lib/CodeGen/AsmPrinter/WinException.h

   1 //===-- WinException.h - Windows Exception 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 windows exception info into asm files.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #ifndef LLVM_LIB_CODEGEN_ASMPRINTER_WIN64EXCEPTION_H
  14 #define LLVM_LIB_CODEGEN_ASMPRINTER_WIN64EXCEPTION_H
  15
  16 #include "EHStreamer.h"
  17
  18 namespace llvm {
  19 class Function;
  20 class GlobalValue;
  21 class MachineFunction;
  22 class MCExpr;
  23 class MCSection;
  24 class Value;
  25 struct WinEHFuncInfo;
  26
  27 class LLVM_LIBRARY_VISIBILITY WinException : public EHStreamer {
  28   /// Per-function flag to indicate if personality info should be emitted.
  29   bool shouldEmitPersonality = false;
  30
  31   /// Per-function flag to indicate if the LSDA should be emitted.
  32   bool shouldEmitLSDA = false;
  33
  34   /// Per-function flag to indicate if frame moves info should be emitted.
  35   bool shouldEmitMoves = false;
  36
  37   /// True if this is a 64-bit target and we should use image relative offsets.
  38   bool useImageRel32 = false;
  39
  40   /// True if we are generating exception handling on Windows for ARM64.
  41   bool isAArch64 = false;
  42
  43   /// Pointer to the current funclet entry BB.
  44   const MachineBasicBlock *CurrentFuncletEntry = nullptr;
  45
  46   /// The section of the last funclet start.
  47   MCSection *CurrentFuncletTextSection = nullptr;
  48
  49   void emitCSpecificHandlerTable(const MachineFunction *MF);
  50
  51   void emitSEHActionsForRange(const WinEHFuncInfo &FuncInfo,
  52                               const MCSymbol *BeginLabel,
  53                               const MCSymbol *EndLabel, int State);
  54
  55   /// Emit the EH table data for 32-bit and 64-bit functions using
  56   /// the __CxxFrameHandler3 personality.
  57   void emitCXXFrameHandler3Table(const MachineFunction *MF);
  58
  59   /// Emit the EH table data for _except_handler3 and _except_handler4
  60   /// personality functions. These are only used on 32-bit and do not use CFI
  61   /// tables.
  62   void emitExceptHandlerTable(const MachineFunction *MF);
  63
  64   void emitCLRExceptionTable(const MachineFunction *MF);
  65
  66   void computeIP2StateTable(
  67       const MachineFunction *MF, const WinEHFuncInfo &FuncInfo,
  68       SmallVectorImpl<std::pair<const MCExpr *, int>> &IPToStateTable);
  69
  70   /// Emits the label used with llvm.eh.recoverfp, which is used by
  71   /// outlined funclets.
  72   void emitEHRegistrationOffsetLabel(const WinEHFuncInfo &FuncInfo,
  73                                      StringRef FLinkageName);
  74
  75   const MCExpr *create32bitRef(const MCSymbol *Value);
  76   const MCExpr *create32bitRef(const GlobalValue *GV);
  77   const MCExpr *getLabel(const MCSymbol *Label);
  78   const MCExpr *getOffset(const MCSymbol *OffsetOf, const MCSymbol *OffsetFrom);
  79   const MCExpr *getOffsetPlusOne(const MCSymbol *OffsetOf,
  80                                  const MCSymbol *OffsetFrom);
  81
  82   /// Gets the offset that we should use in a table for a stack object with the
  83   /// given index. For targets using CFI (Win64, etc), this is relative to the
  84   /// established SP at the end of the prologue. For targets without CFI (Win32
  85   /// only), it is relative to the frame pointer.
  86   int getFrameIndexOffset(int FrameIndex, const WinEHFuncInfo &FuncInfo);
  87
  88   void endFuncletImpl();
  89 public:
  90   //===--------------------------------------------------------------------===//
  91   // Main entry points.
  92   //
  93   WinException(AsmPrinter *A);
  94   ~WinException() override;
  95
  96   /// Emit all exception information that should come after the content.
  97   void endModule() override;
  98
  99   /// Gather pre-function exception information.  Assumes being emitted
 100   /// immediately after the function entry point.
 101   void beginFunction(const MachineFunction *MF) override;
 102
 103   void markFunctionEnd() override;
 104
 105   /// Gather and emit post-function exception information.
 106   void endFunction(const MachineFunction *) override;
 107
 108   /// Emit target-specific EH funclet machinery.
 109   void beginFunclet(const MachineBasicBlock &MBB, MCSymbol *Sym) override;
 110   void endFunclet() override;
 111 };
 112 }
 113
 114 #endif
 115