1 //===-- GCMetadata.cpp - Garbage collector metadata -----------------------===// 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 // This file implements the GCFunctionInfo class and GCModuleInfo pass. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #include "llvm/CodeGen/GCMetadata.h" 14 #include "llvm/ADT/STLExtras.h" 15 #include "llvm/CodeGen/GCStrategy.h" 16 #include "llvm/CodeGen/Passes.h" 17 #include "llvm/IR/Function.h" 18 #include "llvm/InitializePasses.h" 19 #include "llvm/MC/MCSymbol.h" 20 #include "llvm/Pass.h" 21 #include "llvm/Support/ErrorHandling.h" 22 #include "llvm/Support/raw_ostream.h" 23 #include <algorithm> 24 #include <cassert> 25 #include <memory> 26 #include <string> 27 28 using namespace llvm; 29 30 namespace { 31 32 class Printer : public FunctionPass { 33 static char ID; 34 35 raw_ostream &OS; 36 37 public: 38 explicit Printer(raw_ostream &OS) : FunctionPass(ID), OS(OS) {} 39 40 StringRef getPassName() const override; 41 void getAnalysisUsage(AnalysisUsage &AU) const override; 42 43 bool runOnFunction(Function &F) override; 44 bool doFinalization(Module &M) override; 45 }; 46 47 } // end anonymous namespace 48 49 INITIALIZE_PASS(GCModuleInfo, "collector-metadata", 50 "Create Garbage Collector Module Metadata", false, false) 51 52 // ----------------------------------------------------------------------------- 53 54 GCFunctionInfo::GCFunctionInfo(const Function &F, GCStrategy &S) 55 : F(F), S(S), FrameSize(~0LL) {} 56 57 GCFunctionInfo::~GCFunctionInfo() = default; 58 59 // ----------------------------------------------------------------------------- 60 61 char GCModuleInfo::ID = 0; 62 63 GCModuleInfo::GCModuleInfo() : ImmutablePass(ID) { 64 initializeGCModuleInfoPass(*PassRegistry::getPassRegistry()); 65 } 66 67 GCFunctionInfo &GCModuleInfo::getFunctionInfo(const Function &F) { 68 assert(!F.isDeclaration() && "Can only get GCFunctionInfo for a definition!"); 69 assert(F.hasGC()); 70 71 finfo_map_type::iterator I = FInfoMap.find(&F); 72 if (I != FInfoMap.end()) 73 return *I->second; 74 75 GCStrategy *S = getGCStrategy(F.getGC()); 76 Functions.push_back(std::make_unique<GCFunctionInfo>(F, *S)); 77 GCFunctionInfo *GFI = Functions.back().get(); 78 FInfoMap[&F] = GFI; 79 return *GFI; 80 } 81 82 void GCModuleInfo::clear() { 83 Functions.clear(); 84 FInfoMap.clear(); 85 GCStrategyList.clear(); 86 } 87 88 // ----------------------------------------------------------------------------- 89 90 char Printer::ID = 0; 91 92 FunctionPass *llvm::createGCInfoPrinter(raw_ostream &OS) { 93 return new Printer(OS); 94 } 95 96 StringRef Printer::getPassName() const { 97 return "Print Garbage Collector Information"; 98 } 99 100 void Printer::getAnalysisUsage(AnalysisUsage &AU) const { 101 FunctionPass::getAnalysisUsage(AU); 102 AU.setPreservesAll(); 103 AU.addRequired<GCModuleInfo>(); 104 } 105 106 bool Printer::runOnFunction(Function &F) { 107 if (F.hasGC()) 108 return false; 109 110 GCFunctionInfo *FD = &getAnalysis<GCModuleInfo>().getFunctionInfo(F); 111 112 OS << "GC roots for " << FD->getFunction().getName() << ":\n"; 113 for (GCFunctionInfo::roots_iterator RI = FD->roots_begin(), 114 RE = FD->roots_end(); 115 RI != RE; ++RI) 116 OS << "\t" << RI->Num << "\t" << RI->StackOffset << "[sp]\n"; 117 118 OS << "GC safe points for " << FD->getFunction().getName() << ":\n"; 119 for (GCFunctionInfo::iterator PI = FD->begin(), PE = FD->end(); PI != PE; 120 ++PI) { 121 122 OS << "\t" << PI->Label->getName() << ": " << "post-call" 123 << ", live = {"; 124 125 for (GCFunctionInfo::live_iterator RI = FD->live_begin(PI), 126 RE = FD->live_end(PI); 127 ;) { 128 OS << " " << RI->Num; 129 if (++RI == RE) 130 break; 131 OS << ","; 132 } 133 134 OS << " }\n"; 135 } 136 137 return false; 138 } 139 140 bool Printer::doFinalization(Module &M) { 141 GCModuleInfo *GMI = getAnalysisIfAvailable<GCModuleInfo>(); 142 assert(GMI && "Printer didn't require GCModuleInfo?!"); 143 GMI->clear(); 144 return false; 145 } 146 147 GCStrategy *GCModuleInfo::getGCStrategy(const StringRef Name) { 148 // TODO: Arguably, just doing a linear search would be faster for small N 149 auto NMI = GCStrategyMap.find(Name); 150 if (NMI != GCStrategyMap.end()) 151 return NMI->getValue(); 152 153 for (auto& Entry : GCRegistry::entries()) { 154 if (Name == Entry.getName()) { 155 std::unique_ptr<GCStrategy> S = Entry.instantiate(); 156 S->Name = std::string(Name); 157 GCStrategyMap[Name] = S.get(); 158 GCStrategyList.push_back(std::move(S)); 159 return GCStrategyList.back().get(); 160 } 161 } 162 163 if (GCRegistry::begin() == GCRegistry::end()) { 164 // In normal operation, the registry should not be empty. There should 165 // be the builtin GCs if nothing else. The most likely scenario here is 166 // that we got here without running the initializers used by the Registry 167 // itself and it's registration mechanism. 168 const std::string error = ("unsupported GC: " + Name).str() + 169 " (did you remember to link and initialize the CodeGen library?)"; 170 report_fatal_error(error); 171 } else 172 report_fatal_error(std::string("unsupported GC: ") + Name); 173 } 174