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// SValBuilder.h - Construction of SVals from evaluating expressions -*- 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 SValBuilder, a class that defines the interface for
// "symbolical evaluators" which construct an SVal from an expression.
#include "clang/AST/ASTContext.h"
#include "clang/AST/Expr.h"
#include "clang/AST/ExprObjC.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/BasicValueFactory.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/SVals.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/SymbolManager.h"
namespace clang {
class CXXBoolLiteralExpr;
namespace ento {
class SValBuilder {
virtual void anchor();
ASTContext &Context;
/// Manager of APSInt values.
BasicValueFactory BasicVals;
/// Manages the creation of symbols.
SymbolManager SymMgr;
/// Manages the creation of memory regions.
MemRegionManager MemMgr;
ProgramStateManager &StateMgr;
/// The scalar type to use for array indices.
const QualType ArrayIndexTy;
/// The width of the scalar type used for array indices.
const unsigned ArrayIndexWidth;
virtual SVal evalCastFromNonLoc(NonLoc val, QualType castTy) = 0;
virtual SVal evalCastFromLoc(Loc val, QualType castTy) = 0;
// FIXME: Make these protected again once RegionStoreManager correctly
// handles loads from different bound value types.
virtual SVal dispatchCast(SVal val, QualType castTy) = 0;
SValBuilder(llvm::BumpPtrAllocator &alloc, ASTContext &context,
ProgramStateManager &stateMgr)
: Context(context), BasicVals(context, alloc),
SymMgr(context, BasicVals, alloc),
MemMgr(context, alloc),
ArrayIndexWidth(context.getTypeSize(ArrayIndexTy)) {}
virtual ~SValBuilder() {}
bool haveSameType(const SymExpr *Sym1, const SymExpr *Sym2) {
return haveSameType(Sym1->getType(), Sym2->getType());
bool haveSameType(QualType Ty1, QualType Ty2) {
// FIXME: Remove the second disjunct when we support symbolic
// truncation/extension.
return (Context.getCanonicalType(Ty1) == Context.getCanonicalType(Ty2) ||
(Ty1->isIntegralOrEnumerationType() &&
SVal evalCast(SVal val, QualType castTy, QualType originalType);
// Handles casts of type CK_IntegralCast.
SVal evalIntegralCast(ProgramStateRef state, SVal val, QualType castTy,
QualType originalType);
virtual SVal evalMinus(NonLoc val) = 0;
virtual SVal evalComplement(NonLoc val) = 0;
/// Create a new value which represents a binary expression with two non-
/// location operands.
virtual SVal evalBinOpNN(ProgramStateRef state, BinaryOperator::Opcode op,
NonLoc lhs, NonLoc rhs, QualType resultTy) = 0;
/// Create a new value which represents a binary expression with two memory
/// location operands.
virtual SVal evalBinOpLL(ProgramStateRef state, BinaryOperator::Opcode op,
Loc lhs, Loc rhs, QualType resultTy) = 0;
/// Create a new value which represents a binary expression with a memory
/// location and non-location operands. For example, this would be used to
/// evaluate a pointer arithmetic operation.
virtual SVal evalBinOpLN(ProgramStateRef state, BinaryOperator::Opcode op,
Loc lhs, NonLoc rhs, QualType resultTy) = 0;
/// Evaluates a given SVal. If the SVal has only one possible (integer) value,
/// that value is returned. Otherwise, returns NULL.
virtual const llvm::APSInt *getKnownValue(ProgramStateRef state, SVal val) = 0;
/// Simplify symbolic expressions within a given SVal. Return an SVal
/// that represents the same value, but is hopefully easier to work with
/// than the original SVal.
virtual SVal simplifySVal(ProgramStateRef State, SVal Val) = 0;
/// Constructs a symbolic expression for two non-location values.
