lib/CodeGen/FEntryInserter.cpp

   1 //===-- FEntryInsertion.cpp - Patchable prologues for LLVM -------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This file edits function bodies to insert fentry calls.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "llvm/CodeGen/MachineFunction.h"
  15 #include "llvm/CodeGen/MachineFunctionPass.h"
  16 #include "llvm/CodeGen/MachineInstrBuilder.h"
  17 #include "llvm/CodeGen/Passes.h"
  18 #include "llvm/CodeGen/TargetFrameLowering.h"
  19 #include "llvm/CodeGen/TargetInstrInfo.h"
  20 #include "llvm/CodeGen/TargetSubtargetInfo.h"
  21 #include "llvm/IR/Function.h"
  22 #include "llvm/IR/Module.h"
  23
  24 using namespace llvm;
  25
  26 namespace {
  27 struct FEntryInserter : public MachineFunctionPass {
  28   static char ID; // Pass identification, replacement for typeid
  29   FEntryInserter() : MachineFunctionPass(ID) {
  30     initializeFEntryInserterPass(*PassRegistry::getPassRegistry());
  31   }
  32
  33   bool runOnMachineFunction(MachineFunction &F) override;
  34 };
  35 }
  36
  37 bool FEntryInserter::runOnMachineFunction(MachineFunction &MF) {
  38   const std::string FEntryName =
  39       MF.getFunction().getFnAttribute("fentry-call").getValueAsString();
  40   if (FEntryName != "true")
  41     return false;
  42
  43   auto &FirstMBB = *MF.begin();
  44   auto *TII = MF.getSubtarget().getInstrInfo();
  45   BuildMI(FirstMBB, FirstMBB.begin(), DebugLoc(),
  46           TII->get(TargetOpcode::FENTRY_CALL));
  47   return true;
  48 }
  49
  50 char FEntryInserter::ID = 0;
  51 char &llvm::FEntryInserterID = FEntryInserter::ID;
  52 INITIALIZE_PASS(FEntryInserter, "fentry-insert", "Insert fentry calls", false,
  53                 false)