[LLVMSymbolize] Move ModuleInfo into a separate class (SymbolizableModule).

[samsonov]

Summary

This is mostly NFC. It is a first step in cleaning up LLVMSymbolize
library. It removes "ModuleInfo" class which bundles together ObjectFile
and its debug info context in favor of:

• abstract SymbolizableModule in public headers;
• SymbolizableObjectFile subclass in implementation.

Additionally, SymbolizableObjectFile is now created via factory, so we
can properly detect object parsing error at this stage instead of keeping
the broken half-parsed object. As a next step, we would be able to
propagate the error all the way back to the library user.

Further improvements might include:

• factoring out the logic of finding appropriate file with debug info for a given object file, and caching all parsed object files into a separate class [A].
• factoring out DILineInfo rendering [B].

This would make what is now a heavyweight "LLVMSymbolizer" a relatively
straightforward class, that calls into [A] to turn filepath into a
SymbolizableModule, delegates actual symbolization to concrete SymbolizableModule
implementation, and lets [C] render the result.

Feel free to express any concerns regarding this plan, or suggest better
alternatives.

[echristo]

Meta: Not a big fan of SymbolizableModule as a name. Especially as we're adding actual Modules with debug info it's going to get confusing. SymbolizableUnit maybe? *shrug*

Couple of inline comments, but otherwise it looks fine.

-eric

lib/DebugInfo/Symbolize/SymbolizableObjectFile.cpp

213–220

Coding style nit.

224–238

Could probably use some more comments here, also if there's a way to unindent a bit of this that'd be awesome.

[samsonov]

Thanks! What do you mean by "Modules with debug info"? :)

include/llvm/DebugInfo/Symbolize/SymbolizableModule.h

+//===-- SymbolizableModule.h ------------------------------------ C++ -----===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file declares the SymbolizableModule interface.
+//
+//===----------------------------------------------------------------------===//
+#ifndef LLVM_DEBUGINFO_SYMBOLIZE_SYMBOLIZABLEMODULE_H
+#define LLVM_DEBUGINFO_SYMBOLIZE_SYMBOLIZABLEMODULE_H
+
+#include "llvm/DebugInfo/DIContext.h"
+#include <memory>
+#include <string>
+
+namespace llvm {
+namespace object {
+class ObjectFile;
+}
+}
+
+namespace llvm {
+namespace symbolize {
+
+using FunctionNameKind = DILineInfoSpecifier::FunctionNameKind;
+
+class SymbolizableModule {
+public:
+  virtual ~SymbolizableModule() {}
+  virtual DILineInfo symbolizeCode(uint64_t ModuleOffset,
+                                   FunctionNameKind FNKind,
+                                   bool UseSymbolTable) const = 0;
+  virtual DIInliningInfo symbolizeInlinedCode(uint64_t ModuleOffset,
+                                              FunctionNameKind FNKind,
+                                              bool UseSymbolTable) const = 0;
+  virtual bool symbolizeData(uint64_t ModuleOffset, std::string &Name,
+                             uint64_t &Start, uint64_t &Size) const = 0;
+
+  // Return true if this is a 32-bit x86 PE COFF module.
+  virtual bool isWin32Module() const = 0;
+
+  // Returns the preferred base of the module, i.e. where the loader would place
+  // it in memory assuming there were no conflicts.
+  virtual uint64_t getModulePreferredBase() const = 0;
+};
+
+}  // namespace symbolize
+}  // namespace llvm
+
+#endif  // LLVM_DEBUGINFO_SYMBOLIZE_SYMBOLIZABLEMODULE_H

include/llvm/DebugInfo/Symbolize/Symbolize.h

 // Header for LLVM symbolization library.
 //
 //===----------------------------------------------------------------------===//
 #ifndef LLVM_DEBUGINFO_SYMBOLIZE_SYMBOLIZE_H
 #define LLVM_DEBUGINFO_SYMBOLIZE_SYMBOLIZE_H
 
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/DebugInfo/DIContext.h"
+#include "llvm/DebugInfo/Symbolize/SymbolizableModule.h"
 #include "llvm/Object/MachOUniversal.h"
 #include "llvm/Object/ObjectFile.h"
-#include "llvm/Support/DataExtractor.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include <map>
 #include <memory>
 #include <string>
 
 namespace llvm {
 namespace symbolize {
 
 using namespace object;
 using FunctionNameKind = DILineInfoSpecifier::FunctionNameKind;
-class ModuleInfo;
 
 class LLVMSymbolizer {
 public:
   struct Options {
     FunctionNameKind PrintFunctions;
     bool UseSymbolTable : 1;
     bool PrintInlining : 1;
     bool Demangle : 1;
public:
 
   // Returns the result of symbolization for module name/offset as
   // a string (possibly containing newlines).
   std::string
   symbolizeCode(const std::string &ModuleName, uint64_t ModuleOffset);
   std::string
   symbolizeData(const std::string &ModuleName, uint64_t ModuleOffset);
   void flush();
-  static std::string DemangleName(const std::string &Name, ModuleInfo *ModInfo);
+  static std::string DemangleName(const std::string &Name,
+                                  const SymbolizableModule *ModInfo);
 
 private:
   typedef std::pair<ObjectFile*, ObjectFile*> ObjectPair;
 
