1 //===- MemoryBufferCache.cpp - Cache for loaded memory buffers ------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "clang/Basic/MemoryBufferCache.h"
11 #include "llvm/Support/MemoryBuffer.h"
12 
13 using namespace clang;
14 
15 llvm::MemoryBuffer &
addBuffer(llvm::StringRef Filename,std::unique_ptr<llvm::MemoryBuffer> Buffer)16 MemoryBufferCache::addBuffer(llvm::StringRef Filename,
17                              std::unique_ptr<llvm::MemoryBuffer> Buffer) {
18   auto Insertion =
19       Buffers.insert({Filename, BufferEntry{std::move(Buffer), NextIndex++}});
20   assert(Insertion.second && "Already has a buffer");
21   return *Insertion.first->second.Buffer;
22 }
23 
lookupBuffer(llvm::StringRef Filename)24 llvm::MemoryBuffer *MemoryBufferCache::lookupBuffer(llvm::StringRef Filename) {
25   auto I = Buffers.find(Filename);
26   if (I == Buffers.end())
27     return nullptr;
28   return I->second.Buffer.get();
29 }
30 
isBufferFinal(llvm::StringRef Filename)31 bool MemoryBufferCache::isBufferFinal(llvm::StringRef Filename) {
32   auto I = Buffers.find(Filename);
33   if (I == Buffers.end())
34     return false;
35   return I->second.Index < FirstRemovableIndex;
36 }
37 
tryToRemoveBuffer(llvm::StringRef Filename)38 bool MemoryBufferCache::tryToRemoveBuffer(llvm::StringRef Filename) {
39   auto I = Buffers.find(Filename);
40   assert(I != Buffers.end() && "No buffer to remove...");
41   if (I->second.Index < FirstRemovableIndex)
42     return true;
43 
44   Buffers.erase(I);
45   return false;
46 }
47 
finalizeCurrentBuffers()48 void MemoryBufferCache::finalizeCurrentBuffers() { FirstRemovableIndex = NextIndex; }
49