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/STLExtras.h"
68 #include "llvm/ADT/StringExtras.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 = Section.getAddress();
190     uint64_t Size = Section.getSize();
191 
192     if (VA >= Address && (VA - Address) <= Size)
193       return Section;
194   }
195   return readobj_error::unknown_symbol;
196 }
197 
getSymbol(const COFFObjectFile & COFF,uint64_t VA,bool FunctionOnly)198 ErrorOr<object::SymbolRef> Decoder::getSymbol(const COFFObjectFile &COFF,
199                                               uint64_t VA, bool FunctionOnly) {
200   for (const auto &Symbol : COFF.symbols()) {
201     if (FunctionOnly) {
202       SymbolRef::Type Type;
203       if (std::error_code EC = Symbol.getType(Type))
204         return EC;
205       if (Type != SymbolRef::ST_Function)
206         continue;
207     }
208 
209     uint64_t Address;
210     if (std::error_code EC = Symbol.getAddress(Address))
211       return EC;
212     if (Address == VA)
213       return Symbol;
214   }
215   return readobj_error::unknown_symbol;
216 }
217 
getRelocatedSymbol(const COFFObjectFile &,const SectionRef & Section,uint64_t Offset)218 ErrorOr<SymbolRef> Decoder::getRelocatedSymbol(const COFFObjectFile &,
219                                                const SectionRef &Section,
220                                                uint64_t Offset) {
221   for (const auto &Relocation : Section.relocations()) {
222     uint64_t RelocationOffset;
223     if (auto Error = Relocation.getOffset(RelocationOffset))
224       return Error;
225     if (RelocationOffset == Offset)
226       return *Relocation.getSymbol();
227   }
228   return readobj_error::unknown_symbol;
229 }
230 
opcode_0xxxxxxx(const uint8_t * OC,unsigned & Offset,unsigned Length,bool Prologue)231 bool Decoder::opcode_0xxxxxxx(const uint8_t *OC, unsigned &Offset,
232                               unsigned Length, bool Prologue) {
233   uint8_t Imm = OC[Offset] & 0x7f;
234   SW.startLine() << format("0x%02x                ; %s sp, #(%u * 4)\n",
235                            OC[Offset],
236                            static_cast<const char *>(Prologue ? "sub" : "add"),
237                            Imm);
238   ++Offset;
239   return false;
240 }
241 
opcode_10Lxxxxx(const uint8_t * OC,unsigned & Offset,unsigned Length,bool Prologue)242 bool Decoder::opcode_10Lxxxxx(const uint8_t *OC, unsigned &Offset,
243                               unsigned Length, bool Prologue) {
244   unsigned Link = (OC[Offset] & 0x20) >> 5;
245   uint16_t RegisterMask = (Link << (Prologue ? 14 : 15))
246                         | ((OC[Offset + 0] & 0x1f) << 8)
247                         | ((OC[Offset + 1] & 0xff) << 0);
248   assert((~RegisterMask & (1 << 13)) && "sp must not be set");
249   assert((~RegisterMask & (1 << (Prologue ? 15 : 14))) && "pc must not be set");
250 
251   SW.startLine() << format("0x%02x 0x%02x           ; %s.w ",
252                            OC[Offset + 0], OC[Offset + 1],
253                            Prologue ? "push" : "pop");
254   printRegisters(std::make_pair(RegisterMask, 0));
255   OS << '\n';
256 
257   ++Offset, ++Offset;
258   return false;
259 }
260 
opcode_1100xxxx(const uint8_t * OC,unsigned & Offset,unsigned Length,bool Prologue)261 bool Decoder::opcode_1100xxxx(const uint8_t *OC, unsigned &Offset,
262                               unsigned Length, bool Prologue) {
