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ModuleLoader.h
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1 //===- ModuleLoader.h - Module Loader Interface -----------------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file defines the ModuleLoader interface, which is responsible for
10 // loading named modules.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_CLANG_LEX_MODULELOADER_H
15 #define LLVM_CLANG_LEX_MODULELOADER_H
16 
17 #include "clang/Basic/LLVM.h"
18 #include "clang/Basic/Module.h"
20 #include "llvm/ADT/ArrayRef.h"
21 #include "llvm/ADT/PointerIntPair.h"
22 #include "llvm/ADT/StringRef.h"
23 #include <utility>
24 
25 namespace clang {
26 
27 class GlobalModuleIndex;
28 class IdentifierInfo;
29 
30 /// A sequence of identifier/location pairs used to describe a particular
31 /// module or submodule, e.g., std.vector.
33 
34 /// Describes the result of attempting to load a module.
36 public:
38  // We either succeeded or failed to load the named module.
40 
41  // The module exists, but does not actually contain the named submodule.
42  // This should only happen if the named submodule was inferred from an
43  // umbrella directory, but not actually part of the umbrella header.
45 
46  // The module exists but cannot be imported due to a configuration mismatch.
48  };
49  llvm::PointerIntPair<Module *, 2, LoadResultKind> Storage;
50 
51  ModuleLoadResult() = default;
52  ModuleLoadResult(Module *M) : Storage(M, Normal) {}
53  ModuleLoadResult(LoadResultKind Kind) : Storage(nullptr, Kind) {}
54 
55  operator Module *() const { return Storage.getPointer(); }
56 
57  /// Determines whether the module, which failed to load, was
58  /// actually a submodule that we expected to see (based on implying the
59  /// submodule from header structure), but didn't materialize in the actual
60  /// module.
61  bool isMissingExpected() const { return Storage.getInt() == MissingExpected; }
62 
63  /// Determines whether the module failed to load due to a configuration
64  /// mismatch with an explicitly-named .pcm file from the command line.
65  bool isConfigMismatch() const { return Storage.getInt() == ConfigMismatch; }
66 };
67 
68 /// Abstract interface for a module loader.
69 ///
70 /// This abstract interface describes a module loader, which is responsible
71 /// for resolving a module name (e.g., "std") to an actual module file, and
72 /// then loading that module.
73 class ModuleLoader {
74  // Building a module if true.
75  bool BuildingModule;
76 
77 public:
78  explicit ModuleLoader(bool BuildingModule = false)
79  : BuildingModule(BuildingModule) {}
80 
81  virtual ~ModuleLoader();
82 
83  /// Returns true if this instance is building a module.
84  bool buildingModule() const {
85  return BuildingModule;
86  }
87 
88  /// Flag indicating whether this instance is building a module.
89  void setBuildingModule(bool BuildingModuleFlag) {
90  BuildingModule = BuildingModuleFlag;
91  }
92 
93  /// Attempt to load the given module.
94  ///
95  /// This routine attempts to load the module described by the given
96  /// parameters.
97  ///
98  /// \param ImportLoc The location of the 'import' keyword.
99  ///
100  /// \param Path The identifiers (and their locations) of the module
101  /// "path", e.g., "std.vector" would be split into "std" and "vector".
102  ///
103  /// \param Visibility The visibility provided for the names in the loaded
104  /// module.
105  ///
106  /// \param IsInclusionDirective Indicates that this module is being loaded
107  /// implicitly, due to the presence of an inclusion directive. Otherwise,
108  /// it is being loaded due to an import declaration.
109  ///
110  /// \returns If successful, returns the loaded module. Otherwise, returns
111  /// NULL to indicate that the module could not be loaded.
112  virtual ModuleLoadResult loadModule(SourceLocation ImportLoc,
113  ModuleIdPath Path,
115  bool IsInclusionDirective) = 0;
116 
117  /// Attempt to load the given module from the specified source buffer. Does
118  /// not make any submodule visible; for that, use loadModule or
119  /// makeModuleVisible.
120  ///
121  /// \param Loc The location at which the module was loaded.
