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[llvm-project.git] / llvm / tools / llvm-readobj / ARMEHABIPrinter.h
blob5f3cc7dcbfd896a05ac09c3159423aec10dcde99
1 //===--- ARMEHABIPrinter.h - ARM EHABI Unwind Information Printer ----------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8
9 #ifndef LLVM_TOOLS_LLVM_READOBJ_ARMEHABIPRINTER_H
10 #define LLVM_TOOLS_LLVM_READOBJ_ARMEHABIPRINTER_H
11
12 #include "llvm-readobj.h"
13 #include "llvm/ADT/STLExtras.h"
14 #include "llvm/Object/ELF.h"
15 #include "llvm/Object/ELFTypes.h"
16 #include "llvm/Support/ARMEHABI.h"
17 #include "llvm/Support/Debug.h"
18 #include "llvm/Support/Endian.h"
19 #include "llvm/Support/Format.h"
20 #include "llvm/Support/ScopedPrinter.h"
21 #include "llvm/Support/type_traits.h"
22
23 namespace llvm {
24 namespace ARM {
25 namespace EHABI {
26
27 class OpcodeDecoder {
28 ScopedPrinter &SW;
29 raw_ostream &OS;
30
31 struct RingEntry {
32 uint8_t Mask;
33 uint8_t Value;
34 void (OpcodeDecoder::*Routine)(const uint8_t *Opcodes, unsigned &OI);
35 };
36 static ArrayRef<RingEntry> ring();
37
38 void Decode_00xxxxxx(const uint8_t *Opcodes, unsigned &OI);
39 void Decode_01xxxxxx(const uint8_t *Opcodes, unsigned &OI);
40 void Decode_1000iiii_iiiiiiii(const uint8_t *Opcodes, unsigned &OI);
41 void Decode_10011101(const uint8_t *Opcodes, unsigned &OI);
42 void Decode_10011111(const uint8_t *Opcodes, unsigned &OI);
43 void Decode_1001nnnn(const uint8_t *Opcodes, unsigned &OI);
44 void Decode_10100nnn(const uint8_t *Opcodes, unsigned &OI);
45 void Decode_10101nnn(const uint8_t *Opcodes, unsigned &OI);
46 void Decode_10110000(const uint8_t *Opcodes, unsigned &OI);
47 void Decode_10110001_0000iiii(const uint8_t *Opcodes, unsigned &OI);
48 void Decode_10110010_uleb128(const uint8_t *Opcodes, unsigned &OI);
49 void Decode_10110011_sssscccc(const uint8_t *Opcodes, unsigned &OI);
50 void Decode_101101nn(const uint8_t *Opcodes, unsigned &OI);
51 void Decode_10111nnn(const uint8_t *Opcodes, unsigned &OI);
52 void Decode_11000110_sssscccc(const uint8_t *Opcodes, unsigned &OI);
53 void Decode_11000111_0000iiii(const uint8_t *Opcodes, unsigned &OI);
54 void Decode_11001000_sssscccc(const uint8_t *Opcodes, unsigned &OI);
55 void Decode_11001001_sssscccc(const uint8_t *Opcodes, unsigned &OI);
56 void Decode_11001yyy(const uint8_t *Opcodes, unsigned &OI);
57 void Decode_11000nnn(const uint8_t *Opcodes, unsigned &OI);
58 void Decode_11010nnn(const uint8_t *Opcodes, unsigned &OI);
59 void Decode_11xxxyyy(const uint8_t *Opcodes, unsigned &OI);
60
61 void PrintGPR(uint16_t GPRMask);
62 void PrintRegisters(uint32_t Mask, StringRef Prefix);
63
64 public:
65 OpcodeDecoder(ScopedPrinter &SW) : SW(SW), OS(SW.getOStream()) {}
66 void Decode(const uint8_t *Opcodes, off_t Offset, size_t Length);
67 };
68
69 inline ArrayRef<OpcodeDecoder::RingEntry> OpcodeDecoder::ring() {
