| //===--- 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( |
| traverse( |
| TK_AsIs, |
| ifStmt( |
| hasCondition(findAll(implicitCastExpr( |
| unless(hasParent(unaryOperator(hasOperatorName("!")))), |
| hasSourceExpression(expr( |
| hasType(pointerType(pointee(booleanType()))), |
| ignoringParenImpCasts(anyOf(declRefExpr().bind("expr"), |
| memberExpr().bind("expr"))))), |
| hasCastKind(CK_PointerToBoolean)))), |
| unless(isInTemplateInstantiation())) |
| .bind("if")), |
| this); |
| } |
| |
| static void checkImpl(const MatchFinder::MatchResult &Result, const Expr *Ref, |
| const IfStmt *If, |
| const ast_matchers::internal::Matcher<Expr> &RefMatcher, |
| ClangTidyCheck &Check) { |
| // Ignore macros. |
| if (Ref->getBeginLoc().isMacroID()) |
| return; |
| |
| // Only allow variable accesses and member exprs for now, no function calls. |
| // 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. |
| if (!match(findAll(unaryOperator(hasOperatorName("*"), |
| hasUnaryOperand(RefMatcher))), |
| *If, *Result.Context) |
| .empty() || |
| !match(findAll(arraySubscriptExpr(hasBase(RefMatcher))), *If, |
| *Result.Context) |
| .empty() || |
| // FIXME: We should still warn if the paremater is implicitly converted to |
| // bool. |
| !match( |
| findAll(callExpr(hasAnyArgument(ignoringParenImpCasts(RefMatcher)))), |
| *If, *Result.Context) |
| .empty() || |
| !match( |
| findAll(cxxDeleteExpr(has(ignoringParenImpCasts(expr(RefMatcher))))), |
| *If, *Result.Context) |
| .empty()) |
| return; |
| |
| Check.diag(Ref->getBeginLoc(), |
| "dubious check of 'bool *' against 'nullptr', did " |
| "you mean to dereference it?") |
| << FixItHint::CreateInsertion(Ref->getBeginLoc(), "*"); |
| } |
| |
| void BoolPointerImplicitConversionCheck::check( |
| const MatchFinder::MatchResult &Result) { |
| const auto *If = Result.Nodes.getNodeAs<IfStmt>("if"); |
| if (const auto *E = Result.Nodes.getNodeAs<Expr>("expr")) { |
| const Decl *D = isa<DeclRefExpr>(E) ? cast<DeclRefExpr>(E)->getDecl() |
| : cast<MemberExpr>(E)->getMemberDecl(); |
| const auto M = |
| ignoringParenImpCasts(anyOf(declRefExpr(to(equalsNode(D))), |
| memberExpr(hasDeclaration(equalsNode(D))))); |
| checkImpl(Result, E, If, M, *this); |
| } |
| } |
| |
| } // namespace bugprone |
| } // namespace tidy |
| } // namespace clang |