xref: /llvm-project/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp (revision c6c7bfc4d2bc37f55f57504c19d47deb7645dd76)
1 //===-- ObjectFileELF.cpp ------------------------------------- -*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "ObjectFileELF.h"
11 
12 #include <algorithm>
13 #include <cassert>
14 #include <unordered_map>
15 
16 #include "lldb/Core/FileSpecList.h"
17 #include "lldb/Core/Module.h"
18 #include "lldb/Core/ModuleSpec.h"
19 #include "lldb/Core/PluginManager.h"
20 #include "lldb/Core/Section.h"
21 #include "lldb/Symbol/DWARFCallFrameInfo.h"
22 #include "lldb/Symbol/SymbolContext.h"
23 #include "lldb/Target/SectionLoadList.h"
24 #include "lldb/Target/Target.h"
25 #include "lldb/Utility/ArchSpec.h"
26 #include "lldb/Utility/DataBufferHeap.h"
27 #include "lldb/Utility/Log.h"
28 #include "lldb/Utility/Status.h"
29 #include "lldb/Utility/Stream.h"
30 #include "lldb/Utility/Timer.h"
31 
32 #include "llvm/ADT/PointerUnion.h"
33 #include "llvm/ADT/StringRef.h"
34 #include "llvm/Object/Decompressor.h"
35 #include "llvm/Support/ARMBuildAttributes.h"
36 #include "llvm/Support/MathExtras.h"
37 #include "llvm/Support/MemoryBuffer.h"
38 #include "llvm/Support/MipsABIFlags.h"
39 
40 #define CASE_AND_STREAM(s, def, width)                                         \
41   case def:                                                                    \
42     s->Printf("%-*s", width, #def);                                            \
43     break;
44 
45 using namespace lldb;
46 using namespace lldb_private;
47 using namespace elf;
48 using namespace llvm::ELF;
49 
50 namespace {
51 
52 // ELF note owner definitions
53 const char *const LLDB_NT_OWNER_FREEBSD = "FreeBSD";
54 const char *const LLDB_NT_OWNER_GNU = "GNU";
55 const char *const LLDB_NT_OWNER_NETBSD = "NetBSD";
56 const char *const LLDB_NT_OWNER_OPENBSD = "OpenBSD";
57 const char *const LLDB_NT_OWNER_CSR = "csr";
58 const char *const LLDB_NT_OWNER_ANDROID = "Android";
59 const char *const LLDB_NT_OWNER_CORE = "CORE";
60 const char *const LLDB_NT_OWNER_LINUX = "LINUX";
61 
62 // ELF note type definitions
63 const elf_word LLDB_NT_FREEBSD_ABI_TAG = 0x01;
64 const elf_word LLDB_NT_FREEBSD_ABI_SIZE = 4;
65 
66 const elf_word LLDB_NT_GNU_ABI_TAG = 0x01;
67 const elf_word LLDB_NT_GNU_ABI_SIZE = 16;
68 
69 const elf_word LLDB_NT_GNU_BUILD_ID_TAG = 0x03;
70 
71 const elf_word LLDB_NT_NETBSD_ABI_TAG = 0x01;
72 const elf_word LLDB_NT_NETBSD_ABI_SIZE = 4;
73 
74 // GNU ABI note OS constants
75 const elf_word LLDB_NT_GNU_ABI_OS_LINUX = 0x00;
76 const elf_word LLDB_NT_GNU_ABI_OS_HURD = 0x01;
77 const elf_word LLDB_NT_GNU_ABI_OS_SOLARIS = 0x02;
78 
79 // LLDB_NT_OWNER_CORE and LLDB_NT_OWNER_LINUX note contants
80 #define NT_PRSTATUS 1
81 #define NT_PRFPREG 2
82 #define NT_PRPSINFO 3
83 #define NT_TASKSTRUCT 4
84 #define NT_AUXV 6
85 #define NT_SIGINFO 0x53494749
86 #define NT_FILE 0x46494c45
87 #define NT_PRXFPREG 0x46e62b7f
88 #define NT_PPC_VMX 0x100
89 #define NT_PPC_SPE 0x101
90 #define NT_PPC_VSX 0x102
91 #define NT_386_TLS 0x200
92 #define NT_386_IOPERM 0x201
93 #define NT_X86_XSTATE 0x202
94 #define NT_S390_HIGH_GPRS 0x300
95 #define NT_S390_TIMER 0x301
96 #define NT_S390_TODCMP 0x302
97 #define NT_S390_TODPREG 0x303
98 #define NT_S390_CTRS 0x304
99 #define NT_S390_PREFIX 0x305
100 #define NT_S390_LAST_BREAK 0x306
101 #define NT_S390_SYSTEM_CALL 0x307
102 #define NT_S390_TDB 0x308
103 #define NT_S390_VXRS_LOW 0x309
104 #define NT_S390_VXRS_HIGH 0x30a
105 #define NT_ARM_VFP 0x400
106 #define NT_ARM_TLS 0x401
107 #define NT_ARM_HW_BREAK 0x402
108 #define NT_ARM_HW_WATCH 0x403
109 #define NT_ARM_SYSTEM_CALL 0x404
110 #define NT_METAG_CBUF 0x500
111 #define NT_METAG_RPIPE 0x501
112 #define NT_METAG_TLS 0x502
113 
114 //===----------------------------------------------------------------------===//
115 /// @class ELFRelocation
116 /// Generic wrapper for ELFRel and ELFRela.
117 ///
118 /// This helper class allows us to parse both ELFRel and ELFRela relocation
119 /// entries in a generic manner.
120 class ELFRelocation {
121 public:
122   /// Constructs an ELFRelocation entry with a personality as given by @p
123   /// type.
124   ///
125   /// @param type Either DT_REL or DT_RELA.  Any other value is invalid.
126   ELFRelocation(unsigned type);
127 
128   ~ELFRelocation();
129 
130   bool Parse(const lldb_private::DataExtractor &data, lldb::offset_t *offset);
131 
132   static unsigned RelocType32(const ELFRelocation &rel);
133 
134   static unsigned RelocType64(const ELFRelocation &rel);
135 
136   static unsigned RelocSymbol32(const ELFRelocation &rel);
137 
138   static unsigned RelocSymbol64(const ELFRelocation &rel);
139 
140   static unsigned RelocOffset32(const ELFRelocation &rel);
141 
142   static unsigned RelocOffset64(const ELFRelocation &rel);
143 
144   static unsigned RelocAddend32(const ELFRelocation &rel);
145 
146   static unsigned RelocAddend64(const ELFRelocation &rel);
147 
148 private:
149   typedef llvm::PointerUnion<ELFRel *, ELFRela *> RelocUnion;
150 
151   RelocUnion reloc;
152 };
153 
154 ELFRelocation::ELFRelocation(unsigned type) {
155   if (type == DT_REL || type == SHT_REL)
156     reloc = new ELFRel();
157   else if (type == DT_RELA || type == SHT_RELA)
158     reloc = new ELFRela();
159   else {
160     assert(false && "unexpected relocation type");
161     reloc = static_cast<ELFRel *>(NULL);
162   }
163 }
164 
165 ELFRelocation::~ELFRelocation() {
166   if (reloc.is<ELFRel *>())
167     delete reloc.get<ELFRel *>();
168   else
169     delete reloc.get<ELFRela *>();
170 }
171 
172 bool ELFRelocation::Parse(const lldb_private::DataExtractor &data,
173                           lldb::offset_t *offset) {
174   if (reloc.is<ELFRel *>())
175     return reloc.get<ELFRel *>()->Parse(data, offset);
176   else
177     return reloc.get<ELFRela *>()->Parse(data, offset);
178 }
179 
180 unsigned ELFRelocation::RelocType32(const ELFRelocation &rel) {
181   if (rel.reloc.is<ELFRel *>())
182     return ELFRel::RelocType32(*rel.reloc.get<ELFRel *>());
183   else
184     return ELFRela::RelocType32(*rel.reloc.get<ELFRela *>());
185 }
186 
187 unsigned ELFRelocation::RelocType64(const ELFRelocation &rel) {
188   if (rel.reloc.is<ELFRel *>())
189     return ELFRel::RelocType64(*rel.reloc.get<ELFRel *>());
190   else
191     return ELFRela::RelocType64(*rel.reloc.get<ELFRela *>());
192 }
193 
194 unsigned ELFRelocation::RelocSymbol32(const ELFRelocation &rel) {
195   if (rel.reloc.is<ELFRel *>())
196     return ELFRel::RelocSymbol32(*rel.reloc.get<ELFRel *>());
197   else
198     return ELFRela::RelocSymbol32(*rel.reloc.get<ELFRela *>());
199 }
200 
201 unsigned ELFRelocation::RelocSymbol64(const ELFRelocation &rel) {
202   if (rel.reloc.is<ELFRel *>())
203     return ELFRel::RelocSymbol64(*rel.reloc.get<ELFRel *>());
204   else
205     return ELFRela::RelocSymbol64(*rel.reloc.get<ELFRela *>());
206 }
207 
208 unsigned ELFRelocation::RelocOffset32(const ELFRelocation &rel) {
209   if (rel.reloc.is<ELFRel *>())
210     return rel.reloc.get<ELFRel *>()->r_offset;
211   else
212     return rel.reloc.get<ELFRela *>()->r_offset;
213 }
214 
215 unsigned ELFRelocation::RelocOffset64(const ELFRelocation &rel) {
216   if (rel.reloc.is<ELFRel *>())
217     return rel.reloc.get<ELFRel *>()->r_offset;
218   else
219     return rel.reloc.get<ELFRela *>()->r_offset;
220 }
221 
222 unsigned ELFRelocation::RelocAddend32(const ELFRelocation &rel) {
223   if (rel.reloc.is<ELFRel *>())
224     return 0;
225   else
226     return rel.reloc.get<ELFRela *>()->r_addend;
227 }
228 
229 unsigned ELFRelocation::RelocAddend64(const ELFRelocation &rel) {
230   if (rel.reloc.is<ELFRel *>())
231     return 0;
232   else
233     return rel.reloc.get<ELFRela *>()->r_addend;
234 }
235 
236 } // end anonymous namespace
237 
238 bool ELFNote::Parse(const DataExtractor &data, lldb::offset_t *offset) {
239   // Read all fields.
240   if (data.GetU32(offset, &n_namesz, 3) == NULL)
241     return false;
242 
243   // The name field is required to be nul-terminated, and n_namesz includes the
244   // terminating nul in observed implementations (contrary to the ELF-64 spec).
245   // A special case is needed for cores generated by some older Linux versions,
246   // which write a note named "CORE" without a nul terminator and n_namesz = 4.
247   if (n_namesz == 4) {
248     char buf[4];
249     if (data.ExtractBytes(*offset, 4, data.GetByteOrder(), buf) != 4)
250       return false;
251     if (strncmp(buf, "CORE", 4) == 0) {
252       n_name = "CORE";
253       *offset += 4;
254       return true;
255     }
256   }
257 
258   const char *cstr = data.GetCStr(offset, llvm::alignTo(n_namesz, 4));
259   if (cstr == NULL) {
260     Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_SYMBOLS));
261     if (log)
262       log->Printf("Failed to parse note name lacking nul terminator");
263 
264     return false;
265   }
266   n_name = cstr;
267   return true;
268 }
269 
270 static uint32_t kalimbaVariantFromElfFlags(const elf::elf_word e_flags) {
271   const uint32_t dsp_rev = e_flags & 0xFF;
272   uint32_t kal_arch_variant = LLDB_INVALID_CPUTYPE;
273   switch (dsp_rev) {
274   // TODO(mg11) Support more variants
275   case 10:
276     kal_arch_variant = llvm::Triple::KalimbaSubArch_v3;
277     break;
278   case 14:
279     kal_arch_variant = llvm::Triple::KalimbaSubArch_v4;
280     break;
281   case 17:
282   case 20:
283     kal_arch_variant = llvm::Triple::KalimbaSubArch_v5;
284     break;
285   default:
286     break;
287   }
288   return kal_arch_variant;
289 }
290 
291 static uint32_t mipsVariantFromElfFlags (const elf::ELFHeader &header) {
292   const uint32_t mips_arch = header.e_flags & llvm::ELF::EF_MIPS_ARCH;
293   uint32_t endian = header.e_ident[EI_DATA];
294   uint32_t arch_variant = ArchSpec::eMIPSSubType_unknown;
295   uint32_t fileclass = header.e_ident[EI_CLASS];
296 
297   // If there aren't any elf flags available (e.g core elf file) then return
298   // default
299   // 32 or 64 bit arch (without any architecture revision) based on object file's class.
300   if (header.e_type == ET_CORE) {
301     switch (fileclass) {
302     case llvm::ELF::ELFCLASS32:
303       return (endian == ELFDATA2LSB) ? ArchSpec::eMIPSSubType_mips32el
304                                      : ArchSpec::eMIPSSubType_mips32;
305     case llvm::ELF::ELFCLASS64:
306       return (endian == ELFDATA2LSB) ? ArchSpec::eMIPSSubType_mips64el
307                                      : ArchSpec::eMIPSSubType_mips64;
308     default:
309       return arch_variant;
310     }
311   }
312 
313   switch (mips_arch) {
314   case llvm::ELF::EF_MIPS_ARCH_1:
315   case llvm::ELF::EF_MIPS_ARCH_2:
316   case llvm::ELF::EF_MIPS_ARCH_32:
317     return (endian == ELFDATA2LSB) ? ArchSpec::eMIPSSubType_mips32el
318                                    : ArchSpec::eMIPSSubType_mips32;
319   case llvm::ELF::EF_MIPS_ARCH_32R2:
320     return (endian == ELFDATA2LSB) ? ArchSpec::eMIPSSubType_mips32r2el
321                                    : ArchSpec::eMIPSSubType_mips32r2;
322   case llvm::ELF::EF_MIPS_ARCH_32R6:
323     return (endian == ELFDATA2LSB) ? ArchSpec::eMIPSSubType_mips32r6el
324                                    : ArchSpec::eMIPSSubType_mips32r6;
325   case llvm::ELF::EF_MIPS_ARCH_3:
326   case llvm::ELF::EF_MIPS_ARCH_4:
327   case llvm::ELF::EF_MIPS_ARCH_5:
328   case llvm::ELF::EF_MIPS_ARCH_64:
329     return (endian == ELFDATA2LSB) ? ArchSpec::eMIPSSubType_mips64el
330                                    : ArchSpec::eMIPSSubType_mips64;
331   case llvm::ELF::EF_MIPS_ARCH_64R2:
332     return (endian == ELFDATA2LSB) ? ArchSpec::eMIPSSubType_mips64r2el
333                                    : ArchSpec::eMIPSSubType_mips64r2;
334   case llvm::ELF::EF_MIPS_ARCH_64R6:
335     return (endian == ELFDATA2LSB) ? ArchSpec::eMIPSSubType_mips64r6el
336                                    : ArchSpec::eMIPSSubType_mips64r6;
337   default:
338     break;
339   }
340 
341   return arch_variant;
342 }
343 
344 static uint32_t subTypeFromElfHeader(const elf::ELFHeader &header) {
345   if (header.e_machine == llvm::ELF::EM_MIPS)
346     return mipsVariantFromElfFlags(header);
347 
348   return llvm::ELF::EM_CSR_KALIMBA == header.e_machine
349              ? kalimbaVariantFromElfFlags(header.e_flags)
350              : LLDB_INVALID_CPUTYPE;
351 }
352 
353 //! The kalimba toolchain identifies a code section as being
354 //! one with the SHT_PROGBITS set in the section sh_type and the top
355 //! bit in the 32-bit address field set.
356 static lldb::SectionType
357 kalimbaSectionType(const elf::ELFHeader &header,
358                    const elf::ELFSectionHeader &sect_hdr) {
359   if (llvm::ELF::EM_CSR_KALIMBA != header.e_machine) {
360     return eSectionTypeOther;
361   }
362 
363   if (llvm::ELF::SHT_NOBITS == sect_hdr.sh_type) {
364     return eSectionTypeZeroFill;
365   }
366 
367   if (llvm::ELF::SHT_PROGBITS == sect_hdr.sh_type) {
368     const lldb::addr_t KAL_CODE_BIT = 1 << 31;
369     return KAL_CODE_BIT & sect_hdr.sh_addr ? eSectionTypeCode
370                                            : eSectionTypeData;
371   }
372 
373   return eSectionTypeOther;
374 }
375 
376 // Arbitrary constant used as UUID prefix for core files.
377 const uint32_t ObjectFileELF::g_core_uuid_magic(0xE210C);
378 
379 //------------------------------------------------------------------
380 // Static methods.
381 //------------------------------------------------------------------
382 void ObjectFileELF::Initialize() {
383   PluginManager::RegisterPlugin(GetPluginNameStatic(),
384                                 GetPluginDescriptionStatic(), CreateInstance,
385                                 CreateMemoryInstance, GetModuleSpecifications);
386 }
387 
388 void ObjectFileELF::Terminate() {
389   PluginManager::UnregisterPlugin(CreateInstance);
390 }
391 
392 lldb_private::ConstString ObjectFileELF::GetPluginNameStatic() {
393   static ConstString g_name("elf");
394   return g_name;
395 }
396 
397 const char *ObjectFileELF::GetPluginDescriptionStatic() {
398   return "ELF object file reader.";
399 }
400 
401 ObjectFile *ObjectFileELF::CreateInstance(const lldb::ModuleSP &module_sp,
402                                           DataBufferSP &data_sp,
403                                           lldb::offset_t data_offset,
404                                           const lldb_private::FileSpec *file,
405                                           lldb::offset_t file_offset,
406                                           lldb::offset_t length) {
407   if (!data_sp) {
408     data_sp = MapFileData(*file, length, file_offset);
409     if (!data_sp)
410       return nullptr;
411     data_offset = 0;
412   }
413 
414   assert(data_sp);
415 
416   if (data_sp->GetByteSize() <= (llvm::ELF::EI_NIDENT + data_offset))
417     return nullptr;
418 
419   const uint8_t *magic = data_sp->GetBytes() + data_offset;
420   if (!ELFHeader::MagicBytesMatch(magic))
421     return nullptr;
422 
423   // Update the data to contain the entire file if it doesn't already
424   if (data_sp->GetByteSize() < length) {
425     data_sp = MapFileData(*file, length, file_offset);
426     if (!data_sp)
427       return nullptr;
428     data_offset = 0;
429     magic = data_sp->GetBytes();
430   }
431 
432   unsigned address_size = ELFHeader::AddressSizeInBytes(magic);
433   if (address_size == 4 || address_size == 8) {
434     std::unique_ptr<ObjectFileELF> objfile_ap(new ObjectFileELF(
435         module_sp, data_sp, data_offset, file, file_offset, length));
436     ArchSpec spec;
437     if (objfile_ap->GetArchitecture(spec) &&
438         objfile_ap->SetModulesArchitecture(spec))
439       return objfile_ap.release();
440   }
441 
442   return NULL;
443 }
444 
445 ObjectFile *ObjectFileELF::CreateMemoryInstance(
446     const lldb::ModuleSP &module_sp, DataBufferSP &data_sp,
447     const lldb::ProcessSP &process_sp, lldb::addr_t header_addr) {
448   if (data_sp && data_sp->GetByteSize() > (llvm::ELF::EI_NIDENT)) {
449     const uint8_t *magic = data_sp->GetBytes();
450     if (ELFHeader::MagicBytesMatch(magic)) {
451       unsigned address_size = ELFHeader::AddressSizeInBytes(magic);
452       if (address_size == 4 || address_size == 8) {
453         std::unique_ptr<ObjectFileELF> objfile_ap(
454             new ObjectFileELF(module_sp, data_sp, process_sp, header_addr));
455         ArchSpec spec;
456         if (objfile_ap->GetArchitecture(spec) &&
457             objfile_ap->SetModulesArchitecture(spec))
458           return objfile_ap.release();
459       }
460     }
461   }
462   return NULL;
463 }
464 
465 bool ObjectFileELF::MagicBytesMatch(DataBufferSP &data_sp,
466                                     lldb::addr_t data_offset,
467                                     lldb::addr_t data_length) {
468   if (data_sp &&
469       data_sp->GetByteSize() > (llvm::ELF::EI_NIDENT + data_offset)) {
470     const uint8_t *magic = data_sp->GetBytes() + data_offset;
471     return ELFHeader::MagicBytesMatch(magic);
472   }
473   return false;
474 }
475 
476 /*
477  * crc function from http://svnweb.freebsd.org/base/head/sys/libkern/crc32.c
478  *
479  *   COPYRIGHT (C) 1986 Gary S. Brown. You may use this program, or
480  *   code or tables extracted from it, as desired without restriction.
