Merge "Update prebuilt Clang to r353983." into p9.0HEADp9.0-backupp9.0

1 files changed, 687 insertions, 0 deletions

diff --git a/clang-r353983/include/clang/Lex/ModuleMap.h b/clang-r353983/include/clang/Lex/ModuleMap.h
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+//===- ModuleMap.h - Describe the layout of modules -------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the ModuleMap interface, which describes the layout of a
+// module as it relates to headers.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_LEX_MODULEMAP_H
+#define LLVM_CLANG_LEX_MODULEMAP_H
+
+#include "clang/Basic/LangOptions.h"
+#include "clang/Basic/Module.h"
+#include "clang/Basic/SourceLocation.h"
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/PointerIntPair.h"
+#include "llvm/ADT/StringSet.h"
+#include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/StringMap.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/ADT/TinyPtrVector.h"
+#include "llvm/ADT/Twine.h"
+#include <ctime>
+#include <memory>
+#include <string>
+#include <utility>
+
+namespace clang {
+
+class DiagnosticsEngine;
+class DirectoryEntry;
+class FileEntry;
+class FileManager;
+class HeaderSearch;
+class SourceManager;
+
+/// A mechanism to observe the actions of the module map parser as it
+/// reads module map files.
+class ModuleMapCallbacks {
+  virtual void anchor();
+
+public:
+  virtual ~ModuleMapCallbacks() = default;
+
+  /// Called when a module map file has been read.
+  ///
+  /// \param FileStart A SourceLocation referring to the start of the file's
+  /// contents.
+  /// \param File The file itself.
+  /// \param IsSystem Whether this is a module map from a system include path.
+  virtual void moduleMapFileRead(SourceLocation FileStart,
+                                 const FileEntry &File, bool IsSystem) {}
+
+  /// Called when a header is added during module map parsing.
+  ///
+  /// \param Filename The header file itself.
+  virtual void moduleMapAddHeader(StringRef Filename) {}
+
+  /// Called when an umbrella header is added during module map parsing.
+  ///
+  /// \param FileMgr FileManager instance
+  /// \param Header The umbrella header to collect.
+  virtual void moduleMapAddUmbrellaHeader(FileManager *FileMgr,
+                                          const FileEntry *Header) {}
+};
+
+class ModuleMap {
+  SourceManager &SourceMgr;
+  DiagnosticsEngine &Diags;
+  const LangOptions &LangOpts;
+  const TargetInfo *Target;
+  HeaderSearch &HeaderInfo;
+
+  llvm::SmallVector<std::unique_ptr<ModuleMapCallbacks>, 1> Callbacks;
+
+  /// The directory used for Clang-supplied, builtin include headers,
+  /// such as "stdint.h".
+  const DirectoryEntry *BuiltinIncludeDir = nullptr;
+
+  /// Language options used to parse the module map itself.
+  ///
+  /// These are always simple C language options.
+  LangOptions MMapLangOpts;
+
+  /// The module that the main source file is associated with (the module
+  /// named LangOpts::CurrentModule, if we've loaded it).
+  Module *SourceModule = nullptr;
+
+  /// Submodules of the current module that have not yet been attached to it.
+  /// (Ownership is transferred if/when we create an enclosing module.)
+  llvm::SmallVector<std::unique_ptr<Module>, 8> PendingSubmodules;
+
+  /// The top-level modules that are known.
+  llvm::StringMap<Module *> Modules;
+
+  /// Shadow modules created while building this module map.
+  llvm::SmallVector<Module*, 2> ShadowModules;
+
+  /// The number of modules we have created in total.
+  unsigned NumCreatedModules = 0;
+
+  /// In case a module has a export_as entry, it might have a pending link
+  /// name to be determined if that module is imported.
+  llvm::StringMap<llvm::StringSet<>> PendingLinkAsModule;
+
+public:
+  /// Use PendingLinkAsModule information to mark top level link names that
+  /// are going to be replaced by export_as aliases.
