1 //===-- FEntryInsertion.cpp - Patchable prologues for LLVM -------------===// 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 edits function bodies to insert fentry calls. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #include "llvm/CodeGen/FEntryInserter.h" 14 #include "llvm/CodeGen/MachineFunction.h" 15 #include "llvm/CodeGen/MachineFunctionPass.h" 16 #include "llvm/CodeGen/MachineInstrBuilder.h" 17 #include "llvm/CodeGen/MachinePassManager.h" 18 #include "llvm/CodeGen/TargetInstrInfo.h" 19 #include "llvm/CodeGen/TargetSubtargetInfo.h" 20 #include "llvm/IR/Function.h" 21 #include "llvm/InitializePasses.h" 22 23 using namespace llvm; 24 25 namespace { 26 struct FEntryInserter { 27 bool run(MachineFunction &MF); 28 }; 29 30 struct FEntryInserterLegacy : public MachineFunctionPass { 31 static char ID; // Pass identification, replacement for typeid 32 FEntryInserterLegacy() : MachineFunctionPass(ID) { 33 initializeFEntryInserterLegacyPass(*PassRegistry::getPassRegistry()); 34 } 35 36 bool runOnMachineFunction(MachineFunction &F) override { 37 return FEntryInserter().run(F); 38 } 39 }; 40 } 41 42 PreservedAnalyses FEntryInserterPass::run(MachineFunction &MF, 43 MachineFunctionAnalysisManager &AM) { 44 if (!FEntryInserter().run(MF)) 45 return PreservedAnalyses::all(); 46 return getMachineFunctionPassPreservedAnalyses(); 47 } 48 49 bool FEntryInserter::run(MachineFunction &MF) { 50 const std::string FEntryName = std::string( 51 MF.getFunction().getFnAttribute("fentry-call").getValueAsString()); 52 if (FEntryName != "true") 53 return false; 54 55 auto &FirstMBB = *MF.begin(); 56 auto *TII = MF.getSubtarget().getInstrInfo(); 57 BuildMI(FirstMBB, FirstMBB.begin(), DebugLoc(), 58 TII->get(TargetOpcode::FENTRY_CALL)); 59 return true; 60 } 61 62 char FEntryInserterLegacy::ID = 0; 63 char &llvm::FEntryInserterID = FEntryInserterLegacy::ID; 64 INITIALIZE_PASS(FEntryInserterLegacy, "fentry-insert", "Insert fentry calls", 65 false, false) 66