manmanren created this revision.
manmanren added reviewers: rsmith, benlangmuir, dexonsmith.
manmanren added subscribers: cfe-commits, bruno.
We create a PCMCache class to manage memory buffers associated with pcm files.
With implicit modules, we currently use lock files to make
sure we are making progress when a single clang invocation builds a module file
and then loads the module file immediately after. This
implementation requires lock file for correctness and causes all kinds of
locking issues.
This patch tries to use PCMCache to share the content between writes and reads
within a single clang invocation, so we can remove the
correctness-side of the lock file, and only use lock file for performance i.e
to reduce chance of building the same pcm file from multiple
clang invocations.
We also add ThreadContext in PCMCache to diagnose cases where an ancestor
validates a module and later on, a child thread tries
to invalidate it. Without the patch, this scenario will cause use-after-free of
the FileEntry held by the ancestor.
https://reviews.llvm.org/D28299
Files:
include/clang/Basic/DiagnosticSerializationKinds.td
include/clang/Basic/FileManager.h
include/clang/Serialization/ASTReader.h
include/clang/Serialization/ASTWriter.h
include/clang/Serialization/Module.h
include/clang/Serialization/ModuleManager.h
lib/Basic/FileManager.cpp
lib/Frontend/ASTUnit.cpp
lib/Frontend/ChainedIncludesSource.cpp
lib/Frontend/CompilerInstance.cpp
lib/Frontend/FrontendActions.cpp
lib/Serialization/ASTReader.cpp
lib/Serialization/ASTWriter.cpp
lib/Serialization/GeneratePCH.cpp
lib/Serialization/ModuleManager.cpp
Index: lib/Serialization/ModuleManager.cpp
===================================================================
--- lib/Serialization/ModuleManager.cpp
+++ lib/Serialization/ModuleManager.cpp
@@ -108,7 +108,11 @@
// Load the contents of the module
if (std::unique_ptr<llvm::MemoryBuffer> Buffer = lookupBuffer(FileName)) {
// The buffer was already provided for us.
- ModuleEntry->Buffer = std::move(Buffer);
+ ModuleEntry->Buffer = Buffer.get();
+ FileMgr.getPCMCache()->addConsistentBuffer(FileName, std::move(Buffer));
+ } else if(llvm::MemoryBuffer *ConsistentB =
+ FileMgr.getPCMCache()->lookupConsistentBuffer(FileName)) {
+ ModuleEntry->Buffer = ConsistentB;
} else {
// Open the AST file.
llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> Buf(
@@ -131,7 +135,8 @@
return Missing;
}
- ModuleEntry->Buffer = std::move(*Buf);
+ ModuleEntry->Buffer = (*Buf).get();
+ FileMgr.getPCMCache()->addConsistentBuffer(FileName, std::move(*Buf));
}
// Initialize the stream.
@@ -148,8 +153,11 @@
ErrorStr = ModuleEntry->Signature != ASTFileSignature({{0}}) ?
"signature mismatch" : "could not read module signature";
- if (NewModule)
+ if (NewModule) {
+ FileMgr.getPCMCache()->removeFromConsistentBuffer(
+ ModuleEntry->FileName);
delete ModuleEntry;
+ }
return OutOfDate;
}
}
@@ -184,7 +192,8 @@
void ModuleManager::removeModules(
ModuleIterator first, ModuleIterator last,
llvm::SmallPtrSetImpl<ModuleFile *> &LoadedSuccessfully,
- ModuleMap *modMap) {
+ ModuleMap *modMap,
+ llvm::SmallVectorImpl<std::string> &ValidationConflicts) {
if (first == last)
return;
@@ -227,16 +236,76 @@
// Files that didn't make it through ReadASTCore successfully will be
// rebuilt (or there was an error). Invalidate them so that we can load the
// new files that will be renamed over the old ones.
- if (LoadedSuccessfully.count(*victim) == 0)
- FileMgr.invalidateCache((*victim)->File);
-
+ if (LoadedSuccessfully.count(*victim) == 0) {
+ // Before removing the module file, check if it was validated in an
+ // ancestor thread, if yes, throw a hard error instead of causing
+ // use-after-free in the ancestor thread.