+  void resolveLinkAsDependencies(Module *Mod);
+
+  /// Make module to use export_as as the link dependency name if enough
+  /// information is available or add it to a pending list otherwise.
+  void addLinkAsDependency(Module *Mod);
+
+  /// Flags describing the role of a module header.
+  enum ModuleHeaderRole {
+    /// This header is normally included in the module.
+    NormalHeader  = 0x0,
+
+    /// This header is included but private.
+    PrivateHeader = 0x1,
+
+    /// This header is part of the module (for layering purposes) but
+    /// should be textually included.
+    TextualHeader = 0x2,
+
+    // Caution: Adding an enumerator needs other changes.
+    // Adjust the number of bits for KnownHeader::Storage.
+    // Adjust the bitfield HeaderFileInfo::HeaderRole size.
+    // Adjust the HeaderFileInfoTrait::ReadData streaming.
+    // Adjust the HeaderFileInfoTrait::EmitData streaming.
+    // Adjust ModuleMap::addHeader.
+  };
+
+  /// Convert a header kind to a role. Requires Kind to not be HK_Excluded.
+  static ModuleHeaderRole headerKindToRole(Module::HeaderKind Kind);
+
+  /// Convert a header role to a kind.
+  static Module::HeaderKind headerRoleToKind(ModuleHeaderRole Role);
+
+  /// A header that is known to reside within a given module,
+  /// whether it was included or excluded.
+  class KnownHeader {
+    llvm::PointerIntPair<Module *, 2, ModuleHeaderRole> Storage;
+
+  public:
+    KnownHeader() : Storage(nullptr, NormalHeader) {}
+    KnownHeader(Module *M, ModuleHeaderRole Role) : Storage(M, Role) {}
+
+    friend bool operator==(const KnownHeader &A, const KnownHeader &B) {
+      return A.Storage == B.Storage;
+    }
+    friend bool operator!=(const KnownHeader &A, const KnownHeader &B) {
+      return A.Storage != B.Storage;
+    }
+
+    /// Retrieve the module the header is stored in.
+    Module *getModule() const { return Storage.getPointer(); }
+
+    /// The role of this header within the module.
+    ModuleHeaderRole getRole() const { return Storage.getInt(); }
+
+    /// Whether this header is available in the module.
+    bool isAvailable() const {
+      return getModule()->isAvailable();
+    }
+
+    /// Whether this header is accessible from the specified module.
+    bool isAccessibleFrom(Module *M) const {
+      return !(getRole() & PrivateHeader) ||
+             (M && M->getTopLevelModule() == getModule()->getTopLevelModule());
+    }
+
+    // Whether this known header is valid (i.e., it has an
+    // associated module).
+    explicit operator bool() const {
+      return Storage.getPointer() != nullptr;
+    }
+  };
+
+  using AdditionalModMapsSet = llvm::SmallPtrSet<const FileEntry *, 1>;
+
+private:
+  friend class ModuleMapParser;
+
+  using HeadersMap =
+      llvm::DenseMap<const FileEntry *, SmallVector<KnownHeader, 1>>;
+
+  /// Mapping from each header to the module that owns the contents of
+  /// that header.
+  HeadersMap Headers;
+
+  /// Map from file sizes to modules with lazy header directives of that size.
+  mutable llvm::DenseMap<off_t, llvm::TinyPtrVector<Module*>> LazyHeadersBySize;
+
+  /// Map from mtimes to modules with lazy header directives with those mtimes.
+  mutable llvm::DenseMap<time_t, llvm::TinyPtrVector<Module*>>
+              LazyHeadersByModTime;
+
+  /// Mapping from directories with umbrella headers to the module
+  /// that is generated from the umbrella header.
+  ///
+  /// This mapping is used to map headers that haven't explicitly been named
+  /// in the module map over to the module that includes them via its umbrella
+  /// header.
