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1 //===- llvm/PassSupport.h - Pass Support code -------------------*- 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 stuff that is used to define and "use" Passes.  This file
11 // is automatically #included by Pass.h, so:
12 //
13 //           NO .CPP FILES SHOULD INCLUDE THIS FILE DIRECTLY
14 //
15 // Instead, #include Pass.h.
16 //
17 // This file defines Pass registration code and classes used for it.
18 //
19 //===----------------------------------------------------------------------===//
20 
21 #ifndef LLVM_PASS_SUPPORT_H
22 #define LLVM_PASS_SUPPORT_H
23 
24 #include "Pass.h"
25 #include "llvm/PassRegistry.h"
26 #include "llvm/InitializePasses.h"
27 #include "llvm/Support/Atomic.h"
28 #include <vector>
29 
30 namespace llvm {
31 
32 //===---------------------------------------------------------------------------
33 /// PassInfo class - An instance of this class exists for every pass known by
34 /// the system, and can be obtained from a live Pass by calling its
35 /// getPassInfo() method.  These objects are set up by the RegisterPass<>
36 /// template, defined below.
37 ///
38 class PassInfo {
39 public:
40   typedef Pass* (*NormalCtor_t)();
41 
42 private:
43   const char      *const PassName;     // Nice name for Pass
44   const char      *const PassArgument; // Command Line argument to run this pass
45   const void *PassID;
46   const bool IsCFGOnlyPass;            // Pass only looks at the CFG.
47   const bool IsAnalysis;               // True if an analysis pass.
48   const bool IsAnalysisGroup;          // True if an analysis group.
49   std::vector<const PassInfo*> ItfImpl;// Interfaces implemented by this pass
50 
51   NormalCtor_t NormalCtor;
52 
53 public:
54   /// PassInfo ctor - Do not call this directly, this should only be invoked
55   /// through RegisterPass.
PassInfo(const char * name,const char * arg,const void * pi,NormalCtor_t normal,bool isCFGOnly,bool is_analysis)56   PassInfo(const char *name, const char *arg, const void *pi,
57            NormalCtor_t normal, bool isCFGOnly, bool is_analysis)
58     : PassName(name), PassArgument(arg), PassID(pi),
59       IsCFGOnlyPass(isCFGOnly),
60       IsAnalysis(is_analysis), IsAnalysisGroup(false), NormalCtor(normal) { }
61   /// PassInfo ctor - Do not call this directly, this should only be invoked
62   /// through RegisterPass. This version is for use by analysis groups; it
63   /// does not auto-register the pass.
PassInfo(const char * name,const void * pi)64   PassInfo(const char *name, const void *pi)
65     : PassName(name), PassArgument(""), PassID(pi),
66       IsCFGOnlyPass(false),
67       IsAnalysis(false), IsAnalysisGroup(true), NormalCtor(0) { }
68 
69   /// getPassName - Return the friendly name for the pass, never returns null
70   ///
getPassName()71   const char *getPassName() const { return PassName; }
72 
73   /// getPassArgument - Return the command line option that may be passed to
74   /// 'opt' that will cause this pass to be run.  This will return null if there
75   /// is no argument.
76   ///
getPassArgument()77   const char *getPassArgument() const { return PassArgument; }
78 
79   /// getTypeInfo - Return the id object for the pass...
80   /// TODO : Rename
getTypeInfo()81   const void *getTypeInfo() const { return PassID; }
82 
83   /// Return true if this PassID implements the specified ID pointer.
isPassID(const void * IDPtr)84   bool isPassID(const void *IDPtr) const {
85     return PassID == IDPtr;
86   }
87 
88   /// isAnalysisGroup - Return true if this is an analysis group, not a normal
89   /// pass.
90   ///
isAnalysisGroup()91   bool isAnalysisGroup() const { return IsAnalysisGroup; }
isAnalysis()92   bool isAnalysis() const { return IsAnalysis; }
93 
94   /// isCFGOnlyPass - return true if this pass only looks at the CFG for the
95   /// function.
isCFGOnlyPass()96   bool isCFGOnlyPass() const { return IsCFGOnlyPass; }
97 
98   /// getNormalCtor - Return a pointer to a function, that when called, creates
99   /// an instance of the pass and returns it.  This pointer may be null if there
100   /// is no default constructor for the pass.
101   ///
getNormalCtor()102   NormalCtor_t getNormalCtor() const {
103     return NormalCtor;
104   }
setNormalCtor(NormalCtor_t Ctor)105   void setNormalCtor(NormalCtor_t Ctor) {
106     NormalCtor = Ctor;
107   }
108 
109   /// createPass() - Use this method to create an instance of this pass.
110   Pass *createPass() const;
111 
112   /// addInterfaceImplemented - This method is called when this pass is
113   /// registered as a member of an analysis group with the RegisterAnalysisGroup
114   /// template.
