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      1 //===--- ModuleLoader.h - Module Loader Interface ---------------*- C++ -*-===//
      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 //  This file defines the ModuleLoader interface, which is responsible for
     11 //  loading named modules.
     12 //
     13 //===----------------------------------------------------------------------===//
     14 #ifndef LLVM_CLANG_LEX_MODULE_LOADER_H
     15 #define LLVM_CLANG_LEX_MODULE_LOADER_H
     16 
     17 #include "clang/Basic/Module.h"
     18 #include "clang/Basic/SourceLocation.h"
     19 #include "llvm/ADT/ArrayRef.h"
     20 #include "llvm/ADT/PointerIntPair.h"
     21 
     22 namespace clang {
     23 
     24 class IdentifierInfo;
     25 class Module;
     26 
     27 /// \brief A sequence of identifier/location pairs used to describe a particular
     28 /// module or submodule, e.g., std.vector.
     29 typedef ArrayRef<std::pair<IdentifierInfo *, SourceLocation> > ModuleIdPath;
     30 
     31 /// \brief Describes the result of attempting to load a module.
     32 class ModuleLoadResult {
     33   llvm::PointerIntPair<Module *, 1, bool> Storage;
     34 
     35 public:
     36   ModuleLoadResult() : Storage() { }
     37 
     38   ModuleLoadResult(Module *module, bool missingExpected)
     39     : Storage(module, missingExpected) { }
     40 
     41   operator Module *() const { return Storage.getPointer(); }
     42 
     43   /// \brief Determines whether the module, which failed to load, was
     44   /// actually a submodule that we expected to see (based on implying the
     45   /// submodule from header structure), but didn't materialize in the actual
     46   /// module.
     47   bool isMissingExpected() const { return Storage.getInt(); }
     48 };
     49 
     50 /// \brief Abstract interface for a module loader.
     51 ///
     52 /// This abstract interface describes a module loader, which is responsible
     53 /// for resolving a module name (e.g., "std") to an actual module file, and
     54 /// then loading that module.
     55 class ModuleLoader {
     56 public:
     57   ModuleLoader() : HadFatalFailure(false) {}
     58 
     59   virtual ~ModuleLoader();
     60 
     61   /// \brief Attempt to load the given module.
     62   ///
     63   /// This routine attempts to load the module described by the given
     64   /// parameters.
     65   ///
     66   /// \param ImportLoc The location of the 'import' keyword.
     67   ///
     68   /// \param Path The identifiers (and their locations) of the module
     69   /// "path", e.g., "std.vector" would be split into "std" and "vector".
     70   ///
     71   /// \param Visibility The visibility provided for the names in the loaded
     72   /// module.
     73   ///
     74   /// \param IsInclusionDirective Indicates that this module is being loaded
     75   /// implicitly, due to the presence of an inclusion directive. Otherwise,
     76   /// it is being loaded due to an import declaration.
     77   ///
     78   /// \returns If successful, returns the loaded module. Otherwise, returns
     79   /// NULL to indicate that the module could not be loaded.
     80   virtual ModuleLoadResult loadModule(SourceLocation ImportLoc,
     81                                       ModuleIdPath Path,
     82                                       Module::NameVisibilityKind Visibility,
     83                                       bool IsInclusionDirective) = 0;
     84 
     85   /// \brief Make the given module visible.
     86   virtual void makeModuleVisible(Module *Mod,
     87                                  Module::NameVisibilityKind Visibility,
     88                                  SourceLocation ImportLoc,
     89                                  bool Complain) = 0;
     90 
     91   bool HadFatalFailure;
     92 };
     93 
     94 }
     95 
     96 #endif
     97