| //===- Buffer.cpp ---------------------------------------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "Buffer.h" |
| #include "llvm/Support/FileOutputBuffer.h" |
| #include "llvm/Support/FileSystem.h" |
| #include "llvm/Support/MemoryBuffer.h" |
| #include "llvm/Support/Process.h" |
| #include <memory> |
| |
| namespace llvm { |
| namespace objcopy { |
| |
| Buffer::~Buffer() {} |
| |
| static Error createEmptyFile(StringRef FileName) { |
| // Create an empty tempfile and atomically swap it in place with the desired |
| // output file. |
| Expected<sys::fs::TempFile> Temp = |
| sys::fs::TempFile::create(FileName + ".temp-empty-%%%%%%%"); |
| return Temp ? Temp->keep(FileName) : Temp.takeError(); |
| } |
| |
| Error FileBuffer::allocate(size_t Size) { |
| // When a 0-sized file is requested, skip allocation but defer file |
| // creation/truncation until commit() to avoid side effects if something |
| // happens between allocate() and commit(). |
| if (Size == 0) { |
| EmptyFile = true; |
| return Error::success(); |
| } |
| |
| Expected<std::unique_ptr<FileOutputBuffer>> BufferOrErr = |
| FileOutputBuffer::create(getName(), Size, |
| KeepOwnership |
| ? FileOutputBuffer::F_executable | |
| FileOutputBuffer::F_keep_ownership |
| : FileOutputBuffer::F_executable, |
| UserID, GroupID); |
| // FileOutputBuffer::create() returns an Error that is just a wrapper around |
| // std::error_code. Wrap it in FileError to include the actual filename. |
| if (!BufferOrErr) |
| return createFileError(getName(), BufferOrErr.takeError()); |
| Buf = std::move(*BufferOrErr); |
| return Error::success(); |
| } |
| |
| Error FileBuffer::commit() { |
| if (EmptyFile) |
| return createEmptyFile(getName()); |
| |
| assert(Buf && "allocate() not called before commit()!"); |
| Error Err = Buf->commit(); |
| // FileOutputBuffer::commit() returns an Error that is just a wrapper around |
| // std::error_code. Wrap it in FileError to include the actual filename. |
| return Err ? createFileError(getName(), std::move(Err)) : std::move(Err); |
| } |
| |
| uint8_t *FileBuffer::getBufferStart() { |
| return reinterpret_cast<uint8_t *>(Buf->getBufferStart()); |
| } |
| |
| Error MemBuffer::allocate(size_t Size) { |
| Buf = WritableMemoryBuffer::getNewMemBuffer(Size, getName()); |
| return Error::success(); |
| } |
| |
| 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 |