1//===- Win64EHDumper.cpp - Win64 EH 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#include "Win64EHDumper.h"
11#include "llvm-readobj.h"
12#include "llvm/Object/COFF.h"
13#include "llvm/Support/ErrorHandling.h"
14#include "llvm/Support/Format.h"
15
16using namespace llvm;
17using namespace llvm::object;
18using namespace llvm::Win64EH;
19
20static const EnumEntry<unsigned> UnwindFlags[] = {
21  { "ExceptionHandler", UNW_ExceptionHandler },
22  { "TerminateHandler", UNW_TerminateHandler },
23  { "ChainInfo"       , UNW_ChainInfo        }
24};
25
26static const EnumEntry<unsigned> UnwindOpInfo[] = {
27  { "RAX",  0 },
28  { "RCX",  1 },
29  { "RDX",  2 },
30  { "RBX",  3 },
31  { "RSP",  4 },
32  { "RBP",  5 },
33  { "RSI",  6 },
34  { "RDI",  7 },
35  { "R8",   8 },
36  { "R9",   9 },
37  { "R10", 10 },
38  { "R11", 11 },
39  { "R12", 12 },
40  { "R13", 13 },
41  { "R14", 14 },
42  { "R15", 15 }
43};
44
45static uint64_t getOffsetOfLSDA(const UnwindInfo& UI) {
46  return static_cast<const char*>(UI.getLanguageSpecificData())
47         - reinterpret_cast<const char*>(&UI);
48}
49
50static uint32_t getLargeSlotValue(ArrayRef<UnwindCode> UC) {
51  if (UC.size() < 3)
52    return 0;
53  return UC[1].FrameOffset + (static_cast<uint32_t>(UC[2].FrameOffset) << 16);
54}
55
56// Returns the name of the unwind code.
57static StringRef getUnwindCodeTypeName(uint8_t Code) {
58  switch (Code) {
59  default: llvm_unreachable("Invalid unwind code");
60  case UOP_PushNonVol: return "PUSH_NONVOL";
61  case UOP_AllocLarge: return "ALLOC_LARGE";
62  case UOP_AllocSmall: return "ALLOC_SMALL";
63  case UOP_SetFPReg: return "SET_FPREG";
64  case UOP_SaveNonVol: return "SAVE_NONVOL";
65  case UOP_SaveNonVolBig: return "SAVE_NONVOL_FAR";
66  case UOP_SaveXMM128: return "SAVE_XMM128";
67  case UOP_SaveXMM128Big: return "SAVE_XMM128_FAR";
68  case UOP_PushMachFrame: return "PUSH_MACHFRAME";
69  }
70}
71
72// Returns the name of a referenced register.
73static StringRef getUnwindRegisterName(uint8_t Reg) {
74  switch (Reg) {
75  default: llvm_unreachable("Invalid register");
76  case 0: return "RAX";
77  case 1: return "RCX";
78  case 2: return "RDX";
79  case 3: return "RBX";
80  case 4: return "RSP";
81  case 5: return "RBP";
82  case 6: return "RSI";
83  case 7: return "RDI";
84  case 8: return "R8";
85  case 9: return "R9";
86  case 10: return "R10";
87  case 11: return "R11";
88  case 12: return "R12";
89  case 13: return "R13";
90  case 14: return "R14";
91  case 15: return "R15";
92  }
93}
94
95// Calculates the number of array slots required for the unwind code.
96static unsigned getNumUsedSlots(const UnwindCode &UnwindCode) {
97  switch (UnwindCode.getUnwindOp()) {
98  default: llvm_unreachable("Invalid unwind code");
99  case UOP_PushNonVol:
100  case UOP_AllocSmall:
101  case UOP_SetFPReg:
102  case UOP_PushMachFrame:
103    return 1;
104  case UOP_SaveNonVol:
105  case UOP_SaveXMM128:
106    return 2;
107  case UOP_SaveNonVolBig:
108  case UOP_SaveXMM128Big:
109    return 3;
110  case UOP_AllocLarge:
111    return (UnwindCode.getOpInfo() == 0) ? 2 : 3;
112  }
113}
114
115static std::string formatSymbol(const Dumper::Context &Ctx,
116                                const coff_section *Section, uint64_t Offset,
117                                uint32_t Displacement) {
118  std::string Buffer;
119  raw_string_ostream OS(Buffer);
120
121  SymbolRef Symbol;
122  if (!Ctx.ResolveSymbol(Section, Offset, Symbol, Ctx.UserData)) {
123    Expected<StringRef> Name = Symbol.getName();
124    if (Name) {
125      OS << *Name;
126      if (Displacement > 0)
127        OS << format(" +0x%X (0x%" PRIX64 ")", Displacement, Offset);
128      else
129        OS << format(" (0x%" PRIX64 ")", Offset);
130      return OS.str();
131    } else {
132      // TODO: Actually report errors helpfully.
