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