1 // SValBuilder.h - Construction of SVals from evaluating expressions -*- C++ -*- 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This file defines SValBuilder, a class that defines the interface for 11 // "symbolical evaluators" which construct an SVal from an expression. 12 // 13 //===----------------------------------------------------------------------===// 14 15 #ifndef LLVM_CLANG_GR_SVALBUILDER 16 #define LLVM_CLANG_GR_SVALBUILDER 17 18 #include "clang/AST/ASTContext.h" 19 #include "clang/AST/Expr.h" 20 #include "clang/AST/ExprObjC.h" 21 #include "clang/StaticAnalyzer/Core/PathSensitive/BasicValueFactory.h" 22 #include "clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h" 23 #include "clang/StaticAnalyzer/Core/PathSensitive/SVals.h" 24 25 namespace clang { 26 27 class CXXBoolLiteralExpr; 28 29 namespace ento { 30 31 class SValBuilder { 32 virtual void anchor(); 33 protected: 34 ASTContext &Context; 35 36 /// Manager of APSInt values. 37 BasicValueFactory BasicVals; 38 39 /// Manages the creation of symbols. 40 SymbolManager SymMgr; 41 42 /// Manages the creation of memory regions. 43 MemRegionManager MemMgr; 44 45 ProgramStateManager &StateMgr; 46 47 /// The scalar type to use for array indices. 48 const QualType ArrayIndexTy; 49 50 /// The width of the scalar type used for array indices. 51 const unsigned ArrayIndexWidth; 52 53 virtual SVal evalCastFromNonLoc(NonLoc val, QualType castTy) = 0; 54 virtual SVal evalCastFromLoc(Loc val, QualType castTy) = 0; 55 56 public: 57 // FIXME: Make these protected again once RegionStoreManager correctly 58 // handles loads from different bound value types. 59 virtual SVal dispatchCast(SVal val, QualType castTy) = 0; 60 61 public: 62 SValBuilder(llvm::BumpPtrAllocator &alloc, ASTContext &context, 63 ProgramStateManager &stateMgr) 64 : Context(context), BasicVals(context, alloc), 65 SymMgr(context, BasicVals, alloc), 66 MemMgr(context, alloc), 67 StateMgr(stateMgr), 68 ArrayIndexTy(context.IntTy), 69 ArrayIndexWidth(context.getTypeSize(ArrayIndexTy)) {} 70 71 virtual ~SValBuilder() {} 72 73 bool haveSameType(const SymExpr *Sym1, const SymExpr *Sym2) { 74 return haveSameType(Sym1->getType(), Sym2->getType()); 75 } 76 77 bool haveSameType(QualType Ty1, QualType Ty2) { 78 // FIXME: Remove the second disjunct when we support symbolic 79 // truncation/extension. 80 return (Context.getCanonicalType(Ty1) == Context.getCanonicalType(Ty2) || 81 (Ty1->isIntegralOrEnumerationType() && 82 Ty2->isIntegralOrEnumerationType())); 83 } 84 85 SVal evalCast(SVal val, QualType castTy, QualType originalType); 86 87 virtual SVal evalMinus(NonLoc val) = 0; 88 89 virtual SVal evalComplement(NonLoc val) = 0; 90 91 /// Create a new value which represents a binary expression with two non 92 /// location operands. 93 virtual SVal evalBinOpNN(ProgramStateRef state, BinaryOperator::Opcode op, 94 NonLoc lhs, NonLoc rhs, QualType resultTy) = 0; 95 96 /// Create a new value which represents a binary expression with two memory 97 /// location operands. 98 virtual SVal evalBinOpLL(ProgramStateRef state, BinaryOperator::Opcode op, 99 Loc lhs, Loc rhs, QualType resultTy) = 0; 100 101 /// Create a new value which represents a binary expression with a memory 102 /// location and non location operands. For example, this would be used to 103 /// evaluate a pointer arithmetic operation. 104 virtual SVal evalBinOpLN(ProgramStateRef state, BinaryOperator::Opcode op, 105 Loc lhs, NonLoc rhs, QualType resultTy) = 0; 106 107 /// Evaluates a given SVal. If the SVal has only one possible (integer) value, 108 /// that value is returned. Otherwise, returns NULL. 109 virtual const llvm::APSInt *getKnownValue(ProgramStateRef state, SVal val) = 0; 110 111 /// Constructs a symbolic expression for two non-location values. 