70 static const OpcodeDecoder::RingEntry Ring[] = {
71 {0xc0, 0x00, &OpcodeDecoder::Decode_00xxxxxx},
72 {0xc0, 0x40, &OpcodeDecoder::Decode_01xxxxxx},
73 {0xf0, 0x80, &OpcodeDecoder::Decode_1000iiii_iiiiiiii},
74 {0xff, 0x9d, &OpcodeDecoder::Decode_10011101},
75 {0xff, 0x9f, &OpcodeDecoder::Decode_10011111},
76 {0xf0, 0x90, &OpcodeDecoder::Decode_1001nnnn},
77 {0xf8, 0xa0, &OpcodeDecoder::Decode_10100nnn},
78 {0xf8, 0xa8, &OpcodeDecoder::Decode_10101nnn},
79 {0xff, 0xb0, &OpcodeDecoder::Decode_10110000},
80 {0xff, 0xb1, &OpcodeDecoder::Decode_10110001_0000iiii},
81 {0xff, 0xb2, &OpcodeDecoder::Decode_10110010_uleb128},
82 {0xff, 0xb3, &OpcodeDecoder::Decode_10110011_sssscccc},
83 {0xfc, 0xb4, &OpcodeDecoder::Decode_101101nn},
84 {0xf8, 0xb8, &OpcodeDecoder::Decode_10111nnn},
85 {0xff, 0xc6, &OpcodeDecoder::Decode_11000110_sssscccc},
86 {0xff, 0xc7, &OpcodeDecoder::Decode_11000111_0000iiii},
87 {0xff, 0xc8, &OpcodeDecoder::Decode_11001000_sssscccc},
88 {0xff, 0xc9, &OpcodeDecoder::Decode_11001001_sssscccc},
89 {0xc8, 0xc8, &OpcodeDecoder::Decode_11001yyy},
90 {0xf8, 0xc0, &OpcodeDecoder::Decode_11000nnn},
91 {0xf8, 0xd0, &OpcodeDecoder::Decode_11010nnn},
92 {0xc0, 0xc0, &OpcodeDecoder::Decode_11xxxyyy},
93 };
94 return ArrayRef(Ring);
95 }
96
97 inline void OpcodeDecoder::Decode_00xxxxxx(const uint8_t *Opcodes,
98 unsigned &OI) {
99 uint8_t Opcode = Opcodes[OI++ ^ 3];
100 SW.startLine() << format("0x%02X ; vsp = vsp + %u\n", Opcode,
101 ((Opcode & 0x3f) << 2) + 4);
102 }
103 inline void OpcodeDecoder::Decode_01xxxxxx(const uint8_t *Opcodes,
104 unsigned &OI) {
105 uint8_t Opcode = Opcodes[OI++ ^ 3];
106 SW.startLine() << format("0x%02X ; vsp = vsp - %u\n", Opcode,
107 ((Opcode & 0x3f) << 2) + 4);
108 }
109 inline void OpcodeDecoder::Decode_1000iiii_iiiiiiii(const uint8_t *Opcodes,
110 unsigned &OI) {
111 uint8_t Opcode0 = Opcodes[OI++ ^ 3];
112 uint8_t Opcode1 = Opcodes[OI++ ^ 3];
113
114 uint16_t GPRMask = (Opcode1 << 4) | ((Opcode0 & 0x0f) << 12);
115 SW.startLine()
116 << format("0x%02X 0x%02X ; %s",
117 Opcode0, Opcode1, GPRMask ? "pop " : "refuse to unwind");
118 if (GPRMask)
119 PrintGPR(GPRMask);
120 OS << '\n';
121 }
122 inline void OpcodeDecoder::Decode_10011101(const uint8_t *Opcodes,
123 unsigned &OI) {
124 uint8_t Opcode = Opcodes[OI++ ^ 3];
125 SW.startLine() << format("0x%02X ; reserved (ARM MOVrr)\n", Opcode);
126 }
127 inline void OpcodeDecoder::Decode_10011111(const uint8_t *Opcodes,
128 unsigned &OI) {
129 uint8_t Opcode = Opcodes[OI++ ^ 3];
130 SW.startLine() << format("0x%02X ; reserved (WiMMX MOVrr)\n", Opcode);
131 }
132 inline void OpcodeDecoder::Decode_1001nnnn(const uint8_t *Opcodes,
133 unsigned &OI) {
134 uint8_t Opcode = Opcodes[OI++ ^ 3];
135 SW.startLine() << format("0x%02X ; vsp = r%u\n", Opcode, (Opcode & 0x0f));
136 }
137 inline void OpcodeDecoder::Decode_10100nnn(const uint8_t *Opcodes,
138 unsigned &OI) {
139 uint8_t Opcode = Opcodes[OI++ ^ 3];