263   if (Prologue)
264     SW.startLine() << format("0x%02x                ; mov r%u, sp\n",
265                              OC[Offset], OC[Offset] & 0xf);
266   else
267     SW.startLine() << format("0x%02x                ; mov sp, r%u\n",
268                              OC[Offset], OC[Offset] & 0xf);
269   ++Offset;
270   return false;
271 }
272 
opcode_11010Lxx(const uint8_t * OC,unsigned & Offset,unsigned Length,bool Prologue)273 bool Decoder::opcode_11010Lxx(const uint8_t *OC, unsigned &Offset,
274                               unsigned Length, bool Prologue) {
275   unsigned Link = (OC[Offset] & 0x4) >> 3;
276   unsigned Count = (OC[Offset] & 0x3);
277 
278   uint16_t GPRMask = (Link << (Prologue ? 14 : 15))
279                    | (((1 << (Count + 1)) - 1) << 4);
280 
281   SW.startLine() << format("0x%02x                ; %s ", OC[Offset],
282                            Prologue ? "push" : "pop");
283   printRegisters(std::make_pair(GPRMask, 0));
284   OS << '\n';
285 
286   ++Offset;
287   return false;
288 }
289 
opcode_11011Lxx(const uint8_t * OC,unsigned & Offset,unsigned Length,bool Prologue)290 bool Decoder::opcode_11011Lxx(const uint8_t *OC, unsigned &Offset,
291                               unsigned Length, bool Prologue) {
292   unsigned Link = (OC[Offset] & 0x4) >> 2;
293   unsigned Count = (OC[Offset] & 0x3) + 4;
294 
295   uint16_t GPRMask = (Link << (Prologue ? 14 : 15))
296                    | (((1 << (Count + 1)) - 1) << 4);
297 
298   SW.startLine() << format("0x%02x                ; %s.w ", OC[Offset],
299                            Prologue ? "push" : "pop");
300   printRegisters(std::make_pair(GPRMask, 0));
301   OS << '\n';
302 
303   ++Offset;
304   return false;
305 }
306 
opcode_11100xxx(const uint8_t * OC,unsigned & Offset,unsigned Length,bool Prologue)307 bool Decoder::opcode_11100xxx(const uint8_t *OC, unsigned &Offset,
308                               unsigned Length, bool Prologue) {
309   unsigned High = (OC[Offset] & 0x7);
310   uint32_t VFPMask = (((1 << (High + 1)) - 1) << 8);
311 
312   SW.startLine() << format("0x%02x                ; %s ", OC[Offset],
313                            Prologue ? "vpush" : "vpop");
314   printRegisters(std::make_pair(0, VFPMask));
315   OS << '\n';
316 
317   ++Offset;
318   return false;
319 }
320 
opcode_111010xx(const uint8_t * OC,unsigned & Offset,unsigned Length,bool Prologue)321 bool Decoder::opcode_111010xx(const uint8_t *OC, unsigned &Offset,
322                               unsigned Length, bool Prologue) {
323   uint16_t Imm = ((OC[Offset + 0] & 0x03) << 8) | ((OC[Offset + 1] & 0xff) << 0);
324 
325   SW.startLine() << format("0x%02x 0x%02x           ; %s.w sp, #(%u * 4)\n",
326                            OC[Offset + 0], OC[Offset + 1],
327                            static_cast<const char *>(Prologue ? "sub" : "add"),
328                            Imm);
329 
330   ++Offset, ++Offset;
331   return false;
332 }
333 
opcode_1110110L(const uint8_t * OC,unsigned & Offset,unsigned Length,bool Prologue)334 bool Decoder::opcode_1110110L(const uint8_t *OC, unsigned &Offset,
335                               unsigned Length, bool Prologue) {
336   uint8_t GPRMask = ((OC[Offset + 0] & 0x01) << (Prologue ? 14 : 15))
337                   | ((OC[Offset + 1] & 0xff) << 0);
338 
339   SW.startLine() << format("0x%02x 0x%02x           ; %s ", OC[Offset + 0],
340                            OC[Offset + 1], Prologue ? "push" : "pop");
341   printRegisters(std::make_pair(GPRMask, 0));
342   OS << '\n';
343 
344   ++Offset, ++Offset;
345   return false;
346 }
347 
opcode_11101110(const uint8_t * OC,unsigned & Offset,unsigned Length,bool Prologue)348 bool Decoder::opcode_11101110(const uint8_t *OC, unsigned &Offset,
349                               unsigned Length, bool Prologue) {
350   assert(!Prologue && "may not be used in prologue");
351 
352   if (OC[Offset + 1] & 0xf0)
353     SW.startLine() << format("0x%02x 0x%02x           ; reserved\n",
354                              OC[Offset + 0], OC[Offset +  1]);
355   else
356     SW.startLine()
357       << format("0x%02x 0x%02x           ; microsoft-specific (type: %u)\n",
358                 OC[Offset + 0], OC[Offset + 1], OC[Offset + 1] & 0x0f);
359 
360   ++Offset, ++Offset;
361   return false;
362 }
363 
opcode_11101111(const uint8_t * OC,unsigned & Offset,unsigned Length,bool Prologue)364 bool Decoder::opcode_11101111(const uint8_t *OC, unsigned &Offset,
365                               unsigned Length, bool Prologue) {
366   assert(!Prologue && "may not be used in prologue");
367 
368   if (OC[Offset + 1] & 0xf0)
369     SW.startLine() << format("0x%02x 0x%02x           ; reserved\n",
370                              OC[Offset + 0], OC[Offset +  1]);
371   else
372     SW.startLine()
373       << format("0x%02x 0x%02x           ; ldr.w lr, [sp], #%u\n",
374                 OC[Offset + 0], OC[Offset + 1], OC[Offset + 1] << 2);
375 
376   ++Offset, ++Offset;
377   return false;
378 }
379 
opcode_11110101(const uint8_t * OC,unsigned & Offset,unsigned Length,bool Prologue)380 bool Decoder::opcode_11110101(const uint8_t *OC, unsigned &Offset,
381                               unsigned Length, bool Prologue) {
382   unsigned Start = (OC[Offset + 1] & 0xf0) >> 4;
383   unsigned End = (OC[Offset + 1] & 0x0f) >> 0;
384   uint32_t VFPMask = ((1 << (End - Start)) - 1) << Start;
385 
386   SW.startLine() << format("0x%02x 0x%02x           ; %s ", OC[Offset + 0],
387                            OC[Offset + 1], Prologue ? "vpush" : "vpop");
388   printRegisters(std::make_pair(0, VFPMask));
389   OS << '\n';
390 
391   ++Offset, ++Offset;
392   return false;
393 }
394 
opcode_11110110(const uint8_t * OC,unsigned & Offset,unsigned Length,bool Prologue)395 bool Decoder::opcode_11110110(const uint8_t *OC, unsigned &Offset,
396                               unsigned Length, bool Prologue) {
397   unsigned Start = (OC[Offset + 1] & 0xf0) >> 4;
398   unsigned End = (OC[Offset + 1] & 0x0f) >> 0;
399   uint32_t VFPMask = ((1 << (End - Start)) - 1) << 16;
400 
401   SW.startLine() << format("0x%02x 0x%02x           ; %s ", OC[Offset + 0],
402                            OC[Offset + 1], Prologue ? "vpush" : "vpop");
403   printRegisters(std::make_pair(0, VFPMask));
404   OS << '\n';
405 
406   ++Offset, ++Offset;
407   return false;
408 }
409 
opcode_11110111(const uint8_t * OC,unsigned & Offset,unsigned Length,bool Prologue)410 bool Decoder::opcode_11110111(const uint8_t *OC, unsigned &Offset,
411                               unsigned Length, bool Prologue) {
412   uint32_t Imm = (OC[Offset + 1] << 8) | (OC[Offset + 2] << 0);
413 
414   SW.startLine() << format("0x%02x 0x%02x 0x%02x      ; %s sp, sp, #(%u * 4)\n",
415                            OC[Offset + 0], OC[Offset + 1], OC[Offset + 2],
416                            static_cast<const char *>(Prologue ? "sub" : "add"),
417                            Imm);
418 
419   ++Offset, ++Offset, ++Offset;
420   return false;
421 }
422 
opcode_11111000(const uint8_t * OC,unsigned & Offset,unsigned Length,bool Prologue)423 bool Decoder::opcode_11111000(const uint8_t *OC, unsigned &Offset,
424                               unsigned Length, bool Prologue) {
425   uint32_t Imm = (OC[Offset + 1] << 16)
426                | (OC[Offset + 2] << 8)
427                | (OC[Offset + 3] << 0);
428 
429   SW.startLine()
430     << format("0x%02x 0x%02x 0x%02x 0x%02x ; %s sp, sp, #(%u * 4)\n",
431               OC[Offset + 0], OC[Offset + 1], OC[Offset + 2], OC[Offset + 3],
432               static_cast<const char *>(Prologue ? "sub" : "add"), Imm);
433 
434   ++Offset, ++Offset, ++Offset, ++Offset;
435   return false;
436 }
437 
opcode_11111001(const uint8_t * OC,unsigned & Offset,unsigned Length,bool Prologue)438 bool Decoder::opcode_11111001(const uint8_t *OC, unsigned &Offset,
439                               unsigned Length, bool Prologue) {
440   uint32_t Imm = (OC[Offset + 1] << 8) | (OC[Offset + 2] << 0);
441 
442   SW.startLine()
443     << format("0x%02x 0x%02x 0x%02x      ; %s.w sp, sp, #(%u * 4)\n",
444               OC[Offset + 0], OC[Offset + 1], OC[Offset + 2],
445               static_cast<const char *>(Prologue ? "sub" : "add"), Imm);
446 
447   ++Offset, ++Offset, ++Offset;
448   return false;
449 }
450 
opcode_11111010(const uint8_t * OC,unsigned & Offset,unsigned Length,bool Prologue)451 bool Decoder::opcode_11111010(const uint8_t *OC, unsigned &Offset,
452                               unsigned Length, bool Prologue) {
453   uint32_t Imm = (OC[Offset + 1] << 16)
454                | (OC[Offset + 2] << 8)
455                | (OC[Offset + 3] << 0);
456 
457   SW.startLine()
458     << format("0x%02x 0x%02x 0x%02x 0x%02x ; %s.w sp, sp, #(%u * 4)\n",
459               OC[Offset + 0], OC[Offset + 1], OC[Offset + 2], OC[Offset + 3],
460               static_cast<const char *>(Prologue ? "sub" : "add"), Imm);
461 
462   ++Offset, ++Offset, ++Offset, ++Offset;
463   return false;
464 }
465 
opcode_11111011(const uint8_t * OC,unsigned & Offset,unsigned Length,bool Prologue)466 bool Decoder::opcode_11111011(const uint8_t *OC, unsigned &Offset,
467                               unsigned Length, bool Prologue) {
468   SW.startLine() << format("0x%02x                ; nop\n", OC[Offset]);
469   ++Offset;
470   return false;
471 }
472 
opcode_11111100(const uint8_t * OC,unsigned & Offset,unsigned Length,bool Prologue)473 bool Decoder::opcode_11111100(const uint8_t *OC, unsigned &Offset,
474                               unsigned Length, bool Prologue) {
475   SW.startLine() << format("0x%02x                ; nop.w\n", OC[Offset]);
476   ++Offset;
477   return false;
478 }
479 
opcode_11111101(const uint8_t * OC,unsigned & Offset,unsigned Length,bool Prologue)480 bool Decoder::opcode_11111101(const uint8_t *OC, unsigned &Offset,
481                               unsigned Length, bool Prologue) {
482   SW.startLine() << format("0x%02x                ; b\n", OC[Offset]);
483   ++Offset;
484   return true;
485 }
486 
opcode_11111110(const uint8_t * OC,unsigned & Offset,unsigned Length,bool Prologue)487 bool Decoder::opcode_11111110(const uint8_t *OC, unsigned &Offset,
488                               unsigned Length, bool Prologue) {
