//===--- ModuleManager.cpp - Module Manager ---------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines the ModuleManager class, which manages a set of loaded
// modules for the ASTReader.
//
//===----------------------------------------------------------------------===//
#include "clang/Serialization/ModuleManager.h"
#include "clang/Frontend/PCHContainerOperations.h"
#include "clang/Lex/HeaderSearch.h"
#include "clang/Lex/ModuleMap.h"
#include "clang/Serialization/GlobalModuleIndex.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/Path.h"
#include <system_error>
#ifndef NDEBUG
#include "llvm/Support/GraphWriter.h"
#endif
using namespace clang;
using namespace serialization;
ModuleFile *ModuleManager::lookup(StringRef Name) {
const FileEntry *Entry = FileMgr.getFile(Name, /*openFile=*/false,
/*cacheFailure=*/false);
if (Entry)
return lookup(Entry);
return nullptr;
}
ModuleFile *ModuleManager::lookup(const FileEntry *File) {
llvm::DenseMap<const FileEntry *, ModuleFile *>::iterator Known
= Modules.find(File);
if (Known == Modules.end())
return nullptr;
return Known->second;
}
std::unique_ptr<llvm::MemoryBuffer>
ModuleManager::lookupBuffer(StringRef Name) {
const FileEntry *Entry = FileMgr.getFile(Name, /*openFile=*/false,
/*cacheFailure=*/false);
return std::move(InMemoryBuffers[Entry]);
}
ModuleManager::AddModuleResult
ModuleManager::addModule(StringRef FileName, ModuleKind Type,
SourceLocation ImportLoc, ModuleFile *ImportedBy,
unsigned Generation,
off_t ExpectedSize, time_t ExpectedModTime,
ASTFileSignature ExpectedSignature,
ASTFileSignatureReader ReadSignature,
ModuleFile *&Module,
std::string &ErrorStr) {
Module = nullptr;
// Look for the file entry. This only fails if the expected size or
// modification time differ.
const FileEntry *Entry;
if (Type == MK_ExplicitModule || Type == MK_PrebuiltModule) {
// If we're not expecting to pull this file out of the module cache, it
// might have a different mtime due to being moved across filesystems in
// a distributed build. The size must still match, though. (As must the
// contents, but we can't check that.)
ExpectedModTime = 0;
}
if (lookupModuleFile(FileName, ExpectedSize, ExpectedModTime, Entry)) {
ErrorStr = "module file out of date";
return OutOfDate;
}
if (!Entry && FileName != "-") {
ErrorStr = "module file not found";
return Missing;
}
// Check whether we already loaded this module, before
ModuleFile *ModuleEntry = Modules[Entry];
bool NewModule = false;
if (!ModuleEntry) {
// Allocate a new module.
NewModule = true;
ModuleEntry = new ModuleFile(Type, Generation);
ModuleEntry->Index = Chain.size();
ModuleEntry->FileName = FileName.str();
ModuleEntry->File = Entry;
ModuleEntry->ImportLoc = ImportLoc;
ModuleEntry->InputFilesValidationTimestamp = 0;
if (ModuleEntry->Kind == MK_ImplicitModule) {
std::string TimestampFilename = ModuleEntry->getTimestampFilename();
vfs::Status Status;
// A cached stat value would be fine as well.
if (!FileMgr.getNoncachedStatValue(TimestampFilename, Status))
ModuleEntry->InputFilesValidationTimestamp =
llvm::sys::toTimeT(Status.getLastModificationTime());
}
// 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);
} else {
// Open the AST file.
llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> Buf(
(std::error_code()));
if (FileName == "-") {
Buf = llvm::MemoryBuffer::getSTDIN();
} else {
// Leave the FileEntry open so if it gets read again by another
// ModuleManager it must be the same underlying file.
// FIXME: Because FileManager::getFile() doesn't guarantee that it will
// give us an open file, this may not be 100% reliable.
Buf = FileMgr.getBufferForFile(ModuleEntry->File,
/*IsVolatile=*/false,
/*ShouldClose=*/false);
}
if (!Buf) {
ErrorStr = Buf.getError().message();
delete ModuleEntry;
return Missing;
}
ModuleEntry->Buffer = std::move(*Buf);
}
// Initialize the stream.
