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//===- ModuleManager.cpp - Module Manager -----------------------*- C++ -*-===//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
// This file defines the ModuleManager class, which manages a set of loaded
// modules for the ASTReader.
#include "clang/Basic/LLVM.h"
#include "clang/Basic/Module.h"
#include "clang/Basic/SourceLocation.h"
#include "clang/Serialization/ModuleFile.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/IntrusiveRefCntPtr.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/iterator.h"
#include "llvm/ADT/iterator_range.h"
#include <cstdint>
#include <ctime>
#include <memory>
#include <string>
#include <utility>
namespace clang {
class FileEntry;
class FileManager;
class GlobalModuleIndex;
class HeaderSearch;
class InMemoryModuleCache;
class ModuleMap;
class PCHContainerReader;
namespace serialization {
/// Manages the set of modules loaded by an AST reader.
class ModuleManager {
/// The chain of AST files, in the order in which we started to load
/// them (this order isn't really useful for anything).
SmallVector<std::unique_ptr<ModuleFile>, 2> Chain;
/// The chain of non-module PCH files. The first entry is the one named
/// by the user, the last one is the one that doesn't depend on anything
/// further.
SmallVector<ModuleFile *, 2> PCHChain;
// The roots of the dependency DAG of AST files. This is used
// to implement short-circuiting logic when running DFS over the dependencies.
SmallVector<ModuleFile *, 2> Roots;
/// All loaded modules, indexed by name.
llvm::DenseMap<const FileEntry *, ModuleFile *> Modules;
/// FileManager that handles translating between filenames and
/// FileEntry *.
FileManager &FileMgr;
/// Cache of PCM files.
IntrusiveRefCntPtr<InMemoryModuleCache> ModuleCache;
/// Knows how to unwrap module containers.
const PCHContainerReader &PCHContainerRdr;
/// Preprocessor's HeaderSearchInfo containing the module map.
const HeaderSearch &HeaderSearchInfo;
/// A lookup of in-memory (virtual file) buffers
llvm::DenseMap<const FileEntry *, std::unique_ptr<llvm::MemoryBuffer>>
/// The visitation order.
SmallVector<ModuleFile *, 4> VisitOrder;
/// The list of module files that both we and the global module index
/// know about.
/// Either the global index or the module manager may have modules that the
/// other does not know about, because the global index can be out-of-date
/// (in which case the module manager could have modules it does not) and
/// this particular translation unit might not have loaded all of the modules
/// known to the global index.
SmallVector<ModuleFile *, 4> ModulesInCommonWithGlobalIndex;
/// The global module index, if one is attached.
/// The global module index will actually be owned by the ASTReader; this is
/// just an non-owning pointer.
GlobalModuleIndex *GlobalIndex = nullptr;
/// State used by the "visit" operation to avoid malloc traffic in
/// calls to visit().
struct VisitState {
explicit VisitState(unsigned N) : VisitNumber(N, 0) {
~VisitState() {
delete NextState;
/// The stack used when marking the imports of a particular module
/// as not-to-be-visited.
SmallVector<ModuleFile *, 4> Stack;
/// The visit number of each module file, which indicates when
/// this module file was last visited.
SmallVector<unsigned, 4> VisitNumber;
/// The next visit number to use to mark visited module files.
unsigned NextVisitNumber = 1;
/// The next visit state.
VisitState *NextState = nullptr;
/// The first visit() state in the chain.
VisitState *FirstVisitState = nullptr;
VisitState *allocateVisitState();
void returnVisitState(VisitState *State);
using ModuleIterator = llvm::pointee_iterator<
using ModuleConstIterator = llvm::pointee_iterator<
using ModuleReverseIterator = llvm::pointee_iterator<
using ModuleOffset = std::pair<uint32_t, StringRef>;
explicit ModuleManager(FileManager &FileMgr, InMemoryModuleCache &ModuleCache,
const PCHContainerReader &PCHContainerRdr,
const HeaderSearch &HeaderSearchInfo);
/// Forward iterator to traverse all loaded modules.
ModuleIterator begin() { return Chain.begin(); }
/// Forward iterator end-point to traverse all loaded modules
ModuleIterator end() { return Chain.end(); }
/// Const forward iterator to traverse all loaded modules.
ModuleConstIterator begin() const { return Chain.begin(); }
/// Const forward iterator end-point to traverse all loaded modules
ModuleConstIterator end() const { return Chain.end(); }
/// Reverse iterator to traverse all loaded modules.
ModuleReverseIterator rbegin() { return Chain.rbegin(); }
/// Reverse iterator end-point to traverse all loaded modules.
