ModuleLoader.h revision 6bcf27bb9a4b5c3f79cb44c0e4654a6d7619ad89 
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
22namespace clang {
23
24class GlobalModuleIndex;
25class IdentifierInfo;
26class Module;
27
28/// \brief A sequence of identifier/location pairs used to describe a particular
29/// module or submodule, e.g., std.vector.
30typedef ArrayRef<std::pair<IdentifierInfo *, SourceLocation> > ModuleIdPath;
31
32/// \brief Describes the result of attempting to load a module.
33class ModuleLoadResult {
34  llvm::PointerIntPair<Module *, 1, bool> Storage;
35
36public:
37  ModuleLoadResult() : Storage() { }
38
39  ModuleLoadResult(Module *module, bool missingExpected)
40    : Storage(module, missingExpected) { }
41
42  operator Module *() const { return Storage.getPointer(); }
43
44  /// \brief Determines whether the module, which failed to load, was
45  /// actually a submodule that we expected to see (based on implying the
46  /// submodule from header structure), but didn't materialize in the actual
47  /// module.
48  bool isMissingExpected() const { return Storage.getInt(); }
49};
50
51/// \brief Abstract interface for a module loader.
52///
53/// This abstract interface describes a module loader, which is responsible
54/// for resolving a module name (e.g., "std") to an actual module file, and
55/// then loading that module.
56class ModuleLoader {
57  // Building a module if true.
58  bool BuildingModule;
59public:
60  explicit ModuleLoader(bool BuildingModule = false) :
61    BuildingModule(BuildingModule),
62    HadFatalFailure(false) {}
63
64  virtual ~ModuleLoader();
65
66  /// \brief Returns true if this instance is building a module.
67  bool buildingModule() const {
68    return BuildingModule;
69  }
70  /// \brief Flag indicating whether this instance is building a module.
71  void setBuildingModule(bool BuildingModuleFlag) {
72    BuildingModule = BuildingModuleFlag;
73  }
74
75  /// \brief Attempt to load the given module.
76  ///
77  /// This routine attempts to load the module described by the given
78  /// parameters.
79  ///
80  /// \param ImportLoc The location of the 'import' keyword.
81  ///
82  /// \param Path The identifiers (and their locations) of the module
83  /// "path", e.g., "std.vector" would be split into "std" and "vector".
84  ///
85  /// \param Visibility The visibility provided for the names in the loaded
86  /// module.
87  ///
88  /// \param IsInclusionDirective Indicates that this module is being loaded
89  /// implicitly, due to the presence of an inclusion directive. Otherwise,
90  /// it is being loaded due to an import declaration.
91  ///
92  /// \returns If successful, returns the loaded module. Otherwise, returns
93  /// NULL to indicate that the module could not be loaded.
94  virtual ModuleLoadResult loadModule(SourceLocation ImportLoc,
95                                      ModuleIdPath Path,
96                                      Module::NameVisibilityKind Visibility,
97                                      bool IsInclusionDirective) = 0;
98
99  /// \brief Make the given module visible.
100  virtual void makeModuleVisible(Module *Mod,
101                                 Module::NameVisibilityKind Visibility,
102                                 SourceLocation ImportLoc,
103                                 bool Complain) = 0;
104
105  /// \brief Load, create, or return global module.
106  /// This function returns an existing global module index, if one
107  /// had already been loaded or created, or loads one if it
108  /// exists, or creates one if it doesn't exist.
109  /// Also, importantly, if the index doesn't cover all the modules
110  /// in the module map, it will be update to do so here, because
111  /// of its use in searching for needed module imports and
112  /// associated fixit messages.
113  /// \param TriggerLoc The location for what triggered the load.
114  /// \returns Returns null if load failed.
115  virtual GlobalModuleIndex *loadGlobalModuleIndex(
116                                                SourceLocation TriggerLoc) = 0;
117
118  /// Check global module index for missing imports.
119  /// \param Name The symbol name to look for.
120  /// \param TriggerLoc The location for what triggered the load.
121  /// \returns Returns true if any modules with that symbol found.
122  virtual bool lookupMissingImports(StringRef Name,
123                                    SourceLocation TriggerLoc) = 0;
124
125  bool HadFatalFailure;
126};
127
128}
129
130#endif
131