115   ///
addInterfaceImplemented(const PassInfo * ItfPI)116   void addInterfaceImplemented(const PassInfo *ItfPI) {
117     ItfImpl.push_back(ItfPI);
118   }
119 
120   /// getInterfacesImplemented - Return a list of all of the analysis group
121   /// interfaces implemented by this pass.
122   ///
getInterfacesImplemented()123   const std::vector<const PassInfo*> &getInterfacesImplemented() const {
124     return ItfImpl;
125   }
126 
127 private:
128   void operator=(const PassInfo &); // do not implement
129   PassInfo(const PassInfo &);       // do not implement
130 };
131 
132 #define CALL_ONCE_INITIALIZATION(function) \
133   static volatile sys::cas_flag initialized = 0; \
134   sys::cas_flag old_val = sys::CompareAndSwap(&initialized, 1, 0); \
135   if (old_val == 0) { \
136     function(Registry); \
137     sys::MemoryFence(); \
138     initialized = 2; \
139   } else { \
140     sys::cas_flag tmp = initialized; \
141     sys::MemoryFence(); \
142     while (tmp != 2) { \
143       tmp = initialized; \
144       sys::MemoryFence(); \
145     } \
146   }
147 
148 #define INITIALIZE_PASS(passName, arg, name, cfg, analysis) \
149   static void* initialize##passName##PassOnce(PassRegistry &Registry) { \
150     PassInfo *PI = new PassInfo(name, arg, & passName ::ID, \
151       PassInfo::NormalCtor_t(callDefaultCtor< passName >), cfg, analysis); \
152     Registry.registerPass(*PI, true); \
153     return PI; \
154   } \
155   void llvm::initialize##passName##Pass(PassRegistry &Registry) { \
156     CALL_ONCE_INITIALIZATION(initialize##passName##PassOnce) \
157   }
158 
159 #define INITIALIZE_PASS_BEGIN(passName, arg, name, cfg, analysis) \
160   static void* initialize##passName##PassOnce(PassRegistry &Registry) {
161 
162 #define INITIALIZE_PASS_DEPENDENCY(depName) \
163     initialize##depName##Pass(Registry);
164 #define INITIALIZE_AG_DEPENDENCY(depName) \
165     initialize##depName##AnalysisGroup(Registry);
166 
167 #define INITIALIZE_PASS_END(passName, arg, name, cfg, analysis) \
168     PassInfo *PI = new PassInfo(name, arg, & passName ::ID, \
169       PassInfo::NormalCtor_t(callDefaultCtor< passName >), cfg, analysis); \
170     Registry.registerPass(*PI, true); \
171     return PI; \
172   } \
173   void llvm::initialize##passName##Pass(PassRegistry &Registry) { \
174     CALL_ONCE_INITIALIZATION(initialize##passName##PassOnce) \
175   }
176 
177 template<typename PassName>
callDefaultCtor()178 Pass *callDefaultCtor() { return new PassName(); }
179 
180 //===---------------------------------------------------------------------------
181 /// RegisterPass<t> template - This template class is used to notify the system
182 /// that a Pass is available for use, and registers it into the internal
183 /// database maintained by the PassManager.  Unless this template is used, opt,
184 /// for example will not be able to see the pass and attempts to create the pass
185 /// will fail. This template is used in the follow manner (at global scope, in
186 /// your .cpp file):
187 ///
188 /// static RegisterPass<YourPassClassName> tmp("passopt", "My Pass Name");
189 ///
190 /// This statement will cause your pass to be created by calling the default
191 /// constructor exposed by the pass.  If you have a different constructor that
192 /// must be called, create a global constructor function (which takes the
193 /// arguments you need and returns a Pass*) and register your pass like this:
194 ///
195 /// static RegisterPass<PassClassName> tmp("passopt", "My Name");
196 ///
197 template<typename passName>
198 struct RegisterPass : public PassInfo {
199 
200   // Register Pass using default constructor...
201   RegisterPass(const char *PassArg, const char *Name, bool CFGOnly = false,
202                bool is_analysis = false)
203     : PassInfo(Name, PassArg, &passName::ID,
204                PassInfo::NormalCtor_t(callDefaultCtor<passName>),
205                CFGOnly, is_analysis) {
206     PassRegistry::getPassRegistry()->registerPass(*this);
207   }
208 };
209 
210 
211 /// RegisterAnalysisGroup - Register a Pass as a member of an analysis _group_.
212 /// Analysis groups are used to define an interface (which need not derive from
213 /// Pass) that is required by passes to do their job.  Analysis Groups differ
214 /// from normal analyses because any available implementation of the group will
215 /// be used if it is available.
216 ///
217 /// If no analysis implementing the interface is available, a default
218 /// implementation is created and added.  A pass registers itself as the default
219 /// implementation by specifying 'true' as the second template argument of this
220 /// class.
221 ///
222 /// In addition to registering itself as an analysis group member, a pass must
223 /// register itself normally as well.  Passes may be members of multiple groups
224 /// and may still be "required" specifically by name.
225 ///
226 /// The actual interface may also be registered as well (by not specifying the
227 /// second template argument).  The interface should be registered to associate
228 /// a nice name with the interface.
