Pass.h revision 8688428b0510e5e7dab43379b3d53c9b40dc182d
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//Use new Pass Manager. Disable old Pass Manager. 40//#define USE_OLD_PASSMANAGER 1 41 42namespace llvm { 43 44class Value; 45class BasicBlock; 46class Function; 47class Module; 48class AnalysisUsage; 49class PassInfo; 50class ImmutablePass; 51template<class Trait> class PassManagerT; 52class BasicBlockPassManager; 53class FunctionPassManagerT; 54class ModulePassManager; 55struct AnalysisResolver; 56class AnalysisResolver_New; 57 58// AnalysisID - Use the PassInfo to identify a pass... 59typedef const PassInfo* AnalysisID; 60 61//===----------------------------------------------------------------------===// 62/// Pass interface - Implemented by all 'passes'. Subclass this if you are an 63/// interprocedural optimization or you do not fit into any of the more 64/// constrained passes described below. 65/// 66class Pass { 67 friend struct AnalysisResolver; 68 AnalysisResolver *Resolver; // AnalysisResolver this pass is owned by... 69 AnalysisResolver_New *Resolver_New; // Used to resolve analysis 70 const PassInfo *PassInfoCache; 71 72 // AnalysisImpls - This keeps track of which passes implement the interfaces 73 // that are required by the current pass (to implement getAnalysis()). 74 // 75 std::vector<std::pair<const PassInfo*, Pass*> > AnalysisImpls; 76 77 void operator=(const Pass&); // DO NOT IMPLEMENT 78 Pass(const Pass &); // DO NOT IMPLEMENT 79public: 80 Pass() : Resolver(0), Resolver_New(0), PassInfoCache(0) {} 81 virtual ~Pass() {} // Destructor is virtual so we can be subclassed 82 83 /// getPassName - Return a nice clean name for a pass. This usually 84 /// implemented in terms of the name that is registered by one of the 85 /// Registration templates, but can be overloaded directly, and if nothing 86 /// else is available, C++ RTTI will be consulted to get a SOMEWHAT 87 /// intelligible name for the pass. 88 /// 89 virtual const char *getPassName() const; 90 91 /// getPassInfo - Return the PassInfo data structure that corresponds to this 92 /// pass... If the pass has not been registered, this will return null. 93 /// 94 const PassInfo *getPassInfo() const; 95 96 /// runPass - Run this pass, returning true if a modification was made to the 97 /// module argument. This should be implemented by all concrete subclasses. 98 /// 99 virtual bool runPass(Module &M) { return false; } 100 virtual bool runPass(BasicBlock&) { return false; } 101 102 /// print - Print out the internal state of the pass. This is called by 103 /// Analyze to print out the contents of an analysis. Otherwise it is not 104 /// necessary to implement this method. Beware that the module pointer MAY be 105 /// null. This automatically forwards to a virtual function that does not 106 /// provide the Module* in case the analysis doesn't need it it can just be 107 /// ignored. 108 /// 109 virtual void print(std::ostream &O, const Module *M) const; 110 void print(std::ostream *O, const Module *M) const { if (O) print(*O, M); } 111 void dump() const; // dump - call print(std::cerr, 0); 112 113 // Access AnalysisResolver_New 114 inline void setResolver(AnalysisResolver_New *AR) { Resolver_New = AR; } 115 inline AnalysisResolver_New *getResolver() { return Resolver_New; } 116 117 /// getAnalysisUsage - This function should be overriden by passes that need 118 /// analysis information to do their job. If a pass specifies that it uses a 119 /// particular analysis result to this function, it can then use the 120 /// getAnalysis<AnalysisType>() function, below. 121 /// 122 virtual void getAnalysisUsage(AnalysisUsage &Info) const { 123 // By default, no analysis results are used, all are invalidated. 124 } 125 126 /// releaseMemory() - This member can be implemented by a pass if it wants to 127 /// be able to release its memory when it is no longer needed. The default 128 /// behavior of passes is to hold onto memory for the entire duration of their 129 /// lifetime (which is the entire compile time). For pipelined passes, this 130 /// is not a big deal because that memory gets recycled every time the pass is 131 /// invoked on another program unit. For IP passes, it is more important to 132 /// free memory when it is unused. 