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1 //===-- ARMWinEHPrinter.cpp - Windows on ARM EH Data Printer ----*- 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 // Windows on ARM uses a series of serialised data structures (RuntimeFunction)
11 // to create a table of information for unwinding.  In order to conserve space,
12 // there are two different ways that this data is represented.
13 //
14 // For functions with canonical forms for the prologue and epilogue, the data
15 // can be stored in a "packed" form.  In this case, the data is packed into the
16 // RuntimeFunction's remaining 30-bits and can fully describe the entire frame.
17 //
18 //        +---------------------------------------+
19 //        |         Function Entry Address        |
20 //        +---------------------------------------+
21 //        |           Packed Form Data            |
22 //        +---------------------------------------+
23 //
24 // This layout is parsed by Decoder::dumpPackedEntry.  No unwind bytecode is
25 // associated with such a frame as they can be derived from the provided data.
26 // The decoder does not synthesize this data as it is unnecessary for the
27 // purposes of validation, with the synthesis being required only by a proper
28 // unwinder.
29 //
30 // For functions that are large or do not match canonical forms, the data is
31 // split up into two portions, with the actual data residing in the "exception
32 // data" table (.xdata) with a reference to the entry from the "procedure data"
33 // (.pdata) entry.
34 //
35 // The exception data contains information about the frame setup, all of the
36 // epilouge scopes (for functions for which there are multiple exit points) and
37 // the associated exception handler.  Additionally, the entry contains byte-code
38 // describing how to unwind the function (c.f. Decoder::decodeOpcodes).
39 //
40 //        +---------------------------------------+
41 //        |         Function Entry Address        |
42 //        +---------------------------------------+
43 //        |      Exception Data Entry Address     |
44 //        +---------------------------------------+
45 //
46 // This layout is parsed by Decoder::dumpUnpackedEntry.  Such an entry must
47 // first resolve the exception data entry address.  This structure
48 // (ExceptionDataRecord) has a variable sized header
49 // (c.f. ARM::WinEH::HeaderWords) and encodes most of the same information as
50 // the packed form.  However, because this information is insufficient to
51 // synthesize the unwinding, there are associated unwinding bytecode which make
52 // up the bulk of the Decoder.
53 //
54 // The decoder itself is table-driven, using the first byte to determine the
55 // opcode and dispatching to the associated printing routine.  The bytecode
56 // itself is a variable length instruction encoding that can fully describe the
57 // state of the stack and the necessary operations for unwinding to the
58 // beginning of the frame.
59 //
60 // The byte-code maintains a 1-1 instruction mapping, indicating both the width
61 // of the instruction (Thumb2 instructions are variable length, 16 or 32 bits
62 // wide) allowing the program to unwind from any point in the prologue, body, or
63 // epilogue of the function.
64 
65 #include "ARMWinEHPrinter.h"
66 #include "Error.h"
67 #include "llvm/ADT/StringExtras.h"
68 #include "llvm/ADT/STLExtras.h"
69 #include "llvm/Support/ARMWinEH.h"
70 #include "llvm/Support/Format.h"
71 
72 using namespace llvm;
73 using namespace llvm::object;
74 using namespace llvm::support;
75 
76 namespace llvm {
operator <<(raw_ostream & OS,const ARM::WinEH::ReturnType & RT)77 raw_ostream &operator<<(raw_ostream &OS, const ARM::WinEH::ReturnType &RT) {
78   switch (RT) {
79   case ARM::WinEH::ReturnType::RT_POP:
80     OS << "pop {pc}";
81     break;
82   case ARM::WinEH::ReturnType::RT_B:
83     OS << "b target";
84     break;
85   case ARM::WinEH::ReturnType::RT_BW:
86     OS << "b.w target";
87     break;
88   case ARM::WinEH::ReturnType::RT_NoEpilogue:
