llvm-project/clang/lib/StaticAnalyzer/Core/SimpleConstraintManager.cpp

133 lines
4.6 KiB
C++

//== SimpleConstraintManager.cpp --------------------------------*- C++ -*--==//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file defines SimpleConstraintManager, a class that provides a
// simplified constraint manager interface, compared to ConstraintManager.
//
//===----------------------------------------------------------------------===//
#include "clang/StaticAnalyzer/Core/PathSensitive/SimpleConstraintManager.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/APSIntType.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"
namespace clang {
namespace ento {
SimpleConstraintManager::~SimpleConstraintManager() {}
ProgramStateRef SimpleConstraintManager::assume(ProgramStateRef State,
DefinedSVal Cond,
bool Assumption) {
// If we have a Loc value, cast it to a bool NonLoc first.
if (Optional<Loc> LV = Cond.getAs<Loc>()) {
SValBuilder &SVB = State->getStateManager().getSValBuilder();
QualType T;
const MemRegion *MR = LV->getAsRegion();
if (const TypedRegion *TR = dyn_cast_or_null<TypedRegion>(MR))
T = TR->getLocationType();
else
T = SVB.getContext().VoidPtrTy;
Cond = SVB.evalCast(*LV, SVB.getContext().BoolTy, T).castAs<DefinedSVal>();
}
return assume(State, Cond.castAs<NonLoc>(), Assumption);
}
ProgramStateRef SimpleConstraintManager::assume(ProgramStateRef State,
NonLoc Cond, bool Assumption) {
State = assumeAux(State, Cond, Assumption);
if (NotifyAssumeClients && SU)
return SU->processAssume(State, Cond, Assumption);
return State;
}
ProgramStateRef SimpleConstraintManager::assumeAux(ProgramStateRef State,
NonLoc Cond,
bool Assumption) {
// We cannot reason about SymSymExprs, and can only reason about some
// SymIntExprs.
if (!canReasonAbout(Cond)) {
// Just add the constraint to the expression without trying to simplify.
SymbolRef Sym = Cond.getAsSymExpr();
assert(Sym);
return assumeSymUnsupported(State, Sym, Assumption);
}
switch (Cond.getSubKind()) {
default:
llvm_unreachable("'Assume' not implemented for this NonLoc");
case nonloc::SymbolValKind: {
nonloc::SymbolVal SV = Cond.castAs<nonloc::SymbolVal>();
SymbolRef Sym = SV.getSymbol();
assert(Sym);
return assumeSym(State, Sym, Assumption);
}
case nonloc::ConcreteIntKind: {
bool b = Cond.castAs<nonloc::ConcreteInt>().getValue() != 0;
bool isFeasible = b ? Assumption : !Assumption;
return isFeasible ? State : nullptr;
}
case nonloc::PointerToMemberKind: {
bool IsNull = !Cond.castAs<nonloc::PointerToMember>().isNullMemberPointer();
bool IsFeasible = IsNull ? Assumption : !Assumption;
return IsFeasible ? State : nullptr;
}
case nonloc::LocAsIntegerKind:
return assume(State, Cond.castAs<nonloc::LocAsInteger>().getLoc(),
Assumption);
} // end switch
}
ProgramStateRef SimpleConstraintManager::assumeInclusiveRange(
ProgramStateRef State, NonLoc Value, const llvm::APSInt &From,
const llvm::APSInt &To, bool InRange) {
assert(From.isUnsigned() == To.isUnsigned() &&
From.getBitWidth() == To.getBitWidth() &&
"Values should have same types!");
if (!canReasonAbout(Value)) {
// Just add the constraint to the expression without trying to simplify.
SymbolRef Sym = Value.getAsSymExpr();
assert(Sym);
return assumeSymInclusiveRange(State, Sym, From, To, InRange);
}
switch (Value.getSubKind()) {
default:
llvm_unreachable("'assumeInclusiveRange' is not implemented"
"for this NonLoc");
case nonloc::LocAsIntegerKind:
case nonloc::SymbolValKind: {
if (SymbolRef Sym = Value.getAsSymbol())
return assumeSymInclusiveRange(State, Sym, From, To, InRange);
return State;
} // end switch
case nonloc::ConcreteIntKind: {
const llvm::APSInt &IntVal = Value.castAs<nonloc::ConcreteInt>().getValue();
bool IsInRange = IntVal >= From && IntVal <= To;
bool isFeasible = (IsInRange == InRange);
return isFeasible ? State : nullptr;
}
} // end switch
}
} // end of namespace ento
} // end of namespace clang