Pass.h revision c7d0f4be88cc7fa33d51736e0f53d3e00e69efb4
1//===- llvm/Pass.h - Base class for Passes ----------------------*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file was developed by the LLVM research group and is distributed under 6// the University of Illinois Open Source License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file defines a base class that indicates that a specified class is a 11// transformation pass implementation. 12// 13// Passes are designed this way so that it is possible to run passes in a cache 14// and organizationally optimal order without having to specify it at the front 15// end. This allows arbitrary passes to be strung together and have them 16// executed as effeciently as possible. 17// 18// Passes should extend one of the classes below, depending on the guarantees 19// that it can make about what will be modified as it is run. For example, most 20// global optimizations should derive from FunctionPass, because they do not add 21// or delete functions, they operate on the internals of the function. 22// 23// Note that this file #includes PassSupport.h and PassAnalysisSupport.h (at the 24// bottom), so the APIs exposed by these files are also automatically available 25// to all users of this file. 26// 27//===----------------------------------------------------------------------===// 28 29#ifndef LLVM_PASS_H 30#define LLVM_PASS_H 31 32#include "llvm/Support/Streams.h" 33#include <vector> 34#include <map> 35#include <iosfwd> 36#include <typeinfo> 37#include <cassert> 38 39#define USE_OLD_PASSMANAGER 1 40 41namespace llvm { 42 43class Value; 44class BasicBlock; 45class Function; 46class Module; 47class AnalysisUsage; 48class PassInfo; 49class ImmutablePass; 50template<class Trait> class PassManagerT; 51class BasicBlockPassManager; 52class FunctionPassManagerT; 53class ModulePassManager; 54struct AnalysisResolver; 55class AnalysisResolver_New; 56 57// AnalysisID - Use the PassInfo to identify a pass... 58typedef const PassInfo* AnalysisID; 59 60//===----------------------------------------------------------------------===// 61/// Pass interface - Implemented by all 'passes'. Subclass this if you are an 62/// interprocedural optimization or you do not fit into any of the more 63/// constrained passes described below. 64/// 65class Pass { 66 friend struct AnalysisResolver; 67 AnalysisResolver *Resolver; // AnalysisResolver this pass is owned by... 68 AnalysisResolver_New *Resolver_New; // Used to resolve analysis 69 const PassInfo *PassInfoCache; 70 71 // AnalysisImpls - This keeps track of which passes implement the interfaces 72 // that are required by the current pass (to implement getAnalysis()). 73 // 74 std::vector<std::pair<const PassInfo*, Pass*> > AnalysisImpls; 75 76 void operator=(const Pass&); // DO NOT IMPLEMENT 77 Pass(const Pass &); // DO NOT IMPLEMENT 78public: 79 Pass() : Resolver(0), Resolver_New(0), PassInfoCache(0) {} 80 virtual ~Pass() {} // Destructor is virtual so we can be subclassed 81 82 /// getPassName - Return a nice clean name for a pass. This usually 83 /// implemented in terms of the name that is registered by one of the 84 /// Registration templates, but can be overloaded directly, and if nothing 85 /// else is available, C++ RTTI will be consulted to get a SOMEWHAT 86 /// intelligible name for the pass. 87 /// 88 virtual const char *getPassName() const; 89 90 /// getPassInfo - Return the PassInfo data structure that corresponds to this 91 /// pass... If the pass has not been registered, this will return null. 92 /// 93 const PassInfo *getPassInfo() const; 94 95 /// runPass - Run this pass, returning true if a modification was made to the 96 /// module argument. This should be implemented by all concrete subclasses. 97 /// 98 virtual bool runPass(Module &M) { return false; } 99 virtual bool runPass(BasicBlock&) { return false; } 100 101 /// print - Print out the internal state of the pass. This is called by 102 /// Analyze to print out the contents of an analysis. Otherwise it is not 103 /// necessary to implement this method. Beware that the module pointer MAY be 104 /// null. This automatically forwards to a virtual function that does not 105 /// provide the Module* in case the analysis doesn't need it it can just be 106 /// ignored. 107 /// 108 virtual void print(std::ostream &O, const Module *M) const; 109 void print(std::ostream *O, const Module *M) const { if (O) print(*O, M); } 110 void dump() const; // dump - call print(std::cerr, 0); 111 112 // Access AnalysisResolver_New 113 inline void setResolver(AnalysisResolver_New *AR) { Resolver_New = AR; } 114 inline AnalysisResolver_New *getResolver() { return Resolver_New; } 115 116 /// getAnalysisUsage - This function should be overriden by passes that need 117 /// analysis information to do their job. If a pass specifies that it uses a 118 /// particular analysis result to this function, it can then use the 119 /// getAnalysis<AnalysisType>() function, below. 