489   SW.startLine() << format("0x%02x                ; b.w\n", OC[Offset]);
490   ++Offset;
491   return true;
492 }
493 
opcode_11111111(const uint8_t * OC,unsigned & Offset,unsigned Length,bool Prologue)494 bool Decoder::opcode_11111111(const uint8_t *OC, unsigned &Offset,
495                               unsigned Length, bool Prologue) {
496   ++Offset;
497   return true;
498 }
499 
decodeOpcodes(ArrayRef<uint8_t> Opcodes,unsigned Offset,bool Prologue)500 void Decoder::decodeOpcodes(ArrayRef<uint8_t> Opcodes, unsigned Offset,
501                             bool Prologue) {
502   assert((!Prologue || Offset == 0) && "prologue should always use offset 0");
503 
504   bool Terminated = false;
505   for (unsigned OI = Offset, OE = Opcodes.size(); !Terminated && OI < OE; ) {
506     for (unsigned DI = 0;; ++DI) {
507       if ((Opcodes[OI] & Ring[DI].Mask) == Ring[DI].Value) {
508         Terminated = (this->*Ring[DI].Routine)(Opcodes.data(), OI, 0, Prologue);
509         break;
510       }
511       assert(DI < array_lengthof(Ring) && "unhandled opcode");
512     }
513   }
514 }
515 
dumpXDataRecord(const COFFObjectFile & COFF,const SectionRef & Section,uint64_t FunctionAddress,uint64_t VA)516 bool Decoder::dumpXDataRecord(const COFFObjectFile &COFF,
517                               const SectionRef &Section,
518                               uint64_t FunctionAddress, uint64_t VA) {
519   ArrayRef<uint8_t> Contents;
520   if (COFF.getSectionContents(COFF.getCOFFSection(Section), Contents))
521     return false;
522 
523   uint64_t SectionVA = Section.getAddress();
524   uint64_t Offset = VA - SectionVA;
525   const ulittle32_t *Data =
526     reinterpret_cast<const ulittle32_t *>(Contents.data() + Offset);
527   const ExceptionDataRecord XData(Data);
528 
529   DictScope XRS(SW, "ExceptionData");
530   SW.printNumber("FunctionLength", XData.FunctionLength() << 1);
531   SW.printNumber("Version", XData.Vers());
532   SW.printBoolean("ExceptionData", XData.X());
533   SW.printBoolean("EpiloguePacked", XData.E());
534   SW.printBoolean("Fragment", XData.F());
535   SW.printNumber(XData.E() ? "EpilogueOffset" : "EpilogueScopes",
536                  XData.EpilogueCount());
537   SW.printNumber("ByteCodeLength",
538                  static_cast<uint64_t>(XData.CodeWords() * sizeof(uint32_t)));
539 
540   if (XData.E()) {
541     ArrayRef<uint8_t> UC = XData.UnwindByteCode();
542     if (!XData.F()) {
543       ListScope PS(SW, "Prologue");
544       decodeOpcodes(UC, 0, /*Prologue=*/true);
545     }
546     if (XData.EpilogueCount()) {
547       ListScope ES(SW, "Epilogue");
548       decodeOpcodes(UC, XData.EpilogueCount(), /*Prologue=*/false);
549     }
550   } else {
551     ArrayRef<ulittle32_t> EpilogueScopes = XData.EpilogueScopes();
552     ListScope ESS(SW, "EpilogueScopes");
553     for (const EpilogueScope ES : EpilogueScopes) {
554       DictScope ESES(SW, "EpilogueScope");
555       SW.printNumber("StartOffset", ES.EpilogueStartOffset());
556       SW.printNumber("Condition", ES.Condition());
557       SW.printNumber("EpilogueStartIndex", ES.EpilogueStartIndex());
558 
559       ListScope Opcodes(SW, "Opcodes");
560       decodeOpcodes(XData.UnwindByteCode(), ES.EpilogueStartIndex(),
561                     /*Prologue=*/false);
562     }
563   }
564 
565   if (XData.X()) {
566     const uint32_t Address = XData.ExceptionHandlerRVA();
