lib/CodeGen/GCMetadata.cpp

   1 //===-- GCMetadata.cpp - Garbage collector metadata -----------------------===//
   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 // This file implements the GCFunctionInfo class and GCModuleInfo pass.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "llvm/CodeGen/GCMetadata.h"
  15 #include "llvm/CodeGen/GCStrategy.h"
  16 #include "llvm/CodeGen/MachineFrameInfo.h"
  17 #include "llvm/CodeGen/Passes.h"
  18 #include "llvm/IR/Function.h"
  19 #include "llvm/MC/MCSymbol.h"
  20 #include "llvm/Pass.h"
  21 #include "llvm/Support/Debug.h"
  22 #include "llvm/Support/ErrorHandling.h"
  23 #include "llvm/Support/raw_ostream.h"
  24 using namespace llvm;
  25
  26 namespace {
  27
  28 class Printer : public FunctionPass {
  29   static char ID;
  30   raw_ostream &OS;
  31
  32 public:
  33   explicit Printer(raw_ostream &OS) : FunctionPass(ID), OS(OS) {}
  34
  35   const char *getPassName() const override;
  36   void getAnalysisUsage(AnalysisUsage &AU) const override;
  37
  38   bool runOnFunction(Function &F) override;
  39   bool doFinalization(Module &M) override;
  40 };
  41 }
  42
  43 INITIALIZE_PASS(GCModuleInfo, "collector-metadata",
  44                 "Create Garbage Collector Module Metadata", false, false)
  45
  46 // -----------------------------------------------------------------------------
  47
  48 GCFunctionInfo::GCFunctionInfo(const Function &F, GCStrategy &S)
  49     : F(F), S(S), FrameSize(~0LL) {}
  50
  51 GCFunctionInfo::~GCFunctionInfo() {}
  52
  53 // -----------------------------------------------------------------------------
  54
  55 char GCModuleInfo::ID = 0;
  56
  57 GCModuleInfo::GCModuleInfo() : ImmutablePass(ID) {
  58   initializeGCModuleInfoPass(*PassRegistry::getPassRegistry());
  59 }
  60
  61 GCFunctionInfo &GCModuleInfo::getFunctionInfo(const Function &F) {
  62   assert(!F.isDeclaration() && "Can only get GCFunctionInfo for a definition!");
  63   assert(F.hasGC());
  64
  65   finfo_map_type::iterator I = FInfoMap.find(&F);
  66   if (I != FInfoMap.end())
  67     return *I->second;
  68
  69   GCStrategy *S = getGCStrategy(F.getGC());
  70   Functions.push_back(make_unique<GCFunctionInfo>(F, *S));
  71   GCFunctionInfo *GFI = Functions.back().get();
  72   FInfoMap[&F] = GFI;
  73   return *GFI;
  74 }
  75
  76 void GCModuleInfo::clear() {
  77   Functions.clear();
  78   FInfoMap.clear();
  79   GCStrategyList.clear();
  80 }
  81
  82 // -----------------------------------------------------------------------------
  83
  84 char Printer::ID = 0;
  85
  86 FunctionPass *llvm::createGCInfoPrinter(raw_ostream &OS) {
  87   return new Printer(OS);
  88 }
  89
  90 const char *Printer::getPassName() const {
  91   return "Print Garbage Collector Information";
  92 }
  93
  94 void Printer::getAnalysisUsage(AnalysisUsage &AU) const {
  95   FunctionPass::getAnalysisUsage(AU);
  96   AU.setPreservesAll();
  97   AU.addRequired<GCModuleInfo>();
  98 }
  99
 100 static const char *DescKind(GC::PointKind Kind) {
 101   switch (Kind) {
 102   case GC::PreCall:
 103     return "pre-call";
 104   case GC::PostCall:
 105     return "post-call";
 106   }
 107   llvm_unreachable("Invalid point kind");
 108 }
 109
 110 bool Printer::runOnFunction(Function &F) {
 111   if (F.hasGC())
 112     return false;
 113
 114   GCFunctionInfo *FD = &getAnalysis<GCModuleInfo>().getFunctionInfo(F);
 115
 116   OS << "GC roots for " << FD->getFunction().getName() << ":\n";
 117   for (GCFunctionInfo::roots_iterator RI = FD->roots_begin(),
 118                                       RE = FD->roots_end();
 119        RI != RE; ++RI)
 120     OS << "\t" << RI->Num << "\t" << RI->StackOffset << "[sp]\n";
 121
 122   OS << "GC safe points for " << FD->getFunction().getName() << ":\n";
 123   for (GCFunctionInfo::iterator PI = FD->begin(), PE = FD->end(); PI != PE;
 124        ++PI) {
 125
 126     OS << "\t" << PI->Label->getName() << ": " << DescKind(PI->Kind)
 127        << ", live = {";
 128
 129     for (GCFunctionInfo::live_iterator RI = FD->live_begin(PI),
 130                                        RE = FD->live_end(PI);
 131          ;) {
 132       OS << " " << RI->Num;
 133       if (++RI == RE)
 134         break;
 135       OS << ",";
 136     }
 137
 138     OS << " }\n";
 139   }
 140
 141   return false;
 142 }
 143
 144 bool Printer::doFinalization(Module &M) {
 145   GCModuleInfo *GMI = getAnalysisIfAvailable<GCModuleInfo>();
 146   assert(GMI && "Printer didn't require GCModuleInfo?!");
 147   GMI->clear();
 148   return false;
 149 }
 150
 151 GCStrategy *GCModuleInfo::getGCStrategy(const StringRef Name) {
 152   // TODO: Arguably, just doing a linear search would be faster for small N
 153   auto NMI = GCStrategyMap.find(Name);
 154   if (NMI != GCStrategyMap.end())
 155     return NMI->getValue();
 156
 157   for (auto& Entry : GCRegistry::entries()) {
 158     if (Name == Entry.getName()) {
 159       std::unique_ptr<GCStrategy> S = Entry.instantiate();
 160       S->Name = Name;
 161       GCStrategyMap[Name] = S.get();
 162       GCStrategyList.push_back(std::move(S));
 163       return GCStrategyList.back().get();
 164     }
 165   }
 166
 167   if (GCRegistry::begin() == GCRegistry::end()) {
 168     // In normal operation, the registry should not be empty.  There should
 169     // be the builtin GCs if nothing else.  The most likely scenario here is
 170     // that we got here without running the initializers used by the Registry
 171     // itself and it's registration mechanism.
 172     const std::string error = ("unsupported GC: " + Name).str() +
 173       " (did you remember to link and initialize the CodeGen library?)";
 174     report_fatal_error(error);
 175   } else
 176     report_fatal_error(std::string("unsupported GC: ") + Name);
 177 }