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
24 // No need to include Pass.h, we are being included by it!
26 //===----------------------------------------------------------------------===//
27 // AnalysisUsage - Represent the analysis usage information of a pass. This
28 // tracks analyses that the pass REQUIRES (must available when the pass runs),
29 // and analyses that the pass PRESERVES (the pass does not invalidate the
30 // results of these analyses). This information is provided by a pass to the
31 // Pass infrastructure through the getAnalysisUsage virtual function.
34 // Sets of analyses required and preserved by a pass
35 std::vector<AnalysisID> Required, Preserved;
38 AnalysisUsage() : PreservesAll(false) {}
40 // addRequired - Add the specified ID to the required set of the usage info
43 AnalysisUsage &addRequiredID(AnalysisID ID) {
44 Required.push_back(ID);
47 template<class PassClass>
48 AnalysisUsage &addRequired() {
49 assert(Pass::getClassPassInfo<PassClass>() && "Pass class not registered!");
50 Required.push_back(Pass::getClassPassInfo<PassClass>());
54 // addPreserved - Add the specified ID to the set of analyses preserved by
57 AnalysisUsage &addPreservedID(AnalysisID ID) {
58 Preserved.push_back(ID);
62 template<class PassClass>
63 AnalysisUsage &addPreserved() {
64 assert(Pass::getClassPassInfo<PassClass>() && "Pass class not registered!");
65 Preserved.push_back(Pass::getClassPassInfo<PassClass>());
69 // setPreservesAll - Set by analyses that do not transform their input at all
70 void setPreservesAll() { PreservesAll = true; }
71 bool getPreservesAll() const { return PreservesAll; }
73 /// setPreservesCFG - This function should be called by the pass, iff they do
76 /// 1. Add or remove basic blocks from the function
77 /// 2. Modify terminator instructions in any way.
79 /// This function annotates the AnalysisUsage info object to say that analyses
80 /// that only depend on the CFG are preserved by this pass.
82 void setPreservesCFG();
84 const std::vector<AnalysisID> &getRequiredSet() const { return Required; }
85 const std::vector<AnalysisID> &getPreservedSet() const { return Preserved; }
90 //===----------------------------------------------------------------------===//
91 // AnalysisResolver - Simple interface implemented by PassManager objects that
92 // is used to pull analysis information out of them.
94 struct AnalysisResolver {
95 virtual Pass *getAnalysisOrNullUp(AnalysisID ID) const = 0;
96 virtual Pass *getAnalysisOrNullDown(AnalysisID ID) const = 0;
97 virtual void addPass(ImmutablePass *IP, AnalysisUsage &AU) = 0;
98 Pass *getAnalysis(AnalysisID ID) const {
99 Pass *Result = getAnalysisOrNullUp(ID);
100 assert(Result && "Pass has an incorrect analysis uses set!");
104 // getAnalysisToUpdate - Return an analysis result or null if it doesn't exist
105 Pass *getAnalysisToUpdate(AnalysisID ID) const {
106 return getAnalysisOrNullUp(ID);
109 // Methods for introspecting into pass manager objects...
110 virtual unsigned getDepth() const = 0;
111 virtual unsigned getNumContainedPasses() const = 0;
112 virtual const Pass *getContainedPass(unsigned N) const = 0;
114 virtual void markPassUsed(AnalysisID P, Pass *User) = 0;
116 void startPass(Pass *P) {}
117 void endPass(Pass *P) {}
119 void setAnalysisResolver(Pass *P, AnalysisResolver *AR);
122 /// getAnalysisToUpdate<AnalysisType>() - This function is used by subclasses
123 /// to get to the analysis information that might be around that needs to be
124 /// updated. This is different than getAnalysis in that it can fail (ie the
125 /// analysis results haven't been computed), so should only be used if you
126 /// provide the capability to update an analysis that exists. This method is
127 /// often used by transformation APIs to update analysis results for a pass
128 /// automatically as the transform is performed.
130 template<typename AnalysisType>
131 AnalysisType *Pass::getAnalysisToUpdate() const {
132 assert(Resolver && "Pass not resident in a PassManager object!");
133 const PassInfo *PI = getClassPassInfo<AnalysisType>();
134 if (PI == 0) return 0;
135 return dynamic_cast<AnalysisType*>(Resolver->getAnalysisToUpdate(PI));
138 } // End llvm namespace