie_position) {
1722 : // The only FDE for this function. The CFA is the current RBP.
1723 0 : Writer::Slot<uint32_t> fde_length_slot = w->CreateSlotHere<uint32_t>();
1724 0 : int fde_position = static_cast<uint32_t>(w->position());
1725 0 : w->Write<int32_t>(fde_position - cie_position + 4);
1726 :
1727 0 : w->Write<uintptr_t>(desc_->CodeStart());
1728 0 : w->Write<uintptr_t>(desc_->CodeSize());
1729 :
1730 0 : WriteFDEStateOnEntry(w);
1731 0 : WriteFDEStateAfterRBPPush(w);
1732 0 : WriteFDEStateAfterRBPSet(w);
1733 0 : WriteFDEStateAfterRBPPop(w);
1734 :
1735 0 : WriteLength(w, &fde_length_slot, fde_position);
1736 0 : }
1737 :
1738 :
1739 0 : void UnwindInfoSection::WriteFDEStateOnEntry(Writer* w) {
1740 : // The first state, just after the control has been transferred to the the
1741 : // function.
1742 :
1743 : // RBP for this function will be the value of RSP after pushing the RBP
1744 : // for the previous function. The previous RBP has not been pushed yet.
1745 0 : w->Write<uint8_t>(DW_CFA_DEF_CFA_SF);
1746 0 : w->WriteULEB128(AMD64_RSP);
1747 0 : w->WriteSLEB128(-kPointerSize);
1748 :
1749 : // The RA is stored at location CFA + kCallerPCOffset. This is an invariant,
1750 : // and hence omitted from the next states.
1751 0 : w->Write<uint8_t>(DW_CFA_OFFSET_EXTENDED);
1752 0 : w->WriteULEB128(AMD64_RA);
1753 0 : w->WriteSLEB128(StandardFrameConstants::kCallerPCOffset);
1754 :
1755 : // The RBP of the previous function is still in RBP.
1756 0 : w->Write<uint8_t>(DW_CFA_SAME_VALUE);
1757 0 : w->WriteULEB128(AMD64_RBP);
1758 :
1759 : // Last location described by this entry.
1760 0 : w->Write<uint8_t>(DW_CFA_SET_LOC);
1761 : w->Write<uint64_t>(
1762 0 : desc_->GetStackStateStartAddress(CodeDescription::POST_RBP_PUSH));
1763 0 : }
1764 :
1765 :
1766 0 : void UnwindInfoSection::WriteFDEStateAfterRBPPush(Writer* w) {
1767 : // The second state, just after RBP has been pushed.
1768 :
1769 : // RBP / CFA for this function is now the current RSP, so just set the
1770 : // offset from the previous rule (from -8) to 0.
1771 0 : w->Write<uint8_t>(DW_CFA_DEF_CFA_OFFSET);
1772 0 : w->WriteULEB128(0);
1773 :
1774 : // The previous RBP is stored at CFA + kCallerFPOffset. This is an invariant
1775 : // in this and the next state, and hence omitted in the next state.
1776 0 : w->Write<uint8_t>(DW_CFA_OFFSET_EXTENDED);
1777 0 : w->WriteULEB128(AMD64_RBP);
1778 0 : w->WriteSLEB128(StandardFrameConstants::kCallerFPOffset);
1779 :
1780 : // Last location described by this entry.
1781 0 : w->Write<uint8_t>(DW_CFA_SET_LOC);
1782 : w->Write<uint64_t>(
1783 0 : desc_->GetStackStateStartAddress(CodeDescription::POST_RBP_SET));
1784 0 : }
1785 :
1786 :
1787 0 : void UnwindInfoSection::WriteFDEStateAfterRBPSet(Writer* w) {
1788 : // The third state, after the RBP has been set.
1789 :
1790 : // The CFA can now directly be set to RBP.
