//===- ModuleLoader.h - Module Loader Interface -----------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file defines the ModuleLoader interface, which is responsible for
// loading named modules.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CLANG_LEX_MODULELOADER_H
#define LLVM_CLANG_LEX_MODULELOADER_H
#include "clang/Basic/LLVM.h"
#include "clang/Basic/Module.h"
#include "clang/Basic/SourceLocation.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/PointerIntPair.h"
#include "llvm/ADT/StringRef.h"
#include <utility>
namespace clang {
class GlobalModuleIndex;
class IdentifierInfo;
/// A sequence of identifier/location pairs used to describe a particular
/// module or submodule, e.g., std.vector.
using ModuleIdPath = ArrayRef<std::pair<IdentifierInfo *, SourceLocation>>;
/// Describes the result of attempting to load a module.
class ModuleLoadResult {
public:
enum LoadResultKind {
// We either succeeded or failed to load the named module.
Normal,
// The module exists, but does not actually contain the named submodule.
// This should only happen if the named submodule was inferred from an
// umbrella directory, but not actually part of the umbrella header.
MissingExpected,
// The module exists but cannot be imported due to a configuration mismatch.
ConfigMismatch,
};
llvm::PointerIntPair<Module *, 2, LoadResultKind> Storage;
ModuleLoadResult() = default;
ModuleLoadResult(Module *M) : Storage(M, Normal) {}
ModuleLoadResult(LoadResultKind Kind) : Storage(nullptr, Kind) {}
ModuleLoadResult(Module *M, LoadResultKind Kind) : Storage(M, Kind) {}
operator bool() const {
return Storage.getInt() == Normal && Storage.getPointer();
}
operator Module *() const { return Storage.getPointer(); }
/// Determines whether this is a normal return, whether or not loading the
/// module was successful.
bool isNormal() const { return Storage.getInt() == Normal; }
/// Determines whether the module, which failed to load, was
/// actually a submodule that we expected to see (based on implying the
/// submodule from header structure), but didn't materialize in the actual
/// module.
bool isMissingExpected() const { return Storage.getInt() == MissingExpected; }
/// Determines whether the module failed to load due to a configuration
/// mismatch with an explicitly-named .pcm file from the command line.
bool isConfigMismatch() const { return Storage.getInt() == ConfigMismatch; }
};
/// Abstract interface for a module loader.
///
/// This abstract interface describes a module loader, which is responsible
/// for resolving a module name (e.g., "std") to an actual module file, and
/// then loading that module.
class ModuleLoader {
// Building a module if true.
bool BuildingModule;
public:
explicit ModuleLoader(bool BuildingModule = false)
: BuildingModule(BuildingModule) {}
virtual ~ModuleLoader();
/// Returns true if this instance is building a module.
bool buildingModule() const {
return BuildingModule;
}
/// Flag indicating whether this instance is building a module.
void setBuildingModule(bool BuildingModuleFlag) {
BuildingModule = BuildingModuleFlag;
}
/// Attempt to load the given module.
///
/// This routine attempts to load the module described by the given
/// parameters. If there is a module cache, this may implicitly compile the
/// module before loading it.
///
/// \param ImportLoc The location of the 'import' keyword.
///
/// \param Path The identifiers (and their locations) of the module
/// "path", e.g., "std.vector" would be split into "std" and "vector".
///
/// \param Visibility The visibility provided for the names in the loaded
/// module.
///
/// \param IsInclusionDirective Indicates that this module is being loaded
/// implicitly, due to the presence of an inclusion directive. Otherwise,
/// it is being loaded due to an import declaration.
///
/// \returns If successful, returns the loaded module. Otherwise, returns
/// NULL to indicate that the module could not be loaded.
virtual ModuleLoadResult loadModule(SourceLocation ImportLoc,
ModuleIdPath Path,
Module::NameVisibilityKind Visibility,
bool IsInclusionDirective) = 0;
/// Attempt to create the given module from the specified source buffer.
/// Does not load the module or make any submodule visible; for that, use
/// loadModule and makeModuleVisible.
///
/// \param Loc The location at which to create the module.
/// \param ModuleName The name of the module to create.
/// \param Source The source of the module: a (preprocessed) module map.
virtual void createModuleFromSource(SourceLocation Loc, StringRef ModuleName,
StringRef Source) = 0;
/// Make the given module visible.
virtual void makeModuleVisible(Module *Mod,
Module::NameVisibilityKind Visibility,
SourceLocation ImportLoc) = 0;
/// Load, create, or return global module.
/// This function returns an existing global module index, if one
/// had already been loaded or created, or loads one if it
/// exists, or creates one if it doesn't exist.
/// Also, importantly, if the index doesn't cover all the modules
/// in the module map, it will be update to do so here, because
/// of its use in searching for needed module imports and
/// associated fixit messages.
/// \param TriggerLoc The location for what triggered the load.
/// \returns Returns null if load failed.
virtual GlobalModuleIndex *loadGlobalModuleIndex(
SourceLocation TriggerLoc) = 0;
/// Check global module index for missing imports.
/// \param Name The symbol name to look for.
/// \param TriggerLoc The location for what triggered the load.
/// \returns Returns true if any modules with that symbol found.
virtual bool lookupMissingImports(StringRef Name,
SourceLocation TriggerLoc) = 0;
bool HadFatalFailure = false;
};
/// A module loader that doesn't know how to create or load modules.
class TrivialModuleLoader : public ModuleLoader {
public:
ModuleLoadResult loadModule(SourceLocation ImportLoc, ModuleIdPath Path,
Module::NameVisibilityKind Visibility,
bool IsInclusionDirective) override {
return {};
}
void createModuleFromSource(SourceLocation ImportLoc, StringRef ModuleName,
StringRef Source) override {}
void makeModuleVisible(Module *Mod, Module::NameVisibilityKind Visibility,
SourceLocation ImportLoc) override {}
GlobalModuleIndex *loadGlobalModuleIndex(SourceLocation TriggerLoc) override {
return nullptr;
}
bool lookupMissingImports(StringRef Name,
SourceLocation TriggerLoc) override {
return false;
}
};
} // namespace clang
#endif // LLVM_CLANG_LEX_MODULELOADER_H