clang  12.0.0git
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  // We failed to load the module, but we shouldn't cache the failure.
51  };
52  llvm::PointerIntPair<Module *, 2, LoadResultKind> Storage;
53 
54  ModuleLoadResult() = default;
55  ModuleLoadResult(Module *M) : Storage(M, Normal) {}
56  ModuleLoadResult(LoadResultKind Kind) : Storage(nullptr, Kind) {}
57 
58  operator Module *() const { return Storage.getPointer(); }
59 
60  /// Determines whether this is a normal return, whether or not loading the
61  /// module was successful.
62  bool isNormal() const { return Storage.getInt() == Normal; }
63 
64  /// Determines whether the module, which failed to load, was
65  /// actually a submodule that we expected to see (based on implying the
66  /// submodule from header structure), but didn't materialize in the actual
67  /// module.
68  bool isMissingExpected() const { return Storage.getInt() == MissingExpected; }
69 
70  /// Determines whether the module failed to load due to a configuration
71  /// mismatch with an explicitly-named .pcm file from the command line.
72  bool isConfigMismatch() const { return Storage.getInt() == ConfigMismatch; }
73 };
74 
75 /// Abstract interface for a module loader.
76 ///
77 /// This abstract interface describes a module loader, which is responsible
78 /// for resolving a module name (e.g., "std") to an actual module file, and
79 /// then loading that module.
80 class ModuleLoader {
81  // Building a module if true.
82  bool BuildingModule;
83 
84 public:
85  explicit ModuleLoader(bool BuildingModule = false)
86  : BuildingModule(BuildingModule) {}
87 
88  virtual ~ModuleLoader();
89 
90  /// Returns true if this instance is building a module.
91  bool buildingModule() const {
92  return BuildingModule;
93  }
94 
95  /// Flag indicating whether this instance is building a module.
96  void setBuildingModule(bool BuildingModuleFlag) {
97  BuildingModule = BuildingModuleFlag;
98  }
99 
100  /// Attempt to load the given module.
101  ///
102  /// This routine attempts to load the module described by the given
103  /// parameters. If there is a module cache, this may implicitly compile the
104  /// module before loading it.
105  ///
106  /// \param ImportLoc The location of the 'import' keyword.
107  ///
108  /// \param Path The identifiers (and their locations) of the module
109  /// "path", e.g., "std.vector" would be split into "std" and "vector".
110  ///
111  /// \param Visibility The visibility provided for the names in the loaded
112  /// module.
113  ///
114  /// \param IsInclusionDirective Indicates that this module is being loaded
115  /// implicitly, due to the presence of an inclusion directive. Otherwise,
116  /// it is being loaded due to an import declaration.
117  ///
118  /// \returns If successful, returns the loaded module. Otherwise, returns
119  /// NULL to indicate that the module could not be loaded.
120  virtual ModuleLoadResult loadModule(SourceLocation ImportLoc,
121  ModuleIdPath Path,
123  bool IsInclusionDirective) = 0;
124 
125  /// Attempt to create the given module from the specified source buffer.
126  /// Does not load the module or make any submodule visible; for that, use
127  /// loadModule and makeModuleVisible.
128  ///
129  /// \param Loc The location at which to create the module.
130  /// \param ModuleName The name of the module to create.
131  /// \param Source The source of the module: a (preprocessed) module map.
132  virtual void createModuleFromSource(SourceLocation Loc, StringRef ModuleName,
133  StringRef Source) = 0;
134 
135  /// Make the given module visible.
136  virtual void makeModuleVisible(Module *Mod,
137  Module::NameVisibilityKind Visibility,
138  SourceLocation ImportLoc) = 0;
139 
140  /// Load, create, or return global module.
141  /// This function returns an existing global module index, if one
142  /// had already been loaded or created, or loads one if it
143  /// exists, or creates one if it doesn't exist.
144  /// Also, importantly, if the index doesn't cover all the modules
145  /// in the module map, it will be update to do so here, because
146  /// of its use in searching for needed module imports and
147  /// associated fixit messages.
148  /// \param TriggerLoc The location for what triggered the load.
149  /// \returns Returns null if load failed.
150  virtual GlobalModuleIndex *loadGlobalModuleIndex(
151  SourceLocation TriggerLoc) = 0;
152 
153  /// Check global module index for missing imports.
154  /// \param Name The symbol name to look for.
155  /// \param TriggerLoc The location for what triggered the load.
156  /// \returns Returns true if any modules with that symbol found.
157  virtual bool lookupMissingImports(StringRef Name,
158  SourceLocation TriggerLoc) = 0;
159 
160  bool HadFatalFailure = false;
161 };
162 
163 /// A module loader that doesn't know how to create or load modules.
165 public:
168  bool IsInclusionDirective) override {
169  return {};
170  }
171 
172  void createModuleFromSource(SourceLocation ImportLoc, StringRef ModuleName,
173  StringRef Source) override {}
174 
176  SourceLocation ImportLoc) override {}
177 
179  return nullptr;
180  }
181 
182  bool lookupMissingImports(StringRef Name,
183  SourceLocation TriggerLoc) override {
184  return false;
185  }
186 };
187 
188 } // namespace clang
189 
190 #endif // LLVM_CLANG_LEX_MODULELOADER_H
bool buildingModule() const
Returns true if this instance is building a module.
Definition: ModuleLoader.h:91
A module loader that doesn&#39;t know how to create or load modules.
Definition: ModuleLoader.h:164
Describes a module or submodule.
Definition: Module.h:87
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:56
ModuleLoader(bool BuildingModule=false)
Definition: ModuleLoader.h:85
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:166
GlobalModuleIndex * loadGlobalModuleIndex(SourceLocation TriggerLoc) override
Load, create, or return global module.
Definition: ModuleLoader.h:178
bool isNormal() const
Determines whether this is a normal return, whether or not loading the module was successful...
Definition: ModuleLoader.h:62
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:72
Defines the clang::Module class, which describes a module in the source code.
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:68
llvm::PointerIntPair< Module *, 2, LoadResultKind > Storage
Definition: ModuleLoader.h:52
void createModuleFromSource(SourceLocation ImportLoc, StringRef ModuleName, StringRef Source) override
Attempt to create the given module from the specified source buffer.
Definition: ModuleLoader.h:172
Abstract interface for a module loader.
Definition: ModuleLoader.h:80
Defines the clang::SourceLocation class and associated facilities.
NameVisibilityKind
Describes the visibility of the various names within a particular module.
Definition: Module.h:301
void setBuildingModule(bool BuildingModuleFlag)
Flag indicating whether this instance is building a module.
Definition: ModuleLoader.h:96
bool lookupMissingImports(StringRef Name, SourceLocation TriggerLoc) override
Check global module index for missing imports.
Definition: ModuleLoader.h:182
ModuleLoadResult(Module *M)
Definition: ModuleLoader.h:55
void makeModuleVisible(Module *Mod, Module::NameVisibilityKind Visibility, SourceLocation ImportLoc) override
Make the given module visible.
Definition: ModuleLoader.h:175