Make ObjectFile and BitcodeReader always own the MemoryBuffer.

This allows us to just use a std::unique_ptr to store the pointer to the buffer.
The flip side is that they have to support releasing the buffer back to the
caller.

Overall this looks like a more efficient and less brittle api.

llvm-svn: 211542
diff --git a/llvm/lib/Object/Archive.cpp b/llvm/lib/Object/Archive.cpp
index 05e8913..cd89249 100644
--- a/llvm/lib/Object/Archive.cpp
+++ b/llvm/lib/Object/Archive.cpp
@@ -181,7 +181,12 @@
   ErrorOr<std::unique_ptr<MemoryBuffer>> BuffOrErr = getMemoryBuffer();
   if (std::error_code EC = BuffOrErr.getError())
     return EC;
-  return createBinary(BuffOrErr.get().release(), Context);
+
+  std::unique_ptr<MemoryBuffer> Buff(BuffOrErr.get().release());
+  ErrorOr<std::unique_ptr<Binary>> Ret = createBinary(Buff.get(), Context);
+  if (!Ret.getError())
+    Buff.release();
+  return Ret;
 }
 
 ErrorOr<Archive*> Archive::create(MemoryBuffer *Source) {
diff --git a/llvm/lib/Object/Binary.cpp b/llvm/lib/Object/Binary.cpp
index c55ed0c..785b3d2 100644
--- a/llvm/lib/Object/Binary.cpp
+++ b/llvm/lib/Object/Binary.cpp
@@ -25,13 +25,10 @@
 using namespace llvm;
 using namespace object;
 
-Binary::~Binary() {
-  if (BufferOwned)
-    delete Data;
-}
+Binary::~Binary() {}
 
-Binary::Binary(unsigned int Type, MemoryBuffer *Source, bool BufferOwned)
-  : TypeID(Type), BufferOwned(BufferOwned), Data(Source) {}
+Binary::Binary(unsigned int Type, MemoryBuffer *Source)
+    : TypeID(Type), Data(Source) {}
 
 StringRef Binary::getData() const {
   return Data->getBuffer();
@@ -41,14 +38,13 @@
   return Data->getBufferIdentifier();
 }
 
-ErrorOr<Binary *> object::createBinary(MemoryBuffer *Source,
+ErrorOr<Binary *> object::createBinary(MemoryBuffer *Buffer,
                                        LLVMContext *Context) {
-  std::unique_ptr<MemoryBuffer> scopedSource(Source);
-  sys::fs::file_magic Type = sys::fs::identify_magic(Source->getBuffer());
+  sys::fs::file_magic Type = sys::fs::identify_magic(Buffer->getBuffer());
 
   switch (Type) {
     case sys::fs::file_magic::archive:
-      return Archive::create(scopedSource.release());
+      return Archive::create(Buffer);
     case sys::fs::file_magic::elf_relocatable:
     case sys::fs::file_magic::elf_executable:
     case sys::fs::file_magic::elf_shared_object:
@@ -67,10 +63,9 @@
     case sys::fs::file_magic::coff_import_library:
     case sys::fs::file_magic::pecoff_executable:
     case sys::fs::file_magic::bitcode:
-      return ObjectFile::createSymbolicFile(scopedSource.release(), true, Type,
-                                            Context);
+      return ObjectFile::createSymbolicFile(Buffer, Type, Context);
     case sys::fs::file_magic::macho_universal_binary:
-      return MachOUniversalBinary::create(scopedSource.release());
+      return MachOUniversalBinary::create(Buffer);
     case sys::fs::file_magic::unknown:
     case sys::fs::file_magic::windows_resource:
       // Unrecognized object file format.
diff --git a/llvm/lib/Object/COFFObjectFile.cpp b/llvm/lib/Object/COFFObjectFile.cpp
index 186d64b..1b14974 100644
--- a/llvm/lib/Object/COFFObjectFile.cpp
+++ b/llvm/lib/Object/COFFObjectFile.cpp
@@ -31,9 +31,9 @@
 using support::little16_t;
 
