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" 18 using 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. 22 EHPersonality 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("__gxx_personality_sj0", EHPersonality::GNU_CXX_SjLj) 31 .Case("__gcc_personality_v0", EHPersonality::GNU_C) 32 .Case("__gcc_personality_sj0", EHPersonality::GNU_C_SjLj) 33 .Case("__objc_personality_v0", EHPersonality::GNU_ObjC) 34 .Case("_except_handler3", EHPersonality::MSVC_X86SEH) 35 .Case("_except_handler4", EHPersonality::MSVC_X86SEH) 36 .Case("__C_specific_handler", EHPersonality::MSVC_Win64SEH) 37 .Case("__CxxFrameHandler3", EHPersonality::MSVC_CXX) 38 .Case("ProcessCLRException", EHPersonality::CoreCLR) 39 .Case("rust_eh_personality", EHPersonality::Rust) 40 .Default(EHPersonality::Unknown); 41 } 42 43 StringRef llvm::getEHPersonalityName(EHPersonality Pers) { 44 switch (Pers) { 45 case EHPersonality::GNU_Ada: return "__gnat_eh_personality"; 46 case EHPersonality::GNU_CXX: return "__gxx_personality_v0"; 47 case EHPersonality::GNU_CXX_SjLj: return "__gxx_personality_sj0"; 48 case EHPersonality::GNU_C: return "__gcc_personality_v0"; 49 case EHPersonality::GNU_C_SjLj: return "__gcc_personality_sj0"; 50 case EHPersonality::GNU_ObjC: return "__objc_personality_v0"; 51 case EHPersonality::MSVC_X86SEH: return "_except_handler3"; 52 case EHPersonality::MSVC_Win64SEH: return "__C_specific_handler"; 53 case EHPersonality::MSVC_CXX: return "__CxxFrameHandler3"; 54 case EHPersonality::CoreCLR: return "ProcessCLRException"; 55 case EHPersonality::Rust: return "rust_eh_personality"; 56 case EHPersonality::Unknown: llvm_unreachable("Unknown EHPersonality!"); 57 } 58 59 llvm_unreachable("Invalid EHPersonality!"); 60 } 61 62 EHPersonality llvm::getDefaultEHPersonality(const Triple &T) { 63 return EHPersonality::GNU_C; 64 } 65 66 bool llvm::canSimplifyInvokeNoUnwind(const Function *F) { 67 EHPersonality Personality = classifyEHPersonality(F->getPersonalityFn()); 68 // We can't simplify any invokes to nounwind functions if the personality 69 // function wants to catch asynch exceptions. The nounwind attribute only 70 // implies that the function does not throw synchronous exceptions. 71 return !isAsynchronousEHPersonality(Personality); 72 } 73 74 DenseMap<BasicBlock *, ColorVector> llvm::colorEHFunclets(Function &F) { 75 SmallVector<std::pair<BasicBlock *, BasicBlock *>, 16> Worklist; 76 BasicBlock *EntryBlock = &F.getEntryBlock(); 77 DenseMap<BasicBlock *, ColorVector> BlockColors; 78 79 // Build up the color map, which maps each block to its set of 'colors'. 80 // For any block B the "colors" of B are the set of funclets F (possibly 81 // including a root "funclet" representing the main function) such that 82 // F will need to directly contain B or a copy of B (where the term "directly 83 // contain" is used to distinguish from being "transitively contained" in 84 // a nested funclet). 85 // 86 // Note: Despite not being a funclet in the truest sense, a catchswitch is 87 // considered to belong to its own funclet for the purposes of coloring. 88 89 DEBUG_WITH_TYPE("winehprepare-coloring", dbgs() << "\nColoring funclets for " 90 << F.getName() << "\n"); 91 92 Worklist.push_back({EntryBlock, EntryBlock}); 93 94 while (!Worklist.empty()) { 95 BasicBlock *Visiting; 96 BasicBlock *Color; 97 std::tie(Visiting, Color) = Worklist.pop_back_val(); 98 DEBUG_WITH_TYPE("winehprepare-coloring", 99 dbgs() << "Visiting " << Visiting->getName() << ", " 100 << Color->getName() << "\n"); 101 Instruction *VisitingHead = Visiting->getFirstNonPHI(); 102 if (VisitingHead->isEHPad()) { 103 // Mark this funclet head as a member of itself. 104 Color = Visiting; 105 } 106 // Note that this is a member of the given color. 107 ColorVector &Colors = BlockColors[Visiting]; 108 if (!is_contained(Colors, Color)) 109 Colors.push_back(Color); 110 else 111 continue; 112 113 DEBUG_WITH_TYPE("winehprepare-coloring", 114 dbgs() << " Assigned color \'" << Color->getName() 115 << "\' to block \'" << Visiting->getName() 116 << "\'.\n"); 117 118 BasicBlock *SuccColor = Color; 119 TerminatorInst *Terminator = Visiting->getTerminator(); 120 if (auto *CatchRet = dyn_cast<CatchReturnInst>(Terminator)) { 121 Value *ParentPad = CatchRet->getCatchSwitchParentPad(); 122 if (isa<ConstantTokenNone>(ParentPad)) 123 SuccColor = EntryBlock; 124 else 125 SuccColor = cast<Instruction>(ParentPad)->getParent(); 126 } 127 128 for (BasicBlock *Succ : successors(Visiting)) 129 Worklist.push_back({Succ, SuccColor}); 130 } 131 return BlockColors; 132 } 133