| 1 | //=======- UncountedLambdaCapturesChecker.cpp --------------------*- C++ -*-==// |
| 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 | #include "ASTUtils.h" |
| 10 | #include "DiagOutputUtils.h" |
| 11 | #include "PtrTypesSemantics.h" |
| 12 | #include "clang/AST/DynamicRecursiveASTVisitor.h" |
| 13 | #include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h" |
| 14 | #include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h" |
| 15 | #include "clang/StaticAnalyzer/Core/BugReporter/BugType.h" |
| 16 | #include "clang/StaticAnalyzer/Core/Checker.h" |
| 17 | #include <optional> |
| 18 | |
| 19 | using namespace clang; |
| 20 | using namespace ento; |
| 21 | |
| 22 | namespace { |
| 23 | class RawPtrRefLambdaCapturesChecker |
| 24 | : public Checker<check::ASTDecl<TranslationUnitDecl>> { |
| 25 | private: |
| 26 | BugType Bug; |
| 27 | mutable BugReporter *BR = nullptr; |
| 28 | TrivialFunctionAnalysis TFA; |
| 29 | |
| 30 | protected: |
| 31 | mutable std::optional<RetainTypeChecker> RTC; |
| 32 | |
| 33 | public: |
| 34 | RawPtrRefLambdaCapturesChecker(const char *description) |
| 35 | : Bug(this, description, "WebKit coding guidelines" ) {} |
| 36 | |
| 37 | virtual std::optional<bool> isUnsafePtr(QualType) const = 0; |
| 38 | virtual bool isPtrType(const std::string &) const = 0; |
| 39 | virtual const char *ptrKind(QualType QT) const = 0; |
| 40 | |
| 41 | void checkASTDecl(const TranslationUnitDecl *TUD, AnalysisManager &MGR, |
| 42 | BugReporter &BRArg) const { |
| 43 | BR = &BRArg; |
| 44 | |
| 45 | // The calls to checkAST* from AnalysisConsumer don't |
| 46 | // visit template instantiations or lambda classes. We |
| 47 | // want to visit those, so we make our own RecursiveASTVisitor. |
| 48 | struct LocalVisitor : DynamicRecursiveASTVisitor { |
| 49 | const RawPtrRefLambdaCapturesChecker *Checker; |
| 50 | llvm::DenseSet<const DeclRefExpr *> DeclRefExprsToIgnore; |
| 51 | llvm::DenseSet<const LambdaExpr *> LambdasToIgnore; |
| 52 | llvm::DenseSet<const ValueDecl *> ProtectedThisDecls; |
| 53 | llvm::DenseSet<const CallExpr *> CallToIgnore; |
| 54 | llvm::DenseSet<const CXXConstructExpr *> ConstructToIgnore; |
| 55 | llvm::DenseMap<const VarDecl *, const LambdaExpr *> LambdaOwnerMap; |
| 56 | |
| 57 | QualType ClsType; |
| 58 | |
| 59 | explicit LocalVisitor(const RawPtrRefLambdaCapturesChecker *Checker) |
| 60 | : Checker(Checker) { |
| 61 | assert(Checker); |
| 62 | ShouldVisitTemplateInstantiations = true; |
| 63 | ShouldVisitImplicitCode = false; |
| 64 | } |
| 65 | |
| 66 | bool TraverseCXXMethodDecl(CXXMethodDecl *CXXMD) override { |
| 67 | llvm::SaveAndRestore SavedDecl(ClsType); |
| 68 | if (CXXMD->isInstance()) |
| 69 | ClsType = CXXMD->getThisType(); |
| 70 | return DynamicRecursiveASTVisitor::TraverseCXXMethodDecl(D: CXXMD); |
| 71 | } |
| 72 | |
| 73 | bool TraverseObjCMethodDecl(ObjCMethodDecl *OCMD) override { |
| 74 | llvm::SaveAndRestore SavedDecl(ClsType); |
| 75 | if (OCMD && OCMD->isInstanceMethod()) { |