ModuleReverseIterator rend() { return Chain.rend(); }
/// A range covering the PCH and preamble module files loaded.
llvm::iterator_range<SmallVectorImpl<ModuleFile *>::const_iterator>
pch_modules() const {
return llvm::make_range(PCHChain.begin(), PCHChain.end());
/// Returns the primary module associated with the manager, that is,
/// the first module loaded
ModuleFile &getPrimaryModule() { return *Chain[0]; }
/// Returns the primary module associated with the manager, that is,
/// the first module loaded.
ModuleFile &getPrimaryModule() const { return *Chain[0]; }
/// Returns the module associated with the given index
ModuleFile &operator[](unsigned Index) const { return *Chain[Index]; }
/// Returns the module associated with the given file name.
ModuleFile *lookupByFileName(StringRef FileName) const;
/// Returns the module associated with the given module name.
ModuleFile *lookupByModuleName(StringRef ModName) const;
/// Returns the module associated with the given module file.
ModuleFile *lookup(const FileEntry *File) const;
/// Returns the in-memory (virtual file) buffer with the given name
std::unique_ptr<llvm::MemoryBuffer> lookupBuffer(StringRef Name);
/// Number of modules loaded
unsigned size() const { return Chain.size(); }
/// The result of attempting to add a new module.
enum AddModuleResult {
/// The module file had already been loaded.
/// The module file was just loaded in response to this call.
/// The module file is missing.
/// The module file is out-of-date.
using ASTFileSignatureReader = ASTFileSignature (*)(StringRef);
/// Attempts to create a new module and add it to the list of known
/// modules.
/// \param FileName The file name of the module to be loaded.
/// \param Type The kind of module being loaded.
/// \param ImportLoc The location at which the module is imported.
/// \param ImportedBy The module that is importing this module, or NULL if
/// this module is imported directly by the user.
/// \param Generation The generation in which this module was loaded.
/// \param ExpectedSize The expected size of the module file, used for
/// validation. This will be zero if unknown.
/// \param ExpectedModTime The expected modification time of the module
/// file, used for validation. This will be zero if unknown.
/// \param ExpectedSignature The expected signature of the module file, used
/// for validation. This will be zero if unknown.
/// \param ReadSignature Reads the signature from an AST file without actually
/// loading it.
/// \param Module A pointer to the module file if the module was successfully
/// loaded.
/// \param ErrorStr Will be set to a non-empty string if any errors occurred
/// while trying to load the module.
/// \return A pointer to the module that corresponds to this file name,
/// and a value indicating whether the module was loaded.
AddModuleResult 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);
/// Remove the modules starting from First (to the end).
void removeModules(ModuleIterator First, ModuleMap *modMap);
/// Add an in-memory buffer the list of known buffers
void addInMemoryBuffer(StringRef FileName,
std::unique_ptr<llvm::MemoryBuffer> Buffer);
/// Set the global module index.
void setGlobalIndex(GlobalModuleIndex *Index);
/// Notification from the AST reader that the given module file
/// has been "accepted", and will not (can not) be unloaded.
void moduleFileAccepted(ModuleFile *MF);
/// Visit each of the modules.
/// This routine visits each of the modules, starting with the
/// "root" modules that no other loaded modules depend on, and
/// proceeding to the leaf modules, visiting each module only once
/// during the traversal.
/// This traversal is intended to support various "lookup"
/// operations that can find data in any of the loaded modules.
/// \param Visitor A visitor function that will be invoked with each
/// module. The return value must be convertible to bool; when false, the
/// visitation continues to modules that the current module depends on. When
/// true, the visitation skips any modules that the current module depends on.
/// \param ModuleFilesHit If non-NULL, contains the set of module files
/// that we know we need to visit because the global module index told us to.
/// Any module that is known to both the global module index and the module
/// manager that is *not* in this set can be skipped.
void visit(llvm::function_ref<bool(ModuleFile &M)> Visitor,
llvm::SmallPtrSetImpl<ModuleFile *> *ModuleFilesHit = nullptr);
/// Attempt to resolve the given module file name to a file entry.
/// \param FileName The name of the module file.
/// \param ExpectedSize The size that the module file is expected to have.
/// If the actual size differs, the resolver should return \c true.
/// \param ExpectedModTime The modification time that the module file is
/// expected to have. If the actual modification time differs, the resolver
/// should return \c true.
/// \param File Will be set to the file if there is one, or null
/// otherwise.
/// \returns True if a file exists but does not meet the size/
/// modification time criteria, false if the file is either available and
/// suitable, or is missing.
bool lookupModuleFile(StringRef FileName, off_t ExpectedSize,
time_t ExpectedModTime, Optional<FileEntryRef> &File);
/// View the graphviz representation of the module graph.
void viewGraph();
InMemoryModuleCache &getModuleCache() const { return *ModuleCache; }
} // namespace serialization
} // namespace clang