1 //===- SymExpr.h - Management of Symbolic Values ----------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines SymExpr and SymbolData.
12 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_SYMEXPR_H
15 #define LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_SYMEXPR_H
17 #include "clang/AST/Type.h"
18 #include "clang/Basic/LLVM.h"
19 #include "llvm/ADT/FoldingSet.h"
20 #include "llvm/ADT/SmallVector.h"
28 /// Symbolic value. These values used to capture symbolic execution of
30 class SymExpr : public llvm::FoldingSetNode {
31 virtual void anchor();
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"
44 SymExpr(Kind k) : K(k) {}
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();
52 mutable unsigned Complexity = 0;
55 virtual ~SymExpr() = default;
57 Kind getKind() const { return K; }
59 virtual void dump() const;
61 virtual void dumpToStream(raw_ostream &os) const {}
63 virtual QualType getType() const = 0;
64 virtual void Profile(llvm::FoldingSetNodeID &profile) = 0;
66 /// Iterator over symbols that the current symbol depends on.
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.
71 class symbol_iterator {
72 SmallVector<const SymExpr *, 5> itr;
77 symbol_iterator() = default;
78 symbol_iterator(const SymExpr *SE);
80 symbol_iterator &operator++();
81 const SymExpr *operator*();
83 bool operator==(const symbol_iterator &X) const;
84 bool operator!=(const symbol_iterator &X) const;
87 symbol_iterator symbol_begin() const { return symbol_iterator(this); }
88 static symbol_iterator symbol_end() { return symbol_iterator(); }
90 virtual unsigned computeComplexity() const = 0;
92 /// Find the region from which this symbol originates.
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; }
105 inline raw_ostream &operator<<(raw_ostream &os,
106 const clang::ento::SymExpr *SE) {
107 SE->dumpToStream(os);
111 using SymbolRef = const SymExpr *;
112 using SymbolRefSmallVectorTy = SmallVector<SymbolRef, 2>;
113 using SymbolID = unsigned;
115 /// A symbol representing data which can be stored in a memory location
117 class SymbolData : public SymExpr {
120 void anchor() override;
123 SymbolData(Kind k, SymbolID sym) : SymExpr(k), Sym(sym) {
124 assert(classof(this));
128 ~SymbolData() override = default;
130 SymbolID getSymbolID() const { return Sym; }
132 unsigned computeComplexity() const override {
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;
146 #endif // LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_SYMEXPR_H