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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/ADT/Triple.h"
     16 #include "llvm/Support/ErrorHandling.h"
     17 
     18 namespace llvm {
     19 class BasicBlock;
     20 class Function;
     21 class Value;
     22 
     23 enum class EHPersonality {
     24   Unknown,
     25   GNU_Ada,
     26   GNU_C,
     27   GNU_C_SjLj,
     28   GNU_CXX,
     29   GNU_CXX_SjLj,
     30   GNU_ObjC,
     31   MSVC_X86SEH,
     32   MSVC_Win64SEH,
     33   MSVC_CXX,
     34   CoreCLR,
     35   Rust
     36 };
     37 
     38 /// \brief See if the given exception handling personality function is one
     39 /// that we understand.  If so, return a description of it; otherwise return
     40 /// Unknown.
     41 EHPersonality classifyEHPersonality(const Value *Pers);
     42 
     43 StringRef getEHPersonalityName(EHPersonality Pers);
     44 
     45 EHPersonality getDefaultEHPersonality(const Triple &T);
     46 
     47 /// \brief Returns true if this personality function catches asynchronous
     48 /// exceptions.
     49 inline bool isAsynchronousEHPersonality(EHPersonality Pers) {
     50   // The two SEH personality functions can catch asynch exceptions. We assume
     51   // unknown personalities don't catch asynch exceptions.
     52   switch (Pers) {
     53   case EHPersonality::MSVC_X86SEH:
     54   case EHPersonality::MSVC_Win64SEH:
     55     return true;
     56   default:
     57     return false;
     58   }
     59   llvm_unreachable("invalid enum");
     60 }
     61 
     62 /// \brief Returns true if this is a personality function that invokes
     63 /// handler funclets (which must return to it).
     64 inline bool isFuncletEHPersonality(EHPersonality Pers) {
     65   switch (Pers) {
     66   case EHPersonality::MSVC_CXX:
     67   case EHPersonality::MSVC_X86SEH:
     68   case EHPersonality::MSVC_Win64SEH:
     69   case EHPersonality::CoreCLR:
     70     return true;
     71   default:
     72     return false;
     73   }
     74   llvm_unreachable("invalid enum");
     75 }
     76 
     77 /// \brief Return true if this personality may be safely removed if there
     78 /// are no invoke instructions remaining in the current function.
     79 inline bool isNoOpWithoutInvoke(EHPersonality Pers) {
     80   switch (Pers) {
     81   case EHPersonality::Unknown:
     82     return false;
     83   // All known personalities currently have this behavior
     84   default:
     85     return true;
     86   }
     87   llvm_unreachable("invalid enum");
     88 }
     89 
     90 bool canSimplifyInvokeNoUnwind(const Function *F);
     91 
     92 typedef TinyPtrVector<BasicBlock *> ColorVector;
     93 
     94 /// \brief If an EH funclet personality is in use (see isFuncletEHPersonality),
     95 /// this will recompute which blocks are in which funclet. It is possible that
     96 /// some blocks are in multiple funclets. Consider this analysis to be
     97 /// expensive.
     98 DenseMap<BasicBlock *, ColorVector> colorEHFunclets(Function &F);
     99 
    100 } // end namespace llvm
    101 
    102 #endif
    103