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/MachineFrameInfo.h"
16 #include "llvm/CodeGen/Passes.h"
17 #include "llvm/IR/Function.h"
18 #include "llvm/IR/GCStrategy.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 = F.getGCStrategy();
70   if (!S) {
71     std::string error = std::string("unsupported GC: ") + F.getGC();
72     report_fatal_error(error);
73   }
74   // Save the fact this strategy is associated with this module.  Note that
75   // these are non-owning references, the GCStrategy remains owned by the
76   // Context.
77   StrategyList.push_back(S);
78   Functions.push_back(make_unique<GCFunctionInfo>(F, *S));
79   GCFunctionInfo *GFI = Functions.back().get();
80   FInfoMap[&F] = GFI;
81   return *GFI;
82 }
83 
84 void GCModuleInfo::clear() {
85   Functions.clear();
86   FInfoMap.clear();
87   StrategyList.clear();
88 }
89 
90 // -----------------------------------------------------------------------------
91 
92 char Printer::ID = 0;
93 
94 FunctionPass *llvm::createGCInfoPrinter(raw_ostream &OS) {
95   return new Printer(OS);
96 }
97 
98 const char *Printer::getPassName() const {
99   return "Print Garbage Collector Information";
100 }
101 
102 void Printer::getAnalysisUsage(AnalysisUsage &AU) const {
103   FunctionPass::getAnalysisUsage(AU);
104   AU.setPreservesAll();
105   AU.addRequired<GCModuleInfo>();
106 }
107 
108 static const char *DescKind(GC::PointKind Kind) {
109   switch (Kind) {
110   case GC::Loop:
111     return "loop";
112   case GC::Return:
113     return "return";
114   case GC::PreCall:
115     return "pre-call";
116   case GC::PostCall:
117     return "post-call";
118   }
119   llvm_unreachable("Invalid point kind");
120 }
121 
122 bool Printer::runOnFunction(Function &F) {
123   if (F.hasGC())
124     return false;
125 
126   GCFunctionInfo *FD = &getAnalysis<GCModuleInfo>().getFunctionInfo(F);
127 
128   OS << "GC roots for " << FD->getFunction().getName() << ":\n";
129   for (GCFunctionInfo::roots_iterator RI = FD->roots_begin(),
130                                       RE = FD->roots_end();
131        RI != RE; ++RI)
132     OS << "\t" << RI->Num << "\t" << RI->StackOffset << "[sp]\n";
133 
134   OS << "GC safe points for " << FD->getFunction().getName() << ":\n";
135   for (GCFunctionInfo::iterator PI = FD->begin(), PE = FD->end(); PI != PE;
136        ++PI) {
137 
138     OS << "\t" << PI->Label->getName() << ": " << DescKind(PI->Kind)
139        << ", live = {";
140 
141     for (GCFunctionInfo::live_iterator RI = FD->live_begin(PI),
142                                        RE = FD->live_end(PI);
143          ;) {
144       OS << " " << RI->Num;
145       if (++RI == RE)
146         break;
147       OS << ",";
148     }
149 
150     OS << " }\n";
151   }
152 
153   return false;
154 }
155 
156 bool Printer::doFinalization(Module &M) {
157   GCModuleInfo *GMI = getAnalysisIfAvailable<GCModuleInfo>();
158   assert(GMI && "Printer didn't require GCModuleInfo?!");
159   GMI->clear();
160   return false;
161 }
162