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/IdentifierTable.h" 18 #include "clang/Basic/LLVM.h" 19 #include "clang/Basic/Module.h" 20 #include "clang/Basic/SourceLocation.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 /// A sequence of identifier/location pairs used to describe a particular 32 /// module or submodule, e.g., std.vector. 33 using ModuleIdPath = ArrayRef<IdentifierLoc>; 34 35 /// Describes the result of attempting to load a module. 36 class ModuleLoadResult { 37 public: 38 enum LoadResultKind { 39 // We either succeeded or failed to load the named module. 40 Normal, 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. 45 MissingExpected, 46 47 // The module exists but cannot be imported due to a configuration mismatch. 48 ConfigMismatch, 49 }; 50 llvm::PointerIntPair<Module *, 2, LoadResultKind> Storage; 51 52 ModuleLoadResult() = default; ModuleLoadResult(Module * M)53 ModuleLoadResult(Module *M) : Storage(M, Normal) {} ModuleLoadResult(LoadResultKind Kind)54 ModuleLoadResult(LoadResultKind Kind) : Storage(nullptr, Kind) {} ModuleLoadResult(Module * M,LoadResultKind Kind)55 ModuleLoadResult(Module *M, LoadResultKind Kind) : Storage(M, Kind) {} 56 57 operator bool() const { 58 return Storage.getInt() == Normal && Storage.getPointer(); 59 } 60 61 operator Module *() const { return Storage.getPointer(); } 62 63 /// Determines whether this is a normal return, whether or not loading the 64 /// module was successful. isNormal()65 bool isNormal() const { return Storage.getInt() == Normal; } 66 67 /// Determines whether the module, which failed to load, was 68 /// actually a submodule that we expected to see (based on implying the 69 /// submodule from header structure), but didn't materialize in the actual 70 /// module. isMissingExpected()71 bool isMissingExpected() const { return Storage.getInt() == MissingExpected; } 72 73 /// Determines whether the module failed to load due to a configuration 74 /// mismatch with an explicitly-named .pcm file from the command line. isConfigMismatch()75 bool isConfigMismatch() const { return Storage.getInt() == ConfigMismatch; } 76 }; 77 78 /// Abstract interface for a module loader. 79 /// 80 /// This abstract interface describes a module loader, which is responsible 81 /// for resolving a module name (e.g., "std") to an actual module file, and 82 /// then loading that module. 83 class ModuleLoader { 84 // Building a module if true. 85 bool BuildingModule; 86 87 public: 88 explicit ModuleLoader(bool BuildingModule = false) BuildingModule(BuildingModule)89 : BuildingModule(BuildingModule) {} 90 91 virtual ~ModuleLoader(); 92 93 /// Returns true if this instance is building a module. buildingModule()94 bool buildingModule() const { 95 return BuildingModule; 96 } 97 98 /// Flag indicating whether this instance is building a module. setBuildingModule(bool BuildingModuleFlag)99 void setBuildingModule(bool BuildingModuleFlag) { 100 BuildingModule = BuildingModuleFlag; 101 } 102 103 /// Attempt to load the given module. 104 /// 105 /// This routine attempts to load the module described by the given 106 /// parameters. If there is a module cache, this may implicitly compile the 107 /// module before loading it. 108 /// 109 /// \param ImportLoc The location of the 'import' keyword. 110 /// 111 /// \param Path The identifiers (and their locations) of the module 112 /// "path", e.g., "std.vector" would be split into "std" and "vector". 113 /// 114 /// \param Visibility The visibility provided for the names in the loaded 115 /// module. 116 /// 117 /// \param IsInclusionDirective Indicates that this module is being loaded 118 /// implicitly, due to the presence of an inclusion directive. Otherwise, 119 /// it is being loaded due to an import declaration. 120 /// 121 /// \returns If successful, returns the loaded module. Otherwise, returns 122 /// NULL to indicate that the module could not be loaded. 123 virtual ModuleLoadResult loadModule(SourceLocation ImportLoc, 124 ModuleIdPath Path, 125 Module::NameVisibilityKind Visibility, 126 bool IsInclusionDirective) = 0; 127 128 /// Attempt to create the given module from the specified source buffer. 129 /// Does not load the module or make any submodule visible; for that, use 130 /// loadModule and makeModuleVisible. 131 /// 132 /// \param Loc The location at which to create the module. 133 /// \param ModuleName The name of the module to create. 134 /// \param Source The source of the module: a (preprocessed) module map. 135 virtual void createModuleFromSource(SourceLocation Loc, StringRef ModuleName, 136 StringRef Source) = 0; 137 138 /// Make the given module visible. 139 virtual void makeModuleVisible(Module *Mod, 140 Module::NameVisibilityKind Visibility, 141 SourceLocation ImportLoc) = 0; 142 143 /// Load, create, or return global module. 144 /// This function returns an existing global module index, if one 145 /// had already been loaded or created, or loads one if it 146 /// exists, or creates one if it doesn't exist. 147 /// Also, importantly, if the index doesn't cover all the modules 148 /// in the module map, it will be update to do so here, because 149 /// of its use in searching for needed module imports and 150 /// associated fixit messages. 151 /// \param TriggerLoc The location for what triggered the load. 152 /// \returns Returns null if load failed. 153 virtual GlobalModuleIndex *loadGlobalModuleIndex( 154 SourceLocation TriggerLoc) = 0; 155 156 /// Check global module index for missing imports. 157 /// \param Name The symbol name to look for. 158 /// \param TriggerLoc The location for what triggered the load. 159 /// \returns Returns true if any modules with that symbol found. 160 virtual bool lookupMissingImports(StringRef Name, 161 SourceLocation TriggerLoc) = 0; 162 163 bool HadFatalFailure = false; 164 }; 165 166 /// A module loader that doesn't know how to create or load modules. 167 class TrivialModuleLoader : public ModuleLoader { 168 public: loadModule(SourceLocation ImportLoc,ModuleIdPath Path,Module::NameVisibilityKind Visibility,bool IsInclusionDirective)169 ModuleLoadResult loadModule(SourceLocation ImportLoc, ModuleIdPath Path, 170 Module::NameVisibilityKind Visibility, 171 bool IsInclusionDirective) override { 172 return {}; 173 } 174 createModuleFromSource(SourceLocation ImportLoc,StringRef ModuleName,StringRef Source)175 void createModuleFromSource(SourceLocation ImportLoc, StringRef ModuleName, 176 StringRef Source) override {} 177 makeModuleVisible(Module * Mod,Module::NameVisibilityKind Visibility,SourceLocation ImportLoc)178 void makeModuleVisible(Module *Mod, Module::NameVisibilityKind Visibility, 179 SourceLocation ImportLoc) override {} 180 loadGlobalModuleIndex(SourceLocation TriggerLoc)181 GlobalModuleIndex *loadGlobalModuleIndex(SourceLocation TriggerLoc) override { 182 return nullptr; 183 } 184 lookupMissingImports(StringRef Name,SourceLocation TriggerLoc)185 bool lookupMissingImports(StringRef Name, 186 SourceLocation TriggerLoc) override { 187 return false; 188 } 189 }; 190 191 } // namespace clang 192 193 #endif // LLVM_CLANG_LEX_MODULELOADER_H 194