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-inl.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/objects.h"
18 : #include "src/ostreams.h"
19 : #include "src/snapshot/natives.h"
20 : #include "src/splay-tree-inl.h"
21 : #include "src/zone/zone-chunk-list.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 {
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() = default;
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 : ~MachOSection() override = default;
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 { INDEX_ABSOLUTE = 0xFFF1 };
312 :
313 : ELFSection(const char* name, Type type, uintptr_t align)
314 0 : : name_(name), type_(type), align_(align) { }
315 :
316 0 : ~ELFSection() override = default;
317 :
318 : void PopulateHeader(Writer::Slot<Header> header, ELFStringTable* strtab);
319 :
320 0 : void WriteBody(Writer::Slot<Header> header, Writer* w) override {
321 : uintptr_t start = w->position();
322 0 : if (WriteBodyInternal(w)) {
323 : uintptr_t end = w->position();
324 0 : header->offset = start;
325 0 : header->size = end - start;
326 : }
327 0 : }
328 :
329 0 : bool WriteBodyInternal(Writer* w) override { return false; }
330 :
331 : uint16_t index() const { return index_; }
332 0 : void set_index(uint16_t index) { index_ = index; }
333 :
334 : protected:
335 0 : virtual void PopulateHeader(Writer::Slot<Header> header) {
336 0 : header->flags = 0;
337 0 : header->address = 0;
338 0 : header->offset = 0;
339 0 : header->size = 0;
340 0 : header->link = 0;
341 0 : header->info = 0;
342 0 : header->entry_size = 0;
343 0 : }
344 :
345 : private:
346 : const char* name_;
347 : Type type_;
348 : uintptr_t align_;
349 : uint16_t index_;
350 : };
351 : #endif // defined(__ELF)
352 :
353 :
354 : #if defined(__MACH_O)
355 : class MachOTextSection : public MachOSection {
356 : public:
357 : MachOTextSection(uint32_t align, uintptr_t addr, uintptr_t size)
358 : : MachOSection("__text", "__TEXT", align,
359 : MachOSection::S_REGULAR |
360 : MachOSection::S_ATTR_SOME_INSTRUCTIONS |
361 : MachOSection::S_ATTR_PURE_INSTRUCTIONS),
362 : addr_(addr),
363 : size_(size) {}
364 :
365 : protected:
366 : virtual void PopulateHeader(Writer::Slot<Header> header) {
367 : MachOSection::PopulateHeader(header);
368 : header->addr = addr_;
369 : header->size = size_;
370 : }
371 :
372 : private:
373 : uintptr_t addr_;
374 : uintptr_t size_;
375 : };
376 : #endif // defined(__MACH_O)
377 :
378 :
379 : #if defined(__ELF)
380 0 : class FullHeaderELFSection : public ELFSection {
381 : public:
382 : FullHeaderELFSection(const char* name,
383 : Type type,
384 : uintptr_t align,
385 : uintptr_t addr,
386 : uintptr_t offset,
387 : uintptr_t size,
388 : uintptr_t flags)
389 : : ELFSection(name, type, align),
390 : addr_(addr),
391 : offset_(offset),
392 : size_(size),
393 0 : flags_(flags) { }
394 :
395 : protected:
396 0 : void PopulateHeader(Writer::Slot<Header> header) override {
397 0 : ELFSection::PopulateHeader(header);
398 0 : header->address = addr_;
399 0 : header->offset = offset_;
400 0 : header->size = size_;
401 0 : header->flags = flags_;
402 0 : }
403 :
404 : private:
405 : uintptr_t addr_;
406 : uintptr_t offset_;
407 : uintptr_t size_;
408 : uintptr_t flags_;
409 : };
410 :
411 :
412 0 : class ELFStringTable : public ELFSection {
413 : public:
414 : explicit ELFStringTable(const char* name)
415 : : ELFSection(name, TYPE_STRTAB, 1),
416 : writer_(nullptr),
417 : offset_(0),
418 0 : size_(0) {}
419 :
420 : uintptr_t Add(const char* str) {
421 0 : if (*str == '\0') return 0;
422 :
423 0 : uintptr_t offset = size_;
424 0 : WriteString(str);
425 : return offset;
426 : }
427 :
428 : void AttachWriter(Writer* w) {
429 0 : writer_ = w;
430 0 : offset_ = writer_->position();
431 :
432 : // First entry in the string table should be an empty string.
433 0 : WriteString("");
434 : }
435 :
436 0 : void DetachWriter() { writer_ = nullptr; }
437 :
438 0 : void WriteBody(Writer::Slot<Header> header, Writer* w) override {
439 : DCHECK_NULL(writer_);
440 0 : header->offset = offset_;
441 0 : header->size = size_;
442 0 : }
443 :
444 : private:
445 0 : void WriteString(const char* str) {
446 : uintptr_t written = 0;
447 0 : do {
448 0 : writer_->Write(*str);
449 0 : written++;
450 : } while (*str++);
451 0 : size_ += written;
452 0 : }
453 :
454 : Writer* writer_;
455 :
456 : uintptr_t offset_;
457 : uintptr_t size_;
458 : };
459 :
460 :
461 0 : void ELFSection::PopulateHeader(Writer::Slot<ELFSection::Header> header,
462 : ELFStringTable* strtab) {
463 0 : header->name = static_cast<uint32_t>(strtab->Add(name_));
464 0 : header->type = type_;
465 0 : header->alignment = align_;
466 0 : PopulateHeader(header);
467 0 : }
468 : #endif // defined(__ELF)
469 :
470 :
471 : #if defined(__MACH_O)
472 : class MachO {
473 : public:
474 : explicit MachO(Zone* zone) : sections_(zone) {}
475 :
476 : size_t AddSection(MachOSection* section) {
477 : sections_.push_back(section);
478 : return sections_.size() - 1;
479 : }
480 :
481 : void Write(Writer* w, uintptr_t code_start, uintptr_t code_size) {
482 : Writer::Slot<MachOHeader> header = WriteHeader(w);
483 : uintptr_t load_command_start = w->position();
484 : Writer::Slot<MachOSegmentCommand> cmd = WriteSegmentCommand(w,
485 : code_start,
486 : code_size);
487 : WriteSections(w, cmd, header, load_command_start);
488 : }
489 :
490 : private:
491 : struct MachOHeader {
492 : uint32_t magic;
493 : uint32_t cputype;
494 : uint32_t cpusubtype;
495 : uint32_t filetype;
496 : uint32_t ncmds;
497 : uint32_t sizeofcmds;
498 : uint32_t flags;
499 : #if V8_TARGET_ARCH_X64
500 : uint32_t reserved;
501 : #endif
502 : };
503 :
504 : struct MachOSegmentCommand {
505 : uint32_t cmd;
506 : uint32_t cmdsize;
507 : char segname[16];
508 : #if V8_TARGET_ARCH_IA32
509 : uint32_t vmaddr;
510 : uint32_t vmsize;
511 : uint32_t fileoff;
512 : uint32_t filesize;
513 : #else
514 : uint64_t vmaddr;
515 : uint64_t vmsize;
516 : uint64_t fileoff;
517 : uint64_t filesize;
518 : #endif
519 : uint32_t maxprot;
520 : uint32_t initprot;
521 : uint32_t nsects;
522 : uint32_t flags;
523 : };
524 :
525 : enum MachOLoadCommandCmd {
526 : LC_SEGMENT_32 = 0x00000001u,
527 : LC_SEGMENT_64 = 0x00000019u
528 : };
529 :
530 :
531 : Writer::Slot<MachOHeader> WriteHeader(Writer* w) {
532 : DCHECK_EQ(w->position(), 0);
533 : Writer::Slot<MachOHeader> header = w->CreateSlotHere<MachOHeader>();
534 : #if V8_TARGET_ARCH_IA32
535 : header->magic = 0xFEEDFACEu;
536 : header->cputype = 7; // i386
537 : header->cpusubtype = 3; // CPU_SUBTYPE_I386_ALL
538 : #elif V8_TARGET_ARCH_X64
539 : header->magic = 0xFEEDFACFu;
540 : header->cputype = 7 | 0x01000000; // i386 | 64-bit ABI
541 : header->cpusubtype = 3; // CPU_SUBTYPE_I386_ALL
542 : header->reserved = 0;
543 : #else
544 : #error Unsupported target architecture.