-  ModuleInfo *getOrCreateModuleInfo(const std::string &ModuleName);
-  ObjectFile *lookUpDsymFile(const std::string &Path, const MachOObjectFile *ExeObj,
+  SymbolizableModule *getOrCreateModuleInfo(const std::string &ModuleName);
+  ObjectFile *lookUpDsymFile(const std::string &Path,
+                             const MachOObjectFile *ExeObj,
                              const std::string &ArchName);
 
   /// \brief Returns pair of pointers to object and debug object.
   ObjectPair getOrCreateObjects(const std::string &Path,
                                 const std::string &ArchName);
   /// \brief Returns a parsed object file for a given architecture in a
   /// universal binary (or the binary itself if it is an object file).
   ObjectFile *getObjectFileFromBinary(Binary *Bin, const std::string &ArchName);
 
-  std::string printDILineInfo(DILineInfo LineInfo, ModuleInfo *ModInfo) const;
+  std::string printDILineInfo(DILineInfo LineInfo,
+                              const SymbolizableModule *ModInfo) const;
 
   // Owns all the parsed binaries and object files.
   SmallVector<std::unique_ptr<Binary>, 4> ParsedBinariesAndObjects;
   SmallVector<std::unique_ptr<MemoryBuffer>, 4> MemoryBuffers;
   void addOwningBinary(OwningBinary<Binary> OwningBin) {
     std::unique_ptr<Binary> Bin;
     std::unique_ptr<MemoryBuffer> MemBuf;
     std::tie(Bin, MemBuf) = OwningBin.takeBinary();
     ParsedBinariesAndObjects.push_back(std::move(Bin));
     MemoryBuffers.push_back(std::move(MemBuf));
   }
 
-  std::map<std::string, std::unique_ptr<ModuleInfo>> Modules;
+  std::map<std::string, std::unique_ptr<SymbolizableModule>> Modules;
   std::map<std::pair<MachOUniversalBinary *, std::string>, ObjectFile *>
       ObjectFileForArch;
   std::map<std::pair<std::string, std::string>, ObjectPair>
       ObjectPairForPathArch;
 
   Options Opts;
   static const char kBadString[];
 };
 
-class ModuleInfo {
-public:
-  ModuleInfo(ObjectFile *Obj, std::unique_ptr<DIContext> DICtx);
-
-  DILineInfo symbolizeCode(uint64_t ModuleOffset, FunctionNameKind FNKind,
-                           bool UseSymbolTable) const;
-  DIInliningInfo symbolizeInlinedCode(uint64_t ModuleOffset,
-                                      FunctionNameKind FNKind,
-                                      bool UseSymbolTable) const;
-  bool symbolizeData(uint64_t ModuleOffset, std::string &Name, uint64_t &Start,
-                     uint64_t &Size) const;
-
-  // Return true if this is a 32-bit x86 PE COFF module.
-  bool isWin32Module() const;
-
-  // Returns the preferred base of the module, i.e. where the loader would place
-  // it in memory assuming there were no conflicts.
-  uint64_t getModulePreferredBase() const;
-
-private:
-  bool getNameFromSymbolTable(SymbolRef::Type Type, uint64_t Address,
-                              std::string &Name, uint64_t &Addr,
-                              uint64_t &Size) const;
-  // For big-endian PowerPC64 ELF, OpdAddress is the address of the .opd
-  // (function descriptor) section and OpdExtractor refers to its contents.
-  void addSymbol(const SymbolRef &Symbol, uint64_t SymbolSize,
-                 DataExtractor *OpdExtractor = nullptr,
-                 uint64_t OpdAddress = 0);
-  void addCoffExportSymbols(const COFFObjectFile *CoffObj);
-  ObjectFile *Module;
-  std::unique_ptr<DIContext> DebugInfoContext;
-
-  struct SymbolDesc {
-    uint64_t Addr;
-    // If size is 0, assume that symbol occupies the whole memory range up to
-    // the following symbol.
-    uint64_t Size;
-    friend bool operator<(const SymbolDesc &s1, const SymbolDesc &s2) {
-      return s1.Addr < s2.Addr;
-    }
-  };
-  std::map<SymbolDesc, StringRef> Functions;
-  std::map<SymbolDesc, StringRef> Objects;
-};
-
 } // namespace symbolize
 } // namespace llvm
 
