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 
36     const char *getPassName() const override;
37     void getAnalysisUsage(AnalysisUsage &AU) const override;
38 
39     bool runOnFunction(Function &F) override;
40     bool doFinalization(Module &M) override;
41   };
42 
43 }
44 
45 INITIALIZE_PASS(GCModuleInfo, "collector-metadata",
46                 "Create Garbage Collector Module Metadata", false, false)
47 
48 // -----------------------------------------------------------------------------
49 
50 GCFunctionInfo::GCFunctionInfo(const Function &F, GCStrategy &S)
51   : F(F), S(S), FrameSize(~0LL) {}
52 
53 GCFunctionInfo::~GCFunctionInfo() {}
54 
55 // -----------------------------------------------------------------------------
56 
57 char GCModuleInfo::ID = 0;
58 
59 GCModuleInfo::GCModuleInfo()
60     : ImmutablePass(ID) {
61   initializeGCModuleInfoPass(*PassRegistry::getPassRegistry());
62 }
63 
64 GCStrategy *GCModuleInfo::getOrCreateStrategy(const Module *M,
65                                               const std::string &Name) {
66   strategy_map_type::iterator NMI = StrategyMap.find(Name);
67   if (NMI != StrategyMap.end())
68     return NMI->getValue();
69 
70   for (GCRegistry::iterator I = GCRegistry::begin(),
71                             E = GCRegistry::end(); I != E; ++I) {
72     if (Name == I->getName()) {
73       std::unique_ptr<GCStrategy> S = I->instantiate();
74       S->Name = Name;
75       StrategyMap[Name] = S.get();
76       StrategyList.push_back(std::move(S));
77       return StrategyList.back().get();
78     }
79   }
80 
81   dbgs() << "unsupported GC: " << Name << "\n";
82   llvm_unreachable(nullptr);
83 }
84 
85 GCFunctionInfo &GCModuleInfo::getFunctionInfo(const Function &F) {
86   assert(!F.isDeclaration() && "Can only get GCFunctionInfo for a definition!");
87   assert(F.hasGC());
88 
89   finfo_map_type::iterator I = FInfoMap.find(&F);
90   if (I != FInfoMap.end())
91     return *I->second;
92 
93   GCStrategy *S = getOrCreateStrategy(F.getParent(), F.getGC());
94   Functions.push_back(make_unique<GCFunctionInfo>(F, *S));
95   GCFunctionInfo *GFI = Functions.back().get();
96   FInfoMap[&F] = GFI;
97   return *GFI;
98 }
99 
100 void GCModuleInfo::clear() {
101   Functions.clear();
102   FInfoMap.clear();
103   StrategyMap.clear();
104   StrategyList.clear();
105 }
106 
107 // -----------------------------------------------------------------------------
108 
109 char Printer::ID = 0;
110 
111 FunctionPass *llvm::createGCInfoPrinter(raw_ostream &OS) {
112   return new Printer(OS);
113 }
114 
115 
116 const char *Printer::getPassName() const {
117   return "Print Garbage Collector Information";
118 }
119 
120 void Printer::getAnalysisUsage(AnalysisUsage &AU) const {
121   FunctionPass::getAnalysisUsage(AU);
122   AU.setPreservesAll();
123   AU.addRequired<GCModuleInfo>();
124 }
125 
126 static const char *DescKind(GC::PointKind Kind) {
127   switch (Kind) {
128     case GC::Loop:     return "loop";
129     case GC::Return:   return "return";
130     case GC::PreCall:  return "pre-call";
131     case GC::PostCall: return "post-call";
132   }
133   llvm_unreachable("Invalid point kind");
134 }
135 
136 bool Printer::runOnFunction(Function &F) {
137   if (F.hasGC()) return false;
138 
139   GCFunctionInfo *FD = &getAnalysis<GCModuleInfo>().getFunctionInfo(F);
140 
141   OS << "GC roots for " << FD->getFunction().getName() << ":\n";
142   for (GCFunctionInfo::roots_iterator RI = FD->roots_begin(),
143                                       RE = FD->roots_end(); RI != RE; ++RI)
144     OS << "\t" << RI->Num << "\t" << RI->StackOffset << "[sp]\n";
145 
146   OS << "GC safe points for " << FD->getFunction().getName() << ":\n";
147   for (GCFunctionInfo::iterator PI = FD->begin(),
148                                 PE = FD->end(); PI != PE; ++PI) {
149 
150     OS << "\t" << PI->Label->getName() << ": "
151        << DescKind(PI->Kind) << ", live = {";
152 
153     for (GCFunctionInfo::live_iterator RI = FD->live_begin(PI),
154                                        RE = FD->live_end(PI);;) {
155       OS << " " << RI->Num;
156       if (++RI == RE)
157         break;
158       OS << ",";
159     }
160 
161     OS << " }\n";
162   }
163 
164   return false;
165 }
166 
167 bool Printer::doFinalization(Module &M) {
168   GCModuleInfo *GMI = getAnalysisIfAvailable<GCModuleInfo>();
169   assert(GMI && "Printer didn't require GCModuleInfo?!");
170   GMI->clear();
171   return false;
172 }
173