| 76 | if (auto *ImplParamDecl = OCMD->getSelfDecl()) |
| 77 | ClsType = ImplParamDecl->getType(); |
| 78 | } |
| 79 | return DynamicRecursiveASTVisitor::TraverseObjCMethodDecl(D: OCMD); |
| 80 | } |
| 81 | |
| 82 | bool VisitTypedefDecl(TypedefDecl *TD) override { |
| 83 | if (Checker->RTC) |
| 84 | Checker->RTC->visitTypedef(TD); |
| 85 | return true; |
| 86 | } |
| 87 | |
| 88 | bool shouldCheckThis() { |
| 89 | auto result = |
| 90 | !ClsType.isNull() ? Checker->isUnsafePtr(ClsType) : std::nullopt; |
| 91 | return result && *result; |
| 92 | } |
| 93 | |
| 94 | bool VisitLambdaExpr(LambdaExpr *L) override { |
| 95 | if (LambdasToIgnore.contains(V: L)) |
| 96 | return true; |
| 97 | Checker->visitLambdaExpr(L, shouldCheckThis: shouldCheckThis() && !hasProtectedThis(L), |
| 98 | T: ClsType); |
| 99 | return true; |
| 100 | } |
| 101 | |
| 102 | bool VisitVarDecl(VarDecl *VD) override { |
| 103 | auto *Init = VD->getInit(); |
| 104 | if (!Init) |
| 105 | return true; |
| 106 | if (auto *L = dyn_cast_or_null<LambdaExpr>(Val: Init->IgnoreParenCasts())) { |
| 107 | LambdasToIgnore.insert(V: L); // Evaluate lambdas in VisitDeclRefExpr. |
| 108 | return true; |
| 109 | } |
| 110 | if (!VD->hasLocalStorage()) |
| 111 | return true; |
| 112 | if (auto *E = dyn_cast<ExprWithCleanups>(Val: Init)) |
| 113 | Init = E->getSubExpr(); |
| 114 | if (auto *E = dyn_cast<CXXBindTemporaryExpr>(Val: Init)) |
| 115 | Init = E->getSubExpr(); |
| 116 | if (auto *CE = dyn_cast<CallExpr>(Val: Init)) { |
| 117 | if (auto *Callee = CE->getDirectCallee()) { |
| 118 | auto FnName = safeGetName(ASTNode: Callee); |
| 119 | unsigned ArgCnt = CE->getNumArgs(); |
| 120 | if (FnName == "makeScopeExit" && ArgCnt == 1) { |
| 121 | auto *Arg = CE->getArg(Arg: 0); |
| 122 | if (auto *E = dyn_cast<MaterializeTemporaryExpr>(Val: Arg)) |
| 123 | Arg = E->getSubExpr(); |
| 124 | if (auto *L = dyn_cast<LambdaExpr>(Val: Arg)) { |
| 125 | LambdaOwnerMap.insert(KV: std::make_pair(x&: VD, y&: L)); |
| 126 | CallToIgnore.insert(V: CE); |
| 127 | LambdasToIgnore.insert(V: L); |
| 128 | } |
| 129 | } else if (FnName == "makeVisitor" ) { |
| 130 | for (unsigned ArgIndex = 0; ArgIndex < ArgCnt; ++ArgIndex) { |
| 131 | auto *Arg = CE->getArg(Arg: ArgIndex); |
| 132 | if (auto *E = dyn_cast<MaterializeTemporaryExpr>(Val: Arg)) |
| 133 | Arg = E->getSubExpr(); |
| 134 | if (auto *L = dyn_cast<LambdaExpr>(Val: Arg)) { |
| 135 | LambdaOwnerMap.insert(KV: std::make_pair(x&: VD, y&: L)); |
| 136 | CallToIgnore.insert(V: CE); |
| 137 | LambdasToIgnore.insert(V: L); |
| 138 | } |
| 139 | } |
| 140 | } |
| 141 | } |
| 142 | } else if (auto *CE = dyn_cast<CXXConstructExpr>(Val: Init)) { |
| 143 | if (auto *Ctor = CE->getConstructor()) { |
| 144 | if (auto *Cls = Ctor->getParent()) { |
| 145 | auto FnName = safeGetName(ASTNode: Cls); |
| 146 | unsigned ArgCnt = CE->getNumArgs(); |
| 147 | if (FnName == "ScopeExit" && ArgCnt == 1) { |
| 148 | auto *Arg = CE->getArg(Arg: 0); |
| 149 | if (auto *E = dyn_cast<MaterializeTemporaryExpr>(Val: Arg)) |