89     OS << "(no epilogue)";
90     break;
91   }
92   return OS;
93 }
94 }
95 
formatSymbol(StringRef Name,uint64_t Address,uint64_t Offset=0)96 static std::string formatSymbol(StringRef Name, uint64_t Address,
97                                 uint64_t Offset = 0) {
98   std::string Buffer;
99   raw_string_ostream OS(Buffer);
100 
101   if (!Name.empty())
102     OS << Name << " ";
103 
104   if (Offset)
105     OS << format("+0x%X (0x%" PRIX64 ")", Offset, Address);
106   else if (!Name.empty())
107     OS << format("(0x%" PRIX64 ")", Address);
108   else
109     OS << format("0x%" PRIX64, Address);
110 
111   return OS.str();
112 }
113 
114 namespace llvm {
115 namespace ARM {
116 namespace WinEH {
117 const size_t Decoder::PDataEntrySize = sizeof(RuntimeFunction);
118 
119 // TODO name the uops more appropriately
120 const Decoder::RingEntry Decoder::Ring[] = {
121   { 0x80, 0x00, &Decoder::opcode_0xxxxxxx },  // UOP_STACK_FREE (16-bit)
122   { 0xc0, 0x80, &Decoder::opcode_10Lxxxxx },  // UOP_POP (32-bit)
123   { 0xf0, 0xc0, &Decoder::opcode_1100xxxx },  // UOP_STACK_SAVE (16-bit)
124   { 0xf8, 0xd0, &Decoder::opcode_11010Lxx },  // UOP_POP (16-bit)
125   { 0xf8, 0xd8, &Decoder::opcode_11011Lxx },  // UOP_POP (32-bit)
126   { 0xf8, 0xe0, &Decoder::opcode_11100xxx },  // UOP_VPOP (32-bit)
127   { 0xfc, 0xe8, &Decoder::opcode_111010xx },  // UOP_STACK_FREE (32-bit)
128   { 0xfe, 0xec, &Decoder::opcode_1110110L },  // UOP_POP (16-bit)
129   { 0xff, 0xee, &Decoder::opcode_11101110 },  // UOP_MICROSOFT_SPECIFIC (16-bit)
130                                               // UOP_PUSH_MACHINE_FRAME
131                                               // UOP_PUSH_CONTEXT
132                                               // UOP_PUSH_TRAP_FRAME
133                                               // UOP_REDZONE_RESTORE_LR
134   { 0xff, 0xef, &Decoder::opcode_11101111 },  // UOP_LDRPC_POSTINC (32-bit)
135   { 0xff, 0xf5, &Decoder::opcode_11110101 },  // UOP_VPOP (32-bit)
136   { 0xff, 0xf6, &Decoder::opcode_11110110 },  // UOP_VPOP (32-bit)
137   { 0xff, 0xf7, &Decoder::opcode_11110111 },  // UOP_STACK_RESTORE (16-bit)
138   { 0xff, 0xf8, &Decoder::opcode_11111000 },  // UOP_STACK_RESTORE (16-bit)
139   { 0xff, 0xf9, &Decoder::opcode_11111001 },  // UOP_STACK_RESTORE (32-bit)
140   { 0xff, 0xfa, &Decoder::opcode_11111010 },  // UOP_STACK_RESTORE (32-bit)
141   { 0xff, 0xfb, &Decoder::opcode_11111011 },  // UOP_NOP (16-bit)
142   { 0xff, 0xfc, &Decoder::opcode_11111100 },  // UOP_NOP (32-bit)
143   { 0xff, 0xfd, &Decoder::opcode_11111101 },  // UOP_NOP (16-bit) / END
144   { 0xff, 0xfe, &Decoder::opcode_11111110 },  // UOP_NOP (32-bit) / END
145   { 0xff, 0xff, &Decoder::opcode_11111111 },  // UOP_END
146 };
147 
printRegisters(const std::pair<uint16_t,uint32_t> & RegisterMask)148 void Decoder::printRegisters(const std::pair<uint16_t, uint32_t> &RegisterMask) {
149   static const char * const GPRRegisterNames[16] = {
150     "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", "r8", "r9", "r10",
151     "r11", "ip", "sp", "lr", "pc",
152   };
153 
154   const uint16_t GPRMask = std::get<0>(RegisterMask);
155   const uint16_t VFPMask = std::get<1>(RegisterMask);
156 
157   OS << '{';
158   bool Comma = false;
159   for (unsigned RI = 0, RE = 11; RI < RE; ++RI) {
160     if (GPRMask & (1 << RI)) {
161       if (Comma)
162         OS << ", ";
163       OS << GPRRegisterNames[RI];
164       Comma = true;
165     }
166   }
167   for (unsigned RI = 0, RE = 32; RI < RE; ++RI) {
168     if (VFPMask & (1 << RI)) {
169       if (Comma)
170         OS << ", ";
171       OS << "d" << unsigned(RI);
172       Comma = true;
173     }
174   }
175   for (unsigned RI = 11, RE = 16; RI < RE; ++RI) {
176     if (GPRMask & (1 << RI)) {
177       if (Comma)
178         OS << ", ";
179       OS << GPRRegisterNames[RI];
180       Comma = true;
181     }
182   }
183   OS << '}';
184 }
185 
186 ErrorOr<object::SectionRef>