 #endif

lib/DebugInfo/Symbolize/CMakeLists.txt

 add_llvm_library(LLVMSymbolize
   Symbolize.cpp
+  SymbolizableObjectFile.cpp
 
   ADDITIONAL_HEADER_DIRS
   ${LLVM_MAIN_INCLUDE_DIR}/llvm/DebugInfo/Symbolize
   )

lib/DebugInfo/Symbolize/SymbolizableObjectFile.h

+//===-- SymbolizableObjectFile.h -------------------------------- C++ -----===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file declares the SymbolizableObjectFile class.
+//
+//===----------------------------------------------------------------------===//
+#ifndef LLVM_LIB_DEBUGINFO_SYMBOLIZE_SYMBOLIZABLEOBJECTFILE_H
+#define LLVM_LIB_DEBUGINFO_SYMBOLIZE_SYMBOLIZABLEOBJECTFILE_H
+
+#include "llvm/DebugInfo/Symbolize/SymbolizableModule.h"
+#include <map>
+
+namespace llvm {
+class DataExtractor;
+}
+
+namespace llvm {
+namespace symbolize {
+
+class SymbolizableObjectFile : public SymbolizableModule {
+public:
+  static ErrorOr<std::unique_ptr<SymbolizableObjectFile>>
+  create(object::ObjectFile *Obj, std::unique_ptr<DIContext> DICtx);
+
+  DILineInfo symbolizeCode(uint64_t ModuleOffset, FunctionNameKind FNKind,
+                           bool UseSymbolTable) const override;
+  DIInliningInfo symbolizeInlinedCode(uint64_t ModuleOffset,
+                                      FunctionNameKind FNKind,
+                                      bool UseSymbolTable) const override;
+  bool symbolizeData(uint64_t ModuleOffset, std::string &Name, uint64_t &Start,
+                     uint64_t &Size) const override;
+
+  // Return true if this is a 32-bit x86 PE COFF module.
+  bool isWin32Module() const override;
+
+  // Returns the preferred base of the module, i.e. where the loader would place
+  // it in memory assuming there were no conflicts.
+  uint64_t getModulePreferredBase() const override;
+
+private:
+  bool getNameFromSymbolTable(object::SymbolRef::Type Type, uint64_t Address,
+                              std::string &Name, uint64_t &Addr,
+                              uint64_t &Size) const;
+  // For big-endian PowerPC64 ELF, OpdAddress is the address of the .opd
+  // (function descriptor) section and OpdExtractor refers to its contents.
+  std::error_code addSymbol(const object::SymbolRef &Symbol,
+                            uint64_t SymbolSize,
+                            DataExtractor *OpdExtractor = nullptr,
+                            uint64_t OpdAddress = 0);
+  std::error_code addCoffExportSymbols(const object::COFFObjectFile *CoffObj);
+
+  object::ObjectFile *Module;
+  std::unique_ptr<DIContext> DebugInfoContext;
+
+  struct SymbolDesc {
+    uint64_t Addr;
+    // If size is 0, assume that symbol occupies the whole memory range up to
+    // the following symbol.
+    uint64_t Size;
+    friend bool operator<(const SymbolDesc &s1, const SymbolDesc &s2) {
+      return s1.Addr < s2.Addr;
+    }
+  };
+  std::map<SymbolDesc, StringRef> Functions;
+  std::map<SymbolDesc, StringRef> Objects;
+
+  SymbolizableObjectFile(object::ObjectFile *Obj,
+                         std::unique_ptr<DIContext> DICtx);
+};
+
+}  // namespace symbolize
+}  // namespace llvm
+
+#endif  // LLVM_LIB_DEBUGINFO_SYMBOLIZE_SYMBOLIZABLEOBJECTFILE_H