567     const uint32_t Parameter = XData.ExceptionHandlerParameter();
568     const size_t HandlerOffset = HeaderWords(XData)
569                                + (XData.E() ? 0 : XData.EpilogueCount())
570                                + XData.CodeWords();
571 
572     ErrorOr<SymbolRef> Symbol =
573       getRelocatedSymbol(COFF, Section, HandlerOffset * sizeof(uint32_t));
574     if (!Symbol)
575       Symbol = getSymbol(COFF, Address, /*FunctionOnly=*/true);
576 
577     StringRef Name;
578     if (Symbol)
579       Symbol->getName(Name);
580 
581     ListScope EHS(SW, "ExceptionHandler");
582     SW.printString("Routine", formatSymbol(Name, Address));
583     SW.printHex("Parameter", Parameter);
584   }
585 
586   return true;
587 }
588 
dumpUnpackedEntry(const COFFObjectFile & COFF,const SectionRef Section,uint64_t Offset,unsigned Index,const RuntimeFunction & RF)589 bool Decoder::dumpUnpackedEntry(const COFFObjectFile &COFF,
590                                 const SectionRef Section, uint64_t Offset,
591                                 unsigned Index, const RuntimeFunction &RF) {
592   assert(RF.Flag() == RuntimeFunctionFlag::RFF_Unpacked &&
593          "packed entry cannot be treated as an unpacked entry");
594 
595   ErrorOr<SymbolRef> Function = getRelocatedSymbol(COFF, Section, Offset);
596   if (!Function)
597     Function = getSymbol(COFF, RF.BeginAddress, /*FunctionOnly=*/true);
598 
599   ErrorOr<SymbolRef> XDataRecord = getRelocatedSymbol(COFF, Section, Offset + 4);
600   if (!XDataRecord)
601     XDataRecord = getSymbol(COFF, RF.ExceptionInformationRVA());
602 
603   if (!RF.BeginAddress && !Function)
604     return false;
605   if (!RF.UnwindData && !XDataRecord)
606     return false;
607 
608   StringRef FunctionName;
609   uint64_t FunctionAddress;
610   if (Function) {
611     Function->getName(FunctionName);
612     Function->getAddress(FunctionAddress);
613   } else {
614     const pe32_header *PEHeader;
615     if (COFF.getPE32Header(PEHeader))
616       return false;
617     FunctionAddress = PEHeader->ImageBase + RF.BeginAddress;
618   }
619 
620   SW.printString("Function", formatSymbol(FunctionName, FunctionAddress));
621 
622   if (XDataRecord) {
623     StringRef Name;
624     uint64_t Address;
625 
626     XDataRecord->getName(Name);
627     XDataRecord->getAddress(Address);
628 
629     SW.printString("ExceptionRecord", formatSymbol(Name, Address));
630 
631     section_iterator SI = COFF.section_end();
632     if (XDataRecord->getSection(SI))
633       return false;
634 
635     return dumpXDataRecord(COFF, *SI, FunctionAddress, Address);
636   } else {
637     const pe32_header *PEHeader;
638     if (COFF.getPE32Header(PEHeader))
639       return false;
640 
641     uint64_t Address = PEHeader->ImageBase + RF.ExceptionInformationRVA();
642     SW.printString("ExceptionRecord", formatSymbol("", Address));
643 
644     ErrorOr<SectionRef> Section =
645       getSectionContaining(COFF, RF.ExceptionInformationRVA());
646     if (!Section)
647       return false;
648 
649     return dumpXDataRecord(COFF, *Section, FunctionAddress,
650                            RF.ExceptionInformationRVA());
651   }
652 }
653 
dumpPackedEntry(const object::COFFObjectFile & COFF,const SectionRef Section,uint64_t Offset,unsigned Index,const RuntimeFunction & RF)654 bool Decoder::dumpPackedEntry(const object::COFFObjectFile &COFF,
