EHPersonalities.cpp revision 292915
1169691Skan//===- EHPersonalities.cpp - Compute EH-related information ---------------===// 2169691Skan// 3169691Skan// The LLVM Compiler Infrastructure 4169691Skan// 5169691Skan// This file is distributed under the University of Illinois Open Source 6169691Skan// License. See LICENSE.TXT for details. 7169691Skan// 8169691Skan//===----------------------------------------------------------------------===// 9169691Skan 10169691Skan#include "llvm/Analysis/EHPersonalities.h" 11169691Skan#include "llvm/ADT/StringSwitch.h" 12169691Skan#include "llvm/IR/CFG.h" 13169691Skan#include "llvm/IR/Constants.h" 14169691Skan#include "llvm/IR/Function.h" 15169691Skan#include "llvm/IR/Instructions.h" 16169691Skan#include "llvm/Support/Debug.h" 17169691Skan#include "llvm/Support/raw_ostream.h" 18169691Skanusing namespace llvm; 19169691Skan 20169691Skan/// See if the given exception handling personality function is one that we 21169691Skan/// understand. If so, return a description of it; otherwise return Unknown. 22169691SkanEHPersonality llvm::classifyEHPersonality(const Value *Pers) { 23169691Skan const Function *F = 24169691Skan Pers ? dyn_cast<Function>(Pers->stripPointerCasts()) : nullptr; 25169691Skan if (!F) 26169691Skan return EHPersonality::Unknown; 27169691Skan return StringSwitch<EHPersonality>(F->getName()) 28169691Skan .Case("__gnat_eh_personality", EHPersonality::GNU_Ada) 29169691Skan .Case("__gxx_personality_v0", EHPersonality::GNU_CXX) 30169691Skan .Case("__gcc_personality_v0", EHPersonality::GNU_C) 31169691Skan .Case("__objc_personality_v0", EHPersonality::GNU_ObjC) 32169691Skan .Case("_except_handler3", EHPersonality::MSVC_X86SEH) 33169691Skan .Case("_except_handler4", EHPersonality::MSVC_X86SEH) 34169691Skan .Case("__C_specific_handler", EHPersonality::MSVC_Win64SEH) 35169691Skan .Case("__CxxFrameHandler3", EHPersonality::MSVC_CXX) 36169691Skan .Case("ProcessCLRException", EHPersonality::CoreCLR) 37169691Skan .Default(EHPersonality::Unknown); 38169691Skan} 39169691Skan 40169691Skanbool llvm::canSimplifyInvokeNoUnwind(const Function *F) { 41169691Skan EHPersonality Personality = classifyEHPersonality(F->getPersonalityFn()); 42169691Skan // We can't simplify any invokes to nounwind functions if the personality 43169691Skan // function wants to catch asynch exceptions. The nounwind attribute only 44169691Skan // implies that the function does not throw synchronous exceptions. 45169691Skan return !isAsynchronousEHPersonality(Personality); 46169691Skan} 47169691Skan 48169691SkanDenseMap<BasicBlock *, ColorVector> llvm::colorEHFunclets(Function &F) { 49169691Skan SmallVector<std::pair<BasicBlock *, BasicBlock *>, 16> Worklist; 50169691Skan BasicBlock *EntryBlock = &F.getEntryBlock(); 51169691Skan DenseMap<BasicBlock *, ColorVector> BlockColors; 52169691Skan 53169691Skan // Build up the color map, which maps each block to its set of 'colors'. 54169691Skan // For any block B the "colors" of B are the set of funclets F (possibly 55169691Skan // including a root "funclet" representing the main function) such that 56169691Skan // F will need to directly contain B or a copy of B (where the term "directly 57169691Skan // contain" is used to distinguish from being "transitively contained" in 58169691Skan // a nested funclet). 59169691Skan // 60169691Skan // Note: Despite not being a funclet in the truest sense, a catchswitch is 61169691Skan // considered to belong to its own funclet for the purposes of coloring. 62169691Skan 63169691Skan DEBUG_WITH_TYPE("winehprepare-coloring", dbgs() << "\nColoring funclets for " 64169691Skan << F.getName() << "\n"); 65169691Skan 66169691Skan Worklist.push_back({EntryBlock, EntryBlock}); 67169691Skan 68169691Skan while (!Worklist.empty()) { 69169691Skan BasicBlock *Visiting; 70169691Skan BasicBlock *Color; 71169691Skan std::tie(Visiting, Color) = Worklist.pop_back_val(); 72169691Skan DEBUG_WITH_TYPE("winehprepare-coloring", 73169691Skan dbgs() << "Visiting " << Visiting->getName() << ", " 74169691Skan << Color->getName() << "\n"); 75169691Skan Instruction *VisitingHead = Visiting->getFirstNonPHI(); 76169691Skan if (VisitingHead->isEHPad()) { 77169691Skan // Mark this funclet head as a member of itself. 78169691Skan Color = Visiting; 79169691Skan } 80169691Skan // Note that this is a member of the given color. 81169691Skan ColorVector &Colors = BlockColors[Visiting]; 82169691Skan if (std::find(Colors.begin(), Colors.end(), Color) == Colors.end()) 83169691Skan Colors.push_back(Color); 84169691Skan else 85169691Skan continue; 86169691Skan 87169691Skan DEBUG_WITH_TYPE("winehprepare-coloring", 88169691Skan dbgs() << " Assigned color \'" << Color->getName() 89169691Skan << "\' to block \'" << Visiting->getName() 90169691Skan << "\'.\n"); 91169691Skan 92169691Skan BasicBlock *SuccColor = Color; 93169691Skan TerminatorInst *Terminator = Visiting->getTerminator(); 94169691Skan if (auto *CatchRet = dyn_cast<CatchReturnInst>(Terminator)) { 95169691Skan Value *ParentPad = CatchRet->getParentPad(); 96169691Skan if (isa<ConstantTokenNone>(ParentPad)) 97169691Skan SuccColor = EntryBlock; 98169691Skan else 99169691Skan SuccColor = cast<Instruction>(ParentPad)->getParent(); 100169691Skan } 101169691Skan 102169691Skan for (BasicBlock *Succ : successors(Visiting)) 103169691Skan Worklist.push_back({Succ, SuccColor}); 104169691Skan } 105169691Skan return BlockColors; 106169691Skan} 107169691Skan