481  */
482 static uint32_t calc_crc32(uint32_t crc, const void *buf, size_t size) {
483   static const uint32_t g_crc32_tab[] = {
484       0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f,
485       0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988,
486       0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91, 0x1db71064, 0x6ab020f2,
487       0xf3b97148, 0x84be41de, 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
488       0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9,
489       0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172,
490       0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, 0x35b5a8fa, 0x42b2986c,
491       0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
492       0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423,
493       0xcfba9599, 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
494       0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190, 0x01db7106,
495       0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
496       0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d,
497       0x91646c97, 0xe6635c01, 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e,
498       0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950,
499       0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
500       0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7,
501       0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0,
502       0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa,
503       0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
504       0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81,
505       0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a,
506       0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683, 0xe3630b12, 0x94643b84,
507       0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
508       0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb,
509       0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc,
510       0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, 0xd6d6a3e8, 0xa1d1937e,
511       0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
512       0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55,
513       0x316e8eef, 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
514       0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, 0xb2bd0b28,
515       0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
516       0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f,
517       0x72076785, 0x05005713, 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38,
518       0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242,
519       0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
520       0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69,
521       0x616bffd3, 0x166ccf45, 0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2,
522       0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc,
523       0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
524       0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693,
525       0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94,
526       0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d};
527   const uint8_t *p = (const uint8_t *)buf;
528 
529   crc = crc ^ ~0U;
530   while (size--)
531     crc = g_crc32_tab[(crc ^ *p++) & 0xFF] ^ (crc >> 8);
532   return crc ^ ~0U;
533 }
534 
535 static uint32_t calc_gnu_debuglink_crc32(const void *buf, size_t size) {
536   return calc_crc32(0U, buf, size);
537 }
538 
539 uint32_t ObjectFileELF::CalculateELFNotesSegmentsCRC32(
540     const ProgramHeaderColl &program_headers, DataExtractor &object_data) {
541   typedef ProgramHeaderCollConstIter Iter;
542 
543   uint32_t core_notes_crc = 0;
544 
545   for (Iter I = program_headers.begin(); I != program_headers.end(); ++I) {
546     if (I->p_type == llvm::ELF::PT_NOTE) {
547       const elf_off ph_offset = I->p_offset;
548       const size_t ph_size = I->p_filesz;
549 
550       DataExtractor segment_data;
551       if (segment_data.SetData(object_data, ph_offset, ph_size) != ph_size) {
552         // The ELF program header contained incorrect data, probably corefile
553         // is incomplete or corrupted.
554         break;
555       }
556 
557       core_notes_crc = calc_crc32(core_notes_crc, segment_data.GetDataStart(),
558                                   segment_data.GetByteSize());
559     }
560   }
561 
562   return core_notes_crc;
563 }
564 
565 static const char *OSABIAsCString(unsigned char osabi_byte) {
566 #define _MAKE_OSABI_CASE(x)                                                    \
567   case x:                                                                      \
568     return #x
569   switch (osabi_byte) {
570     _MAKE_OSABI_CASE(ELFOSABI_NONE);
571     _MAKE_OSABI_CASE(ELFOSABI_HPUX);
572     _MAKE_OSABI_CASE(ELFOSABI_NETBSD);
573     _MAKE_OSABI_CASE(ELFOSABI_GNU);
574     _MAKE_OSABI_CASE(ELFOSABI_HURD);
575     _MAKE_OSABI_CASE(ELFOSABI_SOLARIS);
576     _MAKE_OSABI_CASE(ELFOSABI_AIX);
577     _MAKE_OSABI_CASE(ELFOSABI_IRIX);
578     _MAKE_OSABI_CASE(ELFOSABI_FREEBSD);
579     _MAKE_OSABI_CASE(ELFOSABI_TRU64);
580     _MAKE_OSABI_CASE(ELFOSABI_MODESTO);
581     _MAKE_OSABI_CASE(ELFOSABI_OPENBSD);
582     _MAKE_OSABI_CASE(ELFOSABI_OPENVMS);
583     _MAKE_OSABI_CASE(ELFOSABI_NSK);
584     _MAKE_OSABI_CASE(ELFOSABI_AROS);
585     _MAKE_OSABI_CASE(ELFOSABI_FENIXOS);
586     _MAKE_OSABI_CASE(ELFOSABI_C6000_ELFABI);
587     _MAKE_OSABI_CASE(ELFOSABI_C6000_LINUX);
588     _MAKE_OSABI_CASE(ELFOSABI_ARM);
589     _MAKE_OSABI_CASE(ELFOSABI_STANDALONE);
590   default:
591     return "<unknown-osabi>";
592   }
593 #undef _MAKE_OSABI_CASE
594 }
595 
596 //
597 // WARNING : This function is being deprecated
598 // It's functionality has moved to ArchSpec::SetArchitecture This function is
599 // only being kept to validate the move.
600 //
601 // TODO : Remove this function
602 static bool GetOsFromOSABI(unsigned char osabi_byte,
603                            llvm::Triple::OSType &ostype) {
604   switch (osabi_byte) {
605   case ELFOSABI_AIX:
606     ostype = llvm::Triple::OSType::AIX;
607     break;
608   case ELFOSABI_FREEBSD:
609     ostype = llvm::Triple::OSType::FreeBSD;
610     break;
611   case ELFOSABI_GNU:
612     ostype = llvm::Triple::OSType::Linux;
613     break;
614   case ELFOSABI_NETBSD:
615     ostype = llvm::Triple::OSType::NetBSD;
616     break;
617   case ELFOSABI_OPENBSD:
618     ostype = llvm::Triple::OSType::OpenBSD;
619     break;
620   case ELFOSABI_SOLARIS:
621     ostype = llvm::Triple::OSType::Solaris;
622     break;
623   default:
624     ostype = llvm::Triple::OSType::UnknownOS;
625   }
626   return ostype != llvm::Triple::OSType::UnknownOS;
627 }
628 
629 size_t ObjectFileELF::GetModuleSpecifications(
630     const lldb_private::FileSpec &file, lldb::DataBufferSP &data_sp,
631     lldb::offset_t data_offset, lldb::offset_t file_offset,
632     lldb::offset_t length, lldb_private::ModuleSpecList &specs) {
633   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_MODULES));
634 
635   const size_t initial_count = specs.GetSize();
636 
637   if (ObjectFileELF::MagicBytesMatch(data_sp, 0, data_sp->GetByteSize())) {
638     DataExtractor data;
639     data.SetData(data_sp);
640     elf::ELFHeader header;
641     lldb::offset_t header_offset = data_offset;
642     if (header.Parse(data, &header_offset)) {
643       if (data_sp) {
644         ModuleSpec spec(file);
645 
646         const uint32_t sub_type = subTypeFromElfHeader(header);
647         spec.GetArchitecture().SetArchitecture(
648             eArchTypeELF, header.e_machine, sub_type, header.e_ident[EI_OSABI]);
649 
650         if (spec.GetArchitecture().IsValid()) {
651           llvm::Triple::OSType ostype;
652           llvm::Triple::VendorType vendor;
653           llvm::Triple::OSType spec_ostype =
654               spec.GetArchitecture().GetTriple().getOS();
655 
656           if (log)
657             log->Printf("ObjectFileELF::%s file '%s' module OSABI: %s",
658                         __FUNCTION__, file.GetPath().c_str(),
659                         OSABIAsCString(header.e_ident[EI_OSABI]));
660 
661           // SetArchitecture should have set the vendor to unknown
662           vendor = spec.GetArchitecture().GetTriple().getVendor();
663           assert(vendor == llvm::Triple::UnknownVendor);
664           UNUSED_IF_ASSERT_DISABLED(vendor);
665 
666           //
667           // Validate it is ok to remove GetOsFromOSABI
668           GetOsFromOSABI(header.e_ident[EI_OSABI], ostype);
669           assert(spec_ostype == ostype);
670           if (spec_ostype != llvm::Triple::OSType::UnknownOS) {
671             if (log)
672               log->Printf("ObjectFileELF::%s file '%s' set ELF module OS type "
673                           "from ELF header OSABI.",
674                           __FUNCTION__, file.GetPath().c_str());
675           }
676 
677           data_sp = MapFileData(file, -1, file_offset);
678           if (data_sp)
679             data.SetData(data_sp);
680           // In case there is header extension in the section #0, the header we
681           // parsed above could have sentinel values for e_phnum, e_shnum, and
682           // e_shstrndx.  In this case we need to reparse the header with a
683           // bigger data source to get the actual values.
684           if (header.HasHeaderExtension()) {
685             lldb::offset_t header_offset = data_offset;
686             header.Parse(data, &header_offset);
687           }
688 
689           uint32_t gnu_debuglink_crc = 0;
690           std::string gnu_debuglink_file;
691           SectionHeaderColl section_headers;
692           lldb_private::UUID &uuid = spec.GetUUID();
693 
694           GetSectionHeaderInfo(section_headers, data, header, uuid,
695                                gnu_debuglink_file, gnu_debuglink_crc,
696                                spec.GetArchitecture());
697 
698           llvm::Triple &spec_triple = spec.GetArchitecture().GetTriple();
699 
700           if (log)
701             log->Printf("ObjectFileELF::%s file '%s' module set to triple: %s "
702                         "(architecture %s)",
703                         __FUNCTION__, file.GetPath().c_str(),
704                         spec_triple.getTriple().c_str(),
705                         spec.GetArchitecture().GetArchitectureName());
706 
707           if (!uuid.IsValid()) {
708             uint32_t core_notes_crc = 0;
709 
710             if (!gnu_debuglink_crc) {
711               static Timer::Category func_cat(LLVM_PRETTY_FUNCTION);
712               lldb_private::Timer scoped_timer(
713                   func_cat,
714                   "Calculating module crc32 %s with size %" PRIu64 " KiB",
715                   file.GetLastPathComponent().AsCString(),
716                   (file.GetByteSize() - file_offset) / 1024);
717 
718               // For core files - which usually don't happen to have a
719               // gnu_debuglink, and are pretty bulky - calculating whole
720               // contents crc32 would be too much of luxury.  Thus we will need
721               // to fallback to something simpler.
722               if (header.e_type == llvm::ELF::ET_CORE) {
723                 ProgramHeaderColl program_headers;
724                 GetProgramHeaderInfo(program_headers, data, header);
725 
726                 core_notes_crc =
727                     CalculateELFNotesSegmentsCRC32(program_headers, data);
728               } else {
729                 gnu_debuglink_crc = calc_gnu_debuglink_crc32(
730                     data.GetDataStart(), data.GetByteSize());
731               }
732             }
733             using u32le = llvm::support::ulittle32_t;
734             if (gnu_debuglink_crc) {
735               // Use 4 bytes of crc from the .gnu_debuglink section.
736               u32le data(gnu_debuglink_crc);
737               uuid = UUID::fromData(&data, sizeof(data));
738             } else if (core_notes_crc) {
739               // Use 8 bytes - first 4 bytes for *magic* prefix, mainly to make
740               // it look different form .gnu_debuglink crc followed by 4 bytes
741               // of note segments crc.
742               u32le data[] = {u32le(g_core_uuid_magic), u32le(core_notes_crc)};
743               uuid = UUID::fromData(data, sizeof(data));
744             }
745           }
746 
747           specs.Append(spec);
748         }
749       }
750     }
751   }
752 
753   return specs.GetSize() - initial_count;
754 }
755 
756 //------------------------------------------------------------------
757 // PluginInterface protocol
758 //------------------------------------------------------------------
759 lldb_private::ConstString ObjectFileELF::GetPluginName() {
760   return GetPluginNameStatic();
761 }
762 
763 uint32_t ObjectFileELF::GetPluginVersion() { return m_plugin_version; }
764 //------------------------------------------------------------------
765 // ObjectFile protocol
766 //------------------------------------------------------------------
767 
768 ObjectFileELF::ObjectFileELF(const lldb::ModuleSP &module_sp,
769                              DataBufferSP &data_sp, lldb::offset_t data_offset,
770                              const FileSpec *file, lldb::offset_t file_offset,
771                              lldb::offset_t length)
772     : ObjectFile(module_sp, file, file_offset, length, data_sp, data_offset),
773       m_header(), m_uuid(), m_gnu_debuglink_file(), m_gnu_debuglink_crc(0),
774       m_program_headers(), m_section_headers(), m_dynamic_symbols(),
775       m_filespec_ap(), m_entry_point_address(), m_arch_spec() {
776   if (file)
777     m_file = *file;
778   ::memset(&m_header, 0, sizeof(m_header));
779 }
780 
781 ObjectFileELF::ObjectFileELF(const lldb::ModuleSP &module_sp,
782                              DataBufferSP &header_data_sp,
783                              const lldb::ProcessSP &process_sp,
784                              addr_t header_addr)
785     : ObjectFile(module_sp, process_sp, header_addr, header_data_sp),
786       m_header(), m_uuid(), m_gnu_debuglink_file(), m_gnu_debuglink_crc(0),
787       m_program_headers(), m_section_headers(), m_dynamic_symbols(),
788       m_filespec_ap(), m_entry_point_address(), m_arch_spec() {
789   ::memset(&m_header, 0, sizeof(m_header));
790 }
791 
792 ObjectFileELF::~ObjectFileELF() {}
793 
794 bool ObjectFileELF::IsExecutable() const {
795   return ((m_header.e_type & ET_EXEC) != 0) || (m_header.e_entry != 0);
796 }
797 
798 bool ObjectFileELF::SetLoadAddress(Target &target, lldb::addr_t value,
799                                    bool value_is_offset) {
800   ModuleSP module_sp = GetModule();
801   if (module_sp) {
802     size_t num_loaded_sections = 0;
803     SectionList *section_list = GetSectionList();
804     if (section_list) {
805       if (!value_is_offset) {
806         bool found_offset = false;
807         for (size_t i = 1, count = GetProgramHeaderCount(); i <= count; ++i) {
808           const elf::ELFProgramHeader *header = GetProgramHeaderByIndex(i);
809           if (header == nullptr)
810             continue;
811 
812           if (header->p_type != PT_LOAD || header->p_offset != 0)
813             continue;
814 
815           value = value - header->p_vaddr;
816           found_offset = true;
817           break;
818         }
819         if (!found_offset)
820           return false;
821       }
822 
823       const size_t num_sections = section_list->GetSize();
824       size_t sect_idx = 0;
825 
826       for (sect_idx = 0; sect_idx < num_sections; ++sect_idx) {
827         // Iterate through the object file sections to find all of the sections
828         // that have SHF_ALLOC in their flag bits.
829         SectionSP section_sp(section_list->GetSectionAtIndex(sect_idx));
830         if (section_sp && section_sp->Test(SHF_ALLOC)) {
831           lldb::addr_t load_addr = section_sp->GetFileAddress();
832           // We don't want to update the load address of a section with type
833           // eSectionTypeAbsoluteAddress as they already have the absolute load
834           // address already specified
835           if (section_sp->GetType() != eSectionTypeAbsoluteAddress)
836             load_addr += value;
837 
838           // On 32-bit systems the load address have to fit into 4 bytes. The
839           // rest of the bytes are the overflow from the addition.
840           if (GetAddressByteSize() == 4)
841             load_addr &= 0xFFFFFFFF;
842 
843           if (target.GetSectionLoadList().SetSectionLoadAddress(section_sp,
844                                                                 load_addr))
845             ++num_loaded_sections;
846         }
847       }
848       return num_loaded_sections > 0;
849     }
850   }
851   return false;
852 }
853 
854 ByteOrder ObjectFileELF::GetByteOrder() const {
855   if (m_header.e_ident[EI_DATA] == ELFDATA2MSB)
856     return eByteOrderBig;
857   if (m_header.e_ident[EI_DATA] == ELFDATA2LSB)
858     return eByteOrderLittle;
859   return eByteOrderInvalid;
860 }
861 
862 uint32_t ObjectFileELF::GetAddressByteSize() const {
863   return m_data.GetAddressByteSize();
864 }
865 
866 AddressClass ObjectFileELF::GetAddressClass(addr_t file_addr) {
867   Symtab *symtab = GetSymtab();
868   if (!symtab)
869     return AddressClass::eUnknown;
870 
871   // The address class is determined based on the symtab. Ask it from the
872   // object file what contains the symtab information.
873   ObjectFile *symtab_objfile = symtab->GetObjectFile();
874   if (symtab_objfile != nullptr && symtab_objfile != this)
875     return symtab_objfile->GetAddressClass(file_addr);
876 
877   auto res = ObjectFile::GetAddressClass(file_addr);
878   if (res != AddressClass::eCode)
879     return res;
880 
881   auto ub = m_address_class_map.upper_bound(file_addr);
882   if (ub == m_address_class_map.begin()) {
883     // No entry in the address class map before the address. Return default
884     // address class for an address in a code section.
885     return AddressClass::eCode;
886   }
887 
888   // Move iterator to the address class entry preceding address
889   --ub;
890 
891   return ub->second;
892 }
893 
894 size_t ObjectFileELF::SectionIndex(const SectionHeaderCollIter &I) {
895   return std::distance(m_section_headers.begin(), I) + 1u;
896 }
897 
898 size_t ObjectFileELF::SectionIndex(const SectionHeaderCollConstIter &I) const {
899   return std::distance(m_section_headers.begin(), I) + 1u;
900 }
901 
902 bool ObjectFileELF::ParseHeader() {
903   lldb::offset_t offset = 0;
904   return m_header.Parse(m_data, &offset);
905 }
906 
907 bool ObjectFileELF::GetUUID(lldb_private::UUID *uuid) {
908   // Need to parse the section list to get the UUIDs, so make sure that's been
909   // done.
910   if (!ParseSectionHeaders() && GetType() != ObjectFile::eTypeCoreFile)
911     return false;
912 
913   using u32le = llvm::support::ulittle32_t;
914   if (m_uuid.IsValid()) {
915     // We have the full build id uuid.
916     *uuid = m_uuid;
917     return true;
918   } else if (GetType() == ObjectFile::eTypeCoreFile) {
919     uint32_t core_notes_crc = 0;
920 
921     if (!ParseProgramHeaders())
922       return false;
923 
924     core_notes_crc = CalculateELFNotesSegmentsCRC32(m_program_headers, m_data);
925 
926     if (core_notes_crc) {
927       // Use 8 bytes - first 4 bytes for *magic* prefix, mainly to make it look
928       // different form .gnu_debuglink crc - followed by 4 bytes of note
929       // segments crc.
930       u32le data[] = {u32le(g_core_uuid_magic), u32le(core_notes_crc)};
931       m_uuid = UUID::fromData(data, sizeof(data));
932     }
933   } else {
934     if (!m_gnu_debuglink_crc)
935       m_gnu_debuglink_crc =
936           calc_gnu_debuglink_crc32(m_data.GetDataStart(), m_data.GetByteSize());
937     if (m_gnu_debuglink_crc) {
938       // Use 4 bytes of crc from the .gnu_debuglink section.
939       u32le data(m_gnu_debuglink_crc);
940       m_uuid = UUID::fromData(&data, sizeof(data));
941     }
942   }
943 
944   if (m_uuid.IsValid()) {
945     *uuid = m_uuid;
946     return true;
947   }
948 
949   return false;
950 }
951 
952 lldb_private::FileSpecList ObjectFileELF::GetDebugSymbolFilePaths() {
953   FileSpecList file_spec_list;
954 
955   if (!m_gnu_debuglink_file.empty()) {
956     FileSpec file_spec(m_gnu_debuglink_file, false);
957     file_spec_list.Append(file_spec);
958   }
959   return file_spec_list;
960 }
961 
962 uint32_t ObjectFileELF::GetDependentModules(FileSpecList &files) {
963   size_t num_modules = ParseDependentModules();
964   uint32_t num_specs = 0;
965 
966   for (unsigned i = 0; i < num_modules; ++i) {
967     if (files.AppendIfUnique(m_filespec_ap->GetFileSpecAtIndex(i)))
968       num_specs++;
969   }
970 
971   return num_specs;
972 }
973 
974 Address ObjectFileELF::GetImageInfoAddress(Target *target) {
975   if (!ParseDynamicSymbols())
976     return Address();
977 
978   SectionList *section_list = GetSectionList();
979   if (!section_list)
980     return Address();
981 
982   // Find the SHT_DYNAMIC (.dynamic) section.
983   SectionSP dynsym_section_sp(
984       section_list->FindSectionByType(eSectionTypeELFDynamicLinkInfo, true));
985   if (!dynsym_section_sp)
986     return Address();
987   assert(dynsym_section_sp->GetObjectFile() == this);
988 
989   user_id_t dynsym_id = dynsym_section_sp->GetID();
990   const ELFSectionHeaderInfo *dynsym_hdr = GetSectionHeaderByIndex(dynsym_id);
991   if (!dynsym_hdr)
992     return Address();
993 
994   for (size_t i = 0; i < m_dynamic_symbols.size(); ++i) {
995     ELFDynamic &symbol = m_dynamic_symbols[i];
996 
997     if (symbol.d_tag == DT_DEBUG) {
998       // Compute the offset as the number of previous entries plus the size of
999       // d_tag.
1000       addr_t offset = i * dynsym_hdr->sh_entsize + GetAddressByteSize();
1001       return Address(dynsym_section_sp, offset);
1002     }
1003     // MIPS executables uses DT_MIPS_RLD_MAP_REL to support PIE. DT_MIPS_RLD_MAP
1004     // exists in non-PIE.
1005     else if ((symbol.d_tag == DT_MIPS_RLD_MAP ||
1006               symbol.d_tag == DT_MIPS_RLD_MAP_REL) &&
1007              target) {
1008       addr_t offset = i * dynsym_hdr->sh_entsize + GetAddressByteSize();
1009       addr_t dyn_base = dynsym_section_sp->GetLoadBaseAddress(target);
1010       if (dyn_base == LLDB_INVALID_ADDRESS)
1011         return Address();
1012 
1013       Status error;
1014       if (symbol.d_tag == DT_MIPS_RLD_MAP) {
1015         // DT_MIPS_RLD_MAP tag stores an absolute address of the debug pointer.
1016         Address addr;
1017         if (target->ReadPointerFromMemory(dyn_base + offset, false, error,
1018                                           addr))
1019           return addr;
1020       }
1021       if (symbol.d_tag == DT_MIPS_RLD_MAP_REL) {
1022         // DT_MIPS_RLD_MAP_REL tag stores the offset to the debug pointer,
1023         // relative to the address of the tag.
1024         uint64_t rel_offset;
1025         rel_offset = target->ReadUnsignedIntegerFromMemory(
1026             dyn_base + offset, false, GetAddressByteSize(), UINT64_MAX, error);
1027         if (error.Success() && rel_offset != UINT64_MAX) {
1028           Address addr;
1029           addr_t debug_ptr_address =
1030               dyn_base + (offset - GetAddressByteSize()) + rel_offset;
1031           addr.SetOffset(debug_ptr_address);
1032           return addr;
1033         }
1034       }
1035     }
1036   }
1037 
1038   return Address();
1039 }
1040 
1041 lldb_private::Address ObjectFileELF::GetEntryPointAddress() {
1042   if (m_entry_point_address.IsValid())
1043     return m_entry_point_address;
1044 
1045   if (!ParseHeader() || !IsExecutable())
1046     return m_entry_point_address;
1047 
1048   SectionList *section_list = GetSectionList();
1049   addr_t offset = m_header.e_entry;
1050 
1051   if (!section_list)
1052     m_entry_point_address.SetOffset(offset);
1053   else
1054     m_entry_point_address.ResolveAddressUsingFileSections(offset, section_list);
1055   return m_entry_point_address;
1056 }
1057 
1058 //----------------------------------------------------------------------
1059 // ParseDependentModules
1060 //----------------------------------------------------------------------
1061 size_t ObjectFileELF::ParseDependentModules() {
1062   if (m_filespec_ap.get())
1063     return m_filespec_ap->GetSize();
1064 
1065   m_filespec_ap.reset(new FileSpecList());
1066 
1067   if (!ParseSectionHeaders())
1068     return 0;
1069 
1070   SectionList *section_list = GetSectionList();
1071   if (!section_list)
1072     return 0;
1073 
1074   // Find the SHT_DYNAMIC section.
1075   Section *dynsym =
1076       section_list->FindSectionByType(eSectionTypeELFDynamicLinkInfo, true)
1077           .get();
1078   if (!dynsym)
1079     return 0;
1080   assert(dynsym->GetObjectFile() == this);
1081 
1082   const ELFSectionHeaderInfo *header = GetSectionHeaderByIndex(dynsym->GetID());
1083   if (!header)
1084     return 0;
1085   // sh_link: section header index of string table used by entries in the
1086   // section.
1087   Section *dynstr = section_list->FindSectionByID(header->sh_link + 1).get();
1088   if (!dynstr)
1089     return 0;
1090 
1091   DataExtractor dynsym_data;
1092   DataExtractor dynstr_data;
1093   if (ReadSectionData(dynsym, dynsym_data) &&
1094       ReadSectionData(dynstr, dynstr_data)) {
1095     ELFDynamic symbol;
1096     const lldb::offset_t section_size = dynsym_data.GetByteSize();
1097     lldb::offset_t offset = 0;
1098 
1099     // The only type of entries we are concerned with are tagged DT_NEEDED,
1100     // yielding the name of a required library.
1101     while (offset < section_size) {
1102       if (!symbol.Parse(dynsym_data, &offset))
1103         break;
1104 
1105       if (symbol.d_tag != DT_NEEDED)
1106         continue;
1107 
1108       uint32_t str_index = static_cast<uint32_t>(symbol.d_val);
1109       const char *lib_name = dynstr_data.PeekCStr(str_index);
1110       m_filespec_ap->Append(FileSpec(lib_name, true));
1111     }
1112   }
1113 
1114   return m_filespec_ap->GetSize();
1115 }
1116 
1117 //----------------------------------------------------------------------
1118 // GetProgramHeaderInfo
1119 //----------------------------------------------------------------------
1120 size_t ObjectFileELF::GetProgramHeaderInfo(ProgramHeaderColl &program_headers,
1121                                            DataExtractor &object_data,
1122                                            const ELFHeader &header) {
1123   // We have already parsed the program headers
1124   if (!program_headers.empty())
1125     return program_headers.size();
1126 
1127   // If there are no program headers to read we are done.
1128   if (header.e_phnum == 0)
1129     return 0;
1130 
1131   program_headers.resize(header.e_phnum);
1132   if (program_headers.size() != header.e_phnum)
1133     return 0;
1134 
1135   const size_t ph_size = header.e_phnum * header.e_phentsize;
1136   const elf_off ph_offset = header.e_phoff;
1137   DataExtractor data;
1138   if (data.SetData(object_data, ph_offset, ph_size) != ph_size)
1139     return 0;
1140 
1141   uint32_t idx;
1142   lldb::offset_t offset;
1143   for (idx = 0, offset = 0; idx < header.e_phnum; ++idx) {
1144     if (program_headers[idx].Parse(data, &offset) == false)
1145       break;
1146   }
1147 
1148   if (idx < program_headers.size())
1149     program_headers.resize(idx);
1150 
1151   return program_headers.size();
1152 }
1153 
1154 //----------------------------------------------------------------------
1155 // ParseProgramHeaders
1156 //----------------------------------------------------------------------
1157 size_t ObjectFileELF::ParseProgramHeaders() {
1158   return GetProgramHeaderInfo(m_program_headers, m_data, m_header);
1159 }
1160 
1161 lldb_private::Status
1162 ObjectFileELF::RefineModuleDetailsFromNote(lldb_private::DataExtractor &data,
1163                                            lldb_private::ArchSpec &arch_spec,
1164                                            lldb_private::UUID &uuid) {
1165   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_MODULES));
1166   Status error;
1167 
1168   lldb::offset_t offset = 0;
1169 
1170   while (true) {
1171     // Parse the note header.  If this fails, bail out.
1172     const lldb::offset_t note_offset = offset;
1173     ELFNote note = ELFNote();
1174     if (!note.Parse(data, &offset)) {
1175       // We're done.
1176       return error;
1177     }
1178 
1179     if (log)
1180       log->Printf("ObjectFileELF::%s parsing note name='%s', type=%" PRIu32,
1181                   __FUNCTION__, note.n_name.c_str(), note.n_type);
1182 
1183     // Process FreeBSD ELF notes.
1184     if ((note.n_name == LLDB_NT_OWNER_FREEBSD) &&
1185         (note.n_type == LLDB_NT_FREEBSD_ABI_TAG) &&
1186         (note.n_descsz == LLDB_NT_FREEBSD_ABI_SIZE)) {
1187       // Pull out the min version info.
1188       uint32_t version_info;
1189       if (data.GetU32(&offset, &version_info, 1) == nullptr) {
1190         error.SetErrorString("failed to read FreeBSD ABI note payload");
1191         return error;
1192       }
1193 
1194       // Convert the version info into a major/minor number.
1195       const uint32_t version_major = version_info / 100000;
1196       const uint32_t version_minor = (version_info / 1000) % 100;
1197 
1198       char os_name[32];
1199       snprintf(os_name, sizeof(os_name), "freebsd%" PRIu32 ".%" PRIu32,
1200                version_major, version_minor);
1201 
1202       // Set the elf OS version to FreeBSD.  Also clear the vendor.
1203       arch_spec.GetTriple().setOSName(os_name);
1204       arch_spec.GetTriple().setVendor(llvm::Triple::VendorType::UnknownVendor);
1205 
1206       if (log)
1207         log->Printf("ObjectFileELF::%s detected FreeBSD %" PRIu32 ".%" PRIu32
1208                     ".%" PRIu32,
1209                     __FUNCTION__, version_major, version_minor,
1210                     static_cast<uint32_t>(version_info % 1000));
1211     }
1212     // Process GNU ELF notes.
1213     else if (note.n_name == LLDB_NT_OWNER_GNU) {
1214       switch (note.n_type) {
1215       case LLDB_NT_GNU_ABI_TAG:
1216         if (note.n_descsz == LLDB_NT_GNU_ABI_SIZE) {
1217           // Pull out the min OS version supporting the ABI.
1218           uint32_t version_info[4];
1219           if (data.GetU32(&offset, &version_info[0], note.n_descsz / 4) ==
1220               nullptr) {
1221             error.SetErrorString("failed to read GNU ABI note payload");
1222             return error;
1223           }
1224 
1225           // Set the OS per the OS field.
1226           switch (version_info[0]) {
1227           case LLDB_NT_GNU_ABI_OS_LINUX:
1228             arch_spec.GetTriple().setOS(llvm::Triple::OSType::Linux);
1229             arch_spec.GetTriple().setVendor(
1230                 llvm::Triple::VendorType::UnknownVendor);
1231             if (log)
1232               log->Printf(
1233                   "ObjectFileELF::%s detected Linux, min version %" PRIu32
1234                   ".%" PRIu32 ".%" PRIu32,
1235                   __FUNCTION__, version_info[1], version_info[2],
1236                   version_info[3]);
1237             // FIXME we have the minimal version number, we could be propagating
1238             // that.  version_info[1] = OS Major, version_info[2] = OS Minor,
1239             // version_info[3] = Revision.
1240             break;
1241           case LLDB_NT_GNU_ABI_OS_HURD:
1242             arch_spec.GetTriple().setOS(llvm::Triple::OSType::UnknownOS);
1243             arch_spec.GetTriple().setVendor(
1244                 llvm::Triple::VendorType::UnknownVendor);
1245             if (log)
1246               log->Printf("ObjectFileELF::%s detected Hurd (unsupported), min "
1247                           "version %" PRIu32 ".%" PRIu32 ".%" PRIu32,
1248                           __FUNCTION__, version_info[1], version_info[2],
1249                           version_info[3]);
1250             break;
1251           case LLDB_NT_GNU_ABI_OS_SOLARIS:
1252             arch_spec.GetTriple().setOS(llvm::Triple::OSType::Solaris);
1253             arch_spec.GetTriple().setVendor(
1254                 llvm::Triple::VendorType::UnknownVendor);
1255             if (log)
1256               log->Printf(
1257                   "ObjectFileELF::%s detected Solaris, min version %" PRIu32
1258                   ".%" PRIu32 ".%" PRIu32,
1259                   __FUNCTION__, version_info[1], version_info[2],
1260                   version_info[3]);
1261             break;
1262           default:
1263             if (log)
1264               log->Printf(
1265                   "ObjectFileELF::%s unrecognized OS in note, id %" PRIu32
1266                   ", min version %" PRIu32 ".%" PRIu32 ".%" PRIu32,
1267                   __FUNCTION__, version_info[0], version_info[1],
1268                   version_info[2], version_info[3]);
1269             break;
1270           }
1271         }
1272         break;
1273 
1274       case LLDB_NT_GNU_BUILD_ID_TAG:
1275         // Only bother processing this if we don't already have the uuid set.
1276         if (!uuid.IsValid()) {
1277           // 16 bytes is UUID|MD5, 20 bytes is SHA1. Other linkers may produce a
1278           // build-id of a different length. Accept it as long as it's at least
1279           // 4 bytes as it will be better than our own crc32.
1280           if (note.n_descsz >= 4) {
1281             if (const uint8_t *buf = data.PeekData(offset, note.n_descsz)) {
1282               // Save the build id as the UUID for the module.
1283               uuid = UUID::fromData(buf, note.n_descsz);
1284             } else {
1285               error.SetErrorString("failed to read GNU_BUILD_ID note payload");
1286               return error;
1287             }
1288           }
1289         }
1290         break;
1291       }
1292       if (arch_spec.IsMIPS() &&
1293           arch_spec.GetTriple().getOS() == llvm::Triple::OSType::UnknownOS)
1294         // The note.n_name == LLDB_NT_OWNER_GNU is valid for Linux platform
1295         arch_spec.GetTriple().setOS(llvm::Triple::OSType::Linux);
1296     }
1297     // Process NetBSD ELF notes.
1298     else if ((note.n_name == LLDB_NT_OWNER_NETBSD) &&
1299              (note.n_type == LLDB_NT_NETBSD_ABI_TAG) &&
1300              (note.n_descsz == LLDB_NT_NETBSD_ABI_SIZE)) {
1301       // Pull out the min version info.
1302       uint32_t version_info;
1303       if (data.GetU32(&offset, &version_info, 1) == nullptr) {
1304         error.SetErrorString("failed to read NetBSD ABI note payload");
1305         return error;
1306       }
1307 
1308       // Set the elf OS version to NetBSD.  Also clear the vendor.
1309       arch_spec.GetTriple().setOS(llvm::Triple::OSType::NetBSD);
1310       arch_spec.GetTriple().setVendor(llvm::Triple::VendorType::UnknownVendor);
1311 
1312       if (log)
1313         log->Printf(
1314             "ObjectFileELF::%s detected NetBSD, min version constant %" PRIu32,
1315             __FUNCTION__, version_info);
1316     }
1317     // Process OpenBSD ELF notes.
1318     else if (note.n_name == LLDB_NT_OWNER_OPENBSD) {
1319       // Set the elf OS version to OpenBSD.  Also clear the vendor.
1320       arch_spec.GetTriple().setOS(llvm::Triple::OSType::OpenBSD);
1321       arch_spec.GetTriple().setVendor(llvm::Triple::VendorType::UnknownVendor);
1322     }
1323     // Process CSR kalimba notes
1324     else if ((note.n_type == LLDB_NT_GNU_ABI_TAG) &&
1325              (note.n_name == LLDB_NT_OWNER_CSR)) {
1326       arch_spec.GetTriple().setOS(llvm::Triple::OSType::UnknownOS);
1327       arch_spec.GetTriple().setVendor(llvm::Triple::VendorType::CSR);
1328 
1329       // TODO At some point the description string could be processed.
1330       // It could provide a steer towards the kalimba variant which this ELF
1331       // targets.
1332       if (note.n_descsz) {
1333         const char *cstr =
1334             data.GetCStr(&offset, llvm::alignTo(note.n_descsz, 4));
1335         (void)cstr;
1336       }
1337     } else if (note.n_name == LLDB_NT_OWNER_ANDROID) {
1338       arch_spec.GetTriple().setOS(llvm::Triple::OSType::Linux);
1339       arch_spec.GetTriple().setEnvironment(
1340           llvm::Triple::EnvironmentType::Android);
1341     } else if (note.n_name == LLDB_NT_OWNER_LINUX) {
1342       // This is sometimes found in core files and usually contains extended
1343       // register info
1344       arch_spec.GetTriple().setOS(llvm::Triple::OSType::Linux);
1345     } else if (note.n_name == LLDB_NT_OWNER_CORE) {
1346       // Parse the NT_FILE to look for stuff in paths to shared libraries As
1347       // the contents look like this in a 64 bit ELF core file: count     =
1348       // 0x000000000000000a (10) page_size = 0x0000000000001000 (4096) Index
1349       // start              end                file_ofs           path =====
1350       // ------------------ ------------------ ------------------
1351       // ------------------------------------- [  0] 0x0000000000400000
1352       // 0x0000000000401000 0x0000000000000000 /tmp/a.out [  1]
1353       // 0x0000000000600000 0x0000000000601000 0x0000000000000000 /tmp/a.out [
1354       // 2] 0x0000000000601000 0x0000000000602000 0x0000000000000001 /tmp/a.out
1355       // [  3] 0x00007fa79c9ed000 0x00007fa79cba8000 0x0000000000000000
1356       // /lib/x86_64-linux-gnu/libc-2.19.so [  4] 0x00007fa79cba8000
1357       // 0x00007fa79cda7000 0x00000000000001bb /lib/x86_64-linux-
1358       // gnu/libc-2.19.so [  5] 0x00007fa79cda7000 0x00007fa79cdab000
1359       // 0x00000000000001ba /lib/x86_64-linux-gnu/libc-2.19.so [  6]
1360       // 0x00007fa79cdab000 0x00007fa79cdad000 0x00000000000001be /lib/x86_64
1361       // -linux-gnu/libc-2.19.so [  7] 0x00007fa79cdb2000 0x00007fa79cdd5000
1362       // 0x0000000000000000 /lib/x86_64-linux-gnu/ld-2.19.so [  8]
1363       // 0x00007fa79cfd4000 0x00007fa79cfd5000 0x0000000000000022 /lib/x86_64
1364       // -linux-gnu/ld-2.19.so [  9] 0x00007fa79cfd5000 0x00007fa79cfd6000
1365       // 0x0000000000000023 /lib/x86_64-linux-gnu/ld-2.19.so In the 32 bit ELFs
1366       // the count, page_size, start, end, file_ofs are uint32_t For reference:
1367       // see readelf source code (in binutils).
1368       if (note.n_type == NT_FILE) {
1369         uint64_t count = data.GetAddress(&offset);
1370         const char *cstr;
1371         data.GetAddress(&offset); // Skip page size
1372         offset += count * 3 *
1373                   data.GetAddressByteSize(); // Skip all start/end/file_ofs
1374         for (size_t i = 0; i < count; ++i) {
1375           cstr = data.GetCStr(&offset);
1376           if (cstr == nullptr) {
1377             error.SetErrorStringWithFormat("ObjectFileELF::%s trying to read "
1378                                            "at an offset after the end "
1379                                            "(GetCStr returned nullptr)",
1380                                            __FUNCTION__);
1381             return error;
1382           }
1383           llvm::StringRef path(cstr);
1384           if (path.contains("/lib/x86_64-linux-gnu") || path.contains("/lib/i386-linux-gnu")) {
1385             arch_spec.GetTriple().setOS(llvm::Triple::OSType::Linux);
1386             break;
1387           }
1388         }
1389         if (arch_spec.IsMIPS() &&
1390             arch_spec.GetTriple().getOS() == llvm::Triple::OSType::UnknownOS)
1391           // In case of MIPSR6, the LLDB_NT_OWNER_GNU note is missing for some
1392           // cases (e.g. compile with -nostdlib) Hence set OS to Linux
1393           arch_spec.GetTriple().setOS(llvm::Triple::OSType::Linux);
1394       }
1395     }
1396 
1397     // Calculate the offset of the next note just in case "offset" has been
1398     // used to poke at the contents of the note data
1399     offset = note_offset + note.GetByteSize();
1400   }
1401 
1402   return error;
1403 }
1404 
1405 void ObjectFileELF::ParseARMAttributes(DataExtractor &data, uint64_t length,
1406                                        ArchSpec &arch_spec) {
1407   lldb::offset_t Offset = 0;
1408 
1409   uint8_t FormatVersion = data.GetU8(&Offset);
1410   if (FormatVersion != llvm::ARMBuildAttrs::Format_Version)
1411     return;
1412 
1413   Offset = Offset + sizeof(uint32_t); // Section Length
1414   llvm::StringRef VendorName = data.GetCStr(&Offset);
1415 
1416   if (VendorName != "aeabi")
1417     return;
1418 
1419   if (arch_spec.GetTriple().getEnvironment() ==
1420       llvm::Triple::UnknownEnvironment)
1421     arch_spec.GetTriple().setEnvironment(llvm::Triple::EABI);
1422 
1423   while (Offset < length) {
1424     uint8_t Tag = data.GetU8(&Offset);
1425     uint32_t Size = data.GetU32(&Offset);
1426 
1427     if (Tag != llvm::ARMBuildAttrs::File || Size == 0)
1428       continue;
1429 
1430     while (Offset < length) {
1431       uint64_t Tag = data.GetULEB128(&Offset);
1432       switch (Tag) {
1433       default:
1434         if (Tag < 32)
1435           data.GetULEB128(&Offset);
1436         else if (Tag % 2 == 0)
1437           data.GetULEB128(&Offset);
1438         else
1439           data.GetCStr(&Offset);
1440 
1441         break;
1442 
1443       case llvm::ARMBuildAttrs::CPU_raw_name:
1444       case llvm::ARMBuildAttrs::CPU_name:
1445         data.GetCStr(&Offset);
1446 
1447         break;
1448 
1449       case llvm::ARMBuildAttrs::ABI_VFP_args: {
1450         uint64_t VFPArgs = data.GetULEB128(&Offset);
1451 
1452         if (VFPArgs == llvm::ARMBuildAttrs::BaseAAPCS) {
1453           if (arch_spec.GetTriple().getEnvironment() ==
1454                   llvm::Triple::UnknownEnvironment ||
1455               arch_spec.GetTriple().getEnvironment() == llvm::Triple::EABIHF)
1456             arch_spec.GetTriple().setEnvironment(llvm::Triple::EABI);
1457 
1458           arch_spec.SetFlags(ArchSpec::eARM_abi_soft_float);
1459         } else if (VFPArgs == llvm::ARMBuildAttrs::HardFPAAPCS) {
1460           if (arch_spec.GetTriple().getEnvironment() ==
1461                   llvm::Triple::UnknownEnvironment ||
1462               arch_spec.GetTriple().getEnvironment() == llvm::Triple::EABI)
1463             arch_spec.GetTriple().setEnvironment(llvm::Triple::EABIHF);
1464 
1465           arch_spec.SetFlags(ArchSpec::eARM_abi_hard_float);
1466         }
1467 
1468         break;
1469       }
1470       }
1471     }
1472   }
1473 }
1474 
1475 //----------------------------------------------------------------------
1476 // GetSectionHeaderInfo
1477 //----------------------------------------------------------------------
1478 size_t ObjectFileELF::GetSectionHeaderInfo(SectionHeaderColl &section_headers,
1479                                            DataExtractor &object_data,
1480                                            const elf::ELFHeader &header,
1481                                            lldb_private::UUID &uuid,
1482                                            std::string &gnu_debuglink_file,
1483                                            uint32_t &gnu_debuglink_crc,
1484                                            ArchSpec &arch_spec) {
1485   // Don't reparse the section headers if we already did that.
1486   if (!section_headers.empty())
1487     return section_headers.size();
1488 
1489   // Only initialize the arch_spec to okay defaults if they're not already set.
1490   // We'll refine this with note data as we parse the notes.
1491   if (arch_spec.GetTriple().getOS() == llvm::Triple::OSType::UnknownOS) {
1492     llvm::Triple::OSType ostype;
1493     llvm::Triple::OSType spec_ostype;
1494     const uint32_t sub_type = subTypeFromElfHeader(header);
1495     arch_spec.SetArchitecture(eArchTypeELF, header.e_machine, sub_type,
1496                               header.e_ident[EI_OSABI]);
1497 
1498     // Validate if it is ok to remove GetOsFromOSABI. Note, that now the OS is
1499     // determined based on EI_OSABI flag and the info extracted from ELF notes
1500     // (see RefineModuleDetailsFromNote). However in some cases that still
1501     // might be not enough: for example a shared library might not have any
1502     // notes at all and have EI_OSABI flag set to System V, as result the OS
1503     // will be set to UnknownOS.
1504     GetOsFromOSABI(header.e_ident[EI_OSABI], ostype);
1505     spec_ostype = arch_spec.GetTriple().getOS();
1506     assert(spec_ostype == ostype);
1507     UNUSED_IF_ASSERT_DISABLED(spec_ostype);
1508   }
1509 
1510   if (arch_spec.GetMachine() == llvm::Triple::mips ||
1511       arch_spec.GetMachine() == llvm::Triple::mipsel ||
1512       arch_spec.GetMachine() == llvm::Triple::mips64 ||
1513       arch_spec.GetMachine() == llvm::Triple::mips64el) {
1514     switch (header.e_flags & llvm::ELF::EF_MIPS_ARCH_ASE) {
1515     case llvm::ELF::EF_MIPS_MICROMIPS:
1516       arch_spec.SetFlags(ArchSpec::eMIPSAse_micromips);
1517       break;
1518     case llvm::ELF::EF_MIPS_ARCH_ASE_M16:
1519       arch_spec.SetFlags(ArchSpec::eMIPSAse_mips16);
1520       break;
1521     case llvm::ELF::EF_MIPS_ARCH_ASE_MDMX:
1522       arch_spec.SetFlags(ArchSpec::eMIPSAse_mdmx);
1523       break;
1524     default:
1525       break;
1526     }
1527   }
1528 
1529   if (arch_spec.GetMachine() == llvm::Triple::arm ||
1530       arch_spec.GetMachine() == llvm::Triple::thumb) {
1531     if (header.e_flags & llvm::ELF::EF_ARM_SOFT_FLOAT)
1532       arch_spec.SetFlags(ArchSpec::eARM_abi_soft_float);
1533     else if (header.e_flags & llvm::ELF::EF_ARM_VFP_FLOAT)
1534       arch_spec.SetFlags(ArchSpec::eARM_abi_hard_float);
1535   }
1536 
1537   // If there are no section headers we are done.
1538   if (header.e_shnum == 0)
1539     return 0;
1540 
1541   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_MODULES));
1542 
1543   section_headers.resize(header.e_shnum);
1544   if (section_headers.size() != header.e_shnum)
1545     return 0;
1546 
1547   const size_t sh_size = header.e_shnum * header.e_shentsize;
1548   const elf_off sh_offset = header.e_shoff;
1549   DataExtractor sh_data;
1550   if (sh_data.SetData(object_data, sh_offset, sh_size) != sh_size)
1551     return 0;
1552 
1553   uint32_t idx;
1554   lldb::offset_t offset;
1555   for (idx = 0, offset = 0; idx < header.e_shnum; ++idx) {
1556     if (section_headers[idx].Parse(sh_data, &offset) == false)
1557       break;
1558   }
1559   if (idx < section_headers.size())
1560     section_headers.resize(idx);
1561 
1562   const unsigned strtab_idx = header.e_shstrndx;
1563   if (strtab_idx && strtab_idx < section_headers.size()) {
1564     const ELFSectionHeaderInfo &sheader = section_headers[strtab_idx];
1565     const size_t byte_size = sheader.sh_size;
1566     const Elf64_Off offset = sheader.sh_offset;
1567     lldb_private::DataExtractor shstr_data;
1568 
1569     if (shstr_data.SetData(object_data, offset, byte_size) == byte_size) {
1570       for (SectionHeaderCollIter I = section_headers.begin();
1571            I != section_headers.end(); ++I) {
1572         static ConstString g_sect_name_gnu_debuglink(".gnu_debuglink");
1573         const ELFSectionHeaderInfo &sheader = *I;
1574         const uint64_t section_size =
1575             sheader.sh_type == SHT_NOBITS ? 0 : sheader.sh_size;
1576         ConstString name(shstr_data.PeekCStr(I->sh_name));
1577 
1578         I->section_name = name;
1579 
1580         if (arch_spec.IsMIPS()) {
1581           uint32_t arch_flags = arch_spec.GetFlags();
1582           DataExtractor data;
1583           if (sheader.sh_type == SHT_MIPS_ABIFLAGS) {
1584 
1585             if (section_size && (data.SetData(object_data, sheader.sh_offset,
1586                                               section_size) == section_size)) {
1587               // MIPS ASE Mask is at offset 12 in MIPS.abiflags section
1588               lldb::offset_t offset = 12; // MIPS ABI Flags Version: 0
1589               arch_flags |= data.GetU32(&offset);
1590 
1591               // The floating point ABI is at offset 7
1592               offset = 7;
1593               switch (data.GetU8(&offset)) {
1594               case llvm::Mips::Val_GNU_MIPS_ABI_FP_ANY:
1595                 arch_flags |= lldb_private::ArchSpec::eMIPS_ABI_FP_ANY;
1596                 break;
1597               case llvm::Mips::Val_GNU_MIPS_ABI_FP_DOUBLE:
1598                 arch_flags |= lldb_private::ArchSpec::eMIPS_ABI_FP_DOUBLE;
1599                 break;
1600               case llvm::Mips::Val_GNU_MIPS_ABI_FP_SINGLE:
1601                 arch_flags |= lldb_private::ArchSpec::eMIPS_ABI_FP_SINGLE;
1602                 break;
1603               case llvm::Mips::Val_GNU_MIPS_ABI_FP_SOFT:
1604                 arch_flags |= lldb_private::ArchSpec::eMIPS_ABI_FP_SOFT;
1605                 break;
1606               case llvm::Mips::Val_GNU_MIPS_ABI_FP_OLD_64:
1607                 arch_flags |= lldb_private::ArchSpec::eMIPS_ABI_FP_OLD_64;
1608                 break;
1609               case llvm::Mips::Val_GNU_MIPS_ABI_FP_XX:
1610                 arch_flags |= lldb_private::ArchSpec::eMIPS_ABI_FP_XX;
1611                 break;
1612               case llvm::Mips::Val_GNU_MIPS_ABI_FP_64:
1613                 arch_flags |= lldb_private::ArchSpec::eMIPS_ABI_FP_64;
1614                 break;
1615               case llvm::Mips::Val_GNU_MIPS_ABI_FP_64A:
1616                 arch_flags |= lldb_private::ArchSpec::eMIPS_ABI_FP_64A;
1617                 break;
1618               }
1619             }
1620           }
1621           // Settings appropriate ArchSpec ABI Flags
1622           switch (header.e_flags & llvm::ELF::EF_MIPS_ABI) {
1623           case llvm::ELF::EF_MIPS_ABI_O32:
1624             arch_flags |= lldb_private::ArchSpec::eMIPSABI_O32;
1625             break;
1626           case EF_MIPS_ABI_O64:
1627             arch_flags |= lldb_private::ArchSpec::eMIPSABI_O64;
1628             break;
1629           case EF_MIPS_ABI_EABI32:
1630             arch_flags |= lldb_private::ArchSpec::eMIPSABI_EABI32;
1631             break;
1632           case EF_MIPS_ABI_EABI64:
1633             arch_flags |= lldb_private::ArchSpec::eMIPSABI_EABI64;
1634             break;
1635           default:
1636             // ABI Mask doesn't cover N32 and N64 ABI.
1637             if (header.e_ident[EI_CLASS] == llvm::ELF::ELFCLASS64)
1638               arch_flags |= lldb_private::ArchSpec::eMIPSABI_N64;
1639             else if (header.e_flags & llvm::ELF::EF_MIPS_ABI2)
1640               arch_flags |= lldb_private::ArchSpec::eMIPSABI_N32;
1641             break;
1642           }
1643           arch_spec.SetFlags(arch_flags);
1644         }
1645 
1646         if (arch_spec.GetMachine() == llvm::Triple::arm ||
1647             arch_spec.GetMachine() == llvm::Triple::thumb) {
1648           DataExtractor data;
1649 
1650           if (sheader.sh_type == SHT_ARM_ATTRIBUTES && section_size != 0 &&
1651               data.SetData(object_data, sheader.sh_offset, section_size) == section_size)
1652             ParseARMAttributes(data, section_size, arch_spec);
1653         }
1654 
1655         if (name == g_sect_name_gnu_debuglink) {
1656           DataExtractor data;
1657           if (section_size && (data.SetData(object_data, sheader.sh_offset,
1658                                             section_size) == section_size)) {
1659             lldb::offset_t gnu_debuglink_offset = 0;
1660             gnu_debuglink_file = data.GetCStr(&gnu_debuglink_offset);
1661             gnu_debuglink_offset = llvm::alignTo(gnu_debuglink_offset, 4);
1662             data.GetU32(&gnu_debuglink_offset, &gnu_debuglink_crc, 1);
1663           }
1664         }
1665 
1666         // Process ELF note section entries.
1667         bool is_note_header = (sheader.sh_type == SHT_NOTE);
1668 
1669         // The section header ".note.android.ident" is stored as a
1670         // PROGBITS type header but it is actually a note header.
1671         static ConstString g_sect_name_android_ident(".note.android.ident");
1672         if (!is_note_header && name == g_sect_name_android_ident)
1673           is_note_header = true;
1674 
1675         if (is_note_header) {
1676           // Allow notes to refine module info.
1677           DataExtractor data;
1678           if (section_size && (data.SetData(object_data, sheader.sh_offset,
1679                                             section_size) == section_size)) {
1680             Status error = RefineModuleDetailsFromNote(data, arch_spec, uuid);
1681             if (error.Fail()) {
1682               if (log)
1683                 log->Printf("ObjectFileELF::%s ELF note processing failed: %s",
1684                             __FUNCTION__, error.AsCString());
1685             }
1686           }
1687         }
1688       }
1689 
1690       // Make any unknown triple components to be unspecified unknowns.
1691       if (arch_spec.GetTriple().getVendor() == llvm::Triple::UnknownVendor)
1692         arch_spec.GetTriple().setVendorName(llvm::StringRef());
1693       if (arch_spec.GetTriple().getOS() == llvm::Triple::UnknownOS)
1694         arch_spec.GetTriple().setOSName(llvm::StringRef());
1695 
1696       return section_headers.size();
1697     }
1698   }
1699 
1700   section_headers.clear();
1701   return 0;
1702 }
1703 
1704 size_t ObjectFileELF::GetProgramHeaderCount() { return ParseProgramHeaders(); }
1705 
1706 const elf::ELFProgramHeader *
1707 ObjectFileELF::GetProgramHeaderByIndex(lldb::user_id_t id) {
1708   if (!id || !ParseProgramHeaders())
1709     return NULL;
1710 
1711   if (--id < m_program_headers.size())
1712     return &m_program_headers[id];
1713 
1714   return NULL;
1715 }
1716 
1717 DataExtractor ObjectFileELF::GetSegmentDataByIndex(lldb::user_id_t id) {
1718   const elf::ELFProgramHeader *segment_header = GetProgramHeaderByIndex(id);
1719   if (segment_header == NULL)
1720     return DataExtractor();
1721   return DataExtractor(m_data, segment_header->p_offset,
1722                        segment_header->p_filesz);
1723 }
1724 
1725 llvm::StringRef
1726 ObjectFileELF::StripLinkerSymbolAnnotations(llvm::StringRef symbol_name) const {
1727   size_t pos = symbol_name.find('@');
1728   return symbol_name.substr(0, pos);
1729 }
1730 
1731 //----------------------------------------------------------------------
1732 // ParseSectionHeaders
1733 //----------------------------------------------------------------------
1734 size_t ObjectFileELF::ParseSectionHeaders() {
1735   return GetSectionHeaderInfo(m_section_headers, m_data, m_header, m_uuid,
1736                               m_gnu_debuglink_file, m_gnu_debuglink_crc,
1737                               m_arch_spec);
1738 }
1739 
1740 const ObjectFileELF::ELFSectionHeaderInfo *
1741 ObjectFileELF::GetSectionHeaderByIndex(lldb::user_id_t id) {
1742   if (!id || !ParseSectionHeaders())
1743     return NULL;
1744 
1745   if (--id < m_section_headers.size())
1746     return &m_section_headers[id];
1747 
1748   return NULL;
1749 }
1750 
1751 lldb::user_id_t ObjectFileELF::GetSectionIndexByName(const char *name) {
1752   if (!name || !name[0] || !ParseSectionHeaders())
1753     return 0;
1754   for (size_t i = 1; i < m_section_headers.size(); ++i)
1755     if (m_section_headers[i].section_name == ConstString(name))
1756       return i;
1757   return 0;
1758 }
1759 
1760 void ObjectFileELF::CreateSections(SectionList &unified_section_list) {
1761   if (!m_sections_ap.get() && ParseSectionHeaders()) {
1762     m_sections_ap.reset(new SectionList());
1763 
1764     // Object files frequently have 0 for every section address, meaning we
1765     // need to compute synthetic addresses in order for "file addresses" from
1766     // different sections to not overlap
1767     bool synthaddrs = (CalculateType() == ObjectFile::Type::eTypeObjectFile);
1768     uint64_t nextaddr = 0;
1769 
1770     for (SectionHeaderCollIter I = m_section_headers.begin();
1771          I != m_section_headers.end(); ++I) {
1772       const ELFSectionHeaderInfo &header = *I;
1773 
1774       ConstString &name = I->section_name;
1775       const uint64_t file_size =
1776           header.sh_type == SHT_NOBITS ? 0 : header.sh_size;
1777       const uint64_t vm_size = header.sh_flags & SHF_ALLOC ? header.sh_size : 0;
1778 
1779       static ConstString g_sect_name_text(".text");
1780       static ConstString g_sect_name_data(".data");
1781       static ConstString g_sect_name_bss(".bss");
1782       static ConstString g_sect_name_tdata(".tdata");
1783       static ConstString g_sect_name_tbss(".tbss");
1784       static ConstString g_sect_name_dwarf_debug_abbrev(".debug_abbrev");
1785       static ConstString g_sect_name_dwarf_debug_addr(".debug_addr");
1786       static ConstString g_sect_name_dwarf_debug_aranges(".debug_aranges");
1787       static ConstString g_sect_name_dwarf_debug_cu_index(".debug_cu_index");
1788       static ConstString g_sect_name_dwarf_debug_frame(".debug_frame");
1789       static ConstString g_sect_name_dwarf_debug_info(".debug_info");
1790       static ConstString g_sect_name_dwarf_debug_line(".debug_line");
1791       static ConstString g_sect_name_dwarf_debug_line_str(".debug_line_str");
1792       static ConstString g_sect_name_dwarf_debug_loc(".debug_loc");
1793       static ConstString g_sect_name_dwarf_debug_macinfo(".debug_macinfo");
1794       static ConstString g_sect_name_dwarf_debug_macro(".debug_macro");
1795       static ConstString g_sect_name_dwarf_debug_names(".debug_names");
1796       static ConstString g_sect_name_dwarf_debug_pubnames(".debug_pubnames");
1797       static ConstString g_sect_name_dwarf_debug_pubtypes(".debug_pubtypes");
1798       static ConstString g_sect_name_dwarf_debug_ranges(".debug_ranges");
1799       static ConstString g_sect_name_dwarf_debug_str(".debug_str");
1800       static ConstString g_sect_name_dwarf_debug_str_offsets(
1801           ".debug_str_offsets");
1802       static ConstString g_sect_name_dwarf_debug_abbrev_dwo(
1803           ".debug_abbrev.dwo");
1804       static ConstString g_sect_name_dwarf_debug_info_dwo(".debug_info.dwo");
1805       static ConstString g_sect_name_dwarf_debug_line_dwo(".debug_line.dwo");
1806       static ConstString g_sect_name_dwarf_debug_line_str_dwo(".debug_line_str.dwo");
1807       static ConstString g_sect_name_dwarf_debug_macro_dwo(".debug_macro.dwo");
1808       static ConstString g_sect_name_dwarf_debug_loc_dwo(".debug_loc.dwo");
1809       static ConstString g_sect_name_dwarf_debug_str_dwo(".debug_str.dwo");
1810       static ConstString g_sect_name_dwarf_debug_str_offsets_dwo(
1811           ".debug_str_offsets.dwo");
1812       static ConstString g_sect_name_dwarf_debug_types(".debug_types");
1813       static ConstString g_sect_name_eh_frame(".eh_frame");
1814       static ConstString g_sect_name_arm_exidx(".ARM.exidx");
1815       static ConstString g_sect_name_arm_extab(".ARM.extab");
1816       static ConstString g_sect_name_go_symtab(".gosymtab");
1817       static ConstString g_sect_name_dwarf_gnu_debugaltlink(".gnu_debugaltlink");
1818 
1819       SectionType sect_type = eSectionTypeOther;
1820 
1821       bool is_thread_specific = false;
1822 
1823       if (name == g_sect_name_text)
1824         sect_type = eSectionTypeCode;
1825       else if (name == g_sect_name_data)
1826         sect_type = eSectionTypeData;
1827       else if (name == g_sect_name_bss)
1828         sect_type = eSectionTypeZeroFill;
1829       else if (name == g_sect_name_tdata) {
1830         sect_type = eSectionTypeData;
1831         is_thread_specific = true;
1832       } else if (name == g_sect_name_tbss) {
1833         sect_type = eSectionTypeZeroFill;
1834         is_thread_specific = true;
1835       }
1836       // .debug_abbrev – Abbreviations used in the .debug_info section
1837       // .debug_aranges – Lookup table for mapping addresses to compilation
1838       // units .debug_frame – Call frame information .debug_info – The core
1839       // DWARF information section .debug_line – Line number information
1840       // .debug_loc – Location lists used in DW_AT_location attributes
1841       // .debug_macinfo – Macro information .debug_pubnames – Lookup table
1842       // for mapping object and function names to compilation units
1843       // .debug_pubtypes – Lookup table for mapping type names to compilation
1844       // units .debug_ranges – Address ranges used in DW_AT_ranges attributes
1845       // .debug_str – String table used in .debug_info MISSING?
1846       // .gnu_debugdata - "mini debuginfo / MiniDebugInfo" section,
1847       // http://sourceware.org/gdb/onlinedocs/gdb/MiniDebugInfo.html MISSING?
1848       // .debug-index - http://src.chromium.org/viewvc/chrome/trunk/src/build
1849       // /gdb-add-index?pathrev=144644 MISSING? .debug_types - Type
1850       // descriptions from DWARF 4? See
1851       // http://gcc.gnu.org/wiki/DwarfSeparateTypeInfo
1852       else if (name == g_sect_name_dwarf_debug_abbrev)
1853         sect_type = eSectionTypeDWARFDebugAbbrev;
1854       else if (name == g_sect_name_dwarf_debug_addr)
1855         sect_type = eSectionTypeDWARFDebugAddr;
1856       else if (name == g_sect_name_dwarf_debug_aranges)
1857         sect_type = eSectionTypeDWARFDebugAranges;
1858       else if (name == g_sect_name_dwarf_debug_cu_index)
1859         sect_type = eSectionTypeDWARFDebugCuIndex;
1860       else if (name == g_sect_name_dwarf_debug_frame)
1861         sect_type = eSectionTypeDWARFDebugFrame;
1862       else if (name == g_sect_name_dwarf_debug_info)
1863         sect_type = eSectionTypeDWARFDebugInfo;
1864       else if (name == g_sect_name_dwarf_debug_line)
1865         sect_type = eSectionTypeDWARFDebugLine;
1866       else if (name == g_sect_name_dwarf_debug_line_str)
1867         sect_type = eSectionTypeDWARFDebugLineStr;
1868       else if (name == g_sect_name_dwarf_debug_loc)
1869         sect_type = eSectionTypeDWARFDebugLoc;
1870       else if (name == g_sect_name_dwarf_debug_macinfo)
1871         sect_type = eSectionTypeDWARFDebugMacInfo;
1872       else if (name == g_sect_name_dwarf_debug_macro)
1873         sect_type = eSectionTypeDWARFDebugMacro;
1874       else if (name == g_sect_name_dwarf_debug_names)
1875         sect_type = eSectionTypeDWARFDebugNames;
1876       else if (name == g_sect_name_dwarf_debug_pubnames)
1877         sect_type = eSectionTypeDWARFDebugPubNames;
1878       else if (name == g_sect_name_dwarf_debug_pubtypes)
1879         sect_type = eSectionTypeDWARFDebugPubTypes;
1880       else if (name == g_sect_name_dwarf_debug_ranges)
1881         sect_type = eSectionTypeDWARFDebugRanges;
1882       else if (name == g_sect_name_dwarf_debug_str)
1883         sect_type = eSectionTypeDWARFDebugStr;
1884       else if (name == g_sect_name_dwarf_debug_types)
1885         sect_type = eSectionTypeDWARFDebugTypes;
1886       else if (name == g_sect_name_dwarf_debug_str_offsets)
1887         sect_type = eSectionTypeDWARFDebugStrOffsets;
1888       else if (name == g_sect_name_dwarf_debug_abbrev_dwo)
1889         sect_type = eSectionTypeDWARFDebugAbbrev;
1890       else if (name == g_sect_name_dwarf_debug_info_dwo)
1891         sect_type = eSectionTypeDWARFDebugInfo;
1892       else if (name == g_sect_name_dwarf_debug_line_dwo)
1893         sect_type = eSectionTypeDWARFDebugLine;
1894       else if (name == g_sect_name_dwarf_debug_line_str_dwo)
1895         sect_type = eSectionTypeDWARFDebugLineStr;
1896       else if (name == g_sect_name_dwarf_debug_macro_dwo)
1897         sect_type = eSectionTypeDWARFDebugMacro;
1898       else if (name == g_sect_name_dwarf_debug_loc_dwo)
1899         sect_type = eSectionTypeDWARFDebugLoc;
1900       else if (name == g_sect_name_dwarf_debug_str_dwo)
1901         sect_type = eSectionTypeDWARFDebugStr;
1902       else if (name == g_sect_name_dwarf_debug_str_offsets_dwo)
1903         sect_type = eSectionTypeDWARFDebugStrOffsets;
1904       else if (name == g_sect_name_eh_frame)
1905         sect_type = eSectionTypeEHFrame;
1906       else if (name == g_sect_name_arm_exidx)
1907         sect_type = eSectionTypeARMexidx;
1908       else if (name == g_sect_name_arm_extab)
1909         sect_type = eSectionTypeARMextab;
1910       else if (name == g_sect_name_go_symtab)
1911         sect_type = eSectionTypeGoSymtab;
1912       else if (name == g_sect_name_dwarf_gnu_debugaltlink)
1913         sect_type = eSectionTypeDWARFGNUDebugAltLink;
1914 
1915       const uint32_t permissions =
1916           ((header.sh_flags & SHF_ALLOC) ? ePermissionsReadable : 0u) |
1917           ((header.sh_flags & SHF_WRITE) ? ePermissionsWritable : 0u) |
1918           ((header.sh_flags & SHF_EXECINSTR) ? ePermissionsExecutable : 0u);
1919       switch (header.sh_type) {
1920       case SHT_SYMTAB:
1921         assert(sect_type == eSectionTypeOther);
1922         sect_type = eSectionTypeELFSymbolTable;
1923         break;
1924       case SHT_DYNSYM:
1925         assert(sect_type == eSectionTypeOther);
1926         sect_type = eSectionTypeELFDynamicSymbols;
1927         break;
1928       case SHT_RELA:
1929       case SHT_REL:
1930         assert(sect_type == eSectionTypeOther);
1931         sect_type = eSectionTypeELFRelocationEntries;
1932         break;
1933       case SHT_DYNAMIC:
1934         assert(sect_type == eSectionTypeOther);
1935         sect_type = eSectionTypeELFDynamicLinkInfo;
1936         break;
1937       }
1938 
1939       if (eSectionTypeOther == sect_type) {
1940         // the kalimba toolchain assumes that ELF section names are free-form.
1941         // It does support linkscripts which (can) give rise to various
1942         // arbitrarily named sections being "Code" or "Data".
1943         sect_type = kalimbaSectionType(m_header, header);
1944       }
1945 
1946       // In common case ELF code section can have arbitrary name (for example,
1947       // we can specify it using section attribute for particular function) so
1948       // assume that section is a code section if it has SHF_EXECINSTR flag set
1949       // and has SHT_PROGBITS type.
1950       if (eSectionTypeOther == sect_type &&
1951           llvm::ELF::SHT_PROGBITS == header.sh_type &&
1952           (header.sh_flags & SHF_EXECINSTR)) {
1953         sect_type = eSectionTypeCode;
1954       }
1955 
1956       const uint32_t target_bytes_size =
1957           (eSectionTypeData == sect_type || eSectionTypeZeroFill == sect_type)
1958               ? m_arch_spec.GetDataByteSize()
1959               : eSectionTypeCode == sect_type ? m_arch_spec.GetCodeByteSize()
1960                                               : 1;
1961       elf::elf_xword log2align =
1962           (header.sh_addralign == 0) ? 0 : llvm::Log2_64(header.sh_addralign);
1963 
1964       uint64_t addr = header.sh_addr;
1965 
1966       if ((header.sh_flags & SHF_ALLOC) && synthaddrs) {
1967           nextaddr =
1968               (nextaddr + header.sh_addralign - 1) & ~(header.sh_addralign - 1);
1969           addr = nextaddr;
1970           nextaddr += vm_size;
1971       }
1972 
1973       SectionSP section_sp(new Section(
1974           GetModule(), // Module to which this section belongs.
1975           this, // ObjectFile to which this section belongs and should read
1976                 // section data from.
1977           SectionIndex(I),     // Section ID.
1978           name,                // Section name.
1979           sect_type,           // Section type.
1980           addr,                // VM address.
1981           vm_size,             // VM size in bytes of this section.
1982           header.sh_offset,    // Offset of this section in the file.
1983           file_size,           // Size of the section as found in the file.
1984           log2align,           // Alignment of the section
1985           header.sh_flags,     // Flags for this section.
1986           target_bytes_size)); // Number of host bytes per target byte
1987 
1988       section_sp->SetPermissions(permissions);
1989       if (is_thread_specific)
1990         section_sp->SetIsThreadSpecific(is_thread_specific);
1991       m_sections_ap->AddSection(section_sp);
1992     }
1993   }
1994 
1995   // For eTypeDebugInfo files, the Symbol Vendor will take care of updating the
1996   // unified section list.
1997   if (GetType() != eTypeDebugInfo)
1998     unified_section_list = *m_sections_ap;
1999 }
2000 
2001 // Find the arm/aarch64 mapping symbol character in the given symbol name.
2002 // Mapping symbols have the form of "$<char>[.<any>]*". Additionally we
2003 // recognize cases when the mapping symbol prefixed by an arbitrary string
2004 // because if a symbol prefix added to each symbol in the object file with
2005 // objcopy then the mapping symbols are also prefixed.
2006 static char FindArmAarch64MappingSymbol(const char *symbol_name) {
2007   if (!symbol_name)
2008     return '\0';
2009 
2010   const char *dollar_pos = ::strchr(symbol_name, '$');
2011   if (!dollar_pos || dollar_pos[1] == '\0')
2012     return '\0';
2013 
2014   if (dollar_pos[2] == '\0' || dollar_pos[2] == '.')
2015     return dollar_pos[1];
2016   return '\0';
2017 }
2018 
2019 #define STO_MIPS_ISA (3 << 6)
2020 #define STO_MICROMIPS (2 << 6)
2021 #define IS_MICROMIPS(ST_OTHER) (((ST_OTHER)&STO_MIPS_ISA) == STO_MICROMIPS)
2022 
2023 // private
2024 unsigned ObjectFileELF::ParseSymbols(Symtab *symtab, user_id_t start_id,
2025                                      SectionList *section_list,
2026                                      const size_t num_symbols,
2027                                      const DataExtractor &symtab_data,
2028                                      const DataExtractor &strtab_data) {
2029   ELFSymbol symbol;
2030   lldb::offset_t offset = 0;
2031 
2032   static ConstString text_section_name(".text");
2033   static ConstString init_section_name(".init");
2034   static ConstString fini_section_name(".fini");
2035   static ConstString ctors_section_name(".ctors");
2036   static ConstString dtors_section_name(".dtors");
2037 
2038   static ConstString data_section_name(".data");
2039   static ConstString rodata_section_name(".rodata");
2040   static ConstString rodata1_section_name(".rodata1");
2041   static ConstString data2_section_name(".data1");
2042   static ConstString bss_section_name(".bss");
2043   static ConstString opd_section_name(".opd"); // For ppc64
2044 
2045   // On Android the oatdata and the oatexec symbols in the oat and odex files
2046   // covers the full .text section what causes issues with displaying unusable
2047   // symbol name to the user and very slow unwinding speed because the
2048   // instruction emulation based unwind plans try to emulate all instructions
2049   // in these symbols. Don't add these symbols to the symbol list as they have
2050   // no use for the debugger and they are causing a lot of trouble. Filtering
2051   // can't be restricted to Android because this special object file don't
2052   // contain the note section specifying the environment to Android but the
2053   // custom extension and file name makes it highly unlikely that this will
2054   // collide with anything else.
2055   ConstString file_extension = m_file.GetFileNameExtension();
2056   bool skip_oatdata_oatexec = file_extension == ConstString(".oat") ||
2057                               file_extension == ConstString(".odex");
2058 
2059   ArchSpec arch;
2060   GetArchitecture(arch);
2061   ModuleSP module_sp(GetModule());
2062   SectionList *module_section_list =
2063       module_sp ? module_sp->GetSectionList() : nullptr;
2064 
2065   // Local cache to avoid doing a FindSectionByName for each symbol. The "const
2066   // char*" key must came from a ConstString object so they can be compared by
2067   // pointer
2068   std::unordered_map<const char *, lldb::SectionSP> section_name_to_section;
2069 
2070   unsigned i;
2071   for (i = 0; i < num_symbols; ++i) {
2072     if (symbol.Parse(symtab_data, &offset) == false)
2073       break;
2074 
2075     const char *symbol_name = strtab_data.PeekCStr(symbol.st_name);
2076     if (!symbol_name)
2077       symbol_name = "";
2078 
2079     // No need to add non-section symbols that have no names
2080     if (symbol.getType() != STT_SECTION &&
2081         (symbol_name == nullptr || symbol_name[0] == '\0'))
2082       continue;
2083 
2084     // Skipping oatdata and oatexec sections if it is requested. See details
2085     // above the definition of skip_oatdata_oatexec for the reasons.
2086     if (skip_oatdata_oatexec && (::strcmp(symbol_name, "oatdata") == 0 ||
2087                                  ::strcmp(symbol_name, "oatexec") == 0))
2088       continue;
2089 
2090     SectionSP symbol_section_sp;
2091     SymbolType symbol_type = eSymbolTypeInvalid;
2092     Elf64_Half section_idx = symbol.st_shndx;
2093 
2094     switch (section_idx) {
2095     case SHN_ABS:
2096       symbol_type = eSymbolTypeAbsolute;
2097       break;
2098     case SHN_UNDEF:
2099       symbol_type = eSymbolTypeUndefined;
2100       break;
2101     default:
2102       symbol_section_sp = section_list->GetSectionAtIndex(section_idx);
2103       break;
2104     }
2105 
2106     // If a symbol is undefined do not process it further even if it has a STT
2107     // type
2108     if (symbol_type != eSymbolTypeUndefined) {
2109       switch (symbol.getType()) {
2110       default:
2111       case STT_NOTYPE:
2112         // The symbol's type is not specified.
2113         break;
2114 
2115       case STT_OBJECT:
2116         // The symbol is associated with a data object, such as a variable, an
2117         // array, etc.
2118         symbol_type = eSymbolTypeData;
2119         break;
2120 
2121       case STT_FUNC:
2122         // The symbol is associated with a function or other executable code.
2123         symbol_type = eSymbolTypeCode;
2124         break;
2125 
2126       case STT_SECTION:
2127         // The symbol is associated with a section. Symbol table entries of
2128         // this type exist primarily for relocation and normally have STB_LOCAL
2129         // binding.
2130         break;
2131 
2132       case STT_FILE:
2133         // Conventionally, the symbol's name gives the name of the source file
2134         // associated with the object file. A file symbol has STB_LOCAL
2135         // binding, its section index is SHN_ABS, and it precedes the other
2136         // STB_LOCAL symbols for the file, if it is present.
2137         symbol_type = eSymbolTypeSourceFile;
2138         break;
2139 
2140       case STT_GNU_IFUNC:
2141         // The symbol is associated with an indirect function. The actual
2142         // function will be resolved if it is referenced.
2143         symbol_type = eSymbolTypeResolver;
2144         break;
2145       }
2146     }
2147 
2148     if (symbol_type == eSymbolTypeInvalid && symbol.getType() != STT_SECTION) {
2149       if (symbol_section_sp) {
2150         const ConstString &sect_name = symbol_section_sp->GetName();
2151         if (sect_name == text_section_name || sect_name == init_section_name ||
2152             sect_name == fini_section_name || sect_name == ctors_section_name ||
2153             sect_name == dtors_section_name) {
2154           symbol_type = eSymbolTypeCode;
2155         } else if (sect_name == data_section_name ||
2156                    sect_name == data2_section_name ||
2157                    sect_name == rodata_section_name ||
2158                    sect_name == rodata1_section_name ||
2159                    sect_name == bss_section_name) {
2160           symbol_type = eSymbolTypeData;
2161         }
2162       }
2163     }
2164 
2165     int64_t symbol_value_offset = 0;
2166     uint32_t additional_flags = 0;
2167 
2168     if (arch.IsValid()) {
2169       if (arch.GetMachine() == llvm::Triple::arm) {
2170         if (symbol.getBinding() == STB_LOCAL) {
2171           char mapping_symbol = FindArmAarch64MappingSymbol(symbol_name);
2172           if (symbol_type == eSymbolTypeCode) {
2173             switch (mapping_symbol) {
2174             case 'a':
2175               // $a[.<any>]* - marks an ARM instruction sequence
2176               m_address_class_map[symbol.st_value] = AddressClass::eCode;
2177               break;
2178             case 'b':
2179             case 't':
2180               // $b[.<any>]* - marks a THUMB BL instruction sequence
2181               // $t[.<any>]* - marks a THUMB instruction sequence
2182               m_address_class_map[symbol.st_value] =
2183                   AddressClass::eCodeAlternateISA;
2184               break;
2185             case 'd':
2186               // $d[.<any>]* - marks a data item sequence (e.g. lit pool)
2187               m_address_class_map[symbol.st_value] = AddressClass::eData;
2188               break;
2189             }
2190           }
2191           if (mapping_symbol)
2192             continue;
2193         }
2194       } else if (arch.GetMachine() == llvm::Triple::aarch64) {
2195         if (symbol.getBinding() == STB_LOCAL) {
2196           char mapping_symbol = FindArmAarch64MappingSymbol(symbol_name);
2197           if (symbol_type == eSymbolTypeCode) {
2198             switch (mapping_symbol) {
2199             case 'x':
2200               // $x[.<any>]* - marks an A64 instruction sequence
2201               m_address_class_map[symbol.st_value] = AddressClass::eCode;
2202               break;
2203             case 'd':
2204               // $d[.<any>]* - marks a data item sequence (e.g. lit pool)
2205               m_address_class_map[symbol.st_value] = AddressClass::eData;
2206               break;
2207             }
2208           }
2209           if (mapping_symbol)
2210             continue;
2211         }
2212       }
2213 
2214       if (arch.GetMachine() == llvm::Triple::arm) {
2215         if (symbol_type == eSymbolTypeCode) {
2216           if (symbol.st_value & 1) {
2217             // Subtracting 1 from the address effectively unsets the low order
2218             // bit, which results in the address actually pointing to the
2219             // beginning of the symbol. This delta will be used below in
2220             // conjunction with symbol.st_value to produce the final
2221             // symbol_value that we store in the symtab.
2222             symbol_value_offset = -1;
2223             m_address_class_map[symbol.st_value ^ 1] =
2224                 AddressClass::eCodeAlternateISA;
2225           } else {
2226             // This address is ARM
2227             m_address_class_map[symbol.st_value] = AddressClass::eCode;
2228           }
2229         }
2230       }
2231 
2232       /*
2233        * MIPS:
2234        * The bit #0 of an address is used for ISA mode (1 for microMIPS, 0 for
2235        * MIPS).
2236        * This allows processor to switch between microMIPS and MIPS without any
2237        * need
2238        * for special mode-control register. However, apart from .debug_line,
2239        * none of
2240        * the ELF/DWARF sections set the ISA bit (for symbol or section). Use
2241        * st_other
2242        * flag to check whether the symbol is microMIPS and then set the address
2243        * class
2244        * accordingly.
2245       */
2246       const llvm::Triple::ArchType llvm_arch = arch.GetMachine();
2247       if (llvm_arch == llvm::Triple::mips ||
2248           llvm_arch == llvm::Triple::mipsel ||
2249           llvm_arch == llvm::Triple::mips64 ||
2250           llvm_arch == llvm::Triple::mips64el) {
2251         if (IS_MICROMIPS(symbol.st_other))
2252           m_address_class_map[symbol.st_value] = AddressClass::eCodeAlternateISA;
2253         else if ((symbol.st_value & 1) && (symbol_type == eSymbolTypeCode)) {
2254           symbol.st_value = symbol.st_value & (~1ull);
2255           m_address_class_map[symbol.st_value] = AddressClass::eCodeAlternateISA;
2256         } else {
2257           if (symbol_type == eSymbolTypeCode)
2258             m_address_class_map[symbol.st_value] = AddressClass::eCode;
2259           else if (symbol_type == eSymbolTypeData)
2260             m_address_class_map[symbol.st_value] = AddressClass::eData;
2261           else
2262             m_address_class_map[symbol.st_value] = AddressClass::eUnknown;
2263         }
2264       }
2265     }
2266 
2267     // symbol_value_offset may contain 0 for ARM symbols or -1 for THUMB
2268     // symbols. See above for more details.
2269     uint64_t symbol_value = symbol.st_value + symbol_value_offset;
2270 
2271     if (symbol_section_sp == nullptr && section_idx == SHN_ABS &&
2272         symbol.st_size != 0) {
2273       // We don't have a section for a symbol with non-zero size. Create a new
2274       // section for it so the address range covered by the symbol is also
2275       // covered by the module (represented through the section list). It is
2276       // needed so module lookup for the addresses covered by this symbol will
2277       // be successfull. This case happens for absolute symbols.
2278       ConstString fake_section_name(std::string(".absolute.") + symbol_name);
2279       symbol_section_sp =
2280           std::make_shared<Section>(module_sp, this, SHN_ABS, fake_section_name,
2281                                     eSectionTypeAbsoluteAddress, symbol_value,
2282                                     symbol.st_size, 0, 0, 0, SHF_ALLOC);
2283 
2284       module_section_list->AddSection(symbol_section_sp);
2285       section_list->AddSection(symbol_section_sp);
2286     }
2287 
2288     if (symbol_section_sp &&
2289         CalculateType() != ObjectFile::Type::eTypeObjectFile)
2290       symbol_value -= symbol_section_sp->GetFileAddress();
2291 
2292     if (symbol_section_sp && module_section_list &&
2293         module_section_list != section_list) {
2294       const ConstString &sect_name = symbol_section_sp->GetName();
2295       auto section_it = section_name_to_section.find(sect_name.GetCString());
2296       if (section_it == section_name_to_section.end())
2297         section_it =
2298             section_name_to_section
2299                 .emplace(sect_name.GetCString(),
2300                          module_section_list->FindSectionByName(sect_name))
2301                 .first;
2302       if (section_it->second)
2303         symbol_section_sp = section_it->second;
2304     }
2305 
2306     bool is_global = symbol.getBinding() == STB_GLOBAL;
2307     uint32_t flags = symbol.st_other << 8 | symbol.st_info | additional_flags;
2308     bool is_mangled = (symbol_name[0] == '_' && symbol_name[1] == 'Z');
2309 
2310     llvm::StringRef symbol_ref(symbol_name);
2311 
2312     // Symbol names may contain @VERSION suffixes. Find those and strip them
2313     // temporarily.
2314     size_t version_pos = symbol_ref.find('@');
2315     bool has_suffix = version_pos != llvm::StringRef::npos;
2316     llvm::StringRef symbol_bare = symbol_ref.substr(0, version_pos);
2317     Mangled mangled(ConstString(symbol_bare), is_mangled);
2318 
2319     // Now append the suffix back to mangled and unmangled names. Only do it if
2320     // the demangling was successful (string is not empty).
2321     if (has_suffix) {
2322       llvm::StringRef suffix = symbol_ref.substr(version_pos);
2323 
2324       llvm::StringRef mangled_name = mangled.GetMangledName().GetStringRef();
2325       if (!mangled_name.empty())
2326         mangled.SetMangledName(ConstString((mangled_name + suffix).str()));
2327 
2328       ConstString demangled =
2329           mangled.GetDemangledName(lldb::eLanguageTypeUnknown);
2330       llvm::StringRef demangled_name = demangled.GetStringRef();
2331       if (!demangled_name.empty())
2332         mangled.SetDemangledName(ConstString((demangled_name + suffix).str()));
2333     }
2334 
2335     // In ELF all symbol should have a valid size but it is not true for some
2336     // function symbols coming from hand written assembly. As none of the
2337     // function symbol should have 0 size we try to calculate the size for
2338     // these symbols in the symtab with saying that their original size is not
2339     // valid.
2340     bool symbol_size_valid =
2341         symbol.st_size != 0 || symbol.getType() != STT_FUNC;
2342 
2343     Symbol dc_symbol(
2344         i + start_id, // ID is the original symbol table index.
2345         mangled,
2346         symbol_type,                    // Type of this symbol
2347         is_global,                      // Is this globally visible?
2348         false,                          // Is this symbol debug info?
2349         false,                          // Is this symbol a trampoline?
2350         false,                          // Is this symbol artificial?
2351         AddressRange(symbol_section_sp, // Section in which this symbol is
2352                                         // defined or null.
2353                      symbol_value,      // Offset in section or symbol value.
2354                      symbol.st_size),   // Size in bytes of this symbol.
2355         symbol_size_valid,              // Symbol size is valid
2356         has_suffix,                     // Contains linker annotations?
2357         flags);                         // Symbol flags.
2358     symtab->AddSymbol(dc_symbol);
2359   }
2360   return i;
2361 }
2362 
2363 unsigned ObjectFileELF::ParseSymbolTable(Symtab *symbol_table,
2364                                          user_id_t start_id,
2365                                          lldb_private::Section *symtab) {
2366   if (symtab->GetObjectFile() != this) {
2367     // If the symbol table section is owned by a different object file, have it
2368     // do the parsing.
2369     ObjectFileELF *obj_file_elf =
2370         static_cast<ObjectFileELF *>(symtab->GetObjectFile());
2371     return obj_file_elf->ParseSymbolTable(symbol_table, start_id, symtab);
2372   }
2373 
2374   // Get section list for this object file.
2375   SectionList *section_list = m_sections_ap.get();
2376   if (!section_list)
2377     return 0;
2378 
2379   user_id_t symtab_id = symtab->GetID();
2380   const ELFSectionHeaderInfo *symtab_hdr = GetSectionHeaderByIndex(symtab_id);
2381   assert(symtab_hdr->sh_type == SHT_SYMTAB ||
2382          symtab_hdr->sh_type == SHT_DYNSYM);
2383 
2384   // sh_link: section header index of associated string table. Section ID's are
2385   // ones based.
2386   user_id_t strtab_id = symtab_hdr->sh_link + 1;
2387   Section *strtab = section_list->FindSectionByID(strtab_id).get();
2388 
2389   if (symtab && strtab) {
2390     assert(symtab->GetObjectFile() == this);
2391     assert(strtab->GetObjectFile() == this);
2392 
2393     DataExtractor symtab_data;
2394     DataExtractor strtab_data;
2395     if (ReadSectionData(symtab, symtab_data) &&
2396         ReadSectionData(strtab, strtab_data)) {
2397       size_t num_symbols = symtab_data.GetByteSize() / symtab_hdr->sh_entsize;
2398 
2399       return ParseSymbols(symbol_table, start_id, section_list, num_symbols,
2400                           symtab_data, strtab_data);
2401     }
2402   }
2403 
2404   return 0;
2405 }
2406 
2407 size_t ObjectFileELF::ParseDynamicSymbols() {
2408   if (m_dynamic_symbols.size())
2409     return m_dynamic_symbols.size();
2410 
2411   SectionList *section_list = GetSectionList();
2412   if (!section_list)
2413     return 0;
2414 
2415   // Find the SHT_DYNAMIC section.
2416   Section *dynsym =
2417       section_list->FindSectionByType(eSectionTypeELFDynamicLinkInfo, true)
2418           .get();
2419   if (!dynsym)
2420     return 0;
2421   assert(dynsym->GetObjectFile() == this);
2422 
2423   ELFDynamic symbol;
2424   DataExtractor dynsym_data;
2425   if (ReadSectionData(dynsym, dynsym_data)) {
2426     const lldb::offset_t section_size = dynsym_data.GetByteSize();
2427     lldb::offset_t cursor = 0;
2428 
2429     while (cursor < section_size) {
2430       if (!symbol.Parse(dynsym_data, &cursor))
2431         break;
2432 
2433       m_dynamic_symbols.push_back(symbol);
2434     }
2435   }
2436 
2437   return m_dynamic_symbols.size();
2438 }
2439 
2440 const ELFDynamic *ObjectFileELF::FindDynamicSymbol(unsigned tag) {
2441   if (!ParseDynamicSymbols())
2442     return NULL;
2443 
2444   DynamicSymbolCollIter I = m_dynamic_symbols.begin();
2445   DynamicSymbolCollIter E = m_dynamic_symbols.end();
2446   for (; I != E; ++I) {
2447     ELFDynamic *symbol = &*I;
2448 
2449     if (symbol->d_tag == tag)
2450       return symbol;
2451   }
2452 
2453   return NULL;
2454 }
2455 
2456 unsigned ObjectFileELF::PLTRelocationType() {
2457   // DT_PLTREL
2458   //  This member specifies the type of relocation entry to which the
2459   //  procedure linkage table refers. The d_val member holds DT_REL or
2460   //  DT_RELA, as appropriate. All relocations in a procedure linkage table
2461   //  must use the same relocation.
2462   const ELFDynamic *symbol = FindDynamicSymbol(DT_PLTREL);
2463 
2464   if (symbol)
2465     return symbol->d_val;
2466 
2467   return 0;
2468 }
2469 
2470 // Returns the size of the normal plt entries and the offset of the first
2471 // normal plt entry. The 0th entry in the plt table is usually a resolution
2472 // entry which have different size in some architectures then the rest of the
2473 // plt entries.
2474 static std::pair<uint64_t, uint64_t>
2475 GetPltEntrySizeAndOffset(const ELFSectionHeader *rel_hdr,
2476                          const ELFSectionHeader *plt_hdr) {
2477   const elf_xword num_relocations = rel_hdr->sh_size / rel_hdr->sh_entsize;
2478 
2479   // Clang 3.3 sets entsize to 4 for 32-bit binaries, but the plt entries are
2480   // 16 bytes. So round the entsize up by the alignment if addralign is set.
2481   elf_xword plt_entsize =
2482       plt_hdr->sh_addralign
2483           ? llvm::alignTo(plt_hdr->sh_entsize, plt_hdr->sh_addralign)
2484           : plt_hdr->sh_entsize;
2485 
2486   // Some linkers e.g ld for arm, fill plt_hdr->sh_entsize field incorrectly.
2487   // PLT entries relocation code in general requires multiple instruction and
2488   // should be greater than 4 bytes in most cases. Try to guess correct size
2489   // just in case.
2490   if (plt_entsize <= 4) {
2491     // The linker haven't set the plt_hdr->sh_entsize field. Try to guess the
2492     // size of the plt entries based on the number of entries and the size of
2493     // the plt section with the assumption that the size of the 0th entry is at
2494     // least as big as the size of the normal entries and it isn't much bigger
2495     // then that.
2496     if (plt_hdr->sh_addralign)
2497       plt_entsize = plt_hdr->sh_size / plt_hdr->sh_addralign /
2498                     (num_relocations + 1) * plt_hdr->sh_addralign;
2499     else
2500       plt_entsize = plt_hdr->sh_size / (num_relocations + 1);
2501   }
2502 
2503   elf_xword plt_offset = plt_hdr->sh_size - num_relocations * plt_entsize;
2504 
2505   return std::make_pair(plt_entsize, plt_offset);
2506 }
2507 
2508 static unsigned ParsePLTRelocations(
2509     Symtab *symbol_table, user_id_t start_id, unsigned rel_type,
2510     const ELFHeader *hdr, const ELFSectionHeader *rel_hdr,
2511     const ELFSectionHeader *plt_hdr, const ELFSectionHeader *sym_hdr,
2512     const lldb::SectionSP &plt_section_sp, DataExtractor &rel_data,
2513     DataExtractor &symtab_data, DataExtractor &strtab_data) {
2514   ELFRelocation rel(rel_type);
2515   ELFSymbol symbol;
2516   lldb::offset_t offset = 0;
2517 
2518   uint64_t plt_offset, plt_entsize;
2519   std::tie(plt_entsize, plt_offset) =
2520       GetPltEntrySizeAndOffset(rel_hdr, plt_hdr);
2521   const elf_xword num_relocations = rel_hdr->sh_size / rel_hdr->sh_entsize;
2522 
2523   typedef unsigned (*reloc_info_fn)(const ELFRelocation &rel);
2524   reloc_info_fn reloc_type;
2525   reloc_info_fn reloc_symbol;
2526 
2527   if (hdr->Is32Bit()) {
2528     reloc_type = ELFRelocation::RelocType32;
2529     reloc_symbol = ELFRelocation::RelocSymbol32;
2530   } else {
2531     reloc_type = ELFRelocation::RelocType64;
2532     reloc_symbol = ELFRelocation::RelocSymbol64;
2533   }
2534 
2535   unsigned slot_type = hdr->GetRelocationJumpSlotType();
2536   unsigned i;
2537   for (i = 0; i < num_relocations; ++i) {
2538     if (rel.Parse(rel_data, &offset) == false)
2539       break;
2540 
2541     if (reloc_type(rel) != slot_type)
2542       continue;
2543 
2544     lldb::offset_t symbol_offset = reloc_symbol(rel) * sym_hdr->sh_entsize;
2545     if (!symbol.Parse(symtab_data, &symbol_offset))
2546       break;
2547 
2548     const char *symbol_name = strtab_data.PeekCStr(symbol.st_name);
2549     bool is_mangled =
2550         symbol_name ? (symbol_name[0] == '_' && symbol_name[1] == 'Z') : false;
2551     uint64_t plt_index = plt_offset + i * plt_entsize;
2552 
2553     Symbol jump_symbol(
2554         i + start_id,          // Symbol table index
2555         symbol_name,           // symbol name.
2556         is_mangled,            // is the symbol name mangled?
2557         eSymbolTypeTrampoline, // Type of this symbol
2558         false,                 // Is this globally visible?
2559         false,                 // Is this symbol debug info?
2560         true,                  // Is this symbol a trampoline?
2561         true,                  // Is this symbol artificial?
2562         plt_section_sp, // Section in which this symbol is defined or null.
2563         plt_index,      // Offset in section or symbol value.
2564         plt_entsize,    // Size in bytes of this symbol.
2565         true,           // Size is valid
2566         false,          // Contains linker annotations?
2567         0);             // Symbol flags.
2568 
2569     symbol_table->AddSymbol(jump_symbol);
2570   }
2571 
2572   return i;
2573 }
2574 
2575 unsigned
2576 ObjectFileELF::ParseTrampolineSymbols(Symtab *symbol_table, user_id_t start_id,
2577                                       const ELFSectionHeaderInfo *rel_hdr,
2578                                       user_id_t rel_id) {
2579   assert(rel_hdr->sh_type == SHT_RELA || rel_hdr->sh_type == SHT_REL);
2580 
2581   // The link field points to the associated symbol table.
2582   user_id_t symtab_id = rel_hdr->sh_link;
2583 
2584   // If the link field doesn't point to the appropriate symbol name table then
2585   // try to find it by name as some compiler don't fill in the link fields.
