LLVM API Documentation

PassSupport.h

Go to the documentation of this file.
00001 //===- llvm/PassSupport.h - Pass Support code -------------------*- C++ -*-===//
00002 //
00003 //                     The LLVM Compiler Infrastructure
00004 //
00005 // This file was developed by the LLVM research group and is distributed under
00006 // the University of Illinois Open Source License. See LICENSE.TXT for details.
00007 //
00008 //===----------------------------------------------------------------------===//
00009 //
00010 // This file defines stuff that is used to define and "use" Passes.  This file
00011 // is automatically #included by Pass.h, so:
00012 //
00013 //           NO .CPP FILES SHOULD INCLUDE THIS FILE DIRECTLY
00014 //
00015 // Instead, #include Pass.h.
00016 //
00017 // This file defines Pass registration code and classes used for it.
00018 //
00019 //===----------------------------------------------------------------------===//
00020 
00021 #ifndef LLVM_PASS_SUPPORT_H
00022 #define LLVM_PASS_SUPPORT_H
00023 
00024 #include "llvm/System/IncludeFile.h"
00025 // No need to include Pass.h, we are being included by it!
00026 
00027 namespace llvm {
00028 
00029 class TargetMachine;
00030 
00031 //===---------------------------------------------------------------------------
00032 /// PassInfo class - An instance of this class exists for every pass known by
00033 /// the system, and can be obtained from a live Pass by calling its
00034 /// getPassInfo() method.  These objects are set up by the RegisterPass<>
00035 /// template, defined below.
00036 ///
00037 class PassInfo {
00038   const char           *PassName;      // Nice name for Pass
00039   const char           *PassArgument;  // Command Line argument to run this pass
00040   const std::type_info &TypeInfo;      // type_info object for this Pass class
00041   unsigned char PassType;              // Set of enums values below...
00042   std::vector<const PassInfo*> ItfImpl;// Interfaces implemented by this pass
00043 
00044   Pass *(*NormalCtor)();               // No argument ctor
00045   Pass *(*TargetCtor)(TargetMachine&);   // Ctor taking TargetMachine object...
00046 
00047 public:
00048   /// PassType - Define symbolic constants that can be used to test to see if
00049   /// this pass should be listed by analyze or opt.  Passes can use none, one or
00050   /// many of these flags or'd together.  It is not legal to combine the
00051   /// AnalysisGroup flag with others.
00052   ///
00053   enum {
00054     Analysis = 1, Optimization = 2, AnalysisGroup = 4
00055   };
00056 
00057   /// PassInfo ctor - Do not call this directly, this should only be invoked
00058   /// through RegisterPass.
00059   PassInfo(const char *name, const char *arg, const std::type_info &ti,
00060            unsigned char pt, Pass *(*normal)() = 0,
00061            Pass *(*targetctor)(TargetMachine &) = 0)
00062     : PassName(name), PassArgument(arg), TypeInfo(ti), PassType(pt),
00063       NormalCtor(normal), TargetCtor(targetctor)  {
00064   }
00065 
00066   /// getPassName - Return the friendly name for the pass, never returns null
00067   ///
00068   const char *getPassName() const { return PassName; }
00069   void setPassName(const char *Name) { PassName = Name; }
00070 
00071   /// getPassArgument - Return the command line option that may be passed to
00072   /// 'opt' that will cause this pass to be run.  This will return null if there
00073   /// is no argument.
00074   ///
00075   const char *getPassArgument() const { return PassArgument; }
00076 
00077   /// getTypeInfo - Return the type_info object for the pass...
00078   ///
00079   const std::type_info &getTypeInfo() const { return TypeInfo; }
00080 
00081   /// getPassType - Return the PassType of a pass.  Note that this can be
00082   /// several different types or'd together.  This is _strictly_ for use by opt,
00083   /// analyze and llc for deciding which passes to use as command line options.
00084   ///
00085   unsigned getPassType() const { return PassType; }
00086 
00087   /// getNormalCtor - Return a pointer to a function, that when called, creates
00088   /// an instance of the pass and returns it.  This pointer may be null if there
00089   /// is no default constructor for the pass.
