1 //===- llvm/PassAnalysisSupport.h - Analysis Pass Support code --*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This file defines stuff that is used to define and "use" Analysis Passes. 11 // This file is automatically #included by Pass.h, so: 12 // 13 // NO .CPP FILES SHOULD INCLUDE THIS FILE DIRECTLY 14 // 15 // Instead, #include Pass.h 16 // 17 //===----------------------------------------------------------------------===// 18 19 #ifndef LLVM_PASS_ANALYSIS_SUPPORT_H 20 #define LLVM_PASS_ANALYSIS_SUPPORT_H 21 22 #include "llvm/ADT/SmallVector.h" 23 #include "llvm/ADT/StringRef.h" 24 #include <vector> 25 26 namespace llvm { 27 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. 35 // 36 class AnalysisUsage { 37 public: 38 typedef SmallVector<AnalysisID, 32> VectorType; 39 40 private: 41 // Sets of analyses required and preserved by a pass 42 VectorType Required, RequiredTransitive, Preserved; 43 bool PreservesAll; 44 45 public: 46 AnalysisUsage() : PreservesAll(false) {} 47 48 // addRequired - Add the specified ID to the required set of the usage info 49 // for a pass. 50 // 51 AnalysisUsage &addRequiredID(const void *ID); 52 AnalysisUsage &addRequiredID(char &ID); 53 template<class PassClass> 54 AnalysisUsage &addRequired() { 55 return addRequiredID(PassClass::ID); 56 } 57 58 AnalysisUsage &addRequiredTransitiveID(char &ID); 59 template<class PassClass> 60 AnalysisUsage &addRequiredTransitive() { 61 return addRequiredTransitiveID(PassClass::ID); 62 } 63 64 // addPreserved - Add the specified ID to the set of analyses preserved by 65 // this pass 66 // 67 AnalysisUsage &addPreservedID(const void *ID) { 68 Preserved.push_back(ID); 69 return *this; 70 } 71 AnalysisUsage &addPreservedID(char &ID) { 72 Preserved.push_back(&ID); 73 return *this; 74 } 75 76 // addPreserved - Add the specified Pass class to the set of analyses 77 // preserved by this pass. 78 // 79 template<class PassClass> 80 AnalysisUsage &addPreserved() { 81 Preserved.push_back(&PassClass::ID); 82 return *this; 83 } 84 85 // addPreserved - Add the Pass with the specified argument string to the set 86 // of analyses preserved by this pass. If no such Pass exists, do nothing. 87 // This can be useful when a pass is trivially preserved, but may not be 88 // linked in. Be careful about spelling! 89 // 90 AnalysisUsage &addPreserved(StringRef Arg); 91 92 // setPreservesAll - Set by analyses that do not transform their input at all 93 void setPreservesAll() { PreservesAll = true; } 94 bool getPreservesAll() const { return PreservesAll; } 95 96 /// setPreservesCFG - This function should be called by the pass, iff they do 97 /// not: 98 /// 99 /// 1. Add or remove basic blocks from the function 100 /// 2. Modify terminator instructions in any way. 101 /// 102 /// This function annotates the AnalysisUsage info object to say that analyses 103 /// that only depend on the CFG are preserved by this pass. 104 /// 105 void setPreservesCFG(); 106 107 const VectorType &getRequiredSet() const { return Required; } 108 const VectorType &getRequiredTransitiveSet() const { 109 return RequiredTransitive; 110 } 111 const VectorType &getPreservedSet() const { return Preserved; } 112 }; 113 114 //===----------------------------------------------------------------------===// 115 // AnalysisResolver - Simple interface used by Pass objects to pull all 116 // analysis information out of pass manager that is responsible to manage 117 // the pass. 118 // 119 class PMDataManager; 120 class AnalysisResolver { 121 private: 122 AnalysisResolver(); // DO NOT IMPLEMENT 123 124 public: 125 explicit AnalysisResolver(PMDataManager &P) : PM(P) { } 126 127 inline PMDataManager &getPMDataManager() { return PM; } 128 129 // Find pass that is implementing PI. 130 Pass *findImplPass(AnalysisID PI) { 131 Pass *ResultPass = 0; 132 for (unsigned i = 0; i < AnalysisImpls.size() ; ++i) { 133 if (AnalysisImpls[i].first == PI) { 134 ResultPass = AnalysisImpls[i].second; 135 break; 136 } 137 } 138 return ResultPass; 139 } 140 141 // Find pass that is implementing PI. Initialize pass for Function F. 142 Pass *findImplPass(Pass *P, AnalysisID PI, Function &F); 143 144 void addAnalysisImplsPair(AnalysisID PI, Pass *P) { 145 if (findImplPass(PI) == P) 146 return; 147 std::pair<AnalysisID, Pass*> pir = std::make_pair(PI,P); 148 AnalysisImpls.push_back(pir); 149 } 150 151 /// clearAnalysisImpls - Clear cache that is used to connect a pass to the 152 /// the analysis (PassInfo). 