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 "llvm/ADT/MapVector.h"
14 #include <vector>
15 
16 namespace llvm {
17 class MCSection;
18 class MCStreamer;
19 class MCSymbol;
20 
21 namespace WinEH {
22 struct Instruction {
23   const MCSymbol *Label;
24   unsigned Offset;
25   unsigned Register;
26   unsigned Operation;
27 
InstructionInstruction28   Instruction(unsigned Op, MCSymbol *L, unsigned Reg, unsigned Off)
29     : Label(L), Offset(Off), Register(Reg), Operation(Op) {}
30 };
31 
32 struct FrameInfo {
33   const MCSymbol *Begin = nullptr;
34   const MCSymbol *End = nullptr;
35   const MCSymbol *FuncletOrFuncEnd = nullptr;
36   const MCSymbol *ExceptionHandler = nullptr;
37   const MCSymbol *Function = nullptr;
38   const MCSymbol *PrologEnd = nullptr;
39   const MCSymbol *Symbol = nullptr;
40   const MCSection *TextSection = nullptr;
41 
42   bool HandlesUnwind = false;
43   bool HandlesExceptions = false;
44 
45   int LastFrameInst = -1;
46   const FrameInfo *ChainedParent = nullptr;
47   std::vector<Instruction> Instructions;
48   MapVector<MCSymbol*, std::vector<Instruction>> EpilogMap;
49 
50   FrameInfo() = default;
FrameInfoFrameInfo51   FrameInfo(const MCSymbol *Function, const MCSymbol *BeginFuncEHLabel)
52       : Begin(BeginFuncEHLabel), Function(Function) {}
FrameInfoFrameInfo53   FrameInfo(const MCSymbol *Function, const MCSymbol *BeginFuncEHLabel,
54             const FrameInfo *ChainedParent)
55       : Begin(BeginFuncEHLabel), Function(Function),
56         ChainedParent(ChainedParent) {}
57 };
58 
59 class UnwindEmitter {
60 public:
61   virtual ~UnwindEmitter();
62 
63   /// This emits the unwind info sections (.pdata and .xdata in PE/COFF).
64   virtual void Emit(MCStreamer &Streamer) const = 0;
65   virtual void EmitUnwindInfo(MCStreamer &Streamer, FrameInfo *FI) const = 0;
66 };
67 }
68 }
69 
70 #endif
71