00090   ///
00091   Pass *(*getNormalCtor() const)() {
00092     return NormalCtor;
00093   }
00094   void setNormalCtor(Pass *(*Ctor)()) {
00095     NormalCtor = Ctor;
00096   }
00097 
00098   /// createPass() - Use this method to create an instance of this pass.
00099   Pass *createPass() const {
00100     assert((PassType != AnalysisGroup || NormalCtor) &&
00101            "No default implementation found for analysis group!");
00102     assert(NormalCtor &&
00103            "Cannot call createPass on PassInfo without default ctor!");
00104     return NormalCtor();
00105   }
00106 
00107   /// getTargetCtor - Return a pointer to a function that creates an instance of
00108   /// the pass and returns it.  This returns a constructor for a version of the
00109   /// pass that takes a TargetMachine object as a parameter.
00110   ///
00111   Pass *(*getTargetCtor() const)(TargetMachine &) {
00112     return TargetCtor;
00113   }
00114 
00115   /// addInterfaceImplemented - This method is called when this pass is
00116   /// registered as a member of an analysis group with the RegisterAnalysisGroup
00117   /// template.
00118   ///
00119   void addInterfaceImplemented(const PassInfo *ItfPI) {
00120     ItfImpl.push_back(ItfPI);
00121   }
00122 
00123   /// getInterfacesImplemented - Return a list of all of the analysis group
00124   /// interfaces implemented by this pass.
00125   ///
00126   const std::vector<const PassInfo*> &getInterfacesImplemented() const {
00127     return ItfImpl;
00128   }
00129 };
00130 
00131 
00132 //===---------------------------------------------------------------------------
00133 /// RegisterPass<t> template - This template class is used to notify the system
00134 /// that a Pass is available for use, and registers it into the internal
00135 /// database maintained by the PassManager.  Unless this template is used, opt,
00136 /// for example will not be able to see the pass and attempts to create the pass
00137 /// will fail. This template is used in the follow manner (at global scope, in
00138 /// your .cpp file):
00139 ///
00140 /// static RegisterPass<YourPassClassName> tmp("passopt", "My Pass Name");
00141 ///
00142 /// This statement will cause your pass to be created by calling the default
00143 /// constructor exposed by the pass.  If you have a different constructor that
00144 /// must be called, create a global constructor function (which takes the
00145 /// arguments you need and returns a Pass*) and register your pass like this:
00146 ///
00147 /// Pass *createMyPass(foo &opt) { return new MyPass(opt); }
00148 /// static RegisterPass<PassClassName> tmp("passopt", "My Name", createMyPass);
00149 ///
00150 struct RegisterPassBase {
00151   /// getPassInfo - Get the pass info for the registered class...
00152   ///
00153   const PassInfo *getPassInfo() const { return &PIObj; }
00154 
00155   RegisterPassBase(const char *Name, const char *Arg, const std::type_info &TI,
00156                    unsigned char PT, Pass *(*Normal)() = 0,
00157                    Pass *(*TargetCtor)(TargetMachine &) = 0)
00158     : PIObj(Name, Arg, TI, PT, Normal, TargetCtor) {
00159     registerPass();
00160   }
00161   RegisterPassBase(const std::type_info &TI, unsigned char PT)
00162     : PIObj("", "", TI, PT, 0, 0) {
00163     // This ctor may only be used for analysis groups: it does not auto-register
00164     // the pass.
00165     assert(PT == PassInfo::AnalysisGroup && "Not an AnalysisGroup!");
00166   }
00167   
00168   ~RegisterPassBase() {   // Intentionally non-virtual.
00169     // Analysis groups are registered/unregistered by their dtor.
00170     if (PIObj.getPassType() != PassInfo::AnalysisGroup)
00171       unregisterPass();
00172   }
00173 
00174 protected:
00175   PassInfo PIObj;       // The PassInfo object for this pass
00176   void registerPass();
00177   void unregisterPass();
00178 
00179   /// setOnlyUsesCFG - Notice that this pass only depends on the CFG, so
00180   /// transformations that do not modify the CFG do not invalidate this pass.
00181   ///
00182   void setOnlyUsesCFG();
00183 };
00184 
00185 template<typename PassName>
00186 Pass *callDefaultCtor() { return new PassName(); }
00187 
00188 template<typename PassName>
00189 struct RegisterPass : public RegisterPassBase {
00190 
00191   // Register Pass using default constructor...
