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      1 //===- EHPersonalities.h - Compute EH-related information -----------------===//
      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 #ifndef LLVM_ANALYSIS_EHPERSONALITIES_H
     10 #define LLVM_ANALYSIS_EHPERSONALITIES_H
     11 
     12 #include "llvm/ADT/DenseMap.h"
     13 #include "llvm/ADT/TinyPtrVector.h"
     14 #include "llvm/Support/ErrorHandling.h"
     15 
     16 namespace llvm {
     17 class BasicBlock;
     18 class Function;
     19 class Triple;
     20 class Value;
     21 
     22 enum class EHPersonality {
     23   Unknown,
     24   GNU_Ada,
     25   GNU_C,
     26   GNU_C_SjLj,
     27   GNU_CXX,
     28   GNU_CXX_SjLj,
     29   GNU_ObjC,
     30   MSVC_X86SEH,
     31   MSVC_TableSEH,
     32   MSVC_CXX,
     33   CoreCLR,
     34   Rust,
     35   Wasm_CXX,
     36   XL_CXX
     37 };
     38 
     39 /// See if the given exception handling personality function is one
     40 /// that we understand.  If so, return a description of it; otherwise return
     41 /// Unknown.
     42 EHPersonality classifyEHPersonality(const Value *Pers);
     43 
     44 StringRef getEHPersonalityName(EHPersonality Pers);
     45 
     46 EHPersonality getDefaultEHPersonality(const Triple &T);
     47 
     48 /// Returns true if this personality function catches asynchronous
     49 /// exceptions.
     50 inline bool isAsynchronousEHPersonality(EHPersonality Pers) {
     51   // The two SEH personality functions can catch asynch exceptions. We assume
     52   // unknown personalities don't catch asynch exceptions.
     53   switch (Pers) {
     54   case EHPersonality::MSVC_X86SEH:
     55   case EHPersonality::MSVC_TableSEH:
     56     return true;
     57   default:
     58     return false;
     59   }
     60   llvm_unreachable("invalid enum");
     61 }
     62 
     63 /// Returns true if this is a personality function that invokes
     64 /// handler funclets (which must return to it).
     65 inline bool isFuncletEHPersonality(EHPersonality Pers) {
     66   switch (Pers) {
     67   case EHPersonality::MSVC_CXX:
     68   case EHPersonality::MSVC_X86SEH:
     69   case EHPersonality::MSVC_TableSEH:
     70   case EHPersonality::CoreCLR:
     71     return true;
     72   default:
     73     return false;
     74   }
     75   llvm_unreachable("invalid enum");
     76 }
     77 
     78 /// Returns true if this personality uses scope-style EH IR instructions:
     79 /// catchswitch, catchpad/ret, and cleanuppad/ret.
     80 inline bool isScopedEHPersonality(EHPersonality Pers) {
     81   switch (Pers) {
     82   case EHPersonality::MSVC_CXX:
     83   case EHPersonality::MSVC_X86SEH:
     84   case EHPersonality::MSVC_TableSEH:
     85   case EHPersonality::CoreCLR:
     86   case EHPersonality::Wasm_CXX:
     87     return true;
     88   default:
     89     return false;
     90   }
     91   llvm_unreachable("invalid enum");
     92 }
     93 
     94 /// Return true if this personality may be safely removed if there
     95 /// are no invoke instructions remaining in the current function.
     96 inline bool isNoOpWithoutInvoke(EHPersonality Pers) {
     97   switch (Pers) {
     98   case EHPersonality::Unknown:
     99     return false;
    100   // All known personalities currently have this behavior
    101   default:
    102     return true;
    103   }
    104   llvm_unreachable("invalid enum");
    105 }
    106 
    107 bool canSimplifyInvokeNoUnwind(const Function *F);
    108 
    109 typedef TinyPtrVector<BasicBlock *> ColorVector;
    110 
    111 /// If an EH funclet personality is in use (see isFuncletEHPersonality),
    112 /// this will recompute which blocks are in which funclet. It is possible that
    113 /// some blocks are in multiple funclets. Consider this analysis to be
    114 /// expensive.
    115 DenseMap<BasicBlock *, ColorVector> colorEHFunclets(Function &F);
    116 
    117 } // end namespace llvm
    118 
    119 #endif
    120