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:
Printer(raw_ostream & OS)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
GCFunctionInfo(const Function & F,GCStrategy & S)48 GCFunctionInfo::GCFunctionInfo(const Function &F, GCStrategy &S)
49 : F(F), S(S), FrameSize(~0LL) {}
50
~GCFunctionInfo()51 GCFunctionInfo::~GCFunctionInfo() {}
52
53 // -----------------------------------------------------------------------------
54
55 char GCModuleInfo::ID = 0;
56
GCModuleInfo()57 GCModuleInfo::GCModuleInfo() : ImmutablePass(ID) {
58 initializeGCModuleInfoPass(*PassRegistry::getPassRegistry());
59 }
60
getFunctionInfo(const Function & F)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
clear()76 void GCModuleInfo::clear() {
77 Functions.clear();
78 FInfoMap.clear();
79 GCStrategyList.clear();
80 }
81
82 // -----------------------------------------------------------------------------
83
84 char Printer::ID = 0;
85
createGCInfoPrinter(raw_ostream & OS)86 FunctionPass *llvm::createGCInfoPrinter(raw_ostream &OS) {
87 return new Printer(OS);
88 }
89
getPassName() const90 const char *Printer::getPassName() const {
91 return "Print Garbage Collector Information";
92 }
93
getAnalysisUsage(AnalysisUsage & AU) const94 void Printer::getAnalysisUsage(AnalysisUsage &AU) const {
95 FunctionPass::getAnalysisUsage(AU);
96 AU.setPreservesAll();
97 AU.addRequired<GCModuleInfo>();
98 }
99
DescKind(GC::PointKind Kind)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
runOnFunction(Function & F)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
doFinalization(Module & M)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
getGCStrategy(const StringRef Name)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 }
178