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   return PassInfoMap.lookup(TI);
44 }
45 
46 const PassInfo *PassRegistry::getPassInfo(StringRef Arg) const {
47   sys::SmartScopedReader<true> Guard(Lock);
48   return PassInfoStringMap.lookup(Arg);
49 }
50 
51 //===----------------------------------------------------------------------===//
52 // Pass Registration mechanism
53 //
54 
55 void PassRegistry::registerPass(const PassInfo &PI, bool ShouldFree) {
56   sys::SmartScopedWriter<true> Guard(Lock);
57   bool Inserted =
58       PassInfoMap.insert(std::make_pair(PI.getTypeInfo(), &PI)).second;
59   assert(Inserted && "Pass registered multiple times!");
60   (void)Inserted;
61   PassInfoStringMap[PI.getPassArgument()] = &PI;
62 
63   // Notify any listeners.
64   for (auto *Listener : Listeners)
65     Listener->passRegistered(&PI);
66 
67   if (ShouldFree)
68     ToFree.push_back(std::unique_ptr<const PassInfo>(&PI));
69 }
70 
71 void PassRegistry::enumerateWith(PassRegistrationListener *L) {
72   sys::SmartScopedReader<true> Guard(Lock);
73   for (auto PassInfoPair : PassInfoMap)
74     L->passEnumerate(PassInfoPair.second);
75 }
76 
77 /// Analysis Group Mechanisms.
78 void PassRegistry::registerAnalysisGroup(const void *InterfaceID,
79                                          const void *PassID,
80                                          PassInfo &Registeree, bool isDefault,
81                                          bool ShouldFree) {
82   PassInfo *InterfaceInfo = const_cast<PassInfo *>(getPassInfo(InterfaceID));
83   if (!InterfaceInfo) {
84     // First reference to Interface, register it now.
85     registerPass(Registeree);
86     InterfaceInfo = &Registeree;
87   }
88   assert(Registeree.isAnalysisGroup() &&
89          "Trying to join an analysis group that is a normal pass!");
90 
91   if (PassID) {
92     PassInfo *ImplementationInfo = const_cast<PassInfo *>(getPassInfo(PassID));
93     assert(ImplementationInfo &&
94            "Must register pass before adding to AnalysisGroup!");
95 
96     sys::SmartScopedWriter<true> Guard(Lock);
97 
98     // Make sure we keep track of the fact that the implementation implements
99     // the interface.
100     ImplementationInfo->addInterfaceImplemented(InterfaceInfo);
101 
102     if (isDefault) {
103       assert(InterfaceInfo->getNormalCtor() == nullptr &&
104              "Default implementation for analysis group already specified!");
105       assert(
106           ImplementationInfo->getNormalCtor() &&
107           "Cannot specify pass as default if it does not have a default ctor");
108       InterfaceInfo->setNormalCtor(ImplementationInfo->getNormalCtor());
109     }
110   }
111 
112   if (ShouldFree)
113     ToFree.push_back(std::unique_ptr<const PassInfo>(&Registeree));
114 }
115 
116 void PassRegistry::addRegistrationListener(PassRegistrationListener *L) {
117   sys::SmartScopedWriter<true> Guard(Lock);
118   Listeners.push_back(L);
119 }
120 
121 void PassRegistry::removeRegistrationListener(PassRegistrationListener *L) {
122   sys::SmartScopedWriter<true> Guard(Lock);
123 
124   auto I = llvm::find(Listeners, L);
125   Listeners.erase(I);
126 }
127