 // Returns false if size is greater than the buffer size. And sets ec.
-static bool checkSize(const MemoryBuffer *M, std::error_code &EC,
+static bool checkSize(const MemoryBuffer &M, std::error_code &EC,
                       uint64_t Size) {
-  if (M->getBufferSize() < Size) {
+  if (M.getBufferSize() < Size) {
     EC = object_error::unexpected_eof;
     return false;
   }
@@ -43,13 +43,12 @@
 // Sets Obj unless any bytes in [addr, addr + size) fall outsize of m.
 // Returns unexpected_eof if error.
 template <typename T>
-static std::error_code getObject(const T *&Obj, const MemoryBuffer *M,
+static std::error_code getObject(const T *&Obj, const MemoryBuffer &M,
                                  const uint8_t *Ptr,
                                  const size_t Size = sizeof(T)) {
   uintptr_t Addr = uintptr_t(Ptr);
-  if (Addr + Size < Addr ||
-      Addr + Size < Size ||
-      Addr + Size > uintptr_t(M->getBufferEnd())) {
+  if (Addr + Size < Addr || Addr + Size < Size ||
+      Addr + Size > uintptr_t(M.getBufferEnd())) {
     return object_error::unexpected_eof;
   }
   Obj = reinterpret_cast<const T *>(Addr);
@@ -398,7 +397,7 @@
 // Initialize the pointer to the symbol table.
 std::error_code COFFObjectFile::initSymbolTablePtr() {
   if (std::error_code EC = getObject(
-          SymbolTable, Data, base() + COFFHeader->PointerToSymbolTable,
+          SymbolTable, *Data, base() + COFFHeader->PointerToSymbolTable,
           COFFHeader->NumberOfSymbols * sizeof(coff_symbol)))
     return EC;
 
@@ -409,11 +408,12 @@
       base() + COFFHeader->PointerToSymbolTable +
       COFFHeader->NumberOfSymbols * sizeof(coff_symbol);
   const ulittle32_t *StringTableSizePtr;
-  if (std::error_code EC = getObject(StringTableSizePtr, Data, StringTableAddr))
+  if (std::error_code EC =
+          getObject(StringTableSizePtr, *Data, StringTableAddr))
     return EC;
   StringTableSize = *StringTableSizePtr;
   if (std::error_code EC =
-          getObject(StringTable, Data, StringTableAddr, StringTableSize))
+          getObject(StringTable, *Data, StringTableAddr, StringTableSize))
     return EC;
 
   // Treat table sizes < 4 as empty because contrary to the PECOFF spec, some
@@ -511,15 +511,15 @@
   return object_error::success;
 }
 
-COFFObjectFile::COFFObjectFile(MemoryBuffer *Object, std::error_code &EC,
-                               bool BufferOwned)
-    : ObjectFile(Binary::ID_COFF, Object, BufferOwned), COFFHeader(nullptr),
+COFFObjectFile::COFFObjectFile(MemoryBuffer *Object, std::error_code &EC)
+    : ObjectFile(Binary::ID_COFF, Object), COFFHeader(nullptr),
       PE32Header(nullptr), PE32PlusHeader(nullptr), DataDirectory(nullptr),
       SectionTable(nullptr), SymbolTable(nullptr), StringTable(nullptr),
       StringTableSize(0), ImportDirectory(nullptr), NumberOfImportDirectory(0),
       ExportDirectory(nullptr) {
   // Check that we at least have enough room for a header.
-  if (!checkSize(Data, EC, sizeof(coff_file_header))) return;
+  if (!checkSize(*Data, EC, sizeof(coff_file_header)))
+    return;
 
   // The current location in the file where we are looking at.
   uint64_t CurPtr = 0;
@@ -532,7 +532,8 @@
   if (base()[0] == 0x4d && base()[1] == 0x5a) {
     // PE/COFF, seek through MS-DOS compatibility stub and 4-byte
     // PE signature to find 'normal' COFF header.
-    if (!checkSize(Data, EC, 0x3c + 8)) return;
+    if (!checkSize(*Data, EC, 0x3c + 8))
+      return;
     CurPtr = *reinterpret_cast<const ulittle16_t *>(base() + 0x3c);
     // Check the PE magic bytes. ("PE\0\0")
     if (std::memcmp(base() + CurPtr, "PE\0\0", 4) != 0) {
@@ -543,13 +544,13 @@
     HasPEHeader = true;
   }
 