229 ///
230 class RegisterAGBase : public PassInfo {
231 public:
232   RegisterAGBase(const char *Name,
233                  const void *InterfaceID,
234                  const void *PassID = 0,
235                  bool isDefault = false);
236 };
237 
238 template<typename Interface, bool Default = false>
239 struct RegisterAnalysisGroup : public RegisterAGBase {
RegisterAnalysisGroupRegisterAnalysisGroup240   explicit RegisterAnalysisGroup(PassInfo &RPB)
241     : RegisterAGBase(RPB.getPassName(),
242                      &Interface::ID, RPB.getTypeInfo(),
243                      Default) {
244   }
245 
RegisterAnalysisGroupRegisterAnalysisGroup246   explicit RegisterAnalysisGroup(const char *Name)
247     : RegisterAGBase(Name, &Interface::ID) {
248   }
249 };
250 
251 #define INITIALIZE_ANALYSIS_GROUP(agName, name, defaultPass) \
252   static void* initialize##agName##AnalysisGroupOnce(PassRegistry &Registry) { \
253     initialize##defaultPass##Pass(Registry); \
254     PassInfo *AI = new PassInfo(name, & agName :: ID); \
255     Registry.registerAnalysisGroup(& agName ::ID, 0, *AI, false, true); \
256     return AI; \
257   } \
258   void llvm::initialize##agName##AnalysisGroup(PassRegistry &Registry) { \
259     CALL_ONCE_INITIALIZATION(initialize##agName##AnalysisGroupOnce) \
260   }
261 
262 
263 #define INITIALIZE_AG_PASS(passName, agName, arg, name, cfg, analysis, def) \
264   static void* initialize##passName##PassOnce(PassRegistry &Registry) { \
265     if (!def) initialize##agName##AnalysisGroup(Registry); \
266     PassInfo *PI = new PassInfo(name, arg, & passName ::ID, \
267       PassInfo::NormalCtor_t(callDefaultCtor< passName >), cfg, analysis); \
268     Registry.registerPass(*PI, true); \
269     \
270     PassInfo *AI = new PassInfo(name, & agName :: ID); \
271     Registry.registerAnalysisGroup(& agName ::ID, & passName ::ID, \
272                                    *AI, def, true); \
273     return AI; \
274   } \
275   void llvm::initialize##passName##Pass(PassRegistry &Registry) { \
276     CALL_ONCE_INITIALIZATION(initialize##passName##PassOnce) \
277   }
278 
279 
280 #define INITIALIZE_AG_PASS_BEGIN(passName, agName, arg, n, cfg, analysis, def) \
281   static void* initialize##passName##PassOnce(PassRegistry &Registry) { \
282     if (!def) initialize##agName##AnalysisGroup(Registry);
283 
284 #define INITIALIZE_AG_PASS_END(passName, agName, arg, n, cfg, analysis, def) \
285     PassInfo *PI = new PassInfo(n, arg, & passName ::ID, \
286       PassInfo::NormalCtor_t(callDefaultCtor< passName >), cfg, analysis); \
287     Registry.registerPass(*PI, true); \
288     \
289     PassInfo *AI = new PassInfo(n, & agName :: ID); \
290     Registry.registerAnalysisGroup(& agName ::ID, & passName ::ID, \
291                                    *AI, def, true); \
292     return AI; \
293   } \
294   void llvm::initialize##passName##Pass(PassRegistry &Registry) { \
295     CALL_ONCE_INITIALIZATION(initialize##passName##PassOnce) \
296   }
297 
298 //===---------------------------------------------------------------------------
299 /// PassRegistrationListener class - This class is meant to be derived from by
300 /// clients that are interested in which passes get registered and unregistered
301 /// at runtime (which can be because of the RegisterPass constructors being run
302 /// as the program starts up, or may be because a shared object just got
303 /// loaded).  Deriving from the PassRegistationListener class automatically
304 /// registers your object to receive callbacks indicating when passes are loaded
305 /// and removed.
306 ///
307 struct PassRegistrationListener {
308 
309   /// PassRegistrationListener ctor - Add the current object to the list of
310   /// PassRegistrationListeners...
311   PassRegistrationListener();
312 
313   /// dtor - Remove object from list of listeners...
314   ///
315   virtual ~PassRegistrationListener();
316 
317   /// Callback functions - These functions are invoked whenever a pass is loaded
318   /// or removed from the current executable.
319   ///
passRegisteredPassRegistrationListener320   virtual void passRegistered(const PassInfo *) {}
321 
322   /// enumeratePasses - Iterate over the registered passes, calling the
323   /// passEnumerate callback on each PassInfo object.
324   ///
325   void enumeratePasses();
326 
327   /// passEnumerate - Callback function invoked when someone calls
328   /// enumeratePasses on this PassRegistrationListener object.
329   ///
passEnumeratePassRegistrationListener330   virtual void passEnumerate(const PassInfo *) {}
331 };
332 
333 
334 } // End llvm namespace
335 
336 #endif
337