1791 0 : w->Write<uint8_t>(DW_CFA_DEF_CFA);
1792 0 : w->WriteULEB128(AMD64_RBP);
1793 0 : w->WriteULEB128(0);
1794 :
1795 : // Last location described by this entry.
1796 0 : w->Write<uint8_t>(DW_CFA_SET_LOC);
1797 : w->Write<uint64_t>(
1798 0 : desc_->GetStackStateStartAddress(CodeDescription::POST_RBP_POP));
1799 0 : }
1800 :
1801 :
1802 0 : void UnwindInfoSection::WriteFDEStateAfterRBPPop(Writer* w) {
1803 : // The fourth (final) state. The RBP has been popped (just before issuing a
1804 : // return).
1805 :
1806 : // The CFA can is now calculated in the same way as in the first state.
1807 0 : w->Write<uint8_t>(DW_CFA_DEF_CFA_SF);
1808 0 : w->WriteULEB128(AMD64_RSP);
1809 0 : w->WriteSLEB128(-kPointerSize);
1810 :
1811 : // The RBP
1812 0 : w->Write<uint8_t>(DW_CFA_OFFSET_EXTENDED);
1813 0 : w->WriteULEB128(AMD64_RBP);
1814 0 : w->WriteSLEB128(StandardFrameConstants::kCallerFPOffset);
1815 :
1816 : // Last location described by this entry.
1817 0 : w->Write<uint8_t>(DW_CFA_SET_LOC);
1818 0 : w->Write<uint64_t>(desc_->CodeEnd());
1819 0 : }
1820 :
1821 :
1822 0 : bool UnwindInfoSection::WriteBodyInternal(Writer* w) {
1823 0 : uint32_t cie_position = WriteCIE(w);
1824 0 : WriteFDE(w, cie_position);
1825 0 : return true;
1826 : }
1827 :
1828 :
1829 : #endif // V8_TARGET_ARCH_X64
1830 :
1831 0 : static void CreateDWARFSections(CodeDescription* desc,
1832 : Zone* zone,
1833 : DebugObject* obj) {
1834 0 : if (desc->IsLineInfoAvailable()) {
1835 0 : obj->AddSection(new(zone) DebugInfoSection(desc));
1836 0 : obj->AddSection(new(zone) DebugAbbrevSection(desc));
1837 0 : obj->AddSection(new(zone) DebugLineSection(desc));
1838 : }
1839 : #if V8_TARGET_ARCH_X64
1840 0 : obj->AddSection(new(zone) UnwindInfoSection(desc));
1841 : #endif
1842 0 : }
1843 :
1844 :
1845 : // -------------------------------------------------------------------
1846 : // Binary GDB JIT Interface as described in
1847 : // http://sourceware.org/gdb/onlinedocs/gdb/Declarations.html
1848 : extern "C" {
1849 : typedef enum {
1850 : JIT_NOACTION = 0,
1851 : JIT_REGISTER_FN,
1852 : JIT_UNREGISTER_FN
1853 : } JITAction;
1854 :
1855 : struct JITCodeEntry {
1856 : JITCodeEntry* next_;
1857 : JITCodeEntry* prev_;
1858 : Address symfile_addr_;
1859 : uint64_t symfile_size_;
1860 : };
1861 :
1862 : struct JITDescriptor {
1863 : uint32_t version_;
1864 : uint32_t action_flag_;
1865 : JITCodeEntry* relevant_entry_;
1866 : JITCodeEntry* first_entry_;
1867 : };
1868 :
1869 : // GDB will place breakpoint into this function.
1870 : // To prevent GCC from inlining or removing it we place noinline attribute
1871 : // and inline assembler statement inside.
1872 0 : void __attribute__((noinline)) __jit_debug_register_code() {
1873 0 : __asm__("");
1874 0 : }
1875 :
1876 : // GDB will inspect contents of this descriptor.
1877 : // Static initialization is necessary to prevent GDB from seeing
1878 : // uninitialized descriptor.