-  if ((EC = getObject(COFFHeader, Data, base() + CurPtr)))
+  if ((EC = getObject(COFFHeader, *Data, base() + CurPtr)))
     return;
   CurPtr += sizeof(coff_file_header);
 
   if (HasPEHeader) {
     const pe32_header *Header;
-    if ((EC = getObject(Header, Data, base() + CurPtr)))
+    if ((EC = getObject(Header, *Data, base() + CurPtr)))
       return;
 
     const uint8_t *DataDirAddr;
@@ -567,7 +568,7 @@
       EC = object_error::parse_failed;
       return;
     }
-    if ((EC = getObject(DataDirectory, Data, DataDirAddr, DataDirSize)))
+    if ((EC = getObject(DataDirectory, *Data, DataDirAddr, DataDirSize)))
       return;
     CurPtr += COFFHeader->SizeOfOptionalHeader;
   }
@@ -575,7 +576,7 @@
   if (COFFHeader->isImportLibrary())
     return;
 
-  if ((EC = getObject(SectionTable, Data, base() + CurPtr,
+  if ((EC = getObject(SectionTable, *Data, base() + CurPtr,
                       COFFHeader->NumberOfSections * sizeof(coff_section))))
     return;
 
@@ -1110,11 +1111,9 @@
   return object_error::success;
 }
 
-ErrorOr<ObjectFile *> ObjectFile::createCOFFObjectFile(MemoryBuffer *Object,
-                                                       bool BufferOwned) {
+ErrorOr<ObjectFile *> ObjectFile::createCOFFObjectFile(MemoryBuffer *Object) {
   std::error_code EC;
-  std::unique_ptr<COFFObjectFile> Ret(
-      new COFFObjectFile(Object, EC, BufferOwned));
+  std::unique_ptr<COFFObjectFile> Ret(new COFFObjectFile(Object, EC));
   if (EC)
     return EC;
   return Ret.release();
diff --git a/llvm/lib/Object/ELFObjectFile.cpp b/llvm/lib/Object/ELFObjectFile.cpp
index 0a3e2cb..295cb11 100644
--- a/llvm/lib/Object/ELFObjectFile.cpp
+++ b/llvm/lib/Object/ELFObjectFile.cpp
@@ -17,8 +17,7 @@
 namespace llvm {
 using namespace object;
 