140 SW.startLine() << format("0x%02X ; pop ", Opcode);
141 PrintGPR((((1 << ((Opcode & 0x7) + 1)) - 1) << 4));
142 OS << '\n';
143 }
144 inline void OpcodeDecoder::Decode_10101nnn(const uint8_t *Opcodes,
145 unsigned &OI) {
146 uint8_t Opcode = Opcodes[OI++ ^ 3];
147 SW.startLine() << format("0x%02X ; pop ", Opcode);
148 PrintGPR((((1 << ((Opcode & 0x7) + 1)) - 1) << 4) | (1 << 14));
149 OS << '\n';
150 }
151 inline void OpcodeDecoder::Decode_10110000(const uint8_t *Opcodes,
152 unsigned &OI) {
153 uint8_t Opcode = Opcodes[OI++ ^ 3];
154 SW.startLine() << format("0x%02X ; finish\n", Opcode);
155 }
156 inline void OpcodeDecoder::Decode_10110001_0000iiii(const uint8_t *Opcodes,
157 unsigned &OI) {
158 uint8_t Opcode0 = Opcodes[OI++ ^ 3];
159 uint8_t Opcode1 = Opcodes[OI++ ^ 3];
160
161 SW.startLine() << format("0x%02X 0x%02X ; %s", Opcode0, Opcode1,
162 (Opcode1 & 0xf0) ? "spare" : "pop ");
163 if (((Opcode1 & 0xf0) == 0x00) && Opcode1)
164 PrintGPR((Opcode1 & 0x0f));
165 OS << '\n';
166 }
167 inline void OpcodeDecoder::Decode_10110010_uleb128(const uint8_t *Opcodes,
168 unsigned &OI) {
169 uint8_t Opcode = Opcodes[OI++ ^ 3];
170 SW.startLine() << format("0x%02X ", Opcode);
171
172 SmallVector<uint8_t, 4> ULEB;
173 do { ULEB.push_back(Opcodes[OI ^ 3]); } while (Opcodes[OI++ ^ 3] & 0x80);
174
175 for (unsigned BI = 0, BE = ULEB.size(); BI != BE; ++BI)
176 OS << format("0x%02X ", ULEB[BI]);
177
178 uint64_t Value = 0;
179 for (unsigned BI = 0, BE = ULEB.size(); BI != BE; ++BI)
180 Value = Value | ((ULEB[BI] & 0x7f) << (7 * BI));
181
182 OS << format("; vsp = vsp + %" PRIu64 "\n", 0x204 + (Value << 2));
183 }
184 inline void OpcodeDecoder::Decode_10110011_sssscccc(const uint8_t *Opcodes,
185 unsigned &OI) {
186 uint8_t Opcode0 = Opcodes[OI++ ^ 3];
187 uint8_t Opcode1 = Opcodes[OI++ ^ 3];
188 SW.startLine() << format("0x%02X 0x%02X ; pop ", Opcode0, Opcode1);
189 uint8_t Start = ((Opcode1 & 0xf0) >> 4);
190 uint8_t Count = ((Opcode1 & 0x0f) >> 0);
191 PrintRegisters((((1 << (Count + 1)) - 1) << Start), "d");
192 OS << '\n';
193 }
194 inline void OpcodeDecoder::Decode_101101nn(const uint8_t *Opcodes,
195 unsigned &OI) {
196 uint8_t Opcode = Opcodes[OI++ ^ 3];
197 SW.startLine() << format("0x%02X ; %s\n", Opcode,
198 (Opcode == 0xb4) ? "pop ra_auth_code" : "spare");
199 }
200 inline void OpcodeDecoder::Decode_10111nnn(const uint8_t *Opcodes,
201 unsigned &OI) {
202 uint8_t Opcode = Opcodes[OI++ ^ 3];
203 SW.startLine() << format("0x%02X ; pop ", Opcode);
204 PrintRegisters((((1 << ((Opcode & 0x07) + 1)) - 1) << 8), "d");
205 OS << '\n';
206 }
207 inline void OpcodeDecoder::Decode_11000110_sssscccc(const uint8_t *Opcodes,
208 unsigned &OI) {
209 uint8_t Opcode0 = Opcodes[OI++ ^ 3];
210 uint8_t Opcode1 = Opcodes[OI++ ^ 3];
211 SW.startLine() << format("0x%02X 0x%02X ; pop ", Opcode0, Opcode1);
212 uint8_t Start = ((Opcode1 & 0xf0) >> 4);
