1//== SimpleConstraintManager.cpp --------------------------------*- C++ -*--==//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file defines SimpleConstraintManager, a class that provides a
10// simplified constraint manager interface, compared to ConstraintManager.
11//
12//===----------------------------------------------------------------------===//
13
14#include "clang/StaticAnalyzer/Core/PathSensitive/SimpleConstraintManager.h"
15#include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h"
16#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"
17#include <optional>
18
19namespace clang {
20
21namespace ento {
22
23SimpleConstraintManager::~SimpleConstraintManager() {}
24
25ProgramStateRef SimpleConstraintManager::assumeInternal(ProgramStateRef State,
26 DefinedSVal Cond,
27 bool Assumption) {
28 // If we have a Loc value, cast it to a bool NonLoc first.
29 if (std::optional<Loc> LV = Cond.getAs<Loc>()) {
30 SValBuilder &SVB = State->getStateManager().getSValBuilder();
31 QualType T;
32 const MemRegion *MR = LV->getAsRegion();
33 if (const TypedRegion *TR = dyn_cast_or_null<TypedRegion>(Val: MR))
34 T = TR->getLocationType();
35 else
36 T = SVB.getContext().VoidPtrTy;
37
38 Cond = SVB.evalCast(V: *LV, CastTy: SVB.getContext().BoolTy, OriginalTy: T).castAs<DefinedSVal>();
39 }
40
41 return assume(State, Cond: Cond.castAs<NonLoc>(), Assumption);
42}
43
44ProgramStateRef SimpleConstraintManager::assume(ProgramStateRef State,
45 NonLoc Cond, bool Assumption) {
46 State = assumeAux(State, Cond, Assumption);
47 if (EE)
48 return EE->processAssume(state: State, cond: Cond, assumption: Assumption);
49 return State;
50}
51
52ProgramStateRef SimpleConstraintManager::assumeAux(ProgramStateRef State,
53 NonLoc Cond,
54 bool Assumption) {
55
56 // We cannot reason about SymSymExprs, and can only reason about some
57 // SymIntExprs.
58 if (!canReasonAbout(X: Cond)) {
59 // Just add the constraint to the expression without trying to simplify.
60 SymbolRef Sym = Cond.getAsSymbol();
61 assert(Sym);
62 return assumeSymUnsupported(State, Sym, Assumption);
63 }
64
65 switch (Cond.getKind()) {
66 default:
67 llvm_unreachable("'Assume' not implemented for this NonLoc");
68
69 case nonloc::SymbolValKind: {
70 nonloc::SymbolVal SV = Cond.castAs<nonloc::SymbolVal>();
71 SymbolRef Sym = SV.getSymbol();
72 assert(Sym);
73 return assumeSym(State, Sym, Assumption);
74 }
75
76 case nonloc::ConcreteIntKind: {
77 bool b = *Cond.castAs<nonloc::ConcreteInt>().getValue() != 0;
78 bool isFeasible = b ? Assumption : !Assumption;
79 return isFeasible ? State : nullptr;
80 }
81
82 case nonloc::PointerToMemberKind: {
83 bool IsNull = !Cond.castAs<nonloc::PointerToMember>().isNullMemberPointer();
84 bool IsFeasible = IsNull ? Assumption : !Assumption;
85 return IsFeasible ? State : nullptr;
86 }
87
88 case nonloc::LocAsIntegerKind:
89 return assumeInternal(State, Cond: Cond.castAs<nonloc::LocAsInteger>().getLoc(),
90 Assumption);
91 } // end switch
92}
93
94ProgramStateRef SimpleConstraintManager::assumeInclusiveRangeInternal(
95 ProgramStateRef State, NonLoc Value, const llvm::APSInt &From,
96 const llvm::APSInt &To, bool InRange) {
97
98 assert(From.isUnsigned() == To.isUnsigned() &&
99 From.getBitWidth() == To.getBitWidth() &&
100 "Values should have same types!");
101
102 if (!canReasonAbout(X: Value)) {
103 // Just add the constraint to the expression without trying to simplify.
104 SymbolRef Sym = Value.getAsSymbol();
105 assert(Sym);
106 return assumeSymInclusiveRange(State, Sym, From, To, InRange);
107 }
108
109 switch (Value.getKind()) {
110 default:
111 llvm_unreachable("'assumeInclusiveRange' is not implemented"
112 "for this NonLoc");
113
114 case nonloc::LocAsIntegerKind:
115 case nonloc::SymbolValKind: {
116 if (SymbolRef Sym = Value.getAsSymbol())
117 return assumeSymInclusiveRange(State, Sym, From, To, InRange);
118 return State;
119 } // end switch
120
121 case nonloc::ConcreteIntKind: {
122 const llvm::APSInt &IntVal = Value.castAs<nonloc::ConcreteInt>().getValue();
123 bool IsInRange = IntVal >= From && IntVal <= To;
124 bool isFeasible = (IsInRange == InRange);
125 return isFeasible ? State : nullptr;
126 }
127 } // end switch
128}
129
130} // end of namespace ento
131
132} // end of namespace clang
133