1 //===-- WinCFGuard.h - Windows Control Flow Guard Handling ----*- C++ -*--===//
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 contains support for writing the metadata for Windows Control Flow
10 // Guard, including address-taken functions, and valid longjmp targets.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_LIB_CODEGEN_ASMPRINTER_WINCFGUARD_H
15 #define LLVM_LIB_CODEGEN_ASMPRINTER_WINCFGUARD_H
16 
17 #include "llvm/CodeGen/AsmPrinterHandler.h"
18 #include "llvm/Support/Compiler.h"
19 #include <vector>
20 
21 namespace llvm {
22 
23 class LLVM_LIBRARY_VISIBILITY WinCFGuard : public AsmPrinterHandler {
24   /// Target of directive emission.
25   AsmPrinter *Asm;
26   std::vector<const MCSymbol *> LongjmpTargets;
27   MCSymbol *lookupImpSymbol(const MCSymbol *Sym);
28 
29 public:
30   WinCFGuard(AsmPrinter *A);
31   ~WinCFGuard() override;
32 
33   void setSymbolSize(const MCSymbol *Sym, uint64_t Size) override {}
34 
35   /// Emit the Control Flow Guard function ID table.
36   void endModule() override;
37 
38   /// Gather pre-function debug information.
39   /// Every beginFunction(MF) call should be followed by an endFunction(MF)
40   /// call.
41   void beginFunction(const MachineFunction *MF) override {}
42 
43   /// Gather post-function debug information.
44   /// Please note that some AsmPrinter implementations may not call
45   /// beginFunction at all.
46   void endFunction(const MachineFunction *MF) override;
47 
48   /// Process beginning of an instruction.
49   void beginInstruction(const MachineInstr *MI) override {}
50 
51   /// Process end of an instruction.
52   void endInstruction() override {}
53 };
54 
55 } // namespace llvm
56 
57 #endif
58