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/Expr.h" 19 #include "clang/AST/ExprCXX.h" 20 #include "clang/AST/ExprObjC.h" 21 #include "clang/StaticAnalyzer/Core/PathSensitive/SVals.h" 22 #include "clang/StaticAnalyzer/Core/PathSensitive/BasicValueFactory.h" 23 #include "clang/StaticAnalyzer/Core/PathSensitive/MemRegion.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(Context), Sym2->getType(Context)); 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 (Ty2->isIntegerType() && Ty2->isIntegerType())); 82 } 83 84 SVal evalCast(SVal val, QualType castTy, QualType originalType); 85 86 virtual SVal evalMinus(NonLoc val) = 0; 87 88 virtual SVal evalComplement(NonLoc val) = 0; 89 90 /// Create a new value which represents a binary expression with two non 91 /// location operands. 92 virtual SVal evalBinOpNN(ProgramStateRef state, BinaryOperator::Opcode op, 93 NonLoc lhs, NonLoc rhs, QualType resultTy) = 0; 94 95 /// Create a new value which represents a binary expression with two memory 96 /// location operands. 97 virtual SVal evalBinOpLL(ProgramStateRef state, BinaryOperator::Opcode op, 98 Loc lhs, Loc rhs, QualType resultTy) = 0; 99 100 /// Create a new value which represents a binary expression with a memory 101 /// location and non location operands. For example, this would be used to 102 /// evaluate a pointer arithmetic operation. 103 virtual SVal evalBinOpLN(ProgramStateRef state, BinaryOperator::Opcode op, 104 Loc lhs, NonLoc rhs, QualType resultTy) = 0; 105 106 /// Evaluates a given SVal. If the SVal has only one possible (integer) value, 107 /// that value is returned. Otherwise, returns NULL. 108 virtual const llvm::APSInt *getKnownValue(ProgramStateRef state, SVal val) = 0; 109 110 /// Handles generation of the value in case the builder is not smart enough to 111 /// handle the given binary expression. Depending on the state, decides to 112 /// either keep the expression or forget the history and generate an 113 /// UnknownVal. 114 SVal makeGenericVal(ProgramStateRef state, BinaryOperator::Opcode op, 115 NonLoc lhs, NonLoc rhs, QualType resultTy); 116 117 SVal evalBinOp(ProgramStateRef state, BinaryOperator::Opcode op, 118 SVal lhs, SVal rhs, QualType type); 119 120 DefinedOrUnknownSVal evalEQ(ProgramStateRef state, DefinedOrUnknownSVal lhs, 121 DefinedOrUnknownSVal rhs); 122 123 ASTContext &getContext() { return Context; } 124 const ASTContext &getContext() const { return Context; } 125 126 ProgramStateManager &getStateManager() { return StateMgr; } 127 128 QualType getConditionType() const { 129 return getContext().IntTy; 130 } 131 132 QualType getArrayIndexType() const { 133 return ArrayIndexTy; 134 } 135 136 BasicValueFactory &getBasicValueFactory() { return BasicVals; } 137 const BasicValueFactory &getBasicValueFactory() const { return BasicVals; } 138 139 SymbolManager &getSymbolManager() { return SymMgr; } 140 const SymbolManager &getSymbolManager() const { return SymMgr; } 141 142 MemRegionManager &getRegionManager() { return MemMgr; } 143 const MemRegionManager &getRegionManager() const { return MemMgr; } 144 145 // Forwarding methods to SymbolManager. 146 147 const SymbolConjured* getConjuredSymbol(const Stmt *stmt, 148 const LocationContext *LCtx, 149 QualType type, 150 unsigned visitCount, 151 const void *symbolTag = 0) { 152 return SymMgr.getConjuredSymbol(stmt, LCtx, type, visitCount, symbolTag); 153 } 154 155 const SymbolConjured* getConjuredSymbol(const Expr *expr, 156 const LocationContext *LCtx, 157 unsigned visitCount, 158 const void *symbolTag = 0) { 159 return SymMgr.getConjuredSymbol(expr, LCtx, visitCount, symbolTag); 160 } 161 162 /// Construct an SVal representing '0' for the specified type. 163 DefinedOrUnknownSVal makeZeroVal(QualType type); 164 165 /// Make a unique symbol for value of region. 166 DefinedOrUnknownSVal getRegionValueSymbolVal(const TypedValueRegion *region); 167 168 /// \brief Create a new symbol with a unique 'name'. 169 /// 170 /// We resort to conjured symbols when we cannot construct a derived symbol. 171 /// The advantage of symbols derived/built from other symbols is that we 172 /// preserve the relation between related(or even equivalent) expressions, so 173 /// conjured symbols should be used sparingly. 