1 //===-- SVals.cpp - Abstract RValues for Path-Sens. Value Tracking --------===// 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 SVal, Loc, and NonLoc, classes that represent 10 // abstract r-values for use with path-sensitive value tracking. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "clang/StaticAnalyzer/Core/PathSensitive/SVals.h" 15 #include "clang/AST/Decl.h" 16 #include "clang/AST/DeclCXX.h" 17 #include "clang/AST/Expr.h" 18 #include "clang/AST/Type.h" 19 #include "clang/Basic/JsonSupport.h" 20 #include "clang/Basic/LLVM.h" 21 #include "clang/StaticAnalyzer/Core/PathSensitive/BasicValueFactory.h" 22 #include "clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h" 23 #include "clang/StaticAnalyzer/Core/PathSensitive/SValBuilder.h" 24 #include "clang/StaticAnalyzer/Core/PathSensitive/SymExpr.h" 25 #include "clang/StaticAnalyzer/Core/PathSensitive/SymbolManager.h" 26 #include "llvm/ADT/Optional.h" 27 #include "llvm/Support/Casting.h" 28 #include "llvm/Support/Compiler.h" 29 #include "llvm/Support/ErrorHandling.h" 30 #include "llvm/Support/raw_ostream.h" 31 #include <cassert> 32 33 using namespace clang; 34 using namespace ento; 35 36 //===----------------------------------------------------------------------===// 37 // Symbol iteration within an SVal. 38 //===----------------------------------------------------------------------===// 39 40 //===----------------------------------------------------------------------===// 41 // Utility methods. 42 //===----------------------------------------------------------------------===// 43 44 bool SVal::hasConjuredSymbol() const { 45 if (Optional<nonloc::SymbolVal> SV = getAs<nonloc::SymbolVal>()) { 46 SymbolRef sym = SV->getSymbol(); 47 if (isa<SymbolConjured>(sym)) 48 return true; 49 } 50 51 if (Optional<loc::MemRegionVal> RV = getAs<loc::MemRegionVal>()) { 52 const MemRegion *R = RV->getRegion(); 53 if (const auto *SR = dyn_cast<SymbolicRegion>(R)) { 54 SymbolRef sym = SR->getSymbol(); 55 if (isa<SymbolConjured>(sym)) 56 return true; 57 } 58 } 59 60 return false; 61 } 62 63 const FunctionDecl *SVal::getAsFunctionDecl() const { 64 if (Optional<loc::MemRegionVal> X = getAs<loc::MemRegionVal>()) { 65 const MemRegion* R = X->getRegion(); 66 if (const FunctionCodeRegion *CTR = R->getAs<FunctionCodeRegion>()) 67 if (const auto *FD = dyn_cast<FunctionDecl>(CTR->getDecl())) 68 return FD; 69 } 70 71 if (auto X = getAs<nonloc::PointerToMember>()) { 72 if (const auto *MD = dyn_cast_or_null<CXXMethodDecl>(X->getDecl())) 73 return MD; 74 } 75 return nullptr; 76 } 77 78 /// If this SVal is a location (subclasses Loc) and wraps a symbol, 79 /// return that SymbolRef. Otherwise return 0. 80 /// 81 /// Implicit casts (ex: void* -> char*) can turn Symbolic region into Element 82 /// region. If that is the case, gets the underlining region. 83 /// When IncludeBaseRegions is set to true and the SubRegion is non-symbolic, 84 /// the first symbolic parent region is returned. 85 SymbolRef SVal::getAsLocSymbol(bool IncludeBaseRegions) const { 86 // FIXME: should we consider SymbolRef wrapped in CodeTextRegion? 87 if (const MemRegion *R = getAsRegion()) 88 if (const SymbolicRegion *SymR = 89 IncludeBaseRegions ? R->getSymbolicBase() 90 : dyn_cast<SymbolicRegion>(R->StripCasts())) 91 return SymR->getSymbol(); 92 93 return nullptr; 94 } 95 96 /// Get the symbol in the SVal or its base region. 97 SymbolRef SVal::getLocSymbolInBase() const { 98 Optional<loc::MemRegionVal> X = getAs<loc::MemRegionVal>(); 99 100 if (!X) 101 return nullptr; 102 103 const MemRegion *R = X->getRegion(); 104 105 while (const auto *SR = dyn_cast<SubRegion>(R)) { 106 if (const auto *SymR = dyn_cast<SymbolicRegion>(SR)) 107 return SymR->getSymbol(); 108 else 109 R = SR->getSuperRegion(); 110 } 111 112 return nullptr; 113 } 114 115 /// If this SVal wraps a symbol return that SymbolRef. 116 /// Otherwise, return 0. 117 /// 118 /// Casts are ignored during lookup. 