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      1 //===-- llvm/CodeGen/WinEHFuncInfo.h ----------------------------*- 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 // Data structures and associated state for Windows exception handling schemes.
     11 //
     12 //===----------------------------------------------------------------------===//
     13 
     14 #ifndef LLVM_CODEGEN_WINEHFUNCINFO_H
     15 #define LLVM_CODEGEN_WINEHFUNCINFO_H
     16 
     17 #include "llvm/ADT/DenseMap.h"
     18 #include "llvm/ADT/PointerUnion.h"
     19 #include "llvm/ADT/SmallVector.h"
     20 #include "llvm/ADT/TinyPtrVector.h"
     21 
     22 namespace llvm {
     23 class AllocaInst;
     24 class BasicBlock;
     25 class CatchReturnInst;
     26 class Constant;
     27 class Function;
     28 class GlobalVariable;
     29 class InvokeInst;
     30 class IntrinsicInst;
     31 class LandingPadInst;
     32 class MCExpr;
     33 class MCSymbol;
     34 class MachineBasicBlock;
     35 class Value;
     36 
     37 // The following structs respresent the .xdata tables for various
     38 // Windows-related EH personalities.
     39 
     40 typedef PointerUnion<const BasicBlock *, MachineBasicBlock *> MBBOrBasicBlock;
     41 
     42 struct CxxUnwindMapEntry {
     43   int ToState;
     44   MBBOrBasicBlock Cleanup;
     45 };
     46 
     47 /// Similar to CxxUnwindMapEntry, but supports SEH filters.
     48 struct SEHUnwindMapEntry {
     49   /// If unwinding continues through this handler, transition to the handler at
     50   /// this state. This indexes into SEHUnwindMap.
     51   int ToState = -1;
     52 
     53   bool IsFinally = false;
     54 
     55   /// Holds the filter expression function.
     56   const Function *Filter = nullptr;
     57 
     58   /// Holds the __except or __finally basic block.
     59   MBBOrBasicBlock Handler;
     60 };
     61 
     62 struct WinEHHandlerType {
     63   int Adjectives;
     64   /// The CatchObj starts out life as an LLVM alloca and is eventually turned
     65   /// frame index.
     66   union {
     67     const AllocaInst *Alloca;
     68     int FrameIndex;
     69   } CatchObj = {};
     70   GlobalVariable *TypeDescriptor;
     71   MBBOrBasicBlock Handler;
     72 };
     73 
     74 struct WinEHTryBlockMapEntry {
     75   int TryLow = -1;
     76   int TryHigh = -1;
     77   int CatchHigh = -1;
     78   SmallVector<WinEHHandlerType, 1> HandlerArray;
     79 };
     80 
     81 enum class ClrHandlerType { Catch, Finally, Fault, Filter };
     82 
     83 struct ClrEHUnwindMapEntry {
     84   MBBOrBasicBlock Handler;
     85   uint32_t TypeToken;
     86   int Parent;
     87   ClrHandlerType HandlerType;
     88 };
     89 
     90 struct WinEHFuncInfo {
     91   DenseMap<const Instruction *, int> EHPadStateMap;
     92   DenseMap<const FuncletPadInst *, int> FuncletBaseStateMap;
     93   DenseMap<const InvokeInst *, int> InvokeStateMap;
     94   DenseMap<const CatchReturnInst *, const BasicBlock *>
     95       CatchRetSuccessorColorMap;
     96   DenseMap<MCSymbol *, std::pair<int, MCSymbol *>> LabelToStateMap;
     97   SmallVector<CxxUnwindMapEntry, 4> CxxUnwindMap;
     98   SmallVector<WinEHTryBlockMapEntry, 4> TryBlockMap;
     99   SmallVector<SEHUnwindMapEntry, 4> SEHUnwindMap;
    100   SmallVector<ClrEHUnwindMapEntry, 4> ClrEHUnwindMap;
    101   int UnwindHelpFrameIdx = INT_MAX;
    102   int PSPSymFrameIdx = INT_MAX;
    103 
    104   int getLastStateNumber() const { return CxxUnwindMap.size() - 1; }
    105 
    106   void addIPToStateRange(const InvokeInst *II, MCSymbol *InvokeBegin,
    107                          MCSymbol *InvokeEnd);
    108 
    109   int EHRegNodeFrameIndex = INT_MAX;
    110   int EHRegNodeEndOffset = INT_MAX;
    111   int SEHSetFrameOffset = INT_MAX;
    112 
    113   WinEHFuncInfo() {}
    114 };
    115 
    116 /// Analyze the IR in ParentFn and it's handlers to build WinEHFuncInfo, which
    117 /// describes the state numbers and tables used by __CxxFrameHandler3. This
    118 /// analysis assumes that WinEHPrepare has already been run.
    119 void calculateWinCXXEHStateNumbers(const Function *ParentFn,
    120                                    WinEHFuncInfo &FuncInfo);
    121 
    122 void calculateSEHStateNumbers(const Function *ParentFn,
    123                               WinEHFuncInfo &FuncInfo);
    124 
    125 void calculateClrEHStateNumbers(const Function *Fn, WinEHFuncInfo &FuncInfo);
    126 
    127 void calculateCatchReturnSuccessorColors(const Function *Fn,
    128                                          WinEHFuncInfo &FuncInfo);
    129 }
    130 #endif // LLVM_CODEGEN_WINEHFUNCINFO_H
    131