213 uint8_t Count = ((Opcode1 & 0x0f) >> 0);
214 PrintRegisters((((1 << (Count + 1)) - 1) << Start), "wR");
215 OS << '\n';
216 }
217 inline void OpcodeDecoder::Decode_11000111_0000iiii(const uint8_t *Opcodes,
218 unsigned &OI) {
219 uint8_t Opcode0 = Opcodes[OI++ ^ 3];
220 uint8_t Opcode1 = Opcodes[OI++ ^ 3];
221 SW.startLine()
222 << format("0x%02X 0x%02X ; %s", Opcode0, Opcode1,
223 ((Opcode1 & 0xf0) || Opcode1 == 0x00) ? "spare" : "pop ");
224 if ((Opcode1 & 0xf0) == 0x00 && Opcode1)
225 PrintRegisters(Opcode1 & 0x0f, "wCGR");
226 OS << '\n';
227 }
228 inline void OpcodeDecoder::Decode_11001000_sssscccc(const uint8_t *Opcodes,
229 unsigned &OI) {
230 uint8_t Opcode0 = Opcodes[OI++ ^ 3];
231 uint8_t Opcode1 = Opcodes[OI++ ^ 3];
232 SW.startLine() << format("0x%02X 0x%02X ; pop ", Opcode0, Opcode1);
233 uint8_t Start = 16 + ((Opcode1 & 0xf0) >> 4);
234 uint8_t Count = ((Opcode1 & 0x0f) >> 0);
235 PrintRegisters((((1 << (Count + 1)) - 1) << Start), "d");
236 OS << '\n';
237 }
238 inline void OpcodeDecoder::Decode_11001001_sssscccc(const uint8_t *Opcodes,
239 unsigned &OI) {
240 uint8_t Opcode0 = Opcodes[OI++ ^ 3];
241 uint8_t Opcode1 = Opcodes[OI++ ^ 3];
242 SW.startLine() << format("0x%02X 0x%02X ; pop ", Opcode0, Opcode1);
243 uint8_t Start = ((Opcode1 & 0xf0) >> 4);
244 uint8_t Count = ((Opcode1 & 0x0f) >> 0);
245 PrintRegisters((((1 << (Count + 1)) - 1) << Start), "d");
246 OS << '\n';
247 }
248 inline void OpcodeDecoder::Decode_11001yyy(const uint8_t *Opcodes,
249 unsigned &OI) {
250 uint8_t Opcode = Opcodes[OI++ ^ 3];
251 SW.startLine() << format("0x%02X ; spare\n", Opcode);
252 }
253 inline void OpcodeDecoder::Decode_11000nnn(const uint8_t *Opcodes,
254 unsigned &OI) {
255 uint8_t Opcode = Opcodes[OI++ ^ 3];
256 SW.startLine() << format("0x%02X ; pop ", Opcode);
257 PrintRegisters((((1 << ((Opcode & 0x07) + 1)) - 1) << 10), "wR");
258 OS << '\n';
259 }
260 inline void OpcodeDecoder::Decode_11010nnn(const uint8_t *Opcodes,
261 unsigned &OI) {
262 uint8_t Opcode = Opcodes[OI++ ^ 3];
263 SW.startLine() << format("0x%02X ; pop ", Opcode);
264 PrintRegisters((((1 << ((Opcode & 0x07) + 1)) - 1) << 8), "d");
265 OS << '\n';
266 }
267 inline void OpcodeDecoder::Decode_11xxxyyy(const uint8_t *Opcodes,
268 unsigned &OI) {
269 uint8_t Opcode = Opcodes[OI++ ^ 3];
270 SW.startLine() << format("0x%02X ; spare\n", Opcode);
271 }
272
273 inline void OpcodeDecoder::PrintGPR(uint16_t GPRMask) {
274 static const char *GPRRegisterNames[16] = {
275 "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", "r8", "r9", "r10",
276 "fp", "ip", "sp", "lr", "pc"
277 };
278
279 OS << '{';
280 bool Comma = false;
281 for (unsigned RI = 0, RE = 17; RI < RE; ++RI) {
282 if (GPRMask & (1 << RI)) {
283 if (Comma)
284 OS << ", ";
285 OS << GPRRegisterNames[RI];
286 Comma = true;
287 }
288 }
289 OS << '}';
290 }
291
292 inline void OpcodeDecoder::PrintRegisters(uint32_t VFPMask, StringRef Prefix) {
