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authorDimitry Andric <dim@FreeBSD.org>2019-12-20 19:53:05 +0000
committerDimitry Andric <dim@FreeBSD.org>2019-12-20 19:53:05 +0000
commit0b57cec536236d46e3dba9bd041533462f33dbb7 (patch)
tree56229dbdbbf76d18580f72f789003db17246c8d9 /contrib/llvm/lib/Support/FileOutputBuffer.cpp
parent718ef55ec7785aae63f98f8ca05dc07ed399c16d (diff)
Notes
Diffstat (limited to 'contrib/llvm/lib/Support/FileOutputBuffer.cpp')
-rw-r--r--contrib/llvm/lib/Support/FileOutputBuffer.cpp196
1 files changed, 0 insertions, 196 deletions
diff --git a/contrib/llvm/lib/Support/FileOutputBuffer.cpp b/contrib/llvm/lib/Support/FileOutputBuffer.cpp
deleted file mode 100644
index 3d6b569f2993..000000000000
--- a/contrib/llvm/lib/Support/FileOutputBuffer.cpp
+++ /dev/null
@@ -1,196 +0,0 @@
-//===- FileOutputBuffer.cpp - File Output Buffer ----------------*- C++ -*-===//
-//
-// 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
-//
-//===----------------------------------------------------------------------===//
-//
-// 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, std::size_t BufSize,
- unsigned Mode)
- : FileOutputBuffer(Path), Buffer(Buf), BufferSize(BufSize),
- Mode(Mode) {}
-
- uint8_t *getBufferStart() const override { return (uint8_t *)Buffer.base(); }
-
- uint8_t *getBufferEnd() const override {
- return (uint8_t *)Buffer.base() + BufferSize;
- }
-
- size_t getBufferSize() const override { return BufferSize; }
-
- Error commit() override {
- if (FinalPath == "-") {
- llvm::outs() << StringRef((const char *)Buffer.base(), BufferSize);
- llvm::outs().flush();
- return Error::success();
- }
-
- 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(), BufferSize);
- return Error::success();
- }
-
-private:
- // Buffer may actually contain a larger memory block than BufferSize
- OwningMemoryBlock Buffer;
- size_t BufferSize;
- 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, Size, Mode);
-}
-
-static Expected<std::unique_ptr<FileOutputBuffer>>
-createOnDiskBuffer(StringRef Path, size_t Size, unsigned Mode) {
- Expected<fs::TempFile> FileOrErr =
- fs::TempFile::create(Path + ".tmp%%%%%%%", Mode);
- if (!FileOrErr)
- return FileOrErr.takeError();
- fs::TempFile File = std::move(*FileOrErr);
-
-#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>(
- fs::convertFDToNativeFile(File.FD), fs::mapped_file_region::readwrite,
- Size, 0, EC);
-
- // mmap(2) can fail if the underlying filesystem does not support it.
- // If that happens, we fall back to in-memory buffer as the last resort.
- if (EC) {
- consumeError(File.discard());
- return createInMemoryBuffer(Path, Size, Mode);
- }
-
- 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) {
- // Handle "-" as stdout just like llvm::raw_ostream does.
- if (Path == "-")
- return createInMemoryBuffer("-", Size, /*Mode=*/0);
-
- unsigned Mode = fs::all_read | fs::all_write;
- if (Flags & F_executable)
- Mode |= fs::all_exe;
-
- fs::file_status Stat;
- fs::status(Path, Stat);
-
- // 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, Mode);
- default:
- return createInMemoryBuffer(Path, Size, Mode);
- }
-}