+ bool IsSystem;
+ if (FileMgr.getPCMCache()->isValidatedByAncestor((*victim)->FileName,
+ IsSystem))
+ ValidationConflicts.push_back((*victim)->FileName);
+ else
+ FileMgr.invalidateCache((*victim)->File);
+ FileMgr.getPCMCache()->removeFromConsistentBuffer((*victim)->FileName);
+ }
delete *victim;
}
// Remove the modules from the chain.
Chain.erase(first, last);
}
+llvm::MemoryBuffer*
+PCMCache::lookupConsistentBuffer(std::string Name) {
+ if (!ConsistentBuffers.count(Name))
+ return nullptr;
+ return ConsistentBuffers[Name].first.get();
+}
+
+void
+PCMCache::addConsistentBuffer(std::string FileName,
+ std::unique_ptr<llvm::MemoryBuffer> Buffer) {
+ assert(!ConsistentBuffers.count(FileName) && "already has a buffer");
+ ConsistentBuffers[FileName] = std::make_pair(std::move(Buffer),
+ /*IsSystem*/false);
+}
+
+void PCMCache::removeFromConsistentBuffer(std::string FileName) {
+ assert(ConsistentBuffers.count(FileName) && "remove a non-existent buffer");
+
+ // This should release the memory.
+ ConsistentBuffers.erase(FileName);
+}
+
+bool PCMCache::isValidatedByAncestor(std::string FileName, bool &IsSystem) {
+ IsSystem = false;
+ if (NestedThreadContexts.empty())
+ return false;
+ if (NestedThreadContexts.back().ModulesInParent.count(FileName)) {
+ IsSystem = NestedThreadContexts.back().ModulesInParent[FileName];
+ return true;
+ }
+ return false;
+}
+
+void PCMCache::setIsSystem(std::string FileName, bool IsSystem) {
+ assert(ConsistentBuffers.count(FileName) &&
+ "set IsSystem for a non-existent buffer");
+ ConsistentBuffers[FileName].second = IsSystem;
+}
+
+void PCMCache::StartThread() {
+ // Save all validated module files in thread context.
+ ThreadContext ThreadC;
+ for (auto &p : ConsistentBuffers)
+ ThreadC.ModulesInParent.insert(std::make_pair(p.first, p.second.second));
+ NestedThreadContexts.push_back(ThreadC);
+}
+
+void PCMCache::EndThread() {
+ NestedThreadContexts.pop_back();
+}
+
void
ModuleManager::addInMemoryBuffer(StringRef FileName,
std::unique_ptr<llvm::MemoryBuffer> Buffer) {
@@ -281,7 +350,8 @@
}
}
-void ModuleManager::moduleFileAccepted(ModuleFile *MF) {
+void ModuleManager::moduleFileAccepted(ModuleFile *MF, bool IsSystem) {
+ FileMgr.getPCMCache()->setIsSystem(MF->FileName, IsSystem);
if (!GlobalIndex || GlobalIndex->loadedModuleFile(MF))
return;
Index: lib/Serialization/GeneratePCH.cpp
===================================================================
--- lib/Serialization/GeneratePCH.cpp
+++ lib/Serialization/GeneratePCH.cpp
@@ -23,12 +23,12 @@
PCHGenerator::PCHGenerator(
const Preprocessor &PP, StringRef OutputFile, StringRef isysroot,
- std::shared_ptr<PCHBuffer> Buffer,
+ std::shared_ptr<PCHBuffer> Buffer, PCMCache *BufferMgr,
ArrayRef<llvm::IntrusiveRefCntPtr<ModuleFileExtension>> Extensions,
bool AllowASTWithErrors, bool IncludeTimestamps)
: PP(PP), OutputFile(OutputFile), isysroot(isysroot.str()),
SemaPtr(nullptr), Buffer(Buffer), Stream(Buffer->Data),
- Writer(Stream, Buffer->Data, Extensions, IncludeTimestamps),
+ Writer(Stream, Buffer->Data, BufferMgr, Extensions, IncludeTimestamps),
AllowASTWithErrors(AllowASTWithErrors) {
Buffer->IsComplete = false;
}
Index: lib/Serialization/ASTWriter.cpp
===================================================================
--- lib/Serialization/ASTWriter.cpp
+++ lib/Serialization/ASTWriter.cpp
@@ -4217,9 +4217,11 @@
ASTWriter::ASTWriter(
llvm::BitstreamWriter &Stream, SmallVectorImpl<char> &Buffer,
+ PCMCache *BufferMgr,
ArrayRef<llvm::IntrusiveRefCntPtr<ModuleFileExtension>> Extensions,
bool IncludeTimestamps)
- : Stream(Stream), Buffer(Buffer), Context(nullptr), PP(nullptr), Chain(nullptr),
+ : Stream(Stream), Buffer(Buffer), BufferMgr(BufferMgr),
+ Context(nullptr), PP(nullptr), Chain(nullptr),
WritingModule(nullptr), IncludeTimestamps(IncludeTimestamps),
WritingAST(false), DoneWritingDeclsAndTypes(false),
ASTHasCompilerErrors(false), FirstDeclID(NUM_PREDEF_DECL_IDS),
@@ -4283,6 +4285,16 @@
this->BaseDirectory.clear();
WritingAST = false;
+ if (BufferMgr && SemaRef.Context.getLangOpts().ImplicitModules &&
+ WritingModule) {
+ // Construct MemoryBuffer and update buffer manager.