getSectionContaining(const COFFObjectFile & COFF,uint64_t VA)187 Decoder::getSectionContaining(const COFFObjectFile &COFF, uint64_t VA) {
188   for (const auto &Section : COFF.sections()) {
189     uint64_t Address;
190     uint64_t Size;
191 
192     if (std::error_code EC = Section.getAddress(Address))
193       return EC;
194     if (std::error_code EC = Section.getSize(Size))
195       return EC;
196 
197     if (VA >= Address && (VA - Address) <= Size)
198       return Section;
199   }
200   return readobj_error::unknown_symbol;
201 }
202 
getSymbol(const COFFObjectFile & COFF,uint64_t VA,bool FunctionOnly)203 ErrorOr<object::SymbolRef> Decoder::getSymbol(const COFFObjectFile &COFF,
204                                               uint64_t VA, bool FunctionOnly) {
205   for (const auto &Symbol : COFF.symbols()) {
206     if (FunctionOnly) {
207       SymbolRef::Type Type;
208       if (std::error_code EC = Symbol.getType(Type))
209         return EC;
210       if (Type != SymbolRef::ST_Function)
211         continue;
212     }
213 
214     uint64_t Address;
215     if (std::error_code EC = Symbol.getAddress(Address))
216       return EC;
217     if (Address == VA)
218       return Symbol;
219   }
220   return readobj_error::unknown_symbol;
221 }
222 
getRelocatedSymbol(const COFFObjectFile &,const SectionRef & Section,uint64_t Offset)223 ErrorOr<SymbolRef> Decoder::getRelocatedSymbol(const COFFObjectFile &,
224                                                const SectionRef &Section,
225                                                uint64_t Offset) {
226   for (const auto &Relocation : Section.relocations()) {
227     uint64_t RelocationOffset;
228     if (auto Error = Relocation.getOffset(RelocationOffset))
229       return Error;
230     if (RelocationOffset == Offset)
231       return *Relocation.getSymbol();
232   }
233   return readobj_error::unknown_symbol;
234 }
235 
opcode_0xxxxxxx(const ulittle8_t * OC,unsigned & Offset,unsigned Length,bool Prologue)236 bool Decoder::opcode_0xxxxxxx(const ulittle8_t *OC, unsigned &Offset,
237                               unsigned Length, bool Prologue) {
238   uint8_t Imm = OC[Offset] & 0x7f;
239   SW.startLine() << format("0x%02x                ; %s sp, #(%u * 4)\n",
240                            OC[Offset],
241                            static_cast<const char *>(Prologue ? "sub" : "add"),
242                            Imm);
243   ++Offset;
244   return false;
245 }
246 
opcode_10Lxxxxx(const ulittle8_t * OC,unsigned & Offset,unsigned Length,bool Prologue)247 bool Decoder::opcode_10Lxxxxx(const ulittle8_t *OC, unsigned &Offset,
248                               unsigned Length, bool Prologue) {
249   unsigned Link = (OC[Offset] & 0x20) >> 5;
250   uint16_t RegisterMask = (Link << (Prologue ? 14 : 15))
251                         | ((OC[Offset + 0] & 0x1f) << 8)
252                         | ((OC[Offset + 1] & 0xff) << 0);
253   assert((~RegisterMask & (1 << 13)) && "sp must not be set");
254   assert((~RegisterMask & (1 << (Prologue ? 15 : 14))) && "pc must not be set");
255 
256   SW.startLine() << format("0x%02x 0x%02x           ; %s.w ",
257                            OC[Offset + 0], OC[Offset + 1],
258                            Prologue ? "push" : "pop");
259   printRegisters(std::make_pair(RegisterMask, 0));
260   OS << '\n';
261 
262   ++Offset, ++Offset;
263   return false;
264 }
265 
opcode_1100xxxx(const ulittle8_t * OC,unsigned & Offset,unsigned Length,bool Prologue)266 bool Decoder::opcode_1100xxxx(const ulittle8_t *OC, unsigned &Offset,
267                               unsigned Length, bool Prologue) {
268   if (Prologue)
269     SW.startLine() << format("0x%02x                ; mov r%u, sp\n",
270                              OC[Offset], OC[Offset] & 0xf);
271   else
272     SW.startLine() << format("0x%02x                ; mov sp, r%u\n",
273                              OC[Offset], OC[Offset] & 0xf);
274   ++Offset;
275   return false;
276 }
277 
opcode_11010Lxx(const ulittle8_t * OC,unsigned & Offset,unsigned Length,bool Prologue)278 bool Decoder::opcode_11010Lxx(const ulittle8_t *OC, unsigned &Offset,
