Win64EHDumper.cpp revision dce4a407a24b04eebc6a376f8e62b41aaa7b071f 
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  StringRef Name;
122  SymbolRef Symbol;
123  if (Ctx.ResolveSymbol(Section, Offset, Symbol, Ctx.UserData) ||
124      Symbol.getName(Name)) {
125    OS << format(" (0x%" PRIX64 ")", Offset);
126    return OS.str();
127  }
128
129  OS << Name;
130  if (Displacement > 0)
131    OS << format(" +0x%X (0x%" PRIX64 ")", Displacement, Offset);
132  else
133    OS << format(" (0x%" PRIX64 ")", Offset);
134  return OS.str();
135}
136
137static error_code resolveRelocation(const Dumper::Context &Ctx,
138                                    const coff_section *Section,
139                                    uint64_t Offset,
140                                    const coff_section *&ResolvedSection,
141                                    uint64_t &ResolvedAddress) {
142  SymbolRef Symbol;
143  if (error_code EC = Ctx.ResolveSymbol(Section, Offset, Symbol, Ctx.UserData))
144    return EC;
145
146  if (error_code EC = Symbol.getAddress(ResolvedAddress))
147    return EC;
148
149  section_iterator SI = Ctx.COFF.section_begin();
150  if (error_code EC = Symbol.getSection(SI))
151    return EC;
152
153  ResolvedSection = Ctx.COFF.getCOFFSection(*SI);
154  return object_error::success;
155}
156
157namespace llvm {
158namespace Win64EH {
159void Dumper::printRuntimeFunctionEntry(const Context &Ctx,
160                                       const coff_section *Section,
161                                       uint64_t Offset,
162                                       const RuntimeFunction &RF) {
163  SW.printString("StartAddress",
164                 formatSymbol(Ctx, Section, Offset + 0, RF.StartAddress));
165  SW.printString("EndAddress",
166                 formatSymbol(Ctx, Section, Offset + 4, RF.EndAddress));
167  SW.printString("UnwindInfoAddress",
168                 formatSymbol(Ctx, Section, Offset + 8, RF.UnwindInfoOffset));
169}
170
171// Prints one unwind code. Because an unwind code can occupy up to 3 slots in
172// the unwind codes array, this function requires that the correct number of
173// slots is provided.
174void Dumper::printUnwindCode(const UnwindInfo& UI, ArrayRef<UnwindCode> UC) {
175  assert(UC.size() >= getNumUsedSlots(UC[0]));
176
177  SW.startLine() << format("0x%02X: ", unsigned(UC[0].u.CodeOffset))
178                 << getUnwindCodeTypeName(UC[0].getUnwindOp());
179
180  switch (UC[0].getUnwindOp()) {
181  case UOP_PushNonVol:
182    OS << " reg=" << getUnwindRegisterName(UC[0].getOpInfo());
183    break;
184
185  case UOP_AllocLarge:
186    OS << " size="
187       << ((UC[0].getOpInfo() == 0) ? UC[1].FrameOffset * 8
188                                    : getLargeSlotValue(UC));
189    break;
190
191  case UOP_AllocSmall:
192    OS << " size=" << (UC[0].getOpInfo() + 1) * 8;
193    break;
194
195  case UOP_SetFPReg:
196    if (UI.getFrameRegister() == 0)
197      OS << " reg=<invalid>";
198    else
199      OS << " reg=" << getUnwindRegisterName(UI.getFrameRegister())
200         << format(", offset=0x%X", UI.getFrameOffset() * 16);
201    break;
202
203  case UOP_SaveNonVol:
204    OS << " reg=" << getUnwindRegisterName(UC[0].getOpInfo())
205       << format(", offset=0x%X", UC[1].FrameOffset * 8);
206    break;
207
208  case UOP_SaveNonVolBig:
209    OS << " reg=" << getUnwindRegisterName(UC[0].getOpInfo())
210       << format(", offset=0x%X", getLargeSlotValue(UC));
211    break;
212
213  case UOP_SaveXMM128:
214    OS << " reg=XMM" << static_cast<uint32_t>(UC[0].getOpInfo())
215       << format(", offset=0x%X", UC[1].FrameOffset * 16);
216    break;
217
218  case UOP_SaveXMM128Big:
219    OS << " reg=XMM" << static_cast<uint32_t>(UC[0].getOpInfo())
220       << format(", offset=0x%X", getLargeSlotValue(UC));
221    break;