lib/DebugInfo/Symbolize/SymbolizableObjectFile.cpp

+//===-- SymbolizableObjectFile.cpp ----------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Implementation of SymbolizableObjectFile class.
+//
+//===----------------------------------------------------------------------===//
+
+#include "SymbolizableObjectFile.h"
+#include "llvm/Object/SymbolSize.h"
+#include "llvm/Support/DataExtractor.h"
+
+namespace llvm {
+namespace symbolize {
+
+using namespace object;
+
+static DILineInfoSpecifier
+getDILineInfoSpecifier(FunctionNameKind FNKind) {
+  return DILineInfoSpecifier(
+      DILineInfoSpecifier::FileLineInfoKind::AbsoluteFilePath, FNKind);
+}
+
+ErrorOr<std::unique_ptr<SymbolizableObjectFile>>
+SymbolizableObjectFile::create(object::ObjectFile *Obj,
+                               std::unique_ptr<DIContext> DICtx) {
+  std::unique_ptr<SymbolizableObjectFile> res(
+      new SymbolizableObjectFile(Obj, std::move(DICtx)));
+  std::unique_ptr<DataExtractor> OpdExtractor;
+  uint64_t OpdAddress = 0;
+  // Find the .opd (function descriptor) section if any, for big-endian
+  // PowerPC64 ELF.
+  if (Obj->getArch() == Triple::ppc64) {
+    for (section_iterator Section : Obj->sections()) {
+      StringRef Name;
+      StringRef Data;
+      if (auto EC = Section->getName(Name))
+        return EC;
+      if (Name == ".opd") {
+        if (auto EC = Section->getContents(Data))
+          return EC;
+        OpdExtractor.reset(new DataExtractor(Data, Obj->isLittleEndian(),
+                                             Obj->getBytesInAddress()));
+        OpdAddress = Section->getAddress();
+        break;
+      }
+    }
+  }
+  std::vector<std::pair<SymbolRef, uint64_t>> Symbols =
+      computeSymbolSizes(*Obj);
+  for (auto &P : Symbols)
+    res->addSymbol(P.first, P.second, OpdExtractor.get(), OpdAddress);
+
+  // If this is a COFF object and we didn't find any symbols, try the export
+  // table.
+  if (Symbols.empty()) {
+    if (auto *CoffObj = dyn_cast<COFFObjectFile>(Obj))
+      if (auto EC = res->addCoffExportSymbols(CoffObj))
+        return EC;
+  }
+  return std::move(res);
+}
+
+SymbolizableObjectFile::SymbolizableObjectFile(ObjectFile *Obj,
+                                               std::unique_ptr<DIContext> DICtx)
+    : Module(Obj), DebugInfoContext(std::move(DICtx)) {}
+
+namespace {
+struct OffsetNamePair {
+  uint32_t Offset;
+  StringRef Name;
+  bool operator<(const OffsetNamePair &R) const {
+    return Offset < R.Offset;
+  }
+};
+}
+
+std::error_code SymbolizableObjectFile::addCoffExportSymbols(
+    const COFFObjectFile *CoffObj) {
+  // Get all export names and offsets.
+  std::vector<OffsetNamePair> ExportSyms;
+  for (const ExportDirectoryEntryRef &Ref : CoffObj->export_directories()) {
+    StringRef Name;
+    uint32_t Offset;
+    if (auto EC = Ref.getSymbolName(Name))
+      return EC;
+    if (auto EC = Ref.getExportRVA(Offset))
+      return EC;
+    ExportSyms.push_back(OffsetNamePair{Offset, Name});
+  }
+  if (ExportSyms.empty())
+    return std::error_code();
+
+  // Sort by ascending offset.
+  array_pod_sort(ExportSyms.begin(), ExportSyms.end());
+
+  // Approximate the symbol sizes by assuming they run to the next symbol.
+  // FIXME: This assumes all exports are functions.
+  uint64_t ImageBase = CoffObj->getImageBase();
+  for (auto I = ExportSyms.begin(), E = ExportSyms.end(); I != E; ++I) {
+    OffsetNamePair &Export = *I;
+    // FIXME: The last export has a one byte size now.
+    uint32_t NextOffset = I != E ? I->Offset : Export.Offset + 1;
+    uint64_t SymbolStart = ImageBase + Export.Offset;
+    uint64_t SymbolSize = NextOffset - Export.Offset;
+    SymbolDesc SD = {SymbolStart, SymbolSize};
+    Functions.insert(std::make_pair(SD, Export.Name));
+  }
+  return std::error_code();
+}
+
+std::error_code SymbolizableObjectFile::addSymbol(const SymbolRef &Symbol,
+                                                  uint64_t SymbolSize,
+                                                  DataExtractor *OpdExtractor,
+                                                  uint64_t OpdAddress) {
+  SymbolRef::Type SymbolType = Symbol.getType();
+  if (SymbolType != SymbolRef::ST_Function && SymbolType != SymbolRef::ST_Data)
+    return std::error_code();
+  ErrorOr<uint64_t> SymbolAddressOrErr = Symbol.getAddress();
+  if (auto EC = SymbolAddressOrErr.getError())
+    return EC;
+  uint64_t SymbolAddress = *SymbolAddressOrErr;
+  if (OpdExtractor) {
+    // For big-endian PowerPC64 ELF, symbols in the .opd section refer to
+    // function descriptors. The first word of the descriptor is a pointer to
+    // the function's code.
+    // For the purposes of symbolization, pretend the symbol's address is that
+    // of the function's code, not the descriptor.