+ std::unique_ptr<llvm::MemoryBuffer> write_buffer =
+ llvm::MemoryBuffer::getMemBufferCopy(
+ StringRef(Buffer.begin(), Buffer.size()));
+ BufferMgr->addConsistentBuffer(OutputFile, std::move(write_buffer));
+ BufferMgr->setIsSystem(OutputFile,
+ WritingModule ? WritingModule->IsSystem : false);
+ }
return Signature;
}
Index: lib/Serialization/ASTReader.cpp
===================================================================
--- lib/Serialization/ASTReader.cpp
+++ lib/Serialization/ASTReader.cpp
@@ -461,19 +461,9 @@
return checkDiagnosticGroupMappings(StoredDiags, Diags, Complain);
}
-bool PCHValidator::ReadDiagnosticOptions(
- IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts, bool Complain) {
- DiagnosticsEngine &ExistingDiags = PP.getDiagnostics();
- IntrusiveRefCntPtr<DiagnosticIDs> DiagIDs(ExistingDiags.getDiagnosticIDs());
- IntrusiveRefCntPtr<DiagnosticsEngine> Diags(
- new DiagnosticsEngine(DiagIDs, DiagOpts.get()));
- // This should never fail, because we would have processed these options
- // before writing them to an ASTFile.
- ProcessWarningOptions(*Diags, *DiagOpts, /*Report*/false);
-
- ModuleManager &ModuleMgr = Reader.getModuleManager();
- assert(ModuleMgr.size() >= 1 && "what ASTFile is this then");
-
+/// Return the top import module if it is implicit, nullptr otherwise.
+static Module *getTopImportImplicitModule(ModuleManager &ModuleMgr,
+ Preprocessor &PP) {
// If the original import came from a file explicitly generated by the user,
// don't check the diagnostic mappings.
// FIXME: currently this is approximated by checking whether this is not a
@@ -485,17 +475,37 @@
while (!TopImport->ImportedBy.empty())
TopImport = TopImport->ImportedBy[0];
if (TopImport->Kind != MK_ImplicitModule)
- return false;
+ return nullptr;
StringRef ModuleName = TopImport->ModuleName;
assert(!ModuleName.empty() && "diagnostic options read before module name");
Module *M = PP.getHeaderSearchInfo().lookupModule(ModuleName);
assert(M && "missing module");
+ return M;
+}
+
+bool PCHValidator::ReadDiagnosticOptions(
+ IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts, bool Complain) {
+ DiagnosticsEngine &ExistingDiags = PP.getDiagnostics();
+ IntrusiveRefCntPtr<DiagnosticIDs> DiagIDs(ExistingDiags.getDiagnosticIDs());
+ IntrusiveRefCntPtr<DiagnosticsEngine> Diags(
+ new DiagnosticsEngine(DiagIDs, DiagOpts.get()));
+ // This should never fail, because we would have processed these options
+ // before writing them to an ASTFile.
+ ProcessWarningOptions(*Diags, *DiagOpts, /*Report*/false);
+
+ ModuleManager &ModuleMgr = Reader.getModuleManager();
+ assert(ModuleMgr.size() >= 1 && "what ASTFile is this then");
+
+ Module *TopM = getTopImportImplicitModule(ModuleMgr, PP);
+ if (!TopM)
+ return false;
// FIXME: if the diagnostics are incompatible, save a DiagnosticOptions that
// contains the union of their flags.
