llvm/llvm/lib/CodeGen/CFIInstrInserter.cpp

//===------ CFIInstrInserter.cpp - Insert additional CFI instructions -----===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
/// \file This pass verifies incoming and outgoing CFA information of basic
/// blocks. CFA information is information about offset and register set by CFI
/// directives, valid at the start and end of a basic block. This pass checks
/// that outgoing information of predecessors matches incoming information of
/// their successors. Then it checks if blocks have correct CFA calculation rule
/// set and inserts additional CFI instruction at their beginnings if they
/// don't. CFI instructions are inserted if basic blocks have incorrect offset
/// or register set by previous blocks, as a result of a non-linear layout of
/// blocks in a function.
//===----------------------------------------------------------------------===//

#include "llvm/ADT/DepthFirstIterator.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/CodeGen/TargetFrameLowering.h"
#include "llvm/CodeGen/TargetInstrInfo.h"
#include "llvm/CodeGen/TargetSubtargetInfo.h"
#include "llvm/InitializePasses.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCDwarf.h"
usingnamespacellvm;

static cl::opt<bool> VerifyCFI("verify-cfiinstrs",
    cl::desc("Verify Call Frame Information instructions"),
    cl::init(false),
    cl::Hidden);

namespace {
class CFIInstrInserter : public MachineFunctionPass { … };
}  // namespace

char CFIInstrInserter::ID = …;
INITIALIZE_PASS(…)
FunctionPass *llvm::createCFIInstrInserter() { … }

void CFIInstrInserter::calculateCFAInfo(MachineFunction &MF) { … }

void CFIInstrInserter::calculateOutgoingCFAInfo(MBBCFAInfo &MBBInfo) { … }

void CFIInstrInserter::updateSuccCFAInfo(MBBCFAInfo &MBBInfo) { … }

bool CFIInstrInserter::insertCFIInstrs(MachineFunction &MF) { … }

void CFIInstrInserter::reportCFAError(const MBBCFAInfo &Pred,
                                      const MBBCFAInfo &Succ) { … }

void CFIInstrInserter::reportCSRError(const MBBCFAInfo &Pred,
                                      const MBBCFAInfo &Succ) { … }

unsigned CFIInstrInserter::verify(MachineFunction &MF) { … }