1 //===- PassRegistry.cpp - Pass Registration Implementation ----------------===//
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 PassRegistry, with which passes are registered on
10 // initialization, and supports the PassManager in dependency resolution.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "llvm/PassRegistry.h"
15 #include "llvm/ADT/STLExtras.h"
16 #include "llvm/Pass.h"
17 #include "llvm/PassInfo.h"
18 #include "llvm/Support/ManagedStatic.h"
19 #include <cassert>
20 #include <memory>
21 #include <utility>
22 
23 using namespace llvm;
24 
25 // FIXME: We use ManagedStatic to erase the pass registrar on shutdown.
26 // Unfortunately, passes are registered with static ctors, and having
27 // llvm_shutdown clear this map prevents successful resurrection after
28 // llvm_shutdown is run.  Ideally we should find a solution so that we don't
29 // leak the map, AND can still resurrect after shutdown.
30 static ManagedStatic<PassRegistry> PassRegistryObj;
31 PassRegistry *PassRegistry::getPassRegistry() {
32   return &*PassRegistryObj;
33 }
34 
35 //===----------------------------------------------------------------------===//
36 // Accessors
37 //
38 
39 PassRegistry::~PassRegistry() = default;
40 
41 const PassInfo *PassRegistry::getPassInfo(const void *TI) const {
42   sys::SmartScopedReader<true> Guard(Lock);
43   MapType::const_iterator I = PassInfoMap.find(TI);
44   return I != PassInfoMap.end() ? I->second : nullptr;
45 }
46 
47 const PassInfo *PassRegistry::getPassInfo(StringRef Arg) const {
48   sys::SmartScopedReader<true> Guard(Lock);
49   StringMapType::const_iterator I = PassInfoStringMap.find(Arg);
50   return I != PassInfoStringMap.end() ? I->second : nullptr;
51 }
52 
53 //===----------------------------------------------------------------------===//
54 // Pass Registration mechanism
55 //
56 
57 void PassRegistry::registerPass(const PassInfo &PI, bool ShouldFree) {
58   sys::SmartScopedWriter<true> Guard(Lock);
59   bool Inserted =
60       PassInfoMap.insert(std::make_pair(PI.getTypeInfo(), &PI)).second;
61   assert(Inserted && "Pass registered multiple times!");
62   (void)Inserted;
63   PassInfoStringMap[PI.getPassArgument()] = &PI;
64 
65   // Notify any listeners.
66   for (auto *Listener : Listeners)
67     Listener->passRegistered(&PI);
68 
69   if (ShouldFree)
70     ToFree.push_back(std::unique_ptr<const PassInfo>(&PI));
71 }
72 
73 void PassRegistry::enumerateWith(PassRegistrationListener *L) {
74   sys::SmartScopedReader<true> Guard(Lock);
75   for (auto PassInfoPair : PassInfoMap)
76     L->passEnumerate(PassInfoPair.second);
77 }
78 
79 /// Analysis Group Mechanisms.
80 void PassRegistry::registerAnalysisGroup(const void *InterfaceID,
81                                          const void *PassID,
82                                          PassInfo &Registeree, bool isDefault,
83                                          bool ShouldFree) {
84   PassInfo *InterfaceInfo = const_cast<PassInfo *>(getPassInfo(InterfaceID));
85   if (!InterfaceInfo) {
86     // First reference to Interface, register it now.
87     registerPass(Registeree);
88     InterfaceInfo = &Registeree;
89   }
90   assert(Registeree.isAnalysisGroup() &&
91          "Trying to join an analysis group that is a normal pass!");
92 
93   if (PassID) {
94     PassInfo *ImplementationInfo = const_cast<PassInfo *>(getPassInfo(PassID));
95     assert(ImplementationInfo &&
96            "Must register pass before adding to AnalysisGroup!");
97 
98     sys::SmartScopedWriter<true> Guard(Lock);
99 
100     // Make sure we keep track of the fact that the implementation implements
101     // the interface.
102     ImplementationInfo->addInterfaceImplemented(InterfaceInfo);
103 
104     if (isDefault) {
105       assert(InterfaceInfo->getNormalCtor() == nullptr &&
106              "Default implementation for analysis group already specified!");
107       assert(
108           ImplementationInfo->getNormalCtor() &&
109           "Cannot specify pass as default if it does not have a default ctor");
110       InterfaceInfo->setNormalCtor(ImplementationInfo->getNormalCtor());
111     }
112   }
113 
114   if (ShouldFree)
115     ToFree.push_back(std::unique_ptr<const PassInfo>(&Registeree));
116 }
117 
118 void PassRegistry::addRegistrationListener(PassRegistrationListener *L) {
119   sys::SmartScopedWriter<true> Guard(Lock);
120   Listeners.push_back(L);
121 }
122 
123 void PassRegistry::removeRegistrationListener(PassRegistrationListener *L) {
124   sys::SmartScopedWriter<true> Guard(Lock);
125 
126   auto I = llvm::find(Listeners, L);
127   Listeners.erase(I);
128 }
129