545 : #endif
546 : header->filetype = 0x1; // MH_OBJECT
547 : header->ncmds = 1;
548 : header->sizeofcmds = 0;
549 : header->flags = 0;
550 : return header;
551 : }
552 :
553 :
554 : Writer::Slot<MachOSegmentCommand> WriteSegmentCommand(Writer* w,
555 : uintptr_t code_start,
556 : uintptr_t code_size) {
557 : Writer::Slot<MachOSegmentCommand> cmd =
558 : w->CreateSlotHere<MachOSegmentCommand>();
559 : #if V8_TARGET_ARCH_IA32
560 : cmd->cmd = LC_SEGMENT_32;
561 : #else
562 : cmd->cmd = LC_SEGMENT_64;
563 : #endif
564 : cmd->vmaddr = code_start;
565 : cmd->vmsize = code_size;
566 : cmd->fileoff = 0;
567 : cmd->filesize = 0;
568 : cmd->maxprot = 7;
569 : cmd->initprot = 7;
570 : cmd->flags = 0;
571 : cmd->nsects = static_cast<uint32_t>(sections_.size());
572 : memset(cmd->segname, 0, 16);
573 : cmd->cmdsize = sizeof(MachOSegmentCommand) + sizeof(MachOSection::Header) *
574 : cmd->nsects;
575 : return cmd;
576 : }
577 :
578 :
579 : void WriteSections(Writer* w,
580 : Writer::Slot<MachOSegmentCommand> cmd,
581 : Writer::Slot<MachOHeader> header,
582 : uintptr_t load_command_start) {
583 : Writer::Slot<MachOSection::Header> headers =
584 : w->CreateSlotsHere<MachOSection::Header>(
585 : static_cast<uint32_t>(sections_.size()));
586 : cmd->fileoff = w->position();
587 : header->sizeofcmds =
588 : static_cast<uint32_t>(w->position() - load_command_start);
589 : uint32_t index = 0;
590 : for (MachOSection* section : sections_) {
591 : section->PopulateHeader(headers.at(index));
592 : section->WriteBody(headers.at(index), w);
593 : index++;
594 : }
595 : cmd->filesize = w->position() - (uintptr_t)cmd->fileoff;
596 : }
597 :
598 : ZoneChunkList<MachOSection*> sections_;
599 : };
600 : #endif // defined(__MACH_O)
601 :
602 :
603 : #if defined(__ELF)
604 : class ELF {
605 : public:
606 0 : explicit ELF(Zone* zone) : sections_(zone) {
607 0 : sections_.push_back(new (zone) ELFSection("", ELFSection::TYPE_NULL, 0));
608 0 : sections_.push_back(new (zone) ELFStringTable(".shstrtab"));
609 0 : }
610 :
611 0 : void Write(Writer* w) {
612 0 : WriteHeader(w);
613 0 : WriteSectionTable(w);
614 0 : WriteSections(w);
615 0 : }
616 :
617 0 : ELFSection* SectionAt(uint32_t index) { return *sections_.Find(index); }
618 :
619 : size_t AddSection(ELFSection* section) {
620 0 : sections_.push_back(section);
621 0 : section->set_index(sections_.size() - 1);
622 0 : return sections_.size() - 1;
623 : }
624 :
625 : private:
626 : struct ELFHeader {
627 : uint8_t ident[16];
628 : uint16_t type;
629 : uint16_t machine;
630 : uint32_t version;
631 : uintptr_t entry;
632 : uintptr_t pht_offset;
633 : uintptr_t sht_offset;
634 : uint32_t flags;
635 : uint16_t header_size;
636 : uint16_t pht_entry_size;
637 : uint16_t pht_entry_num;
638 : uint16_t sht_entry_size;
639 : uint16_t sht_entry_num;
640 : uint16_t sht_strtab_index;
641 : };
642 :
643 :
644 0 : void WriteHeader(Writer* w) {
645 : DCHECK_EQ(w->position(), 0);
646 : Writer::Slot<ELFHeader> header = w->CreateSlotHere<ELFHeader>();
647 : #if (V8_TARGET_ARCH_IA32 || V8_TARGET_ARCH_ARM || \
648 : (V8_TARGET_ARCH_X64 && V8_TARGET_ARCH_32_BIT))
649 : const uint8_t ident[16] = {0x7F, 'E', 'L', 'F', 1, 1, 1, 0,
650 : 0, 0, 0, 0, 0, 0, 0, 0};
651 : #elif(V8_TARGET_ARCH_X64 && V8_TARGET_ARCH_64_BIT) || \
652 : (V8_TARGET_ARCH_PPC64 && V8_TARGET_LITTLE_ENDIAN)
653 : const uint8_t ident[16] = {0x7F, 'E', 'L', 'F', 2, 1, 1, 0,
654 0 : 0, 0, 0, 0, 0, 0, 0, 0};
655 : #elif V8_TARGET_ARCH_PPC64 && V8_TARGET_BIG_ENDIAN && V8_OS_LINUX
656 : const uint8_t ident[16] = {0x7F, 'E', 'L', 'F', 2, 2, 1, 0,
657 : 0, 0, 0, 0, 0, 0, 0, 0};
658 : #elif V8_TARGET_ARCH_S390X
659 : const uint8_t ident[16] = {0x7F, 'E', 'L', 'F', 2, 2, 1, 3,
660 : 0, 0, 0, 0, 0, 0, 0, 0};
661 : #elif V8_TARGET_ARCH_S390
662 : const uint8_t ident[16] = {0x7F, 'E', 'L', 'F', 1, 2, 1, 3,
663 : 0, 0, 0, 0, 0, 0, 0, 0};
664 : #else
665 : #error Unsupported target architecture.
666 : #endif
667 0 : memcpy(header->ident, ident, 16);
668 0 : header->type = 1;
669 : #if V8_TARGET_ARCH_IA32
670 : header->machine = 3;
671 : #elif V8_TARGET_ARCH_X64
672 : // Processor identification value for x64 is 62 as defined in
673 : // System V ABI, AMD64 Supplement
674 : // http://www.x86-64.org/documentation/abi.pdf
675 0 : header->machine = 62;
676 : #elif V8_TARGET_ARCH_ARM
677 : // Set to EM_ARM, defined as 40, in "ARM ELF File Format" at
678 : // infocenter.arm.com/help/topic/com.arm.doc.dui0101a/DUI0101A_Elf.pdf
679 : header->machine = 40;
680 : #elif V8_TARGET_ARCH_PPC64 && V8_OS_LINUX
681 : // Set to EM_PPC64, defined as 21, in Power ABI,
682 : // Join the next 4 lines, omitting the spaces and double-slashes.
683 : // https://www-03.ibm.com/technologyconnect/tgcm/TGCMFileServlet.wss/
684 : // ABI64BitOpenPOWERv1.1_16July2015_pub.pdf?
685 : // id=B81AEC1A37F5DAF185257C3E004E8845&linkid=1n0000&c_t=
686 : // c9xw7v5dzsj7gt1ifgf4cjbcnskqptmr
687 : header->machine = 21;
688 : #elif V8_TARGET_ARCH_S390
689 : // Processor identification value is 22 (EM_S390) as defined in the ABI:
690 : // http://refspecs.linuxbase.org/ELF/zSeries/lzsabi0_s390.html#AEN1691
691 : // http://refspecs.linuxbase.org/ELF/zSeries/lzsabi0_zSeries.html#AEN1599
692 : header->machine = 22;
693 : #else
694 : #error Unsupported target architecture.
695 : #endif
696 0 : header->version = 1;
697 0 : header->entry = 0;
698 0 : header->pht_offset = 0;
699 0 : header->sht_offset = sizeof(ELFHeader); // Section table follows header.
700 0 : header->flags = 0;
701 0 : header->header_size = sizeof(ELFHeader);
702 0 : header->pht_entry_size = 0;
703 0 : header->pht_entry_num = 0;
704 0 : header->sht_entry_size = sizeof(ELFSection::Header);
705 0 : header->sht_entry_num = sections_.size();
706 0 : header->sht_strtab_index = 1;
707 0 : }
708 :
709 0 : void WriteSectionTable(Writer* w) {
710 : // Section headers table immediately follows file header.
711 : DCHECK(w->position() == sizeof(ELFHeader));
712 :
713 : Writer::Slot<ELFSection::Header> headers =
714 : w->CreateSlotsHere<ELFSection::Header>(
715 0 : static_cast<uint32_t>(sections_.size()));
716 :
717 : // String table for section table is the first section.
718 : ELFStringTable* strtab = static_cast<ELFStringTable*>(SectionAt(1));
719 : strtab->AttachWriter(w);
720 : uint32_t index = 0;
721 0 : for (ELFSection* section : sections_) {
722 0 : section->PopulateHeader(headers.at(index), strtab);
723 0 : index++;
724 : }
725 : strtab->DetachWriter();
726 0 : }
727 :
728 : int SectionHeaderPosition(uint32_t section_index) {
729 : return sizeof(ELFHeader) + sizeof(ELFSection::Header) * section_index;
730 : }
731 :
732 0 : void WriteSections(Writer* w) {
733 : Writer::Slot<ELFSection::Header> headers =
734 : w->SlotAt<ELFSection::Header>(sizeof(ELFHeader));
735 :
736 : uint32_t index = 0;
737 0 : for (ELFSection* section : sections_) {
738 0 : section->WriteBody(headers.at(index), w);
739 0 : index++;
740 : }
741 0 : }
742 :
743 : ZoneChunkList<ELFSection*> sections_;
744 : };
745 :
746 : class ELFSymbol {
747 : public:
748 : enum Type {
749 : TYPE_NOTYPE = 0,
750 : TYPE_OBJECT = 1,
751 : TYPE_FUNC = 2,
752 : TYPE_SECTION = 3,
753 : TYPE_FILE = 4,
754 : TYPE_LOPROC = 13,
755 : TYPE_HIPROC = 15
756 : };
757 :
758 : enum Binding {
759 : BIND_LOCAL = 0,
760 : BIND_GLOBAL = 1,
761 : BIND_WEAK = 2,
762 : BIND_LOPROC = 13,
763 : BIND_HIPROC = 15
764 : };
765 :
766 : ELFSymbol(const char* name,
767 : uintptr_t value,
768 : uintptr_t size,
769 : Binding binding,
770 : Type type,
771 : uint16_t section)
772 : : name(name),
773 : value(value),
774 : size(size),
775 : info((binding << 4) | type),
776 : other(0),
777 0 : section(section) {
778 : }
779 :
780 : Binding binding() const {
781 0 : return static_cast<Binding>(info >> 4);
782 : }
783 : #if (V8_TARGET_ARCH_IA32 || V8_TARGET_ARCH_ARM || \
784 : (V8_TARGET_ARCH_X64 && V8_TARGET_ARCH_32_BIT) || \
785 : (V8_TARGET_ARCH_S390 && V8_TARGET_ARCH_32_BIT))
786 : struct SerializedLayout {
787 : SerializedLayout(uint32_t name,
788 : uintptr_t value,
789 : uintptr_t size,
790 : Binding binding,
791 : Type type,
792 : uint16_t section)
793 : : name(name),
794 : value(value),
795 : size(size),
796 : info((binding << 4) | type),
797 : other(0),
798 : section(section) {
799 : }
800 :
801 : uint32_t name;
802 : uintptr_t value;
803 : uintptr_t size;
804 : uint8_t info;
805 : uint8_t other;
806 : uint16_t section;
807 : };
808 : #elif(V8_TARGET_ARCH_X64 && V8_TARGET_ARCH_64_BIT) || \
809 : (V8_TARGET_ARCH_PPC64 && V8_OS_LINUX) || V8_TARGET_ARCH_S390X
810 : struct SerializedLayout {
811 : SerializedLayout(uint32_t name,
812 : uintptr_t value,
813 : uintptr_t size,
814 : Binding binding,
815 : Type type,
816 : uint16_t section)
817 : : name(name),
818 : info((binding << 4) | type),
819 : other(0),
820 : section(section),
821 : value(value),
822 : size(size) {
823 : }
824 :
825 : uint32_t name;
826 : uint8_t info;
827 : uint8_t other;
828 : uint16_t section;
829 : uintptr_t value;
830 : uintptr_t size;
831 : };
832 : #endif
833 :
834 0 : void Write(Writer::Slot<SerializedLayout> s, ELFStringTable* t) const {
835 : // Convert symbol names from strings to indexes in the string table.