1879 : JITDescriptor __jit_debug_descriptor = { 1, 0, 0, 0 };
1880 :
1881 : #ifdef OBJECT_PRINT
1882 : void __gdb_print_v8_object(Object* object) {
1883 : OFStream os(stdout);
1884 : object->Print(os);
1885 : os << std::flush;
1886 : }
1887 : #endif
1888 : }
1889 :
1890 :
1891 0 : static JITCodeEntry* CreateCodeEntry(Address symfile_addr,
1892 : uintptr_t symfile_size) {
1893 : JITCodeEntry* entry = static_cast<JITCodeEntry*>(
1894 0 : malloc(sizeof(JITCodeEntry) + symfile_size));
1895 :
1896 0 : entry->symfile_addr_ = reinterpret_cast<Address>(entry + 1);
1897 0 : entry->symfile_size_ = symfile_size;
1898 : MemCopy(entry->symfile_addr_, symfile_addr, symfile_size);
1899 :
1900 0 : entry->prev_ = entry->next_ = nullptr;
1901 :
1902 0 : return entry;
1903 : }
1904 :
1905 :
1906 : static void DestroyCodeEntry(JITCodeEntry* entry) {
1907 0 : free(entry);
1908 : }
1909 :
1910 :
1911 0 : static void RegisterCodeEntry(JITCodeEntry* entry) {
1912 0 : entry->next_ = __jit_debug_descriptor.first_entry_;
1913 0 : if (entry->next_ != nullptr) entry->next_->prev_ = entry;
1914 : __jit_debug_descriptor.first_entry_ =
1915 0 : __jit_debug_descriptor.relevant_entry_ = entry;
1916 :
1917 0 : __jit_debug_descriptor.action_flag_ = JIT_REGISTER_FN;
1918 0 : __jit_debug_register_code();
1919 0 : }
1920 :
1921 :
1922 0 : static void UnregisterCodeEntry(JITCodeEntry* entry) {
1923 0 : if (entry->prev_ != nullptr) {
1924 0 : entry->prev_->next_ = entry->next_;
1925 : } else {
1926 0 : __jit_debug_descriptor.first_entry_ = entry->next_;
1927 : }
1928 :
1929 0 : if (entry->next_ != nullptr) {
1930 0 : entry->next_->prev_ = entry->prev_;
1931 : }
1932 :
1933 0 : __jit_debug_descriptor.relevant_entry_ = entry;
1934 0 : __jit_debug_descriptor.action_flag_ = JIT_UNREGISTER_FN;
1935 0 : __jit_debug_register_code();
1936 0 : }
1937 :
1938 :
1939 0 : static JITCodeEntry* CreateELFObject(CodeDescription* desc, Isolate* isolate) {
1940 : #ifdef __MACH_O
1941 : Zone zone(isolate->allocator(), ZONE_NAME);
1942 : MachO mach_o(&zone);
1943 : Writer w(&mach_o);
1944 :
1945 : mach_o.AddSection(new(&zone) MachOTextSection(kCodeAlignment,
1946 : desc->CodeStart(),
1947 : desc->CodeSize()));
1948 :
1949 : CreateDWARFSections(desc, &zone, &mach_o);
1950 :
1951 : mach_o.Write(&w, desc->CodeStart(), desc->CodeSize());
1952 : #else
1953 0 : Zone zone(isolate->allocator(), ZONE_NAME);
1954 0 : ELF elf(&zone);
1955 : Writer w(&elf);
1956 :
1957 : int text_section_index = elf.AddSection(
1958 : new(&zone) FullHeaderELFSection(
1959 : ".text",
1960 : ELFSection::TYPE_NOBITS,
1961 : kCodeAlignment,
1962 : desc->CodeStart(),
1963 : 0,
1964 : desc->CodeSize(),
1965 0 : ELFSection::FLAG_ALLOC | ELFSection::FLAG_EXEC));
1966 :
1967 0 : CreateSymbolsTable(desc, &zone, &elf, text_section_index);
1968 :
1969 0 : CreateDWARFSections(desc, &zone, &elf);
1970 :
1971 0 : elf.Write(&w);
1972 : #endif
1973 :
1974 0 : return CreateCodeEntry(w.buffer(), w.position());
1975 : }
1976 :
1977 :
1978 : struct AddressRange {
1979 : Address start;
1980 : Address end;
1981 : };
1982 :
1983 : struct SplayTreeConfig {
1984 : typedef AddressRange Key;
1985 : typedef JITCodeEntry* Value;
1986 : static const AddressRange kNoKey;
1987 : static Value NoValue() { return nullptr; }
1988 : static int Compare(const AddressRange& a, const AddressRange& b) {
1989 : // ptrdiff_t probably doesn't fit in an int.
