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
22 #include "llvm/Pass.h"
23 #include "llvm/ADT/SmallVector.h"
24 #include "llvm/ADT/StringRef.h"
29 //===----------------------------------------------------------------------===//
30 // AnalysisUsage - Represent the analysis usage information of a pass. This
31 // tracks analyses that the pass REQUIRES (must be available when the pass
32 // runs), REQUIRES TRANSITIVE (must be available throughout the lifetime of the
33 // pass), and analyses that the pass PRESERVES (the pass does not invalidate the
34 // results of these analyses). This information is provided by a pass to the
35 // Pass infrastructure through the getAnalysisUsage virtual function.
39 typedef SmallVector<AnalysisID, 32> VectorType;
42 // Sets of analyses required and preserved by a pass
43 VectorType Required, RequiredTransitive, Preserved;
47 AnalysisUsage() : PreservesAll(false) {}
49 // addRequired - Add the specified ID to the required set of the usage info
52 AnalysisUsage &addRequiredID(AnalysisID ID) {
53 assert(ID && "Pass class not registered!");
54 Required.push_back(ID);
57 template<class PassClass>
58 AnalysisUsage &addRequired() {
59 return addRequiredID(Pass::getClassPassInfo<PassClass>());
62 AnalysisUsage &addRequiredTransitiveID(AnalysisID ID) {
63 assert(ID && "Pass class not registered!");
64 Required.push_back(ID);
65 RequiredTransitive.push_back(ID);
68 template<class PassClass>
69 AnalysisUsage &addRequiredTransitive() {
70 AnalysisID ID = Pass::getClassPassInfo<PassClass>();
71 return addRequiredTransitiveID(ID);
74 // addPreserved - Add the specified ID to the set of analyses preserved by
77 AnalysisUsage &addPreservedID(AnalysisID ID) {
78 Preserved.push_back(ID);
82 // addPreserved - Add the specified Pass class to the set of analyses
83 // preserved by this pass.
85 template<class PassClass>
86 AnalysisUsage &addPreserved() {
87 assert(Pass::getClassPassInfo<PassClass>() && "Pass class not registered!");
88 Preserved.push_back(Pass::getClassPassInfo<PassClass>());
92 // addPreserved - Add the Pass with the specified argument string to the set
93 // of analyses preserved by this pass. If no such Pass exists, do nothing.
94 // This can be useful when a pass is trivially preserved, but may not be
95 // linked in. Be careful about spelling!
97 AnalysisUsage &addPreserved(StringRef Arg) {
98 const PassInfo *PI = Pass::lookupPassInfo(Arg);
99 // If the pass exists, preserve it. Otherwise silently do nothing.
100 if (PI) Preserved.push_back(PI);
104 // setPreservesAll - Set by analyses that do not transform their input at all
105 void setPreservesAll() { PreservesAll = true; }
106 bool getPreservesAll() const { return PreservesAll; }
108 /// setPreservesCFG - This function should be called by the pass, iff they do
111 /// 1. Add or remove basic blocks from the function
112 /// 2. Modify terminator instructions in any way.
114 /// This function annotates the AnalysisUsage info object to say that analyses
115 /// that only depend on the CFG are preserved by this pass.
117 void setPreservesCFG();
119 const VectorType &getRequiredSet() const { return Required; }
120 const VectorType &getRequiredTransitiveSet() const {
121 return RequiredTransitive;
123 const VectorType &getPreservedSet() const { return Preserved; }
126 //===----------------------------------------------------------------------===//
127 // AnalysisResolver - Simple interface used by Pass objects to pull all
128 // analysis information out of pass manager that is responsible to manage
132 class AnalysisResolver {
134 AnalysisResolver(); // DO NOT IMPLEMENT
137 explicit AnalysisResolver(PMDataManager &P) : PM(P) { }
139 inline PMDataManager &getPMDataManager() { return PM; }
141 // Find pass that is implementing PI.
142 Pass *findImplPass(const PassInfo *PI) {
143 Pass *ResultPass = 0;
144 for (unsigned i = 0; i < AnalysisImpls.size() ; ++i) {
145 if (AnalysisImpls[i].first == PI) {
146 ResultPass = AnalysisImpls[i].second;
153 // Find pass that is implementing PI. Initialize pass for Function F.
154 Pass *findImplPass(Pass *P, const PassInfo *PI, Function &F);
156 void addAnalysisImplsPair(const PassInfo *PI, Pass *P) {
157 std::pair<const PassInfo*, Pass*> pir = std::make_pair(PI,P);
158 AnalysisImpls.push_back(pir);
161 /// clearAnalysisImpls - Clear cache that is used to connect a pass to the
162 /// the analysis (PassInfo).