+  llvm::DenseMap<const DirectoryEntry *, Module *> UmbrellaDirs;
+
+  /// A generation counter that is used to test whether modules of the
+  /// same name may shadow or are illegal redefinitions.
+  ///
+  /// Modules from earlier scopes may shadow modules from later ones.
+  /// Modules from the same scope may not have the same name.
+  unsigned CurrentModuleScopeID = 0;
+
+  llvm::DenseMap<Module *, unsigned> ModuleScopeIDs;
+
+  /// The set of attributes that can be attached to a module.
+  struct Attributes {
+    /// Whether this is a system module.
+    unsigned IsSystem : 1;
+
+    /// Whether this is an extern "C" module.
+    unsigned IsExternC : 1;
+
+    /// Whether this is an exhaustive set of configuration macros.
+    unsigned IsExhaustive : 1;
+
+    /// Whether files in this module can only include non-modular headers
+    /// and headers from used modules.
+    unsigned NoUndeclaredIncludes : 1;
+
+    Attributes()
+        : IsSystem(false), IsExternC(false), IsExhaustive(false),
+          NoUndeclaredIncludes(false) {}
+  };
+
+  /// A directory for which framework modules can be inferred.
+  struct InferredDirectory {
+    /// Whether to infer modules from this directory.
+    unsigned InferModules : 1;
+
+    /// The attributes to use for inferred modules.
+    Attributes Attrs;
+
+    /// If \c InferModules is non-zero, the module map file that allowed
+    /// inferred modules.  Otherwise, nullptr.
+    const FileEntry *ModuleMapFile;
+
+    /// The names of modules that cannot be inferred within this
+    /// directory.
+    SmallVector<std::string, 2> ExcludedModules;
+
+    InferredDirectory() : InferModules(false) {}
+  };
+
+  /// A mapping from directories to information about inferring
+  /// framework modules from within those directories.
+  llvm::DenseMap<const DirectoryEntry *, InferredDirectory> InferredDirectories;
+
+  /// A mapping from an inferred module to the module map that allowed the
+  /// inference.
+  llvm::DenseMap<const Module *, const FileEntry *> InferredModuleAllowedBy;
+
+  llvm::DenseMap<const Module *, AdditionalModMapsSet> AdditionalModMaps;
+
+  /// Describes whether we haved parsed a particular file as a module
+  /// map.
+  llvm::DenseMap<const FileEntry *, bool> ParsedModuleMap;
+
+  /// Resolve the given export declaration into an actual export
+  /// declaration.
+  ///
+  /// \param Mod The module in which we're resolving the export declaration.
+  ///
+  /// \param Unresolved The export declaration to resolve.
+  ///
+  /// \param Complain Whether this routine should complain about unresolvable
+  /// exports.
+  ///
+  /// \returns The resolved export declaration, which will have a NULL pointer
+  /// if the export could not be resolved.
+  Module::ExportDecl
+  resolveExport(Module *Mod, const Module::UnresolvedExportDecl &Unresolved,
+                bool Complain) const;
+
+  /// Resolve the given module id to an actual module.
+  ///
+  /// \param Id The module-id to resolve.
+  ///
+  /// \param Mod The module in which we're resolving the module-id.
+  ///
+  /// \param Complain Whether this routine should complain about unresolvable
+  /// module-ids.
+  ///
+  /// \returns The resolved module, or null if the module-id could not be
+  /// resolved.
+  Module *resolveModuleId(const ModuleId &Id, Module *Mod, bool Complain) const;
+
+  /// Add an unresolved header to a module.
+  ///
+  /// \param Mod The module in which we're adding the unresolved header
+  ///        directive.
+  /// \param Header The unresolved header directive.
+  /// \param NeedsFramework If Mod is not a framework but a missing header would
+  ///        be found in case Mod was, set it to true. False otherwise.
+  void addUnresolvedHeader(Module *Mod,
+                           Module::UnresolvedHeaderDirective Header,
+                           bool &NeedsFramework);
+
+  /// Look up the given header directive to find an actual header file.
