lib/ObjectYAML/DWARFEmitter.cpp

   1 //===- DWARFEmitter - Convert YAML to DWARF binary data -------------------===//
   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 /// \file
  11 /// The DWARF component of yaml2obj. Provided as library code for tests.
  12 ///
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "llvm/ObjectYAML/DWARFEmitter.h"
  16 #include "DWARFVisitor.h"
  17 #include "llvm/ADT/StringMap.h"
  18 #include "llvm/ADT/StringRef.h"
  19 #include "llvm/ObjectYAML/DWARFYAML.h"
  20 #include "llvm/Support/Error.h"
  21 #include "llvm/Support/Host.h"
  22 #include "llvm/Support/LEB128.h"
  23 #include "llvm/Support/MathExtras.h"
  24 #include "llvm/Support/MemoryBuffer.h"
  25 #include "llvm/Support/SwapByteOrder.h"
  26 #include "llvm/Support/YAMLTraits.h"
  27 #include "llvm/Support/raw_ostream.h"
  28 #include <algorithm>
  29 #include <cassert>
  30 #include <cstddef>
  31 #include <cstdint>
  32 #include <memory>
  33 #include <string>
  34 #include <vector>
  35
  36 using namespace llvm;
  37
  38 template <typename T>
  39 static void writeInteger(T Integer, raw_ostream &OS, bool IsLittleEndian) {
  40   if (IsLittleEndian != sys::IsLittleEndianHost)
  41     sys::swapByteOrder(Integer);
  42   OS.write(reinterpret_cast<char *>(&Integer), sizeof(T));
  43 }
  44
  45 static void writeVariableSizedInteger(uint64_t Integer, size_t Size,
  46                                       raw_ostream &OS, bool IsLittleEndian) {
  47   if (8 == Size)
  48     writeInteger((uint64_t)Integer, OS, IsLittleEndian);
  49   else if (4 == Size)
  50     writeInteger((uint32_t)Integer, OS, IsLittleEndian);
  51   else if (2 == Size)
  52     writeInteger((uint16_t)Integer, OS, IsLittleEndian);
  53   else if (1 == Size)
  54     writeInteger((uint8_t)Integer, OS, IsLittleEndian);
  55   else
  56     assert(false && "Invalid integer write size.");
  57 }
  58
  59 static void ZeroFillBytes(raw_ostream &OS, size_t Size) {
  60   std::vector<uint8_t> FillData;
  61   FillData.insert(FillData.begin(), Size, 0);
  62   OS.write(reinterpret_cast<char *>(FillData.data()), Size);
  63 }
  64
  65 static void writeInitialLength(const DWARFYAML::InitialLength &Length,
  66                                raw_ostream &OS, bool IsLittleEndian) {
  67   writeInteger((uint32_t)Length.TotalLength, OS, IsLittleEndian);
  68   if (Length.isDWARF64())
  69     writeInteger((uint64_t)Length.TotalLength64, OS, IsLittleEndian);
  70 }
  71
  72 void DWARFYAML::EmitDebugStr(raw_ostream &OS, const DWARFYAML::Data &DI) {
  73   for (auto Str : DI.DebugStrings) {
  74     OS.write(Str.data(), Str.size());
  75     OS.write('\0');
  76   }
  77 }
  78
  79 void DWARFYAML::EmitDebugAbbrev(raw_ostream &OS, const DWARFYAML::Data &DI) {
  80   for (auto AbbrevDecl : DI.AbbrevDecls) {
  81     encodeULEB128(AbbrevDecl.Code, OS);
  82     encodeULEB128(AbbrevDecl.Tag, OS);
  83     OS.write(AbbrevDecl.Children);
  84     for (auto Attr : AbbrevDecl.Attributes) {
  85       encodeULEB128(Attr.Attribute, OS);
  86       encodeULEB128(Attr.Form, OS);
  87       if (Attr.Form == dwarf::DW_FORM_implicit_const)
  88         encodeSLEB128(Attr.Value, OS);
  89     }
  90     encodeULEB128(0, OS);
  91     encodeULEB128(0, OS);
  92   }
  93 }
  94
  95 void DWARFYAML::EmitDebugAranges(raw_ostream &OS, const DWARFYAML::Data &DI) {
  96   for (auto Range : DI.ARanges) {
  97     auto HeaderStart = OS.tell();
  98     writeInitialLength(Range.Length, OS, DI.IsLittleEndian);
  99     writeInteger((uint16_t)Range.Version, OS, DI.IsLittleEndian);
