//===- llvm/Pass.h - Base class for Passes ----------------------*- C++ -*-===// // // The LLVM Compiler Infrastructure // // This file was developed by the LLVM research group and 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. // // Pass's 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 effeciently 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 #include #include #include #include namespace llvm { class Value; struct BasicBlock; class Function; class Module; class AnalysisUsage; class PassInfo; class ImmutablePass; template class PassManagerT; struct AnalysisResolver; // AnalysisID - Use the PassInfo to identify a pass... typedef const PassInfo* AnalysisID; //===----------------------------------------------------------------------===// /// 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 { friend class AnalysisResolver; AnalysisResolver *Resolver; // AnalysisResolver this pass is owned by... const PassInfo *PassInfoCache; // AnalysisImpls - This keeps track of which passes implement the interfaces // that are required by the current pass (to implement getAnalysis()). // std::vector > AnalysisImpls; void operator=(const Pass&); // DO NOT IMPLEMENT Pass(const Pass &); // DO NOT IMPLEMENT public: Pass() : Resolver(0), PassInfoCache(0) {} virtual ~Pass() {} // Destructor is virtual so we can be subclassed /// 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, and if nothing /// else is available, C++ RTTI will be consulted to get a SOMEWHAT /// intelligible name for the pass. /// virtual const char *getPassName() const; /// getPassInfo - Return the PassInfo data structure that corresponds to this /// pass... If the pass has not been registered, this will return null. /// const PassInfo *getPassInfo() const; /// run - Run this pass, returning true if a modification was made to the /// module argument. This should be implemented by all concrete subclasses. /// virtual bool run(Module &M) = 0; /// 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(std::ostream &O, const Module *M) const { print(O); } virtual void print(std::ostream &O) const; void dump() const; // dump - call print(std::cerr, 0); /// 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() function, below. /// virtual void getAnalysisUsage(AnalysisUsage &Info) const { // By default, no analysis results are used, all are invalidated. } /// 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() {} // dumpPassStructure - Implement the -debug-passes=PassStructure option virtual void dumpPassStructure(unsigned Offset = 0); // getPassInfo - Static method to get the pass information from a class name. template static const PassInfo *getClassPassInfo() { return lookupPassInfo(typeid(AnalysisClass)); } // lookupPassInfo - Return the pass info object for the specified pass class, // or null if it is not known. static const PassInfo *lookupPassInfo(const std::type_info &TI); /// getAnalysisToUpdate() - This function is used by subclasses /// to get to the analysis information that might be around that needs to be /// updated. This is different than getAnalysis in that it can fail (ie the /// analysis results haven't been computed), so should only be used if you /// provide the capability to update an analysis that exists. This method is /// often used by transformation APIs to update analysis results for a pass /// automatically as the transform is performed. /// template AnalysisType *getAnalysisToUpdate() const; // Defined in PassAnalysisSupport.h /// mustPreserveAnalysisID - This method serves the same function as /// getAnalysisToUpdate, 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 getAnalysisToUpdate if you do), /// but it can tell you if you need to preserve the pass at least. /// bool mustPreserveAnalysisID(const PassInfo *AnalysisID) const; /// getAnalysis() - This function is used by subclasses to get /// to the analysis information that they claim to use by overriding the /// getAnalysisUsage function. /// template AnalysisType &getAnalysis() const { assert(Resolver && "Pass has not been inserted into a PassManager object!"); const PassInfo *PI = getClassPassInfo(); return getAnalysisID(PI); } template AnalysisType &getAnalysisID(const PassInfo *PI) const { assert(Resolver && "Pass has not been inserted into a PassManager object!"); assert(PI && "getAnalysis for unregistered pass!"); // PI *must* appear in AnalysisImpls. Because the number of passes used // should be a small number, we just do a linear search over a (dense) // vector. Pass *ResultPass = 0; for (unsigned i = 0; ; ++i) { assert(i != AnalysisImpls.size() && "getAnalysis*() called on an analysis that was not " "'required' by pass!"); if (AnalysisImpls[i].first == PI) { ResultPass = AnalysisImpls[i].second; break; } } // Because the AnalysisType may not be a subclass of pass (for // AnalysisGroups), we must use dynamic_cast here to potentially adjust the // return pointer (because the class may multiply inherit, once from pass, // once from AnalysisType). // AnalysisType *Result = dynamic_cast(ResultPass); assert(Result && "Pass does not implement interface required!"); return *Result; } private: friend class PassManagerT; friend class PassManagerT; friend class PassManagerT; virtual void addToPassManager(PassManagerT *PM, AnalysisUsage &AU); }; inline std::ostream &operator<<(std::ostream &OS, const Pass &P) { P.print(OS, 0); return OS; } //===----------------------------------------------------------------------===// /// 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. /// struct ImmutablePass : public Pass { /// 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() {} /// ImmutablePasses are never run. /// virtual bool run(Module &M) { return false; } private: friend class PassManagerT; virtual void addToPassManager(PassManagerT *PM, AnalysisUsage &AU); }; //===----------------------------------------------------------------------===// /// 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 /// struct FunctionPass : public Pass { /// doInitialization - Virtual method overridden by subclasses to do /// any necessary per-module initialization. /// virtual bool doInitialization(Module &M) { return false; } /// runOnFunction - Virtual method overriden by subclasses to do the /// per-function processing of the pass. /// virtual bool runOnFunction(Function &F) = 0; /// doFinalization - Virtual method overriden by subclasses to do any post /// processing needed after all passes have run. /// virtual bool doFinalization(Module &M) { return false; } /// run - On a module, we run this pass by initializing, ronOnFunction'ing /// once for every function in the module, then by finalizing. /// virtual bool run(Module &M); /// run - On a function, we simply initialize, run the function, then /// finalize. /// bool run(Function &F); private: friend class PassManagerT; friend class PassManagerT; friend class PassManagerT; virtual void addToPassManager(PassManagerT *PM, AnalysisUsage &AU); virtual void addToPassManager(PassManagerT *PM, AnalysisUsage &AU); }; //===----------------------------------------------------------------------===// /// 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 FunctionPass's. /// struct BasicBlockPass : public FunctionPass { /// doInitialization - Virtual method overridden by subclasses to do /// any necessary per-module initialization. /// virtual bool doInitialization(Module &M) { return false; } /// doInitialization - Virtual method overridden by BasicBlockPass subclasses /// to do any necessary per-function initialization. /// virtual bool doInitialization(Function &F) { return false; } /// 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 &F) { return false; } /// doFinalization - Virtual method overriden by subclasses to do any post /// processing needed after all passes have run. /// virtual bool doFinalization(Module &M) { return false; } // To run this pass on a function, we simply call runOnBasicBlock once for // each function. // bool runOnFunction(Function &F); /// To run directly on the basic block, we initialize, runOnBasicBlock, then /// finalize. /// bool run(BasicBlock &BB); private: friend class PassManagerT; friend class PassManagerT; virtual void addToPassManager(PassManagerT *PM, AnalysisUsage &AU); virtual void addToPassManager(PassManagerT *PM,AnalysisUsage &AU); }; /// 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; } // 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/PassSupport.h" #include "llvm/PassAnalysisSupport.h" #endif