SVal makeSymExprValNN(ProgramStateRef state, BinaryOperator::Opcode op,
NonLoc lhs, NonLoc rhs, QualType resultTy);
SVal evalBinOp(ProgramStateRef state, BinaryOperator::Opcode op,
SVal lhs, SVal rhs, QualType type);
DefinedOrUnknownSVal evalEQ(ProgramStateRef state, DefinedOrUnknownSVal lhs,
DefinedOrUnknownSVal rhs);
ASTContext &getContext() { return Context; }
const ASTContext &getContext() const { return Context; }
ProgramStateManager &getStateManager() { return StateMgr; }
QualType getConditionType() const {
return Context.getLangOpts().CPlusPlus ? Context.BoolTy : Context.IntTy;
QualType getArrayIndexType() const {
return ArrayIndexTy;
BasicValueFactory &getBasicValueFactory() { return BasicVals; }
const BasicValueFactory &getBasicValueFactory() const { return BasicVals; }
SymbolManager &getSymbolManager() { return SymMgr; }
const SymbolManager &getSymbolManager() const { return SymMgr; }
MemRegionManager &getRegionManager() { return MemMgr; }
const MemRegionManager &getRegionManager() const { return MemMgr; }
// Forwarding methods to SymbolManager.
const SymbolConjured* conjureSymbol(const Stmt *stmt,
const LocationContext *LCtx,
QualType type,
unsigned visitCount,
const void *symbolTag = nullptr) {
return SymMgr.conjureSymbol(stmt, LCtx, type, visitCount, symbolTag);
const SymbolConjured* conjureSymbol(const Expr *expr,
const LocationContext *LCtx,
unsigned visitCount,
const void *symbolTag = nullptr) {
return SymMgr.conjureSymbol(expr, LCtx, visitCount, symbolTag);
/// Construct an SVal representing '0' for the specified type.
DefinedOrUnknownSVal makeZeroVal(QualType type);
/// Make a unique symbol for value of region.
DefinedOrUnknownSVal getRegionValueSymbolVal(const TypedValueRegion *region);
/// \brief Create a new symbol with a unique 'name'.
/// We resort to conjured symbols when we cannot construct a derived symbol.
/// The advantage of symbols derived/built from other symbols is that we
/// preserve the relation between related(or even equivalent) expressions, so
/// conjured symbols should be used sparingly.
DefinedOrUnknownSVal conjureSymbolVal(const void *symbolTag,
const Expr *expr,
const LocationContext *LCtx,
unsigned count);
DefinedOrUnknownSVal conjureSymbolVal(const void *symbolTag,
const Expr *expr,
const LocationContext *LCtx,
QualType type,
unsigned count);
DefinedOrUnknownSVal conjureSymbolVal(const Stmt *stmt,
const LocationContext *LCtx,
QualType type,
unsigned visitCount);
/// \brief Conjure a symbol representing heap allocated memory region.
/// Note, the expression should represent a location.
DefinedOrUnknownSVal getConjuredHeapSymbolVal(const Expr *E,
const LocationContext *LCtx,
unsigned Count);
DefinedOrUnknownSVal getDerivedRegionValueSymbolVal(
SymbolRef parentSymbol, const TypedValueRegion *region);
DefinedSVal getMetadataSymbolVal(const void *symbolTag,
const MemRegion *region,
const Expr *expr, QualType type,
const LocationContext *LCtx,
unsigned count);
DefinedSVal getMemberPointer(const DeclaratorDecl *DD);
DefinedSVal getFunctionPointer(const FunctionDecl *func);
DefinedSVal getBlockPointer(const BlockDecl *block, CanQualType locTy,
const LocationContext *locContext,
unsigned blockCount);
/// Returns the value of \p E, if it can be determined in a non-path-sensitive
/// manner.
/// If \p E is not a constant or cannot be modeled, returns \c None.