122  /// \param ModuleName The name of the module to build.
123  /// \param Source The source of the module: a (preprocessed) module map.
124  virtual void loadModuleFromSource(SourceLocation Loc, StringRef ModuleName,
125  StringRef Source) = 0;
126 
127  /// Make the given module visible.
128  virtual void makeModuleVisible(Module *Mod,
129  Module::NameVisibilityKind Visibility,
130  SourceLocation ImportLoc) = 0;
131 
132  /// Load, create, or return global module.
133  /// This function returns an existing global module index, if one
134  /// had already been loaded or created, or loads one if it
135  /// exists, or creates one if it doesn't exist.
136  /// Also, importantly, if the index doesn't cover all the modules
137  /// in the module map, it will be update to do so here, because
138  /// of its use in searching for needed module imports and
139  /// associated fixit messages.
140  /// \param TriggerLoc The location for what triggered the load.
141  /// \returns Returns null if load failed.
142  virtual GlobalModuleIndex *loadGlobalModuleIndex(
143  SourceLocation TriggerLoc) = 0;
144 
145  /// Check global module index for missing imports.
146  /// \param Name The symbol name to look for.
147  /// \param TriggerLoc The location for what triggered the load.
148  /// \returns Returns true if any modules with that symbol found.
149  virtual bool lookupMissingImports(StringRef Name,
150  SourceLocation TriggerLoc) = 0;
151 
152  bool HadFatalFailure = false;
153 };
154 
155 /// A module loader that doesn't know how to load modules.
157 public:
160  bool IsInclusionDirective) override {
161  return {};
162  }
163 
164  void loadModuleFromSource(SourceLocation ImportLoc, StringRef ModuleName,
165  StringRef Source) override {}
166 
168  SourceLocation ImportLoc) override {}
169 
171  return nullptr;
172  }
173 
174  bool lookupMissingImports(StringRef Name,
175  SourceLocation TriggerLoc) override {
176  return false;
177  }
178 };
179 
180 } // namespace clang
181 
182 #endif // LLVM_CLANG_LEX_MODULELOADER_H
bool buildingModule() const
Returns true if this instance is building a module.
Definition: ModuleLoader.h:84
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:156
Describes a module or submodule.
Definition: Module.h:64
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:33
ModuleLoadResult(LoadResultKind Kind)
Definition: ModuleLoader.h:53
ModuleLoader(bool BuildingModule=false)
Definition: ModuleLoader.h:78
Describes the result of attempting to load a module.
Definition: ModuleLoader.h:35
ModuleLoadResult loadModule(SourceLocation ImportLoc, ModuleIdPath Path, Module::NameVisibilityKind Visibility, bool IsInclusionDirective) override
Attempt to load the given module.
Definition: ModuleLoader.h:158
GlobalModuleIndex * loadGlobalModuleIndex(SourceLocation TriggerLoc) override
Load, create, or return global module.
Definition: ModuleLoader.h:170
void loadModuleFromSource(SourceLocation ImportLoc, StringRef ModuleName, StringRef Source) override
Attempt to load the given module from the specified source buffer.
Definition: ModuleLoader.h:164
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:65
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:61
llvm::PointerIntPair< Module *, 2, LoadResultKind > Storage
Definition: ModuleLoader.h:49
Abstract interface for a module loader.
Definition: ModuleLoader.h:73
Defines the clang::SourceLocation class and associated facilities.
NameVisibilityKind
Describes the visibility of the various names within a particular module.
Definition: Module.h:273
void setBuildingModule(bool BuildingModuleFlag)
Flag indicating whether this instance is building a module.
Definition: ModuleLoader.h:89
bool lookupMissingImports(StringRef Name, SourceLocation TriggerLoc) override
Check global module index for missing imports.
Definition: ModuleLoader.h:174
ModuleLoadResult(Module *M)
Definition: ModuleLoader.h:52
void makeModuleVisible(Module *Mod, Module::NameVisibilityKind Visibility, SourceLocation ImportLoc) override
Make the given module visible.
Definition: ModuleLoader.h:167