[Binary] Make the OffloadingImage type own the memory

Summary:
The OffloadingBinary uses a convenience struct to help manage the memory
that will be serialized using the binary format. This currently uses a
reference to an existing buffer, but this should own the memory instead
so it is easier to work with seeing as its only current use requires
saving the buffer anyway.

clang/tools/clang-offload-packager/ClangOffloadPackager.cpp

@@ -89,8 +89,7 @@ int main(int argc, const char **argv) {
             llvm::MemoryBuffer::getFileOrSTDIN(KeyAndValue.getValue());
         if (std::error_code EC = ObjectOrErr.getError())
           return reportError(errorCodeToError(EC));
-        DeviceImage = std::move(*ObjectOrErr);
-        ImageBinary.Image = *DeviceImage;
+        ImageBinary.Image = std::move(*ObjectOrErr);
         ImageBinary.TheImageKind = getImageKind(
             sys::path::extension(KeyAndValue.getValue()).drop_front());
       } else if (Key == "kind") {

llvm/include/llvm/Object/OffloadBinary.h

@@ -65,7 +65,7 @@ class OffloadBinary : public Binary {
     OffloadKind TheOffloadKind;
     uint32_t Flags;
     StringMap<StringRef> StringData;
-    MemoryBufferRef Image;
+    std::unique_ptr<MemoryBuffer> Image;
   };
 
   /// Attempt to parse the offloading binary stored in \p Data.

llvm/lib/Object/OffloadBinary.cpp

@@ -58,7 +58,7 @@ OffloadBinary::write(const OffloadingImage &OffloadingData) {
   // header so this can be placed contiguously in a single section.
   Header TheHeader;
   TheHeader.Size = alignTo(
-      BinaryDataSize + OffloadingData.Image.getBufferSize(), getAlignment());
+      BinaryDataSize + OffloadingData.Image->getBufferSize(), getAlignment());
   TheHeader.EntryOffset = sizeof(Header);
   TheHeader.EntrySize = sizeof(Entry);
 
@@ -72,7 +72,7 @@ OffloadBinary::write(const OffloadingImage &OffloadingData) {
   TheEntry.NumStrings = OffloadingData.StringData.size();
 
   TheEntry.ImageOffset = BinaryDataSize;
-  TheEntry.ImageSize = OffloadingData.Image.getBufferSize();
+  TheEntry.ImageSize = OffloadingData.Image->getBufferSize();
 
   SmallVector<char, 1024> Data;
   raw_svector_ostream OS(Data);
@@ -87,7 +87,7 @@ OffloadBinary::write(const OffloadingImage &OffloadingData) {
   StrTab.write(OS);
   // Add padding to required image alignment.
   OS.write_zeros(TheEntry.ImageOffset - OS.tell());
-  OS << OffloadingData.Image.getBuffer();
+  OS << OffloadingData.Image->getBuffer();
 
   // Add final padding to required alignment.
   assert(TheHeader.Size >= OS.tell() && "Too much data written?");

llvm/unittests/Object/OffloadingTest.cpp

@@ -41,7 +41,7 @@ TEST(OffloadingTest, checkOffloadingBinary) {
   Data.TheOffloadKind = static_cast<OffloadKind>(KindDist(Rng));
   Data.Flags = KindDist(Rng);
   Data.StringData = StringData;
-  Data.Image = *ImageData;
+  Data.Image = std::move(ImageData);
 
   auto BinaryBuffer = OffloadBinary::write(Data);
 
@@ -59,7 +59,7 @@ TEST(OffloadingTest, checkOffloadingBinary) {
     ASSERT_TRUE(StringData[KeyAndValue.first] ==
                 Binary.getString(KeyAndValue.first));
 
-  EXPECT_TRUE(Data.Image.getBuffer() == Binary.getImage());
+  EXPECT_TRUE(Data.Image->getBuffer() == Binary.getImage());
 
   // Ensure the size and alignment of the data is correct.
   EXPECT_TRUE(Binary.getSize() % OffloadBinary::getAlignment() == 0);