1990 0 : if (a.start < b.start) return -1;
1991 0 : if (a.start == b.start) return 0;
1992 : return 1;
1993 : }
1994 : };
1995 :
1996 : const AddressRange SplayTreeConfig::kNoKey = {0, 0};
1997 : typedef SplayTree<SplayTreeConfig> CodeMap;
1998 :
1999 0 : static CodeMap* GetCodeMap() {
2000 : static CodeMap* code_map = nullptr;
2001 0 : if (code_map == nullptr) code_map = new CodeMap();
2002 0 : return code_map;
2003 : }
2004 :
2005 :
2006 : static uint32_t HashCodeAddress(Address addr) {
2007 : static const uintptr_t kGoldenRatio = 2654435761u;
2008 0 : uintptr_t offset = OffsetFrom(addr);
2009 0 : return static_cast<uint32_t>((offset >> kCodeAlignmentBits) * kGoldenRatio);
2010 : }
2011 :
2012 0 : static base::HashMap* GetLineMap() {
2013 : static base::HashMap* line_map = nullptr;
2014 0 : if (line_map == nullptr) {
2015 0 : line_map = new base::HashMap();
2016 : }
2017 0 : return line_map;
2018 : }
2019 :
2020 :
2021 0 : static void PutLineInfo(Address addr, LineInfo* info) {
2022 0 : base::HashMap* line_map = GetLineMap();
2023 : base::HashMap::Entry* e =
2024 0 : line_map->LookupOrInsert(addr, HashCodeAddress(addr));
2025 0 : if (e->value != nullptr) delete static_cast<LineInfo*>(e->value);
2026 0 : e->value = info;
2027 0 : }
2028 :
2029 :
2030 0 : static LineInfo* GetLineInfo(Address addr) {
2031 0 : void* value = GetLineMap()->Remove(addr, HashCodeAddress(addr));
2032 0 : return static_cast<LineInfo*>(value);
2033 : }
2034 :
2035 :
2036 0 : static void AddUnwindInfo(CodeDescription* desc) {
2037 : #if V8_TARGET_ARCH_X64
2038 0 : if (desc->is_function()) {
2039 : // To avoid propagating unwinding information through
2040 : // compilation pipeline we use an approximation.
2041 : // For most use cases this should not affect usability.
2042 : static const int kFramePointerPushOffset = 1;
2043 : static const int kFramePointerSetOffset = 4;
2044 : static const int kFramePointerPopOffset = -3;
2045 :
2046 : uintptr_t frame_pointer_push_address =
2047 0 : desc->CodeStart() + kFramePointerPushOffset;
2048 :
2049 : uintptr_t frame_pointer_set_address =
2050 0 : desc->CodeStart() + kFramePointerSetOffset;
2051 :
2052 : uintptr_t frame_pointer_pop_address =
2053 0 : desc->CodeEnd() + kFramePointerPopOffset;
2054 :
2055 : desc->SetStackStateStartAddress(CodeDescription::POST_RBP_PUSH,
2056 : frame_pointer_push_address);
2057 : desc->SetStackStateStartAddress(CodeDescription::POST_RBP_SET,
2058 : frame_pointer_set_address);
2059 : desc->SetStackStateStartAddress(CodeDescription::POST_RBP_POP,
2060 : frame_pointer_pop_address);
2061 : } else {
2062 : desc->SetStackStateStartAddress(CodeDescription::POST_RBP_PUSH,
2063 : desc->CodeStart());
2064 : desc->SetStackStateStartAddress(CodeDescription::POST_RBP_SET,
2065 : desc->CodeStart());
2066 : desc->SetStackStateStartAddress(CodeDescription::POST_RBP_POP,
2067 : desc->CodeEnd());
2068 : }
2069 : #endif // V8_TARGET_ARCH_X64
2070 0 : }
2071 :
2072 :
2073 : static base::LazyMutex mutex = LAZY_MUTEX_INITIALIZER;
2074 :
2075 :
2076 : // Remove entries from the splay tree that intersect the given address range,
2077 : // and deregister them from GDB.
