llvm/lib/CodeGen/GCMetadata.cpp

   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/ADT/StringExtras.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     ListSeparator LS(",");
 126     for (const GCRoot &R : make_range(FD->live_begin(PI), FD->live_end(PI)))
 127       OS << LS << " " << R.Num;
 128
 129     OS << " }\n";
 130   }
 131
 132   return false;
 133 }
 134
 135 bool Printer::doFinalization(Module &M) {
 136   GCModuleInfo *GMI = getAnalysisIfAvailable<GCModuleInfo>();
 137   assert(GMI && "Printer didn't require GCModuleInfo?!");
 138   GMI->clear();
 139   return false;
 140 }
 141
 142 GCStrategy *GCModuleInfo::getGCStrategy(const StringRef Name) {
 143   // TODO: Arguably, just doing a linear search would be faster for small N
 144   auto NMI = GCStrategyMap.find(Name);
 145   if (NMI != GCStrategyMap.end())
 146     return NMI->getValue();
 147
 148   std::unique_ptr<GCStrategy> S = llvm::getGCStrategy(Name);
 149   S->Name = std::string(Name);
 150   GCStrategyMap[Name] = S.get();
 151   GCStrategyList.push_back(std::move(S));
 152   return GCStrategyList.back().get();
 153 }