174 DefinedOrUnknownSVal getConjuredSymbolVal(const void *symbolTag, 175 const Expr *expr, 176 const LocationContext *LCtx, 177 unsigned count); 178 DefinedOrUnknownSVal getConjuredSymbolVal(const void *symbolTag, 179 const Expr *expr, 180 const LocationContext *LCtx, 181 QualType type, 182 unsigned count); 183 184 DefinedOrUnknownSVal getConjuredSymbolVal(const Stmt *stmt, 185 const LocationContext *LCtx, 186 QualType type, 187 unsigned visitCount); 188 189 DefinedOrUnknownSVal getDerivedRegionValueSymbolVal( 190 SymbolRef parentSymbol, const TypedValueRegion *region); 191 192 DefinedSVal getMetadataSymbolVal( 193 const void *symbolTag, const MemRegion *region, 194 const Expr *expr, QualType type, unsigned count); 195 196 DefinedSVal getFunctionPointer(const FunctionDecl *func); 197 198 DefinedSVal getBlockPointer(const BlockDecl *block, CanQualType locTy, 199 const LocationContext *locContext); 200 201 NonLoc makeCompoundVal(QualType type, llvm::ImmutableList<SVal> vals) { 202 return nonloc::CompoundVal(BasicVals.getCompoundValData(type, vals)); 203 } 204 205 NonLoc makeLazyCompoundVal(const StoreRef &store, 206 const TypedValueRegion *region) { 207 return nonloc::LazyCompoundVal( 208 BasicVals.getLazyCompoundValData(store, region)); 209 } 210 211 NonLoc makeZeroArrayIndex() { 212 return nonloc::ConcreteInt(BasicVals.getValue(0, ArrayIndexTy)); 213 } 214 215 NonLoc makeArrayIndex(uint64_t idx) { 216 return nonloc::ConcreteInt(BasicVals.getValue(idx, ArrayIndexTy)); 217 } 218 219 SVal convertToArrayIndex(SVal val); 220 221 nonloc::ConcreteInt makeIntVal(const IntegerLiteral* integer) { 222 return nonloc::ConcreteInt( 223 BasicVals.getValue(integer->getValue(), 224 integer->getType()->isUnsignedIntegerOrEnumerationType())); 225 } 226 227 nonloc::ConcreteInt makeBoolVal(const ObjCBoolLiteralExpr *boolean) { 228 return makeTruthVal(boolean->getValue(), boolean->getType()); 229 } 230 231 nonloc::ConcreteInt makeBoolVal(const CXXBoolLiteralExpr *boolean); 232 233 nonloc::ConcreteInt makeIntVal(const llvm::APSInt& integer) { 234 return nonloc::ConcreteInt(BasicVals.getValue(integer)); 235 } 236 237 loc::ConcreteInt makeIntLocVal(const llvm::APSInt &integer) { 238 return loc::ConcreteInt(BasicVals.getValue(integer)); 239 } 240 241 NonLoc makeIntVal(const llvm::APInt& integer, bool isUnsigned) { 242 return nonloc::ConcreteInt(BasicVals.getValue(integer, isUnsigned)); 243 } 244 245 DefinedSVal makeIntVal(uint64_t integer, QualType type) { 246 if (Loc::isLocType(type)) 247 return loc::ConcreteInt(BasicVals.getValue(integer, type)); 248 249 return nonloc::ConcreteInt(BasicVals.getValue(integer, type)); 250 } 251 252 NonLoc makeIntVal(uint64_t integer, bool isUnsigned) { 253 return nonloc::ConcreteInt(BasicVals.getIntValue(integer, isUnsigned)); 254 } 255 256 NonLoc makeIntValWithPtrWidth(uint64_t integer, bool isUnsigned) { 257 return nonloc::ConcreteInt( 258 BasicVals.getIntWithPtrWidth(integer, isUnsigned)); 259 } 260 261 NonLoc makeIntVal(uint64_t integer, unsigned bitWidth, bool isUnsigned) { 262 return nonloc::ConcreteInt( 263 BasicVals.getValue(integer, bitWidth, isUnsigned)); 264 } 265 266 NonLoc makeLocAsInteger(Loc loc, unsigned bits) { 267 return nonloc::LocAsInteger(BasicVals.getPersistentSValWithData(loc, bits)); 268 } 269 270 NonLoc makeNonLoc(const SymExpr *lhs, BinaryOperator::Opcode op, 271 const llvm::APSInt& rhs, QualType type); 272 273 NonLoc makeNonLoc(const llvm::APSInt& rhs, BinaryOperator::Opcode op, 274 const SymExpr *lhs, QualType type); 275 276 NonLoc makeNonLoc(const SymExpr *lhs, BinaryOperator::Opcode op, 277 const SymExpr *rhs, QualType type); 278 279 /// \brief Create a NonLoc value for cast. 280 NonLoc makeNonLoc(const SymExpr *operand, QualType fromTy, QualType toTy); 281 282 nonloc::ConcreteInt makeTruthVal(bool b, QualType type) { 283 return nonloc::ConcreteInt(BasicVals.getTruthValue(b, type)); 284 } 285 286 nonloc::ConcreteInt makeTruthVal(bool b) { 287 return nonloc::ConcreteInt(BasicVals.getTruthValue(b)); 288 } 289 290 Loc makeNull() { 291 return loc::ConcreteInt(BasicVals.getZeroWithPtrWidth()); 292 } 293 294 Loc makeLoc(SymbolRef sym) { 295 return loc::MemRegionVal(MemMgr.getSymbolicRegion(sym)); 296 } 297 298 Loc makeLoc(const MemRegion* region) { 299 return loc::MemRegionVal(region); 300 } 301 302 Loc makeLoc(const AddrLabelExpr *expr) { 303 return loc::GotoLabel(expr->getLabel()); 304 } 305 306 Loc makeLoc(const llvm::APSInt& integer) { 307 return loc::ConcreteInt(BasicVals.getValue(integer)); 308 } 309 310 }; 311 312 SValBuilder* createSimpleSValBuilder(llvm::BumpPtrAllocator &alloc, 313 ASTContext &context, 314 ProgramStateManager &stateMgr); 315 316 } // end GR namespace 317 318 } // end clang namespace 319 320 #endif 321