+  ///
+  /// \param M The module in which we're resolving the header directive.
+  /// \param Header The header directive to resolve.
+  /// \param RelativePathName Filled in with the relative path name from the
+  ///        module to the resolved header.
+  /// \param NeedsFramework If M is not a framework but a missing header would
+  ///        be found in case M was, set it to true. False otherwise.
+  /// \return The resolved file, if any.
+  const FileEntry *findHeader(Module *M,
+                              const Module::UnresolvedHeaderDirective &Header,
+                              SmallVectorImpl<char> &RelativePathName,
+                              bool &NeedsFramework);
+
+  /// Resolve the given header directive.
+  ///
+  /// \param M The module in which we're resolving the header directive.
+  /// \param Header The header directive to resolve.
+  /// \param NeedsFramework If M is not a framework but a missing header would
+  ///        be found in case M was, set it to true. False otherwise.
+  void resolveHeader(Module *M, const Module::UnresolvedHeaderDirective &Header,
+                     bool &NeedsFramework);
+
+  /// Attempt to resolve the specified header directive as naming a builtin
+  /// header.
+  /// \return \c true if a corresponding builtin header was found.
+  bool resolveAsBuiltinHeader(Module *M,
+                              const Module::UnresolvedHeaderDirective &Header);
+
+  /// Looks up the modules that \p File corresponds to.
+  ///
+  /// If \p File represents a builtin header within Clang's builtin include
+  /// directory, this also loads all of the module maps to see if it will get
+  /// associated with a specific module (e.g. in /usr/include).
+  HeadersMap::iterator findKnownHeader(const FileEntry *File);
+
+  /// Searches for a module whose umbrella directory contains \p File.
+  ///
+  /// \param File The header to search for.
+  ///
+  /// \param IntermediateDirs On success, contains the set of directories
+  /// searched before finding \p File.
+  KnownHeader findHeaderInUmbrellaDirs(const FileEntry *File,
+                    SmallVectorImpl<const DirectoryEntry *> &IntermediateDirs);
+
+  /// Given that \p File is not in the Headers map, look it up within
+  /// umbrella directories and find or create a module for it.
+  KnownHeader findOrCreateModuleForHeaderInUmbrellaDir(const FileEntry *File);
+
+  /// A convenience method to determine if \p File is (possibly nested)
+  /// in an umbrella directory.
+  bool isHeaderInUmbrellaDirs(const FileEntry *File) {
+    SmallVector<const DirectoryEntry *, 2> IntermediateDirs;
+    return static_cast<bool>(findHeaderInUmbrellaDirs(File, IntermediateDirs));
+  }
+
+  Module *inferFrameworkModule(const DirectoryEntry *FrameworkDir,
+                               Attributes Attrs, Module *Parent);
+
+public:
+  /// Construct a new module map.
+  ///
+  /// \param SourceMgr The source manager used to find module files and headers.
+  /// This source manager should be shared with the header-search mechanism,
+  /// since they will refer to the same headers.
+  ///
+  /// \param Diags A diagnostic engine used for diagnostics.
+  ///
+  /// \param LangOpts Language options for this translation unit.
+  ///
+  /// \param Target The target for this translation unit.
+  ModuleMap(SourceManager &SourceMgr, DiagnosticsEngine &Diags,
+            const LangOptions &LangOpts, const TargetInfo *Target,
+            HeaderSearch &HeaderInfo);
+
+  /// Destroy the module map.
+  ~ModuleMap();
+
+  /// Set the target information.
+  void setTarget(const TargetInfo &Target);
+
+  /// Set the directory that contains Clang-supplied include
+  /// files, such as our stdarg.h or tgmath.h.
+  void setBuiltinIncludeDir(const DirectoryEntry *Dir) {
+    BuiltinIncludeDir = Dir;
+  }
+
+  /// Get the directory that contains Clang-supplied include files.
