1 //===- llvm/Pass.h - Base class for Passes ----------------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines a base class that indicates that a specified class is a
11 // transformation pass implementation.
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.
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.
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.
27 //===----------------------------------------------------------------------===//
32 #include "llvm/Support/Streams.h"
39 //Use new Pass Manager. Disable old Pass Manager.
40 //#define USE_OLD_PASSMANAGER 1
51 template<class Trait> class PassManagerT;
52 class BasicBlockPassManager;
53 class FunctionPassManagerT;
54 class ModulePassManager;
55 struct AnalysisResolver;
56 class AnalysisResolver_New;
58 // AnalysisID - Use the PassInfo to identify a pass...
59 typedef const PassInfo* AnalysisID;
61 //===----------------------------------------------------------------------===//
62 /// Pass interface - Implemented by all 'passes'. Subclass this if you are an
63 /// interprocedural optimization or you do not fit into any of the more
64 /// constrained passes described below.
67 friend struct AnalysisResolver;
68 AnalysisResolver *Resolver; // AnalysisResolver this pass is owned by...
69 AnalysisResolver_New *Resolver_New; // Used to resolve analysis
70 const PassInfo *PassInfoCache;
72 // AnalysisImpls - This keeps track of which passes implement the interfaces
73 // that are required by the current pass (to implement getAnalysis()).
75 std::vector<std::pair<const PassInfo*, Pass*> > AnalysisImpls;
77 void operator=(const Pass&); // DO NOT IMPLEMENT
78 Pass(const Pass &); // DO NOT IMPLEMENT
80 Pass() : Resolver(0), Resolver_New(0), PassInfoCache(0) {}
81 virtual ~Pass() {} // Destructor is virtual so we can be subclassed
83 /// getPassName - Return a nice clean name for a pass. This usually
84 /// implemented in terms of the name that is registered by one of the
85 /// Registration templates, but can be overloaded directly, and if nothing
86 /// else is available, C++ RTTI will be consulted to get a SOMEWHAT
87 /// intelligible name for the pass.
89 virtual const char *getPassName() const;
91 /// getPassInfo - Return the PassInfo data structure that corresponds to this
92 /// pass... If the pass has not been registered, this will return null.
94 const PassInfo *getPassInfo() const;
96 /// runPass - Run this pass, returning true if a modification was made to the
97 /// module argument. This should be implemented by all concrete subclasses.
99 virtual bool runPass(Module &M) { return false; }
100 virtual bool runPass(BasicBlock&) { return false; }
102 /// print - Print out the internal state of the pass. This is called by
103 /// Analyze to print out the contents of an analysis. Otherwise it is not
104 /// necessary to implement this method. Beware that the module pointer MAY be
105 /// null. This automatically forwards to a virtual function that does not
106 /// provide the Module* in case the analysis doesn't need it it can just be
109 virtual void print(std::ostream &O, const Module *M) const;
110 void print(std::ostream *O, const Module *M) const { if (O) print(*O, M); }
111 void dump() const; // dump - call print(std::cerr, 0);
113 // Access AnalysisResolver_New
114 inline void setResolver(AnalysisResolver_New *AR) { Resolver_New = AR; }
115 inline AnalysisResolver_New *getResolver() { return Resolver_New; }
117 /// getAnalysisUsage - This function should be overriden by passes that need
118 /// analysis information to do their job. If a pass specifies that it uses a
119 /// particular analysis result to this function, it can then use the
120 /// getAnalysis<AnalysisType>() function, below.
122 virtual void getAnalysisUsage(AnalysisUsage &Info) const {
123 // By default, no analysis results are used, all are invalidated.
126 /// releaseMemory() - This member can be implemented by a pass if it wants to
127 /// be able to release its memory when it is no longer needed. The default
128 /// behavior of passes is to hold onto memory for the entire duration of their
129 /// lifetime (which is the entire compile time). For pipelined passes, this
130 /// is not a big deal because that memory gets recycled every time the pass is
131 /// invoked on another program unit. For IP passes, it is more important to
132 /// free memory when it is unused.
