WinCFGuard.h

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//===-- WinCFGuard.h - Windows Control Flow Guard Handling ----*- C++ -*--===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// This file contains support for writing the metadata for Windows Control Flow
// Guard, including address-taken functions, and valid longjmp targets.
//
//===----------------------------------------------------------------------===//
 
#ifndef LLVM_LIB_CODEGEN_ASMPRINTER_WINCFGUARD_H
#define LLVM_LIB_CODEGEN_ASMPRINTER_WINCFGUARD_H
 
#include "llvm/CodeGen/AsmPrinterHandler.h"
#include "llvm/Support/Compiler.h"
#include <vector>
 
namespace llvm {
 
class LLVM_LIBRARY_VISIBILITY WinCFGuard : public AsmPrinterHandler {
  /// Target of directive emission.
  AsmPrinter *Asm;
  std::vector<const MCSymbol *> LongjmpTargets;
  MCSymbol *lookupImpSymbol(const MCSymbol *Sym);
 
public:
  WinCFGuard(AsmPrinter *A);
  ~WinCFGuard() override;
 
  void setSymbolSize(const MCSymbol *Sym, uint64_t Size) override {}
 
  /// Emit the Control Flow Guard function ID table.
  void endModule() override;
 
  /// Gather pre-function debug information.
  /// Every beginFunction(MF) call should be followed by an endFunction(MF)
  /// call.
  void beginFunction(const MachineFunction *MF) override {}
 
  /// Gather post-function debug information.
  /// Please note that some AsmPrinter implementations may not call
  /// beginFunction at all.
  void endFunction(const MachineFunction *MF) override;
 
  /// Process beginning of an instruction.
  void beginInstruction(const MachineInstr *MI) override {}
 
  /// Process end of an instruction.
  void endInstruction() override {}
};
 
} // namespace llvm
 
#endif