163 void clearAnalysisImpls() {
164 AnalysisImpls.clear();
167 // getAnalysisIfAvailable - Return analysis result or null if it doesn't exist
168 Pass *getAnalysisIfAvailable(AnalysisID ID, bool Direction) const;
170 // AnalysisImpls - This keeps track of which passes implements the interfaces
171 // that are required by the current pass (to implement getAnalysis()).
172 std::vector<std::pair<const PassInfo*, Pass*> > AnalysisImpls;
175 // PassManager that is used to resolve analysis info
179 /// getAnalysisIfAvailable<AnalysisType>() - Subclasses use this function to
180 /// get analysis information that might be around, for example to update it.
181 /// This is different than getAnalysis in that it can fail (if the analysis
182 /// results haven't been computed), so should only be used if you can handle
183 /// the case when the analysis is not available. This method is often used by
184 /// transformation APIs to update analysis results for a pass automatically as
185 /// the transform is performed.
187 template<typename AnalysisType>
188 AnalysisType *Pass::getAnalysisIfAvailable() const {
189 assert(Resolver && "Pass not resident in a PassManager object!");
191 const PassInfo *PI = getClassPassInfo<AnalysisType>();
192 if (PI == 0) return 0;
194 Pass *ResultPass = Resolver->getAnalysisIfAvailable(PI, true);
195 if (ResultPass == 0) return 0;
197 // Because the AnalysisType may not be a subclass of pass (for
198 // AnalysisGroups), we use getAdjustedAnalysisPointer here to potentially
199 // adjust the return pointer (because the class may multiply inherit, once
200 // from pass, once from AnalysisType).
201 return (AnalysisType*)ResultPass->getAdjustedAnalysisPointer(PI);
204 /// getAnalysis<AnalysisType>() - This function is used by subclasses to get
205 /// to the analysis information that they claim to use by overriding the
206 /// getAnalysisUsage function.
208 template<typename AnalysisType>
209 AnalysisType &Pass::getAnalysis() const {
210 assert(Resolver && "Pass has not been inserted into a PassManager object!");
211 return getAnalysisID<AnalysisType>(getClassPassInfo<AnalysisType>());
214 template<typename AnalysisType>
215 AnalysisType &Pass::getAnalysisID(const PassInfo *PI) const {
216 assert(PI && "getAnalysis for unregistered pass!");
217 assert(Resolver&&"Pass has not been inserted into a PassManager object!");
218 // PI *must* appear in AnalysisImpls. Because the number of passes used
219 // should be a small number, we just do a linear search over a (dense)
221 Pass *ResultPass = Resolver->findImplPass(PI);
222 assert (ResultPass &&
223 "getAnalysis*() called on an analysis that was not "
224 "'required' by pass!");
226 // Because the AnalysisType may not be a subclass of pass (for
227 // AnalysisGroups), we use getAdjustedAnalysisPointer here to potentially
228 // adjust the return pointer (because the class may multiply inherit, once
229 // from pass, once from AnalysisType).
230 return *(AnalysisType*)ResultPass->getAdjustedAnalysisPointer(PI);
233 /// getAnalysis<AnalysisType>() - This function is used by subclasses to get
234 /// to the analysis information that they claim to use by overriding the
235 /// getAnalysisUsage function.
237 template<typename AnalysisType>
238 AnalysisType &Pass::getAnalysis(Function &F) {
239 assert(Resolver &&"Pass has not been inserted into a PassManager object!");
241 return getAnalysisID<AnalysisType>(getClassPassInfo<AnalysisType>(), F);
244 template<typename AnalysisType>
245 AnalysisType &Pass::getAnalysisID(const PassInfo *PI, Function &F) {
246 assert(PI && "getAnalysis for unregistered pass!");
247 assert(Resolver && "Pass has not been inserted into a PassManager object!");
248 // PI *must* appear in AnalysisImpls. Because the number of passes used
249 // should be a small number, we just do a linear search over a (dense)
251 Pass *ResultPass = Resolver->findImplPass(this, PI, F);
252 assert(ResultPass && "Unable to find requested analysis info");
254 // Because the AnalysisType may not be a subclass of pass (for
255 // AnalysisGroups), we use getAdjustedAnalysisPointer here to potentially
256 // adjust the return pointer (because the class may multiply inherit, once
257 // from pass, once from AnalysisType).
258 return *(AnalysisType*)ResultPass->getAdjustedAnalysisPointer(PI);
261 } // End llvm namespace