tools/llvm-readobj/Win64EHDumper.cpp

   1 //===- Win64EHDumper.cpp - Win64 EH Printer ---------------------*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "Win64EHDumper.h"
  10 #include "llvm-readobj.h"
  11 #include "llvm/Object/COFF.h"
  12 #include "llvm/Support/ErrorHandling.h"
  13 #include "llvm/Support/Format.h"
  14
  15 using namespace llvm;
  16 using namespace llvm::object;
  17 using namespace llvm::Win64EH;
  18
  19 static const EnumEntry<unsigned> UnwindFlags[] = {
  20   { "ExceptionHandler", UNW_ExceptionHandler },
  21   { "TerminateHandler", UNW_TerminateHandler },
  22   { "ChainInfo"       , UNW_ChainInfo        }
  23 };
  24
  25 static const EnumEntry<unsigned> UnwindOpInfo[] = {
  26   { "RAX",  0 },
  27   { "RCX",  1 },
  28   { "RDX",  2 },
  29   { "RBX",  3 },
  30   { "RSP",  4 },
  31   { "RBP",  5 },
  32   { "RSI",  6 },
  33   { "RDI",  7 },
  34   { "R8",   8 },
  35   { "R9",   9 },
  36   { "R10", 10 },
  37   { "R11", 11 },
  38   { "R12", 12 },
  39   { "R13", 13 },
  40   { "R14", 14 },
  41   { "R15", 15 }
  42 };
  43
  44 static uint64_t getOffsetOfLSDA(const UnwindInfo& UI) {
  45   return static_cast<const char*>(UI.getLanguageSpecificData())
  46          - reinterpret_cast<const char*>(&UI);
  47 }
  48
  49 static uint32_t getLargeSlotValue(ArrayRef<UnwindCode> UC) {
  50   if (UC.size() < 3)
  51     return 0;
  52   return UC[1].FrameOffset + (static_cast<uint32_t>(UC[2].FrameOffset) << 16);
  53 }
  54
  55 // Returns the name of the unwind code.
  56 static StringRef getUnwindCodeTypeName(uint8_t Code) {
  57   switch (Code) {
  58   default: llvm_unreachable("Invalid unwind code");
  59   case UOP_PushNonVol: return "PUSH_NONVOL";
  60   case UOP_AllocLarge: return "ALLOC_LARGE";
  61   case UOP_AllocSmall: return "ALLOC_SMALL";
  62   case UOP_SetFPReg: return "SET_FPREG";
  63   case UOP_SaveNonVol: return "SAVE_NONVOL";
  64   case UOP_SaveNonVolBig: return "SAVE_NONVOL_FAR";
  65   case UOP_SaveXMM128: return "SAVE_XMM128";
  66   case UOP_SaveXMM128Big: return "SAVE_XMM128_FAR";
  67   case UOP_PushMachFrame: return "PUSH_MACHFRAME";
  68   }
  69 }
  70
  71 // Returns the name of a referenced register.
  72 static StringRef getUnwindRegisterName(uint8_t Reg) {
  73   switch (Reg) {
  74   default: llvm_unreachable("Invalid register");
  75   case 0: return "RAX";
  76   case 1: return "RCX";
  77   case 2: return "RDX";
  78   case 3: return "RBX";
  79   case 4: return "RSP";
  80   case 5: return "RBP";
  81   case 6: return "RSI";
  82   case 7: return "RDI";
  83   case 8: return "R8";
  84   case 9: return "R9";
  85   case 10: return "R10";
  86   case 11: return "R11";
  87   case 12: return "R12";
  88   case 13: return "R13";
  89   case 14: return "R14";
  90   case 15: return "R15";
  91   }
  92 }
  93
  94 // Calculates the number of array slots required for the unwind code.
  95 static unsigned getNumUsedSlots(const UnwindCode &UnwindCode) {
  96   switch (UnwindCode.getUnwindOp()) {
  97   default: llvm_unreachable("Invalid unwind code");
  98   case UOP_PushNonVol:
  99   case UOP_AllocSmall:
 100   case UOP_SetFPReg:
 101   case UOP_PushMachFrame:
 102     return 1;
 103   case UOP_SaveNonVol:
 104   case UOP_SaveXMM128:
 105     return 2;
 106   case UOP_SaveNonVolBig:
 107   case UOP_SaveXMM128Big:
 108     return 3;
 109   case UOP_AllocLarge:
 110     return (UnwindCode.getOpInfo() == 0) ? 2 : 3;
 111   }
 112 }
 113
 114 static std::string formatSymbol(const Dumper::Context &Ctx,
 115                                 const coff_section *Section, uint64_t Offset,
 116                                 uint32_t Displacement) {
 117   std::string Buffer;
 118   raw_string_ostream OS(Buffer);
 119
 120   SymbolRef Symbol;
 121   if (!Ctx.ResolveSymbol(Section, Offset, Symbol, Ctx.UserData)) {
 122     Expected<StringRef> Name = Symbol.getName();
 123     if (Name) {
 124       OS << *Name;
 125       if (Displacement > 0)
 126         OS << format(" +0x%X (0x%" PRIX64 ")", Displacement, Offset);
 127       else
 128         OS << format(" (0x%" PRIX64 ")", Offset);
 129       return OS.str();
 130     } else {
 131       // TODO: Actually report errors helpfully.