| 150 | Arg = E->getSubExpr(); |
| 151 | if (auto *L = dyn_cast<LambdaExpr>(Val: Arg)) { |
| 152 | LambdaOwnerMap.insert(KV: std::make_pair(x&: VD, y&: L)); |
| 153 | ConstructToIgnore.insert(V: CE); |
| 154 | LambdasToIgnore.insert(V: L); |
| 155 | } |
| 156 | } |
| 157 | } |
| 158 | } |
| 159 | } |
| 160 | return true; |
| 161 | } |
| 162 | |
| 163 | bool VisitDeclRefExpr(DeclRefExpr *DRE) override { |
| 164 | if (DeclRefExprsToIgnore.contains(V: DRE)) |
| 165 | return true; |
| 166 | auto *VD = dyn_cast_or_null<VarDecl>(Val: DRE->getDecl()); |
| 167 | if (!VD) |
| 168 | return true; |
| 169 | if (auto It = LambdaOwnerMap.find(Val: VD); It != LambdaOwnerMap.end()) { |
| 170 | auto *L = It->second; |
| 171 | Checker->visitLambdaExpr(L, shouldCheckThis: shouldCheckThis() && !hasProtectedThis(L), |
| 172 | T: ClsType); |
| 173 | return true; |
| 174 | } |
| 175 | auto *Init = VD->getInit(); |
| 176 | if (!Init) |
| 177 | return true; |
| 178 | auto *L = dyn_cast_or_null<LambdaExpr>(Val: Init->IgnoreParenCasts()); |
| 179 | if (!L) |
| 180 | return true; |
| 181 | LambdasToIgnore.insert(V: L); |
| 182 | Checker->visitLambdaExpr(L, shouldCheckThis: shouldCheckThis() && !hasProtectedThis(L), |
| 183 | T: ClsType); |
| 184 | return true; |
| 185 | } |
| 186 | |
| 187 | bool shouldTreatAllArgAsNoEscape(FunctionDecl *FDecl) { |
| 188 | std::string PreviousName = safeGetName(ASTNode: FDecl); |
| 189 | for (auto *Decl = FDecl->getParent(); Decl; Decl = Decl->getParent()) { |
| 190 | if (!isa<NamespaceDecl>(Val: Decl) && !isa<CXXRecordDecl>(Val: Decl)) |
| 191 | return false; |
| 192 | auto Name = safeGetName(ASTNode: Decl); |
| 193 | // WTF::switchOn(T, F... f) is a variadic template function and |
| 194 | // couldn't be annotated with NOESCAPE. We hard code it here to |
| 195 | // workaround that. |
| 196 | if (Name == "WTF" && PreviousName == "switchOn" ) |
| 197 | return true; |
| 198 | // Treat every argument of functions in std::ranges as noescape. |
| 199 | if (Name == "std" && PreviousName == "ranges" ) |
| 200 | return true; |
| 201 | PreviousName = Name; |
| 202 | } |
| 203 | return false; |
| 204 | } |
| 205 | |
| 206 | bool VisitCXXConstructExpr(CXXConstructExpr *CE) override { |
| 207 | if (ConstructToIgnore.contains(V: CE)) |
| 208 | return true; |
| 209 | if (auto *Callee = CE->getConstructor()) { |
| 210 | unsigned ArgIndex = 0; |
| 211 | for (auto *Param : Callee->parameters()) { |
| 212 | if (ArgIndex >= CE->getNumArgs()) |
| 213 | return true; |
| 214 | auto *Arg = CE->getArg(Arg: ArgIndex)->IgnoreParenCasts(); |
| 215 | if (auto *L = findLambdaInArg(E: Arg)) { |
| 216 | LambdasToIgnore.insert(V: L); |
| 217 | if (!Param->hasAttr<NoEscapeAttr>()) |
| 218 | Checker->visitLambdaExpr( |
| 219 | L, shouldCheckThis: shouldCheckThis() && !hasProtectedThis(L), T: ClsType); |
| 220 | } |
| 221 | ++ArgIndex; |
| 222 | } |
| 223 | } |
| 224 | return true; |
| 225 | } |
| 226 | |
| 227 | bool VisitCallExpr(CallExpr *CE) override { |