133      consumeError(Name.takeError());
134    }
135  }
136
137  OS << format(" (0x%" PRIX64 ")", Offset);
138  return OS.str();
139}
140
141static std::error_code resolveRelocation(const Dumper::Context &Ctx,
142                                         const coff_section *Section,
143                                         uint64_t Offset,
144                                         const coff_section *&ResolvedSection,
145                                         uint64_t &ResolvedAddress) {
146  SymbolRef Symbol;
147  if (std::error_code EC =
148          Ctx.ResolveSymbol(Section, Offset, Symbol, Ctx.UserData))
149    return EC;
150
151  Expected<uint64_t> ResolvedAddressOrErr = Symbol.getAddress();
152  if (!ResolvedAddressOrErr)
153    return errorToErrorCode(ResolvedAddressOrErr.takeError());
154  ResolvedAddress = *ResolvedAddressOrErr;
155
156  Expected<section_iterator> SI = Symbol.getSection();
157  if (!SI)
158    return errorToErrorCode(SI.takeError());
159  ResolvedSection = Ctx.COFF.getCOFFSection(**SI);
160  return std::error_code();
161}
162
163namespace llvm {
164namespace Win64EH {
165void Dumper::printRuntimeFunctionEntry(const Context &Ctx,
166                                       const coff_section *Section,
167                                       uint64_t Offset,
168                                       const RuntimeFunction &RF) {
169  SW.printString("StartAddress",
170                 formatSymbol(Ctx, Section, Offset + 0, RF.StartAddress));
171  SW.printString("EndAddress",
172                 formatSymbol(Ctx, Section, Offset + 4, RF.EndAddress));
173  SW.printString("UnwindInfoAddress",
174                 formatSymbol(Ctx, Section, Offset + 8, RF.UnwindInfoOffset));
175}
176
177// Prints one unwind code. Because an unwind code can occupy up to 3 slots in
178// the unwind codes array, this function requires that the correct number of
179// slots is provided.
180void Dumper::printUnwindCode(const UnwindInfo& UI, ArrayRef<UnwindCode> UC) {
181  assert(UC.size() >= getNumUsedSlots(UC[0]));
182
183  SW.startLine() << format("0x%02X: ", unsigned(UC[0].u.CodeOffset))
184                 << getUnwindCodeTypeName(UC[0].getUnwindOp());
185
186  switch (UC[0].getUnwindOp()) {
187  case UOP_PushNonVol:
188    OS << " reg=" << getUnwindRegisterName(UC[0].getOpInfo());
189    break;
190
191  case UOP_AllocLarge:
192    OS << " size="
193       << ((UC[0].getOpInfo() == 0) ? UC[1].FrameOffset * 8
194                                    : getLargeSlotValue(UC));
195    break;
196
197  case UOP_AllocSmall:
198    OS << " size=" << (UC[0].getOpInfo() + 1) * 8;
199    break;
200
201  case UOP_SetFPReg:
202    if (UI.getFrameRegister() == 0)
203      OS << " reg=<invalid>";
204    else
205      OS << " reg=" << getUnwindRegisterName(UI.getFrameRegister())
206         << format(", offset=0x%X", UI.getFrameOffset() * 16);
207    break;
208
209  case UOP_SaveNonVol:
210    OS << " reg=" << getUnwindRegisterName(UC[0].getOpInfo())
211       << format(", offset=0x%X", UC[1].FrameOffset * 8);
212    break;
213
214  case UOP_SaveNonVolBig:
215    OS << " reg=" << getUnwindRegisterName(UC[0].getOpInfo())
216       << format(", offset=0x%X", getLargeSlotValue(UC));
217    break;
218
219  case UOP_SaveXMM128:
220    OS << " reg=XMM" << static_cast<uint32_t>(UC[0].getOpInfo())
221       << format(", offset=0x%X", UC[1].FrameOffset * 16);
222    break;
223
224  case UOP_SaveXMM128Big:
225    OS << " reg=XMM" << static_cast<uint32_t>(UC[0].getOpInfo())
226       << format(", offset=0x%X", getLargeSlotValue(UC));
227    break;
228
229  case UOP_PushMachFrame:
230    OS << " errcode=" << (UC[0].getOpInfo() == 0 ? "no" : "yes");
