| //===--- BoolPointerImplicitConversionCheck.cpp - clang-tidy --------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "BoolPointerImplicitConversionCheck.h" |
| |
| using namespace clang::ast_matchers; |
| |
| namespace clang { |
| namespace tidy { |
| namespace bugprone { |
| |
| void BoolPointerImplicitConversionCheck::registerMatchers(MatchFinder *Finder) { |
| // Look for ifs that have an implicit bool* to bool conversion in the |
| // condition. Filter negations. |
| Finder->addMatcher( |
| ifStmt(hasCondition(findAll(implicitCastExpr( |
| unless(hasParent(unaryOperator(hasOperatorName("!")))), |
| hasSourceExpression( |
| expr(hasType(pointerType(pointee(booleanType()))), |
| ignoringParenImpCasts(declRefExpr().bind("expr")))), |
| hasCastKind(CK_PointerToBoolean)))), |
| unless(isInTemplateInstantiation())) |
| .bind("if"), |
| this); |
| } |
| |
| void BoolPointerImplicitConversionCheck::check( |
| const MatchFinder::MatchResult &Result) { |
| auto *If = Result.Nodes.getNodeAs<IfStmt>("if"); |
| auto *Var = Result.Nodes.getNodeAs<DeclRefExpr>("expr"); |
| |
| // Ignore macros. |
| if (Var->getBeginLoc().isMacroID()) |
| return; |
| |
| // Only allow variable accesses for now, no function calls or member exprs. |
| // Check that we don't dereference the variable anywhere within the if. This |
| // avoids false positives for checks of the pointer for nullptr before it is |
| // dereferenced. If there is a dereferencing operator on this variable don't |
| // emit a diagnostic. Also ignore array subscripts. |
| const Decl *D = Var->getDecl(); |
| auto DeclRef = ignoringParenImpCasts(declRefExpr(to(equalsNode(D)))); |
| if (!match(findAll( |
| unaryOperator(hasOperatorName("*"), hasUnaryOperand(DeclRef))), |
| *If, *Result.Context) |
| .empty() || |
| !match(findAll(arraySubscriptExpr(hasBase(DeclRef))), *If, |
| *Result.Context) |
| .empty() || |
| // FIXME: We should still warn if the paremater is implicitly converted to |
| // bool. |
| !match(findAll(callExpr(hasAnyArgument(ignoringParenImpCasts(DeclRef)))), |
| *If, *Result.Context) |
| .empty() || |
| !match(findAll(cxxDeleteExpr(has(ignoringParenImpCasts(expr(DeclRef))))), |
| *If, *Result.Context) |
| .empty()) |
| return; |
| |
| diag(Var->getBeginLoc(), "dubious check of 'bool *' against 'nullptr', did " |
| "you mean to dereference it?") |
| << FixItHint::CreateInsertion(Var->getBeginLoc(), "*"); |
| } |
| |
| } // namespace bugprone |
| } // namespace tidy |
| } // namespace clang |