2586   if (!symtab_id)
2587     symtab_id = GetSectionIndexByName(".dynsym");
2588 
2589   // Get PLT section.  We cannot use rel_hdr->sh_info, since current linkers
2590   // point that to the .got.plt or .got section instead of .plt.
2591   user_id_t plt_id = GetSectionIndexByName(".plt");
2592 
2593   if (!symtab_id || !plt_id)
2594     return 0;
2595 
2596   // Section ID's are ones based;
2597   symtab_id++;
2598   plt_id++;
2599 
2600   const ELFSectionHeaderInfo *plt_hdr = GetSectionHeaderByIndex(plt_id);
2601   if (!plt_hdr)
2602     return 0;
2603 
2604   const ELFSectionHeaderInfo *sym_hdr = GetSectionHeaderByIndex(symtab_id);
2605   if (!sym_hdr)
2606     return 0;
2607 
2608   SectionList *section_list = m_sections_ap.get();
2609   if (!section_list)
2610     return 0;
2611 
2612   Section *rel_section = section_list->FindSectionByID(rel_id).get();
2613   if (!rel_section)
2614     return 0;
2615 
2616   SectionSP plt_section_sp(section_list->FindSectionByID(plt_id));
2617   if (!plt_section_sp)
2618     return 0;
2619 
2620   Section *symtab = section_list->FindSectionByID(symtab_id).get();
2621   if (!symtab)
2622     return 0;
2623 
2624   // sh_link points to associated string table.
2625   Section *strtab = section_list->FindSectionByID(sym_hdr->sh_link + 1).get();
2626   if (!strtab)
2627     return 0;
2628 
2629   DataExtractor rel_data;
2630   if (!ReadSectionData(rel_section, rel_data))
2631     return 0;
2632 
2633   DataExtractor symtab_data;
2634   if (!ReadSectionData(symtab, symtab_data))
2635     return 0;
2636 
2637   DataExtractor strtab_data;
2638   if (!ReadSectionData(strtab, strtab_data))
2639     return 0;
2640 
2641   unsigned rel_type = PLTRelocationType();
2642   if (!rel_type)
2643     return 0;
2644 
2645   return ParsePLTRelocations(symbol_table, start_id, rel_type, &m_header,
2646                              rel_hdr, plt_hdr, sym_hdr, plt_section_sp,
2647                              rel_data, symtab_data, strtab_data);
2648 }
2649 
2650 unsigned ObjectFileELF::ApplyRelocations(
2651     Symtab *symtab, const ELFHeader *hdr, const ELFSectionHeader *rel_hdr,
2652     const ELFSectionHeader *symtab_hdr, const ELFSectionHeader *debug_hdr,
2653     DataExtractor &rel_data, DataExtractor &symtab_data,
2654     DataExtractor &debug_data, Section *rel_section) {
2655   ELFRelocation rel(rel_hdr->sh_type);
2656   lldb::addr_t offset = 0;
2657   const unsigned num_relocations = rel_hdr->sh_size / rel_hdr->sh_entsize;
2658   typedef unsigned (*reloc_info_fn)(const ELFRelocation &rel);
2659   reloc_info_fn reloc_type;
2660   reloc_info_fn reloc_symbol;
2661 
2662   if (hdr->Is32Bit()) {
2663     reloc_type = ELFRelocation::RelocType32;
2664     reloc_symbol = ELFRelocation::RelocSymbol32;
2665   } else {
2666     reloc_type = ELFRelocation::RelocType64;
2667     reloc_symbol = ELFRelocation::RelocSymbol64;
2668   }
2669 
2670   for (unsigned i = 0; i < num_relocations; ++i) {
2671     if (rel.Parse(rel_data, &offset) == false)
2672       break;
2673 
2674     Symbol *symbol = NULL;
2675 
2676     if (hdr->Is32Bit()) {
2677       switch (reloc_type(rel)) {
2678       case R_386_32:
2679       case R_386_PC32:
2680       default:
2681         // FIXME: This asserts with this input:
2682         //
2683         // foo.cpp
2684         // int main(int argc, char **argv) { return 0; }
2685         //
2686         // clang++.exe --target=i686-unknown-linux-gnu -g -c foo.cpp -o foo.o
2687         //
2688         // and running this on the foo.o module.
2689         assert(false && "unexpected relocation type");
2690       }
2691     } else {
2692       switch (reloc_type(rel)) {
2693       case R_X86_64_64: {
2694         symbol = symtab->FindSymbolByID(reloc_symbol(rel));
2695         if (symbol) {
2696           addr_t value = symbol->GetAddressRef().GetFileAddress();
2697           DataBufferSP &data_buffer_sp = debug_data.GetSharedDataBuffer();
2698           uint64_t *dst = reinterpret_cast<uint64_t *>(
2699               data_buffer_sp->GetBytes() + rel_section->GetFileOffset() +
2700               ELFRelocation::RelocOffset64(rel));
2701           *dst = value + ELFRelocation::RelocAddend64(rel);
2702         }
2703         break;
2704       }
2705       case R_X86_64_32:
2706       case R_X86_64_32S:
2707       case R_AARCH64_ABS32: {
2708         symbol = symtab->FindSymbolByID(reloc_symbol(rel));
2709         if (symbol) {
2710           addr_t value = symbol->GetAddressRef().GetFileAddress();
2711           value += ELFRelocation::RelocAddend32(rel);
2712           if ((reloc_type(rel) == R_X86_64_32 && (value <= UINT32_MAX)) ||
2713               (reloc_type(rel) == R_X86_64_32S &&
2714                ((int64_t)value <= INT32_MAX && (int64_t)value >= INT32_MIN)) ||
2715               (reloc_type(rel) == R_AARCH64_ABS32 && (value <= UINT32_MAX))) {
2716             Log *log =
2717                 lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_MODULES);
2718             log->Printf("Failed to apply debug info relocations");
2719           }
2720           uint32_t truncated_addr = (value & 0xFFFFFFFF);
2721           DataBufferSP &data_buffer_sp = debug_data.GetSharedDataBuffer();
2722           uint32_t *dst = reinterpret_cast<uint32_t *>(
2723               data_buffer_sp->GetBytes() + rel_section->GetFileOffset() +
2724               ELFRelocation::RelocOffset32(rel));
2725           *dst = truncated_addr;
2726         }
2727         break;
2728       }
2729       case R_X86_64_PC32:
2730       default:
2731         assert(false && "unexpected relocation type");
2732       }
2733     }
2734   }
2735 
2736   return 0;
2737 }
2738 
2739 unsigned ObjectFileELF::RelocateDebugSections(const ELFSectionHeader *rel_hdr,
2740                                               user_id_t rel_id,
2741                                               lldb_private::Symtab *thetab) {
2742   assert(rel_hdr->sh_type == SHT_RELA || rel_hdr->sh_type == SHT_REL);
2743 
2744   // Parse in the section list if needed.
2745   SectionList *section_list = GetSectionList();
2746   if (!section_list)
2747     return 0;
2748 
2749   // Section ID's are ones based.
2750   user_id_t symtab_id = rel_hdr->sh_link + 1;
2751   user_id_t debug_id = rel_hdr->sh_info + 1;
2752 
2753   const ELFSectionHeader *symtab_hdr = GetSectionHeaderByIndex(symtab_id);
2754   if (!symtab_hdr)
2755     return 0;
2756 
2757   const ELFSectionHeader *debug_hdr = GetSectionHeaderByIndex(debug_id);
2758   if (!debug_hdr)
2759     return 0;
2760 
2761   Section *rel = section_list->FindSectionByID(rel_id).get();
2762   if (!rel)
2763     return 0;
2764 
2765   Section *symtab = section_list->FindSectionByID(symtab_id).get();
2766   if (!symtab)
2767     return 0;
2768 
2769   Section *debug = section_list->FindSectionByID(debug_id).get();
2770   if (!debug)
2771     return 0;
2772 
2773   DataExtractor rel_data;
2774   DataExtractor symtab_data;
2775   DataExtractor debug_data;
2776 
2777   if (GetData(rel->GetFileOffset(), rel->GetFileSize(), rel_data) &&
2778       GetData(symtab->GetFileOffset(), symtab->GetFileSize(), symtab_data) &&
2779       GetData(debug->GetFileOffset(), debug->GetFileSize(), debug_data)) {
2780     ApplyRelocations(thetab, &m_header, rel_hdr, symtab_hdr, debug_hdr,
2781                      rel_data, symtab_data, debug_data, debug);
2782   }
2783 
2784   return 0;
2785 }
2786 
2787 Symtab *ObjectFileELF::GetSymtab() {
2788   ModuleSP module_sp(GetModule());
2789   if (!module_sp)
2790     return NULL;
2791 
2792   // We always want to use the main object file so we (hopefully) only have one
2793   // cached copy of our symtab, dynamic sections, etc.
2794   ObjectFile *module_obj_file = module_sp->GetObjectFile();
2795   if (module_obj_file && module_obj_file != this)
2796     return module_obj_file->GetSymtab();
2797 
2798   if (m_symtab_ap.get() == NULL) {
2799     SectionList *section_list = module_sp->GetSectionList();
2800     if (!section_list)
2801       return NULL;
2802 
2803     uint64_t symbol_id = 0;
2804     std::lock_guard<std::recursive_mutex> guard(module_sp->GetMutex());
2805 
2806     // Sharable objects and dynamic executables usually have 2 distinct symbol
2807     // tables, one named ".symtab", and the other ".dynsym". The dynsym is a
2808     // smaller version of the symtab that only contains global symbols. The
2809     // information found in the dynsym is therefore also found in the symtab,
2810     // while the reverse is not necessarily true.
2811     Section *symtab =
2812         section_list->FindSectionByType(eSectionTypeELFSymbolTable, true).get();
2813     if (!symtab) {
2814       // The symtab section is non-allocable and can be stripped, so if it
2815       // doesn't exist then use the dynsym section which should always be
2816       // there.
2817       symtab =
2818           section_list->FindSectionByType(eSectionTypeELFDynamicSymbols, true)
2819               .get();
2820     }
2821     if (symtab) {
2822       m_symtab_ap.reset(new Symtab(symtab->GetObjectFile()));
2823       symbol_id += ParseSymbolTable(m_symtab_ap.get(), symbol_id, symtab);
2824     }
2825 
2826     // DT_JMPREL
2827     //      If present, this entry's d_ptr member holds the address of
2828     //      relocation
2829     //      entries associated solely with the procedure linkage table.
2830     //      Separating
2831     //      these relocation entries lets the dynamic linker ignore them during
2832     //      process initialization, if lazy binding is enabled. If this entry is
2833     //      present, the related entries of types DT_PLTRELSZ and DT_PLTREL must
2834     //      also be present.
2835     const ELFDynamic *symbol = FindDynamicSymbol(DT_JMPREL);
2836     if (symbol) {
2837       // Synthesize trampoline symbols to help navigate the PLT.
2838       addr_t addr = symbol->d_ptr;
2839       Section *reloc_section =
2840           section_list->FindSectionContainingFileAddress(addr).get();
2841       if (reloc_section) {
2842         user_id_t reloc_id = reloc_section->GetID();
2843         const ELFSectionHeaderInfo *reloc_header =
2844             GetSectionHeaderByIndex(reloc_id);
2845         assert(reloc_header);
2846 
2847         if (m_symtab_ap == nullptr)
2848           m_symtab_ap.reset(new Symtab(reloc_section->GetObjectFile()));
2849 
2850         ParseTrampolineSymbols(m_symtab_ap.get(), symbol_id, reloc_header,
2851                                reloc_id);
2852       }
2853     }
2854 
2855     DWARFCallFrameInfo *eh_frame = GetUnwindTable().GetEHFrameInfo();
2856     if (eh_frame) {
2857       if (m_symtab_ap == nullptr)
2858         m_symtab_ap.reset(new Symtab(this));
2859       ParseUnwindSymbols(m_symtab_ap.get(), eh_frame);
2860     }
2861 
2862     // If we still don't have any symtab then create an empty instance to avoid
2863     // do the section lookup next time.
2864     if (m_symtab_ap == nullptr)
2865       m_symtab_ap.reset(new Symtab(this));
2866 
2867     m_symtab_ap->CalculateSymbolSizes();
2868   }
2869 
2870   return m_symtab_ap.get();
2871 }
2872 
2873 void ObjectFileELF::RelocateSection(lldb_private::Section *section)
2874 {
2875   static const char *debug_prefix = ".debug";
2876 
2877   // Set relocated bit so we stop getting called, regardless of whether we
2878   // actually relocate.
2879   section->SetIsRelocated(true);
2880 
2881   // We only relocate in ELF relocatable files
2882   if (CalculateType() != eTypeObjectFile)
2883     return;
2884 
2885   const char *section_name = section->GetName().GetCString();
2886   // Can't relocate that which can't be named
2887   if (section_name == nullptr)
2888     return;
2889 
2890   // We don't relocate non-debug sections at the moment
2891   if (strncmp(section_name, debug_prefix, strlen(debug_prefix)))
2892     return;
2893 
2894   // Relocation section names to look for
2895   std::string needle = std::string(".rel") + section_name;
2896   std::string needlea = std::string(".rela") + section_name;
2897 
2898   for (SectionHeaderCollIter I = m_section_headers.begin();
2899        I != m_section_headers.end(); ++I) {
2900     if (I->sh_type == SHT_RELA || I->sh_type == SHT_REL) {
2901       const char *hay_name = I->section_name.GetCString();
2902       if (hay_name == nullptr)
2903         continue;
2904       if (needle == hay_name || needlea == hay_name) {
2905         const ELFSectionHeader &reloc_header = *I;
2906         user_id_t reloc_id = SectionIndex(I);
2907         RelocateDebugSections(&reloc_header, reloc_id, GetSymtab());
2908         break;
2909       }
2910     }
2911   }
2912 }
2913 
2914 void ObjectFileELF::ParseUnwindSymbols(Symtab *symbol_table,
2915                                        DWARFCallFrameInfo *eh_frame) {
2916   SectionList *section_list = GetSectionList();
2917   if (!section_list)
2918     return;
2919 
2920   // First we save the new symbols into a separate list and add them to the
2921   // symbol table after we colleced all symbols we want to add. This is
2922   // neccessary because adding a new symbol invalidates the internal index of
2923   // the symtab what causing the next lookup to be slow because it have to
2924   // recalculate the index first.
2925   std::vector<Symbol> new_symbols;
2926 
2927   eh_frame->ForEachFDEEntries([this, symbol_table, section_list, &new_symbols](
2928       lldb::addr_t file_addr, uint32_t size, dw_offset_t) {
2929     Symbol *symbol = symbol_table->FindSymbolAtFileAddress(file_addr);
2930     if (symbol) {
2931       if (!symbol->GetByteSizeIsValid()) {
2932         symbol->SetByteSize(size);
2933         symbol->SetSizeIsSynthesized(true);
2934       }
2935     } else {
2936       SectionSP section_sp =
2937           section_list->FindSectionContainingFileAddress(file_addr);
2938       if (section_sp) {
2939         addr_t offset = file_addr - section_sp->GetFileAddress();
2940         const char *symbol_name = GetNextSyntheticSymbolName().GetCString();
2941         uint64_t symbol_id = symbol_table->GetNumSymbols();
2942         Symbol eh_symbol(
2943             symbol_id,       // Symbol table index.
2944             symbol_name,     // Symbol name.
2945             false,           // Is the symbol name mangled?
2946             eSymbolTypeCode, // Type of this symbol.
2947             true,            // Is this globally visible?
2948             false,           // Is this symbol debug info?
2949             false,           // Is this symbol a trampoline?
2950             true,            // Is this symbol artificial?
2951             section_sp,      // Section in which this symbol is defined or null.
2952             offset,          // Offset in section or symbol value.
2953             0,     // Size:          Don't specify the size as an FDE can
2954             false, // Size is valid: cover multiple symbols.
2955             false, // Contains linker annotations?
2956             0);    // Symbol flags.
2957         new_symbols.push_back(eh_symbol);
2958       }
2959     }
2960     return true;
2961   });
2962 
2963   for (const Symbol &s : new_symbols)
2964     symbol_table->AddSymbol(s);
2965 }
2966 
2967 bool ObjectFileELF::IsStripped() {
2968   // TODO: determine this for ELF
2969   return false;
2970 }
2971 
2972 //===----------------------------------------------------------------------===//
2973 // Dump
2974 //
2975 // Dump the specifics of the runtime file container (such as any headers
2976 // segments, sections, etc).
