xref: /freebsd/contrib/llvm-project/llvm/lib/CodeGen/FEntryInserter.cpp (revision 6966ac055c3b7a39266fb982493330df7a097997)
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/Passes.h"
17 #include "llvm/CodeGen/TargetFrameLowering.h"
18 #include "llvm/CodeGen/TargetInstrInfo.h"
19 #include "llvm/CodeGen/TargetSubtargetInfo.h"
20 #include "llvm/IR/Function.h"
21 #include "llvm/IR/Module.h"
22 
23 using namespace llvm;
24 
25 namespace {
26 struct FEntryInserter : public MachineFunctionPass {
27   static char ID; // Pass identification, replacement for typeid
28   FEntryInserter() : MachineFunctionPass(ID) {
29     initializeFEntryInserterPass(*PassRegistry::getPassRegistry());
30   }
31 
32   bool runOnMachineFunction(MachineFunction &F) override;
33 };
34 }
35 
36 bool FEntryInserter::runOnMachineFunction(MachineFunction &MF) {
37   const std::string FEntryName =
38       MF.getFunction().getFnAttribute("fentry-call").getValueAsString();
39   if (FEntryName != "true")
40     return false;
41 
42   auto &FirstMBB = *MF.begin();
43   auto *TII = MF.getSubtarget().getInstrInfo();
44   BuildMI(FirstMBB, FirstMBB.begin(), DebugLoc(),
45           TII->get(TargetOpcode::FENTRY_CALL));
46   return true;
47 }
48 
49 char FEntryInserter::ID = 0;
50 char &llvm::FEntryInserterID = FEntryInserter::ID;
51 INITIALIZE_PASS(FEntryInserter, "fentry-insert", "Insert fentry calls", false,
52                 false)
53