293 OS << '{';
294 bool Comma = false;
295 for (unsigned RI = 0, RE = 32; RI < RE; ++RI) {
296 if (VFPMask & (1 << RI)) {
297 if (Comma)
298 OS << ", ";
299 OS << Prefix << RI;
300 Comma = true;
301 }
302 }
303 OS << '}';
304 }
305
306 inline void OpcodeDecoder::Decode(const uint8_t *Opcodes, off_t Offset,
307 size_t Length) {
308 for (unsigned OCI = Offset; OCI < Length + Offset; ) {
309 bool Decoded = false;
310 for (const auto &RE : ring()) {
311 if ((Opcodes[OCI ^ 3] & RE.Mask) == RE.Value) {
312 (this->*RE.Routine)(Opcodes, OCI);
313 Decoded = true;
314 break;
315 }
316 }
317 if (!Decoded)
318 SW.startLine() << format("0x%02X ; reserved\n", Opcodes[OCI++ ^ 3]);
319 }
320 }
321
322 template <typename ET>
323 class PrinterContext {
324 typedef typename ET::Sym Elf_Sym;
325 typedef typename ET::Shdr Elf_Shdr;
326 typedef typename ET::Rel Elf_Rel;
327 typedef typename ET::Word Elf_Word;
328
329 ScopedPrinter &SW;
330 const object::ELFFile<ET> &ELF;
331 StringRef FileName;
332 const Elf_Shdr *Symtab;
333 ArrayRef<Elf_Word> ShndxTable;
334
335 static const size_t IndexTableEntrySize;
336
337 static uint64_t PREL31(uint32_t Address, uint32_t Place) {
338 uint64_t Location = Address & 0x7fffffff;
339 if (Location & 0x40000000)
340 Location |= (uint64_t) ~0x7fffffff;
341 return Location + Place;
342 }
343
344 ErrorOr<StringRef>
345 FunctionAtAddress(uint64_t Address,
346 std::optional<unsigned> SectionIndex) const;
347 const Elf_Shdr *FindExceptionTable(unsigned IndexTableIndex,
348 off_t IndexTableOffset) const;
349
350 void PrintIndexTable(unsigned SectionIndex, const Elf_Shdr *IT) const;
351 void PrintExceptionTable(const Elf_Shdr &EHT,
352 uint64_t TableEntryOffset) const;
353 void PrintOpcodes(const uint8_t *Entry, size_t Length, off_t Offset) const;
354
355 public:
356 PrinterContext(ScopedPrinter &SW, const object::ELFFile<ET> &ELF,
357 StringRef FileName, const Elf_Shdr *Symtab)
358 : SW(SW), ELF(ELF), FileName(FileName), Symtab(Symtab) {}
359
360 void PrintUnwindInformation() const;
361 };
362
363 template <typename ET>
364 const size_t PrinterContext<ET>::IndexTableEntrySize = 8;
365
366 template <typename ET>
367 ErrorOr<StringRef> PrinterContext<ET>::FunctionAtAddress(
368 uint64_t Address, std::optional<unsigned> SectionIndex) const {
369 if (!Symtab)
370 return inconvertibleErrorCode();
371 auto StrTableOrErr = ELF.getStringTableForSymtab(*Symtab);
372 if (!StrTableOrErr)
373 reportError(StrTableOrErr.takeError(), FileName);
374 StringRef StrTable = *StrTableOrErr;
375
376 for (const Elf_Sym &Sym : unwrapOrError(FileName, ELF.symbols(Symtab))) {
377 if (SectionIndex && *SectionIndex != Sym.st_shndx)
378 continue;
379
380 if (Sym.st_value == Address && Sym.getType() == ELF::STT_FUNC) {
381 auto NameOrErr = Sym.getName(StrTable);
382 if (!NameOrErr) {
383 // TODO: Actually report errors helpfully.