2977 //----------------------------------------------------------------------
2978 void ObjectFileELF::Dump(Stream *s) {
2979   ModuleSP module_sp(GetModule());
2980   if (!module_sp) {
2981     return;
2982   }
2983 
2984   std::lock_guard<std::recursive_mutex> guard(module_sp->GetMutex());
2985   s->Printf("%p: ", static_cast<void *>(this));
2986   s->Indent();
2987   s->PutCString("ObjectFileELF");
2988 
2989   ArchSpec header_arch;
2990   GetArchitecture(header_arch);
2991 
2992   *s << ", file = '" << m_file
2993      << "', arch = " << header_arch.GetArchitectureName() << "\n";
2994 
2995   DumpELFHeader(s, m_header);
2996   s->EOL();
2997   DumpELFProgramHeaders(s);
2998   s->EOL();
2999   DumpELFSectionHeaders(s);
3000   s->EOL();
3001   SectionList *section_list = GetSectionList();
3002   if (section_list)
3003     section_list->Dump(s, NULL, true, UINT32_MAX);
3004   Symtab *symtab = GetSymtab();
3005   if (symtab)
3006     symtab->Dump(s, NULL, eSortOrderNone);
3007   s->EOL();
3008   DumpDependentModules(s);
3009   s->EOL();
3010 }
3011 
3012 //----------------------------------------------------------------------
3013 // DumpELFHeader
3014 //
3015 // Dump the ELF header to the specified output stream
3016 //----------------------------------------------------------------------
3017 void ObjectFileELF::DumpELFHeader(Stream *s, const ELFHeader &header) {
3018   s->PutCString("ELF Header\n");
3019   s->Printf("e_ident[EI_MAG0   ] = 0x%2.2x\n", header.e_ident[EI_MAG0]);
3020   s->Printf("e_ident[EI_MAG1   ] = 0x%2.2x '%c'\n", header.e_ident[EI_MAG1],
3021             header.e_ident[EI_MAG1]);
3022   s->Printf("e_ident[EI_MAG2   ] = 0x%2.2x '%c'\n", header.e_ident[EI_MAG2],
3023             header.e_ident[EI_MAG2]);
3024   s->Printf("e_ident[EI_MAG3   ] = 0x%2.2x '%c'\n", header.e_ident[EI_MAG3],
3025             header.e_ident[EI_MAG3]);
3026 
3027   s->Printf("e_ident[EI_CLASS  ] = 0x%2.2x\n", header.e_ident[EI_CLASS]);
3028   s->Printf("e_ident[EI_DATA   ] = 0x%2.2x ", header.e_ident[EI_DATA]);
3029   DumpELFHeader_e_ident_EI_DATA(s, header.e_ident[EI_DATA]);
3030   s->Printf("\ne_ident[EI_VERSION] = 0x%2.2x\n", header.e_ident[EI_VERSION]);
3031   s->Printf("e_ident[EI_PAD    ] = 0x%2.2x\n", header.e_ident[EI_PAD]);
3032 
3033   s->Printf("e_type      = 0x%4.4x ", header.e_type);
3034   DumpELFHeader_e_type(s, header.e_type);
3035   s->Printf("\ne_machine   = 0x%4.4x\n", header.e_machine);
3036   s->Printf("e_version   = 0x%8.8x\n", header.e_version);
3037   s->Printf("e_entry     = 0x%8.8" PRIx64 "\n", header.e_entry);
3038   s->Printf("e_phoff     = 0x%8.8" PRIx64 "\n", header.e_phoff);
3039   s->Printf("e_shoff     = 0x%8.8" PRIx64 "\n", header.e_shoff);
3040   s->Printf("e_flags     = 0x%8.8x\n", header.e_flags);
3041   s->Printf("e_ehsize    = 0x%4.4x\n", header.e_ehsize);
3042   s->Printf("e_phentsize = 0x%4.4x\n", header.e_phentsize);
3043   s->Printf("e_phnum     = 0x%8.8x\n", header.e_phnum);
3044   s->Printf("e_shentsize = 0x%4.4x\n", header.e_shentsize);
3045   s->Printf("e_shnum     = 0x%8.8x\n", header.e_shnum);
3046   s->Printf("e_shstrndx  = 0x%8.8x\n", header.e_shstrndx);
3047 }
3048 
3049 //----------------------------------------------------------------------
3050 // DumpELFHeader_e_type
3051 //
3052 // Dump an token value for the ELF header member e_type
3053 //----------------------------------------------------------------------
3054 void ObjectFileELF::DumpELFHeader_e_type(Stream *s, elf_half e_type) {
3055   switch (e_type) {
3056   case ET_NONE:
3057     *s << "ET_NONE";
3058     break;
3059   case ET_REL:
3060     *s << "ET_REL";
3061     break;
3062   case ET_EXEC:
3063     *s << "ET_EXEC";
3064     break;
3065   case ET_DYN:
3066     *s << "ET_DYN";
3067     break;
3068   case ET_CORE:
3069     *s << "ET_CORE";
3070     break;
3071   default:
3072     break;
3073   }
3074 }
3075 
3076 //----------------------------------------------------------------------
3077 // DumpELFHeader_e_ident_EI_DATA
3078 //
3079 // Dump an token value for the ELF header member e_ident[EI_DATA]
3080 //----------------------------------------------------------------------
3081 void ObjectFileELF::DumpELFHeader_e_ident_EI_DATA(Stream *s,
3082                                                   unsigned char ei_data) {
3083   switch (ei_data) {
3084   case ELFDATANONE:
3085     *s << "ELFDATANONE";
3086     break;
3087   case ELFDATA2LSB:
3088     *s << "ELFDATA2LSB - Little Endian";
3089     break;
3090   case ELFDATA2MSB:
3091     *s << "ELFDATA2MSB - Big Endian";
3092     break;
3093   default:
3094     break;
3095   }
3096 }
3097 
3098 //----------------------------------------------------------------------
3099 // DumpELFProgramHeader
3100 //
3101 // Dump a single ELF program header to the specified output stream
3102 //----------------------------------------------------------------------
3103 void ObjectFileELF::DumpELFProgramHeader(Stream *s,
3104                                          const ELFProgramHeader &ph) {
3105   DumpELFProgramHeader_p_type(s, ph.p_type);
3106   s->Printf(" %8.8" PRIx64 " %8.8" PRIx64 " %8.8" PRIx64, ph.p_offset,
3107             ph.p_vaddr, ph.p_paddr);
3108   s->Printf(" %8.8" PRIx64 " %8.8" PRIx64 " %8.8x (", ph.p_filesz, ph.p_memsz,
3109             ph.p_flags);
3110 
3111   DumpELFProgramHeader_p_flags(s, ph.p_flags);
3112   s->Printf(") %8.8" PRIx64, ph.p_align);
3113 }
3114 
3115 //----------------------------------------------------------------------
3116 // DumpELFProgramHeader_p_type
3117 //
3118 // Dump an token value for the ELF program header member p_type which describes
3119 // the type of the program header
3120 // ----------------------------------------------------------------------
3121 void ObjectFileELF::DumpELFProgramHeader_p_type(Stream *s, elf_word p_type) {
3122   const int kStrWidth = 15;
3123   switch (p_type) {
3124     CASE_AND_STREAM(s, PT_NULL, kStrWidth);
3125     CASE_AND_STREAM(s, PT_LOAD, kStrWidth);
3126     CASE_AND_STREAM(s, PT_DYNAMIC, kStrWidth);
3127     CASE_AND_STREAM(s, PT_INTERP, kStrWidth);
3128     CASE_AND_STREAM(s, PT_NOTE, kStrWidth);
3129     CASE_AND_STREAM(s, PT_SHLIB, kStrWidth);
3130     CASE_AND_STREAM(s, PT_PHDR, kStrWidth);
3131     CASE_AND_STREAM(s, PT_TLS, kStrWidth);
3132     CASE_AND_STREAM(s, PT_GNU_EH_FRAME, kStrWidth);
3133   default:
3134     s->Printf("0x%8.8x%*s", p_type, kStrWidth - 10, "");
3135     break;
3136   }
3137 }
3138 
3139 //----------------------------------------------------------------------
3140 // DumpELFProgramHeader_p_flags
3141 //
3142 // Dump an token value for the ELF program header member p_flags
3143 //----------------------------------------------------------------------
3144 void ObjectFileELF::DumpELFProgramHeader_p_flags(Stream *s, elf_word p_flags) {
3145   *s << ((p_flags & PF_X) ? "PF_X" : "    ")
3146      << (((p_flags & PF_X) && (p_flags & PF_W)) ? '+' : ' ')
3147      << ((p_flags & PF_W) ? "PF_W" : "    ")
3148      << (((p_flags & PF_W) && (p_flags & PF_R)) ? '+' : ' ')
3149      << ((p_flags & PF_R) ? "PF_R" : "    ");
3150 }
3151 
3152 //----------------------------------------------------------------------
3153 // DumpELFProgramHeaders
3154 //
3155 // Dump all of the ELF program header to the specified output stream
3156 //----------------------------------------------------------------------
3157 void ObjectFileELF::DumpELFProgramHeaders(Stream *s) {
3158   if (!ParseProgramHeaders())
3159     return;
3160 
3161   s->PutCString("Program Headers\n");
3162   s->PutCString("IDX  p_type          p_offset p_vaddr  p_paddr  "
3163                 "p_filesz p_memsz  p_flags                   p_align\n");
3164   s->PutCString("==== --------------- -------- -------- -------- "
3165                 "-------- -------- ------------------------- --------\n");
3166 
3167   uint32_t idx = 0;
3168   for (ProgramHeaderCollConstIter I = m_program_headers.begin();
3169        I != m_program_headers.end(); ++I, ++idx) {
3170     s->Printf("[%2u] ", idx);
3171     ObjectFileELF::DumpELFProgramHeader(s, *I);
3172     s->EOL();
3173   }
3174 }
3175 
3176 //----------------------------------------------------------------------
3177 // DumpELFSectionHeader
3178 //
3179 // Dump a single ELF section header to the specified output stream
3180 //----------------------------------------------------------------------
3181 void ObjectFileELF::DumpELFSectionHeader(Stream *s,
3182                                          const ELFSectionHeaderInfo &sh) {
3183   s->Printf("%8.8x ", sh.sh_name);
3184   DumpELFSectionHeader_sh_type(s, sh.sh_type);
3185   s->Printf(" %8.8" PRIx64 " (", sh.sh_flags);
3186   DumpELFSectionHeader_sh_flags(s, sh.sh_flags);
3187   s->Printf(") %8.8" PRIx64 " %8.8" PRIx64 " %8.8" PRIx64, sh.sh_addr,
3188             sh.sh_offset, sh.sh_size);
3189   s->Printf(" %8.8x %8.8x", sh.sh_link, sh.sh_info);
3190   s->Printf(" %8.8" PRIx64 " %8.8" PRIx64, sh.sh_addralign, sh.sh_entsize);
3191 }
3192 
3193 //----------------------------------------------------------------------
3194 // DumpELFSectionHeader_sh_type
3195 //
3196 // Dump an token value for the ELF section header member sh_type which
3197 // describes the type of the section
3198 //----------------------------------------------------------------------
3199 void ObjectFileELF::DumpELFSectionHeader_sh_type(Stream *s, elf_word sh_type) {
3200   const int kStrWidth = 12;
3201   switch (sh_type) {
3202     CASE_AND_STREAM(s, SHT_NULL, kStrWidth);
3203     CASE_AND_STREAM(s, SHT_PROGBITS, kStrWidth);
3204     CASE_AND_STREAM(s, SHT_SYMTAB, kStrWidth);
3205     CASE_AND_STREAM(s, SHT_STRTAB, kStrWidth);
3206     CASE_AND_STREAM(s, SHT_RELA, kStrWidth);
3207     CASE_AND_STREAM(s, SHT_HASH, kStrWidth);
3208     CASE_AND_STREAM(s, SHT_DYNAMIC, kStrWidth);
3209     CASE_AND_STREAM(s, SHT_NOTE, kStrWidth);
3210     CASE_AND_STREAM(s, SHT_NOBITS, kStrWidth);
3211     CASE_AND_STREAM(s, SHT_REL, kStrWidth);
3212     CASE_AND_STREAM(s, SHT_SHLIB, kStrWidth);
3213     CASE_AND_STREAM(s, SHT_DYNSYM, kStrWidth);
3214     CASE_AND_STREAM(s, SHT_LOPROC, kStrWidth);
3215     CASE_AND_STREAM(s, SHT_HIPROC, kStrWidth);
3216     CASE_AND_STREAM(s, SHT_LOUSER, kStrWidth);
3217     CASE_AND_STREAM(s, SHT_HIUSER, kStrWidth);
3218   default:
3219     s->Printf("0x%8.8x%*s", sh_type, kStrWidth - 10, "");
3220     break;
3221   }
3222 }
3223 
3224 //----------------------------------------------------------------------
3225 // DumpELFSectionHeader_sh_flags
3226 //
3227 // Dump an token value for the ELF section header member sh_flags
3228 //----------------------------------------------------------------------
3229 void ObjectFileELF::DumpELFSectionHeader_sh_flags(Stream *s,
3230                                                   elf_xword sh_flags) {
3231   *s << ((sh_flags & SHF_WRITE) ? "WRITE" : "     ")
3232      << (((sh_flags & SHF_WRITE) && (sh_flags & SHF_ALLOC)) ? '+' : ' ')
3233      << ((sh_flags & SHF_ALLOC) ? "ALLOC" : "     ")
3234      << (((sh_flags & SHF_ALLOC) && (sh_flags & SHF_EXECINSTR)) ? '+' : ' ')
3235      << ((sh_flags & SHF_EXECINSTR) ? "EXECINSTR" : "         ");
3236 }
3237 
3238 //----------------------------------------------------------------------
3239 // DumpELFSectionHeaders
3240 //
3241 // Dump all of the ELF section header to the specified output stream
3242 //----------------------------------------------------------------------
3243 void ObjectFileELF::DumpELFSectionHeaders(Stream *s) {
3244   if (!ParseSectionHeaders())
3245     return;
3246 
3247   s->PutCString("Section Headers\n");
3248   s->PutCString("IDX  name     type         flags                            "
3249                 "addr     offset   size     link     info     addralgn "
3250                 "entsize  Name\n");
3251   s->PutCString("==== -------- ------------ -------------------------------- "
3252                 "-------- -------- -------- -------- -------- -------- "
3253                 "-------- ====================\n");
3254 
3255   uint32_t idx = 0;
3256   for (SectionHeaderCollConstIter I = m_section_headers.begin();
3257        I != m_section_headers.end(); ++I, ++idx) {
3258     s->Printf("[%2u] ", idx);
3259     ObjectFileELF::DumpELFSectionHeader(s, *I);
3260     const char *section_name = I->section_name.AsCString("");
3261     if (section_name)
3262       *s << ' ' << section_name << "\n";
3263   }
3264 }
3265 
3266 void ObjectFileELF::DumpDependentModules(lldb_private::Stream *s) {
3267   size_t num_modules = ParseDependentModules();
3268 
3269   if (num_modules > 0) {
3270     s->PutCString("Dependent Modules:\n");
3271     for (unsigned i = 0; i < num_modules; ++i) {
3272       const FileSpec &spec = m_filespec_ap->GetFileSpecAtIndex(i);
3273       s->Printf("   %s\n", spec.GetFilename().GetCString());
3274     }
3275   }
3276 }
3277 
3278 bool ObjectFileELF::GetArchitecture(ArchSpec &arch) {
3279   if (!ParseHeader())
3280     return false;
3281 
3282   if (m_section_headers.empty()) {
3283     // Allow elf notes to be parsed which may affect the detected architecture.
3284     ParseSectionHeaders();
3285   }
3286 
3287   if (CalculateType() == eTypeCoreFile &&
3288       m_arch_spec.TripleOSIsUnspecifiedUnknown()) {
3289     // Core files don't have section headers yet they have PT_NOTE program
3290     // headers that might shed more light on the architecture
3291     if (ParseProgramHeaders()) {
3292       for (size_t i = 1, count = GetProgramHeaderCount(); i <= count; ++i) {
3293         const elf::ELFProgramHeader *header = GetProgramHeaderByIndex(i);
3294         if (header && header->p_type == PT_NOTE && header->p_offset != 0 &&
3295             header->p_filesz > 0) {
3296           DataExtractor data;
3297           if (data.SetData(m_data, header->p_offset, header->p_filesz) ==
3298               header->p_filesz) {
3299             lldb_private::UUID uuid;
3300             RefineModuleDetailsFromNote(data, m_arch_spec, uuid);
3301           }
3302         }
3303       }
3304     }
3305   }
3306   arch = m_arch_spec;
3307   return true;
3308 }
3309 
3310 ObjectFile::Type ObjectFileELF::CalculateType() {
3311   switch (m_header.e_type) {
3312   case llvm::ELF::ET_NONE:
3313     // 0 - No file type
3314     return eTypeUnknown;
3315 
3316   case llvm::ELF::ET_REL:
3317     // 1 - Relocatable file
3318     return eTypeObjectFile;
3319 
3320   case llvm::ELF::ET_EXEC:
3321     // 2 - Executable file
3322     return eTypeExecutable;
3323 
3324   case llvm::ELF::ET_DYN:
3325     // 3 - Shared object file
3326     return eTypeSharedLibrary;
3327 
3328   case ET_CORE:
3329     // 4 - Core file
3330     return eTypeCoreFile;
3331 
3332   default:
3333     break;
3334   }
3335   return eTypeUnknown;
3336 }
3337 
3338 ObjectFile::Strata ObjectFileELF::CalculateStrata() {
3339   switch (m_header.e_type) {
3340   case llvm::ELF::ET_NONE:
3341     // 0 - No file type
3342     return eStrataUnknown;
3343 
3344   case llvm::ELF::ET_REL:
3345     // 1 - Relocatable file
3346     return eStrataUnknown;
3347 
3348   case llvm::ELF::ET_EXEC:
3349     // 2 - Executable file
3350     // TODO: is there any way to detect that an executable is a kernel
3351     // related executable by inspecting the program headers, section headers,
3352     // symbols, or any other flag bits???
3353     return eStrataUser;
3354 
3355   case llvm::ELF::ET_DYN:
3356     // 3 - Shared object file
3357     // TODO: is there any way to detect that an shared library is a kernel
3358     // related executable by inspecting the program headers, section headers,
3359     // symbols, or any other flag bits???
3360     return eStrataUnknown;
3361 
3362   case ET_CORE:
3363     // 4 - Core file
3364     // TODO: is there any way to detect that an core file is a kernel
3365     // related executable by inspecting the program headers, section headers,
3366     // symbols, or any other flag bits???
3367     return eStrataUnknown;
3368 
3369   default:
3370     break;
3371   }
3372   return eStrataUnknown;
3373 }
3374 
3375 size_t ObjectFileELF::ReadSectionData(Section *section,
3376                        lldb::offset_t section_offset, void *dst,
3377                        size_t dst_len) {
3378   // If some other objectfile owns this data, pass this to them.
3379   if (section->GetObjectFile() != this)
3380     return section->GetObjectFile()->ReadSectionData(section, section_offset,
3381                                                      dst, dst_len);
3382 
3383   if (!section->Test(SHF_COMPRESSED))
3384     return ObjectFile::ReadSectionData(section, section_offset, dst, dst_len);
3385 
3386   // For compressed sections we need to read to full data to be able to
3387   // decompress.
3388   DataExtractor data;
3389   ReadSectionData(section, data);
3390   return data.CopyData(section_offset, dst_len, dst);
3391 }
3392 
3393 size_t ObjectFileELF::ReadSectionData(Section *section,
3394                                       DataExtractor &section_data) {
3395   // If some other objectfile owns this data, pass this to them.
3396   if (section->GetObjectFile() != this)
3397     return section->GetObjectFile()->ReadSectionData(section, section_data);
3398 
3399   size_t result = ObjectFile::ReadSectionData(section, section_data);
3400   if (result == 0 || !section->Test(SHF_COMPRESSED))
3401     return result;
3402 
3403   auto Decompressor = llvm::object::Decompressor::create(
3404       section->GetName().GetStringRef(),
3405       {reinterpret_cast<const char *>(section_data.GetDataStart()),
3406        size_t(section_data.GetByteSize())},
3407       GetByteOrder() == eByteOrderLittle, GetAddressByteSize() == 8);
3408   if (!Decompressor) {
3409     GetModule()->ReportWarning(
3410         "Unable to initialize decompressor for section '%s': %s",
3411         section->GetName().GetCString(),
3412         llvm::toString(Decompressor.takeError()).c_str());
3413     section_data.Clear();
3414     return 0;
3415   }
3416 
3417   auto buffer_sp =
3418       std::make_shared<DataBufferHeap>(Decompressor->getDecompressedSize(), 0);
3419   if (auto error = Decompressor->decompress(
3420           {reinterpret_cast<char *>(buffer_sp->GetBytes()),
3421            size_t(buffer_sp->GetByteSize())})) {
3422     GetModule()->ReportWarning(
3423         "Decompression of section '%s' failed: %s",
3424         section->GetName().GetCString(),
3425         llvm::toString(std::move(error)).c_str());
3426     section_data.Clear();
3427     return 0;
3428   }
3429 
3430   section_data.SetData(buffer_sp);
3431   return buffer_sp->GetByteSize();
3432 }
3433 
3434 bool ObjectFileELF::AnySegmentHasPhysicalAddress() {
3435   size_t header_count = ParseProgramHeaders();
3436   for (size_t i = 1; i <= header_count; ++i) {
3437     auto header = GetProgramHeaderByIndex(i);
3438     if (header->p_paddr != 0)
3439       return true;
3440   }
3441   return false;
3442 }
3443 
3444 std::vector<ObjectFile::LoadableData>
3445 ObjectFileELF::GetLoadableData(Target &target) {
3446   // Create a list of loadable data from loadable segments, using physical
3447   // addresses if they aren't all null
3448   std::vector<LoadableData> loadables;
3449   size_t header_count = ParseProgramHeaders();
3450   bool should_use_paddr = AnySegmentHasPhysicalAddress();
3451   for (size_t i = 1; i <= header_count; ++i) {
3452     LoadableData loadable;
3453     auto header = GetProgramHeaderByIndex(i);
3454     if (header->p_type != llvm::ELF::PT_LOAD)
3455       continue;
3456     loadable.Dest = should_use_paddr ? header->p_paddr : header->p_vaddr;
3457     if (loadable.Dest == LLDB_INVALID_ADDRESS)
3458       continue;
3459     if (header->p_filesz == 0)
3460       continue;
3461     auto segment_data = GetSegmentDataByIndex(i);
3462     loadable.Contents = llvm::ArrayRef<uint8_t>(segment_data.GetDataStart(),
3463                                                 segment_data.GetByteSize());
3464     loadables.push_back(loadable);
3465   }
3466   return loadables;
3467 }
3468