1 //===- PassRegistry.cpp - Pass Registration Implementation ----------------===//
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 PassRegistry, with which passes are registered on
11 // initialization, and supports the PassManager in dependency resolution.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #include "llvm/PassRegistry.h"
16 #include "llvm/ADT/DenseMap.h"
17 #include "llvm/ADT/SmallPtrSet.h"
18 #include "llvm/ADT/StringMap.h"
19 #include "llvm/IR/Function.h"
20 #include "llvm/PassSupport.h"
21 #include "llvm/Support/Compiler.h"
22 #include "llvm/Support/ManagedStatic.h"
23 #include "llvm/Support/Mutex.h"
24 #include "llvm/Support/RWMutex.h"
25 #include <vector>
26 
27 using namespace llvm;
28 
29 // FIXME: We use ManagedStatic to erase the pass registrar on shutdown.
30 // Unfortunately, passes are registered with static ctors, and having
31 // llvm_shutdown clear this map prevents successful resurrection after
32 // llvm_shutdown is run.  Ideally we should find a solution so that we don't
33 // leak the map, AND can still resurrect after shutdown.
34 static ManagedStatic<PassRegistry> PassRegistryObj;
35 PassRegistry *PassRegistry::getPassRegistry() {
36   return &*PassRegistryObj;
37 }
38 
39 static ManagedStatic<sys::SmartRWMutex<true> > Lock;
40 
41 //===----------------------------------------------------------------------===//
42 // PassRegistryImpl
43 //
44 
45 namespace {
46 struct PassRegistryImpl {
47   /// PassInfoMap - Keep track of the PassInfo object for each registered pass.
48   typedef DenseMap<const void*, const PassInfo*> MapType;
49   MapType PassInfoMap;
50 
51   typedef StringMap<const PassInfo*> StringMapType;
52   StringMapType PassInfoStringMap;
53 
54   /// AnalysisGroupInfo - Keep track of information for each analysis group.
55   struct AnalysisGroupInfo {
56     SmallPtrSet<const PassInfo *, 8> Implementations;
57   };
58   DenseMap<const PassInfo*, AnalysisGroupInfo> AnalysisGroupInfoMap;
59 
60   std::vector<std::unique_ptr<const PassInfo>> ToFree;
61   std::vector<PassRegistrationListener*> Listeners;
62 };
63 } // end anonymous namespace
64 
65 void *PassRegistry::getImpl() const {
66   if (!pImpl)
67     pImpl = new PassRegistryImpl();
68   return pImpl;
69 }
70 
71 //===----------------------------------------------------------------------===//
72 // Accessors
73 //
74 
75 PassRegistry::~PassRegistry() {
76   sys::SmartScopedWriter<true> Guard(*Lock);
77   PassRegistryImpl *Impl = static_cast<PassRegistryImpl*>(pImpl);
78   delete Impl;
79   pImpl = nullptr;
80 }
81 
82 const PassInfo *PassRegistry::getPassInfo(const void *TI) const {
83   sys::SmartScopedReader<true> Guard(*Lock);
84   PassRegistryImpl *Impl = static_cast<PassRegistryImpl*>(getImpl());
85   PassRegistryImpl::MapType::const_iterator I = Impl->PassInfoMap.find(TI);
86   return I != Impl->PassInfoMap.end() ? I->second : nullptr;
87 }
88 
89 const PassInfo *PassRegistry::getPassInfo(StringRef Arg) const {
90   sys::SmartScopedReader<true> Guard(*Lock);
91   PassRegistryImpl *Impl = static_cast<PassRegistryImpl*>(getImpl());
92   PassRegistryImpl::StringMapType::const_iterator
93     I = Impl->PassInfoStringMap.find(Arg);
94   return I != Impl->PassInfoStringMap.end() ? I->second : nullptr;
95 }
96 
97 //===----------------------------------------------------------------------===//
98 // Pass Registration mechanism
99 //
100 
101 void PassRegistry::registerPass(const PassInfo &PI, bool ShouldFree) {
102   sys::SmartScopedWriter<true> Guard(*Lock);
103   PassRegistryImpl *Impl = static_cast<PassRegistryImpl*>(getImpl());
104   bool Inserted =
105     Impl->PassInfoMap.insert(std::make_pair(PI.getTypeInfo(),&PI)).second;
106   assert(Inserted && "Pass registered multiple times!");
107   (void)Inserted;
108   Impl->PassInfoStringMap[PI.getPassArgument()] = &PI;
109 
110   // Notify any listeners.
