Pass.h revision 90c579de5a383cee278acc3f7e7b9d0a656e6a35
1//===- llvm/Pass.h - Base class for Passes ----------------------*- 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 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/System/DataTypes.h" 33 34#include <string> 35#include <utility> 36#include <vector> 37 38namespace llvm { 39 40class BasicBlock; 41class Function; 42class Module; 43class AnalysisUsage; 44class PassInfo; 45class ImmutablePass; 46class PMStack; 47class AnalysisResolver; 48class PMDataManager; 49class raw_ostream; 50class StringRef; 51 52// AnalysisID - Use the PassInfo to identify a pass... 53typedef const void* AnalysisID; 54 55/// Different types of internal pass managers. External pass managers 56/// (PassManager and FunctionPassManager) are not represented here. 57/// Ordering of pass manager types is important here. 58enum PassManagerType { 59 PMT_Unknown = 0, 60 PMT_ModulePassManager = 1, ///< MPPassManager 61 PMT_CallGraphPassManager, ///< CGPassManager 62 PMT_FunctionPassManager, ///< FPPassManager 63 PMT_LoopPassManager, ///< LPPassManager 64 PMT_BasicBlockPassManager, ///< BBPassManager 65 PMT_Last 66}; 67 68// Different types of passes. 69enum PassKind { 70 PT_BasicBlock, 71 PT_Loop, 72 PT_Function, 73 PT_CallGraphSCC, 74 PT_Module, 75 PT_PassManager 76}; 77 78//===----------------------------------------------------------------------===// 79/// Pass interface - Implemented by all 'passes'. Subclass this if you are an 80/// interprocedural optimization or you do not fit into any of the more 81/// constrained passes described below. 82/// 83class Pass { 84 AnalysisResolver *Resolver; // Used to resolve analysis 85 const void *PassID; 86 PassKind Kind; 87 void operator=(const Pass&); // DO NOT IMPLEMENT 88 Pass(const Pass &); // DO NOT IMPLEMENT 89 90public: 91 explicit Pass(PassKind K, char &pid); 92 virtual ~Pass(); 93 94 95 PassKind getPassKind() const { return Kind; } 96 97 /// getPassName - Return a nice clean name for a pass. This usually 98 /// implemented in terms of the name that is registered by one of the 99 /// Registration templates, but can be overloaded directly. 100 /// 101 virtual const char *getPassName() const; 102 103 /// getPassID - Return the PassID number that corresponds to this pass. 104 virtual AnalysisID getPassID() const { 105 return PassID; 106 } 107 108 /// print - Print out the internal state of the pass. This is called by 109 /// Analyze to print out the contents of an analysis. Otherwise it is not 110 /// necessary to implement this method. Beware that the module pointer MAY be 111 /// null. This automatically forwards to a virtual function that does not 112 /// provide the Module* in case the analysis doesn't need it it can just be 113 /// ignored. 114 /// 115 virtual void print(raw_ostream &O, const Module *M) const; 116 void dump() const; // dump - Print to stderr. 117 118 /// createPrinterPass - Get a Pass appropriate to print the IR this 119 /// pass operates one (Module, Function or MachineFunction). 120 virtual Pass *createPrinterPass(raw_ostream &O, 121 const std::string &Banner) const = 0; 122 123 /// Each pass is responsible for assigning a pass manager to itself. 124 /// PMS is the stack of available pass manager. 125 virtual void assignPassManager(PMStack &, 126 PassManagerType = PMT_Unknown) {} 127 /// Check if available pass managers are suitable for this pass or not. 128 virtual void preparePassManager(PMStack &); 129 130 /// Return what kind of Pass Manager can manage this pass. 131 virtual PassManagerType getPotentialPassManagerType() const; 132 133 // Access AnalysisResolver 134 void setResolver(AnalysisResolver *AR); 135 AnalysisResolver *getResolver() const { return Resolver; } 136 137 /// getAnalysisUsage - This function should be overriden by passes that need 138 /// analysis information to do their job. If a pass specifies that it uses a 139 /// particular analysis result to this function, it can then use the 140 /// getAnalysis<AnalysisType>() function, below. 141 /// 142 virtual void getAnalysisUsage(AnalysisUsage &) const; 143 144 /// releaseMemory() - This member can be implemented by a pass if it wants to 145 /// be able to release its memory when it is no longer needed. The default 146 /// behavior of passes is to hold onto memory for the entire duration of their 147 /// lifetime (which is the entire compile time). For pipelined passes, this 148 /// is not a big deal because that memory gets recycled every time the pass is 149 /// invoked on another program unit. For IP passes, it is more important to 150 /// free memory when it is unused. 