Don't own the buffer in object::Binary.

Owning the buffer is somewhat inflexible. Some Binaries have sub Binaries
(like Archive) and we had to create dummy buffers just to handle that. It is
also a bad fit for IRObjectFile where the Module wants to own the buffer too.

Keeping this ownership would make supporting IR inside native objects
particularly painful.

This patch focuses in lib/Object. If something elsewhere used to own an Binary,
now it also owns a MemoryBuffer.

This patch introduces a few new types.

* MemoryBufferRef. This is just a pair of StringRefs for the data and name.
  This is to MemoryBuffer as StringRef is to std::string.
* OwningBinary. A combination of Binary and a MemoryBuffer. This is needed
  for convenience functions that take a filename and return both the
  buffer and the Binary using that buffer.

The C api now uses OwningBinary to avoid any change in semantics. I will start
a new thread to see if we want to change it and how.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216002 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 9 insertions, 13 deletions

diff --git a/lib/Object/MachOUniversal.cpp b/lib/Object/MachOUniversal.cpp
index ece652b4c09..8d24403d033 100644
--- a/lib/Object/MachOUniversal.cpp
+++ b/lib/Object/MachOUniversal.cpp
@@ -72,9 +72,8 @@ MachOUniversalBinary::ObjectForArch::getAsObjectFile() const {
   if (Parent) {
     StringRef ParentData = Parent->getData();
     StringRef ObjectData = ParentData.substr(Header.offset, Header.size);
-    std::string ObjectName = Parent->getFileName().str();
-    std::unique_ptr<MemoryBuffer> ObjBuffer(
-        MemoryBuffer::getMemBuffer(ObjectData, ObjectName, false));
+    StringRef ObjectName = Parent->getFileName().str();
+    MemoryBufferRef ObjBuffer(ObjectData, ObjectName);
     return ObjectFile::createMachOObjectFile(ObjBuffer);
   }
   return object_error::parse_failed;
@@ -86,10 +85,8 @@ std::error_code MachOUniversalBinary::ObjectForArch::getAsArchive(
     StringRef ParentData = Parent->getData();
     StringRef ObjectData = ParentData.substr(Header.offset, Header.size);
     std::string ObjectName = Parent->getFileName().str();
-    std::unique_ptr<MemoryBuffer> ObjBuffer(
-        MemoryBuffer::getMemBuffer(ObjectData, ObjectName, false));
-    ErrorOr<std::unique_ptr<Archive>> Obj =
-        Archive::create(std::move(ObjBuffer));
+    MemoryBufferRef ObjBuffer(ObjectData, ObjectName);
+    ErrorOr<std::unique_ptr<Archive>> Obj = Archive::create(ObjBuffer);
     if (std::error_code EC = Obj.getError())
       return EC;
     Result = std::move(Obj.get());
@@ -101,20 +98,19 @@ std::error_code MachOUniversalBinary::ObjectForArch::getAsArchive(
 void MachOUniversalBinary::anchor() { }
 
 ErrorOr<MachOUniversalBinary *>
-MachOUniversalBinary::create(std::unique_ptr<MemoryBuffer> Source) {
+MachOUniversalBinary::create(MemoryBufferRef Source) {
   std::error_code EC;
   std::unique_ptr<MachOUniversalBinary> Ret(
-      new MachOUniversalBinary(std::move(Source), EC));
+      new MachOUniversalBinary(Source, EC));
   if (EC)
     return EC;
   return Ret.release();
 }
 
-MachOUniversalBinary::MachOUniversalBinary(std::unique_ptr<MemoryBuffer> Source,
+MachOUniversalBinary::MachOUniversalBinary(MemoryBufferRef Source,
                                            std::error_code &ec)
-    : Binary(Binary::ID_MachOUniversalBinary, std::move(Source)),
-      NumberOfObjects(0) {
-  if (Data->getBufferSize() < sizeof(MachO::fat_header)) {
+    : Binary(Binary::ID_MachOUniversalBinary, Source), NumberOfObjects(0) {
+  if (Data.getBufferSize() < sizeof(MachO::fat_header)) {
     ec = object_error::invalid_file_type;
     return;
   }