 100     writeInteger((uint32_t)Range.CuOffset, OS, DI.IsLittleEndian);
 101     writeInteger((uint8_t)Range.AddrSize, OS, DI.IsLittleEndian);
 102     writeInteger((uint8_t)Range.SegSize, OS, DI.IsLittleEndian);
 103
 104     auto HeaderSize = OS.tell() - HeaderStart;
 105     auto FirstDescriptor = alignTo(HeaderSize, Range.AddrSize * 2);
 106     ZeroFillBytes(OS, FirstDescriptor - HeaderSize);
 107
 108     for (auto Descriptor : Range.Descriptors) {
 109       writeVariableSizedInteger(Descriptor.Address, Range.AddrSize, OS,
 110                                 DI.IsLittleEndian);
 111       writeVariableSizedInteger(Descriptor.Length, Range.AddrSize, OS,
 112                                 DI.IsLittleEndian);
 113     }
 114     ZeroFillBytes(OS, Range.AddrSize * 2);
 115   }
 116 }
 117
 118 void DWARFYAML::EmitPubSection(raw_ostream &OS,
 119                                const DWARFYAML::PubSection &Sect,
 120                                bool IsLittleEndian) {
 121   writeInitialLength(Sect.Length, OS, IsLittleEndian);
 122   writeInteger((uint16_t)Sect.Version, OS, IsLittleEndian);
 123   writeInteger((uint32_t)Sect.UnitOffset, OS, IsLittleEndian);
 124   writeInteger((uint32_t)Sect.UnitSize, OS, IsLittleEndian);
 125   for (auto Entry : Sect.Entries) {
 126     writeInteger((uint32_t)Entry.DieOffset, OS, IsLittleEndian);
 127     if (Sect.IsGNUStyle)
 128       writeInteger((uint32_t)Entry.Descriptor, OS, IsLittleEndian);
 129     OS.write(Entry.Name.data(), Entry.Name.size());
 130     OS.write('\0');
 131   }
 132 }
 133
 134 namespace {
 135 /// An extension of the DWARFYAML::ConstVisitor which writes compile
 136 /// units and DIEs to a stream.
 137 class DumpVisitor : public DWARFYAML::ConstVisitor {
 138   raw_ostream &OS;
 139
 140 protected:
 141   void onStartCompileUnit(const DWARFYAML::Unit &CU) override {
 142     writeInitialLength(CU.Length, OS, DebugInfo.IsLittleEndian);
 143     writeInteger((uint16_t)CU.Version, OS, DebugInfo.IsLittleEndian);
 144     if(CU.Version >= 5) {
 145       writeInteger((uint8_t)CU.Type, OS, DebugInfo.IsLittleEndian);
 146       writeInteger((uint8_t)CU.AddrSize, OS, DebugInfo.IsLittleEndian);
 147       writeInteger((uint32_t)CU.AbbrOffset, OS, DebugInfo.IsLittleEndian);
 148     }else {
 149       writeInteger((uint32_t)CU.AbbrOffset, OS, DebugInfo.IsLittleEndian);
 150       writeInteger((uint8_t)CU.AddrSize, OS, DebugInfo.IsLittleEndian);
 151     }
 152   }
 153
 154   void onStartDIE(const DWARFYAML::Unit &CU,
 155                   const DWARFYAML::Entry &DIE) override {
 156     encodeULEB128(DIE.AbbrCode, OS);
 157   }
 158
 159   void onValue(const uint8_t U) override {
 160     writeInteger(U, OS, DebugInfo.IsLittleEndian);
 161   }
 162
 163   void onValue(const uint16_t U) override {
 164     writeInteger(U, OS, DebugInfo.IsLittleEndian);
 165   }
 166
 167   void onValue(const uint32_t U) override {
 168     writeInteger(U, OS, DebugInfo.IsLittleEndian);
 169   }
 170
 171   void onValue(const uint64_t U, const bool LEB = false) override {
 172     if (LEB)
 173       encodeULEB128(U, OS);
 174     else
 175       writeInteger(U, OS, DebugInfo.IsLittleEndian);
 176   }
 177
 178   void onValue(const int64_t S, const bool LEB = false) override {
 179     if (LEB)
 180       encodeSLEB128(S, OS);
 181     else
 182       writeInteger(S, OS, DebugInfo.IsLittleEndian);
 183   }
 184
 185   void onValue(const StringRef String) override {
 186     OS.write(String.data(), String.size());
 187     OS.write('\0');
 188   }
 189
 190   void onValue(const MemoryBufferRef MBR) override {