112 SVal makeSymExprValNN(ProgramStateRef state, BinaryOperator::Opcode op, 113 NonLoc lhs, NonLoc rhs, QualType resultTy); 114 115 SVal evalBinOp(ProgramStateRef state, BinaryOperator::Opcode op, 116 SVal lhs, SVal rhs, QualType type); 117 118 DefinedOrUnknownSVal evalEQ(ProgramStateRef state, DefinedOrUnknownSVal lhs, 119 DefinedOrUnknownSVal rhs); 120 121 ASTContext &getContext() { return Context; } 122 const ASTContext &getContext() const { return Context; } 123 124 ProgramStateManager &getStateManager() { return StateMgr; } 125 126 QualType getConditionType() const { 127 return Context.getLangOpts().CPlusPlus ? Context.BoolTy : Context.IntTy; 128 } 129 130 QualType getArrayIndexType() const { 131 return ArrayIndexTy; 132 } 133 134 BasicValueFactory &getBasicValueFactory() { return BasicVals; } 135 const BasicValueFactory &getBasicValueFactory() const { return BasicVals; } 136 137 SymbolManager &getSymbolManager() { return SymMgr; } 138 const SymbolManager &getSymbolManager() const { return SymMgr; } 139 140 MemRegionManager &getRegionManager() { return MemMgr; } 141 const MemRegionManager &getRegionManager() const { return MemMgr; } 142 143 // Forwarding methods to SymbolManager. 144 145 const SymbolConjured* conjureSymbol(const Stmt *stmt, 146 const LocationContext *LCtx, 147 QualType type, 148 unsigned visitCount, 149 const void *symbolTag = 0) { 150 return SymMgr.conjureSymbol(stmt, LCtx, type, visitCount, symbolTag); 151 } 152 153 const SymbolConjured* conjureSymbol(const Expr *expr, 154 const LocationContext *LCtx, 155 unsigned visitCount, 156 const void *symbolTag = 0) { 157 return SymMgr.conjureSymbol(expr, LCtx, visitCount, symbolTag); 158 } 159 160 /// Construct an SVal representing '0' for the specified type. 161 DefinedOrUnknownSVal makeZeroVal(QualType type); 162 163 /// Make a unique symbol for value of region. 164 DefinedOrUnknownSVal getRegionValueSymbolVal(const TypedValueRegion *region); 165 166 /// \brief Create a new symbol with a unique 'name'. 167 /// 168 /// We resort to conjured symbols when we cannot construct a derived symbol. 169 /// The advantage of symbols derived/built from other symbols is that we 170 /// preserve the relation between related(or even equivalent) expressions, so 171 /// conjured symbols should be used sparingly. 172 DefinedOrUnknownSVal conjureSymbolVal(const void *symbolTag, 173 const Expr *expr, 174 const LocationContext *LCtx, 175 unsigned count); 176 DefinedOrUnknownSVal conjureSymbolVal(const void *symbolTag, 177 const Expr *expr, 178 const LocationContext *LCtx, 179 QualType type, 180 unsigned count); 181 182 DefinedOrUnknownSVal conjureSymbolVal(const Stmt *stmt, 183 const LocationContext *LCtx, 184 QualType type, 185 unsigned visitCount); 186 /// \brief Conjure a symbol representing heap allocated memory region. 187 /// 188 /// Note, the expression should represent a location. 189 DefinedOrUnknownSVal getConjuredHeapSymbolVal(const Expr *E, 190 const LocationContext *LCtx, 191 unsigned Count); 192 193 DefinedOrUnknownSVal getDerivedRegionValueSymbolVal( 194 SymbolRef parentSymbol, const TypedValueRegion *region); 195 196 DefinedSVal getMetadataSymbolVal( 197 const void *symbolTag, const MemRegion *region, 198 const Expr *expr, QualType type, unsigned count); 199 200 DefinedSVal getFunctionPointer(const FunctionDecl *func); 201 202 DefinedSVal getBlockPointer(const BlockDecl *block, CanQualType locTy, 203 const LocationContext *locContext); 204 205 /// Returns the value of \p E, if it can be determined in a non-path-sensitive 206 /// manner. 