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
FEntryInserterLegacy__anon05c660f80111::FEntryInserterLegacy32 FEntryInserterLegacy() : MachineFunctionPass(ID) {
33 initializeFEntryInserterLegacyPass(*PassRegistry::getPassRegistry());
34 }
35
runOnMachineFunction__anon05c660f80111::FEntryInserterLegacy36 bool runOnMachineFunction(MachineFunction &F) override {
37 return FEntryInserter().run(F);
38 }
39 };
40 }
41
run(MachineFunction & MF,MachineFunctionAnalysisManager & AM)42 PreservedAnalyses FEntryInserterPass::run(MachineFunction &MF,
43 MachineFunctionAnalysisManager &AM) {
44 if (!FEntryInserter().run(MF))
45 return PreservedAnalyses::all();
46 return getMachineFunctionPassPreservedAnalyses();
47 }
48
run(MachineFunction & MF)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