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Diffstat (limited to 'gnu/llvm/lib/Support/FileOutputBuffer.cpp')
| -rw-r--r-- | gnu/llvm/lib/Support/FileOutputBuffer.cpp | 193 |
1 files changed, 0 insertions, 193 deletions
diff --git a/gnu/llvm/lib/Support/FileOutputBuffer.cpp b/gnu/llvm/lib/Support/FileOutputBuffer.cpp deleted file mode 100644 index b8223126227..00000000000 --- a/gnu/llvm/lib/Support/FileOutputBuffer.cpp +++ /dev/null @@ -1,193 +0,0 @@ -//===- FileOutputBuffer.cpp - File Output Buffer ----------------*- C++ -*-===// -// -// The LLVM Compiler Infrastructure -// -// This file is distributed under the University of Illinois Open Source -// License. See LICENSE.TXT for details. -// -//===----------------------------------------------------------------------===// -// -// Utility for creating a in-memory buffer that will be written to a file. -// -//===----------------------------------------------------------------------===// - -#include "llvm/Support/FileOutputBuffer.h" -#include "llvm/ADT/STLExtras.h" -#include "llvm/ADT/SmallString.h" -#include "llvm/Support/Errc.h" -#include "llvm/Support/Memory.h" -#include "llvm/Support/Path.h" -#include <system_error> - -#if !defined(_MSC_VER) && !defined(__MINGW32__) -#include <unistd.h> -#else -#include <io.h> -#endif - -using namespace llvm; -using namespace llvm::sys; - -namespace { -// A FileOutputBuffer which creates a temporary file in the same directory -// as the final output file. The final output file is atomically replaced -// with the temporary file on commit(). -class OnDiskBuffer : public FileOutputBuffer { -public: - OnDiskBuffer(StringRef Path, fs::TempFile Temp, - std::unique_ptr<fs::mapped_file_region> Buf) - : FileOutputBuffer(Path), Buffer(std::move(Buf)), Temp(std::move(Temp)) {} - - uint8_t *getBufferStart() const override { return (uint8_t *)Buffer->data(); } - - uint8_t *getBufferEnd() const override { - return (uint8_t *)Buffer->data() + Buffer->size(); - } - - size_t getBufferSize() const override { return Buffer->size(); } - - Error commit() override { - // Unmap buffer, letting OS flush dirty pages to file on disk. - Buffer.reset(); - - // Atomically replace the existing file with the new one. - return Temp.keep(FinalPath); - } - - ~OnDiskBuffer() override { - // Close the mapping before deleting the temp file, so that the removal - // succeeds. - Buffer.reset(); - consumeError(Temp.discard()); - } - - void discard() override { - // Delete the temp file if it still was open, but keeping the mapping - // active. - consumeError(Temp.discard()); - } - -private: - std::unique_ptr<fs::mapped_file_region> Buffer; - fs::TempFile Temp; -}; - -// A FileOutputBuffer which keeps data in memory and writes to the final -// output file on commit(). This is used only when we cannot use OnDiskBuffer. -class InMemoryBuffer : public FileOutputBuffer { -public: - InMemoryBuffer(StringRef Path, MemoryBlock Buf, unsigned Mode) - : FileOutputBuffer(Path), Buffer(Buf), Mode(Mode) {} - - uint8_t *getBufferStart() const override { return (uint8_t *)Buffer.base(); } - - uint8_t *getBufferEnd() const override { - return (uint8_t *)Buffer.base() + Buffer.size(); - } - - size_t getBufferSize() const override { return Buffer.size(); } - - Error commit() override { - using namespace sys::fs; - int FD; - std::error_code EC; - if (auto EC = - openFileForWrite(FinalPath, FD, CD_CreateAlways, OF_None, Mode)) - return errorCodeToError(EC); - raw_fd_ostream OS(FD, /*shouldClose=*/true, /*unbuffered=*/true); - OS << StringRef((const char *)Buffer.base(), Buffer.size()); - return Error::success(); - } - -private: - OwningMemoryBlock Buffer; - unsigned Mode; -}; -} // namespace - -static Expected<std::unique_ptr<InMemoryBuffer>> -createInMemoryBuffer(StringRef Path, size_t Size, unsigned Mode) { - std::error_code EC; - MemoryBlock MB = Memory::allocateMappedMemory( - Size, nullptr, sys::Memory::MF_READ | sys::Memory::MF_WRITE, EC); - if (EC) - return errorCodeToError(EC); - return llvm::make_unique<InMemoryBuffer>(Path, MB, Mode); -} - -static Expected<std::unique_ptr<OnDiskBuffer>> -createOnDiskBuffer(StringRef Path, size_t Size, bool InitExisting, - unsigned Mode) { - Expected<fs::TempFile> FileOrErr = - fs::TempFile::create(Path + ".tmp%%%%%%%", Mode); - if (!FileOrErr) - return FileOrErr.takeError(); - fs::TempFile File = std::move(*FileOrErr); - - if (InitExisting) { - if (auto EC = sys::fs::copy_file(Path, File.FD)) - return errorCodeToError(EC); - } else { -#ifndef _WIN32 - // On Windows, CreateFileMapping (the mmap function on Windows) - // automatically extends the underlying file. We don't need to - // extend the file beforehand. _chsize (ftruncate on Windows) is - // pretty slow just like it writes specified amount of bytes, - // so we should avoid calling that function. - if (auto EC = fs::resize_file(File.FD, Size)) { - consumeError(File.discard()); - return errorCodeToError(EC); - } -#endif - } - - // Mmap it. - std::error_code EC; - auto MappedFile = llvm::make_unique<fs::mapped_file_region>( - File.FD, fs::mapped_file_region::readwrite, Size, 0, EC); - if (EC) { - consumeError(File.discard()); - return errorCodeToError(EC); - } - return llvm::make_unique<OnDiskBuffer>(Path, std::move(File), - std::move(MappedFile)); -} - -// Create an instance of FileOutputBuffer. -Expected<std::unique_ptr<FileOutputBuffer>> -FileOutputBuffer::create(StringRef Path, size_t Size, unsigned Flags) { - unsigned Mode = fs::all_read | fs::all_write; - if (Flags & F_executable) - Mode |= fs::all_exe; - - fs::file_status Stat; - fs::status(Path, Stat); - - if ((Flags & F_modify) && Size == size_t(-1)) { - if (Stat.type() == fs::file_type::regular_file) - Size = Stat.getSize(); - else if (Stat.type() == fs::file_type::file_not_found) - return errorCodeToError(errc::no_such_file_or_directory); - else - return errorCodeToError(errc::invalid_argument); - } - - // Usually, we want to create OnDiskBuffer to create a temporary file in - // the same directory as the destination file and atomically replaces it - // by rename(2). - // - // However, if the destination file is a special file, we don't want to - // use rename (e.g. we don't want to replace /dev/null with a regular - // file.) If that's the case, we create an in-memory buffer, open the - // destination file and write to it on commit(). - switch (Stat.type()) { - case fs::file_type::directory_file: - return errorCodeToError(errc::is_a_directory); - case fs::file_type::regular_file: - case fs::file_type::file_not_found: - case fs::file_type::status_error: - return createOnDiskBuffer(Path, Size, !!(Flags & F_modify), Mode); - default: - return createInMemoryBuffer(Path, Size, Mode); - } -} |
