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 // We failed to load the module, but we shouldn't cache the failure. 50 OtherUncachedFailure, 51 }; 52 llvm::PointerIntPair<Module *, 2, LoadResultKind> Storage; 53 54 ModuleLoadResult() = default; ModuleLoadResult(Module * M)55 ModuleLoadResult(Module *M) : Storage(M, Normal) {} ModuleLoadResult(LoadResultKind Kind)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. isNormal()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. isMissingExpected()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. isConfigMismatch()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) BuildingModule(BuildingModule)86 : BuildingModule(BuildingModule) {} 87 88 virtual ~ModuleLoader(); 89 90 /// Returns true if this instance is building a module. buildingModule()91 bool buildingModule() const { 92 return BuildingModule; 93 } 94 95 /// Flag indicating whether this instance is building a module. setBuildingModule(bool BuildingModuleFlag)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, 122 Module::NameVisibilityKind Visibility, 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. 164 class TrivialModuleLoader : public ModuleLoader { 165 public: loadModule(SourceLocation ImportLoc,ModuleIdPath Path,Module::NameVisibilityKind Visibility,bool IsInclusionDirective)166 ModuleLoadResult loadModule(SourceLocation ImportLoc, ModuleIdPath Path, 167 Module::NameVisibilityKind Visibility, 168 bool IsInclusionDirective) override { 169 return {}; 170 } 171 createModuleFromSource(SourceLocation ImportLoc,StringRef ModuleName,StringRef Source)172 void createModuleFromSource(SourceLocation ImportLoc, StringRef ModuleName, 173 StringRef Source) override {} 174 makeModuleVisible(Module * Mod,Module::NameVisibilityKind Visibility,SourceLocation ImportLoc)175 void makeModuleVisible(Module *Mod, Module::NameVisibilityKind Visibility, 176 SourceLocation ImportLoc) override {} 177 loadGlobalModuleIndex(SourceLocation TriggerLoc)178 GlobalModuleIndex *loadGlobalModuleIndex(SourceLocation TriggerLoc) override { 179 return nullptr; 180 } 181 lookupMissingImports(StringRef Name,SourceLocation TriggerLoc)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 191