384 consumeError(NameOrErr.takeError());
385 return inconvertibleErrorCode();
386 }
387 return *NameOrErr;
388 }
389 }
390
391 return inconvertibleErrorCode();
392 }
393
394 template <typename ET>
395 const typename ET::Shdr *
396 PrinterContext<ET>::FindExceptionTable(unsigned IndexSectionIndex,
397 off_t IndexTableOffset) const {
398 /// Iterate through the sections, searching for the relocation section
399 /// associated with the unwind index table section specified by
400 /// IndexSectionIndex. Iterate the associated section searching for the
401 /// relocation associated with the index table entry specified by
402 /// IndexTableOffset. The symbol is the section symbol for the exception
403 /// handling table. Use this symbol to recover the actual exception handling
404 /// table.
405
406 for (const Elf_Shdr &Sec : unwrapOrError(FileName, ELF.sections())) {
407 if (Sec.sh_type != ELF::SHT_REL || Sec.sh_info != IndexSectionIndex)
408 continue;
409
410 auto SymTabOrErr = ELF.getSection(Sec.sh_link);
411 if (!SymTabOrErr)
412 reportError(SymTabOrErr.takeError(), FileName);
413 const Elf_Shdr *SymTab = *SymTabOrErr;
414
415 for (const Elf_Rel &R : unwrapOrError(FileName, ELF.rels(Sec))) {
416 if (R.r_offset != static_cast<unsigned>(IndexTableOffset))
417 continue;
418
419 typename ET::Rela RelA;
420 RelA.r_offset = R.r_offset;
421 RelA.r_info = R.r_info;
422 RelA.r_addend = 0;
423
424 const Elf_Sym *Symbol =
425 unwrapOrError(FileName, ELF.getRelocationSymbol(RelA, SymTab));
426
427 auto Ret = ELF.getSection(*Symbol, SymTab, ShndxTable);
428 if (!Ret)
429 report_fatal_error(Twine(errorToErrorCode(Ret.takeError()).message()));
430 return *Ret;
431 }
432 }
433 return nullptr;
434 }
435
436 template <typename ET>
437 static const typename ET::Shdr *
438 findSectionContainingAddress(const object::ELFFile<ET> &Obj, StringRef FileName,
439 uint64_t Address) {
440 for (const typename ET::Shdr &Sec : unwrapOrError(FileName, Obj.sections()))
441 if (Address >= Sec.sh_addr && Address < Sec.sh_addr + Sec.sh_size)
442 return &Sec;
443 return nullptr;
444 }
445
446 template <typename ET>
447 void PrinterContext<ET>::PrintExceptionTable(const Elf_Shdr &EHT,
448 uint64_t TableEntryOffset) const {
449 // TODO: handle failure.
