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/MachineFunction.h"
14#include "llvm/CodeGen/MachineFunctionPass.h"
15#include "llvm/CodeGen/MachineInstrBuilder.h"
16#include "llvm/CodeGen/TargetInstrInfo.h"
17#include "llvm/CodeGen/TargetSubtargetInfo.h"
18#include "llvm/IR/Function.h"
19#include "llvm/InitializePasses.h"
20
21using namespace llvm;
22
23namespace {
24struct FEntryInserter : public MachineFunctionPass {
25 static char ID; // Pass identification, replacement for typeid
26 FEntryInserter() : MachineFunctionPass(ID) {
27 initializeFEntryInserterPass(*PassRegistry::getPassRegistry());
28 }
29
30 bool runOnMachineFunction(MachineFunction &F) override;
31};
32}
33
34bool FEntryInserter::runOnMachineFunction(MachineFunction &MF) {
35 const std::string FEntryName = std::string(
36 MF.getFunction().getFnAttribute(Kind: "fentry-call").getValueAsString());
37 if (FEntryName != "true")
38 return false;
39
40 auto &FirstMBB = *MF.begin();
41 auto *TII = MF.getSubtarget().getInstrInfo();
42 BuildMI(BB&: FirstMBB, I: FirstMBB.begin(), MIMD: DebugLoc(),
43 MCID: TII->get(Opcode: TargetOpcode::FENTRY_CALL));
44 return true;
45}
46
47char FEntryInserter::ID = 0;
48char &llvm::FEntryInserterID = FEntryInserter::ID;
49INITIALIZE_PASS(FEntryInserter, "fentry-insert", "Insert fentry calls", false,
50 false)
51