-static ErrorOr<ObjectFile *> createELFObjectFileAux(MemoryBuffer *Obj,
-                                                    bool BufferOwned) {
+ErrorOr<ObjectFile *> ObjectFile::createELFObjectFile(MemoryBuffer *Obj) {
   std::pair<unsigned char, unsigned char> Ident = getElfArchType(Obj);
   std::size_t MaxAlignment =
     1ULL << countTrailingZeros(uintptr_t(Obj->getBufferStart()));
@@ -28,49 +27,41 @@
   if (Ident.first == ELF::ELFCLASS32 && Ident.second == ELF::ELFDATA2LSB)
 #if !LLVM_IS_UNALIGNED_ACCESS_FAST
     if (MaxAlignment >= 4)
-      R.reset(new ELFObjectFile<ELFType<support::little, 4, false> >(
-          Obj, EC, BufferOwned));
+      R.reset(new ELFObjectFile<ELFType<support::little, 4, false>>(Obj, EC));
     else
 #endif
     if (MaxAlignment >= 2)
-      R.reset(new ELFObjectFile<ELFType<support::little, 2, false> >(
-          Obj, EC, BufferOwned));
+      R.reset(new ELFObjectFile<ELFType<support::little, 2, false>>(Obj, EC));
     else
       return object_error::parse_failed;
   else if (Ident.first == ELF::ELFCLASS32 && Ident.second == ELF::ELFDATA2MSB)
 #if !LLVM_IS_UNALIGNED_ACCESS_FAST
     if (MaxAlignment >= 4)
-      R.reset(new ELFObjectFile<ELFType<support::big, 4, false> >(Obj, EC,
-                                                                  BufferOwned));
+      R.reset(new ELFObjectFile<ELFType<support::big, 4, false>>(Obj, EC));
     else
 #endif
     if (MaxAlignment >= 2)
-      R.reset(new ELFObjectFile<ELFType<support::big, 2, false> >(Obj, EC,
-                                                                  BufferOwned));
+      R.reset(new ELFObjectFile<ELFType<support::big, 2, false>>(Obj, EC));
     else
       return object_error::parse_failed;
   else if (Ident.first == ELF::ELFCLASS64 && Ident.second == ELF::ELFDATA2MSB)
 #if !LLVM_IS_UNALIGNED_ACCESS_FAST
     if (MaxAlignment >= 8)
-      R.reset(new ELFObjectFile<ELFType<support::big, 8, true> >(Obj, EC,
-                                                                 BufferOwned));
+      R.reset(new ELFObjectFile<ELFType<support::big, 8, true>>(Obj, EC));
     else
 #endif
     if (MaxAlignment >= 2)
-      R.reset(new ELFObjectFile<ELFType<support::big, 2, true> >(Obj, EC,
-                                                                 BufferOwned));
+      R.reset(new ELFObjectFile<ELFType<support::big, 2, true>>(Obj, EC));
     else
       return object_error::parse_failed;
   else if (Ident.first == ELF::ELFCLASS64 && Ident.second == ELF::ELFDATA2LSB) {
 #if !LLVM_IS_UNALIGNED_ACCESS_FAST
     if (MaxAlignment >= 8)
-      R.reset(new ELFObjectFile<ELFType<support::little, 8, true> >(
-          Obj, EC, BufferOwned));
+      R.reset(new ELFObjectFile<ELFType<support::little, 8, true>>(Obj, EC));
     else
 #endif
     if (MaxAlignment >= 2)
-      R.reset(new ELFObjectFile<ELFType<support::little, 2, true> >(
-          Obj, EC, BufferOwned));
+      R.reset(new ELFObjectFile<ELFType<support::little, 2, true>>(Obj, EC));
     else
       return object_error::parse_failed;
   }
@@ -82,12 +73,4 @@
   return R.release();
 }
 
-ErrorOr<ObjectFile *> ObjectFile::createELFObjectFile(MemoryBuffer *Obj,
-                                                      bool BufferOwned) {
-  ErrorOr<ObjectFile *> Ret = createELFObjectFileAux(Obj, BufferOwned);
-  if (BufferOwned && Ret.getError())
-    delete Obj;
-  return Ret;
-}
-
 } // end namespace llvm
diff --git a/llvm/lib/Object/IRObjectFile.cpp b/llvm/lib/Object/IRObjectFile.cpp
index 004d8de..ef544aa 100644
--- a/llvm/lib/Object/IRObjectFile.cpp
+++ b/llvm/lib/Object/IRObjectFile.cpp
@@ -13,6 +13,7 @@
 
 #include "llvm/Bitcode/ReaderWriter.h"
 #include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/GVMaterializer.h"
 #include "llvm/IR/Mangler.h"
 #include "llvm/IR/Module.h"
 #include "llvm/Object/IRObjectFile.h"
@@ -21,10 +22,9 @@
 using namespace object;
 
 IRObjectFile::IRObjectFile(MemoryBuffer *Object, std::error_code &EC,
-                           LLVMContext &Context, bool BufferOwned)
-    : SymbolicFile(Binary::ID_IR, Object, BufferOwned) {
-  ErrorOr<Module *> MOrErr =
-      getLazyBitcodeModule(Object, Context, /*BufferOwned*/ false);
+                           LLVMContext &Context)
+    : SymbolicFile(Binary::ID_IR, Object) {
+  ErrorOr<Module *> MOrErr = getLazyBitcodeModule(Object, Context);
   if ((EC = MOrErr.getError()))
     return;
 
@@ -38,6 +38,8 @@
   Mang.reset(new Mangler(DL));
 }
 
+IRObjectFile::~IRObjectFile() { M->getMaterializer()->releaseBuffer(); }
+
 static const GlobalValue &getGV(DataRefImpl &Symb) {
   return *reinterpret_cast<GlobalValue*>(Symb.p & ~uintptr_t(3));
 }
@@ -151,11 +153,11 @@
   return basic_symbol_iterator(BasicSymbolRef(Ret, this));
 }
 
