llvm/lib/CodeGen/FEntryInserter.cpp
Nirav Dave 53d52e9e2b [X86] Implement -mfentry
Summary: Insert calls to __fentry__ at function entry.

Reviewers: hfinkel, craig.topper

Subscribers: mgorny, llvm-commits

Differential Revision: https://reviews.llvm.org/D28000

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@293648 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-31 17:00:27 +00:00

56 lines
1.8 KiB
C++

//===-- FEntryInsertion.cpp - Patchable prologues for LLVM -------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file edits function bodies to insert fentry calls.
//
//===----------------------------------------------------------------------===//
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/Module.h"
#include "llvm/Target/TargetFrameLowering.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Target/TargetSubtargetInfo.h"
using namespace llvm;
namespace {
struct FEntryInserter : public MachineFunctionPass {
static char ID; // Pass identification, replacement for typeid
FEntryInserter() : MachineFunctionPass(ID) {
initializeFEntryInserterPass(*PassRegistry::getPassRegistry());
}
bool runOnMachineFunction(MachineFunction &F) override;
};
}
bool FEntryInserter::runOnMachineFunction(MachineFunction &MF) {
const std::string FEntryName =
MF.getFunction()->getFnAttribute("fentry-call").getValueAsString();
if (FEntryName != "true")
return false;
auto &FirstMBB = *MF.begin();
auto &FirstMI = *FirstMBB.begin();
auto *TII = MF.getSubtarget().getInstrInfo();
BuildMI(FirstMBB, FirstMI, FirstMI.getDebugLoc(),
TII->get(TargetOpcode::FENTRY_CALL));
return true;
}
char FEntryInserter::ID = 0;
char &llvm::FEntryInserterID = FEntryInserter::ID;
INITIALIZE_PASS(FEntryInserter, "fentry-insert", "Insert fentry calls", false,
false)