222
223  case UOP_PushMachFrame:
224    OS << " errcode=" << (UC[0].getOpInfo() == 0 ? "no" : "yes");
225    break;
226  }
227
228  OS << "\n";
229}
230
231void Dumper::printUnwindInfo(const Context &Ctx, const coff_section *Section,
232                             off_t Offset, const UnwindInfo &UI) {
233  DictScope UIS(SW, "UnwindInfo");
234  SW.printNumber("Version", UI.getVersion());
235  SW.printFlags("Flags", UI.getFlags(), makeArrayRef(UnwindFlags));
236  SW.printNumber("PrologSize", UI.PrologSize);
237  if (UI.getFrameRegister()) {
238    SW.printEnum("FrameRegister", UI.getFrameRegister(),
239                 makeArrayRef(UnwindOpInfo));
240    SW.printHex("FrameOffset", UI.getFrameOffset());
241  } else {
242    SW.printString("FrameRegister", StringRef("-"));
243    SW.printString("FrameOffset", StringRef("-"));
244  }
245
246  SW.printNumber("UnwindCodeCount", UI.NumCodes);
247  {
248    ListScope UCS(SW, "UnwindCodes");
249    ArrayRef<UnwindCode> UC(&UI.UnwindCodes[0], UI.NumCodes);
250    for (const UnwindCode *UCI = UC.begin(), *UCE = UC.end(); UCI < UCE; ++UCI) {
251      unsigned UsedSlots = getNumUsedSlots(*UCI);
252      if (UsedSlots > UC.size()) {
253        errs() << "corrupt unwind data";
254        return;
255      }
256
257      printUnwindCode(UI, ArrayRef<UnwindCode>(UCI, UCE));
258      UCI = UCI + UsedSlots - 1;
259    }
260  }
261
262  uint64_t LSDAOffset = Offset + getOffsetOfLSDA(UI);
263  if (UI.getFlags() & (UNW_ExceptionHandler | UNW_TerminateHandler)) {
264    SW.printString("Handler",
265                   formatSymbol(Ctx, Section, LSDAOffset,
266                                UI.getLanguageSpecificHandlerOffset()));
267  } else if (UI.getFlags() & UNW_ChainInfo) {
268    if (const RuntimeFunction *Chained = UI.getChainedFunctionEntry()) {
269      DictScope CS(SW, "Chained");
270      printRuntimeFunctionEntry(Ctx, Section, LSDAOffset, *Chained);
271    }
272  }
273}
274
275void Dumper::printRuntimeFunction(const Context &Ctx,
276                                  const coff_section *Section,
277                                  uint64_t SectionOffset,
278                                  const RuntimeFunction &RF) {
279  DictScope RFS(SW, "RuntimeFunction");
280  printRuntimeFunctionEntry(Ctx, Section, SectionOffset, RF);
281
282  const coff_section *XData;
283  uint64_t Offset;
284  if (error(resolveRelocation(Ctx, Section, SectionOffset + 8, XData, Offset)))
285    return;
286
287  ArrayRef<uint8_t> Contents;
288  if (error(Ctx.COFF.getSectionContents(XData, Contents)) || Contents.empty())
289    return;
290
291  Offset = Offset + RF.UnwindInfoOffset;
292  if (Offset > Contents.size())
293    return;
294
295  const auto UI = reinterpret_cast<const UnwindInfo*>(Contents.data() + Offset);
296  printUnwindInfo(Ctx, XData, Offset, *UI);
297}
298
299void Dumper::printData(const Context &Ctx) {
300  for (const auto &Section : Ctx.COFF.sections()) {
301    StringRef Name;
302    if (error(Section.getName(Name)))
303      continue;
304
305    if (Name != ".pdata" && !Name.startswith(".pdata$"))
306      continue;
307
308    const coff_section *PData = Ctx.COFF.getCOFFSection(Section);
309    ArrayRef<uint8_t> Contents;
310    if (error(Ctx.COFF.getSectionContents(PData, Contents)) || Contents.empty())
311      continue;
312
313    const RuntimeFunction *Entries =
314      reinterpret_cast<const RuntimeFunction *>(Contents.data());
315    const size_t Count = Contents.size() / sizeof(RuntimeFunction);
316    ArrayRef<RuntimeFunction> RuntimeFunctions(Entries, Count);
317
318    size_t Index = 0;
319    for (const auto &RF : RuntimeFunctions) {
320      printRuntimeFunction(Ctx, Ctx.COFF.getCOFFSection(Section),
321                           Index * sizeof(RuntimeFunction), RF);
322      ++Index;
323    }
324  }
325}
326}
327}
328
329