mirror of
https://github.com/RPCS3/llvm-mirror.git
synced 2024-10-25 14:02:52 +02:00
939901ec68
It's also possible to just write "= nullptr", but there's some question of whether that's as readable, so I leave it up to authors to pick which they prefer for now. If we want to discuss standardizing on one or the other, we can do that at some point in the future. llvm-svn: 213438
103 lines
3.1 KiB
C++
103 lines
3.1 KiB
C++
//===- 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/Errc.h"
|
|
#include "llvm/Support/FileOutputBuffer.h"
|
|
#include "llvm/ADT/SmallVector.h"
|
|
#include "llvm/Support/raw_ostream.h"
|
|
#include <system_error>
|
|
|
|
using llvm::sys::fs::mapped_file_region;
|
|
|
|
namespace llvm {
|
|
FileOutputBuffer::FileOutputBuffer(mapped_file_region * R,
|
|
StringRef Path, StringRef TmpPath)
|
|
: Region(R)
|
|
, FinalPath(Path)
|
|
, TempPath(TmpPath) {
|
|
}
|
|
|
|
FileOutputBuffer::~FileOutputBuffer() {
|
|
sys::fs::remove(Twine(TempPath));
|
|
}
|
|
|
|
std::error_code
|
|
FileOutputBuffer::create(StringRef FilePath, size_t Size,
|
|
std::unique_ptr<FileOutputBuffer> &Result,
|
|
unsigned Flags) {
|
|
// If file already exists, it must be a regular file (to be mappable).
|
|
sys::fs::file_status Stat;
|
|
std::error_code EC = sys::fs::status(FilePath, Stat);
|
|
switch (Stat.type()) {
|
|
case sys::fs::file_type::file_not_found:
|
|
// If file does not exist, we'll create one.
|
|
break;
|
|
case sys::fs::file_type::regular_file: {
|
|
// If file is not currently writable, error out.
|
|
// FIXME: There is no sys::fs:: api for checking this.
|
|
// FIXME: In posix, you use the access() call to check this.
|
|
}
|
|
break;
|
|
default:
|
|
if (EC)
|
|
return EC;
|
|
else
|
|
return make_error_code(errc::operation_not_permitted);
|
|
}
|
|
|
|
// Delete target file.
|
|
EC = sys::fs::remove(FilePath);
|
|
if (EC)
|
|
return EC;
|
|
|
|
unsigned Mode = sys::fs::all_read | sys::fs::all_write;
|
|
// If requested, make the output file executable.
|
|
if (Flags & F_executable)
|
|
Mode |= sys::fs::all_exe;
|
|
|
|
// Create new file in same directory but with random name.
|
|
SmallString<128> TempFilePath;
|
|
int FD;
|
|
EC = sys::fs::createUniqueFile(Twine(FilePath) + ".tmp%%%%%%%", FD,
|
|
TempFilePath, Mode);
|
|
if (EC)
|
|
return EC;
|
|
|
|
std::unique_ptr<mapped_file_region> MappedFile(new mapped_file_region(
|
|
FD, true, mapped_file_region::readwrite, Size, 0, EC));
|
|
if (EC)
|
|
return EC;
|
|
|
|
Result.reset(new FileOutputBuffer(MappedFile.get(), FilePath, TempFilePath));
|
|
if (Result)
|
|
MappedFile.release();
|
|
|
|
return std::error_code();
|
|
}
|
|
|
|
std::error_code FileOutputBuffer::commit(int64_t NewSmallerSize) {
|
|
// Unmap buffer, letting OS flush dirty pages to file on disk.
|
|
Region.reset();
|
|
|
|
// If requested, resize file as part of commit.
|
|
if ( NewSmallerSize != -1 ) {
|
|
std::error_code EC = sys::fs::resize_file(Twine(TempPath), NewSmallerSize);
|
|
if (EC)
|
|
return EC;
|
|
}
|
|
|
|
// Rename file to final name.
|
|
return sys::fs::rename(Twine(TempPath), Twine(FinalPath));
|
|
}
|
|
} // namespace
|