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/CFG.h" 13#include "llvm/IR/Constants.h" 14#include "llvm/IR/Function.h" 15#include "llvm/IR/Instructions.h" 16#include "llvm/Support/Debug.h" 17#include "llvm/Support/raw_ostream.h" 18using namespace llvm; 19 20/// See if the given exception handling personality function is one that we 21/// understand. If so, return a description of it; otherwise return Unknown. 22EHPersonality llvm::classifyEHPersonality(const Value *Pers) { 23 const Function *F = 24 Pers ? dyn_cast<Function>(Pers->stripPointerCasts()) : nullptr; 25 if (!F) 26 return EHPersonality::Unknown; 27 return StringSwitch<EHPersonality>(F->getName()) 28 .Case("__gnat_eh_personality", EHPersonality::GNU_Ada) 29 .Case("__gxx_personality_v0", EHPersonality::GNU_CXX) 30 .Case("__gcc_personality_v0", EHPersonality::GNU_C) 31 .Case("__objc_personality_v0", EHPersonality::GNU_ObjC) 32 .Case("_except_handler3", EHPersonality::MSVC_X86SEH) 33 .Case("_except_handler4", EHPersonality::MSVC_X86SEH) 34 .Case("__C_specific_handler", EHPersonality::MSVC_Win64SEH) 35 .Case("__CxxFrameHandler3", EHPersonality::MSVC_CXX) 36 .Case("ProcessCLRException", EHPersonality::CoreCLR) 37 .Default(EHPersonality::Unknown); 38} 39 40bool llvm::canSimplifyInvokeNoUnwind(const Function *F) { 41 EHPersonality Personality = classifyEHPersonality(F->getPersonalityFn()); 42 // We can't simplify any invokes to nounwind functions if the personality 43 // function wants to catch asynch exceptions. The nounwind attribute only 44 // implies that the function does not throw synchronous exceptions. 45 return !isAsynchronousEHPersonality(Personality); 46} 47 48DenseMap<BasicBlock *, ColorVector> llvm::colorEHFunclets(Function &F) { 49 SmallVector<std::pair<BasicBlock *, BasicBlock *>, 16> Worklist; 50 BasicBlock *EntryBlock = &F.getEntryBlock(); 51 DenseMap<BasicBlock *, ColorVector> BlockColors; 52 53 // Build up the color map, which maps each block to its set of 'colors'. 54 // For any block B the "colors" of B are the set of funclets F (possibly 55 // including a root "funclet" representing the main function) such that 56 // F will need to directly contain B or a copy of B (where the term "directly 57 // contain" is used to distinguish from being "transitively contained" in 58 // a nested funclet). 59 // 60 // Note: Despite not being a funclet in the truest sense, a catchswitch is 61 // considered to belong to its own funclet for the purposes of coloring. 62 63 DEBUG_WITH_TYPE("winehprepare-coloring", dbgs() << "\nColoring funclets for " 64 << F.getName() << "\n"); 65 66 Worklist.push_back({EntryBlock, EntryBlock}); 67 68 while (!Worklist.empty()) { 69 BasicBlock *Visiting; 70 BasicBlock *Color; 71 std::tie(Visiting, Color) = Worklist.pop_back_val(); 72 DEBUG_WITH_TYPE("winehprepare-coloring", 73 dbgs() << "Visiting " << Visiting->getName() << ", " 74 << Color->getName() << "\n"); 75 Instruction *VisitingHead = Visiting->getFirstNonPHI(); 76 if (VisitingHead->isEHPad()) { 77 // Mark this funclet head as a member of itself. 78 Color = Visiting; 79 } 80 // Note that this is a member of the given color. 81 ColorVector &Colors = BlockColors[Visiting]; 82 if (std::find(Colors.begin(), Colors.end(), Color) == Colors.end()) 83 Colors.push_back(Color); 84 else 85 continue; 86 87 DEBUG_WITH_TYPE("winehprepare-coloring", 88 dbgs() << " Assigned color \'" << Color->getName() 89 << "\' to block \'" << Visiting->getName() 90 << "\'.\n"); 91 92 BasicBlock *SuccColor = Color; 93 TerminatorInst *Terminator = Visiting->getTerminator(); 94 if (auto *CatchRet = dyn_cast<CatchReturnInst>(Terminator)) { 95 Value *ParentPad = CatchRet->getParentPad(); 96 if (isa<ConstantTokenNone>(ParentPad)) 97 SuccColor = EntryBlock; 98 else 99 SuccColor = cast<Instruction>(ParentPad)->getParent(); 100 } 101 102 for (BasicBlock *Succ : successors(Visiting)) 103 Worklist.push_back({Succ, SuccColor}); 104 } 105 return BlockColors; 106} 107