836 0 : s->name = static_cast<uint32_t>(t->Add(name));
837 0 : s->value = value;
838 0 : s->size = size;
839 0 : s->info = info;
840 0 : s->other = other;
841 0 : s->section = section;
842 0 : }
843 :
844 : private:
845 : const char* name;
846 : uintptr_t value;
847 : uintptr_t size;
848 : uint8_t info;
849 : uint8_t other;
850 : uint16_t section;
851 : };
852 :
853 :
854 0 : class ELFSymbolTable : public ELFSection {
855 : public:
856 : ELFSymbolTable(const char* name, Zone* zone)
857 : : ELFSection(name, TYPE_SYMTAB, sizeof(uintptr_t)),
858 : locals_(zone),
859 0 : globals_(zone) {}
860 :
861 0 : void WriteBody(Writer::Slot<Header> header, Writer* w) override {
862 0 : w->Align(header->alignment);
863 0 : size_t total_symbols = locals_.size() + globals_.size() + 1;
864 0 : header->offset = w->position();
865 :
866 : Writer::Slot<ELFSymbol::SerializedLayout> symbols =
867 : w->CreateSlotsHere<ELFSymbol::SerializedLayout>(
868 0 : static_cast<uint32_t>(total_symbols));
869 :
870 0 : header->size = w->position() - header->offset;
871 :
872 : // String table for this symbol table should follow it in the section table.
873 : ELFStringTable* strtab =
874 0 : static_cast<ELFStringTable*>(w->debug_object()->SectionAt(index() + 1));
875 : strtab->AttachWriter(w);
876 : symbols.at(0).set(ELFSymbol::SerializedLayout(0,
877 : 0,
878 : 0,
879 : ELFSymbol::BIND_LOCAL,
880 : ELFSymbol::TYPE_NOTYPE,
881 : 0));
882 0 : WriteSymbolsList(&locals_, symbols.at(1), strtab);
883 : WriteSymbolsList(&globals_,
884 : symbols.at(static_cast<uint32_t>(locals_.size() + 1)),
885 0 : strtab);
886 : strtab->DetachWriter();
887 0 : }
888 :
889 0 : void Add(const ELFSymbol& symbol) {
890 0 : if (symbol.binding() == ELFSymbol::BIND_LOCAL) {
891 0 : locals_.push_back(symbol);
892 : } else {
893 0 : globals_.push_back(symbol);
894 : }
895 0 : }
896 :
897 : protected:
898 0 : void PopulateHeader(Writer::Slot<Header> header) override {
899 0 : ELFSection::PopulateHeader(header);
900 : // We are assuming that string table will follow symbol table.
901 0 : header->link = index() + 1;
902 0 : header->info = static_cast<uint32_t>(locals_.size() + 1);
903 0 : header->entry_size = sizeof(ELFSymbol::SerializedLayout);
904 0 : }
905 :
906 : private:
907 0 : void WriteSymbolsList(const ZoneChunkList<ELFSymbol>* src,
908 : Writer::Slot<ELFSymbol::SerializedLayout> dst,
909 : ELFStringTable* strtab) {
910 : int i = 0;
911 0 : for (const ELFSymbol& symbol : *src) {
912 0 : symbol.Write(dst.at(i++), strtab);
913 : }
914 0 : }
915 :
916 : ZoneChunkList<ELFSymbol> locals_;
917 : ZoneChunkList<ELFSymbol> globals_;
918 : };
919 : #endif // defined(__ELF)
920 :
921 :
922 : class LineInfo : public Malloced {
923 : public:
924 : void SetPosition(intptr_t pc, int pos, bool is_statement) {
925 0 : AddPCInfo(PCInfo(pc, pos, is_statement));
926 : }
927 :
928 : struct PCInfo {
929 : PCInfo(intptr_t pc, int pos, bool is_statement)
930 0 : : pc_(pc), pos_(pos), is_statement_(is_statement) {}
931 :
932 : intptr_t pc_;
933 : int pos_;
934 : bool is_statement_;
935 : };
936 :
937 : std::vector<PCInfo>* pc_info() { return &pc_info_; }
938 :
939 : private:
940 0 : void AddPCInfo(const PCInfo& pc_info) { pc_info_.push_back(pc_info); }
941 :
942 : std::vector<PCInfo> pc_info_;
943 : };
944 :
945 : class CodeDescription {
946 : public:
947 : #if V8_TARGET_ARCH_X64
948 : enum StackState {
949 : POST_RBP_PUSH,
950 : POST_RBP_SET,
951 : POST_RBP_POP,
952 : STACK_STATE_MAX
953 : };
954 : #endif
955 :
956 : CodeDescription(const char* name, Code code, SharedFunctionInfo shared,
957 : LineInfo* lineinfo)
958 0 : : name_(name), code_(code), shared_info_(shared), lineinfo_(lineinfo) {}
959 :
960 : const char* name() const {
961 : return name_;
962 : }
963 :
964 : LineInfo* lineinfo() const { return lineinfo_; }
965 :
966 : bool is_function() const {
967 : Code::Kind kind = code_->kind();
968 : return kind == Code::OPTIMIZED_FUNCTION;
969 : }
970 :
971 0 : bool has_scope_info() const { return !shared_info_.is_null(); }
972 :
973 : ScopeInfo scope_info() const {
974 : DCHECK(has_scope_info());
975 0 : return shared_info_->scope_info();
976 : }
977 :
978 : uintptr_t CodeStart() const {
979 0 : return static_cast<uintptr_t>(code_->InstructionStart());
980 : }
981 :
982 : uintptr_t CodeEnd() const {
983 0 : return static_cast<uintptr_t>(code_->InstructionEnd());
984 : }
985 :
986 0 : uintptr_t CodeSize() const {
987 0 : return CodeEnd() - CodeStart();
988 : }
989 :
990 : bool has_script() {
991 : return !shared_info_.is_null() && shared_info_->script()->IsScript();
992 : }
993 :
994 0 : Script script() { return Script::cast(shared_info_->script()); }
995 :
996 : bool IsLineInfoAvailable() { return lineinfo_ != nullptr; }
997 :
998 : #if V8_TARGET_ARCH_X64
999 : uintptr_t GetStackStateStartAddress(StackState state) const {
1000 : DCHECK(state < STACK_STATE_MAX);
1001 0 : return stack_state_start_addresses_[state];
1002 : }
1003 :
1004 : void SetStackStateStartAddress(StackState state, uintptr_t addr) {
1005 : DCHECK(state < STACK_STATE_MAX);
1006 0 : stack_state_start_addresses_[state] = addr;
1007 : }
1008 : #endif
1009 :
1010 0 : std::unique_ptr<char[]> GetFilename() {
1011 0 : if (!shared_info_.is_null()) {
1012 0 : return String::cast(script()->name())->ToCString();
1013 : } else {
1014 0 : std::unique_ptr<char[]> result(new char[1]);
1015 0 : result[0] = 0;
1016 : return result;
1017 : }
1018 : }
1019 :
1020 0 : int GetScriptLineNumber(int pos) {
1021 0 : if (!shared_info_.is_null()) {
1022 0 : return script()->GetLineNumber(pos) + 1;
1023 : } else {
1024 : return 0;
1025 : }
1026 : }
1027 :
1028 : private:
1029 : const char* name_;
1030 : Code code_;
1031 : SharedFunctionInfo shared_info_;
1032 : LineInfo* lineinfo_;
1033 : #if V8_TARGET_ARCH_X64
1034 : uintptr_t stack_state_start_addresses_[STACK_STATE_MAX];
1035 : #endif
1036 : };
1037 :
1038 : #if defined(__ELF)
1039 0 : static void CreateSymbolsTable(CodeDescription* desc, Zone* zone, ELF* elf,
1040 : size_t text_section_index) {
1041 : 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 : elf->AddSection(symtab);
1046 : elf->AddSection(strtab);
1047 :
1048 : symtab->Add(ELFSymbol("V8 Code", 0, 0, ELFSymbol::BIND_LOCAL,
1049 0 : ELFSymbol::TYPE_FILE, ELFSection::INDEX_ABSOLUTE));
1050 :
1051 : symtab->Add(ELFSymbol(desc->name(), 0, desc->CodeSize(),
1052 : ELFSymbol::BIND_GLOBAL, ELFSymbol::TYPE_FUNC,
1053 0 : text_section_index));
1054 0 : }
1055 : #endif // defined(__ELF)
1056 :
1057 :
1058 0 : class DebugInfoSection : public DebugSection {
1059 : public:
1060 : explicit DebugInfoSection(CodeDescription* desc)
1061 : #if defined(__ELF)
1062 : : ELFSection(".debug_info", TYPE_PROGBITS, 1),
1063 : #else
1064 : : MachOSection("__debug_info",
1065 : "__DWARF",
1066 : 1,
1067 : MachOSection::S_REGULAR | MachOSection::S_ATTR_DEBUG),
1068 : #endif
1069 0 : desc_(desc) { }
1070 :
1071 : // DWARF2 standard
1072 : enum DWARF2LocationOp {
1073 : DW_OP_reg0 = 0x50,
1074 : DW_OP_reg1 = 0x51,
1075 : DW_OP_reg2 = 0x52,
1076 : DW_OP_reg3 = 0x53,
1077 : DW_OP_reg4 = 0x54,
1078 : DW_OP_reg5 = 0x55,
1079 : DW_OP_reg6 = 0x56,
1080 : DW_OP_reg7 = 0x57,
1081 : DW_OP_reg8 = 0x58,
1082 : DW_OP_reg9 = 0x59,
1083 : DW_OP_reg10 = 0x5A,
1084 : DW_OP_reg11 = 0x5B,
1085 : DW_OP_reg12 = 0x5C,
1086 : DW_OP_reg13 = 0x5D,
1087 : DW_OP_reg14 = 0x5E,
1088 : DW_OP_reg15 = 0x5F,
1089 : DW_OP_reg16 = 0x60,
1090 : DW_OP_reg17 = 0x61,
1091 : DW_OP_reg18 = 0x62,
1092 : DW_OP_reg19 = 0x63,
1093 : DW_OP_reg20 = 0x64,
1094 : DW_OP_reg21 = 0x65,
1095 : DW_OP_reg22 = 0x66,
1096 : DW_OP_reg23 = 0x67,
1097 : DW_OP_reg24 = 0x68,
1098 : DW_OP_reg25 = 0x69,
1099 : DW_OP_reg26 = 0x6A,
1100 : DW_OP_reg27 = 0x6B,
1101 : DW_OP_reg28 = 0x6C,
1102 : DW_OP_reg29 = 0x6D,
1103 : DW_OP_reg30 = 0x6E,
1104 : DW_OP_reg31 = 0x6F,
1105 : DW_OP_fbreg = 0x91 // 1 param: SLEB128 offset
1106 : };
1107 :
1108 : enum DWARF2Encoding {
1109 : DW_ATE_ADDRESS = 0x1,
1110 : DW_ATE_SIGNED = 0x5
1111 : };
1112 :
1113 0 : bool WriteBodyInternal(Writer* w) override {
1114 : uintptr_t cu_start = w->position();
1115 : Writer::Slot<uint32_t> size = w->CreateSlotHere<uint32_t>();
1116 : uintptr_t start = w->position();
1117 0 : w->Write<uint16_t>(2); // DWARF version.
1118 0 : w->Write<uint32_t>(0); // Abbreviation table offset.
1119 0 : w->Write<uint8_t>(sizeof(intptr_t));
1120 :
1121 0 : w->WriteULEB128(1); // Abbreviation code.
1122 0 : w->WriteString(desc_->GetFilename().get());
1123 0 : w->Write<intptr_t>(desc_->CodeStart());
1124 0 : w->Write<intptr_t>(desc_->CodeStart() + desc_->CodeSize());
1125 0 : w->Write<uint32_t>(0);
1126 :
1127 0 : uint32_t ty_offset = static_cast<uint32_t>(w->position() - cu_start);
1128 0 : w->WriteULEB128(3);
1129 0 : w->Write<uint8_t>(kPointerSize);
1130 : w->WriteString("v8value");
1131 :
1132 0 : if (desc_->has_scope_info()) {
1133 0 : ScopeInfo scope = desc_->scope_info();
1134 0 : w->WriteULEB128(2);
1135 0 : w->WriteString(desc_->name());
1136 0 : w->Write<intptr_t>(desc_->CodeStart());
1137 0 : w->Write<intptr_t>(desc_->CodeStart() + desc_->CodeSize());
1138 : Writer::Slot<uint32_t> fb_block_size = w->CreateSlotHere<uint32_t>();
1139 : uintptr_t fb_block_start = w->position();
1140 : #if V8_TARGET_ARCH_IA32
1141 : w->Write<uint8_t>(DW_OP_reg5); // The frame pointer's here on ia32
1142 : #elif V8_TARGET_ARCH_X64
1143 0 : w->Write<uint8_t>(DW_OP_reg6); // and here on x64.
1144 : #elif V8_TARGET_ARCH_ARM
1145 : UNIMPLEMENTED();
1146 : #elif V8_TARGET_ARCH_MIPS
1147 : UNIMPLEMENTED();
1148 : #elif V8_TARGET_ARCH_MIPS64
1149 : UNIMPLEMENTED();
1150 : #elif V8_TARGET_ARCH_PPC64 && V8_OS_LINUX
1151 : w->Write<uint8_t>(DW_OP_reg31); // The frame pointer is here on PPC64.
1152 : #elif V8_TARGET_ARCH_S390
1153 : w->Write<uint8_t>(DW_OP_reg11); // The frame pointer's here on S390.
1154 : #else
1155 : #error Unsupported target architecture.
1156 : #endif
1157 0 : fb_block_size.set(static_cast<uint32_t>(w->position() - fb_block_start));
1158 :
1159 0 : int params = scope->ParameterCount();
1160 0 : int context_slots = scope->ContextLocalCount();
1161 : // The real slot ID is internal_slots + context_slot_id.
1162 : int internal_slots = Context::MIN_CONTEXT_SLOTS;
1163 : int current_abbreviation = 4;
1164 :
1165 : EmbeddedVector<char, 256> buffer;
1166 : StringBuilder builder(buffer.start(), buffer.length());
1167 :
1168 0 : for (int param = 0; param < params; ++param) {
1169 0 : w->WriteULEB128(current_abbreviation++);
1170 : builder.Reset();
1171 0 : builder.AddFormatted("param%d", param);
1172 0 : w->WriteString(builder.Finalize());
1173 0 : w->Write<uint32_t>(ty_offset);
1174 : Writer::Slot<uint32_t> block_size = w->CreateSlotHere<uint32_t>();
1175 : uintptr_t block_start = w->position();
1176 0 : w->Write<uint8_t>(DW_OP_fbreg);
1177 : w->WriteSLEB128(
1178 0 : JavaScriptFrameConstants::kLastParameterOffset +
1179 0 : kPointerSize * (params - param - 1));
1180 0 : block_size.set(static_cast<uint32_t>(w->position() - block_start));
1181 : }
1182 :
1183 : // See contexts.h for more information.
1184 : DCHECK_EQ(Context::MIN_CONTEXT_SLOTS, 4);
1185 : DCHECK_EQ(Context::SCOPE_INFO_INDEX, 0);
1186 : DCHECK_EQ(Context::PREVIOUS_INDEX, 1);
1187 : DCHECK_EQ(Context::EXTENSION_INDEX, 2);
1188 : DCHECK_EQ(Context::NATIVE_CONTEXT_INDEX, 3);
1189 0 : w->WriteULEB128(current_abbreviation++);
1190 : w->WriteString(".scope_info");
1191 0 : w->WriteULEB128(current_abbreviation++);
1192 : w->WriteString(".previous");
1193 0 : w->WriteULEB128(current_abbreviation++);
1194 : w->WriteString(".extension");
1195 0 : w->WriteULEB128(current_abbreviation++);
1196 : w->WriteString(".native_context");
1197 :
1198 0 : for (int context_slot = 0;
1199 : context_slot < context_slots;
1200 : ++context_slot) {
1201 0 : w->WriteULEB128(current_abbreviation++);
1202 : builder.Reset();
1203 0 : builder.AddFormatted("context_slot%d", context_slot + internal_slots);
1204 0 : w->WriteString(builder.Finalize());
1205 : }
1206 :
1207 : {
1208 0 : w->WriteULEB128(current_abbreviation++);
1209 : w->WriteString("__function");
1210 0 : w->Write<uint32_t>(ty_offset);
1211 : Writer::Slot<uint32_t> block_size = w->CreateSlotHere<uint32_t>();
1212 : uintptr_t block_start = w->position();
1213 0 : w->Write<uint8_t>(DW_OP_fbreg);
1214 0 : w->WriteSLEB128(JavaScriptFrameConstants::kFunctionOffset);
1215 0 : block_size.set(static_cast<uint32_t>(w->position() - block_start));
1216 : }
1217 :
1218 : {
1219 0 : w->WriteULEB128(current_abbreviation++);
1220 : w->WriteString("__context");
1221 0 : w->Write<uint32_t>(ty_offset);
1222 : Writer::Slot<uint32_t> block_size = w->CreateSlotHere<uint32_t>();
1223 : uintptr_t block_start = w->position();
1224 0 : w->Write<uint8_t>(DW_OP_fbreg);
1225 0 : w->WriteSLEB128(StandardFrameConstants::kContextOffset);
1226 0 : block_size.set(static_cast<uint32_t>(w->position() - block_start));
1227 : }
1228 :
1229 0 : w->WriteULEB128(0); // Terminate the sub program.
1230 : }
1231 :
1232 0 : w->WriteULEB128(0); // Terminate the compile unit.
1233 0 : size.set(static_cast<uint32_t>(w->position() - start));
1234 0 : return true;
1235 : }
1236 :
1237 : private:
1238 : CodeDescription* desc_;
1239 : };
1240 :
1241 :
1242 0 : class DebugAbbrevSection : public DebugSection {
1243 : public:
1244 : explicit DebugAbbrevSection(CodeDescription* desc)
1245 : #ifdef __ELF
1246 : : ELFSection(".debug_abbrev", TYPE_PROGBITS, 1),
1247 : #else
1248 : : MachOSection("__debug_abbrev",
1249 : "__DWARF",
1250 : 1,
1251 : MachOSection::S_REGULAR | MachOSection::S_ATTR_DEBUG),
1252 : #endif
1253 0 : desc_(desc) { }
1254 :
1255 : // DWARF2 standard, figure 14.
1256 : enum DWARF2Tags {
1257 : DW_TAG_FORMAL_PARAMETER = 0x05,
1258 : DW_TAG_POINTER_TYPE = 0xF,
1259 : DW_TAG_COMPILE_UNIT = 0x11,
1260 : DW_TAG_STRUCTURE_TYPE = 0x13,
1261 : DW_TAG_BASE_TYPE = 0x24,
1262 : DW_TAG_SUBPROGRAM = 0x2E,
1263 : DW_TAG_VARIABLE = 0x34
1264 : };
1265 :
1266 : // DWARF2 standard, figure 16.
1267 : enum DWARF2ChildrenDetermination {
1268 : DW_CHILDREN_NO = 0,
1269 : DW_CHILDREN_YES = 1
1270 : };
1271 :
1272 : // DWARF standard, figure 17.
1273 : enum DWARF2Attribute {
1274 : DW_AT_LOCATION = 0x2,
1275 : DW_AT_NAME = 0x3,
1276 : DW_AT_BYTE_SIZE = 0xB,
1277 : DW_AT_STMT_LIST = 0x10,
1278 : DW_AT_LOW_PC = 0x11,
1279 : DW_AT_HIGH_PC = 0x12,
1280 : DW_AT_ENCODING = 0x3E,
1281 : DW_AT_FRAME_BASE = 0x40,
1282 : DW_AT_TYPE = 0x49
1283 : };
1284 :
1285 : // DWARF2 standard, figure 19.