134 /// Optionally implement this function to release pass memory when it is no
137 virtual void releaseMemory() {}
139 // dumpPassStructure - Implement the -debug-passes=PassStructure option
140 virtual void dumpPassStructure(unsigned Offset = 0);
143 // getPassInfo - Static method to get the pass information from a class name.
144 template<typename AnalysisClass>
145 static const PassInfo *getClassPassInfo() {
146 return lookupPassInfo(typeid(AnalysisClass));
149 // lookupPassInfo - Return the pass info object for the specified pass class,
150 // or null if it is not known.
151 static const PassInfo *lookupPassInfo(const std::type_info &TI);
153 /// getAnalysisToUpdate<AnalysisType>() - This function is used by subclasses
154 /// to get to the analysis information that might be around that needs to be
155 /// updated. This is different than getAnalysis in that it can fail (ie the
156 /// analysis results haven't been computed), so should only be used if you
157 /// provide the capability to update an analysis that exists. This method is
158 /// often used by transformation APIs to update analysis results for a pass
159 /// automatically as the transform is performed.
161 template<typename AnalysisType>
162 AnalysisType *getAnalysisToUpdate() const; // Defined in PassAnalysisSupport.h
164 /// mustPreserveAnalysisID - This method serves the same function as
165 /// getAnalysisToUpdate, but works if you just have an AnalysisID. This
166 /// obviously cannot give you a properly typed instance of the class if you
167 /// don't have the class name available (use getAnalysisToUpdate if you do),
168 /// but it can tell you if you need to preserve the pass at least.
170 bool mustPreserveAnalysisID(const PassInfo *AnalysisID) const;
172 /// getAnalysis<AnalysisType>() - This function is used by subclasses to get
173 /// to the analysis information that they claim to use by overriding the
174 /// getAnalysisUsage function.
176 template<typename AnalysisType>
177 AnalysisType &getAnalysis() const; // Defined in PassAnalysisSupport.h
179 template<typename AnalysisType>
180 AnalysisType &getAnalysisID(const PassInfo *PI) const;
183 template<typename Trait> friend class PassManagerT;
184 friend class ModulePassManager;
185 friend class FunctionPassManagerT;
186 friend class BasicBlockPassManager;
189 inline std::ostream &operator<<(std::ostream &OS, const Pass &P) {
190 P.print(OS, 0); return OS;
193 //===----------------------------------------------------------------------===//
194 /// ModulePass class - This class is used to implement unstructured
195 /// interprocedural optimizations and analyses. ModulePasses may do anything
196 /// they want to the program.
198 class ModulePass : public Pass {
200 /// runOnModule - Virtual method overriden by subclasses to process the module
201 /// being operated on.
202 virtual bool runOnModule(Module &M) = 0;
204 virtual bool runPass(Module &M) { return runOnModule(M); }
205 virtual bool runPass(BasicBlock&) { return false; }
207 #ifdef USE_OLD_PASSMANAGER
208 virtual void addToPassManager(ModulePassManager *PM, AnalysisUsage &AU);
210 // Force out-of-line virtual method.
211 virtual ~ModulePass();
216 //===----------------------------------------------------------------------===//
217 /// ImmutablePass class - This class is used to provide information that does
218 /// not need to be run. This is useful for things like target information and
219 /// "basic" versions of AnalysisGroups.
221 class ImmutablePass : public ModulePass {
223 /// initializePass - This method may be overriden by immutable passes to allow
224 /// them to perform various initialization actions they require. This is
225 /// primarily because an ImmutablePass can "require" another ImmutablePass,
226 /// and if it does, the overloaded version of initializePass may get access to
227 /// these passes with getAnalysis<>.
229 virtual void initializePass() {}
231 /// ImmutablePasses are never run.
233 virtual bool runOnModule(Module &M) { return false; }
235 #ifdef USE_OLD_PASSMANAGER
237 template<typename Trait> friend class PassManagerT;
238 friend class ModulePassManager;
239 virtual void addToPassManager(ModulePassManager *PM, AnalysisUsage &AU);
241 // Force out-of-line virtual method.