120 /// 121 virtual void getAnalysisUsage(AnalysisUsage &Info) const { 122 // By default, no analysis results are used, all are invalidated. 123 } 124 125 /// releaseMemory() - This member can be implemented by a pass if it wants to 126 /// be able to release its memory when it is no longer needed. The default 127 /// behavior of passes is to hold onto memory for the entire duration of their 128 /// lifetime (which is the entire compile time). For pipelined passes, this 129 /// is not a big deal because that memory gets recycled every time the pass is 130 /// invoked on another program unit. For IP passes, it is more important to 131 /// free memory when it is unused. 132 /// 133 /// Optionally implement this function to release pass memory when it is no 134 /// longer used. 135 /// 136 virtual void releaseMemory() {} 137 138 // dumpPassStructure - Implement the -debug-passes=PassStructure option 139 virtual void dumpPassStructure(unsigned Offset = 0); 140 141 142 // getPassInfo - Static method to get the pass information from a class name. 143 template<typename AnalysisClass> 144 static const PassInfo *getClassPassInfo() { 145 return lookupPassInfo(typeid(AnalysisClass)); 146 } 147 148 // lookupPassInfo - Return the pass info object for the specified pass class, 149 // or null if it is not known. 150 static const PassInfo *lookupPassInfo(const std::type_info &TI); 151 152 /// getAnalysisToUpdate<AnalysisType>() - This function is used by subclasses 153 /// to get to the analysis information that might be around that needs to be 154 /// updated. This is different than getAnalysis in that it can fail (ie the 155 /// analysis results haven't been computed), so should only be used if you 156 /// provide the capability to update an analysis that exists. This method is 157 /// often used by transformation APIs to update analysis results for a pass 158 /// automatically as the transform is performed. 159 /// 160 template<typename AnalysisType> 161 AnalysisType *getAnalysisToUpdate() const; // Defined in PassAnalysisSupport.h 162 163 /// mustPreserveAnalysisID - This method serves the same function as 164 /// getAnalysisToUpdate, but works if you just have an AnalysisID. This 165 /// obviously cannot give you a properly typed instance of the class if you 166 /// don't have the class name available (use getAnalysisToUpdate if you do), 167 /// but it can tell you if you need to preserve the pass at least. 168 /// 169 bool mustPreserveAnalysisID(const PassInfo *AnalysisID) const; 170 171 /// getAnalysis<AnalysisType>() - This function is used by subclasses to get 172 /// to the analysis information that they claim to use by overriding the 173 /// getAnalysisUsage function. 174 /// 175 template<typename AnalysisType> 176 AnalysisType &getAnalysis() const; // Defined in PassAnalysisSupport.h 177 178 template<typename AnalysisType> 179 AnalysisType &getAnalysisID(const PassInfo *PI) const; 180 181private: 182 template<typename Trait> friend class PassManagerT; 183 friend class ModulePassManager; 184 friend class FunctionPassManagerT; 185 friend class BasicBlockPassManager; 186}; 187 188inline std::ostream &operator<<(std::ostream &OS, const Pass &P) { 189 P.print(OS, 0); return OS; 190} 191 192//===----------------------------------------------------------------------===// 193/// ModulePass class - This class is used to implement unstructured 194/// interprocedural optimizations and analyses. ModulePasses may do anything 195/// they want to the program. 196/// 197class ModulePass : public Pass { 198public: 199 /// runOnModule - Virtual method overriden by subclasses to process the module 200 /// being operated on. 201 virtual bool runOnModule(Module &M) = 0; 202 203 virtual bool runPass(Module &M) { return runOnModule(M); } 204 virtual bool runPass(BasicBlock&) { return false; } 205 206#ifdef USE_OLD_PASSMANAGER 207 virtual void addToPassManager(ModulePassManager *PM, AnalysisUsage &AU); 208#else 209 // Force out-of-line virtual method. 210 virtual ~ModulePass(); 211#endif 212}; 213 214 215//===----------------------------------------------------------------------===// 216/// ImmutablePass class - This class is used to provide information that does 217/// not need to be run. This is useful for things like target information and 218/// "basic" versions of AnalysisGroups. 219/// 220class ImmutablePass : public ModulePass { 221public: 222 /// initializePass - This method may be overriden by immutable passes to allow 223 /// them to perform various initialization actions they require. This is 224 /// primarily because an ImmutablePass can "require" another ImmutablePass, 225 /// and if it does, the overloaded version of initializePass may get access to 226 /// these passes with getAnalysis<>. 227 /// 228 virtual void initializePass() {} 229 230 /// ImmutablePasses are never run. 231 /// 232 virtual bool runOnModule(Module &M) { return false; } 233 234#ifdef USE_OLD_PASSMANAGER 235private: 236 template<typename Trait> friend class PassManagerT; 237 friend class ModulePassManager; 238 virtual void addToPassManager(ModulePassManager *PM, AnalysisUsage &AU); 239#else 240 // Force out-of-line virtual method. 