+  const DirectoryEntry *getBuiltinDir() const {
+    return BuiltinIncludeDir;
+  }
+
+  /// Is this a compiler builtin header?
+  static bool isBuiltinHeader(StringRef FileName);
+
+  /// Add a module map callback.
+  void addModuleMapCallbacks(std::unique_ptr<ModuleMapCallbacks> Callback) {
+    Callbacks.push_back(std::move(Callback));
+  }
+
+  /// Retrieve the module that owns the given header file, if any.
+  ///
+  /// \param File The header file that is likely to be included.
+  ///
+  /// \param AllowTextual If \c true and \p File is a textual header, return
+  /// its owning module. Otherwise, no KnownHeader will be returned if the
+  /// file is only known as a textual header.
+  ///
+  /// \returns The module KnownHeader, which provides the module that owns the
+  /// given header file.  The KnownHeader is default constructed to indicate
+  /// that no module owns this header file.
+  KnownHeader findModuleForHeader(const FileEntry *File,
+                                  bool AllowTextual = false);
+
+  /// Retrieve all the modules that contain the given header file. This
+  /// may not include umbrella modules, nor information from external sources,
+  /// if they have not yet been inferred / loaded.
+  ///
+  /// Typically, \ref findModuleForHeader should be used instead, as it picks
+  /// the preferred module for the header.
+  ArrayRef<KnownHeader> findAllModulesForHeader(const FileEntry *File) const;
+
+  /// Resolve all lazy header directives for the specified file.
+  ///
+  /// This ensures that the HeaderFileInfo on HeaderSearch is up to date. This
+  /// is effectively internal, but is exposed so HeaderSearch can call it.
+  void resolveHeaderDirectives(const FileEntry *File) const;
+
+  /// Resolve all lazy header directives for the specified module.
+  void resolveHeaderDirectives(Module *Mod) const;
+
+  /// Reports errors if a module must not include a specific file.
+  ///
+  /// \param RequestingModule The module including a file.
+  ///
+  /// \param RequestingModuleIsModuleInterface \c true if the inclusion is in
+  ///        the interface of RequestingModule, \c false if it's in the
+  ///        implementation of RequestingModule. Value is ignored and
+  ///        meaningless if RequestingModule is nullptr.
+  ///
+  /// \param FilenameLoc The location of the inclusion's filename.
+  ///
+  /// \param Filename The included filename as written.
+  ///
+  /// \param File The included file.
+  void diagnoseHeaderInclusion(Module *RequestingModule,
+                               bool RequestingModuleIsModuleInterface,
+                               SourceLocation FilenameLoc, StringRef Filename,
+                               const FileEntry *File);
+
+  /// Determine whether the given header is part of a module
+  /// marked 'unavailable'.
+  bool isHeaderInUnavailableModule(const FileEntry *Header) const;
+
+  /// Determine whether the given header is unavailable as part
+  /// of the specified module.
+  bool isHeaderUnavailableInModule(const FileEntry *Header,
+                                   const Module *RequestingModule) const;
+
+  /// Retrieve a module with the given name.
+  ///
+  /// \param Name The name of the module to look up.
+  ///
+  /// \returns The named module, if known; otherwise, returns null.
+  Module *findModule(StringRef Name) const;
+
+  /// Retrieve a module with the given name using lexical name lookup,
+  /// starting at the given context.
+  ///
+  /// \param Name The name of the module to look up.
+  ///
+  /// \param Context The module context, from which we will perform lexical
+  /// name lookup.
+  ///
+  /// \returns The named module, if known; otherwise, returns null.
+  Module *lookupModuleUnqualified(StringRef Name, Module *Context) const;
+
+  /// Retrieve a module with the given name within the given context,
+  /// using direct (qualified) name lookup.
+  ///
+  /// \param Name The name of the module to look up.
+  ///
+  /// \param Context The module for which we will look for a submodule. If
+  /// null, we will look for a top-level module.