279                               unsigned Length, bool Prologue) {
280   unsigned Link = (OC[Offset] & 0x4) >> 3;
281   unsigned Count = (OC[Offset] & 0x3);
282 
283   uint16_t GPRMask = (Link << (Prologue ? 14 : 15))
284                    | (((1 << (Count + 1)) - 1) << 4);
285 
286   SW.startLine() << format("0x%02x                ; %s ", OC[Offset],
287                            Prologue ? "push" : "pop");
288   printRegisters(std::make_pair(GPRMask, 0));
289   OS << '\n';
290 
291   ++Offset;
292   return false;
293 }
294 
opcode_11011Lxx(const ulittle8_t * OC,unsigned & Offset,unsigned Length,bool Prologue)295 bool Decoder::opcode_11011Lxx(const ulittle8_t *OC, unsigned &Offset,
296                               unsigned Length, bool Prologue) {
297   unsigned Link = (OC[Offset] & 0x4) >> 2;
298   unsigned Count = (OC[Offset] & 0x3) + 4;
299 
300   uint16_t GPRMask = (Link << (Prologue ? 14 : 15))
301                    | (((1 << (Count + 1)) - 1) << 4);
302 
303   SW.startLine() << format("0x%02x                ; %s.w ", OC[Offset],
304                            Prologue ? "push" : "pop");
305   printRegisters(std::make_pair(GPRMask, 0));
306   OS << '\n';
307 
308   ++Offset;
309   return false;
310 }
311 
opcode_11100xxx(const ulittle8_t * OC,unsigned & Offset,unsigned Length,bool Prologue)312 bool Decoder::opcode_11100xxx(const ulittle8_t *OC, unsigned &Offset,
313                               unsigned Length, bool Prologue) {
314   unsigned High = (OC[Offset] & 0x7);
315   uint32_t VFPMask = (((1 << (High + 1)) - 1) << 8);
316 
317   SW.startLine() << format("0x%02x                ; %s ", OC[Offset],
318                            Prologue ? "vpush" : "vpop");
319   printRegisters(std::make_pair(0, VFPMask));
320   OS << '\n';
321 
322   ++Offset;
323   return false;
324 }
325 
opcode_111010xx(const ulittle8_t * OC,unsigned & Offset,unsigned Length,bool Prologue)326 bool Decoder::opcode_111010xx(const ulittle8_t *OC, unsigned &Offset,
327                               unsigned Length, bool Prologue) {
328   uint16_t Imm = ((OC[Offset + 0] & 0x03) << 8) | ((OC[Offset + 1] & 0xff) << 0);
329 
330   SW.startLine() << format("0x%02x 0x%02x           ; %s.w sp, #(%u * 4)\n",
331                            OC[Offset + 0], OC[Offset + 1],
332                            static_cast<const char *>(Prologue ? "sub" : "add"),
333                            Imm);
334 
335   ++Offset, ++Offset;
336   return false;
337 }
338 
opcode_1110110L(const ulittle8_t * OC,unsigned & Offset,unsigned Length,bool Prologue)339 bool Decoder::opcode_1110110L(const ulittle8_t *OC, unsigned &Offset,
340                               unsigned Length, bool Prologue) {
341   uint8_t GPRMask = ((OC[Offset + 0] & 0x01) << (Prologue ? 14 : 15))
342                   | ((OC[Offset + 1] & 0xff) << 0);
343 
344   SW.startLine() << format("0x%02x 0x%02x           ; %s ", OC[Offset + 0],
345                            OC[Offset + 1], Prologue ? "push" : "pop");
346   printRegisters(std::make_pair(GPRMask, 0));
347   OS << '\n';
348 
349   ++Offset, ++Offset;
350   return false;
351 }
352 
opcode_11101110(const ulittle8_t * OC,unsigned & Offset,unsigned Length,bool Prologue)353 bool Decoder::opcode_11101110(const ulittle8_t *OC, unsigned &Offset,
354                               unsigned Length, bool Prologue) {
355   assert(!Prologue && "may not be used in prologue");
356 
357   if (OC[Offset + 1] & 0xf0)
358     SW.startLine() << format("0x%02x 0x%02x           ; reserved\n",
359                              OC[Offset + 0], OC[Offset +  1]);
360   else
361     SW.startLine()
362       << format("0x%02x 0x%02x           ; microsoft-specific (type: %u)\n",
363                 OC[Offset + 0], OC[Offset + 1], OC[Offset + 1] & 0x0f);
364 
365   ++Offset, ++Offset;
366   return false;
367 }
368 
opcode_11101111(const ulittle8_t * OC,unsigned & Offset,unsigned Length,bool Prologue)369 bool Decoder::opcode_11101111(const ulittle8_t *OC, unsigned &Offset,
