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      1 //===- EHPersonalities.h - Compute EH-related information -----------------===//
      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_ANALYSIS_EHPERSONALITIES_H
     11 #define LLVM_ANALYSIS_EHPERSONALITIES_H
     12 
     13 #include "llvm/ADT/DenseMap.h"
     14 #include "llvm/ADT/TinyPtrVector.h"
     15 #include "llvm/Support/ErrorHandling.h"
     16 
     17 namespace llvm {
     18 class BasicBlock;
     19 class Function;
     20 class Value;
     21 
     22 enum class EHPersonality {
     23   Unknown,
     24   GNU_Ada,
     25   GNU_C,
     26   GNU_CXX,
     27   GNU_ObjC,
     28   MSVC_X86SEH,
     29   MSVC_Win64SEH,
     30   MSVC_CXX,
     31   CoreCLR
     32 };
     33 
     34 /// \brief See if the given exception handling personality function is one
     35 /// that we understand.  If so, return a description of it; otherwise return
     36 /// Unknown.
     37 EHPersonality classifyEHPersonality(const Value *Pers);
     38 
     39 /// \brief Returns true if this personality function catches asynchronous
     40 /// exceptions.
     41 inline bool isAsynchronousEHPersonality(EHPersonality Pers) {
     42   // The two SEH personality functions can catch asynch exceptions. We assume
     43   // unknown personalities don't catch asynch exceptions.
     44   switch (Pers) {
     45   case EHPersonality::MSVC_X86SEH:
     46   case EHPersonality::MSVC_Win64SEH:
     47     return true;
     48   default:
     49     return false;
     50   }
     51   llvm_unreachable("invalid enum");
     52 }
     53 
     54 /// \brief Returns true if this is a personality function that invokes
     55 /// handler funclets (which must return to it).
     56 inline bool isFuncletEHPersonality(EHPersonality Pers) {
     57   switch (Pers) {
     58   case EHPersonality::MSVC_CXX:
     59   case EHPersonality::MSVC_X86SEH:
     60   case EHPersonality::MSVC_Win64SEH:
     61   case EHPersonality::CoreCLR:
     62     return true;
     63   default:
     64     return false;
     65   }
     66   llvm_unreachable("invalid enum");
     67 }
     68 
     69 /// \brief Return true if this personality may be safely removed if there
     70 /// are no invoke instructions remaining in the current function.
     71 inline bool isNoOpWithoutInvoke(EHPersonality Pers) {
     72   switch (Pers) {
     73   case EHPersonality::Unknown:
     74     return false;
     75   // All known personalities currently have this behavior
     76   default:
     77     return true;
     78   }
     79   llvm_unreachable("invalid enum");
     80 }
     81 
     82 bool canSimplifyInvokeNoUnwind(const Function *F);
     83 
     84 typedef TinyPtrVector<BasicBlock *> ColorVector;
     85 
     86 /// \brief If an EH funclet personality is in use (see isFuncletEHPersonality),
     87 /// this will recompute which blocks are in which funclet. It is possible that
     88 /// some blocks are in multiple funclets. Consider this analysis to be
     89 /// expensive.
     90 DenseMap<BasicBlock *, ColorVector> colorEHFunclets(Function &F);
     91 
     92 } // end namespace llvm
     93 
     94 #endif
     95