1 //===- llvm/PassAnalysisSupport.h - Analysis Pass Support code --*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines stuff that is used to define and "use" Analysis Passes.
11 // This file is automatically #included by Pass.h, so:
13 // NO .CPP FILES SHOULD INCLUDE THIS FILE DIRECTLY
15 // Instead, #include Pass.h
17 //===----------------------------------------------------------------------===//
19 #ifndef LLVM_PASS_ANALYSIS_SUPPORT_H
20 #define LLVM_PASS_ANALYSIS_SUPPORT_H
26 // No need to include Pass.h, we are being included by it!
28 //===----------------------------------------------------------------------===//
29 // AnalysisUsage - Represent the analysis usage information of a pass. This
30 // tracks analyses that the pass REQUIRES (must be available when the pass
31 // runs), REQUIRES TRANSITIVE (must be available throughout the lifetime of the
32 // pass), and analyses that the pass PRESERVES (the pass does not invalidate the
33 // results of these analyses). This information is provided by a pass to the
34 // Pass infrastructure through the getAnalysisUsage virtual function.
37 // Sets of analyses required and preserved by a pass
38 std::vector<AnalysisID> Required, RequiredTransitive, Preserved;
41 AnalysisUsage() : PreservesAll(false) {}
43 // addRequired - Add the specified ID to the required set of the usage info
46 AnalysisUsage &addRequiredID(AnalysisID ID) {
47 assert(ID && "Pass class not registered!");
48 Required.push_back(ID);
51 template<class PassClass>
52 AnalysisUsage &addRequired() {
53 return addRequiredID(Pass::getClassPassInfo<PassClass>());
56 AnalysisUsage &addRequiredTransitiveID(AnalysisID ID) {
57 assert(ID && "Pass class not registered!");
58 Required.push_back(ID);
59 RequiredTransitive.push_back(ID);
62 template<class PassClass>
63 AnalysisUsage &addRequiredTransitive() {
64 AnalysisID ID = Pass::getClassPassInfo<PassClass>();
65 return addRequiredTransitiveID(ID);
68 // addPreserved - Add the specified ID to the set of analyses preserved by
71 AnalysisUsage &addPreservedID(AnalysisID ID) {
72 Preserved.push_back(ID);
76 template<class PassClass>
77 AnalysisUsage &addPreserved() {
78 assert(Pass::getClassPassInfo<PassClass>() && "Pass class not registered!");
79 Preserved.push_back(Pass::getClassPassInfo<PassClass>());
83 // setPreservesAll - Set by analyses that do not transform their input at all
84 void setPreservesAll() { PreservesAll = true; }
85 bool getPreservesAll() const { return PreservesAll; }
87 /// setPreservesCFG - This function should be called by the pass, iff they do
90 /// 1. Add or remove basic blocks from the function
91 /// 2. Modify terminator instructions in any way.
93 /// This function annotates the AnalysisUsage info object to say that analyses
94 /// that only depend on the CFG are preserved by this pass.
96 void setPreservesCFG();
98 const std::vector<AnalysisID> &getRequiredSet() const { return Required; }
99 const std::vector<AnalysisID> &getRequiredTransitiveSet() const {
100 return RequiredTransitive;
102 const std::vector<AnalysisID> &getPreservedSet() const { return Preserved; }
105 //===----------------------------------------------------------------------===//
106 // AnalysisResolver - Simple interface used by Pass objects to pull all
107 // analysis information out of pass manager that is responsible to manage
111 class AnalysisResolver {
113 AnalysisResolver(); // DO NOT IMPLEMENT
116 explicit AnalysisResolver(PMDataManager &P) : PM(P) { }
118 inline PMDataManager &getPMDataManager() { return PM; }
120 // Find pass that is implementing PI.
121 Pass *findImplPass(const PassInfo *PI) {
122 Pass *ResultPass = 0;
123 for (unsigned i = 0; i < AnalysisImpls.size() ; ++i) {
124 if (AnalysisImpls[i].first == PI) {
125 ResultPass = AnalysisImpls[i].second;
132 // Find pass that is implementing PI. Initialize pass for Function F.
