Author: dcoughlin Date: Tue Nov 24 13:15:11 2015 New Revision: 254007 URL: http://llvm.org/viewvc/llvm-project?rev=254007&view=rev Log: [analyzer] Pass value expression for inlined defensive checks when binding null to nonnull.
The nullability checker was not suppressing false positives resulting from inlined defensive checks when null was bound to a nonnull variable because it was passing the entire bind statement rather than the value expression to trackNullOrUndefValue(). This commit changes that checker to synactically match on the bind statement to extract the value expression so it can be passed to trackNullOrUndefValue(). rdar://problem/23575439 Modified: cfe/trunk/lib/StaticAnalyzer/Checkers/NullabilityChecker.cpp cfe/trunk/test/Analysis/nullability.mm Modified: cfe/trunk/lib/StaticAnalyzer/Checkers/NullabilityChecker.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/StaticAnalyzer/Checkers/NullabilityChecker.cpp?rev=254007&r1=254006&r2=254007&view=diff ============================================================================== --- cfe/trunk/lib/StaticAnalyzer/Checkers/NullabilityChecker.cpp (original) +++ cfe/trunk/lib/StaticAnalyzer/Checkers/NullabilityChecker.cpp Tue Nov 24 13:15:11 2015 @@ -862,6 +862,30 @@ void NullabilityChecker::checkPostStmt(c } } +/// For a given statement performing a bind, attempt to syntactically +/// match the expression resulting in the bound value. +static const Expr * matchValueExprForBind(const Stmt *S) { + // For `x = e` the value expression is the right-hand side. + if (auto *BinOp = dyn_cast<BinaryOperator>(S)) { + if (BinOp->getOpcode() == BO_Assign) + return BinOp->getRHS(); + } + + // For `int x = e` the value expression is the initializer. + if (auto *DS = dyn_cast<DeclStmt>(S)) { + if (DS->isSingleDecl()) { + auto *VD = dyn_cast<VarDecl>(DS->getSingleDecl()); + if (!VD) + return nullptr; + + if (const Expr *Init = VD->getInit()) + return Init; + } + } + + return nullptr; +} + /// Propagate the nullability information through binds and warn when nullable /// pointer or null symbol is assigned to a pointer with a nonnull type. void NullabilityChecker::checkBind(SVal L, SVal V, const Stmt *S, @@ -898,8 +922,13 @@ void NullabilityChecker::checkBind(SVal ExplodedNode *N = C.generateErrorNode(State, &Tag); if (!N) return; + + const Stmt *ValueExpr = matchValueExprForBind(S); + if (!ValueExpr) + ValueExpr = S; + reportBugIfPreconditionHolds(ErrorKind::NilAssignedToNonnull, N, nullptr, C, - S); + ValueExpr); return; } // Intentionally missing case: '0' is bound to a reference. It is handled by Modified: cfe/trunk/test/Analysis/nullability.mm URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Analysis/nullability.mm?rev=254007&r1=254006&r2=254007&view=diff ============================================================================== --- cfe/trunk/test/Analysis/nullability.mm (original) +++ cfe/trunk/test/Analysis/nullability.mm Tue Nov 24 13:15:11 2015 @@ -238,6 +238,19 @@ Dummy *_Nonnull testDefensiveInlineCheck case 3: inlinedUnspecified(p); break; } if (getRandom()) - takesNonnull(p); + takesNonnull(p); // no-warning + + if (getRandom()) { + Dummy *_Nonnull varWithInitializer = p; // no-warning + + Dummy *_Nonnull var1WithInitializer = p, // no-warning + *_Nonnull var2WithInitializer = p; // no-warning + } + + if (getRandom()) { + Dummy *_Nonnull varWithoutInitializer; + varWithoutInitializer = p; // no-warning + } + return p; } _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits