1 //===--- ARMEHABIPrinter.h - ARM EHABI Unwind Information Printer ----------===//
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 #ifndef LLVM_READOBJ_ARMEHABI_PRINTER_H
11 #define LLVM_READOBJ_ARMEHABI_PRINTER_H
12
13 #include "Error.h"
14 #include "StreamWriter.h"
15 #include "llvm/ADT/STLExtras.h"
16 #include "llvm/Object/ELF.h"
17 #include "llvm/Object/ELFTypes.h"
18 #include "llvm/Support/ARMEHABI.h"
19 #include "llvm/Support/Debug.h"
20 #include "llvm/Support/Endian.h"
21 #include "llvm/Support/Format.h"
22 #include "llvm/Support/type_traits.h"
23
24 namespace llvm {
25 namespace ARM {
26 namespace EHABI {
27
28 class OpcodeDecoder {
29 StreamWriter &SW;
30 raw_ostream &OS;
31
32 struct RingEntry {
33 uint8_t Mask;
34 uint8_t Value;
35 void (OpcodeDecoder::*Routine)(const uint8_t *Opcodes, unsigned &OI);
36 };
37 static const RingEntry Ring[];
38
39 void Decode_00xxxxxx(const uint8_t *Opcodes, unsigned &OI);
40 void Decode_01xxxxxx(const uint8_t *Opcodes, unsigned &OI);
41 void Decode_1000iiii_iiiiiiii(const uint8_t *Opcodes, unsigned &OI);
42 void Decode_10011101(const uint8_t *Opcodes, unsigned &OI);
43 void Decode_10011111(const uint8_t *Opcodes, unsigned &OI);
44 void Decode_1001nnnn(const uint8_t *Opcodes, unsigned &OI);
45 void Decode_10100nnn(const uint8_t *Opcodes, unsigned &OI);
46 void Decode_10101nnn(const uint8_t *Opcodes, unsigned &OI);
47 void Decode_10110000(const uint8_t *Opcodes, unsigned &OI);
48 void Decode_10110001_0000iiii(const uint8_t *Opcodes, unsigned &OI);
49 void Decode_10110010_uleb128(const uint8_t *Opcodes, unsigned &OI);
50 void Decode_10110011_sssscccc(const uint8_t *Opcodes, unsigned &OI);
51 void Decode_101101nn(const uint8_t *Opcodes, unsigned &OI);
52 void Decode_10111nnn(const uint8_t *Opcodes, unsigned &OI);
53 void Decode_11000110_sssscccc(const uint8_t *Opcodes, unsigned &OI);
54 void Decode_11000111_0000iiii(const uint8_t *Opcodes, unsigned &OI);
55 void Decode_11001000_sssscccc(const uint8_t *Opcodes, unsigned &OI);
56 void Decode_11001001_sssscccc(const uint8_t *Opcodes, unsigned &OI);
57 void Decode_11001yyy(const uint8_t *Opcodes, unsigned &OI);
58 void Decode_11000nnn(const uint8_t *Opcodes, unsigned &OI);
59 void Decode_11010nnn(const uint8_t *Opcodes, unsigned &OI);
60 void Decode_11xxxyyy(const uint8_t *Opcodes, unsigned &OI);
61
62 void PrintGPR(uint16_t GPRMask);
63 void PrintRegisters(uint32_t Mask, StringRef Prefix);
64
65 public:
OpcodeDecoder(StreamWriter & SW)66 OpcodeDecoder(StreamWriter &SW) : SW(SW), OS(SW.getOStream()) {}
67 void Decode(const uint8_t *Opcodes, off_t Offset, size_t Length);
68 };
69
70 const OpcodeDecoder::RingEntry OpcodeDecoder::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
Decode_00xxxxxx(const uint8_t * Opcodes,unsigned & OI)95 void OpcodeDecoder::Decode_00xxxxxx(const uint8_t *Opcodes, unsigned &OI) {
96 uint8_t Opcode = Opcodes[OI++ ^ 3];
97 SW.startLine() << format("0x%02X ; vsp = vsp + %u\n", Opcode,
98 ((Opcode & 0x3f) << 2) + 4);
99 }
Decode_01xxxxxx(const uint8_t * Opcodes,unsigned & OI)100 void OpcodeDecoder::Decode_01xxxxxx(const uint8_t *Opcodes, unsigned &OI) {
101 uint8_t Opcode = Opcodes[OI++ ^ 3];
102 SW.startLine() << format("0x%02X ; vsp = vsp - %u\n", Opcode,
103 ((Opcode & 0x3f) << 2) + 4);
104 }
Decode_1000iiii_iiiiiiii(const uint8_t * Opcodes,unsigned & OI)105 void OpcodeDecoder::Decode_1000iiii_iiiiiiii(const uint8_t *Opcodes,
106 unsigned &OI) {
107 uint8_t Opcode0 = Opcodes[OI++ ^ 3];
108 uint8_t Opcode1 = Opcodes[OI++ ^ 3];
109
110 uint16_t GPRMask = (Opcode1 << 4) | ((Opcode0 & 0x0f) << 12);
111 SW.startLine()
112 << format("0x%02X 0x%02X ; %s",
113 Opcode0, Opcode1, GPRMask ? "pop " : "refuse to unwind");
114 if (GPRMask)
115 PrintGPR(GPRMask);
116 OS << '\n';
117 }
Decode_10011101(const uint8_t * Opcodes,unsigned & OI)118 void OpcodeDecoder::Decode_10011101(const uint8_t *Opcodes, unsigned &OI) {
119 uint8_t Opcode = Opcodes[OI++ ^ 3];
120 SW.startLine() << format("0x%02X ; reserved (ARM MOVrr)\n", Opcode);
121 }
Decode_10011111(const uint8_t * Opcodes,unsigned & OI)122 void OpcodeDecoder::Decode_10011111(const uint8_t *Opcodes, unsigned &OI) {
123 uint8_t Opcode = Opcodes[OI++ ^ 3];
124 SW.startLine() << format("0x%02X ; reserved (WiMMX MOVrr)\n", Opcode);
125 }
Decode_1001nnnn(const uint8_t * Opcodes,unsigned & OI)126 void OpcodeDecoder::Decode_1001nnnn(const uint8_t *Opcodes, unsigned &OI) {
127 uint8_t Opcode = Opcodes[OI++ ^ 3];
128 SW.startLine() << format("0x%02X ; vsp = r%u\n", Opcode, (Opcode & 0x0f));
129 }
Decode_10100nnn(const uint8_t * Opcodes,unsigned & OI)130 void OpcodeDecoder::Decode_10100nnn(const uint8_t *Opcodes, unsigned &OI) {
131 uint8_t Opcode = Opcodes[OI++ ^ 3];
132 SW.startLine() << format("0x%02X ; pop ", Opcode);
133 PrintGPR((((1 << ((Opcode & 0x7) + 1)) - 1) << 4));
134 OS << '\n';
135 }
Decode_10101nnn(const uint8_t * Opcodes,unsigned & OI)136 void OpcodeDecoder::Decode_10101nnn(const uint8_t *Opcodes, unsigned &OI) {
137 uint8_t Opcode = Opcodes[OI++ ^ 3];
138 SW.startLine() << format("0x%02X ; pop ", Opcode);
139 PrintGPR((((1 << ((Opcode & 0x7) + 1)) - 1) << 4) | (1 << 14));
140 OS << '\n';
141 }
Decode_10110000(const uint8_t * Opcodes,unsigned & OI)142 void OpcodeDecoder::Decode_10110000(const uint8_t *Opcodes, unsigned &OI) {
143 uint8_t Opcode = Opcodes[OI++ ^ 3];
144 SW.startLine() << format("0x%02X ; finish\n", Opcode);
145 }
Decode_10110001_0000iiii(const uint8_t * Opcodes,unsigned & OI)146 void OpcodeDecoder::Decode_10110001_0000iiii(const uint8_t *Opcodes,
147 unsigned &OI) {
148 uint8_t Opcode0 = Opcodes[OI++ ^ 3];
149 uint8_t Opcode1 = Opcodes[OI++ ^ 3];
150
151 SW.startLine()
152 << format("0x%02X 0x%02X ; %s", Opcode0, Opcode1,
153 ((Opcode1 & 0xf0) || Opcode1 == 0x00) ? "spare" : "pop ");
154 if (((Opcode1 & 0xf0) == 0x00) && Opcode1)
155 PrintGPR((Opcode1 & 0x0f));
156 OS << '\n';
157 }
Decode_10110010_uleb128(const uint8_t * Opcodes,unsigned & OI)158 void OpcodeDecoder::Decode_10110010_uleb128(const uint8_t *Opcodes,
159 unsigned &OI) {
160 uint8_t Opcode = Opcodes[OI++ ^ 3];
161 SW.startLine() << format("0x%02X ", Opcode);
162
163 SmallVector<uint8_t, 4> ULEB;
164 do { ULEB.push_back(Opcodes[OI ^ 3]); } while (Opcodes[OI++ ^ 3] & 0x80);
165
166 for (unsigned BI = 0, BE = ULEB.size(); BI != BE; ++BI)
167 OS << format("0x%02X ", ULEB[BI]);
168
169 uint64_t Value = 0;
170 for (unsigned BI = 0, BE = ULEB.size(); BI != BE; ++BI)
171 Value = Value | ((ULEB[BI] & 0x7f) << (7 * BI));
172
173 OS << format("; vsp = vsp + %" PRIu64 "\n", 0x204 + (Value << 2));
174 }
Decode_10110011_sssscccc(const uint8_t * Opcodes,unsigned & OI)175 void OpcodeDecoder::Decode_10110011_sssscccc(const uint8_t *Opcodes,
176 unsigned &OI) {
177 uint8_t Opcode0 = Opcodes[OI++ ^ 3];
178 uint8_t Opcode1 = Opcodes[OI++ ^ 3];
179 SW.startLine() << format("0x%02X 0x%02X ; pop ", Opcode0, Opcode1);
180 uint8_t Start = ((Opcode1 & 0xf0) >> 4);
181 uint8_t Count = ((Opcode1 & 0x0f) >> 0);
182 PrintRegisters((((1 << (Count + 1)) - 1) << Start), "d");
183 OS << '\n';
184 }
Decode_101101nn(const uint8_t * Opcodes,unsigned & OI)185 void OpcodeDecoder::Decode_101101nn(const uint8_t *Opcodes, unsigned &OI) {
186 uint8_t Opcode = Opcodes[OI++ ^ 3];
187 SW.startLine() << format("0x%02X ; spare\n", Opcode);
188 }
Decode_10111nnn(const uint8_t * Opcodes,unsigned & OI)189 void OpcodeDecoder::Decode_10111nnn(const uint8_t *Opcodes, unsigned &OI) {
190 uint8_t Opcode = Opcodes[OI++ ^ 3];
191 SW.startLine() << format("0x%02X ; pop ", Opcode);
192 PrintRegisters((((1 << ((Opcode & 0x07) + 1)) - 1) << 8), "d");
193 OS << '\n';
194 }
Decode_11000110_sssscccc(const uint8_t * Opcodes,unsigned & OI)195 void OpcodeDecoder::Decode_11000110_sssscccc(const uint8_t *Opcodes,
196 unsigned &OI) {
197 uint8_t Opcode0 = Opcodes[OI++ ^ 3];
198 uint8_t Opcode1 = Opcodes[OI++ ^ 3];
199 SW.startLine() << format("0x%02X 0x%02X ; pop ", Opcode0, Opcode1);
200 uint8_t Start = ((Opcode1 & 0xf0) >> 4);
201 uint8_t Count = ((Opcode1 & 0x0f) >> 0);
202 PrintRegisters((((1 << (Count + 1)) - 1) << Start), "wR");
203 OS << '\n';
204 }
Decode_11000111_0000iiii(const uint8_t * Opcodes,unsigned & OI)205 void OpcodeDecoder::Decode_11000111_0000iiii(const uint8_t *Opcodes,
206 unsigned &OI) {
207 uint8_t Opcode0 = Opcodes[OI++ ^ 3];
208 uint8_t Opcode1 = Opcodes[OI++ ^ 3];
209 SW.startLine()
210 << format("0x%02X 0x%02X ; %s", Opcode0, Opcode1,
211 ((Opcode1 & 0xf0) || Opcode1 == 0x00) ? "spare" : "pop ");
212 if ((Opcode1 & 0xf0) == 0x00 && Opcode1)
213 PrintRegisters(Opcode1 & 0x0f, "wCGR");
214 OS << '\n';
215 }
Decode_11001000_sssscccc(const uint8_t * Opcodes,unsigned & OI)216 void OpcodeDecoder::Decode_11001000_sssscccc(const uint8_t *Opcodes,
217 unsigned &OI) {
218 uint8_t Opcode0 = Opcodes[OI++ ^ 3];
219 uint8_t Opcode1 = Opcodes[OI++ ^ 3];
220 SW.startLine() << format("0x%02X 0x%02X ; pop ", Opcode0, Opcode1);
221 uint8_t Start = 16 + ((Opcode1 & 0xf0) >> 4);
222 uint8_t Count = ((Opcode1 & 0x0f) >> 0);
223 PrintRegisters((((1 << (Count + 1)) - 1) << Start), "d");
224 OS << '\n';
225 }
Decode_11001001_sssscccc(const uint8_t * Opcodes,unsigned & OI)226 void OpcodeDecoder::Decode_11001001_sssscccc(const uint8_t *Opcodes,
227 unsigned &OI) {
228 uint8_t Opcode0 = Opcodes[OI++ ^ 3];
229 uint8_t Opcode1 = Opcodes[OI++ ^ 3];
230 SW.startLine() << format("0x%02X 0x%02X ; pop ", Opcode0, Opcode1);
231 uint8_t Start = ((Opcode1 & 0xf0) >> 4);
232 uint8_t Count = ((Opcode1 & 0x0f) >> 0);
233 PrintRegisters((((1 << (Count + 1)) - 1) << Start), "d");
234 OS << '\n';
235 }
Decode_11001yyy(const uint8_t * Opcodes,unsigned & OI)236 void OpcodeDecoder::Decode_11001yyy(const uint8_t *Opcodes, unsigned &OI) {
237 uint8_t Opcode = Opcodes[OI++ ^ 3];
238 SW.startLine() << format("0x%02X ; spare\n", Opcode);
239 }
Decode_11000nnn(const uint8_t * Opcodes,unsigned & OI)240 void OpcodeDecoder::Decode_11000nnn(const uint8_t *Opcodes, unsigned &OI) {
241 uint8_t Opcode = Opcodes[OI++ ^ 3];
242 SW.startLine() << format("0x%02X ; pop ", Opcode);
243 PrintRegisters((((1 << ((Opcode & 0x07) + 1)) - 1) << 10), "wR");
244 OS << '\n';
245 }
Decode_11010nnn(const uint8_t * Opcodes,unsigned & OI)246 void OpcodeDecoder::Decode_11010nnn(const uint8_t *Opcodes, unsigned &OI) {
247 uint8_t Opcode = Opcodes[OI++ ^ 3];
248 SW.startLine() << format("0x%02X ; pop ", Opcode);
249 PrintRegisters((((1 << ((Opcode & 0x07) + 1)) - 1) << 8), "d");
250 OS << '\n';
251 }
Decode_11xxxyyy(const uint8_t * Opcodes,unsigned & OI)252 void OpcodeDecoder::Decode_11xxxyyy(const uint8_t *Opcodes, unsigned &OI) {
253 uint8_t Opcode = Opcodes[OI++ ^ 3];
254 SW.startLine() << format("0x%02X ; spare\n", Opcode);
255 }
256
PrintGPR(uint16_t GPRMask)257 void OpcodeDecoder::PrintGPR(uint16_t GPRMask) {
258 static const char *GPRRegisterNames[16] = {
259 "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", "r8", "r9", "r10",
260 "fp", "ip", "sp", "lr", "pc"
261 };
262
263 OS << '{';
264 bool Comma = false;
265 for (unsigned RI = 0, RE = 17; RI < RE; ++RI) {
266 if (GPRMask & (1 << RI)) {
267 if (Comma)
268 OS << ", ";
269 OS << GPRRegisterNames[RI];
270 Comma = true;
271 }
272 }
273 OS << '}';
274 }
275
PrintRegisters(uint32_t VFPMask,StringRef Prefix)276 void OpcodeDecoder::PrintRegisters(uint32_t VFPMask, StringRef Prefix) {
277 OS << '{';
278 bool Comma = false;
279 for (unsigned RI = 0, RE = 32; RI < RE; ++RI) {
280 if (VFPMask & (1 << RI)) {
281 if (Comma)
282 OS << ", ";
283 OS << Prefix << RI;
284 Comma = true;
285 }
286 }
287 OS << '}';
288 }
289
Decode(const uint8_t * Opcodes,off_t Offset,size_t Length)290 void OpcodeDecoder::Decode(const uint8_t *Opcodes, off_t Offset, size_t Length) {
291 for (unsigned OCI = Offset; OCI < Length + Offset; ) {
292 bool Decoded = false;
293 for (unsigned REI = 0, REE = array_lengthof(Ring);
294 REI != REE && !Decoded; ++REI) {
295 if ((Opcodes[OCI ^ 3] & Ring[REI].Mask) == Ring[REI].Value) {
296 (this->*Ring[REI].Routine)(Opcodes, OCI);
297 Decoded = true;
298 break;
299 }
300 }
301 if (!Decoded)
302 SW.startLine() << format("0x%02X ; reserved\n", Opcodes[OCI++ ^ 3]);
303 }
304 }
305
306 template <typename ET>
307 class PrinterContext {
308 StreamWriter &SW;
309 const object::ELFFile<ET> *ELF;
310
311 typedef typename object::ELFFile<ET>::Elf_Sym Elf_Sym;
312 typedef typename object::ELFFile<ET>::Elf_Shdr Elf_Shdr;
313
314 typedef typename object::ELFFile<ET>::Elf_Rel_Iter Elf_Rel_iterator;
315 typedef typename object::ELFFile<ET>::Elf_Sym_Iter Elf_Sym_iterator;
316 typedef typename object::ELFFile<ET>::Elf_Shdr_Iter Elf_Shdr_iterator;
317
318 static const size_t IndexTableEntrySize;
319
PREL31(uint32_t Address,uint32_t Place)320 static uint64_t PREL31(uint32_t Address, uint32_t Place) {
321 uint64_t Location = Address & 0x7fffffff;
322 if (Location & 0x04000000)
323 Location |= (uint64_t) ~0x7fffffff;
324 return Location + Place;
325 }
326
327 ErrorOr<StringRef> FunctionAtAddress(unsigned Section, uint64_t Address) const;
328 const Elf_Shdr *FindExceptionTable(unsigned IndexTableIndex,
329 off_t IndexTableOffset) const;
330
331 void PrintIndexTable(unsigned SectionIndex, const Elf_Shdr *IT) const;
332 void PrintExceptionTable(const Elf_Shdr *IT, const Elf_Shdr *EHT,
333 uint64_t TableEntryOffset) const;
334 void PrintOpcodes(const uint8_t *Entry, size_t Length, off_t Offset) const;
335
336 public:
PrinterContext(StreamWriter & Writer,const object::ELFFile<ET> * File)337 PrinterContext(StreamWriter &Writer, const object::ELFFile<ET> *File)
338 : SW(Writer), ELF(File) {}
339
340 void PrintUnwindInformation() const;
341 };
342
343 template <typename ET>
344 const size_t PrinterContext<ET>::IndexTableEntrySize = 8;
345
346 template <typename ET>
FunctionAtAddress(unsigned Section,uint64_t Address)347 ErrorOr<StringRef> PrinterContext<ET>::FunctionAtAddress(unsigned Section,
348 uint64_t Address) const {
349 for (Elf_Sym_iterator SI = ELF->begin_symbols(), SE = ELF->end_symbols();
350 SI != SE; ++SI)
351 if (SI->st_shndx == Section && SI->st_value == Address &&
352 SI->getType() == ELF::STT_FUNC)
353 return ELF->getSymbolName(SI);
354 return readobj_error::unknown_symbol;
355 }
356
357 template <typename ET>
358 const typename object::ELFFile<ET>::Elf_Shdr *
FindExceptionTable(unsigned IndexSectionIndex,off_t IndexTableOffset)359 PrinterContext<ET>::FindExceptionTable(unsigned IndexSectionIndex,
360 off_t IndexTableOffset) const {
361 /// Iterate through the sections, searching for the relocation section
362 /// associated with the unwind index table section specified by
363 /// IndexSectionIndex. Iterate the associated section searching for the
364 /// relocation associated with the index table entry specified by
365 /// IndexTableOffset. The symbol is the section symbol for the exception
366 /// handling table. Use this symbol to recover the actual exception handling
367 /// table.
368
369 for (Elf_Shdr_iterator SI = ELF->begin_sections(), SE = ELF->end_sections();
370 SI != SE; ++SI) {
371 if (SI->sh_type == ELF::SHT_REL && SI->sh_info == IndexSectionIndex) {
372 for (Elf_Rel_iterator RI = ELF->begin_rel(&*SI), RE = ELF->end_rel(&*SI);
373 RI != RE; ++RI) {
374 if (RI->r_offset == static_cast<unsigned>(IndexTableOffset)) {
375 typename object::ELFFile<ET>::Elf_Rela RelA;
376 RelA.r_offset = RI->r_offset;
377 RelA.r_info = RI->r_info;
378 RelA.r_addend = 0;
379
380 std::pair<const Elf_Shdr *, const Elf_Sym *> Symbol =
381 ELF->getRelocationSymbol(&(*SI), &RelA);
382
383 return ELF->getSection(Symbol.second);
384 }
385 }
386 }
387 }
388 return nullptr;
389 }
390
391 template <typename ET>
PrintExceptionTable(const Elf_Shdr * IT,const Elf_Shdr * EHT,uint64_t TableEntryOffset)392 void PrinterContext<ET>::PrintExceptionTable(const Elf_Shdr *IT,
393 const Elf_Shdr *EHT,
394 uint64_t TableEntryOffset) const {
395 ErrorOr<ArrayRef<uint8_t> > Contents = ELF->getSectionContents(EHT);
396 if (!Contents)
397 return;
398
399 /// ARM EHABI Section 6.2 - The generic model
400 ///
401 /// An exception-handling table entry for the generic model is laid out as:
402 ///
403 /// 3 3
404 /// 1 0 0
405 /// +-+------------------------------+
406 /// |0| personality routine offset |
407 /// +-+------------------------------+
408 /// | personality routine data ... |
409 ///
410 ///
411 /// ARM EHABI Section 6.3 - The ARM-defined compact model
412 ///
413 /// An exception-handling table entry for the compact model looks like:
414 ///
415 /// 3 3 2 2 2 2
416 /// 1 0 8 7 4 3 0
417 /// +-+---+----+-----------------------+
418 /// |1| 0 | Ix | data for pers routine |
419 /// +-+---+----+-----------------------+
420 /// | more personality routine data |
421
422 const support::ulittle32_t Word =
423 *reinterpret_cast<const support::ulittle32_t *>(Contents->data() + TableEntryOffset);
424
425 if (Word & 0x80000000) {
426 SW.printString("Model", StringRef("Compact"));
427
428 unsigned PersonalityIndex = (Word & 0x0f000000) >> 24;
429 SW.printNumber("PersonalityIndex", PersonalityIndex);
430
431 switch (PersonalityIndex) {
432 case AEABI_UNWIND_CPP_PR0:
433 PrintOpcodes(Contents->data() + TableEntryOffset, 3, 1);
434 break;
435 case AEABI_UNWIND_CPP_PR1:
436 case AEABI_UNWIND_CPP_PR2:
437 unsigned AdditionalWords = (Word & 0x00ff0000) >> 16;
438 PrintOpcodes(Contents->data() + TableEntryOffset, 2 + 4 * AdditionalWords,
439 2);
440 break;
441 }
442 } else {
443 SW.printString("Model", StringRef("Generic"));
444
445 uint64_t Address = PREL31(Word, EHT->sh_addr);
446 SW.printHex("PersonalityRoutineAddress", Address);
447 if (ErrorOr<StringRef> Name = FunctionAtAddress(EHT->sh_link, Address))
448 SW.printString("PersonalityRoutineName", *Name);
449 }
450 }
451
452 template <typename ET>
PrintOpcodes(const uint8_t * Entry,size_t Length,off_t Offset)453 void PrinterContext<ET>::PrintOpcodes(const uint8_t *Entry,
454 size_t Length, off_t Offset) const {
455 ListScope OCC(SW, "Opcodes");
456 OpcodeDecoder(OCC.W).Decode(Entry, Offset, Length);
457 }
458
459 template <typename ET>
PrintIndexTable(unsigned SectionIndex,const Elf_Shdr * IT)460 void PrinterContext<ET>::PrintIndexTable(unsigned SectionIndex,
461 const Elf_Shdr *IT) const {
462 ErrorOr<ArrayRef<uint8_t> > Contents = ELF->getSectionContents(IT);
463 if (!Contents)
464 return;
465
466 /// ARM EHABI Section 5 - Index Table Entries
467 /// * The first word contains a PREL31 offset to the start of a function with
468 /// bit 31 clear
469 /// * The second word contains one of:
470 /// - The PREL31 offset of the start of the table entry for the function,
471 /// with bit 31 clear
472 /// - The exception-handling table entry itself with bit 31 set
473 /// - The special bit pattern EXIDX_CANTUNWIND, indicating that associated
474 /// frames cannot be unwound
475
476 const support::ulittle32_t *Data =
477 reinterpret_cast<const support::ulittle32_t *>(Contents->data());
478 const unsigned Entries = IT->sh_size / IndexTableEntrySize;
479
480 ListScope E(SW, "Entries");
481 for (unsigned Entry = 0; Entry < Entries; ++Entry) {
482 DictScope E(SW, "Entry");
483
484 const support::ulittle32_t Word0 =
485 Data[Entry * (IndexTableEntrySize / sizeof(*Data)) + 0];
486 const support::ulittle32_t Word1 =
487 Data[Entry * (IndexTableEntrySize / sizeof(*Data)) + 1];
488
489 if (Word0 & 0x80000000) {
490 errs() << "corrupt unwind data in section " << SectionIndex << "\n";
491 continue;
492 }
493
494 const uint64_t Offset = PREL31(Word0, IT->sh_addr);
495 SW.printHex("FunctionAddress", Offset);
496 if (ErrorOr<StringRef> Name = FunctionAtAddress(IT->sh_link, Offset))
497 SW.printString("FunctionName", *Name);
498
499 if (Word1 == EXIDX_CANTUNWIND) {
500 SW.printString("Model", StringRef("CantUnwind"));
501 continue;
502 }
503
504 if (Word1 & 0x80000000) {
505 SW.printString("Model", StringRef("Compact (Inline)"));
506
507 unsigned PersonalityIndex = (Word1 & 0x0f000000) >> 24;
508 SW.printNumber("PersonalityIndex", PersonalityIndex);
509
510 PrintOpcodes(Contents->data() + Entry * IndexTableEntrySize + 4, 3, 1);
511 } else {
512 const Elf_Shdr *EHT =
513 FindExceptionTable(SectionIndex, Entry * IndexTableEntrySize + 4);
514
515 if (ErrorOr<StringRef> Name = ELF->getSectionName(EHT))
516 SW.printString("ExceptionHandlingTable", *Name);
517
518 uint64_t TableEntryOffset = PREL31(Word1, IT->sh_addr);
519 SW.printHex("TableEntryOffset", TableEntryOffset);
520
521 PrintExceptionTable(IT, EHT, TableEntryOffset);
522 }
523 }
524 }
525
526 template <typename ET>
PrintUnwindInformation()527 void PrinterContext<ET>::PrintUnwindInformation() const {
528 DictScope UI(SW, "UnwindInformation");
529
530 int SectionIndex = 0;
531 for (Elf_Shdr_iterator SI = ELF->begin_sections(), SE = ELF->end_sections();
532 SI != SE; ++SI, ++SectionIndex) {
533 if (SI->sh_type == ELF::SHT_ARM_EXIDX) {
534 const Elf_Shdr *IT = &(*SI);
535
536 DictScope UIT(SW, "UnwindIndexTable");
537
538 SW.printNumber("SectionIndex", SectionIndex);
539 if (ErrorOr<StringRef> SectionName = ELF->getSectionName(IT))
540 SW.printString("SectionName", *SectionName);
541 SW.printHex("SectionOffset", IT->sh_offset);
542
543 PrintIndexTable(SectionIndex, IT);
544 }
545 }
546 }
547 }
548 }
549 }
550
551 #endif
552
553