1
0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-11-24 19:52:54 +01:00
llvm-mirror/lib/LTO/Caching.cpp
Peter Collingbourne 779a2cdb0a LTO: Improve error reporting when adding a cache entry.
Move error handling code next to the code that returns the error,
and change the error message in order to distinguish it from a similar
error message elsewhere in this file.

llvm-svn: 314745
2017-10-03 00:44:21 +00:00

104 lines
4.1 KiB
C++

//===-Caching.cpp - LLVM Link Time Optimizer Cache Handling ---------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the Caching for ThinLTO.
//
//===----------------------------------------------------------------------===//
#include "llvm/LTO/Caching.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/Support/Errc.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
using namespace llvm::lto;
Expected<NativeObjectCache> lto::localCache(StringRef CacheDirectoryPath,
AddBufferFn AddBuffer) {
if (std::error_code EC = sys::fs::create_directories(CacheDirectoryPath))
return errorCodeToError(EC);
return [=](unsigned Task, StringRef Key) -> AddStreamFn {
// This choice of file name allows the cache to be pruned (see pruneCache()
// in include/llvm/Support/CachePruning.h).
SmallString<64> EntryPath;
sys::path::append(EntryPath, CacheDirectoryPath, "llvmcache-" + Key);
// First, see if we have a cache hit.
ErrorOr<std::unique_ptr<MemoryBuffer>> MBOrErr =
MemoryBuffer::getFile(EntryPath);
if (MBOrErr) {
AddBuffer(Task, std::move(*MBOrErr), EntryPath);
return AddStreamFn();
}
if (MBOrErr.getError() != errc::no_such_file_or_directory)
report_fatal_error(Twine("Failed to open cache file ") + EntryPath +
": " + MBOrErr.getError().message() + "\n");
// This native object stream is responsible for commiting the resulting
// file to the cache and calling AddBuffer to add it to the link.
struct CacheStream : NativeObjectStream {
AddBufferFn AddBuffer;
std::string TempFilename;
std::string EntryPath;
unsigned Task;
CacheStream(std::unique_ptr<raw_pwrite_stream> OS, AddBufferFn AddBuffer,
std::string TempFilename, std::string EntryPath,
unsigned Task)
: NativeObjectStream(std::move(OS)), AddBuffer(std::move(AddBuffer)),
TempFilename(std::move(TempFilename)),
EntryPath(std::move(EntryPath)), Task(Task) {}
~CacheStream() {
// Make sure the file is closed before committing it.
OS.reset();
// Open the file first to avoid racing with a cache pruner.
ErrorOr<std::unique_ptr<MemoryBuffer>> MBOrErr =
MemoryBuffer::getFile(TempFilename);
if (!MBOrErr)
report_fatal_error(Twine("Failed to open new cache file ") +
TempFilename + ": " +
MBOrErr.getError().message() + "\n");
// This is atomic on POSIX systems.
if (auto EC = sys::fs::rename(TempFilename, EntryPath))
report_fatal_error(Twine("Failed to rename temporary file ") +
TempFilename + " to " + EntryPath + ": " +
EC.message() + "\n");
AddBuffer(Task, std::move(*MBOrErr), EntryPath);
}
};
return [=](size_t Task) -> std::unique_ptr<NativeObjectStream> {
// Write to a temporary to avoid race condition
int TempFD;
SmallString<64> TempFilenameModel, TempFilename;
sys::path::append(TempFilenameModel, CacheDirectoryPath, "Thin-%%%%%%.tmp.o");
std::error_code EC =
sys::fs::createUniqueFile(TempFilenameModel, TempFD, TempFilename,
sys::fs::owner_read | sys::fs::owner_write);
if (EC) {
errs() << "Error: " << EC.message() << "\n";
report_fatal_error("ThinLTO: Can't get a temporary file");
}
// This CacheStream will move the temporary file into the cache when done.
return llvm::make_unique<CacheStream>(
llvm::make_unique<raw_fd_ostream>(TempFD, /* ShouldClose */ true),
AddBuffer, TempFilename.str(), EntryPath.str(), Task);
};
};
}