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      1 //===-- WinException.h - Windows Exception Handling ----------*- 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 // This file contains support for writing windows exception info into asm files.
     11 //
     12 //===----------------------------------------------------------------------===//
     13 
     14 #ifndef LLVM_LIB_CODEGEN_ASMPRINTER_WIN64EXCEPTION_H
     15 #define LLVM_LIB_CODEGEN_ASMPRINTER_WIN64EXCEPTION_H
     16 
     17 #include "EHStreamer.h"
     18 
     19 namespace llvm {
     20 class Function;
     21 class GlobalValue;
     22 class MachineFunction;
     23 class MCExpr;
     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   /// Pointer to the current funclet entry BB.
     41   const MachineBasicBlock *CurrentFuncletEntry = nullptr;
     42 
     43   void emitCSpecificHandlerTable(const MachineFunction *MF);
     44 
     45   void emitSEHActionsForRange(const WinEHFuncInfo &FuncInfo,
     46                               const MCSymbol *BeginLabel,
     47                               const MCSymbol *EndLabel, int State);
     48 
     49   /// Emit the EH table data for 32-bit and 64-bit functions using
     50   /// the __CxxFrameHandler3 personality.
     51   void emitCXXFrameHandler3Table(const MachineFunction *MF);
     52 
     53   /// Emit the EH table data for _except_handler3 and _except_handler4
     54   /// personality functions. These are only used on 32-bit and do not use CFI
     55   /// tables.
     56   void emitExceptHandlerTable(const MachineFunction *MF);
     57 
     58   void emitCLRExceptionTable(const MachineFunction *MF);
     59 
     60   void computeIP2StateTable(
     61       const MachineFunction *MF, const WinEHFuncInfo &FuncInfo,
     62       SmallVectorImpl<std::pair<const MCExpr *, int>> &IPToStateTable);
     63 
     64   /// Emits the label used with llvm.x86.seh.recoverfp, which is used by
     65   /// outlined funclets.
     66   void emitEHRegistrationOffsetLabel(const WinEHFuncInfo &FuncInfo,
     67                                      StringRef FLinkageName);
     68 
     69   const MCExpr *create32bitRef(const MCSymbol *Value);
     70   const MCExpr *create32bitRef(const GlobalValue *GV);
     71   const MCExpr *getLabelPlusOne(const MCSymbol *Label);
     72   const MCExpr *getOffset(const MCSymbol *OffsetOf, const MCSymbol *OffsetFrom);
     73   const MCExpr *getOffsetPlusOne(const MCSymbol *OffsetOf,
     74                                  const MCSymbol *OffsetFrom);
     75 
     76   /// Gets the offset that we should use in a table for a stack object with the
     77   /// given index. For targets using CFI (Win64, etc), this is relative to the
     78   /// established SP at the end of the prologue. For targets without CFI (Win32
     79   /// only), it is relative to the frame pointer.
     80   int getFrameIndexOffset(int FrameIndex, const WinEHFuncInfo &FuncInfo);
     81 
     82 public:
     83   //===--------------------------------------------------------------------===//
     84   // Main entry points.
     85   //
     86   WinException(AsmPrinter *A);
     87   ~WinException() override;
     88 
     89   /// Emit all exception information that should come after the content.
     90   void endModule() override;
     91 
     92   /// Gather pre-function exception information.  Assumes being emitted
     93   /// immediately after the function entry point.
     94   void beginFunction(const MachineFunction *MF) override;
     95 
     96   /// Gather and emit post-function exception information.
     97   void endFunction(const MachineFunction *) override;
     98 
     99   /// \brief Emit target-specific EH funclet machinery.
    100   void beginFunclet(const MachineBasicBlock &MBB, MCSymbol *Sym) override;
    101   void endFunclet() override;
    102 };
    103 }
    104 
    105 #endif
    106 
    107