+    uint64_t OpdOffset = SymbolAddress - OpdAddress;
+    uint32_t OpdOffset32 = OpdOffset;
+    if (OpdOffset == OpdOffset32 && 
+        OpdExtractor->isValidOffsetForAddress(OpdOffset32))
+      SymbolAddress = OpdExtractor->getAddress(&OpdOffset32);
+  }
+  ErrorOr<StringRef> SymbolNameOrErr = Symbol.getName();
+  if (auto EC = SymbolNameOrErr.getError())
+    return EC;
+  StringRef SymbolName = *SymbolNameOrErr;
+  // Mach-O symbol table names have leading underscore, skip it.
+  if (Module->isMachO() && SymbolName.size() > 0 && SymbolName[0] == '_')
+    SymbolName = SymbolName.drop_front();
+  // FIXME: If a function has alias, there are two entries in symbol table
+  // with same address size. Make sure we choose the correct one.
+  auto &M = SymbolType == SymbolRef::ST_Function ? Functions : Objects;
+  SymbolDesc SD = { SymbolAddress, SymbolSize };
+  M.insert(std::make_pair(SD, SymbolName));
+  return std::error_code();
+}
+
+// Return true if this is a 32-bit x86 PE COFF module.
+bool SymbolizableObjectFile::isWin32Module() const {
+  auto *CoffObject = dyn_cast<COFFObjectFile>(Module);
+  return CoffObject && CoffObject->getMachine() == COFF::IMAGE_FILE_MACHINE_I386;
+}
+
+uint64_t SymbolizableObjectFile::getModulePreferredBase() const {
+  if (auto *CoffObject = dyn_cast<COFFObjectFile>(Module))
+    return CoffObject->getImageBase();
+  return 0;
+}
+
+bool SymbolizableObjectFile::getNameFromSymbolTable(SymbolRef::Type Type,
+                                                    uint64_t Address,
+                                                    std::string &Name,
+                                                    uint64_t &Addr,
+                                                    uint64_t &Size) const {
+  const auto &SymbolMap = Type == SymbolRef::ST_Function ? Functions : Objects;
+  if (SymbolMap.empty())
+    return false;
+  SymbolDesc SD = { Address, Address };
+  auto SymbolIterator = SymbolMap.upper_bound(SD);
+  if (SymbolIterator == SymbolMap.begin())
+    return false;
+  --SymbolIterator;
+  if (SymbolIterator->first.Size != 0 &&
+      SymbolIterator->first.Addr + SymbolIterator->first.Size <= Address)
+    return false;
+  Name = SymbolIterator->second.str();
+  Addr = SymbolIterator->first.Addr;
+  Size = SymbolIterator->first.Size;
+  return true;
+}
+
+DILineInfo SymbolizableObjectFile::symbolizeCode(uint64_t ModuleOffset,
+                                                 FunctionNameKind FNKind,
+                                                 bool UseSymbolTable) const {
+  DILineInfo LineInfo;
+  if (DebugInfoContext) {
+    LineInfo = DebugInfoContext->getLineInfoForAddress(
+        ModuleOffset, getDILineInfoSpecifier(FNKind));
+  }
+  // Override function name from symbol table if necessary.
+  if (FNKind == FunctionNameKind::LinkageName && UseSymbolTable) {
+    std::string FunctionName;
+    uint64_t Start, Size;
+    if (getNameFromSymbolTable(SymbolRef::ST_Function, ModuleOffset,
+                               FunctionName, Start, Size)) {
+      LineInfo.FunctionName = FunctionName;
+    }
+  }
+  return LineInfo;
+}
+
+DIInliningInfo SymbolizableObjectFile::symbolizeInlinedCode(
+    uint64_t ModuleOffset, FunctionNameKind FNKind, bool UseSymbolTable) const {
+  DIInliningInfo InlinedContext;
+
+  if (DebugInfoContext) {
+    InlinedContext = DebugInfoContext->getInliningInfoForAddress(
+        ModuleOffset, getDILineInfoSpecifier(FNKind));
+  }
+  // Make sure there is at least one frame in context.
+  if (InlinedContext.getNumberOfFrames() == 0) {
+    InlinedContext.addFrame(DILineInfo());
+  }
+  // Override the function name in lower frame with name from symbol table.
+  if (FNKind == FunctionNameKind::LinkageName && UseSymbolTable) {
+    DIInliningInfo PatchedInlinedContext;
+    for (uint32_t i = 0, n = InlinedContext.getNumberOfFrames(); i < n; i++) {
+      DILineInfo LineInfo = InlinedContext.getFrame(i);
+      if (i == n - 1) {
+        std::string FunctionName;
+        uint64_t Start, Size;
+        if (getNameFromSymbolTable(SymbolRef::ST_Function, ModuleOffset,
+                                   FunctionName, Start, Size)) {
+          LineInfo.FunctionName = FunctionName;
+        }
+      }
+      PatchedInlinedContext.addFrame(LineInfo);
+    }
+    InlinedContext = PatchedInlinedContext;
+  }
+  return InlinedContext;
+}
+
+bool SymbolizableObjectFile::symbolizeData(uint64_t ModuleOffset,
+                                           std::string &Name, uint64_t &Start,
+                                           uint64_t &Size) const {
+  return getNameFromSymbolTable(SymbolRef::ST_Data, ModuleOffset, Name, Start,
+                                Size);
+}
+
+}  // namespace symbolize
+}  // namespace llvm
+