 191     OS.write(MBR.getBufferStart(), MBR.getBufferSize());
 192   }
 193
 194 public:
 195   DumpVisitor(const DWARFYAML::Data &DI, raw_ostream &Out)
 196       : DWARFYAML::ConstVisitor(DI), OS(Out) {}
 197 };
 198 } // namespace
 199
 200 void DWARFYAML::EmitDebugInfo(raw_ostream &OS, const DWARFYAML::Data &DI) {
 201   DumpVisitor Visitor(DI, OS);
 202   Visitor.traverseDebugInfo();
 203 }
 204
 205 static void EmitFileEntry(raw_ostream &OS, const DWARFYAML::File &File) {
 206   OS.write(File.Name.data(), File.Name.size());
 207   OS.write('\0');
 208   encodeULEB128(File.DirIdx, OS);
 209   encodeULEB128(File.ModTime, OS);
 210   encodeULEB128(File.Length, OS);
 211 }
 212
 213 void DWARFYAML::EmitDebugLine(raw_ostream &OS, const DWARFYAML::Data &DI) {
 214   for (const auto &LineTable : DI.DebugLines) {
 215     writeInitialLength(LineTable.Length, OS, DI.IsLittleEndian);
 216     uint64_t SizeOfPrologueLength = LineTable.Length.isDWARF64() ? 8 : 4;
 217     writeInteger((uint16_t)LineTable.Version, OS, DI.IsLittleEndian);
 218     writeVariableSizedInteger(LineTable.PrologueLength, SizeOfPrologueLength,
 219                               OS, DI.IsLittleEndian);
 220     writeInteger((uint8_t)LineTable.MinInstLength, OS, DI.IsLittleEndian);
 221     if (LineTable.Version >= 4)
 222       writeInteger((uint8_t)LineTable.MaxOpsPerInst, OS, DI.IsLittleEndian);
 223     writeInteger((uint8_t)LineTable.DefaultIsStmt, OS, DI.IsLittleEndian);
 224     writeInteger((uint8_t)LineTable.LineBase, OS, DI.IsLittleEndian);
 225     writeInteger((uint8_t)LineTable.LineRange, OS, DI.IsLittleEndian);
 226     writeInteger((uint8_t)LineTable.OpcodeBase, OS, DI.IsLittleEndian);
 227
 228     for (auto OpcodeLength : LineTable.StandardOpcodeLengths)
 229       writeInteger((uint8_t)OpcodeLength, OS, DI.IsLittleEndian);
 230
 231     for (auto IncludeDir : LineTable.IncludeDirs) {
 232       OS.write(IncludeDir.data(), IncludeDir.size());
 233       OS.write('\0');
 234     }
 235     OS.write('\0');
 236
 237     for (auto File : LineTable.Files)
 238       EmitFileEntry(OS, File);
 239     OS.write('\0');
 240
 241     for (auto Op : LineTable.Opcodes) {
 242       writeInteger((uint8_t)Op.Opcode, OS, DI.IsLittleEndian);
 243       if (Op.Opcode == 0) {
 244         encodeULEB128(Op.ExtLen, OS);
 245         writeInteger((uint8_t)Op.SubOpcode, OS, DI.IsLittleEndian);
 246         switch (Op.SubOpcode) {
 247         case dwarf::DW_LNE_set_address:
 248         case dwarf::DW_LNE_set_discriminator:
 249           writeVariableSizedInteger(Op.Data, DI.CompileUnits[0].AddrSize, OS,
 250                                     DI.IsLittleEndian);
 251           break;
 252         case dwarf::DW_LNE_define_file:
 253           EmitFileEntry(OS, Op.FileEntry);
 254           break;
 255         case dwarf::DW_LNE_end_sequence:
 256           break;
 257         default:
 258           for (auto OpByte : Op.UnknownOpcodeData)
 259             writeInteger((uint8_t)OpByte, OS, DI.IsLittleEndian);
 260         }
 261       } else if (Op.Opcode < LineTable.OpcodeBase) {
 262         switch (Op.Opcode) {
 263         case dwarf::DW_LNS_copy:
 264         case dwarf::DW_LNS_negate_stmt:
 265         case dwarf::DW_LNS_set_basic_block:
 266         case dwarf::DW_LNS_const_add_pc:
 267         case dwarf::DW_LNS_set_prologue_end:
 268         case dwarf::DW_LNS_set_epilogue_begin:
 269           break;
 270
 271         case dwarf::DW_LNS_advance_pc:
 272         case dwarf::DW_LNS_set_file:
 273         case dwarf::DW_LNS_set_column:
 274         case dwarf::DW_LNS_set_isa:
 275           encodeULEB128(Op.Data, OS);
 276           break;
 277
 278         case dwarf::DW_LNS_advance_line:
 279           encodeSLEB128(Op.SData, OS);
 280           break;
 281
 282         case dwarf::DW_LNS_fixed_advance_pc:
 283           writeInteger((uint16_t)Op.Data, OS, DI.IsLittleEndian);
 284           break;
 285
 286         default:
 287           for (auto OpData : Op.StandardOpcodeData) {
 288             encodeULEB128(OpData, OS);
 289           }
 290         }
 291       }
 292     }
 293   }
 294 }
 295
 296 using EmitFuncType = void (*)(raw_ostream &, const DWARFYAML::Data &);
 297
 298 static void
 299 EmitDebugSectionImpl(const DWARFYAML::Data &DI, EmitFuncType EmitFunc,
 300                      StringRef Sec,
 301                      StringMap<std::unique_ptr<MemoryBuffer>> &OutputBuffers) {
 302   std::string Data;
 303   raw_string_ostream DebugInfoStream(Data);
 304   EmitFunc(DebugInfoStream, DI);
 305   DebugInfoStream.flush();
 306   if (!Data.empty())
 307     OutputBuffers[Sec] = MemoryBuffer::getMemBufferCopy(Data);
 308 }
 309
 310 namespace {
 311 class DIEFixupVisitor : public DWARFYAML::Visitor {
 312   uint64_t Length;
 313
 314 public:
 315   DIEFixupVisitor(DWARFYAML::Data &DI) : DWARFYAML::Visitor(DI){};
 316
 317 private:
 318   virtual void onStartCompileUnit(DWARFYAML::Unit &CU) { Length = 7; }
 319
 320   virtual void onEndCompileUnit(DWARFYAML::Unit &CU) {
 321     CU.Length.setLength(Length);
 322   }
 323
 324   virtual void onStartDIE(DWARFYAML::Unit &CU, DWARFYAML::Entry &DIE) {
 325     Length += getULEB128Size(DIE.AbbrCode);
 326   }
 327
 328   virtual void onValue(const uint8_t U) { Length += 1; }
 329   virtual void onValue(const uint16_t U) { Length += 2; }
 330   virtual void onValue(const uint32_t U) { Length += 4; }
 331   virtual void onValue(const uint64_t U, const bool LEB = false) {
 332     if (LEB)
 333       Length += getULEB128Size(U);
 334     else
 335       Length += 8;
 336   }
 337   virtual void onValue(const int64_t S, const bool LEB = false) {
 338     if (LEB)
 339       Length += getSLEB128Size(S);
 340     else
 341       Length += 8;
 342   }
 343   virtual void onValue(const StringRef String) { Length += String.size() + 1; }
 344
 345   virtual void onValue(const MemoryBufferRef MBR) {
 346     Length += MBR.getBufferSize();
 347   }
 348 };
 349 } // namespace
 350
 351 Expected<StringMap<std::unique_ptr<MemoryBuffer>>>
 352 DWARFYAML::EmitDebugSections(StringRef YAMLString, bool ApplyFixups,
 353                              bool IsLittleEndian) {
 354   yaml::Input YIn(YAMLString);
 355
 356   DWARFYAML::Data DI;
 357   DI.IsLittleEndian = IsLittleEndian;
 358   YIn >> DI;
 359   if (YIn.error())
 360     return errorCodeToError(YIn.error());
 361
 362   if (ApplyFixups) {
 363     DIEFixupVisitor DIFixer(DI);
 364     DIFixer.traverseDebugInfo();
 365   }
 366
 367   StringMap<std::unique_ptr<MemoryBuffer>> DebugSections;
 368   EmitDebugSectionImpl(DI, &DWARFYAML::EmitDebugInfo, "debug_info",
 369                        DebugSections);
 370   EmitDebugSectionImpl(DI, &DWARFYAML::EmitDebugLine, "debug_line",
 371                        DebugSections);
 372   EmitDebugSectionImpl(DI, &DWARFYAML::EmitDebugStr, "debug_str",
 373                        DebugSections);
 374   EmitDebugSectionImpl(DI, &DWARFYAML::EmitDebugAbbrev, "debug_abbrev",
 375                        DebugSections);
 376   EmitDebugSectionImpl(DI, &DWARFYAML::EmitDebugAranges, "debug_aranges",
 377                        DebugSections);
 378   return std::move(DebugSections);
 379 }