83 lines · cpp
1//===----------------------------------------------------------------------===//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-exception6//7//===----------------------------------------------------------------------===//8 9#include "ProBoundsArrayToPointerDecayCheck.h"10#include "clang/AST/ASTContext.h"11#include "clang/AST/ParentMapContext.h"12#include "clang/ASTMatchers/ASTMatchFinder.h"13#include "clang/ASTMatchers/ASTMatchers.h"14 15using namespace clang::ast_matchers;16 17namespace clang::tidy::cppcoreguidelines {18 19namespace {20AST_MATCHER_P(CXXForRangeStmt, hasRangeBeginEndStmt,21 ast_matchers::internal::Matcher<DeclStmt>, InnerMatcher) {22 for (const DeclStmt *Stmt : {Node.getBeginStmt(), Node.getEndStmt()})23 if (Stmt != nullptr && InnerMatcher.matches(*Stmt, Finder, Builder))24 return true;25 return false;26}27 28AST_MATCHER(Stmt, isInsideOfRangeBeginEndStmt) {29 return stmt(hasAncestor(cxxForRangeStmt(30 hasRangeBeginEndStmt(hasDescendant(equalsNode(&Node))))))31 .matches(Node, Finder, Builder);32}33 34AST_MATCHER_P(Expr, hasParentIgnoringImpCasts,35 ast_matchers::internal::Matcher<Expr>, InnerMatcher) {36 const Expr *E = &Node;37 do {38 const DynTypedNodeList Parents = Finder->getASTContext().getParents(*E);39 if (Parents.size() != 1)40 return false;41 E = Parents[0].get<Expr>();42 if (!E)43 return false;44 } while (isa<ImplicitCastExpr>(E));45 46 return InnerMatcher.matches(*E, Finder, Builder);47}48} // namespace49 50void ProBoundsArrayToPointerDecayCheck::registerMatchers(MatchFinder *Finder) {51 // The only allowed array to pointer decay52 // 1) just before array subscription53 // 2) inside a range-for over an array54 // 3) if it converts a string literal to a pointer55 Finder->addMatcher(56 traverse(57 TK_AsIs,58 implicitCastExpr(59 unless(hasParent(arraySubscriptExpr())),60 unless(hasSourceExpression(predefinedExpr())),61 unless(hasParentIgnoringImpCasts(explicitCastExpr())),62 unless(isInsideOfRangeBeginEndStmt()),63 unless(hasSourceExpression(ignoringParens(stringLiteral()))),64 unless(hasSourceExpression(ignoringParens(65 conditionalOperator(hasTrueExpression(stringLiteral()),66 hasFalseExpression(stringLiteral()))))))67 .bind("cast")),68 this);69}70 71void ProBoundsArrayToPointerDecayCheck::check(72 const MatchFinder::MatchResult &Result) {73 const auto *MatchedCast = Result.Nodes.getNodeAs<ImplicitCastExpr>("cast");74 if (MatchedCast->getCastKind() != CK_ArrayToPointerDecay)75 return;76 77 diag(MatchedCast->getExprLoc(), "do not implicitly decay an array into a "78 "pointer; consider using gsl::array_view or "79 "an explicit cast instead");80}81 82} // namespace clang::tidy::cppcoreguidelines83