| 228 | if (CallToIgnore.contains(V: CE)) |
| 229 | return true; |
| 230 | checkCalleeLambda(CE); |
| 231 | if (auto *Callee = CE->getDirectCallee()) { |
| 232 | if (isVisitFunction(CallExpr: CE, FnDecl: Callee)) |
| 233 | return true; |
| 234 | checkParameters(CE, Callee); |
| 235 | } else if (auto *CalleeE = CE->getCallee()) { |
| 236 | if (auto *DRE = dyn_cast<DeclRefExpr>(Val: CalleeE->IgnoreParenCasts())) { |
| 237 | if (auto *Callee = dyn_cast_or_null<FunctionDecl>(Val: DRE->getDecl())) |
| 238 | checkParameters(CE, Callee); |
| 239 | } |
| 240 | } |
| 241 | return true; |
| 242 | } |
| 243 | |
| 244 | bool isVisitFunction(CallExpr *CallExpr, FunctionDecl *FnDecl) { |
| 245 | bool IsVisitFn = safeGetName(ASTNode: FnDecl) == "visit" ; |
| 246 | if (!IsVisitFn) |
| 247 | return false; |
| 248 | bool ArgCnt = CallExpr->getNumArgs(); |
| 249 | if (!ArgCnt) |
| 250 | return false; |
| 251 | auto *Ns = FnDecl->getParent(); |
| 252 | if (!Ns) |
| 253 | return false; |
| 254 | auto NsName = safeGetName(ASTNode: Ns); |
| 255 | if (NsName != "WTF" && NsName != "std" ) |
| 256 | return false; |
| 257 | auto *Arg = CallExpr->getArg(Arg: 0); |
| 258 | if (!Arg) |
| 259 | return false; |
| 260 | auto *DRE = dyn_cast<DeclRefExpr>(Val: Arg->IgnoreParenCasts()); |
| 261 | if (!DRE) |
| 262 | return false; |
| 263 | auto *VD = dyn_cast<VarDecl>(Val: DRE->getDecl()); |
| 264 | if (!VD) |
| 265 | return false; |
| 266 | if (!LambdaOwnerMap.contains(Val: VD)) |
| 267 | return false; |
| 268 | DeclRefExprsToIgnore.insert(V: DRE); |
| 269 | return true; |
| 270 | } |
| 271 | |
| 272 | void checkParameters(CallExpr *CE, FunctionDecl *Callee) { |
| 273 | unsigned ArgIndex = isa<CXXOperatorCallExpr>(Val: CE); |
| 274 | bool TreatAllArgsAsNoEscape = shouldTreatAllArgAsNoEscape(FDecl: Callee); |
| 275 | for (auto *Param : Callee->parameters()) { |
| 276 | if (ArgIndex >= CE->getNumArgs()) |
| 277 | return; |
| 278 | auto *Arg = CE->getArg(Arg: ArgIndex)->IgnoreParenCasts(); |
| 279 | if (auto *L = findLambdaInArg(E: Arg)) { |
| 280 | LambdasToIgnore.insert(V: L); |
| 281 | if (!Param->hasAttr<NoEscapeAttr>() && !TreatAllArgsAsNoEscape) |
| 282 | Checker->visitLambdaExpr( |
| 283 | L, shouldCheckThis: shouldCheckThis() && !hasProtectedThis(L), T: ClsType); |
| 284 | } |
| 285 | ++ArgIndex; |
| 286 | } |
| 287 | } |
| 288 | |
| 289 | LambdaExpr *findLambdaInArg(Expr *E) { |
| 290 | if (auto *Lambda = dyn_cast_or_null<LambdaExpr>(Val: E)) |
| 291 | return Lambda; |
| 292 | auto *TempExpr = dyn_cast_or_null<CXXBindTemporaryExpr>(Val: E); |
| 293 | if (!TempExpr) |
| 294 | return nullptr; |
| 295 | E = TempExpr->getSubExpr()->IgnoreParenCasts(); |
| 296 | if (!E) |
| 297 | return nullptr; |
| 298 | if (auto *Lambda = dyn_cast<LambdaExpr>(Val: E)) |
| 299 | return Lambda; |
| 300 | auto *CE = dyn_cast_or_null<CXXConstructExpr>(Val: E); |
| 301 | if (!CE || !CE->getNumArgs()) |
| 302 | return nullptr; |
| 303 | auto *CtorArg = CE->getArg(Arg: 0)->IgnoreParenCasts(); |
| 304 | if (!CtorArg) |