-ErrorOr<SymbolicFile *> llvm::object::SymbolicFile::createIRObjectFile(
-    MemoryBuffer *Object, LLVMContext &Context, bool BufferOwned) {
+ErrorOr<SymbolicFile *>
+llvm::object::SymbolicFile::createIRObjectFile(MemoryBuffer *Object,
+                                               LLVMContext &Context) {
   std::error_code EC;
-  std::unique_ptr<IRObjectFile> Ret(
-      new IRObjectFile(Object, EC, Context, BufferOwned));
+  std::unique_ptr<IRObjectFile> Ret(new IRObjectFile(Object, EC, Context));
   if (EC)
     return EC;
   return Ret.release();
diff --git a/llvm/lib/Object/MachOObjectFile.cpp b/llvm/lib/Object/MachOObjectFile.cpp
index a072b0f..7fc02fb 100644
--- a/llvm/lib/Object/MachOObjectFile.cpp
+++ b/llvm/lib/Object/MachOObjectFile.cpp
@@ -423,9 +423,8 @@
 }
 
 MachOObjectFile::MachOObjectFile(MemoryBuffer *Object, bool IsLittleEndian,
-                                 bool Is64bits, std::error_code &EC,
-                                 bool BufferOwned)
-    : ObjectFile(getMachOType(IsLittleEndian, Is64bits), Object, BufferOwned),
+                                 bool Is64bits, std::error_code &EC)
+    : ObjectFile(getMachOType(IsLittleEndian, Is64bits), Object),
       SymtabLoadCmd(nullptr), DysymtabLoadCmd(nullptr),
       DataInCodeLoadCmd(nullptr) {
   uint32_t LoadCommandCount = this->getHeader().ncmds;
@@ -1812,19 +1811,18 @@
   }
 }
 
-ErrorOr<ObjectFile *> ObjectFile::createMachOObjectFile(MemoryBuffer *Buffer,
-                                                        bool BufferOwned) {
+ErrorOr<ObjectFile *> ObjectFile::createMachOObjectFile(MemoryBuffer *Buffer) {
   StringRef Magic = Buffer->getBuffer().slice(0, 4);
   std::error_code EC;
   std::unique_ptr<MachOObjectFile> Ret;
   if (Magic == "\xFE\xED\xFA\xCE")
-    Ret.reset(new MachOObjectFile(Buffer, false, false, EC, BufferOwned));
+    Ret.reset(new MachOObjectFile(Buffer, false, false, EC));
   else if (Magic == "\xCE\xFA\xED\xFE")
-    Ret.reset(new MachOObjectFile(Buffer, true, false, EC, BufferOwned));
+    Ret.reset(new MachOObjectFile(Buffer, true, false, EC));
   else if (Magic == "\xFE\xED\xFA\xCF")
-    Ret.reset(new MachOObjectFile(Buffer, false, true, EC, BufferOwned));
+    Ret.reset(new MachOObjectFile(Buffer, false, true, EC));
   else if (Magic == "\xCF\xFA\xED\xFE")
-    Ret.reset(new MachOObjectFile(Buffer, true, true, EC, BufferOwned));
+    Ret.reset(new MachOObjectFile(Buffer, true, true, EC));
   else {
     delete Buffer;
     return object_error::parse_failed;
diff --git a/llvm/lib/Object/ObjectFile.cpp b/llvm/lib/Object/ObjectFile.cpp
index 7666ed5..738ea5f 100644
--- a/llvm/lib/Object/ObjectFile.cpp
+++ b/llvm/lib/Object/ObjectFile.cpp
@@ -23,9 +23,8 @@
 
 void ObjectFile::anchor() { }
 
-ObjectFile::ObjectFile(unsigned int Type, MemoryBuffer *Source,
-                       bool BufferOwned)
-    : SymbolicFile(Type, Source, BufferOwned) {}
+ObjectFile::ObjectFile(unsigned int Type, MemoryBuffer *Source)
+    : SymbolicFile(Type, Source) {}
 
 std::error_code ObjectFile::printSymbolName(raw_ostream &OS,
                                             DataRefImpl Symb) const {
@@ -47,7 +46,6 @@
 }
 