370                               unsigned Length, bool Prologue) {
371   assert(!Prologue && "may not be used in prologue");
372 
373   if (OC[Offset + 1] & 0xf0)
374     SW.startLine() << format("0x%02x 0x%02x           ; reserved\n",
375                              OC[Offset + 0], OC[Offset +  1]);
376   else
377     SW.startLine()
378       << format("0x%02x 0x%02x           ; ldr.w lr, [sp], #%u\n",
379                 OC[Offset + 0], OC[Offset + 1], OC[Offset + 1] << 2);
380 
381   ++Offset, ++Offset;
382   return false;
383 }
384 
opcode_11110101(const ulittle8_t * OC,unsigned & Offset,unsigned Length,bool Prologue)385 bool Decoder::opcode_11110101(const ulittle8_t *OC, unsigned &Offset,
386                               unsigned Length, bool Prologue) {
387   unsigned Start = (OC[Offset + 1] & 0xf0) >> 4;
388   unsigned End = (OC[Offset + 1] & 0x0f) >> 0;
389   uint32_t VFPMask = ((1 << (End - Start)) - 1) << Start;
390 
391   SW.startLine() << format("0x%02x 0x%02x           ; %s ", OC[Offset + 0],
392                            OC[Offset + 1], Prologue ? "vpush" : "vpop");
393   printRegisters(std::make_pair(0, VFPMask));
394   OS << '\n';
395 
396   ++Offset, ++Offset;
397   return false;
398 }
399 
opcode_11110110(const ulittle8_t * OC,unsigned & Offset,unsigned Length,bool Prologue)400 bool Decoder::opcode_11110110(const ulittle8_t *OC, unsigned &Offset,
401                               unsigned Length, bool Prologue) {
402   unsigned Start = (OC[Offset + 1] & 0xf0) >> 4;
403   unsigned End = (OC[Offset + 1] & 0x0f) >> 0;
404   uint32_t VFPMask = ((1 << (End - Start)) - 1) << 16;
405 
406   SW.startLine() << format("0x%02x 0x%02x           ; %s ", OC[Offset + 0],
407                            OC[Offset + 1], Prologue ? "vpush" : "vpop");
408   printRegisters(std::make_pair(0, VFPMask));
409   OS << '\n';
410 
411   ++Offset, ++Offset;
412   return false;
413 }
414 
opcode_11110111(const ulittle8_t * OC,unsigned & Offset,unsigned Length,bool Prologue)415 bool Decoder::opcode_11110111(const ulittle8_t *OC, unsigned &Offset,
416                               unsigned Length, bool Prologue) {
417   uint32_t Imm = (OC[Offset + 1] << 8) | (OC[Offset + 2] << 0);
418 
419   SW.startLine() << format("0x%02x 0x%02x 0x%02x      ; %s sp, sp, #(%u * 4)\n",
420                            OC[Offset + 0], OC[Offset + 1], OC[Offset + 2],
421                            static_cast<const char *>(Prologue ? "sub" : "add"),
422                            Imm);
423 
424   ++Offset, ++Offset, ++Offset;
425   return false;
426 }
427 
opcode_11111000(const ulittle8_t * OC,unsigned & Offset,unsigned Length,bool Prologue)428 bool Decoder::opcode_11111000(const ulittle8_t *OC, unsigned &Offset,
429                               unsigned Length, bool Prologue) {
430   uint32_t Imm = (OC[Offset + 1] << 16)
431                | (OC[Offset + 2] << 8)
432                | (OC[Offset + 3] << 0);
433 
434   SW.startLine()
435     << format("0x%02x 0x%02x 0x%02x 0x%02x ; %s sp, sp, #(%u * 4)\n",
436               OC[Offset + 0], OC[Offset + 1], OC[Offset + 2], OC[Offset + 3],
437               static_cast<const char *>(Prologue ? "sub" : "add"), Imm);
438 
439   ++Offset, ++Offset, ++Offset, ++Offset;
440   return false;
441 }
442 
opcode_11111001(const ulittle8_t * OC,unsigned & Offset,unsigned Length,bool Prologue)443 bool Decoder::opcode_11111001(const ulittle8_t *OC, unsigned &Offset,
444                               unsigned Length, bool Prologue) {
445   uint32_t Imm = (OC[Offset + 1] << 8) | (OC[Offset + 2] << 0);
446 
447   SW.startLine()
448     << format("0x%02x 0x%02x 0x%02x      ; %s.w sp, sp, #(%u * 4)\n",
449               OC[Offset + 0], OC[Offset + 1], OC[Offset + 2],
450               static_cast<const char *>(Prologue ? "sub" : "add"), Imm);
451 
452   ++Offset, ++Offset, ++Offset;
453   return false;
454 }
455 
opcode_11111010(const ulittle8_t * OC,unsigned & Offset,unsigned Length,bool Prologue)456 bool Decoder::opcode_11111010(const ulittle8_t *OC, unsigned &Offset,