- return checkDiagnosticMappings(*Diags, ExistingDiags, M->IsSystem, Complain);
+ return checkDiagnosticMappings(*Diags, ExistingDiags, TopM->IsSystem,
+ Complain);
}
/// \brief Collect the macro definitions provided by the given preprocessor
@@ -2177,7 +2187,9 @@
if (ValidateDiagnosticOptions &&
!AllowCompatibleConfigurationMismatch &&
ParseDiagnosticOptions(Record, Complain, Listener))
- return OutOfDate;
+ // Continue checking signature even if the diagnostic options
+ // are out of date.
+ Result = OutOfDate;
break;
}
case SIGNATURE: {
@@ -3640,11 +3652,15 @@
for (const ImportedModule &IM : Loaded)
LoadedSet.insert(IM.Mod);
+ llvm::SmallVector<std::string, 4> ValidationConflicts;
ModuleMgr.removeModules(ModuleMgr.begin() + NumModules, ModuleMgr.end(),
LoadedSet,
Context.getLangOpts().Modules
? &PP.getHeaderSearchInfo().getModuleMap()
- : nullptr);
+ : nullptr,
+ ValidationConflicts);
+ for (auto N : ValidationConflicts)
+ Diag(diag::err_module_ancestor_conflict) << N;
// If we find that any modules are unusable, the global index is going
// to be out-of-date. Just remove it.
@@ -3719,7 +3735,8 @@
M != MEnd; ++M) {
ModuleFile &F = *M->Mod;
- ModuleMgr.moduleFileAccepted(&F);
+ Module *Mod = getTopImportImplicitModule(ModuleMgr, PP);
+ ModuleMgr.moduleFileAccepted(&F, Mod ? Mod->IsSystem : false);
// Set the import location.
F.DirectImportLoc = ImportLoc;
@@ -4020,6 +4037,22 @@
if (DisableValidation ||
(AllowConfigurationMismatch && Result == ConfigurationMismatch))
Result = Success;
+ else if (Result == OutOfDate && F.Kind == MK_ImplicitModule) {
+ // If this module was validated as a system module, and it is now a
+ // non-system module, emit a warning about ignoring differences in
+ // diagnostic options.
+ bool IsSystem;
+ if (BufferMgr->isValidatedByAncestor(F.FileName, IsSystem)) {
+ if (IsSystem) {
+ Module *M = getTopImportImplicitModule(ModuleMgr, PP);
+ assert(M && "missing module");
+ if (!M->IsSystem) {
+ Diag(diag::warn_module_system_bit_conflict) << F.FileName;
+ Result = Success;
+ }
+ }
+ }
+ }
}
if (Result == Success)
@@ -7155,7 +7188,7 @@
void ASTReader::getMemoryBufferSizes(MemoryBufferSizes &sizes) const {
for (ModuleConstIterator I = ModuleMgr.begin(),
E = ModuleMgr.end(); I != E; ++I) {
- if (llvm::MemoryBuffer *buf = (*I)->Buffer.get()) {
+ if (llvm::MemoryBuffer *buf = (*I)->Buffer) {
size_t bytes = buf->getBufferSize();
switch (buf->getBufferKind()) {
case llvm::MemoryBuffer::MemoryBuffer_Malloc:
@@ -8962,6 +8995,7 @@
FileMgr(PP.getFileManager()), PCHContainerRdr(PCHContainerRdr),
Diags(PP.getDiagnostics()), SemaObj(nullptr), PP(PP), Context(Context),
Consumer(nullptr), ModuleMgr(PP.getFileManager(), PCHContainerRdr),
+ BufferMgr(PP.getFileManager().getPCMCache()),
DummyIdResolver(PP),
ReadTimer(std::move(ReadTimer)),
PragmaMSStructState(-1),
Index: lib/Frontend/FrontendActions.cpp
===================================================================
--- lib/Frontend/FrontendActions.cpp
+++ lib/Frontend/FrontendActions.cpp
@@ -92,7 +92,8 @@
std::vector<std::unique_ptr<ASTConsumer>> Consumers;
Consumers.push_back(llvm::make_unique<PCHGenerator>(
CI.getPreprocessor(), OutputFile, Sysroot,
- Buffer, CI.getFrontendOpts().ModuleFileExtensions,
+ Buffer, CI.getFileManager().getPCMCache(),
+ CI.getFrontendOpts().ModuleFileExtensions,
/*AllowASTWithErrors*/false,
/*IncludeTimestamps*/
+CI.getFrontendOpts().IncludeTimestamps));
@@ -142,7 +143,8 @@
Consumers.push_back(llvm::make_unique<PCHGenerator>(
CI.getPreprocessor(), OutputFile, Sysroot,
- Buffer, CI.getFrontendOpts().ModuleFileExtensions,
+ Buffer, CI.getFileManager().getPCMCache(),
+ CI.getFrontendOpts().ModuleFileExtensions,
/*AllowASTWithErrors=*/false,
/*IncludeTimestamps=*/
+CI.getFrontendOpts().BuildingImplicitModule));
Index: lib/Frontend/CompilerInstance.cpp
===================================================================
--- lib/Frontend/CompilerInstance.cpp
+++ lib/Frontend/CompilerInstance.cpp
@@ -1063,7 +1063,9 @@
// Note that this module is part of the module build stack, so that we
// can detect cycles in the module graph.
