1 //===- PassManager.cpp - Infrastructure for managing & running IR passes --===//
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 #include "llvm/IR/PassManager.h"
10 #include "llvm/IR/PassManagerImpl.h"
11 #include <optional>
12 
13 using namespace llvm;
14 
15 namespace llvm {
16 // Explicit template instantiations and specialization defininitions for core
17 // template typedefs.
18 template class AllAnalysesOn<Module>;
19 template class AllAnalysesOn<Function>;
20 template class PassManager<Module>;
21 template class PassManager<Function>;
22 template class AnalysisManager<Module>;
23 template class AnalysisManager<Function>;
24 template class InnerAnalysisManagerProxy<FunctionAnalysisManager, Module>;
25 template class OuterAnalysisManagerProxy<ModuleAnalysisManager, Function>;
26 
27 template <>
28 bool FunctionAnalysisManagerModuleProxy::Result::invalidate(
29     Module &M, const PreservedAnalyses &PA,
30     ModuleAnalysisManager::Invalidator &Inv) {
31   // If literally everything is preserved, we're done.
32   if (PA.areAllPreserved())
33     return false; // This is still a valid proxy.
34 
35   // If this proxy isn't marked as preserved, then even if the result remains
36   // valid, the key itself may no longer be valid, so we clear everything.
37   //
38   // Note that in order to preserve this proxy, a module pass must ensure that
39   // the FAM has been completely updated to handle the deletion of functions.
40   // Specifically, any FAM-cached results for those functions need to have been
41   // forcibly cleared. When preserved, this proxy will only invalidate results
42   // cached on functions *still in the module* at the end of the module pass.
43   auto PAC = PA.getChecker<FunctionAnalysisManagerModuleProxy>();
44   if (!PAC.preserved() && !PAC.preservedSet<AllAnalysesOn<Module>>()) {
45     InnerAM->clear();
46     return true;
47   }
48 
49   // Directly check if the relevant set is preserved.
50   bool AreFunctionAnalysesPreserved =
51       PA.allAnalysesInSetPreserved<AllAnalysesOn<Function>>();
52 
53   // Now walk all the functions to see if any inner analysis invalidation is
54   // necessary.
55   for (Function &F : M) {
56     std::optional<PreservedAnalyses> FunctionPA;
57 
58     // Check to see whether the preserved set needs to be pruned based on
59     // module-level analysis invalidation that triggers deferred invalidation
60     // registered with the outer analysis manager proxy for this function.
61     if (auto *OuterProxy =
62             InnerAM->getCachedResult<ModuleAnalysisManagerFunctionProxy>(F))
63       for (const auto &OuterInvalidationPair :
64            OuterProxy->getOuterInvalidations()) {
65         AnalysisKey *OuterAnalysisID = OuterInvalidationPair.first;
66         const auto &InnerAnalysisIDs = OuterInvalidationPair.second;
67         if (Inv.invalidate(OuterAnalysisID, M, PA)) {
68           if (!FunctionPA)
69             FunctionPA = PA;
70           for (AnalysisKey *InnerAnalysisID : InnerAnalysisIDs)
71             FunctionPA->abandon(InnerAnalysisID);
72         }
73       }
74 
75     // Check if we needed a custom PA set, and if so we'll need to run the
76     // inner invalidation.
77     if (FunctionPA) {
78       InnerAM->invalidate(F, *FunctionPA);
79       continue;
80     }
81 
82     // Otherwise we only need to do invalidation if the original PA set didn't
83     // preserve all function analyses.
84     if (!AreFunctionAnalysesPreserved)
85       InnerAM->invalidate(F, PA);
86   }
87 
88   // Return false to indicate that this result is still a valid proxy.
89   return false;
90 }
91 } // namespace llvm
92 
93 void ModuleToFunctionPassAdaptor::printPipeline(
94     raw_ostream &OS, function_ref<StringRef(StringRef)> MapClassName2PassName) {
95   OS << "function";
96   if (EagerlyInvalidate)
97     OS << "<eager-inv>";
98   OS << '(';
99   Pass->printPipeline(OS, MapClassName2PassName);
100   OS << ')';
101 }
102 
103 PreservedAnalyses ModuleToFunctionPassAdaptor::run(Module &M,
104                                                    ModuleAnalysisManager &AM) {
105   FunctionAnalysisManager &FAM =
106       AM.getResult<FunctionAnalysisManagerModuleProxy>(M).getManager();
107 
108   // Request PassInstrumentation from analysis manager, will use it to run
109   // instrumenting callbacks for the passes later.
110   PassInstrumentation PI = AM.getResult<PassInstrumentationAnalysis>(M);
111 
112   PreservedAnalyses PA = PreservedAnalyses::all();
113   for (Function &F : M) {
114     if (F.isDeclaration())
115       continue;
116 
117     // Check the PassInstrumentation's BeforePass callbacks before running the
118     // pass, skip its execution completely if asked to (callback returns
119     // false).
120     if (!PI.runBeforePass<Function>(*Pass, F))
121       continue;
122 
123     PreservedAnalyses PassPA = Pass->run(F, FAM);
124 
125     // We know that the function pass couldn't have invalidated any other
126     // function's analyses (that's the contract of a function pass), so
127     // directly handle the function analysis manager's invalidation here.
128     FAM.invalidate(F, EagerlyInvalidate ? PreservedAnalyses::none() : PassPA);
129 
130     PI.runAfterPass(*Pass, F, PassPA);
131 
132     // Then intersect the preserved set so that invalidation of module
133     // analyses will eventually occur when the module pass completes.
134     PA.intersect(std::move(PassPA));
135   }
136 
137   // The FunctionAnalysisManagerModuleProxy is preserved because (we assume)
138   // the function passes we ran didn't add or remove any functions.
139   //
140   // We also preserve all analyses on Functions, because we did all the
141   // invalidation we needed to do above.
142   PA.preserveSet<AllAnalysesOn<Function>>();
143   PA.preserve<FunctionAnalysisManagerModuleProxy>();
144   return PA;
145 }
146 
147 AnalysisSetKey CFGAnalyses::SetKey;
148 
149 AnalysisSetKey PreservedAnalyses::AllAnalysesKey;
150