450 Expected<ArrayRef<uint8_t>> Contents = ELF.getSectionContents(EHT);
451 if (!Contents)
452 return;
453
454 /// ARM EHABI Section 6.2 - The generic model
455 ///
456 /// An exception-handling table entry for the generic model is laid out as:
457 ///
458 /// 3 3
459 /// 1 0 0
460 /// +-+------------------------------+
461 /// |0| personality routine offset |
462 /// +-+------------------------------+
463 /// | personality routine data ... |
464 ///
465 ///
466 /// ARM EHABI Section 6.3 - The ARM-defined compact model
467 ///
468 /// An exception-handling table entry for the compact model looks like:
469 ///
470 /// 3 3 2 2 2 2
471 /// 1 0 8 7 4 3 0
472 /// +-+---+----+-----------------------+
473 /// |1| 0 | Ix | data for pers routine |
474 /// +-+---+----+-----------------------+
475 /// | more personality routine data |
476
477 const support::ulittle32_t Word =
478 *reinterpret_cast<const support::ulittle32_t *>(Contents->data() + TableEntryOffset);
479
480 if (Word & 0x80000000) {
481 SW.printString("Model", StringRef("Compact"));
482
483 unsigned PersonalityIndex = (Word & 0x0f000000) >> 24;
484 SW.printNumber("PersonalityIndex", PersonalityIndex);
485
486 switch (PersonalityIndex) {
487 case AEABI_UNWIND_CPP_PR0:
488 PrintOpcodes(Contents->data() + TableEntryOffset, 3, 1);
489 break;
490 case AEABI_UNWIND_CPP_PR1:
491 case AEABI_UNWIND_CPP_PR2:
492 unsigned AdditionalWords = (Word & 0x00ff0000) >> 16;
493 PrintOpcodes(Contents->data() + TableEntryOffset, 2 + 4 * AdditionalWords,
494 2);
495 break;
496 }
497 } else {
498 SW.printString("Model", StringRef("Generic"));
499 const bool IsRelocatable = ELF.getHeader().e_type == ELF::ET_REL;
500 uint64_t Address = IsRelocatable
501 ? PREL31(Word, EHT.sh_addr)
502 : PREL31(Word, EHT.sh_addr + TableEntryOffset);
503 SW.printHex("PersonalityRoutineAddress", Address);
504 std::optional<unsigned> SecIndex =
505 IsRelocatable ? std::optional<unsigned>(EHT.sh_link) : std::nullopt;
506 if (ErrorOr<StringRef> Name = FunctionAtAddress(Address, SecIndex))
507 SW.printString("PersonalityRoutineName", *Name);
508 }
509 }
510
511 template <typename ET>
512 void PrinterContext<ET>::PrintOpcodes(const uint8_t *Entry,
513 size_t Length, off_t Offset) const {
514 ListScope OCC(SW, "Opcodes");
515 OpcodeDecoder(SW).Decode(Entry, Offset, Length);
516 }
517
518 template <typename ET>
519 void PrinterContext<ET>::PrintIndexTable(unsigned SectionIndex,
520 const Elf_Shdr *IT) const {
521 // TODO: handle failure.
522 Expected<ArrayRef<uint8_t>> Contents = ELF.getSectionContents(*IT);
523 if (!Contents)
524 return;
525
526 /// ARM EHABI Section 5 - Index Table Entries
527 /// * The first word contains a PREL31 offset to the start of a function with
528 /// bit 31 clear
529 /// * The second word contains one of:
530 /// - The PREL31 offset of the start of the table entry for the function,
531 /// with bit 31 clear
532 /// - The exception-handling table entry itself with bit 31 set
533 /// - The special bit pattern EXIDX_CANTUNWIND, indicating that associated
534 /// frames cannot be unwound
535
536 const support::ulittle32_t *Data =
537 reinterpret_cast<const support::ulittle32_t *>(Contents->data());
538 const unsigned Entries = IT->sh_size / IndexTableEntrySize;
539 const bool IsRelocatable = ELF.getHeader().e_type == ELF::ET_REL;
540
541 ListScope E(SW, "Entries");
542 for (unsigned Entry = 0; Entry < Entries; ++Entry) {
543 DictScope E(SW, "Entry");
544
545 const support::ulittle32_t Word0 =
546 Data[Entry * (IndexTableEntrySize / sizeof(*Data)) + 0];
547 const support::ulittle32_t Word1 =
548 Data[Entry * (IndexTableEntrySize / sizeof(*Data)) + 1];
549
550 if (Word0 & 0x80000000) {
551 errs() << "corrupt unwind data in section " << SectionIndex << "\n";
552 continue;
553 }
554
555 // FIXME: For a relocatable object ideally we might want to:
556 // 1) Find a relocation for the offset of Word0.