133 /// 134 /// Optionally implement this function to release pass memory when it is no 135 /// longer used. 136 /// 137 virtual void releaseMemory() {} 138 139 // dumpPassStructure - Implement the -debug-passes=PassStructure option 140 virtual void dumpPassStructure(unsigned Offset = 0); 141 142 143 // getPassInfo - Static method to get the pass information from a class name. 144 template<typename AnalysisClass> 145 static const PassInfo *getClassPassInfo() { 146 return lookupPassInfo(typeid(AnalysisClass)); 147 } 148 149 // lookupPassInfo - Return the pass info object for the specified pass class, 150 // or null if it is not known. 151 static const PassInfo *lookupPassInfo(const std::type_info &TI); 152 153 /// getAnalysisToUpdate<AnalysisType>() - This function is used by subclasses 154 /// to get to the analysis information that might be around that needs to be 155 /// updated. This is different than getAnalysis in that it can fail (ie the 156 /// analysis results haven't been computed), so should only be used if you 157 /// provide the capability to update an analysis that exists. This method is 158 /// often used by transformation APIs to update analysis results for a pass 159 /// automatically as the transform is performed. 160 /// 161 template<typename AnalysisType> 162 AnalysisType *getAnalysisToUpdate() const; // Defined in PassAnalysisSupport.h 163 164 /// mustPreserveAnalysisID - This method serves the same function as 165 /// getAnalysisToUpdate, but works if you just have an AnalysisID. This 166 /// obviously cannot give you a properly typed instance of the class if you 167 /// don't have the class name available (use getAnalysisToUpdate if you do), 168 /// but it can tell you if you need to preserve the pass at least. 169 /// 170 bool mustPreserveAnalysisID(const PassInfo *AnalysisID) const; 171 172 /// 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. 175 /// 176 template<typename AnalysisType> 177 AnalysisType &getAnalysis() const; // Defined in PassAnalysisSupport.h 178 179 template<typename AnalysisType> 180 AnalysisType &getAnalysisID(const PassInfo *PI) const; 181 182private: 183 template<typename Trait> friend class PassManagerT; 184 friend class ModulePassManager; 185 friend class FunctionPassManagerT; 186 friend class BasicBlockPassManager; 187}; 188 189inline std::ostream &operator<<(std::ostream &OS, const Pass &P) { 190 P.print(OS, 0); return OS; 191} 192 193//===----------------------------------------------------------------------===// 194/// ModulePass class - This class is used to implement unstructured 195/// interprocedural optimizations and analyses. ModulePasses may do anything 196/// they want to the program. 197/// 198class ModulePass : public Pass { 199public: 200 /// runOnModule - Virtual method overriden by subclasses to process the module 201 /// being operated on. 202 virtual bool runOnModule(Module &M) = 0; 203 204 virtual bool runPass(Module &M) { return runOnModule(M); } 205 virtual bool runPass(BasicBlock&) { return false; } 206 207#ifdef USE_OLD_PASSMANAGER 208 virtual void addToPassManager(ModulePassManager *PM, AnalysisUsage &AU); 209#else 210 // Force out-of-line virtual method. 211 virtual ~ModulePass(); 212#endif 213}; 214 215 216//===----------------------------------------------------------------------===// 217/// ImmutablePass class - This class is used to provide information that does 218/// not need to be run. This is useful for things like target information and 219/// "basic" versions of AnalysisGroups. 220/// 221class ImmutablePass : public ModulePass { 222public: 223 /// initializePass - This method may be overriden by immutable passes to allow 224 /// them to perform various initialization actions they require. This is 225 /// primarily because an ImmutablePass can "require" another ImmutablePass, 226 /// and if it does, the overloaded version of initializePass may get access to 227 /// these passes with getAnalysis<>. 228 /// 229 virtual void initializePass() {} 230 231 /// ImmutablePasses are never run. 232 /// 233 virtual bool runOnModule(Module &M) { return false; } 234 235#ifdef USE_OLD_PASSMANAGER 236private: 237 template<typename Trait> friend class PassManagerT; 238 friend class ModulePassManager; 239 virtual void addToPassManager(ModulePassManager *PM, AnalysisUsage &AU); 240#else 241 // Force out-of-line virtual method. 242 virtual ~ImmutablePass(); 243#endif 244}; 245 246//===----------------------------------------------------------------------===// 247/// FunctionPass class - This class is used to implement most global 248/// optimizations. Optimizations should subclass this class if they meet the 249/// following constraints: 250/// 251/// 1. Optimizations are organized globally, i.e., a function at a time 252/// 2. Optimizing a function does not cause the addition or removal of any 253/// functions in the module 254/// 255class FunctionPass : public ModulePass { 256public: 257 /// doInitialization - Virtual method overridden by subclasses to do 258 /// any necessary per-module initialization. 