151 /// 152 /// Optionally implement this function to release pass memory when it is no 153 /// longer used. 154 /// 155 virtual void releaseMemory(); 156 157 /// getAdjustedAnalysisPointer - This method is used when a pass implements 158 /// an analysis interface through multiple inheritance. If needed, it should 159 /// override this to adjust the this pointer as needed for the specified pass 160 /// info. 161 virtual void *getAdjustedAnalysisPointer(AnalysisID ID); 162 virtual ImmutablePass *getAsImmutablePass(); 163 virtual PMDataManager *getAsPMDataManager(); 164 165 /// verifyAnalysis() - This member can be implemented by a analysis pass to 166 /// check state of analysis information. 167 virtual void verifyAnalysis() const; 168 169 // dumpPassStructure - Implement the -debug-passes=PassStructure option 170 virtual void dumpPassStructure(unsigned Offset = 0); 171 172 // lookupPassInfo - Return the pass info object for the specified pass class, 173 // or null if it is not known. 174 static const PassInfo *lookupPassInfo(const void *TI); 175 176 // lookupPassInfo - Return the pass info object for the pass with the given 177 // argument string, or null if it is not known. 178 static const PassInfo *lookupPassInfo(StringRef Arg); 179 180 /// getAnalysisIfAvailable<AnalysisType>() - Subclasses use this function to 181 /// get analysis information that might be around, for example to update it. 182 /// This is different than getAnalysis in that it can fail (if the analysis 183 /// results haven't been computed), so should only be used if you can handle 184 /// the case when the analysis is not available. This method is often used by 185 /// transformation APIs to update analysis results for a pass automatically as 186 /// the transform is performed. 187 /// 188 template<typename AnalysisType> AnalysisType * 189 getAnalysisIfAvailable() const; // Defined in PassAnalysisSupport.h 190 191 /// mustPreserveAnalysisID - This method serves the same function as 192 /// getAnalysisIfAvailable, but works if you just have an AnalysisID. This 193 /// obviously cannot give you a properly typed instance of the class if you 194 /// don't have the class name available (use getAnalysisIfAvailable if you 195 /// do), but it can tell you if you need to preserve the pass at least. 196 /// 197 bool mustPreserveAnalysisID(char &AID) const; 198 199 /// getAnalysis<AnalysisType>() - This function is used by subclasses to get 200 /// to the analysis information that they claim to use by overriding the 201 /// getAnalysisUsage function. 202 /// 203 template<typename AnalysisType> 204 AnalysisType &getAnalysis() const; // Defined in PassAnalysisSupport.h 205 206 template<typename AnalysisType> 207 AnalysisType &getAnalysis(Function &F); // Defined in PassAnalysisSupport.h 208 209 template<typename AnalysisType> 210 AnalysisType &getAnalysisID(AnalysisID PI) const; 211 212 template<typename AnalysisType> 213 AnalysisType &getAnalysisID(AnalysisID PI, Function &F); 214}; 215 216 217//===----------------------------------------------------------------------===// 218/// ModulePass class - This class is used to implement unstructured 219/// interprocedural optimizations and analyses. ModulePasses may do anything 220/// they want to the program. 221/// 222class ModulePass : public Pass { 223public: 224 /// createPrinterPass - Get a module printer pass. 225 Pass *createPrinterPass(raw_ostream &O, const std::string &Banner) const; 226 227 /// runOnModule - Virtual method overriden by subclasses to process the module 228 /// being operated on. 229 virtual bool runOnModule(Module &M) = 0; 230 231 virtual void assignPassManager(PMStack &PMS, 232 PassManagerType T = PMT_ModulePassManager); 233 234 /// Return what kind of Pass Manager can manage this pass. 235 virtual PassManagerType getPotentialPassManagerType() const; 236 237 explicit ModulePass(char &pid) : Pass(PT_Module, pid) {} 238 // Force out-of-line virtual method. 239 virtual ~ModulePass(); 240}; 241 242 243//===----------------------------------------------------------------------===// 244/// ImmutablePass class - This class is used to provide information that does 245/// not need to be run. This is useful for things like target information and 246/// "basic" versions of AnalysisGroups. 247/// 248class ImmutablePass : public ModulePass { 249public: 250 /// initializePass - This method may be overriden by immutable passes to allow 251 /// them to perform various initialization actions they require. This is 252 /// primarily because an ImmutablePass can "require" another ImmutablePass, 253 /// and if it does, the overloaded version of initializePass may get access to 254 /// these passes with getAnalysis<>. 255 /// 256 virtual void initializePass(); 257 258 virtual ImmutablePass *getAsImmutablePass() { return this; } 259 260 /// ImmutablePasses are never run. 261 /// 262 bool runOnModule(Module &) { return false; } 263 264 explicit ImmutablePass(char &pid) 265 : ModulePass(pid) {} 266 267 // Force out-of-line virtual method. 