lib/DebugInfo/Symbolize/Symbolize.cpp

 //===-- LLVMSymbolize.cpp -------------------------------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // Implementation for LLVM symbolization library.
 //
 //===----------------------------------------------------------------------===//
 
 #include "llvm/DebugInfo/Symbolize/Symbolize.h"
 
+#include "SymbolizableObjectFile.h"
+
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/Config/config.h"
 #include "llvm/DebugInfo/DWARF/DWARFContext.h"
 #include "llvm/DebugInfo/PDB/PDB.h"
 #include "llvm/DebugInfo/PDB/PDBContext.h"
 #include "llvm/Object/ELFObjectFile.h"
 #include "llvm/Object/MachO.h"
-#include "llvm/Object/SymbolSize.h"
 #include "llvm/Support/COFF.h"
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/Compression.h"
 #include "llvm/Support/DataExtractor.h"
 #include "llvm/Support/Errc.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/Path.h"

 // FIXME: Move this to llvm-symbolizer tool.
 static bool error(std::error_code ec) {
   if (!ec)
     return false;
   errs() << "LLVMSymbolizer: error reading file: " << ec.message() << ".\n";
   return true;
 }
 
-static DILineInfoSpecifier
-getDILineInfoSpecifier(FunctionNameKind FNKind) {
-  return DILineInfoSpecifier(
-      DILineInfoSpecifier::FileLineInfoKind::AbsoluteFilePath, FNKind);
-}
-
-ModuleInfo::ModuleInfo(ObjectFile *Obj, std::unique_ptr<DIContext> DICtx)
-    : Module(Obj), DebugInfoContext(std::move(DICtx)) {
-  std::unique_ptr<DataExtractor> OpdExtractor;
-  uint64_t OpdAddress = 0;
-  // Find the .opd (function descriptor) section if any, for big-endian
-  // PowerPC64 ELF.
-  if (Module->getArch() == Triple::ppc64) {
-    for (section_iterator Section : Module->sections()) {
-      StringRef Name;
-      if (!error(Section->getName(Name)) && Name == ".opd") {
-        StringRef Data;
-        if (!error(Section->getContents(Data))) {
-          OpdExtractor.reset(new DataExtractor(Data, Module->isLittleEndian(),
-                                               Module->getBytesInAddress()));
-          OpdAddress = Section->getAddress();
-        }
-        break;
-      }
-    }
-  }
-  std::vector<std::pair<SymbolRef, uint64_t>> Symbols =
-      computeSymbolSizes(*Module);
-  for (auto &P : Symbols)
-    addSymbol(P.first, P.second, OpdExtractor.get(), OpdAddress);
-
-  // If this is a COFF object and we didn't find any symbols, try the export
-  // table.
-  if (Symbols.empty()) {
-    if (auto *CoffObj = dyn_cast<COFFObjectFile>(Obj))
-      addCoffExportSymbols(CoffObj);
-  }
-}
-
-namespace {
-struct OffsetNamePair {
-  uint32_t Offset;
-  StringRef Name;
-  bool operator<(const OffsetNamePair &R) const {
-    return Offset < R.Offset;
-  }
-};
-}
-
-void ModuleInfo::addCoffExportSymbols(const COFFObjectFile *CoffObj) {
-  // Get all export names and offsets.
-  std::vector<OffsetNamePair> ExportSyms;
-  for (const ExportDirectoryEntryRef &Ref : CoffObj->export_directories()) {
-    StringRef Name;
-    uint32_t Offset;
-    if (error(Ref.getSymbolName(Name)) || error(Ref.getExportRVA(Offset)))
-      return;
-    ExportSyms.push_back(OffsetNamePair{Offset, Name});
-  }
-  if (ExportSyms.empty())
-    return;
-
-  // Sort by ascending offset.
-  array_pod_sort(ExportSyms.begin(), ExportSyms.end());
-
-  // Approximate the symbol sizes by assuming they run to the next symbol.
-  // FIXME: This assumes all exports are functions.
-  uint64_t ImageBase = CoffObj->getImageBase();
-  for (auto I = ExportSyms.begin(), E = ExportSyms.end(); I != E; ++I) {
-    OffsetNamePair &Export = *I;
-    // FIXME: The last export has a one byte size now.
-    uint32_t NextOffset = I != E ? I->Offset : Export.Offset + 1;
-    uint64_t SymbolStart = ImageBase + Export.Offset;
-    uint64_t SymbolSize = NextOffset - Export.Offset;
-    SymbolDesc SD = {SymbolStart, SymbolSize};
-    Functions.insert(std::make_pair(SD, Export.Name));
-  }
-}
-
-void ModuleInfo::addSymbol(const SymbolRef &Symbol, uint64_t SymbolSize,
-                           DataExtractor *OpdExtractor, uint64_t OpdAddress) {
-  SymbolRef::Type SymbolType = Symbol.getType();
-  if (SymbolType != SymbolRef::ST_Function && SymbolType != SymbolRef::ST_Data)
-    return;
-  ErrorOr<uint64_t> SymbolAddressOrErr = Symbol.getAddress();
-  if (error(SymbolAddressOrErr.getError()))
-    return;
-  uint64_t SymbolAddress = *SymbolAddressOrErr;
-  if (OpdExtractor) {
-    // For big-endian PowerPC64 ELF, symbols in the .opd section refer to
-    // function descriptors. The first word of the descriptor is a pointer to
-    // the function's code.