111   for (std::vector<PassRegistrationListener*>::iterator
112        I = Impl->Listeners.begin(), E = Impl->Listeners.end(); I != E; ++I)
113     (*I)->passRegistered(&PI);
114 
115   if (ShouldFree) Impl->ToFree.push_back(std::unique_ptr<const PassInfo>(&PI));
116 }
117 
118 void PassRegistry::unregisterPass(const PassInfo &PI) {
119   sys::SmartScopedWriter<true> Guard(*Lock);
120   PassRegistryImpl *Impl = static_cast<PassRegistryImpl*>(getImpl());
121   PassRegistryImpl::MapType::iterator I =
122     Impl->PassInfoMap.find(PI.getTypeInfo());
123   assert(I != Impl->PassInfoMap.end() && "Pass registered but not in map!");
124 
125   // Remove pass from the map.
126   Impl->PassInfoMap.erase(I);
127   Impl->PassInfoStringMap.erase(PI.getPassArgument());
128 }
129 
130 void PassRegistry::enumerateWith(PassRegistrationListener *L) {
131   sys::SmartScopedReader<true> Guard(*Lock);
132   PassRegistryImpl *Impl = static_cast<PassRegistryImpl*>(getImpl());
133   for (PassRegistryImpl::MapType::const_iterator I = Impl->PassInfoMap.begin(),
134        E = Impl->PassInfoMap.end(); I != E; ++I)
135     L->passEnumerate(I->second);
136 }
137 
138 
139 /// Analysis Group Mechanisms.
140 void PassRegistry::registerAnalysisGroup(const void *InterfaceID,
141                                          const void *PassID,
142                                          PassInfo& Registeree,
143                                          bool isDefault,
144                                          bool ShouldFree) {
145   PassInfo *InterfaceInfo =  const_cast<PassInfo*>(getPassInfo(InterfaceID));
146   if (!InterfaceInfo) {
147     // First reference to Interface, register it now.
148     registerPass(Registeree);
149     InterfaceInfo = &Registeree;
150   }
151   assert(Registeree.isAnalysisGroup() &&
152          "Trying to join an analysis group that is a normal pass!");
153 
154   if (PassID) {
155     PassInfo *ImplementationInfo = const_cast<PassInfo*>(getPassInfo(PassID));
156     assert(ImplementationInfo &&
157            "Must register pass before adding to AnalysisGroup!");
158 
159     sys::SmartScopedWriter<true> Guard(*Lock);
160 
161     // Make sure we keep track of the fact that the implementation implements
162     // the interface.
163     ImplementationInfo->addInterfaceImplemented(InterfaceInfo);
164 
165     PassRegistryImpl *Impl = static_cast<PassRegistryImpl*>(getImpl());
166     PassRegistryImpl::AnalysisGroupInfo &AGI =
167       Impl->AnalysisGroupInfoMap[InterfaceInfo];
168     assert(AGI.Implementations.count(ImplementationInfo) == 0 &&
169            "Cannot add a pass to the same analysis group more than once!");
170     AGI.Implementations.insert(ImplementationInfo);
171     if (isDefault) {
172       assert(InterfaceInfo->getNormalCtor() == nullptr &&
173              "Default implementation for analysis group already specified!");
174       assert(ImplementationInfo->getNormalCtor() &&
175            "Cannot specify pass as default if it does not have a default ctor");
176       InterfaceInfo->setNormalCtor(ImplementationInfo->getNormalCtor());
177       InterfaceInfo->setTargetMachineCtor(
178           ImplementationInfo->getTargetMachineCtor());
179     }
180   }
181 
182   PassRegistryImpl *Impl = static_cast<PassRegistryImpl*>(getImpl());
183   if (ShouldFree)
184     Impl->ToFree.push_back(std::unique_ptr<const PassInfo>(&Registeree));
185 }
186 
187 void PassRegistry::addRegistrationListener(PassRegistrationListener *L) {
188   sys::SmartScopedWriter<true> Guard(*Lock);
189   PassRegistryImpl *Impl = static_cast<PassRegistryImpl*>(getImpl());
190   Impl->Listeners.push_back(L);
191 }
192 
193 void PassRegistry::removeRegistrationListener(PassRegistrationListener *L) {
194   sys::SmartScopedWriter<true> Guard(*Lock);
195 
196   // NOTE: This is necessary, because removeRegistrationListener() can be called
197   // as part of the llvm_shutdown sequence.  Since we have no control over the
198   // order of that sequence, we need to gracefully handle the case where the
199   // PassRegistry is destructed before the object that triggers this call.
200   if (!pImpl) return;
201 
202   PassRegistryImpl *Impl = static_cast<PassRegistryImpl*>(getImpl());
203   std::vector<PassRegistrationListener*>::iterator I =
204     std::find(Impl->Listeners.begin(), Impl->Listeners.end(), L);
205   assert(I != Impl->Listeners.end() &&
206          "PassRegistrationListener not registered!");
207   Impl->Listeners.erase(I);
208 }
209