1//===- InMemoryModuleCache.cpp - Cache for loaded memory buffers ----------===//
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-exception
6//
7//===----------------------------------------------------------------------===//
8
9#include "clang/Serialization/InMemoryModuleCache.h"
10#include "llvm/Support/MemoryBuffer.h"
11
12using namespace clang;
13
14InMemoryModuleCache::State
15InMemoryModuleCache::getPCMState(llvm::StringRef Filename) const {
16  auto I = PCMs.find(Filename);
17  if (I == PCMs.end())
18    return Unknown;
19  if (I->second.IsFinal)
20    return Final;
21  return I->second.Buffer ? Tentative : ToBuild;
22}
23
24llvm::MemoryBuffer &
25InMemoryModuleCache::addPCM(llvm::StringRef Filename,
26                            std::unique_ptr<llvm::MemoryBuffer> Buffer) {
27  auto Insertion = PCMs.insert(std::make_pair(Filename, std::move(Buffer)));
28  assert(Insertion.second && "Already has a PCM");
29  return *Insertion.first->second.Buffer;
30}
31
32llvm::MemoryBuffer &
33InMemoryModuleCache::addBuiltPCM(llvm::StringRef Filename,
34                                 std::unique_ptr<llvm::MemoryBuffer> Buffer) {
35  auto &PCM = PCMs[Filename];
36  assert(!PCM.IsFinal && "Trying to override finalized PCM?");
37  assert(!PCM.Buffer && "Trying to override tentative PCM?");
38  PCM.Buffer = std::move(Buffer);
39  PCM.IsFinal = true;
40  return *PCM.Buffer;
41}
42
43llvm::MemoryBuffer *
44InMemoryModuleCache::lookupPCM(llvm::StringRef Filename) const {
45  auto I = PCMs.find(Filename);
46  if (I == PCMs.end())
47    return nullptr;
48  return I->second.Buffer.get();
49}
50
51bool InMemoryModuleCache::isPCMFinal(llvm::StringRef Filename) const {
52  return getPCMState(Filename) == Final;
53}
54
55bool InMemoryModuleCache::shouldBuildPCM(llvm::StringRef Filename) const {
56  return getPCMState(Filename) == ToBuild;
57}
58
59bool InMemoryModuleCache::tryToDropPCM(llvm::StringRef Filename) {
60  auto I = PCMs.find(Filename);
61  assert(I != PCMs.end() && "PCM to remove is unknown...");
62
63  auto &PCM = I->second;
64  assert(PCM.Buffer && "PCM to remove is scheduled to be built...");
65
66  if (PCM.IsFinal)
67    return true;
68
69  PCM.Buffer.reset();
70  return false;
71}
72
73void InMemoryModuleCache::finalizePCM(llvm::StringRef Filename) {
74  auto I = PCMs.find(Filename);
75  assert(I != PCMs.end() && "PCM to finalize is unknown...");
76
77  auto &PCM = I->second;
78  assert(PCM.Buffer && "Trying to finalize a dropped PCM...");
79  PCM.IsFinal = true;
80}
81