ModuleEntry->Data = PCHContainerRdr.ExtractPCH(*ModuleEntry->Buffer);
}
if (ExpectedSignature) {
// If we've not read the control block yet, read the signature eagerly now
// so that we can check it.
if (!ModuleEntry->Signature)
ModuleEntry->Signature = ReadSignature(ModuleEntry->Data);
if (ModuleEntry->Signature != ExpectedSignature) {
ErrorStr = ModuleEntry->Signature ? "signature mismatch"
: "could not read module signature";
if (NewModule)
delete ModuleEntry;
return OutOfDate;
}
}
if (ImportedBy) {
ModuleEntry->ImportedBy.insert(ImportedBy);
ImportedBy->Imports.insert(ModuleEntry);
} else {
if (!ModuleEntry->DirectlyImported)
ModuleEntry->ImportLoc = ImportLoc;
ModuleEntry->DirectlyImported = true;
}
Module = ModuleEntry;
if (!NewModule)
return AlreadyLoaded;
assert(!Modules[Entry] && "module loaded twice");
Modules[Entry] = ModuleEntry;
Chain.push_back(ModuleEntry);
if (!ModuleEntry->isModule())
PCHChain.push_back(ModuleEntry);
if (!ImportedBy)
Roots.push_back(ModuleEntry);
return NewlyLoaded;
}
void ModuleManager::removeModules(
ModuleIterator first, ModuleIterator last,
llvm::SmallPtrSetImpl<ModuleFile *> &LoadedSuccessfully,
ModuleMap *modMap) {
if (first == last)
return;
// Explicitly clear VisitOrder since we might not notice it is stale.
VisitOrder.clear();
// Collect the set of module file pointers that we'll be removing.
llvm::SmallPtrSet<ModuleFile *, 4> victimSet(first, last);
auto IsVictim = [&](ModuleFile *MF) {
return victimSet.count(MF);
};
// Remove any references to the now-destroyed modules.
for (unsigned i = 0, n = Chain.size(); i != n; ++i) {
Chain[i]->ImportedBy.remove_if(IsVictim);
}
Roots.erase(std::remove_if(Roots.begin(), Roots.end(), IsVictim),
Roots.end());
// Remove the modules from the PCH chain.
for (auto I = first; I != last; ++I) {
if (!(*I)->isModule()) {
PCHChain.erase(std::find(PCHChain.begin(), PCHChain.end(), *I),
PCHChain.end());
break;
}
}
// Delete the modules and erase them from the various structures.
for (ModuleIterator victim = first; victim != last; ++victim) {
Modules.erase((*victim)->File);
if (modMap) {
StringRef ModuleName = (*victim)->ModuleName;
if (Module *mod = modMap->findModule(ModuleName)) {
mod->setASTFile(nullptr);
}
}
// 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);
delete *victim;
}
// Remove the modules from the chain.
Chain.erase(first, last);
}
void
ModuleManager::addInMemoryBuffer(StringRef FileName,
std::unique_ptr<llvm::MemoryBuffer> Buffer) {
const FileEntry *Entry =
FileMgr.getVirtualFile(FileName, Buffer->getBufferSize(), 0);
InMemoryBuffers[Entry] = std::move(Buffer);
}
ModuleManager::VisitState *ModuleManager::allocateVisitState() {
// Fast path: if we have a cached state, use it.
if (FirstVisitState) {
VisitState *Result = FirstVisitState;
FirstVisitState = FirstVisitState->NextState;
Result->NextState = nullptr;
return Result;
}
// Allocate and return a new state.
return new VisitState(size());
}
void ModuleManager::returnVisitState(VisitState *State) {
assert(State->NextState == nullptr && "Visited state is in list?");
State->NextState = FirstVisitState;
FirstVisitState = State;
}
void ModuleManager::setGlobalIndex(GlobalModuleIndex *Index) {
GlobalIndex = Index;
if (!GlobalIndex) {
ModulesInCommonWithGlobalIndex.clear();
return;
}
// Notify the global module index about all of the modules we've already
// loaded.
for (unsigned I = 0, N = Chain.size(); I != N; ++I) {
if (!GlobalIndex->loadedModuleFile(Chain[I])) {
ModulesInCommonWithGlobalIndex.push_back(Chain[I]);
}
}
}
void ModuleManager::moduleFileAccepted(ModuleFile *MF) {
if (!GlobalIndex || GlobalIndex->loadedModuleFile(MF))
return;
ModulesInCommonWithGlobalIndex.push_back(MF);
}
ModuleManager::ModuleManager(FileManager &FileMgr,
const PCHContainerReader &PCHContainerRdr)
: FileMgr(FileMgr), PCHContainerRdr(PCHContainerRdr), GlobalIndex(),
FirstVisitState(nullptr) {}
ModuleManager::~ModuleManager() {
for (unsigned i = 0, e = Chain.size(); i != e; ++i)
delete Chain[e - i - 1];
delete FirstVisitState;
}
void ModuleManager::visit(llvm::function_ref<bool(ModuleFile &M)> Visitor,
llvm::SmallPtrSetImpl<ModuleFile *> *ModuleFilesHit) {
// If the visitation order vector is the wrong size, recompute the order.
if (VisitOrder.size() != Chain.size()) {
unsigned N = size();
VisitOrder.clear();
VisitOrder.reserve(N);
// Record the number of incoming edges for each module. When we
// encounter a module with no incoming edges, push it into the queue
// to seed the queue.