1286 : enum DWARF2AttributeForm {
1287 : DW_FORM_ADDR = 0x1,
1288 : DW_FORM_BLOCK4 = 0x4,
1289 : DW_FORM_STRING = 0x8,
1290 : DW_FORM_DATA4 = 0x6,
1291 : DW_FORM_BLOCK = 0x9,
1292 : DW_FORM_DATA1 = 0xB,
1293 : DW_FORM_FLAG = 0xC,
1294 : DW_FORM_REF4 = 0x13
1295 : };
1296 :
1297 0 : void WriteVariableAbbreviation(Writer* w,
1298 : int abbreviation_code,
1299 : bool has_value,
1300 : bool is_parameter) {
1301 0 : w->WriteULEB128(abbreviation_code);
1302 0 : w->WriteULEB128(is_parameter ? DW_TAG_FORMAL_PARAMETER : DW_TAG_VARIABLE);
1303 0 : w->Write<uint8_t>(DW_CHILDREN_NO);
1304 0 : w->WriteULEB128(DW_AT_NAME);
1305 0 : w->WriteULEB128(DW_FORM_STRING);
1306 0 : if (has_value) {
1307 0 : w->WriteULEB128(DW_AT_TYPE);
1308 0 : w->WriteULEB128(DW_FORM_REF4);
1309 0 : w->WriteULEB128(DW_AT_LOCATION);
1310 0 : w->WriteULEB128(DW_FORM_BLOCK4);
1311 : }
1312 0 : w->WriteULEB128(0);
1313 0 : w->WriteULEB128(0);
1314 0 : }
1315 :
1316 0 : bool WriteBodyInternal(Writer* w) override {
1317 : int current_abbreviation = 1;
1318 0 : bool extra_info = desc_->has_scope_info();
1319 : DCHECK(desc_->IsLineInfoAvailable());
1320 0 : w->WriteULEB128(current_abbreviation++);
1321 0 : w->WriteULEB128(DW_TAG_COMPILE_UNIT);
1322 0 : w->Write<uint8_t>(extra_info ? DW_CHILDREN_YES : DW_CHILDREN_NO);
1323 0 : w->WriteULEB128(DW_AT_NAME);
1324 0 : w->WriteULEB128(DW_FORM_STRING);
1325 0 : w->WriteULEB128(DW_AT_LOW_PC);
1326 0 : w->WriteULEB128(DW_FORM_ADDR);
1327 0 : w->WriteULEB128(DW_AT_HIGH_PC);
1328 0 : w->WriteULEB128(DW_FORM_ADDR);
1329 0 : w->WriteULEB128(DW_AT_STMT_LIST);
1330 0 : w->WriteULEB128(DW_FORM_DATA4);
1331 0 : w->WriteULEB128(0);
1332 0 : w->WriteULEB128(0);
1333 :
1334 0 : if (extra_info) {
1335 0 : ScopeInfo scope = desc_->scope_info();
1336 0 : int params = scope->ParameterCount();
1337 0 : int context_slots = scope->ContextLocalCount();
1338 : // The real slot ID is internal_slots + context_slot_id.
1339 : int internal_slots = Context::MIN_CONTEXT_SLOTS;
1340 : // Total children is params + context_slots + internal_slots + 2
1341 : // (__function and __context).
1342 :
1343 : // The extra duplication below seems to be necessary to keep
1344 : // gdb from getting upset on OSX.
1345 0 : w->WriteULEB128(current_abbreviation++); // Abbreviation code.
1346 0 : w->WriteULEB128(DW_TAG_SUBPROGRAM);
1347 0 : w->Write<uint8_t>(DW_CHILDREN_YES);
1348 0 : w->WriteULEB128(DW_AT_NAME);
1349 0 : w->WriteULEB128(DW_FORM_STRING);
1350 0 : w->WriteULEB128(DW_AT_LOW_PC);
1351 0 : w->WriteULEB128(DW_FORM_ADDR);
1352 0 : w->WriteULEB128(DW_AT_HIGH_PC);
1353 0 : w->WriteULEB128(DW_FORM_ADDR);
1354 0 : w->WriteULEB128(DW_AT_FRAME_BASE);
1355 0 : w->WriteULEB128(DW_FORM_BLOCK4);
1356 0 : w->WriteULEB128(0);
1357 0 : w->WriteULEB128(0);
1358 :
1359 0 : w->WriteULEB128(current_abbreviation++);
1360 0 : w->WriteULEB128(DW_TAG_STRUCTURE_TYPE);
1361 0 : w->Write<uint8_t>(DW_CHILDREN_NO);
1362 0 : w->WriteULEB128(DW_AT_BYTE_SIZE);
1363 0 : w->WriteULEB128(DW_FORM_DATA1);
1364 0 : w->WriteULEB128(DW_AT_NAME);
1365 0 : w->WriteULEB128(DW_FORM_STRING);
1366 0 : w->WriteULEB128(0);
1367 0 : w->WriteULEB128(0);
1368 :
1369 0 : for (int param = 0; param < params; ++param) {
1370 0 : WriteVariableAbbreviation(w, current_abbreviation++, true, true);
1371 : }
1372 :
1373 0 : for (int internal_slot = 0;
1374 : internal_slot < internal_slots;
1375 : ++internal_slot) {
1376 0 : WriteVariableAbbreviation(w, current_abbreviation++, false, false);
1377 : }
1378 :
1379 0 : for (int context_slot = 0;
1380 : context_slot < context_slots;
1381 : ++context_slot) {
1382 0 : WriteVariableAbbreviation(w, current_abbreviation++, false, false);
1383 : }
1384 :
1385 : // The function.
1386 0 : WriteVariableAbbreviation(w, current_abbreviation++, true, false);
1387 :
1388 : // The context.
1389 0 : WriteVariableAbbreviation(w, current_abbreviation++, true, false);
1390 :
1391 0 : w->WriteULEB128(0); // Terminate the sibling list.
1392 : }
1393 :
1394 0 : w->WriteULEB128(0); // Terminate the table.
1395 0 : return true;
1396 : }
1397 :
1398 : private:
1399 : CodeDescription* desc_;
1400 : };
1401 :
1402 :
1403 0 : class DebugLineSection : public DebugSection {
1404 : public:
1405 : explicit DebugLineSection(CodeDescription* desc)
1406 : #ifdef __ELF
1407 : : ELFSection(".debug_line", TYPE_PROGBITS, 1),
1408 : #else
1409 : : MachOSection("__debug_line",
1410 : "__DWARF",
1411 : 1,
1412 : MachOSection::S_REGULAR | MachOSection::S_ATTR_DEBUG),
1413 : #endif
1414 0 : desc_(desc) { }
1415 :
1416 : // DWARF2 standard, figure 34.
1417 : enum DWARF2Opcodes {
1418 : DW_LNS_COPY = 1,
1419 : DW_LNS_ADVANCE_PC = 2,
1420 : DW_LNS_ADVANCE_LINE = 3,
1421 : DW_LNS_SET_FILE = 4,
1422 : DW_LNS_SET_COLUMN = 5,
1423 : DW_LNS_NEGATE_STMT = 6
1424 : };
1425 :
1426 : // DWARF2 standard, figure 35.
1427 : enum DWARF2ExtendedOpcode {
1428 : DW_LNE_END_SEQUENCE = 1,
1429 : DW_LNE_SET_ADDRESS = 2,
1430 : DW_LNE_DEFINE_FILE = 3
1431 : };
1432 :
1433 0 : bool WriteBodyInternal(Writer* w) override {
1434 : // Write prologue.
1435 : Writer::Slot<uint32_t> total_length = w->CreateSlotHere<uint32_t>();
1436 : uintptr_t start = w->position();
1437 :
1438 : // Used for special opcodes
1439 0 : const int8_t line_base = 1;
1440 0 : const uint8_t line_range = 7;
1441 : const int8_t max_line_incr = (line_base + line_range - 1);
1442 0 : const uint8_t opcode_base = DW_LNS_NEGATE_STMT + 1;
1443 :
1444 0 : w->Write<uint16_t>(2); // Field version.
1445 : Writer::Slot<uint32_t> prologue_length = w->CreateSlotHere<uint32_t>();
1446 : uintptr_t prologue_start = w->position();
1447 0 : w->Write<uint8_t>(1); // Field minimum_instruction_length.
1448 0 : w->Write<uint8_t>(1); // Field default_is_stmt.
1449 0 : w->Write<int8_t>(line_base); // Field line_base.
1450 0 : w->Write<uint8_t>(line_range); // Field line_range.
1451 0 : w->Write<uint8_t>(opcode_base); // Field opcode_base.
1452 0 : w->Write<uint8_t>(0); // DW_LNS_COPY operands count.
1453 0 : w->Write<uint8_t>(1); // DW_LNS_ADVANCE_PC operands count.
1454 0 : w->Write<uint8_t>(1); // DW_LNS_ADVANCE_LINE operands count.
1455 0 : w->Write<uint8_t>(1); // DW_LNS_SET_FILE operands count.
1456 0 : w->Write<uint8_t>(1); // DW_LNS_SET_COLUMN operands count.
1457 0 : w->Write<uint8_t>(0); // DW_LNS_NEGATE_STMT operands count.
1458 0 : w->Write<uint8_t>(0); // Empty include_directories sequence.
1459 0 : w->WriteString(desc_->GetFilename().get()); // File name.
1460 0 : w->WriteULEB128(0); // Current directory.
1461 0 : w->WriteULEB128(0); // Unknown modification time.
1462 0 : w->WriteULEB128(0); // Unknown file size.
1463 0 : w->Write<uint8_t>(0);
1464 0 : prologue_length.set(static_cast<uint32_t>(w->position() - prologue_start));
1465 :
1466 0 : WriteExtendedOpcode(w, DW_LNE_SET_ADDRESS, sizeof(intptr_t));
1467 0 : w->Write<intptr_t>(desc_->CodeStart());
1468 0 : w->Write<uint8_t>(DW_LNS_COPY);
1469 :
1470 : intptr_t pc = 0;
1471 : intptr_t line = 1;
1472 : bool is_statement = true;
1473 :
1474 0 : std::vector<LineInfo::PCInfo>* pc_info = desc_->lineinfo()->pc_info();
1475 0 : std::sort(pc_info->begin(), pc_info->end(), &ComparePCInfo);
1476 :
1477 0 : for (size_t i = 0; i < pc_info->size(); i++) {
1478 : LineInfo::PCInfo* info = &pc_info->at(i);
1479 : DCHECK(info->pc_ >= pc);
1480 :
1481 : // Reduce bloating in the debug line table by removing duplicate line
1482 : // entries (per DWARF2 standard).
1483 0 : intptr_t new_line = desc_->GetScriptLineNumber(info->pos_);
1484 0 : if (new_line == line) {
1485 : continue;
1486 : }
1487 :
1488 : // Mark statement boundaries. For a better debugging experience, mark
1489 : // the last pc address in the function as a statement (e.g. "}"), so that
1490 : // a user can see the result of the last line executed in the function,
1491 : // should control reach the end.
1492 0 : if ((i + 1) == pc_info->size()) {
1493 0 : if (!is_statement) {
1494 0 : w->Write<uint8_t>(DW_LNS_NEGATE_STMT);
1495 : }
1496 0 : } else if (is_statement != info->is_statement_) {
1497 0 : w->Write<uint8_t>(DW_LNS_NEGATE_STMT);
1498 0 : is_statement = !is_statement;
1499 : }
1500 :
1501 : // Generate special opcodes, if possible. This results in more compact
1502 : // debug line tables. See the DWARF 2.0 standard to learn more about
1503 : // special opcodes.
1504 0 : uintptr_t pc_diff = info->pc_ - pc;
1505 0 : intptr_t line_diff = new_line - line;
1506 :
1507 : // Compute special opcode (see DWARF 2.0 standard)
1508 : intptr_t special_opcode = (line_diff - line_base) +
1509 0 : (line_range * pc_diff) + opcode_base;
1510 :
1511 : // If special_opcode is less than or equal to 255, it can be used as a
1512 : // special opcode. If line_diff is larger than the max line increment
1513 : // allowed for a special opcode, or if line_diff is less than the minimum
1514 : // line that can be added to the line register (i.e. line_base), then
1515 : // special_opcode can't be used.