| 305 | return nullptr; |
| 306 | auto *InnerCE = dyn_cast_or_null<CXXConstructExpr>(Val: CtorArg); |
| 307 | if (InnerCE && InnerCE->getNumArgs()) |
| 308 | CtorArg = InnerCE->getArg(Arg: 0)->IgnoreParenCasts(); |
| 309 | auto updateIgnoreList = [&] { |
| 310 | ConstructToIgnore.insert(V: CE); |
| 311 | if (InnerCE) |
| 312 | ConstructToIgnore.insert(V: InnerCE); |
| 313 | }; |
| 314 | if (auto *Lambda = dyn_cast<LambdaExpr>(Val: CtorArg)) { |
| 315 | updateIgnoreList(); |
| 316 | return Lambda; |
| 317 | } |
| 318 | if (auto *TempExpr = dyn_cast<CXXBindTemporaryExpr>(Val: CtorArg)) { |
| 319 | E = TempExpr->getSubExpr()->IgnoreParenCasts(); |
| 320 | if (auto *Lambda = dyn_cast<LambdaExpr>(Val: E)) { |
| 321 | updateIgnoreList(); |
| 322 | return Lambda; |
| 323 | } |
| 324 | } |
| 325 | auto *DRE = dyn_cast<DeclRefExpr>(Val: CtorArg); |
| 326 | if (!DRE) |
| 327 | return nullptr; |
| 328 | auto *VD = dyn_cast_or_null<VarDecl>(Val: DRE->getDecl()); |
| 329 | if (!VD) |
| 330 | return nullptr; |
| 331 | auto *Init = VD->getInit(); |
| 332 | if (!Init) |
| 333 | return nullptr; |
| 334 | if (auto *Lambda = dyn_cast<LambdaExpr>(Val: Init)) { |
| 335 | DeclRefExprsToIgnore.insert(V: DRE); |
| 336 | updateIgnoreList(); |
| 337 | return Lambda; |
| 338 | } |
| 339 | return nullptr; |
| 340 | } |
| 341 | |
| 342 | void checkCalleeLambda(CallExpr *CE) { |
| 343 | auto *Callee = CE->getCallee(); |
| 344 | if (!Callee) |
| 345 | return; |
| 346 | Callee = Callee->IgnoreParenCasts(); |
| 347 | if (auto *MTE = dyn_cast<MaterializeTemporaryExpr>(Val: Callee)) { |
| 348 | Callee = MTE->getSubExpr(); |
| 349 | if (!Callee) |
| 350 | return; |
| 351 | Callee = Callee->IgnoreParenCasts(); |
| 352 | } |
| 353 | if (auto *L = dyn_cast<LambdaExpr>(Val: Callee)) { |
| 354 | LambdasToIgnore.insert(V: L); // Calling a lambda upon creation is safe. |
| 355 | return; |
| 356 | } |
| 357 | auto *DRE = dyn_cast<DeclRefExpr>(Val: Callee->IgnoreParenCasts()); |
| 358 | if (!DRE) |
| 359 | return; |
| 360 | auto *MD = dyn_cast_or_null<CXXMethodDecl>(Val: DRE->getDecl()); |
| 361 | if (!MD || CE->getNumArgs() < 1) |
| 362 | return; |
| 363 | auto *Arg = CE->getArg(Arg: 0)->IgnoreParenCasts(); |
| 364 | if (auto *L = dyn_cast_or_null<LambdaExpr>(Val: Arg)) { |
| 365 | LambdasToIgnore.insert(V: L); // Calling a lambda upon creation is safe. |
| 366 | return; |
| 367 | } |
| 368 | auto *ArgRef = dyn_cast<DeclRefExpr>(Val: Arg); |
| 369 | if (!ArgRef) |
| 370 | return; |
| 371 | auto *VD = dyn_cast_or_null<VarDecl>(Val: ArgRef->getDecl()); |
| 372 | if (!VD) |
| 373 | return; |
| 374 | auto *Init = VD->getInit(); |
| 375 | if (!Init) |
| 376 | return; |
| 377 | auto *L = dyn_cast_or_null<LambdaExpr>(Val: Init->IgnoreParenCasts()); |
| 378 | if (!L) |
| 379 | return; |
| 380 | DeclRefExprsToIgnore.insert(V: ArgRef); |
| 381 | LambdasToIgnore.insert(V: L); |
| 382 | } |
| 383 | |
| 384 | bool hasProtectedThis(const LambdaExpr *L) { |
| 385 | for (const LambdaCapture &OtherCapture : L->captures()) { |
