1 //===- llvm/PassAnalysisSupport.h - Analysis Pass Support code --*- 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 stuff that is used to define and "use" Analysis Passes.
11 // This file is automatically #included by Pass.h, so:
13 // NO .CPP FILES SHOULD INCLUDE THIS FILE DIRECTLY
15 // Instead, #include Pass.h
17 //===----------------------------------------------------------------------===//
19 #ifndef LLVM_PASS_ANALYSIS_SUPPORT_H
20 #define LLVM_PASS_ANALYSIS_SUPPORT_H
26 // No need to include Pass.h, we are being included by it!
28 //===----------------------------------------------------------------------===//
29 // AnalysisUsage - Represent the analysis usage information of a pass. This
30 // tracks analyses that the pass REQUIRES (must be available when the pass
31 // runs), REQUIRES TRANSITIVE (must be available throughout the lifetime of the
32 // pass), and analyses that the pass PRESERVES (the pass does not invalidate the
33 // results of these analyses). This information is provided by a pass to the
34 // Pass infrastructure through the getAnalysisUsage virtual function.
37 // Sets of analyses required and preserved by a pass
38 std::vector<AnalysisID> Required, RequiredTransitive, Preserved;
41 AnalysisUsage() : PreservesAll(false) {}
43 // addRequired - Add the specified ID to the required set of the usage info
46 AnalysisUsage &addRequiredID(AnalysisID ID) {
47 Required.push_back(ID);
50 template<class PassClass>
51 AnalysisUsage &addRequired() {
52 assert(Pass::getClassPassInfo<PassClass>() && "Pass class not registered!");
53 Required.push_back(Pass::getClassPassInfo<PassClass>());
57 template<class PassClass>
58 AnalysisUsage &addRequiredTransitive() {
59 AnalysisID ID = Pass::getClassPassInfo<PassClass>();
60 assert(ID && "Pass class not registered!");
61 Required.push_back(ID);
62 RequiredTransitive.push_back(ID);
66 // addPreserved - Add the specified ID to the set of analyses preserved by
69 AnalysisUsage &addPreservedID(AnalysisID ID) {
70 Preserved.push_back(ID);
74 template<class PassClass>
75 AnalysisUsage &addPreserved() {
76 assert(Pass::getClassPassInfo<PassClass>() && "Pass class not registered!");
77 Preserved.push_back(Pass::getClassPassInfo<PassClass>());
81 // setPreservesAll - Set by analyses that do not transform their input at all
82 void setPreservesAll() { PreservesAll = true; }
83 bool getPreservesAll() const { return PreservesAll; }
85 /// setPreservesCFG - This function should be called by the pass, iff they do
88 /// 1. Add or remove basic blocks from the function
89 /// 2. Modify terminator instructions in any way.
91 /// This function annotates the AnalysisUsage info object to say that analyses
92 /// that only depend on the CFG are preserved by this pass.
94 void setPreservesCFG();
96 const std::vector<AnalysisID> &getRequiredSet() const { return Required; }
97 const std::vector<AnalysisID> &getRequiredTransitiveSet() const {
98 return RequiredTransitive;
100 const std::vector<AnalysisID> &getPreservedSet() const { return Preserved; }
105 //===----------------------------------------------------------------------===//
106 // AnalysisResolver - Simple interface implemented by PassManager objects that
107 // is used to pull analysis information out of them.
109 struct AnalysisResolver {
110 virtual ~AnalysisResolver();
111 virtual Pass *getAnalysisOrNullUp(AnalysisID ID) const = 0;
112 virtual Pass *getAnalysisOrNullDown(AnalysisID ID) const = 0;
113 virtual void addPass(ImmutablePass *IP, AnalysisUsage &AU) = 0;
114 Pass *getAnalysis(AnalysisID ID) const {
115 Pass *Result = getAnalysisOrNullUp(ID);
116 assert(Result && "Pass has an incorrect analysis uses set!");
120 // getAnalysisToUpdate - Return an analysis result or null if it doesn't exist
121 Pass *getAnalysisToUpdate(AnalysisID ID) const {
122 return getAnalysisOrNullUp(ID);
125 // Methods for introspecting into pass manager objects...
126 virtual unsigned getDepth() const = 0;
127 virtual unsigned getNumContainedPasses() const = 0;
128 virtual const Pass *getContainedPass(unsigned N) const = 0;
130 virtual void markPassUsed(AnalysisID P, Pass *User) = 0;
132 void startPass(Pass *P) {}
133 void endPass(Pass *P) {}
135 void setAnalysisResolver(Pass *P, AnalysisResolver *AR);
138 /// getAnalysisToUpdate<AnalysisType>() - This function is used by subclasses
139 /// to get to the analysis information that might be around that needs to be
140 /// updated. This is different than getAnalysis in that it can fail (ie the
141 /// analysis results haven't been computed), so should only be used if you
142 /// provide the capability to update an analysis that exists. This method is
143 /// often used by transformation APIs to update analysis results for a pass
144 /// automatically as the transform is performed.
146 template<typename AnalysisType>
147 AnalysisType *Pass::getAnalysisToUpdate() const {
148 assert(Resolver && "Pass not resident in a PassManager object!");
149 const PassInfo *PI = getClassPassInfo<AnalysisType>();
150 if (PI == 0) return 0;
151 return dynamic_cast<AnalysisType*>(Resolver->getAnalysisToUpdate(PI));
154 } // End llvm namespace