557 // 2) Verify this relocation is of an expected type (R_ARM_PREL31) and
558 // verify the symbol index.
559 // 3) Resolve the relocation using it's symbol value, addend etc.
560 // Currently the code assumes that Word0 contains an addend of a
561 // R_ARM_PREL31 REL relocation that references a section symbol. RELA
562 // relocations are not supported and it works because addresses of sections
563 // are nulls in relocatable objects.
564 //
565 // For a non-relocatable object, Word0 contains a place-relative signed
566 // offset to the referenced entity.
567 const uint64_t Address =
568 IsRelocatable
569 ? PREL31(Word0, IT->sh_addr)
570 : PREL31(Word0, IT->sh_addr + Entry * IndexTableEntrySize);
571 SW.printHex("FunctionAddress", Address);
572
573 // In a relocatable output we might have many .ARM.exidx sections linked to
574 // their code sections via the sh_link field. For a non-relocatable ELF file
575 // the sh_link field is not reliable, because we have one .ARM.exidx section
576 // normally, but might have many code sections.
577 std::optional<unsigned> SecIndex =
578 IsRelocatable ? std::optional<unsigned>(IT->sh_link) : std::nullopt;
579 if (ErrorOr<StringRef> Name = FunctionAtAddress(Address, SecIndex))
580 SW.printString("FunctionName", *Name);
581
582 if (Word1 == EXIDX_CANTUNWIND) {
583 SW.printString("Model", StringRef("CantUnwind"));
584 continue;
585 }
586
587 if (Word1 & 0x80000000) {
588 SW.printString("Model", StringRef("Compact (Inline)"));
589
590 unsigned PersonalityIndex = (Word1 & 0x0f000000) >> 24;
591 SW.printNumber("PersonalityIndex", PersonalityIndex);
592
593 PrintOpcodes(Contents->data() + Entry * IndexTableEntrySize + 4, 3, 1);
594 } else {
595 const Elf_Shdr *EHT;
596 uint64_t TableEntryAddress;
597 if (IsRelocatable) {
598 TableEntryAddress = PREL31(Word1, IT->sh_addr);
599 EHT = FindExceptionTable(SectionIndex, Entry * IndexTableEntrySize + 4);
600 } else {
601 TableEntryAddress =
602 PREL31(Word1, IT->sh_addr + Entry * IndexTableEntrySize + 4);
603 EHT = findSectionContainingAddress(ELF, FileName, TableEntryAddress);
604 }
605
606 if (EHT)
607 // TODO: handle failure.
608 if (Expected<StringRef> Name = ELF.getSectionName(*EHT))
609 SW.printString("ExceptionHandlingTable", *Name);
610
611 SW.printHex(IsRelocatable ? "TableEntryOffset" : "TableEntryAddress",
612 TableEntryAddress);
613 if (EHT) {
614 if (IsRelocatable)
615 PrintExceptionTable(*EHT, TableEntryAddress);
616 else
617 PrintExceptionTable(*EHT, TableEntryAddress - EHT->sh_addr);
618 }
619 }
620 }
621 }
622
623 template <typename ET>
624 void PrinterContext<ET>::PrintUnwindInformation() const {
625 DictScope UI(SW, "UnwindInformation");
626
627 int SectionIndex = 0;
628 for (const Elf_Shdr &Sec : unwrapOrError(FileName, ELF.sections())) {
629 if (Sec.sh_type == ELF::SHT_ARM_EXIDX) {
630 DictScope UIT(SW, "UnwindIndexTable");
631
632 SW.printNumber("SectionIndex", SectionIndex);
633 // TODO: handle failure.
634 if (Expected<StringRef> SectionName = ELF.getSectionName(Sec))
635 SW.printString("SectionName", *SectionName);
636 SW.printHex("SectionOffset", Sec.sh_offset);
637
638 PrintIndexTable(SectionIndex, &Sec);
639 }
640 ++SectionIndex;
641 }
642 }
643 }
644 }
645 }
646
647 #endif
LLVM monorepo