PassAnalysisSupport.h revision cb2610ea037a17115ef3a01a6bdaab4e3cfdca27 
1//===- llvm/PassAnalysisSupport.h - Analysis Pass Support code ---*- C++ -*-==//
2//
3// This file defines stuff that is used to define and "use" Analysis Passes.
4// This file is automatically #included by Pass.h, so:
5//
6//           NO .CPP FILES SHOULD INCLUDE THIS FILE DIRECTLY
7//
8// Instead, #include Pass.h
9//
10//===----------------------------------------------------------------------===//
11
12#ifndef LLVM_PASS_ANALYSIS_SUPPORT_H
13#define LLVM_PASS_ANALYSIS_SUPPORT_H
14
15// No need to include Pass.h, we are being included by it!
16
17
18
19//===----------------------------------------------------------------------===//
20// AnalysisUsage - Represent the analysis usage information of a pass.  This
21// tracks analyses that the pass REQUIRES (must available when the pass runs),
22// and analyses that the pass PRESERVES (the pass does not invalidate the
23// results of these analyses).  This information is provided by a pass to the
24// Pass infrastructure through the getAnalysisUsage virtual function.
25//
26class AnalysisUsage {
27  // Sets of analyses required and preserved by a pass
28  std::vector<AnalysisID> Required, Preserved;
29  bool PreservesAll;
30public:
31  AnalysisUsage() : PreservesAll(false) {}
32
33  // addRequired - Add the specified ID to the required set of the usage info
34  // for a pass.
35  //
36  AnalysisUsage &addRequiredID(AnalysisID ID) {
37    Required.push_back(ID);
38    return *this;
39  }
40  template<class PassClass>
41  AnalysisUsage &addRequired() {
42    assert(Pass::getClassPassInfo<PassClass>() && "Pass class not registered!");
43    Required.push_back(Pass::getClassPassInfo<PassClass>());
44    return *this;
45  }
46
47  // addPreserved - Add the specified ID to the set of analyses preserved by
48  // this pass
49  //
50  AnalysisUsage &addPreservedID(AnalysisID ID) {
51    Preserved.push_back(ID);
52    return *this;
53  }
54
55  template<class PassClass>
56  AnalysisUsage &addPreserved() {
57    assert(Pass::getClassPassInfo<PassClass>() && "Pass class not registered!");
58    Preserved.push_back(Pass::getClassPassInfo<PassClass>());
59    return *this;
60  }
61
62  // setPreservesAll - Set by analyses that do not transform their input at all
63  void setPreservesAll() { PreservesAll = true; }
64  bool getPreservesAll() const { return PreservesAll; }
65
66  /// setPreservesCFG - This function should be called by the pass, iff they do
67  /// not:
68  ///
69  ///  1. Add or remove basic blocks from the function
70  ///  2. Modify terminator instructions in any way.
71  ///
72  /// This function annotates the AnalysisUsage info object to say that analyses
73  /// that only depend on the CFG are preserved by this pass.
74  ///
75  void setPreservesCFG();
76
77  const std::vector<AnalysisID> &getRequiredSet() const { return Required; }
78  const std::vector<AnalysisID> &getPreservedSet() const { return Preserved; }
79};
80
81
82
83//===----------------------------------------------------------------------===//
84// AnalysisResolver - Simple interface implemented by PassManager objects that
85// is used to pull analysis information out of them.
86//
87struct AnalysisResolver {
88  virtual Pass *getAnalysisOrNullUp(AnalysisID ID) const = 0;
89  virtual Pass *getAnalysisOrNullDown(AnalysisID ID) const = 0;
90  virtual void addPass(ImmutablePass *IP, AnalysisUsage &AU) = 0;
91  Pass *getAnalysis(AnalysisID ID) const {
92    Pass *Result = getAnalysisOrNullUp(ID);
93    assert(Result && "Pass has an incorrect analysis uses set!");
94    return Result;
95  }
96
97  // getAnalysisToUpdate - Return an analysis result or null if it doesn't exist
98  Pass *getAnalysisToUpdate(AnalysisID ID) const {
99    return getAnalysisOrNullUp(ID);
100  }
101
102  // Methods for introspecting into pass manager objects...
103  virtual unsigned getDepth() const = 0;
104  virtual unsigned getNumContainedPasses() const = 0;
105  virtual const Pass *getContainedPass(unsigned N) const = 0;
106
107  virtual void markPassUsed(AnalysisID P, Pass *User) = 0;
108
109  void startPass(Pass *P) {}
110  void endPass(Pass *P) {}
111protected:
112  void setAnalysisResolver(Pass *P, AnalysisResolver *AR);
113};
114
115#endif
116