241 virtual ~ImmutablePass(); 242#endif 243}; 244 245//===----------------------------------------------------------------------===// 246/// FunctionPass class - This class is used to implement most global 247/// optimizations. Optimizations should subclass this class if they meet the 248/// following constraints: 249/// 250/// 1. Optimizations are organized globally, i.e., a function at a time 251/// 2. Optimizing a function does not cause the addition or removal of any 252/// functions in the module 253/// 254class FunctionPass : public ModulePass { 255public: 256 /// doInitialization - Virtual method overridden by subclasses to do 257 /// any necessary per-module initialization. 258 /// 259 virtual bool doInitialization(Module &M) { return false; } 260 261 /// runOnFunction - Virtual method overriden by subclasses to do the 262 /// per-function processing of the pass. 263 /// 264 virtual bool runOnFunction(Function &F) = 0; 265 266 /// doFinalization - Virtual method overriden by subclasses to do any post 267 /// processing needed after all passes have run. 268 /// 269 virtual bool doFinalization(Module &M) { return false; } 270 271 /// runOnModule - On a module, we run this pass by initializing, 272 /// ronOnFunction'ing once for every function in the module, then by 273 /// finalizing. 274 /// 275 virtual bool runOnModule(Module &M); 276 277 /// run - On a function, we simply initialize, run the function, then 278 /// finalize. 279 /// 280 bool run(Function &F); 281 282#ifdef USE_OLD_PASSMANAGER 283protected: 284 template<typename Trait> friend class PassManagerT; 285 friend class ModulePassManager; 286 friend class FunctionPassManagerT; 287 friend class BasicBlockPassManager; 288 virtual void addToPassManager(ModulePassManager *PM, AnalysisUsage &AU); 289 virtual void addToPassManager(FunctionPassManagerT *PM, AnalysisUsage &AU); 290#endif 291}; 292 293 294 295//===----------------------------------------------------------------------===// 296/// BasicBlockPass class - This class is used to implement most local 297/// optimizations. Optimizations should subclass this class if they 298/// meet the following constraints: 299/// 1. Optimizations are local, operating on either a basic block or 300/// instruction at a time. 301/// 2. Optimizations do not modify the CFG of the contained function, or any 302/// other basic block in the function. 303/// 3. Optimizations conform to all of the constraints of FunctionPasses. 304/// 305class BasicBlockPass : public FunctionPass { 306public: 307 /// doInitialization - Virtual method overridden by subclasses to do 308 /// any necessary per-module initialization. 309 /// 310 virtual bool doInitialization(Module &M) { return false; } 311 312 /// doInitialization - Virtual method overridden by BasicBlockPass subclasses 313 /// to do any necessary per-function initialization. 314 /// 315 virtual bool doInitialization(Function &F) { return false; } 316 317 /// runOnBasicBlock - Virtual method overriden by subclasses to do the 318 /// per-basicblock processing of the pass. 319 /// 320 virtual bool runOnBasicBlock(BasicBlock &BB) = 0; 321 322 /// doFinalization - Virtual method overriden by BasicBlockPass subclasses to 323 /// do any post processing needed after all passes have run. 324 /// 325 virtual bool doFinalization(Function &F) { return false; } 326 327 /// doFinalization - Virtual method overriden by subclasses to do any post 328 /// processing needed after all passes have run. 329 /// 330 virtual bool doFinalization(Module &M) { return false; } 331 332 333 // To run this pass on a function, we simply call runOnBasicBlock once for 334 // each function. 335 // 336 bool runOnFunction(Function &F); 337 338 /// To run directly on the basic block, we initialize, runOnBasicBlock, then 339 /// finalize. 340 /// 341 virtual bool runPass(Module &M) { return false; } 342 virtual bool runPass(BasicBlock &BB); 343 344#ifdef USE_OLD_PASSMANAGER 345private: 346 template<typename Trait> friend class PassManagerT; 347 friend class FunctionPassManagerT; 348 friend class BasicBlockPassManager; 349 virtual void addToPassManager(ModulePassManager *PM, AnalysisUsage &AU) { 350 FunctionPass::addToPassManager(PM, AU); 351 } 352 virtual void addToPassManager(FunctionPassManagerT *PM, AnalysisUsage &AU); 353 virtual void addToPassManager(BasicBlockPassManager *PM,AnalysisUsage &AU); 354#endif 355}; 356 357/// If the user specifies the -time-passes argument on an LLVM tool command line 358/// then the value of this boolean will be true, otherwise false. 359/// @brief This is the storage for the -time-passes option. 360extern bool TimePassesIsEnabled; 361 362} // End llvm namespace 363 364// Include support files that contain important APIs commonly used by Passes, 365// but that we want to separate out to make it easier to read the header files. 366// 367#include "llvm/PassSupport.h" 368#include "llvm/PassAnalysisSupport.h" 369 370#endif 371