268 virtual ~ImmutablePass(); 269}; 270 271//===----------------------------------------------------------------------===// 272/// FunctionPass class - This class is used to implement most global 273/// optimizations. Optimizations should subclass this class if they meet the 274/// following constraints: 275/// 276/// 1. Optimizations are organized globally, i.e., a function at a time 277/// 2. Optimizing a function does not cause the addition or removal of any 278/// functions in the module 279/// 280class FunctionPass : public Pass { 281public: 282 explicit FunctionPass(char &pid) : Pass(PT_Function, pid) {} 283 284 /// createPrinterPass - Get a function printer pass. 285 Pass *createPrinterPass(raw_ostream &O, const std::string &Banner) const; 286 287 /// doInitialization - Virtual method overridden by subclasses to do 288 /// any necessary per-module initialization. 289 /// 290 virtual bool doInitialization(Module &); 291 292 /// runOnFunction - Virtual method overriden by subclasses to do the 293 /// per-function processing of the pass. 294 /// 295 virtual bool runOnFunction(Function &F) = 0; 296 297 /// doFinalization - Virtual method overriden by subclasses to do any post 298 /// processing needed after all passes have run. 299 /// 300 virtual bool doFinalization(Module &); 301 302 /// runOnModule - On a module, we run this pass by initializing, 303 /// ronOnFunction'ing once for every function in the module, then by 304 /// finalizing. 305 /// 306 virtual bool runOnModule(Module &M); 307 308 /// run - On a function, we simply initialize, run the function, then 309 /// finalize. 310 /// 311 bool run(Function &F); 312 313 virtual void assignPassManager(PMStack &PMS, 314 PassManagerType T = PMT_FunctionPassManager); 315 316 /// Return what kind of Pass Manager can manage this pass. 317 virtual PassManagerType getPotentialPassManagerType() const; 318}; 319 320 321 322//===----------------------------------------------------------------------===// 323/// BasicBlockPass class - This class is used to implement most local 324/// optimizations. Optimizations should subclass this class if they 325/// meet the following constraints: 326/// 1. Optimizations are local, operating on either a basic block or 327/// instruction at a time. 328/// 2. Optimizations do not modify the CFG of the contained function, or any 329/// other basic block in the function. 330/// 3. Optimizations conform to all of the constraints of FunctionPasses. 331/// 332class BasicBlockPass : public Pass { 333public: 334 explicit BasicBlockPass(char &pid) : Pass(PT_BasicBlock, pid) {} 335 336 /// createPrinterPass - Get a function printer pass. 337 Pass *createPrinterPass(raw_ostream &O, const std::string &Banner) const; 338 339 /// doInitialization - Virtual method overridden by subclasses to do 340 /// any necessary per-module initialization. 341 /// 342 virtual bool doInitialization(Module &); 343 344 /// doInitialization - Virtual method overridden by BasicBlockPass subclasses 345 /// to do any necessary per-function initialization. 346 /// 347 virtual bool doInitialization(Function &); 348 349 /// runOnBasicBlock - Virtual method overriden by subclasses to do the 350 /// per-basicblock processing of the pass. 351 /// 352 virtual bool runOnBasicBlock(BasicBlock &BB) = 0; 353 354 /// doFinalization - Virtual method overriden by BasicBlockPass subclasses to 355 /// do any post processing needed after all passes have run. 356 /// 357 virtual bool doFinalization(Function &); 358 359 /// doFinalization - Virtual method overriden by subclasses to do any post 360 /// processing needed after all passes have run. 361 /// 362 virtual bool doFinalization(Module &); 363 364 365 // To run this pass on a function, we simply call runOnBasicBlock once for 366 // each function. 367 // 368 bool runOnFunction(Function &F); 369 370 virtual void assignPassManager(PMStack &PMS, 371 PassManagerType T = PMT_BasicBlockPassManager); 372 373 /// Return what kind of Pass Manager can manage this pass. 374 virtual PassManagerType getPotentialPassManagerType() const; 375}; 376 377/// If the user specifies the -time-passes argument on an LLVM tool command line 378/// then the value of this boolean will be true, otherwise false. 379/// @brief This is the storage for the -time-passes option. 380extern bool TimePassesIsEnabled; 381 382} // End llvm namespace 383 384// Include support files that contain important APIs commonly used by Passes, 385// but that we want to separate out to make it easier to read the header files. 386// 387#include "llvm/PassSupport.h" 388#include "llvm/PassAnalysisSupport.h" 389 390#endif 391