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ModuleLoader.h
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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 
15 #ifndef LLVM_CLANG_LEX_MODULELOADER_H
16 #define LLVM_CLANG_LEX_MODULELOADER_H
17 
18 #include "clang/Basic/LLVM.h"
19 #include "clang/Basic/Module.h"
21 #include "llvm/ADT/ArrayRef.h"
22 #include "llvm/ADT/PointerIntPair.h"
23 #include "llvm/ADT/StringRef.h"
24 #include <utility>
25 
26 namespace clang {
27 
28 class GlobalModuleIndex;
29 class IdentifierInfo;
30 
31 /// \brief A sequence of identifier/location pairs used to describe a particular
32 /// module or submodule, e.g., std.vector.
34 
35 /// \brief Describes the result of attempting to load a module.
37 public:
39  // We either succeeded or failed to load the named module.
41 
42  // The module exists, but does not actually contain the named submodule.
43  // This should only happen if the named submodule was inferred from an
44  // umbrella directory, but not actually part of the umbrella header.
46 
47  // The module exists but cannot be imported due to a configuration mismatch.
49  };
50  llvm::PointerIntPair<Module *, 2, LoadResultKind> Storage;
51 
52  ModuleLoadResult() = default;
53  ModuleLoadResult(Module *M) : Storage(M, Normal) {}
54  ModuleLoadResult(LoadResultKind Kind) : Storage(nullptr, Kind) {}
55 
56  operator Module *() const { return Storage.getPointer(); }
57 
58  /// \brief Determines whether the module, which failed to load, was
59  /// actually a submodule that we expected to see (based on implying the
60  /// submodule from header structure), but didn't materialize in the actual
61  /// module.
62  bool isMissingExpected() const { return Storage.getInt() == MissingExpected; }
63 
64  /// \brief Determines whether the module failed to load due to a configuration
65  /// mismatch with an explicitly-named .pcm file from the command line.
66  bool isConfigMismatch() const { return Storage.getInt() == ConfigMismatch; }
67 };
68 
69 /// \brief Abstract interface for a module loader.
70 ///
71 /// This abstract interface describes a module loader, which is responsible
72 /// for resolving a module name (e.g., "std") to an actual module file, and
73 /// then loading that module.
74 class ModuleLoader {
75  // Building a module if true.
76  bool BuildingModule;
77 
78 public:
79  explicit ModuleLoader(bool BuildingModule = false)
80  : BuildingModule(BuildingModule) {}
81 
82  virtual ~ModuleLoader();
83 
84  /// \brief Returns true if this instance is building a module.
85  bool buildingModule() const {
86  return BuildingModule;
87  }
88 
89  /// \brief Flag indicating whether this instance is building a module.
90  void setBuildingModule(bool BuildingModuleFlag) {
91  BuildingModule = BuildingModuleFlag;
92  }
93 
94  /// \brief Attempt to load the given module.
95  ///
96  /// This routine attempts to load the module described by the given
97  /// parameters.
98  ///
99  /// \param ImportLoc The location of the 'import' keyword.
100  ///
101  /// \param Path The identifiers (and their locations) of the module
102  /// "path", e.g., "std.vector" would be split into "std" and "vector".
103  ///
104  /// \param Visibility The visibility provided for the names in the loaded
105  /// module.
106  ///
107  /// \param IsInclusionDirective Indicates that this module is being loaded
108  /// implicitly, due to the presence of an inclusion directive. Otherwise,
109  /// it is being loaded due to an import declaration.
110  ///
111  /// \returns If successful, returns the loaded module. Otherwise, returns
112  /// NULL to indicate that the module could not be loaded.
113  virtual ModuleLoadResult loadModule(SourceLocation ImportLoc,
114  ModuleIdPath Path,
116  bool IsInclusionDirective) = 0;
117 
118  /// Attempt to load the given module from the specified source buffer. Does
119  /// not make any submodule visible; for that, use loadModule or
120  /// makeModuleVisible.
121  ///
122  /// \param Loc The location at which the module was loaded.
123  /// \param ModuleName The name of the module to build.
124  /// \param Source The source of the module: a (preprocessed) module map.
125  virtual void loadModuleFromSource(SourceLocation Loc, StringRef ModuleName,
126  StringRef Source) = 0;
127 
128  /// \brief Make the given module visible.