2078 0 : static void RemoveJITCodeEntries(CodeMap* map, const AddressRange& range) {
2079 : DCHECK(range.start < range.end);
2080 : CodeMap::Locator cur;
2081 0 : if (map->FindGreatestLessThan(range, &cur) || map->FindLeast(&cur)) {
2082 : // Skip entries that are entirely less than the range of interest.
2083 0 : while (cur.key().end <= range.start) {
2084 : // CodeMap::FindLeastGreaterThan succeeds for entries whose key is greater
2085 : // than _or equal to_ the given key, so we have to advance our key to get
2086 : // the next one.
2087 : AddressRange new_key;
2088 0 : new_key.start = cur.key().end;
2089 0 : new_key.end = 0;
2090 0 : if (!map->FindLeastGreaterThan(new_key, &cur)) return;
2091 : }
2092 : // Evict intersecting ranges.
2093 0 : while (cur.key().start < range.end) {
2094 0 : AddressRange old_range = cur.key();
2095 0 : JITCodeEntry* old_entry = cur.value();
2096 :
2097 0 : UnregisterCodeEntry(old_entry);
2098 : DestroyCodeEntry(old_entry);
2099 :
2100 0 : CHECK(map->Remove(old_range));
2101 0 : if (!map->FindLeastGreaterThan(old_range, &cur)) return;
2102 : }
2103 : }
2104 : }
2105 :
2106 :
2107 : // Insert the entry into the splay tree and register it with GDB.
2108 0 : static void AddJITCodeEntry(CodeMap* map, const AddressRange& range,
2109 : JITCodeEntry* entry, bool dump_if_enabled,
2110 : const char* name_hint) {
2111 : #if defined(DEBUG) && !V8_OS_WIN
2112 : static int file_num = 0;
2113 : if (FLAG_gdbjit_dump && dump_if_enabled) {
2114 : static const int kMaxFileNameSize = 64;
2115 : char file_name[64];
2116 :
2117 : SNPrintF(Vector<char>(file_name, kMaxFileNameSize), "/tmp/elfdump%s%d.o",
2118 : (name_hint != nullptr) ? name_hint : "", file_num++);
2119 : WriteBytes(file_name, entry->symfile_addr_,
2120 : static_cast<int>(entry->symfile_size_));
2121 : }
2122 : #endif
2123 :
2124 : CodeMap::Locator cur;
2125 0 : CHECK(map->Insert(range, &cur));
2126 : cur.set_value(entry);
2127 :
2128 0 : RegisterCodeEntry(entry);
2129 0 : }
2130 :
2131 :
2132 0 : static void AddCode(const char* name, Code* code, SharedFunctionInfo* shared,
2133 : LineInfo* lineinfo) {
2134 : DisallowHeapAllocation no_gc;
2135 :
2136 0 : CodeMap* code_map = GetCodeMap();
2137 : AddressRange range;
2138 0 : range.start = code->address();
2139 0 : range.end = code->address() + code->CodeSize();
2140 0 : RemoveJITCodeEntries(code_map, range);
2141 :
2142 : CodeDescription code_desc(name, code, shared, lineinfo);
2143 :
2144 0 : if (!FLAG_gdbjit_full && !code_desc.IsLineInfoAvailable()) {
2145 0 : delete lineinfo;
2146 0 : return;
2147 : }
2148 :
2149 0 : AddUnwindInfo(&code_desc);
2150 : Isolate* isolate = code->GetIsolate();
2151 0 : JITCodeEntry* entry = CreateELFObject(&code_desc, isolate);
2152 :