207 /// 208 /// If \p E is not a constant or cannot be modeled, returns \c None. 209 Optional<SVal> getConstantVal(const Expr *E); 210 211 NonLoc makeCompoundVal(QualType type, llvm::ImmutableList<SVal> vals) { 212 return nonloc::CompoundVal(BasicVals.getCompoundValData(type, vals)); 213 } 214 215 NonLoc makeLazyCompoundVal(const StoreRef &store, 216 const TypedValueRegion *region) { 217 return nonloc::LazyCompoundVal( 218 BasicVals.getLazyCompoundValData(store, region)); 219 } 220 221 NonLoc makeZeroArrayIndex() { 222 return nonloc::ConcreteInt(BasicVals.getValue(0, ArrayIndexTy)); 223 } 224 225 NonLoc makeArrayIndex(uint64_t idx) { 226 return nonloc::ConcreteInt(BasicVals.getValue(idx, ArrayIndexTy)); 227 } 228 229 SVal convertToArrayIndex(SVal val); 230 231 nonloc::ConcreteInt makeIntVal(const IntegerLiteral* integer) { 232 return nonloc::ConcreteInt( 233 BasicVals.getValue(integer->getValue(), 234 integer->getType()->isUnsignedIntegerOrEnumerationType())); 235 } 236 237 nonloc::ConcreteInt makeBoolVal(const ObjCBoolLiteralExpr *boolean) { 238 return makeTruthVal(boolean->getValue(), boolean->getType()); 239 } 240 241 nonloc::ConcreteInt makeBoolVal(const CXXBoolLiteralExpr *boolean); 242 243 nonloc::ConcreteInt makeIntVal(const llvm::APSInt& integer) { 244 return nonloc::ConcreteInt(BasicVals.getValue(integer)); 245 } 246 247 loc::ConcreteInt makeIntLocVal(const llvm::APSInt &integer) { 248 return loc::ConcreteInt(BasicVals.getValue(integer)); 249 } 250 251 NonLoc makeIntVal(const llvm::APInt& integer, bool isUnsigned) { 252 return nonloc::ConcreteInt(BasicVals.getValue(integer, isUnsigned)); 253 } 254 255 DefinedSVal makeIntVal(uint64_t integer, QualType type) { 256 if (Loc::isLocType(type)) 257 return loc::ConcreteInt(BasicVals.getValue(integer, type)); 258 259 return nonloc::ConcreteInt(BasicVals.getValue(integer, type)); 260 } 261 262 NonLoc makeIntVal(uint64_t integer, bool isUnsigned) { 263 return nonloc::ConcreteInt(BasicVals.getIntValue(integer, isUnsigned)); 264 } 265 266 NonLoc makeIntValWithPtrWidth(uint64_t integer, bool isUnsigned) { 267 return nonloc::ConcreteInt( 268 BasicVals.getIntWithPtrWidth(integer, isUnsigned)); 269 } 270 271 NonLoc makeLocAsInteger(Loc loc, unsigned bits) { 272 return nonloc::LocAsInteger(BasicVals.getPersistentSValWithData(loc, bits)); 273 } 274 275 NonLoc makeNonLoc(const SymExpr *lhs, BinaryOperator::Opcode op, 276 const llvm::APSInt& rhs, QualType type); 277 278 NonLoc makeNonLoc(const llvm::APSInt& rhs, BinaryOperator::Opcode op, 279 const SymExpr *lhs, QualType type); 280 281 NonLoc makeNonLoc(const SymExpr *lhs, BinaryOperator::Opcode op, 282 const SymExpr *rhs, QualType type); 283 284 /// \brief Create a NonLoc value for cast. 285 NonLoc makeNonLoc(const SymExpr *operand, QualType fromTy, QualType toTy); 286 287 nonloc::ConcreteInt makeTruthVal(bool b, QualType type) { 288 return nonloc::ConcreteInt(BasicVals.getTruthValue(b, type)); 289 } 290 291 nonloc::ConcreteInt makeTruthVal(bool b) { 292 return nonloc::ConcreteInt(BasicVals.getTruthValue(b)); 293 } 294 295 Loc makeNull() { 296 return loc::ConcreteInt(BasicVals.getZeroWithPtrWidth()); 297 } 298 299 Loc makeLoc(SymbolRef sym) { 300 return loc::MemRegionVal(MemMgr.getSymbolicRegion(sym)); 301 } 302 303 Loc makeLoc(const MemRegion* region) { 304 return loc::MemRegionVal(region); 305 } 306 307 Loc makeLoc(const AddrLabelExpr *expr) { 308 return loc::GotoLabel(expr->getLabel()); 309 } 310 311 Loc makeLoc(const llvm::APSInt& integer) { 312 return loc::ConcreteInt(BasicVals.getValue(integer)); 313 } 314 315 /// Return a memory region for the 'this' object reference. 316 loc::MemRegionVal getCXXThis(const CXXMethodDecl *D, 317 const StackFrameContext *SFC); 318 319 /// Return a memory region for the 'this' object reference. 320 loc::MemRegionVal getCXXThis(const CXXRecordDecl *D, 321 const StackFrameContext *SFC); 322 }; 323 324 SValBuilder* createSimpleSValBuilder(llvm::BumpPtrAllocator &alloc, 325 ASTContext &context, 326 ProgramStateManager &stateMgr); 327 328 } // end GR namespace 329 330 } // end clang namespace 331 332 #endif 333
