f33319699d
Summary: This check flags all array to pointer decays. Pointers should not be used as arrays. array_view is a bounds-checked, safe alternative to using pointers to access arrays. This rule is part of the "Bounds safety" profile of the C++ Core Guidelines, see https://github.com/isocpp/CppCoreGuidelines/blob/master/CppCoreGuidelines.md#-bounds3-no-array-to-pointer-decay Reviewers: alexfh, sbenza, bkramer, aaron.ballman Subscribers: cfe-commits Differential Revision: http://reviews.llvm.org/D13640 llvm-svn: 251358
61 lines
2.1 KiB
C++
61 lines
2.1 KiB
C++
//===--- ProBoundsArrayToPointerDecayCheck.cpp - clang-tidy----------------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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#include "ProBoundsArrayToPointerDecayCheck.h"
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#include "clang/AST/ASTContext.h"
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#include "clang/ASTMatchers/ASTMatchFinder.h"
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using namespace clang::ast_matchers;
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namespace clang {
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namespace tidy {
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AST_MATCHER_P(CXXForRangeStmt, hasRangeBeginEndStmt,
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ast_matchers::internal::Matcher<DeclStmt>, InnerMatcher) {
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const DeclStmt *const Stmt = Node.getBeginEndStmt();
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return (Stmt != nullptr && InnerMatcher.matches(*Stmt, Finder, Builder));
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}
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AST_MATCHER(Stmt, isInsideOfRangeBeginEndStmt) {
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return stmt(hasAncestor(cxxForRangeStmt(
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hasRangeBeginEndStmt(hasDescendant(equalsNode(&Node))))))
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.matches(Node, Finder, Builder);
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}
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void ProBoundsArrayToPointerDecayCheck::registerMatchers(MatchFinder *Finder) {
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if (!getLangOpts().CPlusPlus)
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return;
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// The only allowed array to pointer decay
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// 1) just before array subscription
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// 2) inside a range-for over an array
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// 3) if it converts a string literal to a pointer
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Finder->addMatcher(
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implicitCastExpr(unless(hasParent(arraySubscriptExpr())),
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unless(hasParent(explicitCastExpr())),
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unless(isInsideOfRangeBeginEndStmt()),
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unless(hasSourceExpression(stringLiteral())))
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.bind("cast"),
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this);
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}
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void ProBoundsArrayToPointerDecayCheck::check(
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const MatchFinder::MatchResult &Result) {
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const auto *MatchedCast = Result.Nodes.getNodeAs<ImplicitCastExpr>("cast");
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if (MatchedCast->getCastKind() != CK_ArrayToPointerDecay)
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return;
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diag(MatchedCast->getExprLoc(), "do not implicitly decay an array into a "
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"pointer; consider using gsl::array_view or "
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"an explicit cast instead");
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}
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} // namespace tidy
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} // namespace clang
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