lib/Analysis/EHPersonalities.cpp

   1 //===- EHPersonalities.cpp - 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 #include "llvm/Analysis/EHPersonalities.h"
  11 #include "llvm/ADT/StringSwitch.h"
  12 #include "llvm/IR/Function.h"
  13 using namespace llvm;
  14
  15 /// See if the given exception handling personality function is one that we
  16 /// understand.  If so, return a description of it; otherwise return Unknown.
  17 EHPersonality llvm::classifyEHPersonality(const Value *Pers) {
  18   const Function *F =
  19       Pers ? dyn_cast<Function>(Pers->stripPointerCasts()) : nullptr;
  20   if (!F)
  21     return EHPersonality::Unknown;
  22   return StringSwitch<EHPersonality>(F->getName())
  23     .Case("__gnat_eh_personality", EHPersonality::GNU_Ada)
  24     .Case("__gxx_personality_v0",  EHPersonality::GNU_CXX)
  25     .Case("__gcc_personality_v0",  EHPersonality::GNU_C)
  26     .Case("__objc_personality_v0", EHPersonality::GNU_ObjC)
  27     .Case("_except_handler3",      EHPersonality::MSVC_X86SEH)
  28     .Case("_except_handler4",      EHPersonality::MSVC_X86SEH)
  29     .Case("__C_specific_handler",  EHPersonality::MSVC_Win64SEH)
  30     .Case("__CxxFrameHandler3",    EHPersonality::MSVC_CXX)
  31     .Case("ProcessCLRException",   EHPersonality::CoreCLR)
  32     .Default(EHPersonality::Unknown);
  33 }
  34
  35 bool llvm::canSimplifyInvokeNoUnwind(const Function *F) {
  36   EHPersonality Personality = classifyEHPersonality(F->getPersonalityFn());
  37   // We can't simplify any invokes to nounwind functions if the personality
  38   // function wants to catch asynch exceptions.  The nounwind attribute only
  39   // implies that the function does not throw synchronous exceptions.
  40   return !isAsynchronousEHPersonality(Personality);
  41 }