457                               unsigned Length, bool Prologue) {
458   uint32_t Imm = (OC[Offset + 1] << 16)
459                | (OC[Offset + 2] << 8)
460                | (OC[Offset + 3] << 0);
461 
462   SW.startLine()
463     << format("0x%02x 0x%02x 0x%02x 0x%02x ; %s.w sp, sp, #(%u * 4)\n",
464               OC[Offset + 0], OC[Offset + 1], OC[Offset + 2], OC[Offset + 3],
465               static_cast<const char *>(Prologue ? "sub" : "add"), Imm);
466 
467   ++Offset, ++Offset, ++Offset, ++Offset;
468   return false;
469 }
470 
opcode_11111011(const ulittle8_t * OC,unsigned & Offset,unsigned Length,bool Prologue)471 bool Decoder::opcode_11111011(const ulittle8_t *OC, unsigned &Offset,
472                               unsigned Length, bool Prologue) {
473   SW.startLine() << format("0x%02x                ; nop\n", OC[Offset]);
474   ++Offset;
475   return false;
476 }
477 
opcode_11111100(const ulittle8_t * OC,unsigned & Offset,unsigned Length,bool Prologue)478 bool Decoder::opcode_11111100(const ulittle8_t *OC, unsigned &Offset,
479                               unsigned Length, bool Prologue) {
480   SW.startLine() << format("0x%02x                ; nop.w\n", OC[Offset]);
481   ++Offset;
482   return false;
483 }
484 
opcode_11111101(const ulittle8_t * OC,unsigned & Offset,unsigned Length,bool Prologue)485 bool Decoder::opcode_11111101(const ulittle8_t *OC, unsigned &Offset,
486                               unsigned Length, bool Prologue) {
487   SW.startLine() << format("0x%02x                ; b\n", OC[Offset]);
488   ++Offset;
489   return true;
490 }
491 
opcode_11111110(const ulittle8_t * OC,unsigned & Offset,unsigned Length,bool Prologue)492 bool Decoder::opcode_11111110(const ulittle8_t *OC, unsigned &Offset,
493                               unsigned Length, bool Prologue) {
494   SW.startLine() << format("0x%02x                ; b.w\n", OC[Offset]);
495   ++Offset;
496   return true;
497 }
498 
opcode_11111111(const ulittle8_t * OC,unsigned & Offset,unsigned Length,bool Prologue)499 bool Decoder::opcode_11111111(const ulittle8_t *OC, unsigned &Offset,
500                               unsigned Length, bool Prologue) {
501   ++Offset;
502   return true;
503 }
504 
decodeOpcodes(ArrayRef<ulittle8_t> Opcodes,unsigned Offset,bool Prologue)505 void Decoder::decodeOpcodes(ArrayRef<ulittle8_t> Opcodes, unsigned Offset,
506                             bool Prologue) {
507   assert((!Prologue || Offset == 0) && "prologue should always use offset 0");
508 
509   bool Terminated = false;
510   for (unsigned OI = Offset, OE = Opcodes.size(); !Terminated && OI < OE; ) {
511     for (unsigned DI = 0;; ++DI) {
512       if ((Opcodes[OI] & Ring[DI].Mask) == Ring[DI].Value) {
513         Terminated = (this->*Ring[DI].Routine)(Opcodes.data(), OI, 0, Prologue);
514         break;
515       }
516       assert(DI < array_lengthof(Ring) && "unhandled opcode");
517     }
518   }
519 }
520 
dumpXDataRecord(const COFFObjectFile & COFF,const SectionRef & Section,uint64_t FunctionAddress,uint64_t VA)521 bool Decoder::dumpXDataRecord(const COFFObjectFile &COFF,
522                               const SectionRef &Section,
523                               uint64_t FunctionAddress, uint64_t VA) {
524   ArrayRef<uint8_t> Contents;
525   if (COFF.getSectionContents(COFF.getCOFFSection(Section), Contents))
526     return false;
527 
528   uint64_t SectionVA;
529   if (Section.getAddress(SectionVA))
530     return false;
531 
532   uint64_t Offset = VA - SectionVA;
533   const ulittle32_t *Data =
534     reinterpret_cast<const ulittle32_t *>(Contents.data() + Offset);
535   const ExceptionDataRecord XData(Data);
536 
537   DictScope XRS(SW, "ExceptionData");
538   SW.printNumber("FunctionLength", XData.FunctionLength() << 1);
539   SW.printNumber("Version", XData.Vers());
540   SW.printBoolean("ExceptionData", XData.X());
541   SW.printBoolean("EpiloguePacked", XData.E());
542   SW.printBoolean("Fragment", XData.F());
543   SW.printNumber(XData.E() ? "EpilogueOffset" : "EpilogueScopes",
