//===-- EHContGuardCatchret.cpp - Catchret target symbols -------*- 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 // //===----------------------------------------------------------------------===// /// /// \file /// This file contains a machine function pass to insert a symbol before each /// valid catchret target and store this in the MachineFunction's /// CatchRetTargets vector. This will be used to emit the table of valid targets /// used by EHCont Guard. /// //===----------------------------------------------------------------------===// #include "llvm/ADT/Statistic.h" #include "llvm/CodeGen/MachineBasicBlock.h" #include "llvm/CodeGen/MachineFunctionPass.h" #include "llvm/CodeGen/MachineModuleInfo.h" #include "llvm/CodeGen/Passes.h" #include "llvm/IR/Module.h" #include "llvm/InitializePasses.h" using namespace llvm; #define DEBUG_TYPE "ehcontguard-catchret" STATISTIC(EHContGuardCatchretTargets, "Number of EHCont Guard catchret targets"); namespace { /// MachineFunction pass to insert a symbol before each valid catchret target /// and store these in the MachineFunction's CatchRetTargets vector. class EHContGuardCatchret : public MachineFunctionPass { public: static char ID; EHContGuardCatchret() : MachineFunctionPass(ID) { initializeEHContGuardCatchretPass(*PassRegistry::getPassRegistry()); } StringRef getPassName() const override { return "EH Cont Guard catchret targets"; } bool runOnMachineFunction(MachineFunction &MF) override; }; } // end anonymous namespace char EHContGuardCatchret::ID = 0; INITIALIZE_PASS(EHContGuardCatchret, "EHContGuardCatchret", "Insert symbols at valid catchret targets for /guard:ehcont", false, false) FunctionPass *llvm::createEHContGuardCatchretPass() { return new EHContGuardCatchret(); } bool EHContGuardCatchret::runOnMachineFunction(MachineFunction &MF) { // Skip modules for which the ehcontguard flag is not set. if (!MF.getFunction().getParent()->getModuleFlag("ehcontguard")) return false; // Skip functions that do not have catchret if (!MF.hasEHCatchret()) return false; bool Result = false; for (MachineBasicBlock &MBB : MF) { if (MBB.isEHCatchretTarget()) { MF.addCatchretTarget(MBB.getEHCatchretSymbol()); EHContGuardCatchretTargets++; Result = true; } } return Result; }