| 386 | if (!OtherCapture.capturesVariable()) |
| 387 | continue; |
| 388 | if (auto *ValueDecl = OtherCapture.getCapturedVar()) { |
| 389 | if (declProtectsThis(ValueDecl)) { |
| 390 | ProtectedThisDecls.insert(V: ValueDecl); |
| 391 | return true; |
| 392 | } |
| 393 | } |
| 394 | } |
| 395 | return false; |
| 396 | } |
| 397 | |
| 398 | bool declProtectsThis(const ValueDecl *ValueDecl) const { |
| 399 | auto *VD = dyn_cast<VarDecl>(Val: ValueDecl); |
| 400 | if (!VD) |
| 401 | return false; |
| 402 | auto *Init = VD->getInit(); |
| 403 | if (!Init) |
| 404 | return false; |
| 405 | const Expr *Arg = Init->IgnoreParenCasts(); |
| 406 | do { |
| 407 | if (auto *BTE = dyn_cast<CXXBindTemporaryExpr>(Val: Arg)) |
| 408 | Arg = BTE->getSubExpr()->IgnoreParenCasts(); |
| 409 | if (auto *CE = dyn_cast<CXXConstructExpr>(Val: Arg)) { |
| 410 | auto *Ctor = CE->getConstructor(); |
| 411 | if (!Ctor) |
| 412 | return false; |
| 413 | auto clsName = safeGetName(ASTNode: Ctor->getParent()); |
| 414 | if (Checker->isPtrType(clsName) && CE->getNumArgs()) { |
| 415 | Arg = CE->getArg(Arg: 0)->IgnoreParenCasts(); |
| 416 | continue; |
| 417 | } |
| 418 | if (auto *Type = ClsType.getTypePtrOrNull()) { |
| 419 | if (auto *CXXR = Type->getPointeeCXXRecordDecl()) { |
| 420 | if (CXXR == Ctor->getParent() && Ctor->isMoveConstructor() && |
| 421 | CE->getNumArgs() == 1) { |
| 422 | Arg = CE->getArg(Arg: 0)->IgnoreParenCasts(); |
| 423 | continue; |
| 424 | } |
| 425 | } |
| 426 | } |
| 427 | return false; |
| 428 | } |
| 429 | if (auto *CE = dyn_cast<CallExpr>(Val: Arg)) { |
| 430 | if (auto *Callee = CE->getDirectCallee()) { |
| 431 | if ((isStdOrWTFMove(F: Callee) || isCtorOfSafePtr(F: Callee)) && |
| 432 | CE->getNumArgs() == 1) { |
| 433 | Arg = CE->getArg(Arg: 0)->IgnoreParenCasts(); |
| 434 | continue; |
| 435 | } |
| 436 | } |
| 437 | } |
| 438 | if (auto *OpCE = dyn_cast<CXXOperatorCallExpr>(Val: Arg)) { |
| 439 | auto OpCode = OpCE->getOperator(); |
| 440 | if (OpCode == OO_Star || OpCode == OO_Amp) { |
| 441 | auto *Callee = OpCE->getDirectCallee(); |
| 442 | if (!Callee) |
| 443 | return false; |
| 444 | auto clsName = safeGetName(ASTNode: Callee->getParent()); |
| 445 | if (!Checker->isPtrType(clsName) || !OpCE->getNumArgs()) |
| 446 | return false; |
| 447 | Arg = OpCE->getArg(Arg: 0)->IgnoreParenCasts(); |
| 448 | continue; |
| 449 | } |
| 450 | } |
| 451 | if (auto *UO = dyn_cast<UnaryOperator>(Val: Arg)) { |
| 452 | auto OpCode = UO->getOpcode(); |
| 453 | if (OpCode == UO_Deref || OpCode == UO_AddrOf) { |
| 454 | Arg = UO->getSubExpr()->IgnoreParenCasts(); |
| 455 | continue; |
| 456 | } |
| 457 | } |
| 458 | break; |
| 459 | } while (Arg); |
| 460 | if (auto *DRE = dyn_cast<DeclRefExpr>(Val: Arg)) { |
| 461 | auto *Decl = DRE->getDecl(); |
| 462 | if (auto *ImplicitParam = dyn_cast<ImplicitParamDecl>(Val: Decl)) { |
| 463 | auto kind = ImplicitParam->getParameterKind(); |
| 464 | return kind == ImplicitParamKind::ObjCSelf || |
| 465 | kind == ImplicitParamKind::CXXThis; |