00192   RegisterPass(const char *PassArg, const char *Name, unsigned char PassTy = 0)
00193   : RegisterPassBase(Name, PassArg, typeid(PassName), PassTy,
00194                      callDefaultCtor<PassName>) {}
00195 
00196   // Register Pass using default constructor explicitly...
00197   RegisterPass(const char *PassArg, const char *Name, unsigned char PassTy,
00198                Pass *(*ctor)()) 
00199   : RegisterPassBase(Name, PassArg, typeid(PassName), PassTy, ctor) {}
00200 
00201   // Register Pass using TargetMachine constructor...
00202   RegisterPass(const char *PassArg, const char *Name, unsigned char PassTy,
00203                Pass *(*targetctor)(TargetMachine &))
00204   : RegisterPassBase(Name, PassArg, typeid(PassName), PassTy,
00205                      0, targetctor) {}
00206 
00207   // Generic constructor version that has an unknown ctor type...
00208   template<typename CtorType>
00209   RegisterPass(const char *PassArg, const char *Name, unsigned char PassTy,
00210                CtorType *Fn)
00211   : RegisterPassBase(Name, PassArg, typeid(PassName), PassTy, 0) {}
00212 };
00213 
00214 /// RegisterOpt - Register something that is to show up in Opt, this is just a
00215 /// shortcut for specifying RegisterPass...
00216 ///
00217 template<typename PassName>
00218 struct RegisterOpt : public RegisterPassBase {
00219   RegisterOpt(const char *PassArg, const char *Name, bool CFGOnly = false)
00220   : RegisterPassBase(Name, PassArg, typeid(PassName), PassInfo::Optimization,
00221                      callDefaultCtor<PassName>) {
00222     if (CFGOnly) setOnlyUsesCFG();
00223   }
00224 
00225   /// Register Pass using default constructor explicitly...
00226   ///
00227   RegisterOpt(const char *PassArg, const char *Name, Pass *(*ctor)(),
00228               bool CFGOnly = false) 
00229   : RegisterPassBase(Name, PassArg, typeid(PassName),
00230                      PassInfo::Optimization, ctor) {
00231     if (CFGOnly) setOnlyUsesCFG();
00232   }
00233 
00234   /// Register FunctionPass using default constructor explicitly...
00235   ///
00236   RegisterOpt(const char *PassArg, const char *Name, FunctionPass *(*ctor)(),
00237               bool CFGOnly = false)
00238   : RegisterPassBase(Name, PassArg, typeid(PassName), PassInfo::Optimization,
00239                      static_cast<Pass*(*)()>(ctor)) {
00240     if (CFGOnly) setOnlyUsesCFG();
00241   }
00242 
00243   /// Register Pass using TargetMachine constructor...
00244   ///
00245   RegisterOpt(const char *PassArg, const char *Name,
00246                Pass *(*targetctor)(TargetMachine &), bool CFGOnly = false)
00247   : RegisterPassBase(Name, PassArg, typeid(PassName),
00248                      PassInfo::Optimization, 0, targetctor) {
00249     if (CFGOnly) setOnlyUsesCFG();
00250   }
00251 
00252   /// Register FunctionPass using TargetMachine constructor...
00253   ///
00254   RegisterOpt(const char *PassArg, const char *Name,
00255               FunctionPass *(*targetctor)(TargetMachine &),
00256               bool CFGOnly = false)
00257   : RegisterPassBase(Name, PassArg, typeid(PassName), PassInfo::Optimization, 0,
00258                      static_cast<Pass*(*)(TargetMachine&)>(targetctor)) {
00259     if (CFGOnly) setOnlyUsesCFG();
00260   }
00261 };
00262 
00263 /// RegisterAnalysis - Register something that is to show up in Analysis, this
00264 /// is just a shortcut for specifying RegisterPass...  Analyses take a special
00265 /// argument that, when set to true, tells the system that the analysis ONLY
00266 /// depends on the shape of the CFG, so if a transformation preserves the CFG
00267 /// that the analysis is not invalidated.