SmallVector<ModuleFile *, 4> Queue;
Queue.reserve(N);
llvm::SmallVector<unsigned, 4> UnusedIncomingEdges;
UnusedIncomingEdges.resize(size());
for (ModuleFile *M : llvm::reverse(*this)) {
unsigned Size = M->ImportedBy.size();
UnusedIncomingEdges[M->Index] = Size;
if (!Size)
Queue.push_back(M);
}
// Traverse the graph, making sure to visit a module before visiting any
// of its dependencies.
while (!Queue.empty()) {
ModuleFile *CurrentModule = Queue.pop_back_val();
VisitOrder.push_back(CurrentModule);
// For any module that this module depends on, push it on the
// stack (if it hasn't already been marked as visited).
for (auto M = CurrentModule->Imports.rbegin(),
MEnd = CurrentModule->Imports.rend();
M != MEnd; ++M) {
// Remove our current module as an impediment to visiting the
// module we depend on. If we were the last unvisited module
// that depends on this particular module, push it into the
// queue to be visited.
unsigned &NumUnusedEdges = UnusedIncomingEdges[(*M)->Index];
if (NumUnusedEdges && (--NumUnusedEdges == 0))
Queue.push_back(*M);
}
}
assert(VisitOrder.size() == N && "Visitation order is wrong?");
delete FirstVisitState;
FirstVisitState = nullptr;
}
VisitState *State = allocateVisitState();
unsigned VisitNumber = State->NextVisitNumber++;
// If the caller has provided us with a hit-set that came from the global
// module index, mark every module file in common with the global module
// index that is *not* in that set as 'visited'.
if (ModuleFilesHit && !ModulesInCommonWithGlobalIndex.empty()) {
for (unsigned I = 0, N = ModulesInCommonWithGlobalIndex.size(); I != N; ++I)
{
ModuleFile *M = ModulesInCommonWithGlobalIndex[I];
if (!ModuleFilesHit->count(M))
State->VisitNumber[M->Index] = VisitNumber;
}
}
for (unsigned I = 0, N = VisitOrder.size(); I != N; ++I) {
ModuleFile *CurrentModule = VisitOrder[I];
// Should we skip this module file?
if (State->VisitNumber[CurrentModule->Index] == VisitNumber)
continue;
// Visit the module.
assert(State->VisitNumber[CurrentModule->Index] == VisitNumber - 1);
State->VisitNumber[CurrentModule->Index] = VisitNumber;
if (!Visitor(*CurrentModule))
continue;
// The visitor has requested that cut off visitation of any
// module that the current module depends on. To indicate this
// behavior, we mark all of the reachable modules as having been visited.
ModuleFile *NextModule = CurrentModule;
do {
// For any module that this module depends on, push it on the
// stack (if it hasn't already been marked as visited).
for (llvm::SetVector<ModuleFile *>::iterator
M = NextModule->Imports.begin(),
MEnd = NextModule->Imports.end();
M != MEnd; ++M) {
if (State->VisitNumber[(*M)->Index] != VisitNumber) {
State->Stack.push_back(*M);
State->VisitNumber[(*M)->Index] = VisitNumber;
}
}
if (State->Stack.empty())
break;
// Pop the next module off the stack.
NextModule = State->Stack.pop_back_val();
} while (true);
}
returnVisitState(State);
}
bool ModuleManager::lookupModuleFile(StringRef FileName,
off_t ExpectedSize,
time_t ExpectedModTime,
const FileEntry *&File) {
if (FileName == "-") {
File = nullptr;
return false;
}
// Open the file immediately to ensure there is no race between stat'ing and
// opening the file.
File = FileMgr.getFile(FileName, /*openFile=*/true, /*cacheFailure=*/false);
if (!File)
return false;
if ((ExpectedSize && ExpectedSize != File->getSize()) ||
(ExpectedModTime && ExpectedModTime != File->getModificationTime()))
// Do not destroy File, as it may be referenced. If we need to rebuild it,
// it will be destroyed by removeModules.
return true;
return false;
}
#ifndef NDEBUG
namespace llvm {
template<>
struct GraphTraits<ModuleManager> {
typedef ModuleFile *NodeRef;
typedef llvm::SetVector<ModuleFile *>::const_iterator ChildIteratorType;
typedef ModuleManager::ModuleConstIterator nodes_iterator;
static ChildIteratorType child_begin(NodeRef Node) {
return Node->Imports.begin();
}
static ChildIteratorType child_end(NodeRef Node) {
return Node->Imports.end();
}
static nodes_iterator nodes_begin(const ModuleManager &Manager) {
return Manager.begin();
}
static nodes_iterator nodes_end(const ModuleManager &Manager) {
return Manager.end();
}
};
template<>
struct DOTGraphTraits<ModuleManager> : public DefaultDOTGraphTraits {
explicit DOTGraphTraits(bool IsSimple = false)
: DefaultDOTGraphTraits(IsSimple) { }
static bool renderGraphFromBottomUp() {
return true;
}
std::string getNodeLabel(ModuleFile *M, const ModuleManager&) {
return M->ModuleName;
}
};
}
void ModuleManager::viewGraph() {
llvm::ViewGraph(*this, "Modules");
}
#endif
