aboutsummaryrefslogtreecommitdiff
path: root/lib/Analysis/ValueManager.cpp
blob: fe670e79b3b534da49831a57aab65c31ed69d0f3 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
//== ValueManager.cpp - Aggregate manager of symbols and SVals --*- C++ -*--==//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
//  This file defines ValueManager, a class that manages symbolic values
//  and SVals created for use by GRExprEngine and related classes.  It
//  wraps and owns SymbolManager, MemRegionManager, and BasicValueFactory.
//
//===----------------------------------------------------------------------===//

#include "clang/Analysis/PathSensitive/ValueManager.h"

using namespace clang;
using namespace llvm;

//===----------------------------------------------------------------------===//
// Utility methods for constructing SVals.
//===----------------------------------------------------------------------===//

DefinedOrUnknownSVal ValueManager::makeZeroVal(QualType T) {
  if (Loc::IsLocType(T))
    return makeNull();

  if (T->isIntegerType())
    return makeIntVal(0, T);

  // FIXME: Handle floats.
  // FIXME: Handle structs.
  return UnknownVal();
}

//===----------------------------------------------------------------------===//
// Utility methods for constructing Non-Locs.
//===----------------------------------------------------------------------===//

NonLoc ValueManager::makeNonLoc(const SymExpr *lhs, BinaryOperator::Opcode op,
                                const APSInt& v, QualType T) {
  // The Environment ensures we always get a persistent APSInt in
  // BasicValueFactory, so we don't need to get the APSInt from
  // BasicValueFactory again.
  assert(!Loc::IsLocType(T));
  return nonloc::SymExprVal(SymMgr.getSymIntExpr(lhs, op, v, T));
}

NonLoc ValueManager::makeNonLoc(const SymExpr *lhs, BinaryOperator::Opcode op,
                                const SymExpr *rhs, QualType T) {
  assert(SymMgr.getType(lhs) == SymMgr.getType(rhs));
  assert(!Loc::IsLocType(T));
  return nonloc::SymExprVal(SymMgr.getSymSymExpr(lhs, op, rhs, T));
}


SVal ValueManager::convertToArrayIndex(SVal V) {
  if (V.isUnknownOrUndef())
    return V;

  // Common case: we have an appropriately sized integer.
  if (nonloc::ConcreteInt* CI = dyn_cast<nonloc::ConcreteInt>(&V)) {
    const llvm::APSInt& I = CI->getValue();
    if (I.getBitWidth() == ArrayIndexWidth && I.isSigned())
      return V;
  }

  return SVator->EvalCastNL(cast<NonLoc>(V), ArrayIndexTy);
}

DefinedOrUnknownSVal ValueManager::getRegionValueSymbolVal(const MemRegion* R,
                                                           QualType T) {

  if (T.isNull()) {
    const TypedRegion* TR = cast<TypedRegion>(R);
    T = TR->getValueType(SymMgr.getContext());
  }

  if (!SymbolManager::canSymbolicate(T))
    return UnknownVal();

  SymbolRef sym = SymMgr.getRegionValueSymbol(R, T);

  if (Loc::IsLocType(T))
    return loc::MemRegionVal(MemMgr.getSymbolicRegion(sym));

  return nonloc::SymbolVal(sym);
}

DefinedOrUnknownSVal ValueManager::getConjuredSymbolVal(const void *SymbolTag,
                                                        const Expr *E,
                                                        unsigned Count) {
  QualType T = E->getType();

  if (!SymbolManager::canSymbolicate(T))
    return UnknownVal();

  SymbolRef sym = SymMgr.getConjuredSymbol(E, Count, SymbolTag);

  if (Loc::IsLocType(T))
    return loc::MemRegionVal(MemMgr.getSymbolicRegion(sym));

  return nonloc::SymbolVal(sym);
}

DefinedOrUnknownSVal ValueManager::getConjuredSymbolVal(const void *SymbolTag,
                                                        const Expr *E,
                                                        QualType T,
                                                        unsigned Count) {
  
  if (!SymbolManager::canSymbolicate(T))
    return UnknownVal();

  SymbolRef sym = SymMgr.getConjuredSymbol(E, T, Count, SymbolTag);

  if (Loc::IsLocType(T))
    return loc::MemRegionVal(MemMgr.getSymbolicRegion(sym));

  return nonloc::SymbolVal(sym);
}


DefinedOrUnknownSVal
ValueManager::getDerivedRegionValueSymbolVal(SymbolRef parentSymbol,
                                             const TypedRegion *R) {
  QualType T = R->getValueType(R->getContext());

  if (!SymbolManager::canSymbolicate(T))
    return UnknownVal();

  SymbolRef sym = SymMgr.getDerivedSymbol(parentSymbol, R);

  if (Loc::IsLocType(T))
    return loc::MemRegionVal(MemMgr.getSymbolicRegion(sym));

  return nonloc::SymbolVal(sym);
}

DefinedSVal ValueManager::getFunctionPointer(const FunctionDecl* FD) {
  CodeTextRegion *R  = MemMgr.getCodeTextRegion(FD);
  return loc::MemRegionVal(R);
}