| 466 | } |
| 467 | return ProtectedThisDecls.contains(V: Decl); |
| 468 | } |
| 469 | return isa<CXXThisExpr>(Val: Arg); |
| 470 | } |
| 471 | }; |
| 472 | |
| 473 | LocalVisitor visitor(this); |
| 474 | if (RTC) |
| 475 | RTC->visitTranslationUnitDecl(TUD); |
| 476 | visitor.TraverseDecl(D: const_cast<TranslationUnitDecl *>(TUD)); |
| 477 | } |
| 478 | |
| 479 | void visitLambdaExpr(const LambdaExpr *L, bool shouldCheckThis, |
| 480 | const QualType T, |
| 481 | bool ignoreParamVarDecl = false) const { |
| 482 | if (TFA.isTrivial(S: L->getBody())) |
| 483 | return; |
| 484 | for (const LambdaCapture &C : L->captures()) { |
| 485 | if (C.capturesVariable()) { |
| 486 | ValueDecl *CapturedVar = C.getCapturedVar(); |
| 487 | if (ignoreParamVarDecl && isa<ParmVarDecl>(Val: CapturedVar)) |
| 488 | continue; |
| 489 | if (auto *ImplicitParam = dyn_cast<ImplicitParamDecl>(Val: CapturedVar)) { |
| 490 | auto kind = ImplicitParam->getParameterKind(); |
| 491 | if ((kind == ImplicitParamKind::ObjCSelf || |
| 492 | kind == ImplicitParamKind::CXXThis) && |
| 493 | !shouldCheckThis) |
| 494 | continue; |
| 495 | } |
| 496 | QualType CapturedVarQualType = CapturedVar->getType(); |
| 497 | auto IsUncountedPtr = isUnsafePtr(CapturedVar->getType()); |
| 498 | if (C.getCaptureKind() == LCK_ByCopy && |
| 499 | CapturedVarQualType->isReferenceType()) |
| 500 | continue; |
| 501 | if (IsUncountedPtr && *IsUncountedPtr) |
| 502 | reportBug(Capture: C, CapturedVar, T: CapturedVarQualType, L); |
| 503 | } else if (C.capturesThis() && shouldCheckThis) { |
| 504 | if (ignoreParamVarDecl) // this is always a parameter to this function. |
| 505 | continue; |
| 506 | reportBugOnThisPtr(Capture: C, T); |
| 507 | } |
| 508 | } |
| 509 | } |
| 510 | |
| 511 | void reportBug(const LambdaCapture &Capture, ValueDecl *CapturedVar, |
| 512 | const QualType T, const LambdaExpr *L) const { |
| 513 | assert(CapturedVar); |
| 514 | |
| 515 | auto Location = Capture.getLocation(); |
| 516 | if (isa<ImplicitParamDecl>(Val: CapturedVar) && !Location.isValid()) |
| 517 | Location = L->getBeginLoc(); |
| 518 | |
| 519 | SmallString<100> Buf; |
| 520 | llvm::raw_svector_ostream Os(Buf); |
| 521 | |
| 522 | if (Capture.isExplicit()) { |
| 523 | Os << "Captured " ; |
| 524 | } else { |
| 525 | Os << "Implicitly captured " ; |
| 526 | } |
| 527 | if (isa<PointerType>(Val: T) || isa<ObjCObjectPointerType>(Val: T)) { |
| 528 | Os << "raw-pointer " ; |
| 529 | } else { |
| 530 | Os << "reference " ; |
| 531 | } |
| 532 | |
| 533 | printQuotedQualifiedName(Os, D: CapturedVar); |
| 534 | Os << " to " << ptrKind(QT: T) << " type is unsafe." ; |
| 535 | |
| 536 | PathDiagnosticLocation BSLoc(Location, BR->getSourceManager()); |
| 537 | auto Report = std::make_unique<BasicBugReport>(args: Bug, args: Os.str(), args&: BSLoc); |
| 538 | BR->emitReport(R: std::move(Report)); |
| 539 | } |
| 540 | |
| 541 | void reportBugOnThisPtr(const LambdaCapture &Capture, |
| 542 | const QualType T) const { |