655                               const SectionRef Section, uint64_t Offset,
656                               unsigned Index, const RuntimeFunction &RF) {
657   assert((RF.Flag() == RuntimeFunctionFlag::RFF_Packed ||
658           RF.Flag() == RuntimeFunctionFlag::RFF_PackedFragment) &&
659          "unpacked entry cannot be treated as a packed entry");
660 
661   ErrorOr<SymbolRef> Function = getRelocatedSymbol(COFF, Section, Offset);
662   if (!Function)
663     Function = getSymbol(COFF, RF.BeginAddress, /*FunctionOnly=*/true);
664 
665   StringRef FunctionName;
666   uint64_t FunctionAddress;
667   if (Function) {
668     Function->getName(FunctionName);
669     Function->getAddress(FunctionAddress);
670   } else {
671     const pe32_header *PEHeader;
672     if (COFF.getPE32Header(PEHeader))
673       return false;
674     FunctionAddress = PEHeader->ImageBase + RF.BeginAddress;
675   }
676 
677   SW.printString("Function", formatSymbol(FunctionName, FunctionAddress));
678   SW.printBoolean("Fragment",
679                   RF.Flag() == RuntimeFunctionFlag::RFF_PackedFragment);
680   SW.printNumber("FunctionLength", RF.FunctionLength());
681   SW.startLine() << "ReturnType: " << RF.Ret() << '\n';
682   SW.printBoolean("HomedParameters", RF.H());
683   SW.startLine() << "SavedRegisters: ";
684                  printRegisters(SavedRegisterMask(RF));
685   OS << '\n';
686   SW.printNumber("StackAdjustment", StackAdjustment(RF) << 2);
687 
688   return true;
689 }
690 
dumpProcedureDataEntry(const COFFObjectFile & COFF,const SectionRef Section,unsigned Index,ArrayRef<uint8_t> Contents)691 bool Decoder::dumpProcedureDataEntry(const COFFObjectFile &COFF,
692                                      const SectionRef Section, unsigned Index,
693                                      ArrayRef<uint8_t> Contents) {
694   uint64_t Offset = PDataEntrySize * Index;
695   const ulittle32_t *Data =
696     reinterpret_cast<const ulittle32_t *>(Contents.data() + Offset);
697 
698   const RuntimeFunction Entry(Data);
699   DictScope RFS(SW, "RuntimeFunction");
700   if (Entry.Flag() == RuntimeFunctionFlag::RFF_Unpacked)
701     return dumpUnpackedEntry(COFF, Section, Offset, Index, Entry);
702   return dumpPackedEntry(COFF, Section, Offset, Index, Entry);
703 }
704 
dumpProcedureData(const COFFObjectFile & COFF,const SectionRef Section)705 void Decoder::dumpProcedureData(const COFFObjectFile &COFF,
706                                 const SectionRef Section) {
707   ArrayRef<uint8_t> Contents;
708   if (COFF.getSectionContents(COFF.getCOFFSection(Section), Contents))
709     return;
710 
711   if (Contents.size() % PDataEntrySize) {
712     errs() << ".pdata content is not " << PDataEntrySize << "-byte aligned\n";
713     return;
714   }
715 
716   for (unsigned EI = 0, EE = Contents.size() / PDataEntrySize; EI < EE; ++EI)
717     if (!dumpProcedureDataEntry(COFF, Section, EI, Contents))
718       break;
719 }
720 
dumpProcedureData(const COFFObjectFile & COFF)721 std::error_code Decoder::dumpProcedureData(const COFFObjectFile &COFF) {
722   for (const auto &Section : COFF.sections()) {
723     StringRef SectionName;
724     if (std::error_code EC =
725             COFF.getSectionName(COFF.getCOFFSection(Section), SectionName))
726       return EC;
727 
728     if (SectionName.startswith(".pdata"))
729       dumpProcedureData(COFF, Section);
730   }
731   return std::error_code();
732 }
733 }
734 }
735 }
736