Optional<SVal> getConstantVal(const Expr *E);
NonLoc makeCompoundVal(QualType type, llvm::ImmutableList<SVal> vals) {
return nonloc::CompoundVal(BasicVals.getCompoundValData(type, vals));
NonLoc makeLazyCompoundVal(const StoreRef &store,
const TypedValueRegion *region) {
return nonloc::LazyCompoundVal(
BasicVals.getLazyCompoundValData(store, region));
NonLoc makePointerToMember(const DeclaratorDecl *DD) {
return nonloc::PointerToMember(DD);
NonLoc makePointerToMember(const PointerToMemberData *PTMD) {
return nonloc::PointerToMember(PTMD);
NonLoc makeZeroArrayIndex() {
return nonloc::ConcreteInt(BasicVals.getValue(0, ArrayIndexTy));
NonLoc makeArrayIndex(uint64_t idx) {
return nonloc::ConcreteInt(BasicVals.getValue(idx, ArrayIndexTy));
SVal convertToArrayIndex(SVal val);
nonloc::ConcreteInt makeIntVal(const IntegerLiteral* integer) {
return nonloc::ConcreteInt(
nonloc::ConcreteInt makeBoolVal(const ObjCBoolLiteralExpr *boolean) {
return makeTruthVal(boolean->getValue(), boolean->getType());
nonloc::ConcreteInt makeBoolVal(const CXXBoolLiteralExpr *boolean);
nonloc::ConcreteInt makeIntVal(const llvm::APSInt& integer) {
return nonloc::ConcreteInt(BasicVals.getValue(integer));
loc::ConcreteInt makeIntLocVal(const llvm::APSInt &integer) {
return loc::ConcreteInt(BasicVals.getValue(integer));
NonLoc makeIntVal(const llvm::APInt& integer, bool isUnsigned) {
return nonloc::ConcreteInt(BasicVals.getValue(integer, isUnsigned));
DefinedSVal makeIntVal(uint64_t integer, QualType type) {
if (Loc::isLocType(type))
return loc::ConcreteInt(BasicVals.getValue(integer, type));
return nonloc::ConcreteInt(BasicVals.getValue(integer, type));
NonLoc makeIntVal(uint64_t integer, bool isUnsigned) {
return nonloc::ConcreteInt(BasicVals.getIntValue(integer, isUnsigned));
NonLoc makeIntValWithPtrWidth(uint64_t integer, bool isUnsigned) {
return nonloc::ConcreteInt(
BasicVals.getIntWithPtrWidth(integer, isUnsigned));
NonLoc makeLocAsInteger(Loc loc, unsigned bits) {
return nonloc::LocAsInteger(BasicVals.getPersistentSValWithData(loc, bits));
NonLoc makeNonLoc(const SymExpr *lhs, BinaryOperator::Opcode op,
const llvm::APSInt& rhs, QualType type);
NonLoc makeNonLoc(const llvm::APSInt& rhs, BinaryOperator::Opcode op,
const SymExpr *lhs, QualType type);
NonLoc makeNonLoc(const SymExpr *lhs, BinaryOperator::Opcode op,
const SymExpr *rhs, QualType type);
/// \brief Create a NonLoc value for cast.
NonLoc makeNonLoc(const SymExpr *operand, QualType fromTy, QualType toTy);
nonloc::ConcreteInt makeTruthVal(bool b, QualType type) {
return nonloc::ConcreteInt(BasicVals.getTruthValue(b, type));
nonloc::ConcreteInt makeTruthVal(bool b) {
return nonloc::ConcreteInt(BasicVals.getTruthValue(b));
Loc makeNull() {
return loc::ConcreteInt(BasicVals.getZeroWithPtrWidth());
Loc makeLoc(SymbolRef sym) {
return loc::MemRegionVal(MemMgr.getSymbolicRegion(sym));
Loc makeLoc(const MemRegion* region) {
return loc::MemRegionVal(region);
Loc makeLoc(const AddrLabelExpr *expr) {
return loc::GotoLabel(expr->getLabel());
Loc makeLoc(const llvm::APSInt& integer) {
return loc::ConcreteInt(BasicVals.getValue(integer));
/// Return a memory region for the 'this' object reference.
loc::MemRegionVal getCXXThis(const CXXMethodDecl *D,
const StackFrameContext *SFC);
/// Return a memory region for the 'this' object reference.
loc::MemRegionVal getCXXThis(const CXXRecordDecl *D,
const StackFrameContext *SFC);
SValBuilder* createSimpleSValBuilder(llvm::BumpPtrAllocator &alloc,
ASTContext &context,
ProgramStateManager &stateMgr);
} // end GR namespace
} // end clang namespace