1 //===- CallGraphUpdater.h - A (lazy) call graph update helper ---*- 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 /// \file 9 /// 10 /// This file provides interfaces used to manipulate a call graph, regardless 11 /// if it is a "old style" CallGraph or an "new style" LazyCallGraph. 12 /// 13 //===----------------------------------------------------------------------===// 14 15 #ifndef LLVM_TRANSFORMS_UTILS_CALLGRAPHUPDATER_H 16 #define LLVM_TRANSFORMS_UTILS_CALLGRAPHUPDATER_H 17 18 #include "llvm/Analysis/CGSCCPassManager.h" 19 #include "llvm/Analysis/LazyCallGraph.h" 20 21 namespace llvm { 22 23 class CallGraph; 24 class CallGraphSCC; 25 26 /// Wrapper to unify "old style" CallGraph and "new style" LazyCallGraph. This 27 /// simplifies the interface and the call sites, e.g., new and old pass manager 28 /// passes can share the same code. 29 class CallGraphUpdater { 30 /// Containers for functions which we did replace or want to delete when 31 /// `finalize` is called. This can happen explicitly or as part of the 32 /// destructor. Dead functions in comdat sections are tracked separately 33 /// because a function with discardable linakage in a COMDAT should only 34 /// be dropped if the entire COMDAT is dropped, see git ac07703842cf. 35 ///{ 36 SmallPtrSet<Function *, 16> ReplacedFunctions; 37 SmallVector<Function *, 16> DeadFunctions; 38 SmallVector<Function *, 16> DeadFunctionsInComdats; 39 ///} 40 41 /// New PM variables 42 ///{ 43 LazyCallGraph *LCG = nullptr; 44 LazyCallGraph::SCC *SCC = nullptr; 45 CGSCCAnalysisManager *AM = nullptr; 46 CGSCCUpdateResult *UR = nullptr; 47 FunctionAnalysisManager *FAM = nullptr; 48 ///} 49 50 public: 51 CallGraphUpdater() = default; ~CallGraphUpdater()52 ~CallGraphUpdater() { finalize(); } 53 54 /// Initializers for usage outside of a CGSCC pass, inside a CGSCC pass in 55 /// the old and new pass manager (PM). 56 ///{ initialize(LazyCallGraph & LCG,LazyCallGraph::SCC & SCC,CGSCCAnalysisManager & AM,CGSCCUpdateResult & UR)57 void initialize(LazyCallGraph &LCG, LazyCallGraph::SCC &SCC, 58 CGSCCAnalysisManager &AM, CGSCCUpdateResult &UR) { 59 this->LCG = &LCG; 60 this->SCC = &SCC; 61 this->AM = &AM; 62 this->UR = &UR; 63 FAM = 64 &AM.getResult<FunctionAnalysisManagerCGSCCProxy>(SCC, LCG).getManager(); 65 } 66 ///} 67 68 /// Finalizer that will trigger actions like function removal from the CG. 69 bool finalize(); 70 71 /// Remove \p Fn from the call graph. 72 void removeFunction(Function &Fn); 73 74 /// After an CGSCC pass changes a function in ways that affect the call 75 /// graph, this method can be called to update it. 76 void reanalyzeFunction(Function &Fn); 77 78 /// If a new function was created by outlining, this method can be called 79 /// to update the call graph for the new function. Note that the old one 80 /// still needs to be re-analyzed or manually updated. 81 void registerOutlinedFunction(Function &OriginalFn, Function &NewFn); 82 83 /// Replace \p OldFn in the call graph (and SCC) with \p NewFn. The uses 84 /// outside the call graph and the function \p OldFn are not modified. 85 /// Note that \p OldFn is also removed from the call graph 86 /// (\see removeFunction). 87 void replaceFunctionWith(Function &OldFn, Function &NewFn); 88 }; 89 90 } // end namespace llvm 91 92 #endif // LLVM_TRANSFORMS_UTILS_CALLGRAPHUPDATER_H 93