| //===--- ProBoundsArrayToPointerDecayCheck.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 "ProBoundsArrayToPointerDecayCheck.h" |
| #include "clang/AST/ASTContext.h" |
| #include "clang/AST/ParentMapContext.h" |
| #include "clang/ASTMatchers/ASTMatchFinder.h" |
| |
| using namespace clang::ast_matchers; |
| |
| namespace clang { |
| namespace tidy { |
| namespace cppcoreguidelines { |
| |
| namespace { |
| AST_MATCHER_P(CXXForRangeStmt, hasRangeBeginEndStmt, |
| ast_matchers::internal::Matcher<DeclStmt>, InnerMatcher) { |
| for (const DeclStmt *Stmt : {Node.getBeginStmt(), Node.getEndStmt()}) |
| if (Stmt != nullptr && InnerMatcher.matches(*Stmt, Finder, Builder)) |
| return true; |
| return false; |
| } |
| |
| AST_MATCHER(Stmt, isInsideOfRangeBeginEndStmt) { |
| return stmt(hasAncestor(cxxForRangeStmt( |
| hasRangeBeginEndStmt(hasDescendant(equalsNode(&Node)))))) |
| .matches(Node, Finder, Builder); |
| } |
| |
| AST_MATCHER_P(Expr, hasParentIgnoringImpCasts, |
| ast_matchers::internal::Matcher<Expr>, InnerMatcher) { |
| const Expr *E = &Node; |
| do { |
| DynTypedNodeList Parents = Finder->getASTContext().getParents(*E); |
| if (Parents.size() != 1) |
| return false; |
| E = Parents[0].get<Expr>(); |
| if (!E) |
| return false; |
| } while (isa<ImplicitCastExpr>(E)); |
| |
| return InnerMatcher.matches(*E, Finder, Builder); |
| } |
| } // namespace |
| |
| void ProBoundsArrayToPointerDecayCheck::registerMatchers(MatchFinder *Finder) { |
| // The only allowed array to pointer decay |
| // 1) just before array subscription |
| // 2) inside a range-for over an array |
| // 3) if it converts a string literal to a pointer |
| Finder->addMatcher( |
| traverse(TK_AsIs, |
| implicitCastExpr( |
| unless(hasParent(arraySubscriptExpr())), |
| unless(hasParentIgnoringImpCasts(explicitCastExpr())), |
| unless(isInsideOfRangeBeginEndStmt()), |
| unless(hasSourceExpression(ignoringParens(stringLiteral())))) |
| .bind("cast")), |
| this); |
| } |
| |
| void ProBoundsArrayToPointerDecayCheck::check( |
| const MatchFinder::MatchResult &Result) { |
| const auto *MatchedCast = Result.Nodes.getNodeAs<ImplicitCastExpr>("cast"); |
| if (MatchedCast->getCastKind() != CK_ArrayToPointerDecay) |
| return; |
| |
| diag(MatchedCast->getExprLoc(), "do not implicitly decay an array into a " |
| "pointer; consider using gsl::array_view or " |
| "an explicit cast instead"); |
| } |
| |
| } // namespace cppcoreguidelines |
| } // namespace tidy |
| } // namespace clang |