544                  XData.EpilogueCount());
545   SW.printNumber("ByteCodeLength",
546                  static_cast<uint64_t>(XData.CodeWords() * sizeof(uint32_t)));
547 
548   if (XData.E()) {
549     ArrayRef<ulittle8_t> UC = XData.UnwindByteCode();
550     if (!XData.F()) {
551       ListScope PS(SW, "Prologue");
552       decodeOpcodes(UC, 0, /*Prologue=*/true);
553     }
554     if (XData.EpilogueCount()) {
555       ListScope ES(SW, "Epilogue");
556       decodeOpcodes(UC, XData.EpilogueCount(), /*Prologue=*/false);
557     }
558   } else {
559     ArrayRef<ulittle32_t> EpilogueScopes = XData.EpilogueScopes();
560     ListScope ESS(SW, "EpilogueScopes");
561     for (const EpilogueScope ES : EpilogueScopes) {
562       DictScope ESES(SW, "EpilogueScope");
563       SW.printNumber("StartOffset", ES.EpilogueStartOffset());
564       SW.printNumber("Condition", ES.Condition());
565       SW.printNumber("EpilogueStartIndex", ES.EpilogueStartIndex());
566 
567       ListScope Opcodes(SW, "Opcodes");
568       decodeOpcodes(XData.UnwindByteCode(), ES.EpilogueStartIndex(),
569                     /*Prologue=*/false);
570     }
571   }
572 
573   if (XData.X()) {
574     const uint32_t Address = XData.ExceptionHandlerRVA();
575     const uint32_t Parameter = XData.ExceptionHandlerParameter();
576     const size_t HandlerOffset = HeaderWords(XData)
577                                + (XData.E() ? 0 : XData.EpilogueCount())
578                                + XData.CodeWords();
579 
580     ErrorOr<SymbolRef> Symbol =
581       getRelocatedSymbol(COFF, Section, HandlerOffset * sizeof(uint32_t));
582     if (!Symbol)
583       Symbol = getSymbol(COFF, Address, /*FunctionOnly=*/true);
584 
585     StringRef Name;
586     if (Symbol)
587       Symbol->getName(Name);
588 
589     ListScope EHS(SW, "ExceptionHandler");
590     SW.printString("Routine", formatSymbol(Name, Address));
591     SW.printHex("Parameter", Parameter);
592   }
593 
594   return true;
595 }
596 
dumpUnpackedEntry(const COFFObjectFile & COFF,const SectionRef Section,uint64_t Offset,unsigned Index,const RuntimeFunction & RF)597 bool Decoder::dumpUnpackedEntry(const COFFObjectFile &COFF,
598                                 const SectionRef Section, uint64_t Offset,
599                                 unsigned Index, const RuntimeFunction &RF) {
600   assert(RF.Flag() == RuntimeFunctionFlag::RFF_Unpacked &&
601          "packed entry cannot be treated as an unpacked entry");
602 
603   ErrorOr<SymbolRef> Function = getRelocatedSymbol(COFF, Section, Offset);
604   if (!Function)
605     Function = getSymbol(COFF, RF.BeginAddress, /*FunctionOnly=*/true);
606 
607   ErrorOr<SymbolRef> XDataRecord = getRelocatedSymbol(COFF, Section, Offset + 4);
608   if (!XDataRecord)
609     XDataRecord = getSymbol(COFF, RF.ExceptionInformationRVA());
610 
611   if (!RF.BeginAddress && !Function)
612     return false;
613   if (!RF.UnwindData && !XDataRecord)
614     return false;
615 
616   StringRef FunctionName;
617   uint64_t FunctionAddress;
618   if (Function) {
619     Function->getName(FunctionName);
620     Function->getAddress(FunctionAddress);
621   } else {
622     const pe32_header *PEHeader;
623     if (COFF.getPE32Header(PEHeader))
624       return false;
625     FunctionAddress = PEHeader->ImageBase + RF.BeginAddress;
626   }
627 
628   SW.printString("Function", formatSymbol(FunctionName, FunctionAddress));
629 
630   if (XDataRecord) {
631     StringRef Name;
632     uint64_t Address;
633 
634     XDataRecord->getName(Name);
635     XDataRecord->getAddress(Address);
636 
637     SW.printString("ExceptionRecord", formatSymbol(Name, Address));
638 
639     section_iterator SI = COFF.section_end();
640     if (XDataRecord->getSection(SI))
641       return false;
642 
643     return dumpXDataRecord(COFF, *SI, FunctionAddress, Address);
644   } else {
645     const pe32_header *PEHeader;
646     if (COFF.getPE32Header(PEHeader))
647       return false;
648 
649     uint64_t Address = PEHeader->ImageBase + RF.ExceptionInformationRVA();