| 543 | SmallString<100> Buf; |
| 544 | llvm::raw_svector_ostream Os(Buf); |
| 545 | |
| 546 | if (Capture.isExplicit()) { |
| 547 | Os << "Captured " ; |
| 548 | } else { |
| 549 | Os << "Implicitly captured " ; |
| 550 | } |
| 551 | |
| 552 | Os << "raw-pointer 'this' to " << ptrKind(QT: T) << " type is unsafe." ; |
| 553 | |
| 554 | PathDiagnosticLocation BSLoc(Capture.getLocation(), BR->getSourceManager()); |
| 555 | auto Report = std::make_unique<BasicBugReport>(args: Bug, args: Os.str(), args&: BSLoc); |
| 556 | BR->emitReport(R: std::move(Report)); |
| 557 | } |
| 558 | }; |
| 559 | |
| 560 | class UncountedLambdaCapturesChecker : public RawPtrRefLambdaCapturesChecker { |
| 561 | public: |
| 562 | UncountedLambdaCapturesChecker() |
| 563 | : RawPtrRefLambdaCapturesChecker("Lambda capture of uncounted or " |
| 564 | "unchecked variable" ) {} |
| 565 | |
| 566 | std::optional<bool> isUnsafePtr(QualType QT) const final { |
| 567 | auto result1 = isUncountedPtr(T: QT); |
| 568 | auto result2 = isUncheckedPtr(T: QT); |
| 569 | if (result1 && *result1) |
| 570 | return true; |
| 571 | if (result2 && *result2) |
| 572 | return true; |
| 573 | if (result1) |
| 574 | return *result1; |
| 575 | return result2; |
| 576 | } |
| 577 | |
| 578 | virtual bool isPtrType(const std::string &Name) const final { |
| 579 | return isRefType(Name) || isCheckedPtr(Name); |
| 580 | } |
| 581 | |
| 582 | const char *ptrKind(QualType QT) const final { |
| 583 | if (isUncounted(T: QT)) |
| 584 | return "uncounted" ; |
| 585 | return "unchecked" ; |
| 586 | } |
| 587 | }; |
| 588 | |
| 589 | class UnretainedLambdaCapturesChecker : public RawPtrRefLambdaCapturesChecker { |
| 590 | public: |
| 591 | UnretainedLambdaCapturesChecker() |
| 592 | : RawPtrRefLambdaCapturesChecker("Lambda capture of unretained " |
| 593 | "variables" ) { |
| 594 | RTC = RetainTypeChecker(); |
| 595 | } |
| 596 | |
| 597 | std::optional<bool> isUnsafePtr(QualType QT) const final { |
| 598 | if (QT.hasStrongOrWeakObjCLifetime()) |
| 599 | return false; |
| 600 | return RTC->isUnretained(QT); |
| 601 | } |
| 602 | |
| 603 | virtual bool isPtrType(const std::string &Name) const final { |
| 604 | return isRetainPtrOrOSPtr(Name); |
| 605 | } |
| 606 | |
| 607 | const char *ptrKind(QualType QT) const final { return "unretained" ; } |
| 608 | }; |
| 609 | |
| 610 | } // namespace |
| 611 | |
| 612 | void ento::registerUncountedLambdaCapturesChecker(CheckerManager &Mgr) { |
| 613 | Mgr.registerChecker<UncountedLambdaCapturesChecker>(); |
| 614 | } |
| 615 | |
| 616 | bool ento::shouldRegisterUncountedLambdaCapturesChecker( |
| 617 | const CheckerManager &mgr) { |
| 618 | return true; |
| 619 | } |
| 620 | |
| 621 | void ento::registerUnretainedLambdaCapturesChecker(CheckerManager &Mgr) { |
| 622 | Mgr.registerChecker<UnretainedLambdaCapturesChecker>(); |
| 623 | } |
| 624 | |
| 625 | bool ento::shouldRegisterUnretainedLambdaCapturesChecker( |
| 626 | const CheckerManager &mgr) { |
| 627 | return true; |
| 628 | } |
| 629 | |