1 //===- MCWinEH.h - Windows Unwinding Support --------------------*- C++ -*-===//
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 #ifndef LLVM_MC_MCWINEH_H
11 #define LLVM_MC_MCWINEH_H
12 
13 #include <vector>
14 
15 namespace llvm {
16 class MCSection;
17 class MCStreamer;
18 class MCSymbol;
19 
20 namespace WinEH {
21 struct Instruction {
22   const MCSymbol *Label;
23   const unsigned Offset;
24   const unsigned Register;
25   const unsigned Operation;
26 
InstructionInstruction27   Instruction(unsigned Op, MCSymbol *L, unsigned Reg, unsigned Off)
28     : Label(L), Offset(Off), Register(Reg), Operation(Op) {}
29 };
30 
31 struct FrameInfo {
32   const MCSymbol *Begin = nullptr;
33   const MCSymbol *End = nullptr;
34   const MCSymbol *ExceptionHandler = nullptr;
35   const MCSymbol *Function = nullptr;
36   const MCSymbol *PrologEnd = nullptr;
37   const MCSymbol *Symbol = nullptr;
38   const MCSection *TextSection = nullptr;
39 
40   bool HandlesUnwind = false;
41   bool HandlesExceptions = false;
42 
43   int LastFrameInst = -1;
44   const FrameInfo *ChainedParent = nullptr;
45   std::vector<Instruction> Instructions;
46 
47   FrameInfo() = default;
FrameInfoFrameInfo48   FrameInfo(const MCSymbol *Function, const MCSymbol *BeginFuncEHLabel)
49       : Begin(BeginFuncEHLabel), Function(Function) {}
FrameInfoFrameInfo50   FrameInfo(const MCSymbol *Function, const MCSymbol *BeginFuncEHLabel,
51             const FrameInfo *ChainedParent)
52       : Begin(BeginFuncEHLabel), Function(Function),
53         ChainedParent(ChainedParent) {}
54 };
55 
56 class UnwindEmitter {
57 public:
58   virtual ~UnwindEmitter();
59 
60   /// This emits the unwind info sections (.pdata and .xdata in PE/COFF).
61   virtual void Emit(MCStreamer &Streamer) const = 0;
62   virtual void EmitUnwindInfo(MCStreamer &Streamer, FrameInfo *FI) const = 0;
63 };
64 }
65 }
66 
67 #endif
68