231    break;
232  }
233
234  OS << "\n";
235}
236
237void Dumper::printUnwindInfo(const Context &Ctx, const coff_section *Section,
238                             off_t Offset, const UnwindInfo &UI) {
239  DictScope UIS(SW, "UnwindInfo");
240  SW.printNumber("Version", UI.getVersion());
241  SW.printFlags("Flags", UI.getFlags(), makeArrayRef(UnwindFlags));
242  SW.printNumber("PrologSize", UI.PrologSize);
243  if (UI.getFrameRegister()) {
244    SW.printEnum("FrameRegister", UI.getFrameRegister(),
245                 makeArrayRef(UnwindOpInfo));
246    SW.printHex("FrameOffset", UI.getFrameOffset());
247  } else {
248    SW.printString("FrameRegister", StringRef("-"));
249    SW.printString("FrameOffset", StringRef("-"));
250  }
251
252  SW.printNumber("UnwindCodeCount", UI.NumCodes);
253  {
254    ListScope UCS(SW, "UnwindCodes");
255    ArrayRef<UnwindCode> UC(&UI.UnwindCodes[0], UI.NumCodes);
256    for (const UnwindCode *UCI = UC.begin(), *UCE = UC.end(); UCI < UCE; ++UCI) {
257      unsigned UsedSlots = getNumUsedSlots(*UCI);
258      if (UsedSlots > UC.size()) {
259        errs() << "corrupt unwind data";
260        return;
261      }
262
263      printUnwindCode(UI, makeArrayRef(UCI, UCE));
264      UCI = UCI + UsedSlots - 1;
265    }
266  }
267
268  uint64_t LSDAOffset = Offset + getOffsetOfLSDA(UI);
269  if (UI.getFlags() & (UNW_ExceptionHandler | UNW_TerminateHandler)) {
270    SW.printString("Handler",
271                   formatSymbol(Ctx, Section, LSDAOffset,
272                                UI.getLanguageSpecificHandlerOffset()));
273  } else if (UI.getFlags() & UNW_ChainInfo) {
274    if (const RuntimeFunction *Chained = UI.getChainedFunctionEntry()) {
275      DictScope CS(SW, "Chained");
276      printRuntimeFunctionEntry(Ctx, Section, LSDAOffset, *Chained);
277    }
278  }
279}
280
281void Dumper::printRuntimeFunction(const Context &Ctx,
282                                  const coff_section *Section,
283                                  uint64_t SectionOffset,
284                                  const RuntimeFunction &RF) {
285  DictScope RFS(SW, "RuntimeFunction");
286  printRuntimeFunctionEntry(Ctx, Section, SectionOffset, RF);
287
288  const coff_section *XData;
289  uint64_t Offset;
290  resolveRelocation(Ctx, Section, SectionOffset + 8, XData, Offset);
291
292  ArrayRef<uint8_t> Contents;
293  error(Ctx.COFF.getSectionContents(XData, Contents));
294  if (Contents.empty())
295    return;
296
297  Offset = Offset + RF.UnwindInfoOffset;
298  if (Offset > Contents.size())
299    return;
300
301  const auto UI = reinterpret_cast<const UnwindInfo*>(Contents.data() + Offset);
302  printUnwindInfo(Ctx, XData, Offset, *UI);
303}
304
305void Dumper::printData(const Context &Ctx) {
306  for (const auto &Section : Ctx.COFF.sections()) {
307    StringRef Name;
308    Section.getName(Name);
309
310    if (Name != ".pdata" && !Name.startswith(".pdata$"))
311      continue;
312
313    const coff_section *PData = Ctx.COFF.getCOFFSection(Section);
314    ArrayRef<uint8_t> Contents;
315    error(Ctx.COFF.getSectionContents(PData, Contents));
316    if (Contents.empty())
317      continue;
318
319    const RuntimeFunction *Entries =
320      reinterpret_cast<const RuntimeFunction *>(Contents.data());
321    const size_t Count = Contents.size() / sizeof(RuntimeFunction);
322    ArrayRef<RuntimeFunction> RuntimeFunctions(Entries, Count);
323
324    size_t Index = 0;
325    for (const auto &RF : RuntimeFunctions) {
326      printRuntimeFunction(Ctx, Ctx.COFF.getCOFFSection(Section),
327                           Index * sizeof(RuntimeFunction), RF);
328      ++Index;
329    }
330  }
331}
332}
333}
334
335