tools/llvm-readobj/Win64EHDumper.cpp

   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
  16 using namespace llvm;
  17 using namespace llvm::object;
  18 using namespace llvm::Win64EH;
  19
  20 static const EnumEntry<unsigned> UnwindFlags[] = {
  21   { "ExceptionHandler", UNW_ExceptionHandler },
  22   { "TerminateHandler", UNW_TerminateHandler },
  23   { "ChainInfo"       , UNW_ChainInfo        }
  24 };
  25
  26 static 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
  45 static uint64_t getOffsetOfLSDA(const UnwindInfo& UI) {
  46   return static_cast<const char*>(UI.getLanguageSpecificData())
  47          - reinterpret_cast<const char*>(&UI);
  48 }
  49
  50 static 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.
  57 static 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.
  73 static 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.
  96 static 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
 115 static 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
 141 static 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
 163 namespace llvm {
 164 namespace Win64EH {
 165 void 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.
 180 void 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
 237 void 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
 281 void 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
 305 void 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