119 /// \param IncludeBaseRegions The boolean that controls whether the search 120 /// should continue to the base regions if the region is not symbolic. 121 SymbolRef SVal::getAsSymbol(bool IncludeBaseRegions) const { 122 // FIXME: should we consider SymbolRef wrapped in CodeTextRegion? 123 if (Optional<nonloc::SymbolVal> X = getAs<nonloc::SymbolVal>()) 124 return X->getSymbol(); 125 126 return getAsLocSymbol(IncludeBaseRegions); 127 } 128 129 const MemRegion *SVal::getAsRegion() const { 130 if (Optional<loc::MemRegionVal> X = getAs<loc::MemRegionVal>()) 131 return X->getRegion(); 132 133 if (Optional<nonloc::LocAsInteger> X = getAs<nonloc::LocAsInteger>()) 134 return X->getLoc().getAsRegion(); 135 136 return nullptr; 137 } 138 139 const MemRegion *loc::MemRegionVal::stripCasts(bool StripBaseCasts) const { 140 const MemRegion *R = getRegion(); 141 return R ? R->StripCasts(StripBaseCasts) : nullptr; 142 } 143 144 const void *nonloc::LazyCompoundVal::getStore() const { 145 return static_cast<const LazyCompoundValData*>(Data)->getStore(); 146 } 147 148 const TypedValueRegion *nonloc::LazyCompoundVal::getRegion() const { 149 return static_cast<const LazyCompoundValData*>(Data)->getRegion(); 150 } 151 152 bool nonloc::PointerToMember::isNullMemberPointer() const { 153 return getPTMData().isNull(); 154 } 155 156 const NamedDecl *nonloc::PointerToMember::getDecl() const { 157 const auto PTMD = this->getPTMData(); 158 if (PTMD.isNull()) 159 return nullptr; 160 161 const NamedDecl *ND = nullptr; 162 if (PTMD.is<const NamedDecl *>()) 163 ND = PTMD.get<const NamedDecl *>(); 164 else 165 ND = PTMD.get<const PointerToMemberData *>()->getDeclaratorDecl(); 166 167 return ND; 168 } 169 170 //===----------------------------------------------------------------------===// 171 // Other Iterators. 172 //===----------------------------------------------------------------------===// 173 174 nonloc::CompoundVal::iterator nonloc::CompoundVal::begin() const { 175 return getValue()->begin(); 176 } 177 178 nonloc::CompoundVal::iterator nonloc::CompoundVal::end() const { 179 return getValue()->end(); 180 } 181 182 nonloc::PointerToMember::iterator nonloc::PointerToMember::begin() const { 183 const PTMDataType PTMD = getPTMData(); 184 if (PTMD.is<const NamedDecl *>()) 185 return {}; 186 return PTMD.get<const PointerToMemberData *>()->begin(); 187 } 188 189 nonloc::PointerToMember::iterator nonloc::PointerToMember::end() const { 190 const PTMDataType PTMD = getPTMData(); 191 if (PTMD.is<const NamedDecl *>()) 192 return {}; 193 return PTMD.get<const PointerToMemberData *>()->end(); 194 } 195 196 //===----------------------------------------------------------------------===// 197 // Useful predicates. 198 //===----------------------------------------------------------------------===// 199 200 bool SVal::isConstant() const { 201 return getAs<nonloc::ConcreteInt>() || getAs<loc::ConcreteInt>(); 202 } 203 204 bool SVal::isConstant(int I) const { 205 if (Optional<loc::ConcreteInt> LV = getAs<loc::ConcreteInt>()) 206 return LV->getValue() == I; 207 if (Optional<nonloc::ConcreteInt> NV = getAs<nonloc::ConcreteInt>()) 208 return NV->getValue() == I; 209 return false; 210 } 211 212 bool SVal::isZeroConstant() const { 213 return isConstant(0); 214 } 215 216 //===----------------------------------------------------------------------===// 217 // Transfer function dispatch for Non-Locs. 218 //===----------------------------------------------------------------------===// 219 220 SVal nonloc::ConcreteInt::evalBinOp(SValBuilder &svalBuilder, 221 BinaryOperator::Opcode Op, 222 const nonloc::ConcreteInt& R) const { 223 const llvm::APSInt* X = 224 svalBuilder.getBasicValueFactory().evalAPSInt(Op, getValue(), R.getValue()); 225 226 if (X) 227 return nonloc::ConcreteInt(*X); 228 else 229 return UndefinedVal(); 230 } 231 232 nonloc::ConcreteInt 233 nonloc::ConcreteInt::evalComplement(SValBuilder &svalBuilder) const { 234 return