153 void clearAnalysisImpls() { 154 AnalysisImpls.clear(); 155 } 156 157 // getAnalysisIfAvailable - Return analysis result or null if it doesn't exist 158 Pass *getAnalysisIfAvailable(AnalysisID ID, bool Direction) const; 159 160 private: 161 // AnalysisImpls - This keeps track of which passes implements the interfaces 162 // that are required by the current pass (to implement getAnalysis()). 163 std::vector<std::pair<AnalysisID, Pass*> > AnalysisImpls; 164 165 // PassManager that is used to resolve analysis info 166 PMDataManager &PM; 167 }; 168 169 /// getAnalysisIfAvailable<AnalysisType>() - Subclasses use this function to 170 /// get analysis information that might be around, for example to update it. 171 /// This is different than getAnalysis in that it can fail (if the analysis 172 /// results haven't been computed), so should only be used if you can handle 173 /// the case when the analysis is not available. This method is often used by 174 /// transformation APIs to update analysis results for a pass automatically as 175 /// the transform is performed. 176 /// 177 template<typename AnalysisType> 178 AnalysisType *Pass::getAnalysisIfAvailable() const { 179 assert(Resolver && "Pass not resident in a PassManager object!"); 180 181 const void *PI = &AnalysisType::ID; 182 183 Pass *ResultPass = Resolver->getAnalysisIfAvailable(PI, true); 184 if (ResultPass == 0) return 0; 185 186 // Because the AnalysisType may not be a subclass of pass (for 187 // AnalysisGroups), we use getAdjustedAnalysisPointer here to potentially 188 // adjust the return pointer (because the class may multiply inherit, once 189 // from pass, once from AnalysisType). 190 return (AnalysisType*)ResultPass->getAdjustedAnalysisPointer(PI); 191 } 192 193 /// getAnalysis<AnalysisType>() - This function is used by subclasses to get 194 /// to the analysis information that they claim to use by overriding the 195 /// getAnalysisUsage function. 196 /// 197 template<typename AnalysisType> 198 AnalysisType &Pass::getAnalysis() const { 199 assert(Resolver && "Pass has not been inserted into a PassManager object!"); 200 return getAnalysisID<AnalysisType>(&AnalysisType::ID); 201 } 202 203 template<typename AnalysisType> 204 AnalysisType &Pass::getAnalysisID(AnalysisID PI) const { 205 assert(PI && "getAnalysis for unregistered pass!"); 206 assert(Resolver&&"Pass has not been inserted into a PassManager object!"); 207 // PI *must* appear in AnalysisImpls. Because the number of passes used 208 // should be a small number, we just do a linear search over a (dense) 209 // vector. 210 Pass *ResultPass = Resolver->findImplPass(PI); 211 assert (ResultPass && 212 "getAnalysis*() called on an analysis that was not " 213 "'required' by pass!"); 214 215 // Because the AnalysisType may not be a subclass of pass (for 216 // AnalysisGroups), we use getAdjustedAnalysisPointer here to potentially 217 // adjust the return pointer (because the class may multiply inherit, once 218 // from pass, once from AnalysisType). 219 return *(AnalysisType*)ResultPass->getAdjustedAnalysisPointer(PI); 220 } 221 222 /// getAnalysis<AnalysisType>() - This function is used by subclasses to get 223 /// to the analysis information that they claim to use by overriding the 224 /// getAnalysisUsage function. 225 /// 226 template<typename AnalysisType> 227 AnalysisType &Pass::getAnalysis(Function &F) { 228 assert(Resolver &&"Pass has not been inserted into a PassManager object!"); 229 230 return getAnalysisID<AnalysisType>(&AnalysisType::ID, F); 231 } 232 233 template<typename AnalysisType> 234 AnalysisType &Pass::getAnalysisID(AnalysisID PI, Function &F) { 235 assert(PI && "getAnalysis for unregistered pass!"); 236 assert(Resolver && "Pass has not been inserted into a PassManager object!"); 237 // PI *must* appear in AnalysisImpls. Because the number of passes used 238 // should be a small number, we just do a linear search over a (dense) 239 // vector. 240 Pass *ResultPass = Resolver->findImplPass(this, PI, F); 241 assert(ResultPass && "Unable to find requested analysis info"); 242 243 // Because the AnalysisType may not be a subclass of pass (for 244 // AnalysisGroups), we use getAdjustedAnalysisPointer here to potentially 245 // adjust the return pointer (because the class may multiply inherit, once 246 // from pass, once from AnalysisType). 247 return *(AnalysisType*)ResultPass->getAdjustedAnalysisPointer(PI); 248 } 249 250 } // End llvm namespace 251 252 #endif 253