2153 0 : delete lineinfo;
2154 :
2155 : const char* name_hint = nullptr;
2156 : bool should_dump = false;
2157 : if (FLAG_gdbjit_dump) {
2158 : if (strlen(FLAG_gdbjit_dump_filter) == 0) {
2159 : name_hint = name;
2160 : should_dump = true;
2161 : } else if (name != nullptr) {
2162 : name_hint = strstr(name, FLAG_gdbjit_dump_filter);
2163 : should_dump = (name_hint != nullptr);
2164 : }
2165 : }
2166 0 : AddJITCodeEntry(code_map, range, entry, should_dump, name_hint);
2167 : }
2168 :
2169 :
2170 0 : void EventHandler(const v8::JitCodeEvent* event) {
2171 0 : if (!FLAG_gdbjit) return;
2172 : base::LockGuard<base::Mutex> lock_guard(mutex.Pointer());
2173 0 : switch (event->type) {
2174 : case v8::JitCodeEvent::CODE_ADDED: {
2175 0 : Address addr = reinterpret_cast<Address>(event->code_start);
2176 0 : Code* code = Code::GetCodeFromTargetAddress(addr);
2177 0 : LineInfo* lineinfo = GetLineInfo(addr);
2178 : EmbeddedVector<char, 256> buffer;
2179 : StringBuilder builder(buffer.start(), buffer.length());
2180 0 : builder.AddSubstring(event->name.str, static_cast<int>(event->name.len));
2181 : // It's called UnboundScript in the API but it's a SharedFunctionInfo.
2182 : SharedFunctionInfo* shared = event->script.IsEmpty()
2183 : ? nullptr
2184 0 : : *Utils::OpenHandle(*event->script);
2185 0 : AddCode(builder.Finalize(), code, shared, lineinfo);
2186 : break;
2187 : }
2188 : case v8::JitCodeEvent::CODE_MOVED:
2189 : // Enabling the GDB JIT interface should disable code compaction.
2190 0 : UNREACHABLE();
2191 : break;
2192 : case v8::JitCodeEvent::CODE_REMOVED:
2193 : // Do nothing. Instead, adding code causes eviction of any entry whose
2194 : // address range intersects the address range of the added code.
2195 : break;
2196 : case v8::JitCodeEvent::CODE_ADD_LINE_POS_INFO: {
2197 0 : LineInfo* line_info = reinterpret_cast<LineInfo*>(event->user_data);
2198 : line_info->SetPosition(static_cast<intptr_t>(event->line_info.offset),
2199 : static_cast<int>(event->line_info.pos),
2200 : event->line_info.position_type ==
2201 0 : v8::JitCodeEvent::STATEMENT_POSITION);
2202 : break;
2203 : }
2204 : case v8::JitCodeEvent::CODE_START_LINE_INFO_RECORDING: {
2205 : v8::JitCodeEvent* mutable_event = const_cast<v8::JitCodeEvent*>(event);
2206 0 : mutable_event->user_data = new LineInfo();
2207 0 : break;
2208 : }
2209 : case v8::JitCodeEvent::CODE_END_LINE_INFO_RECORDING: {
2210 0 : LineInfo* line_info = reinterpret_cast<LineInfo*>(event->user_data);
2211 0 : PutLineInfo(reinterpret_cast<Address>(event->code_start), line_info);
2212 0 : break;
2213 : }
2214 : }
2215 : }
2216 : #endif
2217 : } // namespace GDBJITInterface
2218 : } // namespace internal
2219 : } // namespace v8
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