1516 0 : if ((special_opcode >= opcode_base) && (special_opcode <= 255) &&
1517 0 : (line_diff <= max_line_incr) && (line_diff >= line_base)) {
1518 0 : w->Write<uint8_t>(special_opcode);
1519 : } else {
1520 0 : w->Write<uint8_t>(DW_LNS_ADVANCE_PC);
1521 0 : w->WriteSLEB128(pc_diff);
1522 0 : w->Write<uint8_t>(DW_LNS_ADVANCE_LINE);
1523 0 : w->WriteSLEB128(line_diff);
1524 0 : w->Write<uint8_t>(DW_LNS_COPY);
1525 : }
1526 :
1527 : // Increment the pc and line operands.
1528 0 : pc += pc_diff;
1529 : line += line_diff;
1530 : }
1531 : // Advance the pc to the end of the routine, since the end sequence opcode
1532 : // requires this.
1533 0 : w->Write<uint8_t>(DW_LNS_ADVANCE_PC);
1534 0 : w->WriteSLEB128(desc_->CodeSize() - pc);
1535 0 : WriteExtendedOpcode(w, DW_LNE_END_SEQUENCE, 0);
1536 0 : total_length.set(static_cast<uint32_t>(w->position() - start));
1537 0 : return true;
1538 : }
1539 :
1540 : private:
1541 0 : void WriteExtendedOpcode(Writer* w,
1542 : DWARF2ExtendedOpcode op,
1543 : size_t operands_size) {
1544 0 : w->Write<uint8_t>(0);
1545 0 : w->WriteULEB128(operands_size + 1);
1546 0 : w->Write<uint8_t>(op);
1547 0 : }
1548 :
1549 0 : static bool ComparePCInfo(const LineInfo::PCInfo& a,
1550 : const LineInfo::PCInfo& b) {
1551 0 : if (a.pc_ == b.pc_) {
1552 0 : if (a.is_statement_ != b.is_statement_) {
1553 0 : return !b.is_statement_;
1554 : }
1555 : return false;
1556 : }
1557 0 : return a.pc_ < b.pc_;
1558 : }
1559 :
1560 : CodeDescription* desc_;
1561 : };
1562 :
1563 :
1564 : #if V8_TARGET_ARCH_X64
1565 :
1566 0 : class UnwindInfoSection : public DebugSection {
1567 : public:
1568 : explicit UnwindInfoSection(CodeDescription* desc);
1569 : bool WriteBodyInternal(Writer* w) override;
1570 :
1571 : int WriteCIE(Writer* w);
1572 : void WriteFDE(Writer* w, int);
1573 :
1574 : void WriteFDEStateOnEntry(Writer* w);
1575 : void WriteFDEStateAfterRBPPush(Writer* w);
1576 : void WriteFDEStateAfterRBPSet(Writer* w);
1577 : void WriteFDEStateAfterRBPPop(Writer* w);
1578 :
1579 : void WriteLength(Writer* w,
1580 : Writer::Slot<uint32_t>* length_slot,
1581 : int initial_position);
1582 :
1583 : private:
1584 : CodeDescription* desc_;
1585 :
1586 : // DWARF3 Specification, Table 7.23
1587 : enum CFIInstructions {
1588 : DW_CFA_ADVANCE_LOC = 0x40,
1589 : DW_CFA_OFFSET = 0x80,
1590 : DW_CFA_RESTORE = 0xC0,
1591 : DW_CFA_NOP = 0x00,
1592 : DW_CFA_SET_LOC = 0x01,
1593 : DW_CFA_ADVANCE_LOC1 = 0x02,
1594 : DW_CFA_ADVANCE_LOC2 = 0x03,
1595 : DW_CFA_ADVANCE_LOC4 = 0x04,
1596 : DW_CFA_OFFSET_EXTENDED = 0x05,
1597 : DW_CFA_RESTORE_EXTENDED = 0x06,
1598 : DW_CFA_UNDEFINED = 0x07,
1599 : DW_CFA_SAME_VALUE = 0x08,
1600 : DW_CFA_REGISTER = 0x09,
1601 : DW_CFA_REMEMBER_STATE = 0x0A,
1602 : DW_CFA_RESTORE_STATE = 0x0B,
1603 : DW_CFA_DEF_CFA = 0x0C,
1604 : DW_CFA_DEF_CFA_REGISTER = 0x0D,
1605 : DW_CFA_DEF_CFA_OFFSET = 0x0E,
1606 :
1607 : DW_CFA_DEF_CFA_EXPRESSION = 0x0F,
1608 : DW_CFA_EXPRESSION = 0x10,
1609 : DW_CFA_OFFSET_EXTENDED_SF = 0x11,
1610 : DW_CFA_DEF_CFA_SF = 0x12,
1611 : DW_CFA_DEF_CFA_OFFSET_SF = 0x13,
1612 : DW_CFA_VAL_OFFSET = 0x14,
1613 : DW_CFA_VAL_OFFSET_SF = 0x15,
1614 : DW_CFA_VAL_EXPRESSION = 0x16
1615 : };
1616 :
1617 : // System V ABI, AMD64 Supplement, Version 0.99.5, Figure 3.36
1618 : enum RegisterMapping {
1619 : // Only the relevant ones have been added to reduce clutter.
1620 : AMD64_RBP = 6,
1621 : AMD64_RSP = 7,
1622 : AMD64_RA = 16
1623 : };
1624 :
1625 : enum CFIConstants {
1626 : CIE_ID = 0,
1627 : CIE_VERSION = 1,
1628 : CODE_ALIGN_FACTOR = 1,
1629 : DATA_ALIGN_FACTOR = 1,
1630 : RETURN_ADDRESS_REGISTER = AMD64_RA
1631 : };
1632 : };
1633 :
1634 :
1635 0 : void UnwindInfoSection::WriteLength(Writer* w,
1636 : Writer::Slot<uint32_t>* length_slot,
1637 : int initial_position) {
1638 0 : uint32_t align = (w->position() - initial_position) % kPointerSize;
1639 :
1640 0 : if (align != 0) {
1641 0 : for (uint32_t i = 0; i < (kPointerSize - align); i++) {
1642 0 : w->Write<uint8_t>(DW_CFA_NOP);
1643 : }
1644 : }
1645 :
1646 : DCHECK_EQ((w->position() - initial_position) % kPointerSize, 0);
1647 0 : length_slot->set(static_cast<uint32_t>(w->position() - initial_position));
1648 0 : }
1649 :
1650 :
1651 0 : UnwindInfoSection::UnwindInfoSection(CodeDescription* desc)
1652 : #ifdef __ELF
1653 : : ELFSection(".eh_frame", TYPE_X86_64_UNWIND, 1),
1654 : #else
1655 : : MachOSection("__eh_frame", "__TEXT", sizeof(uintptr_t),
1656 : MachOSection::S_REGULAR),
1657 : #endif
1658 0 : desc_(desc) { }
1659 :
1660 0 : int UnwindInfoSection::WriteCIE(Writer* w) {
1661 0 : Writer::Slot<uint32_t> cie_length_slot = w->CreateSlotHere<uint32_t>();
1662 : uint32_t cie_position = static_cast<uint32_t>(w->position());
1663 :
1664 : // Write out the CIE header. Currently no 'common instructions' are
1665 : // emitted onto the CIE; every FDE has its own set of instructions.
1666 :
1667 0 : w->Write<uint32_t>(CIE_ID);
1668 0 : w->Write<uint8_t>(CIE_VERSION);
1669 0 : w->Write<uint8_t>(0); // Null augmentation string.
1670 0 : w->WriteSLEB128(CODE_ALIGN_FACTOR);
1671 0 : w->WriteSLEB128(DATA_ALIGN_FACTOR);
1672 0 : w->Write<uint8_t>(RETURN_ADDRESS_REGISTER);
1673 :
1674 0 : WriteLength(w, &cie_length_slot, cie_position);
1675 :
1676 0 : return cie_position;
1677 : }
1678 :
1679 :
1680 0 : void UnwindInfoSection::WriteFDE(Writer* w, int cie_position) {
1681 : // The only FDE for this function. The CFA is the current RBP.
1682 0 : Writer::Slot<uint32_t> fde_length_slot = w->CreateSlotHere<uint32_t>();
1683 0 : int fde_position = static_cast<uint32_t>(w->position());
1684 0 : w->Write<int32_t>(fde_position - cie_position + 4);
1685 :
1686 0 : w->Write<uintptr_t>(desc_->CodeStart());
1687 0 : w->Write<uintptr_t>(desc_->CodeSize());
1688 :
1689 0 : WriteFDEStateOnEntry(w);
1690 0 : WriteFDEStateAfterRBPPush(w);
1691 0 : WriteFDEStateAfterRBPSet(w);
1692 0 : WriteFDEStateAfterRBPPop(w);
1693 :
1694 0 : WriteLength(w, &fde_length_slot, fde_position);
1695 0 : }
1696 :
1697 :
1698 0 : void UnwindInfoSection::WriteFDEStateOnEntry(Writer* w) {
1699 : // The first state, just after the control has been transferred to the the
1700 : // function.
1701 :
1702 : // RBP for this function will be the value of RSP after pushing the RBP
1703 : // for the previous function. The previous RBP has not been pushed yet.
1704 0 : w->Write<uint8_t>(DW_CFA_DEF_CFA_SF);
1705 0 : w->WriteULEB128(AMD64_RSP);
1706 0 : w->WriteSLEB128(-kPointerSize);
1707 :
1708 : // The RA is stored at location CFA + kCallerPCOffset. This is an invariant,
1709 : // and hence omitted from the next states.
1710 0 : w->Write<uint8_t>(DW_CFA_OFFSET_EXTENDED);
1711 0 : w->WriteULEB128(AMD64_RA);
1712 0 : w->WriteSLEB128(StandardFrameConstants::kCallerPCOffset);
1713 :
1714 : // The RBP of the previous function is still in RBP.
1715 0 : w->Write<uint8_t>(DW_CFA_SAME_VALUE);
1716 0 : w->WriteULEB128(AMD64_RBP);
1717 :
1718 : // Last location described by this entry.
1719 0 : w->Write<uint8_t>(DW_CFA_SET_LOC);
1720 : w->Write<uint64_t>(
1721 0 : desc_->GetStackStateStartAddress(CodeDescription::POST_RBP_PUSH));
1722 0 : }
1723 :
1724 :
1725 0 : void UnwindInfoSection::WriteFDEStateAfterRBPPush(Writer* w) {
1726 : // The second state, just after RBP has been pushed.