+ // PCMCache is part of the FileManager, so it is shared among threads.
Instance.setFileManager(&ImportingInstance.getFileManager());
+ ImportingInstance.getFileManager().getPCMCache()->StartThread();
Instance.createSourceManager(Instance.getFileManager());
SourceManager &SourceMgr = Instance.getSourceManager();
SourceMgr.setModuleBuildStack(
@@ -1131,6 +1133,7 @@
ImportingInstance.setBuildGlobalModuleIndex(true);
}
+ ImportingInstance.getFileManager().getPCMCache()->EndThread();
return !Instance.getDiagnostics().hasErrorOccurred();
}
Index: lib/Frontend/ChainedIncludesSource.cpp
===================================================================
--- lib/Frontend/ChainedIncludesSource.cpp
+++ lib/Frontend/ChainedIncludesSource.cpp
@@ -162,7 +162,8 @@
ArrayRef<llvm::IntrusiveRefCntPtr<ModuleFileExtension>> Extensions;
auto consumer = llvm::make_unique<PCHGenerator>(
Clang->getPreprocessor(), "-", /*isysroot=*/"", Buffer,
- Extensions, /*AllowASTWithErrors=*/true);
+ Clang->getFileManager().getPCMCache(), Extensions,
+ /*AllowASTWithErrors=*/true);
Clang->getASTContext().setASTMutationListener(
consumer->GetASTMutationListener());
Clang->setASTConsumer(std::move(consumer));
Index: lib/Frontend/ASTUnit.cpp
===================================================================
--- lib/Frontend/ASTUnit.cpp
+++ lib/Frontend/ASTUnit.cpp
@@ -185,7 +185,7 @@
llvm::BitstreamWriter Stream;
ASTWriter Writer;
- ASTWriterData() : Stream(Buffer), Writer(Stream, Buffer, { }) { }
+ ASTWriterData() : Stream(Buffer), Writer(Stream, Buffer, nullptr, { }) { }
};
void ASTUnit::clearFileLevelDecls() {
@@ -923,9 +923,10 @@
public:
PrecompilePreambleConsumer(ASTUnit &Unit, PrecompilePreambleAction *Action,
- const Preprocessor &PP, StringRef isysroot,
+ const Preprocessor &PP, PCMCache *BufferMgr,
+ StringRef isysroot,
std::unique_ptr<raw_ostream> Out)
- : PCHGenerator(PP, "", isysroot, std::make_shared<PCHBuffer>(),
+ : PCHGenerator(PP, "", isysroot, std::make_shared<PCHBuffer>(), BufferMgr,
ArrayRef<llvm::IntrusiveRefCntPtr<ModuleFileExtension>>(),
/*AllowASTWithErrors=*/true),
Unit(Unit), Hash(Unit.getCurrentTopLevelHashValue()), Action(Action),
@@ -994,7 +995,8 @@
llvm::make_unique<MacroDefinitionTrackerPPCallbacks>(
Unit.getCurrentTopLevelHashValue()));
return llvm::make_unique<PrecompilePreambleConsumer>(
- Unit, this, CI.getPreprocessor(), Sysroot, std::move(OS));
+ Unit, this, CI.getPreprocessor(), CI.getFileManager().getPCMCache(),
+ Sysroot, std::move(OS));
}
static bool isNonDriverDiag(const StoredDiagnostic &StoredDiag) {
@@ -2519,7 +2521,7 @@
SmallString<128> Buffer;
llvm::BitstreamWriter Stream(Buffer);
- ASTWriter Writer(Stream, Buffer, { });
+ ASTWriter Writer(Stream, Buffer, nullptr, { });
return serializeUnit(Writer, Buffer, getSema(), hasErrors, OS);
}
Index: lib/Basic/FileManager.cpp
===================================================================
--- lib/Basic/FileManager.cpp
+++ lib/Basic/FileManager.cpp
@@ -59,6 +59,7 @@
// file system.
