//===- FunctionImportUtils.h - Importing support utilities -----*- C++ -*-===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // This file defines the FunctionImportGlobalProcessing class which is used // to perform the necessary global value handling for function importing. // //===----------------------------------------------------------------------===// #ifndef LLVM_TRANSFORMS_UTILS_FUNCTIONIMPORTUTILS_H #define LLVM_TRANSFORMS_UTILS_FUNCTIONIMPORTUTILS_H #include "llvm/ADT/SetVector.h" #include "llvm/IR/ModuleSummaryIndex.h" namespace llvm { class Module; /// Class to handle necessary GlobalValue changes required by ThinLTO /// function importing, including linkage changes and any necessary renaming. class FunctionImportGlobalProcessing { /// The Module which we are exporting or importing functions from. Module &M; /// Module summary index passed in for function importing/exporting handling. const ModuleSummaryIndex &ImportIndex; /// Globals to import from this module, all other functions will be /// imported as declarations instead of definitions. DenseSet<const GlobalValue *> *GlobalsToImport; /// Set to true if the given ModuleSummaryIndex contains any functions /// from this source module, in which case we must conservatively assume /// that any of its functions may be imported into another module /// as part of a different backend compilation process. bool HasExportedFunctions = false; /// Check if we should promote the given local value to global scope. bool doPromoteLocalToGlobal(const GlobalValue *SGV); /// Helper methods to check if we are importing from or potentially /// exporting from the current source module. bool isPerformingImport() const { return GlobalsToImport != nullptr; } bool isModuleExporting() const { return HasExportedFunctions; } /// If we are importing from the source module, checks if we should /// import SGV as a definition, otherwise import as a declaration. bool doImportAsDefinition(const GlobalValue *SGV); /// Get the name for SGV that should be used in the linked destination /// module. Specifically, this handles the case where we need to rename /// a local that is being promoted to global scope. std::string getName(const GlobalValue *SGV); /// Process globals so that they can be used in ThinLTO. This includes /// promoting local variables so that they can be reference externally by /// thin lto imported globals and converting strong external globals to /// available_externally. void processGlobalsForThinLTO(); void processGlobalForThinLTO(GlobalValue &GV); /// Get the new linkage for SGV that should be used in the linked destination /// module. Specifically, for ThinLTO importing or exporting it may need /// to be adjusted. GlobalValue::LinkageTypes getLinkage(const GlobalValue *SGV); public: FunctionImportGlobalProcessing( Module &M, const ModuleSummaryIndex &Index, DenseSet<const GlobalValue *> *GlobalsToImport = nullptr) : M(M), ImportIndex(Index), GlobalsToImport(GlobalsToImport) { // If we have a ModuleSummaryIndex but no function to import, // then this is the primary module being compiled in a ThinLTO // backend compilation, and we need to see if it has functions that // may be exported to another backend compilation. if (!GlobalsToImport) HasExportedFunctions = ImportIndex.hasExportedFunctions(M); } bool run(); static bool doImportAsDefinition(const GlobalValue *SGV, DenseSet<const GlobalValue *> *GlobalsToImport); }; /// Perform in-place global value handling on the given Module for /// exported local functions renamed and promoted for ThinLTO. bool renameModuleForThinLTO( Module &M, const ModuleSummaryIndex &Index, DenseSet<const GlobalValue *> *GlobalsToImport = nullptr); } // End llvm namespace #endif