111 lines · cpp
1//===----------------------------------------------------------------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8///9/// \file10/// This file implements \c OutputFile class methods.11///12//===----------------------------------------------------------------------===//13 14#include "llvm/Support/VirtualOutputFile.h"15#include "llvm/Support/VirtualOutputError.h"16#include "llvm/Support/raw_ostream.h"17#include "llvm/Support/raw_ostream_proxy.h"18 19using namespace llvm;20using namespace llvm::vfs;21 22char OutputFileImpl::ID = 0;23char NullOutputFileImpl::ID = 0;24 25void OutputFileImpl::anchor() {}26void NullOutputFileImpl::anchor() {}27 28class OutputFile::TrackedProxy : public raw_pwrite_stream_proxy {29public:30 void resetProxy() {31 TrackingPointer = nullptr;32 resetProxiedOS();33 }34 35 explicit TrackedProxy(TrackedProxy *&TrackingPointer, raw_pwrite_stream &OS)36 : raw_pwrite_stream_proxy(OS), TrackingPointer(TrackingPointer) {37 assert(!TrackingPointer && "Expected to add a proxy");38 TrackingPointer = this;39 }40 41 ~TrackedProxy() override { resetProxy(); }42 43 TrackedProxy *&TrackingPointer;44};45 46Expected<std::unique_ptr<raw_pwrite_stream>> OutputFile::createProxy() {47 if (OpenProxy)48 return make_error<OutputError>(getPath(), OutputErrorCode::has_open_proxy);49 50 return std::make_unique<TrackedProxy>(OpenProxy, getOS());51}52 53Error OutputFile::keep() {54 // Catch double-closing logic bugs.55 if (LLVM_UNLIKELY(!Impl))56 report_fatal_error(57 make_error<OutputError>(getPath(), OutputErrorCode::already_closed));58 59 // Report a fatal error if there's an open proxy and the file is being kept.60 // This is safer than relying on clients to remember to flush(). Also call61 // OutputFile::discard() to give the backend a chance to clean up any62 // side effects (such as temporaries).63 if (LLVM_UNLIKELY(OpenProxy))64 report_fatal_error(joinErrors(65 make_error<OutputError>(getPath(), OutputErrorCode::has_open_proxy),66 discard()));67 68 Error E = Impl->keep();69 Impl = nullptr;70 DiscardOnDestroyHandler = nullptr;71 return E;72}73 74Error OutputFile::discard() {75 // Catch double-closing logic bugs.76 if (LLVM_UNLIKELY(!Impl))77 report_fatal_error(78 make_error<OutputError>(getPath(), OutputErrorCode::already_closed));79 80 // Be lenient about open proxies since client teardown paths won't81 // necessarily clean up in the right order. Reset the proxy to flush any82 // current content; if there is another write, there should be quick crash on83 // null dereference.84 if (OpenProxy)85 OpenProxy->resetProxy();86 87 Error E = Impl->discard();88 Impl = nullptr;89 DiscardOnDestroyHandler = nullptr;90 return E;91}92 93void OutputFile::destroy() {94 if (!Impl)95 return;96 97 // Clean up the file. Move the discard handler into a local since discard98 // will reset it.99 auto DiscardHandler = std::move(DiscardOnDestroyHandler);100 Error E = discard();101 assert(!Impl && "Expected discard to destroy Impl");102 103 // If there's no handler, report a fatal error.104 if (LLVM_UNLIKELY(!DiscardHandler))105 llvm::report_fatal_error(joinErrors(106 make_error<OutputError>(getPath(), OutputErrorCode::not_closed),107 std::move(E)));108 else if (E)109 DiscardHandler(std::move(E));110}111