if (!FS)
this->FS = vfs::getRealFileSystem();
+ BufferMgr = llvm::make_unique<PCMCache>();
}
FileManager::~FileManager() = default;
Index: include/clang/Serialization/ModuleManager.h
===================================================================
--- include/clang/Serialization/ModuleManager.h
+++ include/clang/Serialization/ModuleManager.h
@@ -159,7 +159,7 @@
/// \brief Returns the in-memory (virtual file) buffer with the given name
std::unique_ptr<llvm::MemoryBuffer> lookupBuffer(StringRef Name);
-
+
/// \brief Number of modules loaded
unsigned size() const { return Chain.size(); }
@@ -223,7 +223,8 @@
/// \brief Remove the given set of modules.
void removeModules(ModuleIterator first, ModuleIterator last,
llvm::SmallPtrSetImpl<ModuleFile *> &LoadedSuccessfully,
- ModuleMap *modMap);
+ ModuleMap *modMap,
+ llvm::SmallVectorImpl<std::string> &ValidationConflicts);
/// \brief Add an in-memory buffer the list of known buffers
void addInMemoryBuffer(StringRef FileName,
@@ -233,8 +234,9 @@
void setGlobalIndex(GlobalModuleIndex *Index);
/// \brief Notification from the AST reader that the given module file
- /// has been "accepted", and will not (can not) be unloaded.
- void moduleFileAccepted(ModuleFile *MF);
+ /// has been "accepted", and will not (can not) be unloaded. The IsSystem
+ /// flag tells us whether the module file was validated as a system module.
+ void moduleFileAccepted(ModuleFile *MF, bool IsSystem);
/// \brief Visit each of the modules.
///
Index: include/clang/Serialization/Module.h
===================================================================
--- include/clang/Serialization/Module.h
+++ include/clang/Serialization/Module.h
@@ -164,7 +164,8 @@
/// \brief The memory buffer that stores the data associated with
/// this AST file.
- std::unique_ptr<llvm::MemoryBuffer> Buffer;
+ /// The memory buffer is owned by PCMCache.
+ llvm::MemoryBuffer *Buffer;
/// \brief The size of this file, in bits.
uint64_t SizeInBits;
Index: include/clang/Serialization/ASTWriter.h
===================================================================
--- include/clang/Serialization/ASTWriter.h
+++ include/clang/Serialization/ASTWriter.h
@@ -109,6 +109,9 @@
/// \brief The buffer associated with the bitstream.
const SmallVectorImpl<char> &Buffer;
+ /// \brief The PCM manager which manages memory buffers for pcm files.
+ PCMCache *BufferMgr;
+
/// \brief The ASTContext we're writing.
ASTContext *Context;
@@ -505,6 +508,7 @@
/// \brief Create a new precompiled header writer that outputs to
/// the given bitstream.
ASTWriter(llvm::BitstreamWriter &Stream, SmallVectorImpl<char> &Buffer,
+ PCMCache *BufferMgr,
ArrayRef<llvm::IntrusiveRefCntPtr<ModuleFileExtension>> Extensions,
bool IncludeTimestamps = true);
~ASTWriter() override;
@@ -944,7 +948,7 @@
PCHGenerator(
const Preprocessor &PP, StringRef OutputFile,
StringRef isysroot,
- std::shared_ptr<PCHBuffer> Buffer,
+ std::shared_ptr<PCHBuffer> Buffer, PCMCache *BufferMgr,
ArrayRef<llvm::IntrusiveRefCntPtr<ModuleFileExtension>> Extensions,
bool AllowASTWithErrors = false,
bool IncludeTimestamps = true);
Index: include/clang/Serialization/ASTReader.h
===================================================================
--- include/clang/Serialization/ASTReader.h
+++ include/clang/Serialization/ASTReader.h
@@ -405,6 +405,9 @@
/// \brief The module manager which manages modules and their dependencies
ModuleManager ModuleMgr;
+ /// \brief The PCM manager which manages memory buffers for pcm files.