 132       consumeError(Name.takeError());
 133     }
 134   }
 135
 136   OS << format(" (0x%" PRIX64 ")", Offset);
 137   return OS.str();
 138 }
 139
 140 static std::error_code resolveRelocation(const Dumper::Context &Ctx,
 141                                          const coff_section *Section,
 142                                          uint64_t Offset,
 143                                          const coff_section *&ResolvedSection,
 144                                          uint64_t &ResolvedAddress) {
 145   SymbolRef Symbol;
 146   if (std::error_code EC =
 147           Ctx.ResolveSymbol(Section, Offset, Symbol, Ctx.UserData))
 148     return EC;
 149
 150   Expected<uint64_t> ResolvedAddressOrErr = Symbol.getAddress();
 151   if (!ResolvedAddressOrErr)
 152     return errorToErrorCode(ResolvedAddressOrErr.takeError());
 153   ResolvedAddress = *ResolvedAddressOrErr;
 154
 155   Expected<section_iterator> SI = Symbol.getSection();
 156   if (!SI)
 157     return errorToErrorCode(SI.takeError());
 158   ResolvedSection = Ctx.COFF.getCOFFSection(**SI);
 159   return std::error_code();
 160 }
 161
 162 namespace llvm {
 163 namespace Win64EH {
 164 void Dumper::printRuntimeFunctionEntry(const Context &Ctx,
 165                                        const coff_section *Section,
 166                                        uint64_t Offset,
 167                                        const RuntimeFunction &RF) {
 168   SW.printString("StartAddress",
 169                  formatSymbol(Ctx, Section, Offset + 0, RF.StartAddress));
 170   SW.printString("EndAddress",
 171                  formatSymbol(Ctx, Section, Offset + 4, RF.EndAddress));
 172   SW.printString("UnwindInfoAddress",
 173                  formatSymbol(Ctx, Section, Offset + 8, RF.UnwindInfoOffset));
 174 }
 175
 176 // Prints one unwind code. Because an unwind code can occupy up to 3 slots in
 177 // the unwind codes array, this function requires that the correct number of
 178 // slots is provided.
 179 void Dumper::printUnwindCode(const UnwindInfo& UI, ArrayRef<UnwindCode> UC) {
 180   assert(UC.size() >= getNumUsedSlots(UC[0]));
 181
 182   SW.startLine() << format("0x%02X: ", unsigned(UC[0].u.CodeOffset))
 183                  << getUnwindCodeTypeName(UC[0].getUnwindOp());
 184
 185   switch (UC[0].getUnwindOp()) {
 186   case UOP_PushNonVol:
 187     OS << " reg=" << getUnwindRegisterName(UC[0].getOpInfo());
 188     break;
 189
 190   case UOP_AllocLarge:
 191     OS << " size="
 192        << ((UC[0].getOpInfo() == 0) ? UC[1].FrameOffset * 8
 193                                     : getLargeSlotValue(UC));
 194     break;
 195
 196   case UOP_AllocSmall:
 197     OS << " size=" << (UC[0].getOpInfo() + 1) * 8;
 198     break;
 199
 200   case UOP_SetFPReg:
 201     if (UI.getFrameRegister() == 0)
 202       OS << " reg=<invalid>";
 203     else
 204       OS << " reg=" << getUnwindRegisterName(UI.getFrameRegister())
 205          << format(", offset=0x%X", UI.getFrameOffset() * 16);
 206     break;
 207
 208   case UOP_SaveNonVol:
 209     OS << " reg=" << getUnwindRegisterName(UC[0].getOpInfo())
 210        << format(", offset=0x%X", UC[1].FrameOffset * 8);
 211     break;
 212
 213   case UOP_SaveNonVolBig:
 214     OS << " reg=" << getUnwindRegisterName(UC[0].getOpInfo())
 215        << format(", offset=0x%X", getLargeSlotValue(UC));
 216     break;
 217
 218   case UOP_SaveXMM128:
 219     OS << " reg=XMM" << static_cast<uint32_t>(UC[0].getOpInfo())
 220        << format(", offset=0x%X", UC[1].FrameOffset * 16);
 221     break;
 222
 223   case UOP_SaveXMM128Big:
 224     OS << " reg=XMM" << static_cast<uint32_t>(UC[0].getOpInfo())
 225        << format(", offset=0x%X", getLargeSlotValue(UC));
 226     break;
 227
 228   case UOP_PushMachFrame:
 229     OS << " errcode=" << (UC[0].getOpInfo() == 0 ? "no" : "yes");
 230     break;
 231   }
 232
 233   OS << "\n";
 234 }
 235
 236 void Dumper::printUnwindInfo(const Context &Ctx, const coff_section *Section,
