[llvm-objcopy] Factor out Buffer

In this diff we move out the hierarchy of buffers from Object.h/Object.cpp 
into separate files since it is not ELF-specific and will be reused later. 
After this change Object.h/Object.cpp are almost exclusively ELF-specific.

Test plan: make check-all

Differential revision: https://reviews.llvm.org/D53298

llvm-svn: 344585

1 files changed, 51 insertions, 0 deletions

diff --git a/llvm/tools/llvm-objcopy/Buffer.cpp b/llvm/tools/llvm-objcopy/Buffer.cpp
new file mode 100644
index 00000000000..8044b023aaa
--- /dev/null
+++ b/llvm/tools/llvm-objcopy/Buffer.cpp
@@ -0,0 +1,51 @@
+//===- Buffer.cpp ---------------------------------------------------------===//
+//
+//                      The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "Buffer.h"
+#include "llvm-objcopy.h"
+#include "llvm/Support/FileOutputBuffer.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include <memory>
+
+namespace llvm {
+namespace objcopy {
+
+Buffer::~Buffer() {}
+
+void FileBuffer::allocate(size_t Size) {
+  Expected<std::unique_ptr<FileOutputBuffer>> BufferOrErr =
+      FileOutputBuffer::create(getName(), Size, FileOutputBuffer::F_executable);
+  handleAllErrors(BufferOrErr.takeError(), [this](const ErrorInfoBase &E) {
+    error("failed to open " + getName() + ": " + E.message());
+  });
+  Buf = std::move(*BufferOrErr);
+}
+
+Error FileBuffer::commit() { return Buf->commit(); }
+
+uint8_t *FileBuffer::getBufferStart() {
+  return reinterpret_cast<uint8_t *>(Buf->getBufferStart());
+}
+
+void MemBuffer::allocate(size_t Size) {
+  Buf = WritableMemoryBuffer::getNewMemBuffer(Size, getName());
+}
+
+Error MemBuffer::commit() { return Error::success(); }
+
+uint8_t *MemBuffer::getBufferStart() {
+  return reinterpret_cast<uint8_t *>(Buf->getBufferStart());
+}
+
+std::unique_ptr<WritableMemoryBuffer> MemBuffer::releaseMemoryBuffer() {
+  return std::move(Buf);
+}
+
+} // end namespace objcopy
+} // end namespace llvm