+ PCMCache *BufferMgr;
+
/// \brief A dummy identifier resolver used to merge TU-scope declarations in
/// C, for the cases where we don't have a Sema object to provide a real
/// identifier resolver.
Index: include/clang/Basic/FileManager.h
===================================================================
--- include/clang/Basic/FileManager.h
+++ include/clang/Basic/FileManager.h
@@ -39,6 +39,7 @@
namespace clang {
class FileSystemStatCache;
+class PCMCache;
/// \brief Cached information about one directory (either on disk or in
/// the virtual file system).
@@ -171,6 +172,9 @@
/// or a directory) as virtual directories.
void addAncestorsAsVirtualDirs(StringRef Path);
+ /// Manage memory buffers associated with pcm files.
+ std::unique_ptr<PCMCache> BufferMgr;
+
public:
FileManager(const FileSystemOptions &FileSystemOpts,
IntrusiveRefCntPtr<vfs::FileSystem> FS = nullptr);
@@ -282,6 +286,50 @@
StringRef getCanonicalName(const DirectoryEntry *Dir);
void PrintStats() const;
+
+ /// Return the manager for memory buffers associated with pcm files.
+ PCMCache *getPCMCache() {
+ return BufferMgr.get();
+ }
+};
+
+/// This class manages memory buffers associated with pcm files. It also keeps
+/// track of the thread context when we start a thread to implicitly build
+/// a module.
+class PCMCache {
+ /// Map a pcm file to a MemoryBuffer and a boolean that tells us whether
+ // the pcm file is validated as a system module.
+ std::map<std::string, std::pair<std::unique_ptr<llvm::MemoryBuffer>, bool>>
+ ConsistentBuffers;
+
+ typedef std::map<std::string, bool> IsSystemMap;
+ /// When we start a thread, we push in a ThreadContext; when we end
+ /// a thread, we pop a ThreadContext.
+ struct ThreadContext {
+ /// Keep track of all module files that have been validated in this thread
+ /// and whether the module file is validated as a system module.
+ IsSystemMap ModulesInParent;
+ };
+ SmallVector<ThreadContext, 8> NestedThreadContexts;
+
+public:
+ /// Add a memory buffer for a pcm file to the manager.
+ void addConsistentBuffer(std::string FileName,
+ std::unique_ptr<llvm::MemoryBuffer> Buffer);
+ /// Remove a pcm file from the map.
+ void removeFromConsistentBuffer(std::string FileName);
+ /// Return the memory buffer for a given pcm file.
+ llvm::MemoryBuffer *lookupConsistentBuffer(std::string Name);
+ /// Update the IsSystem boolean flag in ConsistentBuffers.
+ void setIsSystem(std::string FileName, bool IsSystem);
+
+ /// Check if a pcm file was validated by an ancestor, if yes, return
+ /// whether it was validated as a system module.
+ bool isValidatedByAncestor(std::string FileName, bool &IsSystem);
+
+ void StartThread();
+ void EndThread();
+
};
} // end namespace clang
Index: include/clang/Basic/DiagnosticSerializationKinds.td
===================================================================
--- include/clang/Basic/DiagnosticSerializationKinds.td
+++ include/clang/Basic/DiagnosticSerializationKinds.td
@@ -125,6 +125,15 @@
"duplicate module file extension block name '%0'">,
InGroup<ModuleFileExtension>;
+def warn_module_system_bit_conflict : Warning<
+ "module file '%0' was validated as a system module, ignoring differences in "
+ "diagnostic options now it is a non-system module">,
+ InGroup<ModuleConflict>;
+
+def err_module_ancestor_conflict : Error<
+ "module file '%0' was validated in an ancestor thread, now it needs to "
+ "be invalidated">;
+
} // let CategoryName
} // let Component
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