//===- llvm/Pass.h - Base class for Passes ----------------------*- C++ -*-===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // This file defines a base class that indicates that a specified class is a // transformation pass implementation. // // Passes are designed this way so that it is possible to run passes in a cache // and organizationally optimal order without having to specify it at the front // end. This allows arbitrary passes to be strung together and have them // executed as efficiently as possible. // // Passes should extend one of the classes below, depending on the guarantees // that it can make about what will be modified as it is run. For example, most // global optimizations should derive from FunctionPass, because they do not add // or delete functions, they operate on the internals of the function. // // Note that this file #includes PassSupport.h and PassAnalysisSupport.h (at the // bottom), so the APIs exposed by these files are also automatically available // to all users of this file. // //===----------------------------------------------------------------------===// #ifndef LLVM_PASS_H #define LLVM_PASS_H #include <string> namespace llvm { class BasicBlock; class Function; class Module; class AnalysisUsage; class PassInfo; class ImmutablePass; class PMStack; class AnalysisResolver; class PMDataManager; class raw_ostream; class StringRef; // AnalysisID - Use the PassInfo to identify a pass... typedef const void* AnalysisID; /// Different types of internal pass managers. External pass managers /// (PassManager and FunctionPassManager) are not represented here. /// Ordering of pass manager types is important here. enum PassManagerType { PMT_Unknown = 0, PMT_ModulePassManager = 1, ///< MPPassManager PMT_CallGraphPassManager, ///< CGPassManager PMT_FunctionPassManager, ///< FPPassManager PMT_LoopPassManager, ///< LPPassManager PMT_RegionPassManager, ///< RGPassManager PMT_BasicBlockPassManager, ///< BBPassManager PMT_Last }; // Different types of passes. enum PassKind { PT_BasicBlock, PT_Region, PT_Loop, PT_Function, PT_CallGraphSCC, PT_Module, PT_PassManager }; //===----------------------------------------------------------------------===// /// Pass interface - Implemented by all 'passes'. Subclass this if you are an /// interprocedural optimization or you do not fit into any of the more /// constrained passes described below. /// class Pass { AnalysisResolver *Resolver; // Used to resolve analysis const void *PassID; PassKind Kind; void operator=(const Pass&) = delete; Pass(const Pass &) = delete; public: explicit Pass(PassKind K, char &pid) : Resolver(nullptr), PassID(&pid), Kind(K) { } virtual ~Pass(); PassKind getPassKind() const { return Kind; } /// getPassName - Return a nice clean name for a pass. This usually /// implemented in terms of the name that is registered by one of the /// Registration templates, but can be overloaded directly. /// virtual StringRef getPassName() const; /// getPassID - Return the PassID number that corresponds to this pass. AnalysisID getPassID() const { return PassID; } /// doInitialization - Virtual method overridden by subclasses to do /// any necessary initialization before any pass is run. /// virtual bool doInitialization(Module &) { return false; } /// doFinalization - Virtual method overriden by subclasses to do any /// necessary clean up after all passes have run. /// virtual bool doFinalization(Module &) { return false; } /// print - Print out the internal state of the pass. This is called by /// Analyze to print out the contents of an analysis. Otherwise it is not /// necessary to implement this method. Beware that the module pointer MAY be /// null. This automatically forwards to a virtual function that does not /// provide the Module* in case the analysis doesn't need it it can just be /// ignored. /// virtual void print(raw_ostream &O, const Module *M) const; void dump() const; // dump - Print to stderr. /// createPrinterPass - Get a Pass appropriate to print the IR this /// pass operates on (Module, Function or MachineFunction). virtual Pass *createPrinterPass(raw_ostream &O, const std::string &Banner) const = 0; /// Each pass is responsible for assigning a pass manager to itself. /// PMS is the stack of available pass manager. virtual void assignPassManager(PMStack &, PassManagerType) {} /// Check if available pass managers are suitable for this pass or not. virtual void preparePassManager(PMStack &); /// Return what kind of Pass Manager can manage this pass. virtual PassManagerType getPotentialPassManagerType() const; // Access AnalysisResolver void setResolver(AnalysisResolver *AR); AnalysisResolver *getResolver() const { return Resolver; } /// getAnalysisUsage - This function should be overriden by passes that need /// analysis information to do their job. If a pass specifies that it uses a /// particular analysis result to this function, it can then use the /// getAnalysis<AnalysisType>() function, below. /// virtual void getAnalysisUsage(AnalysisUsage &) const; /// releaseMemory() - This member can be implemented by a pass if it wants to /// be able to release its memory when it is no longer needed. The default /// behavior of passes is to hold onto memory for the entire duration of their /// lifetime (which is the entire compile time). For pipelined passes, this /// is not a big deal because that memory gets recycled every time the pass is /// invoked on another program unit. For IP passes, it is more important to /// free memory when it is unused. /// /// Optionally implement this function to release pass memory when it is no /// longer used. /// virtual void releaseMemory(); /// getAdjustedAnalysisPointer - This method is used when a pass implements /// an analysis interface through multiple inheritance. If needed, it should /// override this to adjust the this pointer as needed for the specified pass /// info. virtual void *getAdjustedAnalysisPointer(AnalysisID ID); virtual ImmutablePass *getAsImmutablePass(); virtual PMDataManager *getAsPMDataManager(); /// verifyAnalysis() - This member can be implemented by a analysis pass to /// check state of analysis information. virtual void verifyAnalysis() const; // dumpPassStructure - Implement the -debug-passes=PassStructure option virtual void dumpPassStructure(unsigned Offset = 0); // lookupPassInfo - Return the pass info object for the specified pass class, // or null if it is not known. static const PassInfo *lookupPassInfo(const void *TI); // lookupPassInfo - Return the pass info object for the pass with the given // argument string, or null if it is not known. static const PassInfo *lookupPassInfo(StringRef Arg); // createPass - Create a object for the specified pass class, // or null if it is not known. static Pass *createPass(AnalysisID ID); /// getAnalysisIfAvailable<AnalysisType>() - Subclasses use this function to /// get analysis information that might be around, for example to update it. /// This is different than getAnalysis in that it can fail (if the analysis /// results haven't been computed), so should only be used if you can handle /// the case when the analysis is not available. This method is often used by /// transformation APIs to update analysis results for a pass automatically as /// the transform is performed. /// template<typename AnalysisType> AnalysisType * getAnalysisIfAvailable() const; // Defined in PassAnalysisSupport.h /// mustPreserveAnalysisID - This method serves the same function as /// getAnalysisIfAvailable, but works if you just have an AnalysisID. This /// obviously cannot give you a properly typed instance of the class if you /// don't have the class name available (use getAnalysisIfAvailable if you /// do), but it can tell you if you need to preserve the pass at least. /// bool mustPreserveAnalysisID(char &AID) const; /// getAnalysis<AnalysisType>() - This function is used by subclasses to get /// to the analysis information that they claim to use by overriding the /// getAnalysisUsage function. /// template<typename AnalysisType> AnalysisType &getAnalysis() const; // Defined in PassAnalysisSupport.h template<typename AnalysisType> AnalysisType &getAnalysis(Function &F); // Defined in PassAnalysisSupport.h template<typename AnalysisType> AnalysisType &getAnalysisID(AnalysisID PI) const; template<typename AnalysisType> AnalysisType &getAnalysisID(AnalysisID PI, Function &F); }; //===----------------------------------------------------------------------===// /// ModulePass class - This class is used to implement unstructured /// interprocedural optimizations and analyses. ModulePasses may do anything /// they want to the program. /// class ModulePass : public Pass { public: /// createPrinterPass - Get a module printer pass. Pass *createPrinterPass(raw_ostream &O, const std::string &Banner) const override; /// runOnModule - Virtual method overriden by subclasses to process the module /// being operated on. virtual bool runOnModule(Module &M) = 0; void assignPassManager(PMStack &PMS, PassManagerType T) override; /// Return what kind of Pass Manager can manage this pass. PassManagerType getPotentialPassManagerType() const override; explicit ModulePass(char &pid) : Pass(PT_Module, pid) {} // Force out-of-line virtual method. ~ModulePass() override; protected: /// Optional passes call this function to check whether the pass should be /// skipped. This is the case when optimization bisect is over the limit. bool skipModule(Module &M) const; }; //===----------------------------------------------------------------------===// /// ImmutablePass