1727 :
1728 : // RBP / CFA for this function is now the current RSP, so just set the
1729 : // offset from the previous rule (from -8) to 0.
1730 0 : w->Write<uint8_t>(DW_CFA_DEF_CFA_OFFSET);
1731 0 : w->WriteULEB128(0);
1732 :
1733 : // The previous RBP is stored at CFA + kCallerFPOffset. This is an invariant
1734 : // in this and the next state, and hence omitted in the next state.
1735 0 : w->Write<uint8_t>(DW_CFA_OFFSET_EXTENDED);
1736 0 : w->WriteULEB128(AMD64_RBP);
1737 0 : w->WriteSLEB128(StandardFrameConstants::kCallerFPOffset);
1738 :
1739 : // Last location described by this entry.
1740 0 : w->Write<uint8_t>(DW_CFA_SET_LOC);
1741 : w->Write<uint64_t>(
1742 0 : desc_->GetStackStateStartAddress(CodeDescription::POST_RBP_SET));
1743 0 : }
1744 :
1745 :
1746 0 : void UnwindInfoSection::WriteFDEStateAfterRBPSet(Writer* w) {
1747 : // The third state, after the RBP has been set.
1748 :
1749 : // The CFA can now directly be set to RBP.
1750 0 : w->Write<uint8_t>(DW_CFA_DEF_CFA);
1751 0 : w->WriteULEB128(AMD64_RBP);
1752 0 : w->WriteULEB128(0);
1753 :
1754 : // Last location described by this entry.
1755 0 : w->Write<uint8_t>(DW_CFA_SET_LOC);
1756 : w->Write<uint64_t>(
1757 0 : desc_->GetStackStateStartAddress(CodeDescription::POST_RBP_POP));
1758 0 : }
1759 :
1760 :
1761 0 : void UnwindInfoSection::WriteFDEStateAfterRBPPop(Writer* w) {
1762 : // The fourth (final) state. The RBP has been popped (just before issuing a
1763 : // return).
1764 :
1765 : // The CFA can is now calculated in the same way as in the first state.
1766 0 : w->Write<uint8_t>(DW_CFA_DEF_CFA_SF);
1767 0 : w->WriteULEB128(AMD64_RSP);
1768 0 : w->WriteSLEB128(-kPointerSize);
1769 :
1770 : // The RBP
1771 0 : w->Write<uint8_t>(DW_CFA_OFFSET_EXTENDED);
1772 0 : w->WriteULEB128(AMD64_RBP);
1773 0 : w->WriteSLEB128(StandardFrameConstants::kCallerFPOffset);
1774 :
1775 : // Last location described by this entry.
1776 0 : w->Write<uint8_t>(DW_CFA_SET_LOC);
1777 0 : w->Write<uint64_t>(desc_->CodeEnd());
1778 0 : }
1779 :
1780 :
1781 0 : bool UnwindInfoSection::WriteBodyInternal(Writer* w) {
1782 0 : uint32_t cie_position = WriteCIE(w);
1783 0 : WriteFDE(w, cie_position);
1784 0 : return true;
1785 : }
1786 :
1787 :
1788 : #endif // V8_TARGET_ARCH_X64
1789 :
1790 0 : static void CreateDWARFSections(CodeDescription* desc,
1791 : Zone* zone,
1792 : DebugObject* obj) {
1793 0 : if (desc->IsLineInfoAvailable()) {
1794 : obj->AddSection(new(zone) DebugInfoSection(desc));
1795 : obj->AddSection(new(zone) DebugAbbrevSection(desc));
1796 : obj->AddSection(new(zone) DebugLineSection(desc));
1797 : }
1798 : #if V8_TARGET_ARCH_X64
1799 : obj->AddSection(new(zone) UnwindInfoSection(desc));
1800 : #endif
1801 0 : }
1802 :
1803 :
1804 : // -------------------------------------------------------------------
1805 : // Binary GDB JIT Interface as described in
1806 : // http://sourceware.org/gdb/onlinedocs/gdb/Declarations.html
1807 : extern "C" {
1808 : typedef enum {
1809 : JIT_NOACTION = 0,
1810 : JIT_REGISTER_FN,
1811 : JIT_UNREGISTER_FN
1812 : } JITAction;
1813 :
1814 : struct JITCodeEntry {
1815 : JITCodeEntry* next_;
1816 : JITCodeEntry* prev_;
1817 : Address symfile_addr_;
1818 : uint64_t symfile_size_;
1819 : };
1820 :
1821 : struct JITDescriptor {
1822 : uint32_t version_;
1823 : uint32_t action_flag_;
1824 : JITCodeEntry* relevant_entry_;
1825 : JITCodeEntry* first_entry_;
1826 : };
1827 :
1828 : // GDB will place breakpoint into this function.
1829 : // To prevent GCC from inlining or removing it we place noinline attribute
1830 : // and inline assembler statement inside.
1831 0 : void __attribute__((noinline)) __jit_debug_register_code() {
1832 0 : __asm__("");
1833 0 : }
1834 :
1835 : // GDB will inspect contents of this descriptor.
1836 : // Static initialization is necessary to prevent GDB from seeing
1837 : // uninitialized descriptor.
1838 : JITDescriptor __jit_debug_descriptor = {1, 0, nullptr, nullptr};
1839 :
1840 : #ifdef OBJECT_PRINT
1841 : void __gdb_print_v8_object(Object object) {
1842 : StdoutStream os;
1843 : object->Print(os);
1844 : os << std::flush;
1845 : }
1846 : #endif
1847 : }
1848 :
1849 :
1850 0 : static JITCodeEntry* CreateCodeEntry(Address symfile_addr,
1851 : uintptr_t symfile_size) {
1852 : JITCodeEntry* entry = static_cast<JITCodeEntry*>(
1853 0 : malloc(sizeof(JITCodeEntry) + symfile_size));
1854 :
1855 0 : entry->symfile_addr_ = reinterpret_cast<Address>(entry + 1);
1856 0 : entry->symfile_size_ = symfile_size;
1857 : MemCopy(reinterpret_cast<void*>(entry->symfile_addr_),
1858 0 : reinterpret_cast<void*>(symfile_addr), symfile_size);
1859 :
1860 0 : entry->prev_ = entry->next_ = nullptr;
1861 :
1862 0 : return entry;
1863 : }
1864 :
1865 :
1866 : static void DestroyCodeEntry(JITCodeEntry* entry) {
1867 0 : free(entry);
1868 : }
1869 :
1870 :
1871 0 : static void RegisterCodeEntry(JITCodeEntry* entry) {
1872 0 : entry->next_ = __jit_debug_descriptor.first_entry_;
1873 0 : if (entry->next_ != nullptr) entry->next_->prev_ = entry;
1874 : __jit_debug_descriptor.first_entry_ =
1875 0 : __jit_debug_descriptor.relevant_entry_ = entry;
1876 :
1877 0 : __jit_debug_descriptor.action_flag_ = JIT_REGISTER_FN;
1878 0 : __jit_debug_register_code();
1879 0 : }
1880 :
1881 :
1882 0 : static void UnregisterCodeEntry(JITCodeEntry* entry) {
1883 0 : if (entry->prev_ != nullptr) {
1884 0 : entry->prev_->next_ = entry->next_;
1885 : } else {
1886 0 : __jit_debug_descriptor.first_entry_ = entry->next_;
1887 : }
1888 :
1889 0 : if (entry->next_ != nullptr) {
1890 0 : entry->next_->prev_ = entry->prev_;
1891 : }
1892 :
1893 0 : __jit_debug_descriptor.relevant_entry_ = entry;
1894 0 : __jit_debug_descriptor.action_flag_ = JIT_UNREGISTER_FN;
1895 0 : __jit_debug_register_code();
1896 0 : }
1897 :
1898 :
1899 0 : static JITCodeEntry* CreateELFObject(CodeDescription* desc, Isolate* isolate) {
1900 : #ifdef __MACH_O
1901 : Zone zone(isolate->allocator(), ZONE_NAME);
1902 : MachO mach_o(&zone);
1903 : Writer w(&mach_o);
1904 :
1905 : mach_o.AddSection(new(&zone) MachOTextSection(kCodeAlignment,
1906 : desc->CodeStart(),
1907 : desc->CodeSize()));
1908 :
1909 : CreateDWARFSections(desc, &zone, &mach_o);
1910 :
1911 : mach_o.Write(&w, desc->CodeStart(), desc->CodeSize());
1912 : #else
1913 0 : Zone zone(isolate->allocator(), ZONE_NAME);
1914 0 : ELF elf(&zone);
1915 : Writer w(&elf);
1916 :
1917 : size_t text_section_index = elf.AddSection(new (&zone) FullHeaderELFSection(
1918 : ".text", ELFSection::TYPE_NOBITS, kCodeAlignment, desc->CodeStart(), 0,
1919 0 : desc->CodeSize(), ELFSection::FLAG_ALLOC | ELFSection::FLAG_EXEC));
1920 :
1921 0 : CreateSymbolsTable(desc, &zone, &elf, text_section_index);
1922 :
1923 0 : CreateDWARFSections(desc, &zone, &elf);
1924 :
1925 0 : elf.Write(&w);
1926 : #endif
1927 :
1928 0 : return CreateCodeEntry(reinterpret_cast<Address>(w.buffer()), w.position());
1929 : }
1930 :
1931 :
1932 : struct AddressRange {
1933 : Address start;
1934 : Address end;
1935 : };
1936 :
1937 : struct SplayTreeConfig {
1938 : typedef AddressRange Key;
1939 : typedef JITCodeEntry* Value;
1940 : static const AddressRange kNoKey;
1941 : static Value NoValue() { return nullptr; }
1942 : static int Compare(const AddressRange& a, const AddressRange& b) {
1943 : // ptrdiff_t probably doesn't fit in an int.
