include/llvm/Analysis/EHPersonalities.h

   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/ADT/Triple.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_C_SjLj,
  27   GNU_CXX,
  28   GNU_CXX_SjLj,
  29   GNU_ObjC,
  30   MSVC_X86SEH,
  31   MSVC_Win64SEH,
  32   MSVC_CXX,
  33   CoreCLR,
  34   Rust,
  35   Wasm_CXX
  36 };
  37
  38 /// 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 /// 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 /// 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 /// Returns true if this personality uses scope-style EH IR instructions:
  78 /// catchswitch, catchpad/ret, and cleanuppad/ret.
  79 inline bool isScopedEHPersonality(EHPersonality Pers) {
  80   switch (Pers) {
  81   case EHPersonality::MSVC_CXX:
  82   case EHPersonality::MSVC_X86SEH:
  83   case EHPersonality::MSVC_Win64SEH:
  84   case EHPersonality::CoreCLR:
  85   case EHPersonality::Wasm_CXX:
  86     return true;
  87   default:
  88     return false;
  89   }
  90   llvm_unreachable("invalid enum");
  91 }
  92
  93 /// Return true if this personality may be safely removed if there
  94 /// are no invoke instructions remaining in the current function.
  95 inline bool isNoOpWithoutInvoke(EHPersonality Pers) {
  96   switch (Pers) {
  97   case EHPersonality::Unknown:
  98     return false;
  99   // All known personalities currently have this behavior
 100   default:
 101     return true;
 102   }
 103   llvm_unreachable("invalid enum");
 104 }
 105
 106 bool canSimplifyInvokeNoUnwind(const Function *F);
 107
 108 typedef TinyPtrVector<BasicBlock *> ColorVector;
 109
 110 /// If an EH funclet personality is in use (see isFuncletEHPersonality),
 111 /// this will recompute which blocks are in which funclet. It is possible that
 112 /// some blocks are in multiple funclets. Consider this analysis to be
 113 /// expensive.
 114 DenseMap<BasicBlock *, ColorVector> colorEHFunclets(Function &F);
 115
 116 } // end namespace llvm
 117
 118 #endif