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
22 // No need to include Pass.h, we are being included by it!
24 //===----------------------------------------------------------------------===//
25 // AnalysisUsage - Represent the analysis usage information of a pass. This
26 // tracks analyses that the pass REQUIRES (must available when the pass runs),
27 // and analyses that the pass PRESERVES (the pass does not invalidate the
28 // results of these analyses). This information is provided by a pass to the
29 // Pass infrastructure through the getAnalysisUsage virtual function.
32 // Sets of analyses required and preserved by a pass
33 std::vector<AnalysisID> Required, Preserved;
36 AnalysisUsage() : PreservesAll(false) {}
38 // addRequired - Add the specified ID to the required set of the usage info
41 AnalysisUsage &addRequiredID(AnalysisID ID) {
42 Required.push_back(ID);
45 template<class PassClass>
46 AnalysisUsage &addRequired() {
47 assert(Pass::getClassPassInfo<PassClass>() && "Pass class not registered!");
48 Required.push_back(Pass::getClassPassInfo<PassClass>());
52 // addPreserved - Add the specified ID to the set of analyses preserved by
55 AnalysisUsage &addPreservedID(AnalysisID ID) {
56 Preserved.push_back(ID);
60 template<class PassClass>
61 AnalysisUsage &addPreserved() {
62 assert(Pass::getClassPassInfo<PassClass>() && "Pass class not registered!");
63 Preserved.push_back(Pass::getClassPassInfo<PassClass>());
67 // setPreservesAll - Set by analyses that do not transform their input at all
68 void setPreservesAll() { PreservesAll = true; }
69 bool getPreservesAll() const { return PreservesAll; }
71 /// setPreservesCFG - This function should be called by the pass, iff they do
74 /// 1. Add or remove basic blocks from the function
75 /// 2. Modify terminator instructions in any way.
77 /// This function annotates the AnalysisUsage info object to say that analyses
78 /// that only depend on the CFG are preserved by this pass.
80 void setPreservesCFG();
82 const std::vector<AnalysisID> &getRequiredSet() const { return Required; }
83 const std::vector<AnalysisID> &getPreservedSet() const { return Preserved; }
88 //===----------------------------------------------------------------------===//
89 // AnalysisResolver - Simple interface implemented by PassManager objects that
90 // is used to pull analysis information out of them.
92 struct AnalysisResolver {
93 virtual Pass *getAnalysisOrNullUp(AnalysisID ID) const = 0;
94 virtual Pass *getAnalysisOrNullDown(AnalysisID ID) const = 0;
95 virtual void addPass(ImmutablePass *IP, AnalysisUsage &AU) = 0;
96 Pass *getAnalysis(AnalysisID ID) const {
97 Pass *Result = getAnalysisOrNullUp(ID);
98 assert(Result && "Pass has an incorrect analysis uses set!");
102 // getAnalysisToUpdate - Return an analysis result or null if it doesn't exist
103 Pass *getAnalysisToUpdate(AnalysisID ID) const {
104 return getAnalysisOrNullUp(ID);
107 // Methods for introspecting into pass manager objects...
108 virtual unsigned getDepth() const = 0;
109 virtual unsigned getNumContainedPasses() const = 0;
110 virtual const Pass *getContainedPass(unsigned N) const = 0;
112 virtual void markPassUsed(AnalysisID P, Pass *User) = 0;
114 void startPass(Pass *P) {}
115 void endPass(Pass *P) {}
117 void setAnalysisResolver(Pass *P, AnalysisResolver *AR);
120 /// getAnalysisToUpdate<AnalysisType>() - This function is used by subclasses
121 /// to get to the analysis information that might be around that needs to be
122 /// updated. This is different than getAnalysis in that it can fail (ie the
123 /// analysis results haven't been computed), so should only be used if you
124 /// provide the capability to update an analysis that exists. This method is
125 /// often used by transformation APIs to update analysis results for a pass
126 /// automatically as the transform is performed.
128 template<typename AnalysisType>
129 AnalysisType *Pass::getAnalysisToUpdate() const {
130 assert(Resolver && "Pass not resident in a PassManager object!");
131 const PassInfo *PI = getClassPassInfo<AnalysisType>();
132 if (PI == 0) return 0;
133 return dynamic_cast<AnalysisType*>(Resolver->getAnalysisToUpdate(PI));