259 /// 260 virtual bool doInitialization(Module &M) { return false; } 261 262 /// runOnFunction - Virtual method overriden by subclasses to do the 263 /// per-function processing of the pass. 264 /// 265 virtual bool runOnFunction(Function &F) = 0; 266 267 /// doFinalization - Virtual method overriden by subclasses to do any post 268 /// processing needed after all passes have run. 269 /// 270 virtual bool doFinalization(Module &M) { return false; } 271 272 /// runOnModule - On a module, we run this pass by initializing, 273 /// ronOnFunction'ing once for every function in the module, then by 274 /// finalizing. 275 /// 276 virtual bool runOnModule(Module &M); 277 278 /// run - On a function, we simply initialize, run the function, then 279 /// finalize. 280 /// 281 bool run(Function &F); 282 283#ifdef USE_OLD_PASSMANAGER 284protected: 285 template<typename Trait> friend class PassManagerT; 286 friend class ModulePassManager; 287 friend class FunctionPassManagerT; 288 friend class BasicBlockPassManager; 289 virtual void addToPassManager(ModulePassManager *PM, AnalysisUsage &AU); 290 virtual void addToPassManager(FunctionPassManagerT *PM, AnalysisUsage &AU); 291#endif 292}; 293 294 295 296//===----------------------------------------------------------------------===// 297/// BasicBlockPass class - This class is used to implement most local 298/// optimizations. Optimizations should subclass this class if they 299/// meet the following constraints: 300/// 1. Optimizations are local, operating on either a basic block or 301/// instruction at a time. 302/// 2. Optimizations do not modify the CFG of the contained function, or any 303/// other basic block in the function. 304/// 3. Optimizations conform to all of the constraints of FunctionPasses. 305/// 306class BasicBlockPass : public FunctionPass { 307public: 308 /// doInitialization - Virtual method overridden by subclasses to do 309 /// any necessary per-module initialization. 310 /// 311 virtual bool doInitialization(Module &M) { return false; } 312 313 /// doInitialization - Virtual method overridden by BasicBlockPass subclasses 314 /// to do any necessary per-function initialization. 315 /// 316 virtual bool doInitialization(Function &F) { return false; } 317 318 /// runOnBasicBlock - Virtual method overriden by subclasses to do the 319 /// per-basicblock processing of the pass. 320 /// 321 virtual bool runOnBasicBlock(BasicBlock &BB) = 0; 322 323 /// doFinalization - Virtual method overriden by BasicBlockPass subclasses to 324 /// do any post processing needed after all passes have run. 325 /// 326 virtual bool doFinalization(Function &F) { return false; } 327 328 /// doFinalization - Virtual method overriden by subclasses to do any post 329 /// processing needed after all passes have run. 330 /// 331 virtual bool doFinalization(Module &M) { return false; } 332 333 334 // To run this pass on a function, we simply call runOnBasicBlock once for 335 // each function. 336 // 337 bool runOnFunction(Function &F); 338 339 /// To run directly on the basic block, we initialize, runOnBasicBlock, then 340 /// finalize. 341 /// 342 virtual bool runPass(Module &M) { return false; } 343 virtual bool runPass(BasicBlock &BB); 344 345#ifdef USE_OLD_PASSMANAGER 346private: 347 template<typename Trait> friend class PassManagerT; 348 friend class FunctionPassManagerT; 349 friend class BasicBlockPassManager; 350 virtual void addToPassManager(ModulePassManager *PM, AnalysisUsage &AU) { 351 FunctionPass::addToPassManager(PM, AU); 352 } 353 virtual void addToPassManager(FunctionPassManagerT *PM, AnalysisUsage &AU); 354 virtual void addToPassManager(BasicBlockPassManager *PM,AnalysisUsage &AU); 355#endif 356}; 357 358/// If the user specifies the -time-passes argument on an LLVM tool command line 359/// then the value of this boolean will be true, otherwise false. 360/// @brief This is the storage for the -time-passes option. 361extern bool TimePassesIsEnabled; 362 363} // End llvm namespace 364 365// Include support files that contain important APIs commonly used by Passes, 366// but that we want to separate out to make it easier to read the header files. 367// 368#include "llvm/PassSupport.h" 369#include "llvm/PassAnalysisSupport.h" 370 371#endif 372