include/llvm/MC/MCWinEH.h

   1 //===- MCWinEH.h - Windows Unwinding Support --------------------*- 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 #ifndef LLVM_MC_MCWINEH_H
  10 #define LLVM_MC_MCWINEH_H
  11
  12 #include "llvm/ADT/MapVector.h"
  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   unsigned Offset;
  24   unsigned Register;
  25   unsigned Operation;
  26
  27   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 *FuncletOrFuncEnd = nullptr;
  35   const MCSymbol *ExceptionHandler = nullptr;
  36   const MCSymbol *Function = nullptr;
  37   const MCSymbol *PrologEnd = nullptr;
  38   const MCSymbol *Symbol = nullptr;
  39   const MCSection *TextSection = nullptr;
  40
  41   bool HandlesUnwind = false;
  42   bool HandlesExceptions = false;
  43
  44   int LastFrameInst = -1;
  45   const FrameInfo *ChainedParent = nullptr;
  46   std::vector<Instruction> Instructions;
  47   MapVector<MCSymbol*, std::vector<Instruction>> EpilogMap;
  48
  49   FrameInfo() = default;
  50   FrameInfo(const MCSymbol *Function, const MCSymbol *BeginFuncEHLabel)
  51       : Begin(BeginFuncEHLabel), Function(Function) {}
  52   FrameInfo(const MCSymbol *Function, const MCSymbol *BeginFuncEHLabel,
  53             const FrameInfo *ChainedParent)
  54       : Begin(BeginFuncEHLabel), Function(Function),
  55         ChainedParent(ChainedParent) {}
  56 };
  57
  58 class UnwindEmitter {
  59 public:
  60   virtual ~UnwindEmitter();
  61
  62   /// This emits the unwind info sections (.pdata and .xdata in PE/COFF).
  63   virtual void Emit(MCStreamer &Streamer) const = 0;
  64   virtual void EmitUnwindInfo(MCStreamer &Streamer, FrameInfo *FI) const = 0;
  65 };
  66 }
  67 }
  68
  69 #endif