 237                              off_t Offset, const UnwindInfo &UI) {
 238   DictScope UIS(SW, "UnwindInfo");
 239   SW.printNumber("Version", UI.getVersion());
 240   SW.printFlags("Flags", UI.getFlags(), makeArrayRef(UnwindFlags));
 241   SW.printNumber("PrologSize", UI.PrologSize);
 242   if (UI.getFrameRegister()) {
 243     SW.printEnum("FrameRegister", UI.getFrameRegister(),
 244                  makeArrayRef(UnwindOpInfo));
 245     SW.printHex("FrameOffset", UI.getFrameOffset());
 246   } else {
 247     SW.printString("FrameRegister", StringRef("-"));
 248     SW.printString("FrameOffset", StringRef("-"));
 249   }
 250
 251   SW.printNumber("UnwindCodeCount", UI.NumCodes);
 252   {
 253     ListScope UCS(SW, "UnwindCodes");
 254     ArrayRef<UnwindCode> UC(&UI.UnwindCodes[0], UI.NumCodes);
 255     for (const UnwindCode *UCI = UC.begin(), *UCE = UC.end(); UCI < UCE; ++UCI) {
 256       unsigned UsedSlots = getNumUsedSlots(*UCI);
 257       if (UsedSlots > UC.size()) {
 258         errs() << "corrupt unwind data";
 259         return;
 260       }
 261
 262       printUnwindCode(UI, makeArrayRef(UCI, UCE));
 263       UCI = UCI + UsedSlots - 1;
 264     }
 265   }
 266
 267   uint64_t LSDAOffset = Offset + getOffsetOfLSDA(UI);
 268   if (UI.getFlags() & (UNW_ExceptionHandler | UNW_TerminateHandler)) {
 269     SW.printString("Handler",
 270                    formatSymbol(Ctx, Section, LSDAOffset,
 271                                 UI.getLanguageSpecificHandlerOffset()));
 272   } else if (UI.getFlags() & UNW_ChainInfo) {
 273     if (const RuntimeFunction *Chained = UI.getChainedFunctionEntry()) {
 274       DictScope CS(SW, "Chained");
 275       printRuntimeFunctionEntry(Ctx, Section, LSDAOffset, *Chained);
 276     }
 277   }
 278 }
 279
 280 void Dumper::printRuntimeFunction(const Context &Ctx,
 281                                   const coff_section *Section,
 282                                   uint64_t SectionOffset,
 283                                   const RuntimeFunction &RF) {
 284   DictScope RFS(SW, "RuntimeFunction");
 285   printRuntimeFunctionEntry(Ctx, Section, SectionOffset, RF);
 286
 287   const coff_section *XData;
 288   uint64_t Offset;
 289   resolveRelocation(Ctx, Section, SectionOffset + 8, XData, Offset);
 290
 291   ArrayRef<uint8_t> Contents;
 292   if (Error E = Ctx.COFF.getSectionContents(XData, Contents))
 293     reportError(std::move(E), Ctx.COFF.getFileName());
 294
 295   if (Contents.empty())
 296     return;
 297
 298   Offset = Offset + RF.UnwindInfoOffset;
 299   if (Offset > Contents.size())
 300     return;
 301
 302   const auto UI = reinterpret_cast<const UnwindInfo*>(Contents.data() + Offset);
 303   printUnwindInfo(Ctx, XData, Offset, *UI);
 304 }
 305
 306 void Dumper::printData(const Context &Ctx) {
 307   for (const auto &Section : Ctx.COFF.sections()) {
 308     StringRef Name;
 309     if (Expected<StringRef> NameOrErr = Section.getName())
 310       Name = *NameOrErr;
 311     else
 312       consumeError(NameOrErr.takeError());
 313
 314     if (Name != ".pdata" && !Name.startswith(".pdata$"))
 315       continue;
 316
 317     const coff_section *PData = Ctx.COFF.getCOFFSection(Section);
 318     ArrayRef<uint8_t> Contents;
 319
 320     if (Error E = Ctx.COFF.getSectionContents(PData, Contents))
 321       reportError(std::move(E), Ctx.COFF.getFileName());
 322     if (Contents.empty())
 323       continue;
 324
 325     const RuntimeFunction *Entries =
 326       reinterpret_cast<const RuntimeFunction *>(Contents.data());
 327     const size_t Count = Contents.size() / sizeof(RuntimeFunction);
 328     ArrayRef<RuntimeFunction> RuntimeFunctions(Entries, Count);
 329
 330     size_t Index = 0;
 331     for (const auto &RF : RuntimeFunctions) {
 332       printRuntimeFunction(Ctx, Ctx.COFF.getCOFFSection(Section),
 333                            Index * sizeof(RuntimeFunction), RF);
 334       ++Index;
 335     }
 336   }
 337 }
 338 }
 339 }
 340