133 Pass *findImplPass(Pass *P, const PassInfo *PI, Function &F);
135 void addAnalysisImplsPair(const PassInfo *PI, Pass *P) {
136 std::pair<const PassInfo*, Pass*> pir = std::make_pair(PI,P);
137 AnalysisImpls.push_back(pir);
140 // getAnalysisToUpdate - Return an analysis result or null if it doesn't exist
141 Pass *getAnalysisToUpdate(AnalysisID ID, bool Direction) const;
143 // AnalysisImpls - This keeps track of which passes implements the interfaces
144 // that are required by the current pass (to implement getAnalysis()).
145 // NOTE : Remove AnalysisImpls from class Pass, when AnalysisResolver
146 // replaces AnalysisResolver
147 std::vector<std::pair<const PassInfo*, Pass*> > AnalysisImpls;
150 // PassManager that is used to resolve analysis info
154 /// getAnalysisToUpdate<AnalysisType>() - This function is used by subclasses
155 /// to get to the analysis information that might be around that needs to be
156 /// updated. This is different than getAnalysis in that it can fail (ie the
157 /// analysis results haven't been computed), so should only be used if you
158 /// provide the capability to update an analysis that exists. This method is
159 /// often used by transformation APIs to update analysis results for a pass
160 /// automatically as the transform is performed.
162 template<typename AnalysisType>
163 AnalysisType *Pass::getAnalysisToUpdate() const {
164 assert(Resolver && "Pass not resident in a PassManager object!");
166 const PassInfo *PI = getClassPassInfo<AnalysisType>();
167 if (PI == 0) return 0;
168 return dynamic_cast<AnalysisType*>
169 (Resolver->getAnalysisToUpdate(PI, true));
172 /// getAnalysis<AnalysisType>() - This function is used by subclasses to get
173 /// to the analysis information that they claim to use by overriding the
174 /// getAnalysisUsage function.
176 template<typename AnalysisType>
177 AnalysisType &Pass::getAnalysis() const {
178 assert(Resolver &&"Pass has not been inserted into a PassManager object!");
180 return getAnalysisID<AnalysisType>(getClassPassInfo<AnalysisType>());
183 template<typename AnalysisType>
184 AnalysisType &Pass::getAnalysisID(const PassInfo *PI) const {
185 assert(PI && "getAnalysis for unregistered pass!");
186 assert(Resolver&&"Pass has not been inserted into a PassManager object!");
187 // PI *must* appear in AnalysisImpls. Because the number of passes used
188 // should be a small number, we just do a linear search over a (dense)
190 Pass *ResultPass = Resolver->findImplPass(PI);
191 assert (ResultPass &&
192 "getAnalysis*() called on an analysis that was not "
193 "'required' by pass!");
195 // Because the AnalysisType may not be a subclass of pass (for
196 // AnalysisGroups), we must use dynamic_cast here to potentially adjust the
197 // return pointer (because the class may multiply inherit, once from pass,
198 // once from AnalysisType).
200 AnalysisType *Result = dynamic_cast<AnalysisType*>(ResultPass);
201 assert(Result && "Pass does not implement interface required!");
205 /// getAnalysis<AnalysisType>() - This function is used by subclasses to get
206 /// to the analysis information that they claim to use by overriding the
207 /// getAnalysisUsage function.
209 template<typename AnalysisType>
210 AnalysisType &Pass::getAnalysis(Function &F) {
211 assert(Resolver &&"Pass has not been inserted into a PassManager object!");
213 return getAnalysisID<AnalysisType>(getClassPassInfo<AnalysisType>(), F);
216 template<typename AnalysisType>
217 AnalysisType &Pass::getAnalysisID(const PassInfo *PI, Function &F) {
218 assert(PI && "getAnalysis for unregistered pass!");
219 assert(Resolver&&"Pass has not been inserted into a PassManager object!");
220 // PI *must* appear in AnalysisImpls. Because the number of passes used
221 // should be a small number, we just do a linear search over a (dense)
223 Pass *ResultPass = Resolver->findImplPass(this, PI, F);
224 assert (ResultPass &&
225 "getAnalysis*() called on an analysis that was not "
226 "'required' by pass!");
228 // Because the AnalysisType may not be a subclass of pass (for
229 // AnalysisGroups), we must use dynamic_cast here to potentially adjust the
230 // return pointer (because the class may multiply inherit, once from pass,
231 // once from AnalysisType).
233 AnalysisType *Result = dynamic_cast<AnalysisType*>(ResultPass);
234 assert(Result && "Pass does not implement interface required!");
238 } // End llvm namespace