00268 ///
00269 template<typename PassName>
00270 struct RegisterAnalysis : public RegisterPassBase {
00271   RegisterAnalysis(const char *PassArg, const char *Name,
00272                    bool CFGOnly = false)
00273   : RegisterPassBase(Name, PassArg, typeid(PassName), PassInfo::Analysis,
00274                      callDefaultCtor<PassName>) {
00275     if (CFGOnly) setOnlyUsesCFG();
00276   }
00277 };
00278 
00279 
00280 /// RegisterAnalysisGroup - Register a Pass as a member of an analysis _group_.
00281 /// Analysis groups are used to define an interface (which need not derive from
00282 /// Pass) that is required by passes to do their job.  Analysis Groups differ
00283 /// from normal analyses because any available implementation of the group will
00284 /// be used if it is available.
00285 ///
00286 /// If no analysis implementing the interface is available, a default
00287 /// implementation is created and added.  A pass registers itself as the default
00288 /// implementation by specifying 'true' as the third template argument of this
00289 /// class.
00290 ///
00291 /// In addition to registering itself as an analysis group member, a pass must
00292 /// register itself normally as well.  Passes may be members of multiple groups
00293 /// and may still be "required" specifically by name.
00294 ///
00295 /// The actual interface may also be registered as well (by not specifying the
00296 /// second template argument).  The interface should be registered to associate
00297 /// a nice name with the interface.
00298 ///
00299 class RegisterAGBase : public RegisterPassBase {
00300   PassInfo *InterfaceInfo;
00301   const PassInfo *ImplementationInfo;
00302   bool isDefaultImplementation;
00303 protected:
00304   RegisterAGBase(const std::type_info &Interface,
00305                  const std::type_info *Pass = 0,
00306                  bool isDefault = false);
00307   void setGroupName(const char *Name);
00308 public:
00309   ~RegisterAGBase();
00310 };
00311 
00312 
00313 template<typename Interface, typename DefaultImplementationPass = void,
00314          bool Default = false>
00315 struct RegisterAnalysisGroup : public RegisterAGBase {
00316   RegisterAnalysisGroup() : RegisterAGBase(typeid(Interface),
00317                                            &typeid(DefaultImplementationPass),
00318                                            Default) {
00319   }
00320 };
00321 
00322 /// Define a specialization of RegisterAnalysisGroup that is used to set the
00323 /// name for the analysis group.
00324 ///
00325 template<typename Interface>
00326 struct RegisterAnalysisGroup<Interface, void, false> : public RegisterAGBase {
00327   RegisterAnalysisGroup(const char *Name)
00328     : RegisterAGBase(typeid(Interface)) {
00329     setGroupName(Name);
00330   }
00331 };
00332 
00333 
00334 
00335 //===---------------------------------------------------------------------------
00336 /// PassRegistrationListener class - This class is meant to be derived from by
00337 /// clients that are interested in which passes get registered and unregistered
00338 /// at runtime (which can be because of the RegisterPass constructors being run
00339 /// as the program starts up, or may be because a shared object just got
00340 /// loaded).  Deriving from the PassRegistationListener class automatically
00341 /// registers your object to receive callbacks indicating when passes are loaded
00342 /// and removed.
00343 ///
00344 struct PassRegistrationListener {
00345 
00346   /// PassRegistrationListener ctor - Add the current object to the list of
00347   /// PassRegistrationListeners...
00348   PassRegistrationListener();
00349 
00350   /// dtor - Remove object from list of listeners...
00351   ///
00352   virtual ~PassRegistrationListener();
00353 
00354   /// Callback functions - These functions are invoked whenever a pass is loaded
00355   /// or removed from the current executable.
00356   ///
00357   virtual void passRegistered(const PassInfo *P) {}
00358   virtual void passUnregistered(const PassInfo *P) {}
00359 
00360   /// enumeratePasses - Iterate over the registered passes, calling the
00361   /// passEnumerate callback on each PassInfo object.
00362   ///
00363   void enumeratePasses();
00364 
00365   /// passEnumerate - Callback function invoked when someone calls
00366   /// enumeratePasses on this PassRegistrationListener object.
00367   ///
00368   virtual void passEnumerate(const PassInfo *P) {}
00369 };
00370 
00371 } // End llvm namespace
00372 
00373 #endif