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/ADT/STLExtras.h"
  15 #include "llvm/CodeGen/GCMetadata.h"
  16 #include "llvm/CodeGen/GCStrategy.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/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(llvm::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 static const char *DescKind(GC::PointKind Kind) {
 107   switch (Kind) {
 108   case GC::PreCall:
 109     return "pre-call";
 110   case GC::PostCall:
 111     return "post-call";
 112   }
 113   llvm_unreachable("Invalid point kind");
 114 }
 115
 116 bool Printer::runOnFunction(Function &F) {
 117   if (F.hasGC())
 118     return false;
 119
 120   GCFunctionInfo *FD = &getAnalysis<GCModuleInfo>().getFunctionInfo(F);
 121
 122   OS << "GC roots for " << FD->getFunction().getName() << ":\n";
 123   for (GCFunctionInfo::roots_iterator RI = FD->roots_begin(),
 124                                       RE = FD->roots_end();
 125        RI != RE; ++RI)
 126     OS << "\t" << RI->Num << "\t" << RI->StackOffset << "[sp]\n";
 127
 128   OS << "GC safe points for " << FD->getFunction().getName() << ":\n";
 129   for (GCFunctionInfo::iterator PI = FD->begin(), PE = FD->end(); PI != PE;
 130        ++PI) {
 131
 132     OS << "\t" << PI->Label->getName() << ": " << DescKind(PI->Kind)
 133        << ", live = {";
 134
 135     for (GCFunctionInfo::live_iterator RI = FD->live_begin(PI),
 136                                        RE = FD->live_end(PI);
 137          ;) {
 138       OS << " " << RI->Num;
 139       if (++RI == RE)
 140         break;
 141       OS << ",";
 142     }
 143
 144     OS << " }\n";
 145   }
 146
 147   return false;
 148 }
 149
 150 bool Printer::doFinalization(Module &M) {
 151   GCModuleInfo *GMI = getAnalysisIfAvailable<GCModuleInfo>();
 152   assert(GMI && "Printer didn't require GCModuleInfo?!");
 153   GMI->clear();
 154   return false;
 155 }
 156
 157 GCStrategy *GCModuleInfo::getGCStrategy(const StringRef Name) {
 158   // TODO: Arguably, just doing a linear search would be faster for small N
 159   auto NMI = GCStrategyMap.find(Name);
 160   if (NMI != GCStrategyMap.end())
 161     return NMI->getValue();
 162
 163   for (auto& Entry : GCRegistry::entries()) {
 164     if (Name == Entry.getName()) {
 165       std::unique_ptr<GCStrategy> S = Entry.instantiate();
 166       S->Name = Name;
 167       GCStrategyMap[Name] = S.get();
 168       GCStrategyList.push_back(std::move(S));
 169       return GCStrategyList.back().get();
 170     }
 171   }
 172
 173   if (GCRegistry::begin() == GCRegistry::end()) {
 174     // In normal operation, the registry should not be empty.  There should
 175     // be the builtin GCs if nothing else.  The most likely scenario here is
 176     // that we got here without running the initializers used by the Registry
 177     // itself and it's registration mechanism.
 178     const std::string error = ("unsupported GC: " + Name).str() +
 179       " (did you remember to link and initialize the CodeGen library?)";
 180     report_fatal_error(error);
 181   } else
 182     report_fatal_error(std::string("unsupported GC: ") + Name);
 183 }