-    // For the purposes of symbolization, pretend the symbol's address is that
-    // of the function's code, not the descriptor.
-    uint64_t OpdOffset = SymbolAddress - OpdAddress;
-    uint32_t OpdOffset32 = OpdOffset;
-    if (OpdOffset == OpdOffset32 && 
-        OpdExtractor->isValidOffsetForAddress(OpdOffset32))
-      SymbolAddress = OpdExtractor->getAddress(&OpdOffset32);
-  }
-  ErrorOr<StringRef> SymbolNameOrErr = Symbol.getName();
-  if (error(SymbolNameOrErr.getError()))
-    return;
-  StringRef SymbolName = *SymbolNameOrErr;
-  // Mach-O symbol table names have leading underscore, skip it.
-  if (Module->isMachO() && SymbolName.size() > 0 && SymbolName[0] == '_')
-    SymbolName = SymbolName.drop_front();
-  // FIXME: If a function has alias, there are two entries in symbol table
-  // with same address size. Make sure we choose the correct one.
-  auto &M = SymbolType == SymbolRef::ST_Function ? Functions : Objects;
-  SymbolDesc SD = { SymbolAddress, SymbolSize };
-  M.insert(std::make_pair(SD, SymbolName));
-}
-
-// Return true if this is a 32-bit x86 PE COFF module.
-bool ModuleInfo::isWin32Module() const {
-  auto *CoffObject = dyn_cast<COFFObjectFile>(Module);
-  return CoffObject && CoffObject->getMachine() == COFF::IMAGE_FILE_MACHINE_I386;
-}
-
-uint64_t ModuleInfo::getModulePreferredBase() const {
-  if (auto *CoffObject = dyn_cast<COFFObjectFile>(Module))
-    return CoffObject->getImageBase();
-  return 0;
-}
-
-bool ModuleInfo::getNameFromSymbolTable(SymbolRef::Type Type, uint64_t Address,
-                                        std::string &Name, uint64_t &Addr,
-                                        uint64_t &Size) const {
-  const auto &SymbolMap = Type == SymbolRef::ST_Function ? Functions : Objects;
-  if (SymbolMap.empty())
-    return false;
-  SymbolDesc SD = { Address, Address };
-  auto SymbolIterator = SymbolMap.upper_bound(SD);
-  if (SymbolIterator == SymbolMap.begin())
-    return false;
-  --SymbolIterator;
-  if (SymbolIterator->first.Size != 0 &&
-      SymbolIterator->first.Addr + SymbolIterator->first.Size <= Address)
-    return false;
-  Name = SymbolIterator->second.str();
-  Addr = SymbolIterator->first.Addr;
-  Size = SymbolIterator->first.Size;
-  return true;
-}
-
-DILineInfo ModuleInfo::symbolizeCode(uint64_t ModuleOffset,
-                                     FunctionNameKind FNKind,
-                                     bool UseSymbolTable) const {
-  DILineInfo LineInfo;
-  if (DebugInfoContext) {
-    LineInfo = DebugInfoContext->getLineInfoForAddress(
-        ModuleOffset, getDILineInfoSpecifier(FNKind));
-  }
-  // Override function name from symbol table if necessary.
-  if (FNKind == FunctionNameKind::LinkageName && UseSymbolTable) {
-    std::string FunctionName;
-    uint64_t Start, Size;
-    if (getNameFromSymbolTable(SymbolRef::ST_Function, ModuleOffset,
-                               FunctionName, Start, Size)) {
-      LineInfo.FunctionName = FunctionName;
-    }
-  }
-  return LineInfo;
-}
-
-DIInliningInfo ModuleInfo::symbolizeInlinedCode(uint64_t ModuleOffset,
-                                                FunctionNameKind FNKind,
-                                                bool UseSymbolTable) const {
-  DIInliningInfo InlinedContext;
-
-  if (DebugInfoContext) {
-    InlinedContext = DebugInfoContext->getInliningInfoForAddress(
-        ModuleOffset, getDILineInfoSpecifier(FNKind));
-  }
-  // Make sure there is at least one frame in context.
-  if (InlinedContext.getNumberOfFrames() == 0) {
-    InlinedContext.addFrame(DILineInfo());
-  }
-  // Override the function name in lower frame with name from symbol table.
-  if (FNKind == FunctionNameKind::LinkageName && UseSymbolTable) {
-    DIInliningInfo PatchedInlinedContext;
-    for (uint32_t i = 0, n = InlinedContext.getNumberOfFrames(); i < n; i++) {
-      DILineInfo LineInfo = InlinedContext.getFrame(i);
-      if (i == n - 1) {
-        std::string FunctionName;
-        uint64_t Start, Size;
-        if (getNameFromSymbolTable(SymbolRef::ST_Function, ModuleOffset,
-                                   FunctionName, Start, Size)) {
-          LineInfo.FunctionName = FunctionName;
-        }
-      }
-      PatchedInlinedContext.addFrame(LineInfo);
-    }
-    InlinedContext = PatchedInlinedContext;
-  }
-  return InlinedContext;
-}
-
-bool ModuleInfo::symbolizeData(uint64_t ModuleOffset, std::string &Name,
-                               uint64_t &Start, uint64_t &Size) const {
-  return getNameFromSymbolTable(SymbolRef::ST_Data, ModuleOffset, Name, Start,
-                                Size);
-}
 