class - This class is used to provide information that does /// not need to be run. This is useful for things like target information and /// "basic" versions of AnalysisGroups. /// class ImmutablePass : public ModulePass { public: /// initializePass - This method may be overriden by immutable passes to allow /// them to perform various initialization actions they require. This is /// primarily because an ImmutablePass can "require" another ImmutablePass, /// and if it does, the overloaded version of initializePass may get access to /// these passes with getAnalysis<>. /// virtual void initializePass(); ImmutablePass *getAsImmutablePass() override { return this; } /// ImmutablePasses are never run. /// bool runOnModule(Module &) override { return false; } explicit ImmutablePass(char &pid) : ModulePass(pid) {} // Force out-of-line virtual method. ~ImmutablePass() override; }; //===----------------------------------------------------------------------===// /// FunctionPass class - This class is used to implement most global /// optimizations. Optimizations should subclass this class if they meet the /// following constraints: /// /// 1. Optimizations are organized globally, i.e., a function at a time /// 2. Optimizing a function does not cause the addition or removal of any /// functions in the module /// class FunctionPass : public Pass { public: explicit FunctionPass(char &pid) : Pass(PT_Function, pid) {} /// createPrinterPass - Get a function printer pass. Pass *createPrinterPass(raw_ostream &O, const std::string &Banner) const override; /// runOnFunction - Virtual method overriden by subclasses to do the /// per-function processing of the pass. /// virtual bool runOnFunction(Function &F) = 0; void assignPassManager(PMStack &PMS, PassManagerType T) override; /// Return what kind of Pass Manager can manage this pass. PassManagerType getPotentialPassManagerType() const override; protected: /// Optional passes call this function to check whether the pass should be /// skipped. This is the case when Attribute::OptimizeNone is set or when /// optimization bisect is over the limit. bool skipFunction(const Function &F) const; }; //===----------------------------------------------------------------------===// /// BasicBlockPass class - This class is used to implement most local /// optimizations. Optimizations should subclass this class if they /// meet the following constraints: /// 1. Optimizations are local, operating on either a basic block or /// instruction at a time. /// 2. Optimizations do not modify the CFG of the contained function, or any /// other basic block in the function. /// 3. Optimizations conform to all of the constraints of FunctionPasses. /// class BasicBlockPass : public Pass { public: explicit BasicBlockPass(char &pid) : Pass(PT_BasicBlock, pid) {} /// createPrinterPass - Get a basic block printer pass. Pass *createPrinterPass(raw_ostream &O, const std::string &Banner) const override; using llvm::Pass::doInitialization; using llvm::Pass::doFinalization; /// doInitialization - Virtual method overridden by BasicBlockPass subclasses /// to do any necessary per-function initialization. /// virtual bool doInitialization(Function &); /// runOnBasicBlock - Virtual method overriden by subclasses to do the /// per-basicblock processing of the pass. /// virtual bool runOnBasicBlock(BasicBlock &BB) = 0; /// doFinalization - Virtual method overriden by BasicBlockPass subclasses to /// do any post processing needed after all passes have run. /// virtual bool doFinalization(Function &); void assignPassManager(PMStack &PMS, PassManagerType T) override; /// Return what kind of Pass Manager can manage this pass. PassManagerType getPotentialPassManagerType() const override; protected: /// Optional passes call this function to check whether the pass should be /// skipped. This is the case when Attribute::OptimizeNone is set or when /// optimization bisect is over the limit. bool skipBasicBlock(const BasicBlock &BB) const; }; /// If the user specifies the -time-passes argument on an LLVM tool command line /// then the value of this boolean will be true, otherwise false. /// @brief This is the storage for the -time-passes option. extern bool TimePassesIsEnabled; /// isFunctionInPrintList - returns true if a function should be printed via // debugging options like -print-after-all/-print-before-all. // @brief Tells if the function IR should be printed by PrinterPass. extern bool isFunctionInPrintList(StringRef FunctionName); } // End llvm namespace // Include support files that contain important APIs commonly used by Passes, // but that we want to separate out to make it easier to read the header files. // #include "llvm/PassAnalysisSupport.h" #include "llvm/PassSupport.h" #endif