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" 19 #include "clang/Basic/SourceLocation.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. 32 using ModuleIdPath = ArrayRef<std::pair<IdentifierInfo *, SourceLocation>>; 33 34 /// Describes the result of attempting to load a module. 35 class ModuleLoadResult { 36 public: 37 enum LoadResultKind { 38 // We either succeeded or failed to load the named module. 39 Normal, 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. 44 MissingExpected, 45 46 // The module exists but cannot be imported due to a configuration mismatch. 47 ConfigMismatch, 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 this is a normal return, whether or not loading the 58 /// module was successful. 59 bool isNormal() const { return Storage.getInt() == Normal; } 60 61 /// Determines whether the module, which failed to load, was 62 /// actually a submodule that we expected to see (based on implying the 63 /// submodule from header structure), but didn't materialize in the actual 64 /// module. 65 bool isMissingExpected() const { return Storage.getInt() == MissingExpected; } 66 67 /// Determines whether the module failed to load due to a configuration 68 /// mismatch with an explicitly-named .pcm file from the command line. 69 bool isConfigMismatch() const { return Storage.getInt() == ConfigMismatch; } 70 }; 71 72 /// Abstract interface for a module loader. 73 /// 74 /// This abstract interface describes a module loader, which is responsible 75 /// for resolving a module name (e.g., "std") to an actual module file, and 76 /// then loading that module. 77 class ModuleLoader { 78 // Building a module if true. 79 bool BuildingModule; 80 81 public: 82 explicit ModuleLoader(bool BuildingModule = false) 83 : BuildingModule(BuildingModule) {} 84 85 virtual ~ModuleLoader(); 86 87 /// Returns true if this instance is building a module. 88 bool buildingModule() const { 89 return BuildingModule; 90 } 91 92 /// Flag indicating whether this instance is building a module. 93 void setBuildingModule(bool BuildingModuleFlag) { 94 BuildingModule = BuildingModuleFlag; 95 } 96 97 /// Attempt to load the given module. 98 /// 99 /// This routine attempts to load the module described by the given 100 /// parameters. If there is a module cache, this may implicitly compile the 101 /// module before loading it. 102 /// 103 /// \param ImportLoc The location of the 'import' keyword. 104 /// 105 /// \param Path The identifiers (and their locations) of the module 106 /// "path", e.g., "std.vector" would be split into "std" and "vector". 107 /// 108 /// \param Visibility The visibility provided for the names in the loaded 109 /// module. 110 /// 111 /// \param IsInclusionDirective Indicates that this module is being loaded 112 /// implicitly, due to the presence of an inclusion directive. Otherwise, 113 /// it is being loaded due to an import declaration. 114 /// 115 /// \returns If successful, returns the loaded module. Otherwise, returns 116 /// NULL to indicate that the module could not be loaded. 117 virtual ModuleLoadResult loadModule(SourceLocation ImportLoc, 118 ModuleIdPath Path, 119 Module::NameVisibilityKind Visibility, 120 bool IsInclusionDirective) = 0; 121 122 /// Attempt to create the given module from the specified source buffer. 123 /// Does not load the module or make any submodule visible; for that, use 124 /// loadModule and makeModuleVisible. 125 /// 126 /// \param Loc The location at which to create the module. 127 /// \param ModuleName The name of the module to create. 128 /// \param Source The source of the module: a (preprocessed) module map. 129 virtual void createModuleFromSource(SourceLocation Loc, StringRef ModuleName, 130 StringRef Source) = 0; 131 132 /// Make the given module visible. 133 virtual void makeModuleVisible(Module *Mod, 134 Module::NameVisibilityKind Visibility, 135 SourceLocation ImportLoc) = 0; 136 137 /// Load, create, or return global module. 138 /// This function returns an existing global module index, if one 139 /// had already been loaded or created, or loads one if it 140 /// exists, or creates one if it doesn't exist. 141 /// Also, importantly, if the index doesn't cover all the modules 142 /// in the module map, it will be update to do so here, because 143 /// of its use in searching for needed module imports and 144 /// associated fixit messages. 145 /// \param TriggerLoc The location for what triggered the load. 146 /// \returns Returns null if load failed. 147 virtual GlobalModuleIndex *loadGlobalModuleIndex( 148 SourceLocation TriggerLoc) = 0; 149 150 /// Check global module index for missing imports. 151 /// \param Name The symbol name to look for. 152 /// \param TriggerLoc The location for what triggered the load. 153 /// \returns Returns true if any modules with that symbol found. 154 virtual bool lookupMissingImports(StringRef Name, 155 SourceLocation TriggerLoc) = 0; 156 157 bool HadFatalFailure = false; 158 }; 159 160 /// A module loader that doesn't know how to create or load modules. 161 class TrivialModuleLoader : public ModuleLoader { 162 public: 163 ModuleLoadResult loadModule(SourceLocation ImportLoc, ModuleIdPath Path, 164 Module::NameVisibilityKind Visibility, 165 bool IsInclusionDirective) override { 166 return {}; 167 } 168 169 void createModuleFromSource(SourceLocation ImportLoc, StringRef ModuleName, 170 StringRef Source) override {} 171 172 void makeModuleVisible(Module *Mod, Module::NameVisibilityKind Visibility, 173 SourceLocation ImportLoc) override {} 174 175 GlobalModuleIndex *loadGlobalModuleIndex(SourceLocation TriggerLoc) override { 176 return nullptr; 177 } 178 179 bool lookupMissingImports(StringRef Name, 180 SourceLocation TriggerLoc) override { 181 return false; 182 } 183 }; 184 185 } // namespace clang 186 187 #endif // LLVM_CLANG_LEX_MODULELOADER_H 188