+  ///
+  /// \returns The named submodule, if known; otherwose, returns null.
+  Module *lookupModuleQualified(StringRef Name, Module *Context) const;
+
+  /// Find a new module or submodule, or create it if it does not already
+  /// exist.
+  ///
+  /// \param Name The name of the module to find or create.
+  ///
+  /// \param Parent The module that will act as the parent of this submodule,
+  /// or nullptr to indicate that this is a top-level module.
+  ///
+  /// \param IsFramework Whether this is a framework module.
+  ///
+  /// \param IsExplicit Whether this is an explicit submodule.
+  ///
+  /// \returns The found or newly-created module, along with a boolean value
+  /// that will be true if the module is newly-created.
+  std::pair<Module *, bool> findOrCreateModule(StringRef Name, Module *Parent,
+                                               bool IsFramework,
+                                               bool IsExplicit);
+
+  /// Create a 'global module' for a C++ Modules TS module interface unit.
+  ///
+  /// We model the global module as a submodule of the module interface unit.
+  /// Unfortunately, we can't create the module interface unit's Module until
+  /// later, because we don't know what it will be called.
+  Module *createGlobalModuleForInterfaceUnit(SourceLocation Loc);
+
+  /// Create a new module for a C++ Modules TS module interface unit.
+  /// The module must not already exist, and will be configured for the current
+  /// compilation.
+  ///
+  /// Note that this also sets the current module to the newly-created module.
+  ///
+  /// \returns The newly-created module.
+  Module *createModuleForInterfaceUnit(SourceLocation Loc, StringRef Name,
+                                       Module *GlobalModule);
+
+  /// Create a header module from the specified list of headers.
+  Module *createHeaderModule(StringRef Name, ArrayRef<Module::Header> Headers);
+
+  /// Infer the contents of a framework module map from the given
+  /// framework directory.
+  Module *inferFrameworkModule(const DirectoryEntry *FrameworkDir,
+                               bool IsSystem, Module *Parent);
+
+  /// Create a new top-level module that is shadowed by
+  /// \p ShadowingModule.
+  Module *createShadowedModule(StringRef Name, bool IsFramework,
+                               Module *ShadowingModule);
+
+  /// Creates a new declaration scope for module names, allowing
+  /// previously defined modules to shadow definitions from the new scope.
+  ///
+  /// \note Module names from earlier scopes will shadow names from the new
+  /// scope, which is the opposite of how shadowing works for variables.
+  void finishModuleDeclarationScope() { CurrentModuleScopeID += 1; }
+
+  bool mayShadowNewModule(Module *ExistingModule) {
+    assert(!ExistingModule->Parent && "expected top-level module");
+    assert(ModuleScopeIDs.count(ExistingModule) && "unknown module");
+    return ModuleScopeIDs[ExistingModule] < CurrentModuleScopeID;
+  }
+
+  /// Retrieve the module map file containing the definition of the given
+  /// module.
+  ///
+  /// \param Module The module whose module map file will be returned, if known.
+  ///
+  /// \returns The file entry for the module map file containing the given
+  /// module, or nullptr if the module definition was inferred.
+  const FileEntry *getContainingModuleMapFile(const Module *Module) const;
+
+  /// Get the module map file that (along with the module name) uniquely
+  /// identifies this module.
+  ///
+  /// The particular module that \c Name refers to may depend on how the module
+  /// was found in header search. However, the combination of \c Name and
+  /// this module map will be globally unique for top-level modules. In the case
+  /// of inferred modules, returns the module map that allowed the inference
+  /// (e.g. contained 'module *'). Otherwise, returns
+  /// getContainingModuleMapFile().
+  const FileEntry *getModuleMapFileForUniquing(const Module *M) const;
+
+  void setInferredModuleAllowedBy(Module *M, const FileEntry *ModMap);
+
+  /// Get any module map files other than getModuleMapFileForUniquing(M)
+  /// that define submodules of a top-level module \p M. This is cheaper than
+  /// getting the module map file for each submodule individually, since the
+  /// expected number of results is very small.