svalBuilder.makeIntVal(~getValue()); 235 } 236 237 nonloc::ConcreteInt 238 nonloc::ConcreteInt::evalMinus(SValBuilder &svalBuilder) const { 239 return svalBuilder.makeIntVal(-getValue()); 240 } 241 242 //===----------------------------------------------------------------------===// 243 // Transfer function dispatch for Locs. 244 //===----------------------------------------------------------------------===// 245 246 SVal loc::ConcreteInt::evalBinOp(BasicValueFactory& BasicVals, 247 BinaryOperator::Opcode Op, 248 const loc::ConcreteInt& R) const { 249 assert(BinaryOperator::isComparisonOp(Op) || Op == BO_Sub); 250 251 const llvm::APSInt *X = BasicVals.evalAPSInt(Op, getValue(), R.getValue()); 252 253 if (X) 254 return nonloc::ConcreteInt(*X); 255 else 256 return UndefinedVal(); 257 } 258 259 //===----------------------------------------------------------------------===// 260 // Pretty-Printing. 261 //===----------------------------------------------------------------------===// 262 263 LLVM_DUMP_METHOD void SVal::dump() const { dumpToStream(llvm::errs()); } 264 265 void SVal::printJson(raw_ostream &Out, bool AddQuotes) const { 266 std::string Buf; 267 llvm::raw_string_ostream TempOut(Buf); 268 269 dumpToStream(TempOut); 270 271 Out << JsonFormat(TempOut.str(), AddQuotes); 272 } 273 274 void SVal::dumpToStream(raw_ostream &os) const { 275 switch (getBaseKind()) { 276 case UnknownValKind: 277 os << "Unknown"; 278 break; 279 case NonLocKind: 280 castAs<NonLoc>().dumpToStream(os); 281 break; 282 case LocKind: 283 castAs<Loc>().dumpToStream(os); 284 break; 285 case UndefinedValKind: 286 os << "Undefined"; 287 break; 288 } 289 } 290 291 void NonLoc::dumpToStream(raw_ostream &os) const { 292 switch (getSubKind()) { 293 case nonloc::ConcreteIntKind: { 294 const auto &Value = castAs<nonloc::ConcreteInt>().getValue(); 295 os << Value << ' ' << (Value.isSigned() ? 'S' : 'U') 296 << Value.getBitWidth() << 'b'; 297 break; 298 } 299 case nonloc::SymbolValKind: 300 os << castAs<nonloc::SymbolVal>().getSymbol(); 301 break; 302 303 case nonloc::LocAsIntegerKind: { 304 const nonloc::LocAsInteger& C = castAs<nonloc::LocAsInteger>(); 305 os << C.getLoc() << " [as " << C.getNumBits() << " bit integer]"; 306 break; 307 } 308 case nonloc::CompoundValKind: { 309 const nonloc::CompoundVal& C = castAs<nonloc::CompoundVal>(); 310 os << "compoundVal{"; 311 bool first = true; 312 for (const auto &I : C) { 313 if (first) { 314 os << ' '; first = false; 315 } 316 else 317 os << ", "; 318 319 I.dumpToStream(os); 320 } 321 os << "}"; 322 break; 323 } 324 case nonloc::LazyCompoundValKind: { 325 const nonloc::LazyCompoundVal &C = castAs<nonloc::LazyCompoundVal>(); 326 os << "lazyCompoundVal{" << const_cast<void *>(C.getStore()) 327 << ',' << C.getRegion() 328 << '}'; 329 break; 330 } 331 case nonloc::PointerToMemberKind: { 332 os << "pointerToMember{"; 333 const nonloc::PointerToMember &CastRes = 334 castAs<nonloc::PointerToMember>(); 335 if (CastRes.getDecl()) 336 os << "|" << CastRes.getDecl()->getQualifiedNameAsString() << "|"; 337 bool first = true; 338 for (const auto &I : CastRes) { 339 if (first) { 340 os << ' '; first = false; 341 } 342 else 343 os << ", "; 344 345 os << (*I).getType().getAsString(); 346 } 347 348 os << '}'; 349 break; 350 } 351 default: 352 assert(false && "Pretty-printed not implemented for this NonLoc."); 353 break; 354 } 355 } 356 357 void Loc::dumpToStream(raw_ostream &os) const { 358 switch (getSubKind()) { 359 case loc::ConcreteIntKind: 360 os << castAs<loc::ConcreteInt>().getValue().getZExtValue() << " (Loc)"; 361 break; 362 case loc::GotoLabelKind: 363 os << "&&" << castAs<loc::GotoLabel>().getLabel()->getName(); 364 break; 365 case loc::MemRegionValKind: 366 os << '&' << castAs<loc::MemRegionVal>().getRegion()->getString(); 367 break; 368 default: 369 llvm_unreachable("Pretty-printing not implemented for this Loc."); 370 } 371 } 372
Indexes created Tue Feb 24 08:35:24 UTC 2026