| //====- Internalize.h - Internalization API ---------------------*- C++ -*-===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This pass loops over all of the functions and variables in the input module. |
| // If the function or variable does not need to be preserved according to the |
| // client supplied callback, it is marked as internal. |
| // |
| // This transformation would not be legal in a regular compilation, but it gets |
| // extra information from the linker about what is safe. |
| // |
| // For example: Internalizing a function with external linkage. Only if we are |
| // told it is only used from within this module, it is safe to do it. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLVM_TRANSFORMS_IPO_INTERNALIZE_H |
| #define LLVM_TRANSFORMS_IPO_INTERNALIZE_H |
| |
| #include "llvm/ADT/StringSet.h" |
| #include "llvm/IR/GlobalValue.h" |
| #include "llvm/IR/PassManager.h" |
| #include <functional> |
| #include <set> |
| |
| namespace llvm { |
| class Module; |
| class CallGraph; |
| |
| /// A pass that internalizes all functions and variables other than those that |
| /// must be preserved according to \c MustPreserveGV. |
| class InternalizePass : public PassInfoMixin<InternalizePass> { |
| /// Client supplied callback to control wheter a symbol must be preserved. |
| const std::function<bool(const GlobalValue &)> MustPreserveGV; |
| /// Set of symbols private to the compiler that this pass should not touch. |
| StringSet<> AlwaysPreserved; |
| |
| /// Return false if we're allowed to internalize this GV. |
| bool shouldPreserveGV(const GlobalValue &GV); |
| /// Internalize GV if it is possible to do so, i.e. it is not externally |
| /// visible and is not a member of an externally visible comdat. |
| bool maybeInternalize(GlobalValue &GV, |
| const std::set<const Comdat *> &ExternalComdats); |
| /// If GV is part of a comdat and is externally visible, keep track of its |
| /// comdat so that we don't internalize any of its members. |
| void checkComdatVisibility(GlobalValue &GV, |
| std::set<const Comdat *> &ExternalComdats); |
| |
| public: |
| InternalizePass(); |
| InternalizePass(std::function<bool(const GlobalValue &)> MustPreserveGV) |
| : MustPreserveGV(std::move(MustPreserveGV)) {} |
| |
| /// Run the internalizer on \p TheModule, returns true if any changes was |
| /// made. |
| /// |
| /// If the CallGraph \p CG is supplied, it will be updated when |
| /// internalizing a function (by removing any edge from the "external node") |
| bool internalizeModule(Module &TheModule, CallGraph *CG = nullptr); |
| |
| PreservedAnalyses run(Module &M, ModuleAnalysisManager &AM); |
| }; |
| |
| /// Helper function to internalize functions and variables in a Module. |
| inline bool |
| internalizeModule(Module &TheModule, |
| std::function<bool(const GlobalValue &)> MustPreserveGV, |
| CallGraph *CG = nullptr) { |
| return InternalizePass(std::move(MustPreserveGV)) |
| .internalizeModule(TheModule, CG); |
| } |
| } // end namespace llvm |
| |
| #endif // LLVM_TRANSFORMS_IPO_INTERNALIZE_H |