1944 0 : if (a.start < b.start) return -1;
1945 0 : if (a.start == b.start) return 0;
1946 : return 1;
1947 : }
1948 : };
1949 :
1950 : const AddressRange SplayTreeConfig::kNoKey = {0, 0};
1951 : typedef SplayTree<SplayTreeConfig> CodeMap;
1952 :
1953 0 : static CodeMap* GetCodeMap() {
1954 : static CodeMap* code_map = nullptr;
1955 0 : if (code_map == nullptr) code_map = new CodeMap();
1956 0 : return code_map;
1957 : }
1958 :
1959 :
1960 : static uint32_t HashCodeAddress(Address addr) {
1961 : static const uintptr_t kGoldenRatio = 2654435761u;
1962 0 : return static_cast<uint32_t>((addr >> kCodeAlignmentBits) * kGoldenRatio);
1963 : }
1964 :
1965 0 : static base::HashMap* GetLineMap() {
1966 : static base::HashMap* line_map = nullptr;
1967 0 : if (line_map == nullptr) {
1968 0 : line_map = new base::HashMap();
1969 : }
1970 0 : return line_map;
1971 : }
1972 :
1973 :
1974 0 : static void PutLineInfo(Address addr, LineInfo* info) {
1975 0 : base::HashMap* line_map = GetLineMap();
1976 : base::HashMap::Entry* e = line_map->LookupOrInsert(
1977 0 : reinterpret_cast<void*>(addr), HashCodeAddress(addr));
1978 0 : if (e->value != nullptr) delete static_cast<LineInfo*>(e->value);
1979 0 : e->value = info;
1980 0 : }
1981 :
1982 :
1983 0 : static LineInfo* GetLineInfo(Address addr) {
1984 0 : void* value = GetLineMap()->Remove(reinterpret_cast<void*>(addr),
1985 0 : HashCodeAddress(addr));
1986 0 : return static_cast<LineInfo*>(value);
1987 : }
1988 :
1989 :
1990 0 : static void AddUnwindInfo(CodeDescription* desc) {
1991 : #if V8_TARGET_ARCH_X64
1992 0 : if (desc->is_function()) {
1993 : // To avoid propagating unwinding information through
1994 : // compilation pipeline we use an approximation.
1995 : // For most use cases this should not affect usability.
1996 : static const int kFramePointerPushOffset = 1;
1997 : static const int kFramePointerSetOffset = 4;
1998 : static const int kFramePointerPopOffset = -3;
1999 :
2000 : uintptr_t frame_pointer_push_address =
2001 0 : desc->CodeStart() + kFramePointerPushOffset;
2002 :
2003 : uintptr_t frame_pointer_set_address =
2004 0 : desc->CodeStart() + kFramePointerSetOffset;
2005 :
2006 : uintptr_t frame_pointer_pop_address =
2007 0 : desc->CodeEnd() + kFramePointerPopOffset;
2008 :
2009 : desc->SetStackStateStartAddress(CodeDescription::POST_RBP_PUSH,
2010 : frame_pointer_push_address);
2011 : desc->SetStackStateStartAddress(CodeDescription::POST_RBP_SET,
2012 : frame_pointer_set_address);
2013 : desc->SetStackStateStartAddress(CodeDescription::POST_RBP_POP,
2014 : frame_pointer_pop_address);
2015 : } else {
2016 : desc->SetStackStateStartAddress(CodeDescription::POST_RBP_PUSH,
2017 : desc->CodeStart());
2018 : desc->SetStackStateStartAddress(CodeDescription::POST_RBP_SET,
2019 : desc->CodeStart());
2020 : desc->SetStackStateStartAddress(CodeDescription::POST_RBP_POP,
2021 : desc->CodeEnd());
2022 : }
2023 : #endif // V8_TARGET_ARCH_X64
2024 0 : }
2025 :
2026 :
2027 : static base::LazyMutex mutex = LAZY_MUTEX_INITIALIZER;
2028 :
2029 :
2030 : // Remove entries from the splay tree that intersect the given address range,
2031 : // and deregister them from GDB.
2032 0 : static void RemoveJITCodeEntries(CodeMap* map, const AddressRange& range) {
2033 : DCHECK(range.start < range.end);
2034 : CodeMap::Locator cur;
2035 0 : if (map->FindGreatestLessThan(range, &cur) || map->FindLeast(&cur)) {
2036 : // Skip entries that are entirely less than the range of interest.
2037 0 : while (cur.key().end <= range.start) {
2038 : // CodeMap::FindLeastGreaterThan succeeds for entries whose key is greater
2039 : // than _or equal to_ the given key, so we have to advance our key to get
2040 : // the next one.
2041 : AddressRange new_key;
2042 0 : new_key.start = cur.key().end;
2043 0 : new_key.end = 0;
2044 0 : if (!map->FindLeastGreaterThan(new_key, &cur)) return;
2045 : }
2046 : // Evict intersecting ranges.
2047 0 : while (cur.key().start < range.end) {
2048 0 : AddressRange old_range = cur.key();
2049 0 : JITCodeEntry* old_entry = cur.value();
2050 :
2051 0 : UnregisterCodeEntry(old_entry);
2052 : DestroyCodeEntry(old_entry);
2053 :
2054 0 : CHECK(map->Remove(old_range));
2055 0 : if (!map->FindLeastGreaterThan(old_range, &cur)) return;
2056 : }
2057 : }
2058 : }
2059 :
2060 :
2061 : // Insert the entry into the splay tree and register it with GDB.
2062 0 : static void AddJITCodeEntry(CodeMap* map, const AddressRange& range,
2063 : JITCodeEntry* entry, bool dump_if_enabled,
2064 : const char* name_hint) {
2065 : #if defined(DEBUG) && !V8_OS_WIN
2066 : static int file_num = 0;
2067 : if (FLAG_gdbjit_dump && dump_if_enabled) {
2068 : static const int kMaxFileNameSize = 64;
2069 : char file_name[64];
2070 :
2071 : SNPrintF(Vector<char>(file_name, kMaxFileNameSize), "/tmp/elfdump%s%d.o",
2072 : (name_hint != nullptr) ? name_hint : "", file_num++);
2073 : WriteBytes(file_name, reinterpret_cast<byte*>(entry->symfile_addr_),
2074 : static_cast<int>(entry->symfile_size_));
2075 : }
2076 : #endif
2077 :
2078 : CodeMap::Locator cur;
2079 0 : CHECK(map->Insert(range, &cur));
2080 : cur.set_value(entry);
2081 :
2082 0 : RegisterCodeEntry(entry);
2083 0 : }
2084 :
2085 0 : static void AddCode(const char* name, Code code, SharedFunctionInfo shared,
2086 : LineInfo* lineinfo) {
2087 : DisallowHeapAllocation no_gc;
2088 :
2089 0 : CodeMap* code_map = GetCodeMap();
2090 : AddressRange range;
2091 0 : range.start = code->address();
2092 0 : range.end = code->address() + code->CodeSize();
2093 0 : RemoveJITCodeEntries(code_map, range);
2094 :
2095 : CodeDescription code_desc(name, code, shared, lineinfo);
2096 :
2097 0 : if (!FLAG_gdbjit_full && !code_desc.IsLineInfoAvailable()) {
2098 0 : delete lineinfo;
2099 0 : return;
2100 : }
2101 :
2102 0 : AddUnwindInfo(&code_desc);
2103 : Isolate* isolate = code->GetIsolate();
2104 0 : JITCodeEntry* entry = CreateELFObject(&code_desc, isolate);
2105 :
2106 0 : delete lineinfo;
2107 :
2108 : const char* name_hint = nullptr;
2109 : bool should_dump = false;
2110 : if (FLAG_gdbjit_dump) {
2111 : if (strlen(FLAG_gdbjit_dump_filter) == 0) {
2112 : name_hint = name;
2113 : should_dump = true;
2114 : } else if (name != nullptr) {
2115 : name_hint = strstr(name, FLAG_gdbjit_dump_filter);
2116 : should_dump = (name_hint != nullptr);
2117 : }
2118 : }
2119 0 : AddJITCodeEntry(code_map, range, entry, should_dump, name_hint);
2120 : }
2121 :
2122 0 : void EventHandler(const v8::JitCodeEvent* event) {
2123 0 : if (!FLAG_gdbjit) return;
2124 0 : if (event->code_type != v8::JitCodeEvent::JIT_CODE) return;
2125 : base::MutexGuard lock_guard(mutex.Pointer());
2126 0 : switch (event->type) {
2127 : case v8::JitCodeEvent::CODE_ADDED: {
2128 0 : Address addr = reinterpret_cast<Address>(event->code_start);
2129 0 : Isolate* isolate = reinterpret_cast<Isolate*>(event->isolate);
2130 0 : Code code = isolate->heap()->GcSafeFindCodeForInnerPointer(addr);
2131 0 : LineInfo* lineinfo = GetLineInfo(addr);
2132 : EmbeddedVector<char, 256> buffer;
2133 : StringBuilder builder(buffer.start(), buffer.length());
2134 0 : builder.AddSubstring(event->name.str, static_cast<int>(event->name.len));
2135 : // It's called UnboundScript in the API but it's a SharedFunctionInfo.
2136 : SharedFunctionInfo shared = event->script.IsEmpty()
2137 : ? SharedFunctionInfo()
2138 0 : : *Utils::OpenHandle(*event->script);
2139 0 : AddCode(builder.Finalize(), code, shared, lineinfo);
2140 : break;
2141 : }
2142 : case v8::JitCodeEvent::CODE_MOVED:
2143 : // Enabling the GDB JIT interface should disable code compaction.
2144 0 : UNREACHABLE();
2145 : break;
2146 : case v8::JitCodeEvent::CODE_REMOVED:
2147 : // Do nothing. Instead, adding code causes eviction of any entry whose
2148 : // address range intersects the address range of the added code.
2149 : break;
2150 : case v8::JitCodeEvent::CODE_ADD_LINE_POS_INFO: {
2151 0 : LineInfo* line_info = reinterpret_cast<LineInfo*>(event->user_data);
2152 : line_info->SetPosition(static_cast<intptr_t>(event->line_info.offset),
2153 : static_cast<int>(event->line_info.pos),
2154 : event->line_info.position_type ==
2155 0 : v8::JitCodeEvent::STATEMENT_POSITION);
2156 : break;
2157 : }
2158 : case v8::JitCodeEvent::CODE_START_LINE_INFO_RECORDING: {
2159 : v8::JitCodeEvent* mutable_event = const_cast<v8::JitCodeEvent*>(event);
2160 0 : mutable_event->user_data = new LineInfo();
2161 0 : break;
2162 : }
2163 : case v8::JitCodeEvent::CODE_END_LINE_INFO_RECORDING: {
2164 0 : LineInfo* line_info = reinterpret_cast<LineInfo*>(event->user_data);
2165 0 : PutLineInfo(reinterpret_cast<Address>(event->code_start), line_info);
2166 0 : break;
2167 : }
2168 : }
2169 : }
2170 : #endif
2171 : } // namespace GDBJITInterface
2172 : } // namespace internal
2173 183867 : } // namespace v8
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