650     SW.printString("ExceptionRecord", formatSymbol("", Address));
651 
652     ErrorOr<SectionRef> Section =
653       getSectionContaining(COFF, RF.ExceptionInformationRVA());
654     if (!Section)
655       return false;
656 
657     return dumpXDataRecord(COFF, *Section, FunctionAddress,
658                            RF.ExceptionInformationRVA());
659   }
660 }
661 
dumpPackedEntry(const object::COFFObjectFile & COFF,const SectionRef Section,uint64_t Offset,unsigned Index,const RuntimeFunction & RF)662 bool Decoder::dumpPackedEntry(const object::COFFObjectFile &COFF,
663                               const SectionRef Section, uint64_t Offset,
664                               unsigned Index, const RuntimeFunction &RF) {
665   assert((RF.Flag() == RuntimeFunctionFlag::RFF_Packed ||
666           RF.Flag() == RuntimeFunctionFlag::RFF_PackedFragment) &&
667          "unpacked entry cannot be treated as a packed entry");
668 
669   ErrorOr<SymbolRef> Function = getRelocatedSymbol(COFF, Section, Offset);
670   if (!Function)
671     Function = getSymbol(COFF, RF.BeginAddress, /*FunctionOnly=*/true);
672 
673   StringRef FunctionName;
674   uint64_t FunctionAddress;
675   if (Function) {
676     Function->getName(FunctionName);
677     Function->getAddress(FunctionAddress);
678   } else {
679     const pe32_header *PEHeader;
680     if (COFF.getPE32Header(PEHeader))
681       return false;
682     FunctionAddress = PEHeader->ImageBase + RF.BeginAddress;
683   }
684 
685   SW.printString("Function", formatSymbol(FunctionName, FunctionAddress));
686   SW.printBoolean("Fragment",
687                   RF.Flag() == RuntimeFunctionFlag::RFF_PackedFragment);
688   SW.printNumber("FunctionLength", RF.FunctionLength());
689   SW.startLine() << "ReturnType: " << RF.Ret() << '\n';
690   SW.printBoolean("HomedParameters", RF.H());
691   SW.startLine() << "SavedRegisters: ";
692                  printRegisters(SavedRegisterMask(RF));
693   OS << '\n';
694   SW.printNumber("StackAdjustment", StackAdjustment(RF) << 2);
695 
696   return true;
697 }
698 
dumpProcedureDataEntry(const COFFObjectFile & COFF,const SectionRef Section,unsigned Index,ArrayRef<uint8_t> Contents)699 bool Decoder::dumpProcedureDataEntry(const COFFObjectFile &COFF,
700                                      const SectionRef Section, unsigned Index,
701                                      ArrayRef<uint8_t> Contents) {
702   uint64_t Offset = PDataEntrySize * Index;
703   const ulittle32_t *Data =
704     reinterpret_cast<const ulittle32_t *>(Contents.data() + Offset);
705 
706   const RuntimeFunction Entry(Data);
707   DictScope RFS(SW, "RuntimeFunction");
708   if (Entry.Flag() == RuntimeFunctionFlag::RFF_Unpacked)
709     return dumpUnpackedEntry(COFF, Section, Offset, Index, Entry);
710   return dumpPackedEntry(COFF, Section, Offset, Index, Entry);
711 }
712 
dumpProcedureData(const COFFObjectFile & COFF,const SectionRef Section)713 void Decoder::dumpProcedureData(const COFFObjectFile &COFF,
714                                 const SectionRef Section) {
715   ArrayRef<uint8_t> Contents;
716   if (COFF.getSectionContents(COFF.getCOFFSection(Section), Contents))
717     return;
718 
719   if (Contents.size() % PDataEntrySize) {
720     errs() << ".pdata content is not " << PDataEntrySize << "-byte aligned\n";
721     return;
722   }
723 
724   for (unsigned EI = 0, EE = Contents.size() / PDataEntrySize; EI < EE; ++EI)
725     if (!dumpProcedureDataEntry(COFF, Section, EI, Contents))
726       break;
727 }
728 
dumpProcedureData(const COFFObjectFile & COFF)729 std::error_code Decoder::dumpProcedureData(const COFFObjectFile &COFF) {
730   for (const auto &Section : COFF.sections()) {
731     StringRef SectionName;
732     if (std::error_code EC =
733             COFF.getSectionName(COFF.getCOFFSection(Section), SectionName))
734       return EC;
735 
736     if (SectionName.startswith(".pdata"))
737       dumpProcedureData(COFF, Section);
738   }
739   return std::error_code();
740 }
741 }
742 }
743 }
744 
745