 const char LLVMSymbolizer::kBadString[] = "??";
 
 std::string LLVMSymbolizer::symbolizeCode(const std::string &ModuleName,
                                           uint64_t ModuleOffset) {
-  ModuleInfo *Info = getOrCreateModuleInfo(ModuleName);
+  SymbolizableModule *Info = getOrCreateModuleInfo(ModuleName);
   if (!Info)
     return printDILineInfo(DILineInfo(), Info);
 
   // If the user is giving us relative addresses, add the preferred base of the
   // object to the offset before we do the query. It's what DIContext expects.
   if (Opts.RelativeAddresses)
     ModuleOffset += Info->getModulePreferredBase();
 

 }
 
 std::string LLVMSymbolizer::symbolizeData(const std::string &ModuleName,
                                           uint64_t ModuleOffset) {
   std::string Name = kBadString;
   uint64_t Start = 0;
   uint64_t Size = 0;
   if (Opts.UseSymbolTable) {
-    if (ModuleInfo *Info = getOrCreateModuleInfo(ModuleName)) {
-      // If the user is giving us relative addresses, add the preferred base of the
-      // object to the offset before we do the query. It's what DIContext expects.
+    if (SymbolizableModule *Info = getOrCreateModuleInfo(ModuleName)) {
+      // If the user is giving us relative addresses, add the preferred base of
+      // the object to the offset before we do the query. It's what DIContext
+      // expects.
       if (Opts.RelativeAddresses)
         ModuleOffset += Info->getModulePreferredBase();
       if (Info->symbolizeData(ModuleOffset, Name, Start, Size) && Opts.Demangle)
         Name = DemangleName(Name, Info);
     }
   }
   std::stringstream ss;
   ss << Name << "\n" << Start << " " << Size << "\n";
if (MachOUniversalBinary *UB = dyn_cast<MachOUniversalBinary>(Bin)) {
     }
     ObjectFileForArch[std::make_pair(UB, ArchName)] = Res;
   } else if (Bin->isObject()) {
     Res = cast<ObjectFile>(Bin);
   }
   return Res;
 }
 
-ModuleInfo *
+SymbolizableModule *
 LLVMSymbolizer::getOrCreateModuleInfo(const std::string &ModuleName) {
   const auto &I = Modules.find(ModuleName);
   if (I != Modules.end())
     return I->second.get();
   std::string BinaryName = ModuleName;
   std::string ArchName = Opts.DefaultArch;
   size_t ColonPos = ModuleName.find_last_of(':');
   // Verify that substring after colon form a valid arch name.
   if (ColonPos != std::string::npos) {
     std::string ArchStr = ModuleName.substr(ColonPos + 1);
     if (Triple(ArchStr).getArch() != Triple::UnknownArch) {
       BinaryName = ModuleName.substr(0, ColonPos);
       ArchName = ArchStr;
     }
   }
   ObjectPair Objects = getOrCreateObjects(BinaryName, ArchName);
 
   if (!Objects.first) {
     // Failed to find valid object file.
-    Modules.insert(
-        std::make_pair(ModuleName, std::unique_ptr<ModuleInfo>(nullptr)));
+    Modules.insert(std::make_pair(ModuleName, nullptr));
     return nullptr;
   }
   std::unique_ptr<DIContext> Context;
   if (auto CoffObject = dyn_cast<COFFObjectFile>(Objects.first)) {
     // If this is a COFF object, assume it contains PDB debug information.  If
     // we don't find any we will fall back to the DWARF case.
     std::unique_ptr<IPDBSession> Session;
     PDB_ErrorCode Error = loadDataForEXE(PDB_ReaderType::DIA,
                                          Objects.first->getFileName(), Session);
     if (Error == PDB_ErrorCode::Success) {
       Context.reset(new PDBContext(*CoffObject, std::move(Session)));
     }
   }
   if (!Context)
     Context.reset(new DWARFContextInMemory(*Objects.second));
   assert(Context);
-  auto Info = llvm::make_unique<ModuleInfo>(Objects.first, std::move(Context));
-  ModuleInfo *Res = Info.get();
-  Modules.insert(std::make_pair(ModuleName, std::move(Info)));
+  auto ErrOrInfo =
+      SymbolizableObjectFile::create(Objects.first, std::move(Context));
+  if (error(ErrOrInfo.getError())) {
+    Modules.insert(std::make_pair(ModuleName, nullptr));
+    return nullptr;
+  }
+  SymbolizableModule *Res = ErrOrInfo.get().get();
+  Modules.insert(std::make_pair(ModuleName, std::move(ErrOrInfo.get())));
   return Res;
 }
 
-std::string LLVMSymbolizer::printDILineInfo(DILineInfo LineInfo,
-                                            ModuleInfo *ModInfo) const {
+std::string
+LLVMSymbolizer::printDILineInfo(DILineInfo LineInfo,
+                                const SymbolizableModule *ModInfo) const {
   // By default, DILineInfo contains "<invalid>" for function/filename it
   // cannot fetch. We replace it to "??" to make our output closer to addr2line.
   static const std::string kDILineInfoBadString = "<invalid>";
   std::stringstream Result;
   if (Opts.PrintFunctions != FunctionNameKind::None) {
     std::string FunctionName = LineInfo.FunctionName;
     if (FunctionName == kDILineInfoBadString)
       FunctionName = kBadString;

 
 #if !defined(_MSC_VER)
 // Assume that __cxa_demangle is provided by libcxxabi (except for Windows).
 extern "C" char *__cxa_demangle(const char *mangled_name, char *output_buffer,
                                 size_t *length, int *status);
 #endif
 
 std::string LLVMSymbolizer::DemangleName(const std::string &Name,
-                                         ModuleInfo *ModInfo) {
+                                         const SymbolizableModule *ModInfo) {
 #if !defined(_MSC_VER)
   // We can spoil names of symbols with C linkage, so use an heuristic
   // approach to check if the name should be demangled.
   if (Name.substr(0, 2) == "_Z") {
     int status = 0;
     char *DemangledName = __cxa_demangle(Name.c_str(), nullptr, nullptr, &status);
     if (status != 0)
       return Name;