129  virtual void makeModuleVisible(Module *Mod,
130  Module::NameVisibilityKind Visibility,
131  SourceLocation ImportLoc) = 0;
132 
133  /// \brief Load, create, or return global module.
134  /// This function returns an existing global module index, if one
135  /// had already been loaded or created, or loads one if it
136  /// exists, or creates one if it doesn't exist.
137  /// Also, importantly, if the index doesn't cover all the modules
138  /// in the module map, it will be update to do so here, because
139  /// of its use in searching for needed module imports and
140  /// associated fixit messages.
141  /// \param TriggerLoc The location for what triggered the load.
142  /// \returns Returns null if load failed.
143  virtual GlobalModuleIndex *loadGlobalModuleIndex(
144  SourceLocation TriggerLoc) = 0;
145 
146  /// Check global module index for missing imports.
147  /// \param Name The symbol name to look for.
148  /// \param TriggerLoc The location for what triggered the load.
149  /// \returns Returns true if any modules with that symbol found.
150  virtual bool lookupMissingImports(StringRef Name,
151  SourceLocation TriggerLoc) = 0;
152 
153  bool HadFatalFailure = false;
154 };
155 
156 /// A module loader that doesn't know how to load modules.
158 public:
161  bool IsInclusionDirective) override {
162  return {};
163  }
164 
165  void loadModuleFromSource(SourceLocation ImportLoc, StringRef ModuleName,
166  StringRef Source) override {}
167 
169  SourceLocation ImportLoc) override {}
170 
172  return nullptr;
173  }
174 
175  bool lookupMissingImports(StringRef Name,
176  SourceLocation TriggerLoc) override {
177  return false;
178  }
179 };
180 
181 } // namespace clang
182 
183 #endif // LLVM_CLANG_LEX_MODULELOADER_H
bool buildingModule() const
Returns true if this instance is building a module.
Definition: ModuleLoader.h:85
Defines the clang::Module class, which describes a module in the source code.
A module loader that doesn&#39;t know how to load modules.
Definition: ModuleLoader.h:157
Describes a module or submodule.
Definition: Module.h:65
Forward-declares and imports various common LLVM datatypes that clang wants to use unqualified...
Visibility
Describes the different kinds of visibility that a declaration may have.
Definition: Visibility.h:32
ModuleLoadResult(LoadResultKind Kind)
Definition: ModuleLoader.h:54
ModuleLoader(bool BuildingModule=false)
Definition: ModuleLoader.h:79
Describes the result of attempting to load a module.
Definition: ModuleLoader.h:36
ModuleLoadResult loadModule(SourceLocation ImportLoc, ModuleIdPath Path, Module::NameVisibilityKind Visibility, bool IsInclusionDirective) override
Attempt to load the given module.
Definition: ModuleLoader.h:159
GlobalModuleIndex * loadGlobalModuleIndex(SourceLocation TriggerLoc) override
Load, create, or return global module.
Definition: ModuleLoader.h:171
void loadModuleFromSource(SourceLocation ImportLoc, StringRef ModuleName, StringRef Source) override
Attempt to load the given module from the specified source buffer.
Definition: ModuleLoader.h:165
Kind
Encodes a location in the source.
bool isConfigMismatch() const
Determines whether the module failed to load due to a configuration mismatch with an explicitly-named...
Definition: ModuleLoader.h:66
A global index for a set of module files, providing information about the identifiers within those mo...
Dataflow Directional Tag Classes.
bool isMissingExpected() const
Determines whether the module, which failed to load, was actually a submodule that we expected to see...
Definition: ModuleLoader.h:62
llvm::PointerIntPair< Module *, 2, LoadResultKind > Storage
Definition: ModuleLoader.h:50
Abstract interface for a module loader.
Definition: ModuleLoader.h:74
Defines the clang::SourceLocation class and associated facilities.
NameVisibilityKind
Describes the visibility of the various names within a particular module.
Definition: Module.h:260
void setBuildingModule(bool BuildingModuleFlag)
Flag indicating whether this instance is building a module.
Definition: ModuleLoader.h:90
bool lookupMissingImports(StringRef Name, SourceLocation TriggerLoc) override
Check global module index for missing imports.
Definition: ModuleLoader.h:175
ModuleLoadResult(Module *M)
Definition: ModuleLoader.h:53
void makeModuleVisible(Module *Mod, Module::NameVisibilityKind Visibility, SourceLocation ImportLoc) override
Make the given module visible.
Definition: ModuleLoader.h:168