clang  8.0.0svn
SymExpr.h
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1 //===- SymExpr.h - Management of Symbolic Values ----------------*- C++ -*-===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file defines SymExpr and SymbolData.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_SYMEXPR_H
15 #define LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_SYMEXPR_H
16 
17 #include "clang/AST/Type.h"
18 #include "clang/Basic/LLVM.h"
19 #include "llvm/ADT/FoldingSet.h"
20 #include "llvm/ADT/SmallVector.h"
21 #include <cassert>
22 
23 namespace clang {
24 namespace ento {
25 
26 class MemRegion;
27 
28 /// Symbolic value. These values used to capture symbolic execution of
29 /// the program.
30 class SymExpr : public llvm::FoldingSetNode {
31  virtual void anchor();
32 
33 public:
34  enum Kind {
35 #define SYMBOL(Id, Parent) Id##Kind,
36 #define SYMBOL_RANGE(Id, First, Last) BEGIN_##Id = First, END_##Id = Last,
37 #include "clang/StaticAnalyzer/Core/PathSensitive/Symbols.def"
38  };
39 
40 private:
41  Kind K;
42 
43 protected:
44  SymExpr(Kind k) : K(k) {}
45 
46  static bool isValidTypeForSymbol(QualType T) {
47  // FIXME: Depending on whether we choose to deprecate structural symbols,
48  // this may become much stricter.
49  return !T.isNull() && !T->isVoidType();
50  }
51 
52  mutable unsigned Complexity = 0;
53 
54 public:
55  virtual ~SymExpr() = default;
56 
57  Kind getKind() const { return K; }
58 
59  virtual void dump() const;
60 
61  virtual void dumpToStream(raw_ostream &os) const {}
62 
63  virtual QualType getType() const = 0;
64  virtual void Profile(llvm::FoldingSetNodeID &profile) = 0;
65 
66  /// Iterator over symbols that the current symbol depends on.
67  ///
68  /// For SymbolData, it's the symbol itself; for expressions, it's the
69  /// expression symbol and all the operands in it. Note, SymbolDerived is
70  /// treated as SymbolData - the iterator will NOT visit the parent region.
73 
74  void expand();
75 
76  public:
77  symbol_iterator() = default;
78  symbol_iterator(const SymExpr *SE);
79 
81  const SymExpr *operator*();
82 
83  bool operator==(const symbol_iterator &X) const;
84  bool operator!=(const symbol_iterator &X) const;
85  };
86 
87  symbol_iterator symbol_begin() const { return symbol_iterator(this); }
89 
90  virtual unsigned computeComplexity() const = 0;
91 
92  /// Find the region from which this symbol originates.
93  ///
94  /// Whenever the symbol was constructed to denote an unknown value of
95  /// a certain memory region, return this region. This method
96  /// allows checkers to make decisions depending on the origin of the symbol.
97  /// Symbol classes for which the origin region is known include
98  /// SymbolRegionValue which denotes the value of the region before
99  /// the beginning of the analysis, and SymbolDerived which denotes the value
100  /// of a certain memory region after its super region (a memory space or
101  /// a larger record region) is default-bound with a certain symbol.
102  virtual const MemRegion *getOriginRegion() const { return nullptr; }
103 };
104 
105 inline raw_ostream &operator<<(raw_ostream &os,
106  const clang::ento::SymExpr *SE) {
107  SE->dumpToStream(os);
108  return os;
109 }
110 
111 using SymbolRef = const SymExpr *;
113 using SymbolID = unsigned;
114 
115 /// A symbol representing data which can be stored in a memory location
116 /// (region).
117 class SymbolData : public SymExpr {
118  const SymbolID Sym;
119 
120  void anchor() override;
121 
122 protected:
123  SymbolData(Kind k, SymbolID sym) : SymExpr(k), Sym(sym) {
124  assert(classof(this));
125  }
126 
127 public:
128  ~SymbolData() override = default;
129 
130  SymbolID getSymbolID() const { return Sym; }
131 
132  unsigned computeComplexity() const override {
133  return 1;
134  };
135 
136  // Implement isa<T> support.
137  static inline bool classof(const SymExpr *SE) {
138  Kind k = SE->getKind();
139  return k >= BEGIN_SYMBOLS && k <= END_SYMBOLS;
140  }
141 };
142 
143 } // namespace ento
144 } // namespace clang
145 
146 #endif // LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_SYMEXPR_H
A (possibly-)qualified type.
Definition: Type.h:642
MemRegion - The root abstract class for all memory regions.
Definition: MemRegion.h:94
C Language Family Type Representation.
bool operator!=(const symbol_iterator &X) const
virtual unsigned computeComplexity() const =0
virtual void dump() const
virtual const MemRegion * getOriginRegion() const
Find the region from which this symbol originates.
Definition: SymExpr.h:102
Symbolic value.
Definition: SymExpr.h:30
symbol_iterator symbol_begin() const
Definition: SymExpr.h:87
unsigned Complexity
Definition: SymExpr.h:52
virtual void dumpToStream(raw_ostream &os) const
Definition: SymExpr.h:61
Forward-declares and imports various common LLVM datatypes that clang wants to use unqualified...
virtual QualType getType() const =0
virtual ~SymExpr()=default
SymbolID getSymbolID() const
Definition: SymExpr.h:130
static bool classof(const SymExpr *SE)
Definition: SymExpr.h:137
bool isNull() const
Return true if this QualType doesn&#39;t point to a type yet.
Definition: Type.h:707
Kind
unsigned computeComplexity() const override
Definition: SymExpr.h:132
virtual void Profile(llvm::FoldingSetNodeID &profile)=0
static bool isValidTypeForSymbol(QualType T)
Definition: SymExpr.h:46
Dataflow Directional Tag Classes.
raw_ostream & operator<<(raw_ostream &Out, const CheckerBase &Checker)
Dump checker name to stream.
Definition: Checker.cpp:36
static symbol_iterator symbol_end()
Definition: SymExpr.h:88
SymbolData(Kind k, SymbolID sym)
Definition: SymExpr.h:123
static bool classof(const OMPClause *T)
Kind getKind() const
Definition: SymExpr.h:57
X
Add a minimal nested name specifier fixit hint to allow lookup of a tag name from an outer enclosing ...
Definition: SemaDecl.cpp:13803
unsigned SymbolID
Definition: SymExpr.h:113
bool isVoidType() const
Definition: Type.h:6497
bool operator==(const symbol_iterator &X) const
A symbol representing data which can be stored in a memory location (region).
Definition: SymExpr.h:117
Iterator over symbols that the current symbol depends on.
Definition: SymExpr.h:71