 ErrorOr<ObjectFile *> ObjectFile::createObjectFile(MemoryBuffer *Object,
-                                                   bool BufferOwned,
                                                    sys::fs::file_magic Type) {
   if (Type == sys::fs::file_magic::unknown)
     Type = sys::fs::identify_magic(Object->getBuffer());
@@ -58,14 +56,12 @@
   case sys::fs::file_magic::archive:
   case sys::fs::file_magic::macho_universal_binary:
   case sys::fs::file_magic::windows_resource:
-    if (BufferOwned)
-      delete Object;
     return object_error::invalid_file_type;
   case sys::fs::file_magic::elf_relocatable:
   case sys::fs::file_magic::elf_executable:
   case sys::fs::file_magic::elf_shared_object:
   case sys::fs::file_magic::elf_core:
-    return createELFObjectFile(Object, BufferOwned);
+    return createELFObjectFile(Object);
   case sys::fs::file_magic::macho_object:
   case sys::fs::file_magic::macho_executable:
   case sys::fs::file_magic::macho_fixed_virtual_memory_shared_lib:
@@ -76,11 +72,11 @@
   case sys::fs::file_magic::macho_bundle:
   case sys::fs::file_magic::macho_dynamically_linked_shared_lib_stub:
   case sys::fs::file_magic::macho_dsym_companion:
-    return createMachOObjectFile(Object, BufferOwned);
+    return createMachOObjectFile(Object);
   case sys::fs::file_magic::coff_object:
   case sys::fs::file_magic::coff_import_library:
   case sys::fs::file_magic::pecoff_executable:
-    return createCOFFObjectFile(Object, BufferOwned);
+    return createCOFFObjectFile(Object);
   }
   llvm_unreachable("Unexpected Object File Type");
 }
diff --git a/llvm/lib/Object/SymbolicFile.cpp b/llvm/lib/Object/SymbolicFile.cpp
index 495f0b6..48fea02 100644
--- a/llvm/lib/Object/SymbolicFile.cpp
+++ b/llvm/lib/Object/SymbolicFile.cpp
@@ -19,15 +19,13 @@
 using namespace llvm;
 using namespace object;
 
-SymbolicFile::SymbolicFile(unsigned int Type, MemoryBuffer *Source,
-                           bool BufferOwned)
-    : Binary(Type, Source, BufferOwned) {}
+SymbolicFile::SymbolicFile(unsigned int Type, MemoryBuffer *Source)
+    : Binary(Type, Source) {}
 
 SymbolicFile::~SymbolicFile() {}
 
 ErrorOr<SymbolicFile *>
-SymbolicFile::createSymbolicFile(MemoryBuffer *Object, bool BufferOwned,
-                                 sys::fs::file_magic Type,
+SymbolicFile::createSymbolicFile(MemoryBuffer *Object, sys::fs::file_magic Type,
                                  LLVMContext *Context) {
   if (Type == sys::fs::file_magic::unknown)
     Type = sys::fs::identify_magic(Object->getBuffer());
@@ -35,14 +33,12 @@
   switch (Type) {
   case sys::fs::file_magic::bitcode:
     if (Context)
-      return IRObjectFile::createIRObjectFile(Object, *Context, BufferOwned);
+      return IRObjectFile::createIRObjectFile(Object, *Context);
   // Fallthrough
   case sys::fs::file_magic::unknown:
   case sys::fs::file_magic::archive:
   case sys::fs::file_magic::macho_universal_binary:
   case sys::fs::file_magic::windows_resource:
-    if (BufferOwned)
-      delete Object;
     return object_error::invalid_file_type;
   case sys::fs::file_magic::elf_relocatable:
   case sys::fs::file_magic::elf_executable:
@@ -61,7 +57,7 @@
   case sys::fs::file_magic::coff_object:
   case sys::fs::file_magic::coff_import_library:
   case sys::fs::file_magic::pecoff_executable:
-    return ObjectFile::createObjectFile(Object, BufferOwned, Type);
+    return ObjectFile::createObjectFile(Object, Type);
   }
   llvm_unreachable("Unexpected Binary File Type");
 }