242 virtual ~ImmutablePass();
246 //===----------------------------------------------------------------------===//
247 /// FunctionPass class - This class is used to implement most global
248 /// optimizations. Optimizations should subclass this class if they meet the
249 /// following constraints:
251 /// 1. Optimizations are organized globally, i.e., a function at a time
252 /// 2. Optimizing a function does not cause the addition or removal of any
253 /// functions in the module
255 class FunctionPass : public ModulePass {
257 /// doInitialization - Virtual method overridden by subclasses to do
258 /// any necessary per-module initialization.
260 virtual bool doInitialization(Module &M) { return false; }
262 /// runOnFunction - Virtual method overriden by subclasses to do the
263 /// per-function processing of the pass.
265 virtual bool runOnFunction(Function &F) = 0;
267 /// doFinalization - Virtual method overriden by subclasses to do any post
268 /// processing needed after all passes have run.
270 virtual bool doFinalization(Module &M) { return false; }
272 /// runOnModule - On a module, we run this pass by initializing,
273 /// ronOnFunction'ing once for every function in the module, then by
276 virtual bool runOnModule(Module &M);
278 /// run - On a function, we simply initialize, run the function, then
281 bool run(Function &F);
283 #ifdef USE_OLD_PASSMANAGER
285 template<typename Trait> friend class PassManagerT;
286 friend class ModulePassManager;
287 friend class FunctionPassManagerT;
288 friend class BasicBlockPassManager;
289 virtual void addToPassManager(ModulePassManager *PM, AnalysisUsage &AU);
290 virtual void addToPassManager(FunctionPassManagerT *PM, AnalysisUsage &AU);
296 //===----------------------------------------------------------------------===//
297 /// BasicBlockPass class - This class is used to implement most local
298 /// optimizations. Optimizations should subclass this class if they
299 /// meet the following constraints:
300 /// 1. Optimizations are local, operating on either a basic block or
301 /// instruction at a time.
302 /// 2. Optimizations do not modify the CFG of the contained function, or any
303 /// other basic block in the function.
304 /// 3. Optimizations conform to all of the constraints of FunctionPasses.
306 class BasicBlockPass : public FunctionPass {
308 /// doInitialization - Virtual method overridden by subclasses to do
309 /// any necessary per-module initialization.
311 virtual bool doInitialization(Module &M) { return false; }
313 /// doInitialization - Virtual method overridden by BasicBlockPass subclasses
314 /// to do any necessary per-function initialization.
316 virtual bool doInitialization(Function &F) { return false; }
318 /// runOnBasicBlock - Virtual method overriden by subclasses to do the
319 /// per-basicblock processing of the pass.
321 virtual bool runOnBasicBlock(BasicBlock &BB) = 0;
323 /// doFinalization - Virtual method overriden by BasicBlockPass subclasses to
324 /// do any post processing needed after all passes have run.
326 virtual bool doFinalization(Function &F) { return false; }
328 /// doFinalization - Virtual method overriden by subclasses to do any post
329 /// processing needed after all passes have run.
331 virtual bool doFinalization(Module &M) { return false; }
334 // To run this pass on a function, we simply call runOnBasicBlock once for
337 bool runOnFunction(Function &F);
339 /// To run directly on the basic block, we initialize, runOnBasicBlock, then
342 virtual bool runPass(Module &M) { return false; }
343 virtual bool runPass(BasicBlock &BB);
345 #ifdef USE_OLD_PASSMANAGER
347 template<typename Trait> friend class PassManagerT;
348 friend class FunctionPassManagerT;
349 friend class BasicBlockPassManager;
350 virtual void addToPassManager(ModulePassManager *PM, AnalysisUsage &AU) {
351 FunctionPass::addToPassManager(PM, AU);
353 virtual void addToPassManager(FunctionPassManagerT *PM, AnalysisUsage &AU);
354 virtual void addToPassManager(BasicBlockPassManager *PM,AnalysisUsage &AU);
358 /// If the user specifies the -time-passes argument on an LLVM tool command line
359 /// then the value of this boolean will be true, otherwise false.
360 /// @brief This is the storage for the -time-passes option.
361 extern bool TimePassesIsEnabled;
363 } // End llvm namespace
365 // Include support files that contain important APIs commonly used by Passes,
366 // but that we want to separate out to make it easier to read the header files.
368 #include "llvm/PassSupport.h"
369 #include "llvm/PassAnalysisSupport.h"