+  AdditionalModMapsSet *getAdditionalModuleMapFiles(const Module *M) {
+    auto I = AdditionalModMaps.find(M);
+    if (I == AdditionalModMaps.end())
+      return nullptr;
+    return &I->second;
+  }
+
+  void addAdditionalModuleMapFile(const Module *M, const FileEntry *ModuleMap) {
+    AdditionalModMaps[M].insert(ModuleMap);
+  }
+
+  /// Resolve all of the unresolved exports in the given module.
+  ///
+  /// \param Mod The module whose exports should be resolved.
+  ///
+  /// \param Complain Whether to emit diagnostics for failures.
+  ///
+  /// \returns true if any errors were encountered while resolving exports,
+  /// false otherwise.
+  bool resolveExports(Module *Mod, bool Complain);
+
+  /// Resolve all of the unresolved uses in the given module.
+  ///
+  /// \param Mod The module whose uses should be resolved.
+  ///
+  /// \param Complain Whether to emit diagnostics for failures.
+  ///
+  /// \returns true if any errors were encountered while resolving uses,
+  /// false otherwise.
+  bool resolveUses(Module *Mod, bool Complain);
+
+  /// Resolve all of the unresolved conflicts in the given module.
+  ///
+  /// \param Mod The module whose conflicts should be resolved.
+  ///
+  /// \param Complain Whether to emit diagnostics for failures.
+  ///
+  /// \returns true if any errors were encountered while resolving conflicts,
+  /// false otherwise.
+  bool resolveConflicts(Module *Mod, bool Complain);
+
+  /// Sets the umbrella header of the given module to the given
+  /// header.
+  void setUmbrellaHeader(Module *Mod, const FileEntry *UmbrellaHeader,
+                         Twine NameAsWritten);
+
+  /// Sets the umbrella directory of the given module to the given
+  /// directory.
+  void setUmbrellaDir(Module *Mod, const DirectoryEntry *UmbrellaDir,
+                      Twine NameAsWritten);
+
+  /// Adds this header to the given module.
+  /// \param Role The role of the header wrt the module.
+  void addHeader(Module *Mod, Module::Header Header,
+                 ModuleHeaderRole Role, bool Imported = false);
+
+  /// Marks this header as being excluded from the given module.
+  void excludeHeader(Module *Mod, Module::Header Header);
+
+  /// Parse the given module map file, and record any modules we
+  /// encounter.
+  ///
+  /// \param File The file to be parsed.
+  ///
+  /// \param IsSystem Whether this module map file is in a system header
+  /// directory, and therefore should be considered a system module.
+  ///
+  /// \param HomeDir The directory in which relative paths within this module
+  ///        map file will be resolved.
+  ///
+  /// \param ID The FileID of the file to process, if we've already entered it.
+  ///
+  /// \param Offset [inout] On input the offset at which to start parsing. On
+  ///        output, the offset at which the module map terminated.
+  ///
+  /// \param ExternModuleLoc The location of the "extern module" declaration
+  ///        that caused us to load this module map file, if any.
+  ///
+  /// \returns true if an error occurred, false otherwise.
+  bool parseModuleMapFile(const FileEntry *File, bool IsSystem,
+                          const DirectoryEntry *HomeDir,
+                          FileID ID = FileID(), unsigned *Offset = nullptr,
+                          SourceLocation ExternModuleLoc = SourceLocation());
+
+  /// Dump the contents of the module map, for debugging purposes.
+  void dump();
+
+  using module_iterator = llvm::StringMap<Module *>::const_iterator;
+
+  module_iterator module_begin() const { return Modules.begin(); }
+  module_iterator module_end()   const { return Modules.end(); }
+};
+
+} // namespace clang
+
+#endif // LLVM_CLANG_LEX_MODULEMAP_H