1 | //===--- PointerArithmeticOnPolymorphicObjectCheck.cpp - clang-tidy--------===// |
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-exception |
6 | // |
7 | //===----------------------------------------------------------------------===// |
8 | |
9 | #include "PointerArithmeticOnPolymorphicObjectCheck.h" |
10 | #include "clang/AST/ASTContext.h" |
11 | #include "clang/ASTMatchers/ASTMatchFinder.h" |
12 | |
13 | using namespace clang::ast_matchers; |
14 | |
15 | namespace clang::tidy::bugprone { |
16 | |
17 | namespace { |
18 | AST_MATCHER(CXXRecordDecl, isAbstract) { return Node.isAbstract(); } |
19 | AST_MATCHER(CXXRecordDecl, isPolymorphic) { return Node.isPolymorphic(); } |
20 | } // namespace |
21 | |
22 | PointerArithmeticOnPolymorphicObjectCheck:: |
23 | PointerArithmeticOnPolymorphicObjectCheck(StringRef Name, |
24 | ClangTidyContext *Context) |
25 | : ClangTidyCheck(Name, Context), |
26 | IgnoreInheritedVirtualFunctions( |
27 | Options.get(LocalName: "IgnoreInheritedVirtualFunctions" , Default: false)) {} |
28 | |
29 | void PointerArithmeticOnPolymorphicObjectCheck::storeOptions( |
30 | ClangTidyOptions::OptionMap &Opts) { |
31 | Options.store(Options&: Opts, LocalName: "IgnoreInheritedVirtualFunctions" , |
32 | Value: IgnoreInheritedVirtualFunctions); |
33 | } |
34 | |
35 | void PointerArithmeticOnPolymorphicObjectCheck::registerMatchers( |
36 | MatchFinder *Finder) { |
37 | const auto PolymorphicPointerExpr = |
38 | expr(hasType(InnerMatcher: hasCanonicalType(InnerMatcher: pointerType(pointee(hasCanonicalType( |
39 | InnerMatcher: hasDeclaration(InnerMatcher: cxxRecordDecl(unless(isFinal()), isPolymorphic()) |
40 | .bind(ID: "pointee" )))))))) |
41 | .bind(ID: "pointer" ); |
42 | |
43 | const auto PointerExprWithVirtualMethod = |
44 | expr(hasType(InnerMatcher: hasCanonicalType( |
45 | InnerMatcher: pointerType(pointee(hasCanonicalType(InnerMatcher: hasDeclaration( |
46 | InnerMatcher: cxxRecordDecl( |
47 | unless(isFinal()), |
48 | anyOf(hasMethod(InnerMatcher: isVirtualAsWritten()), isAbstract())) |
49 | .bind(ID: "pointee" )))))))) |
50 | .bind(ID: "pointer" ); |
51 | |
52 | const auto SelectedPointerExpr = IgnoreInheritedVirtualFunctions |
53 | ? PointerExprWithVirtualMethod |
54 | : PolymorphicPointerExpr; |
55 | |
56 | const auto ArraySubscript = arraySubscriptExpr(hasBase(InnerMatcher: SelectedPointerExpr)); |
57 | |
58 | const auto BinaryOperators = |
59 | binaryOperator(hasAnyOperatorName("+" , "-" , "+=" , "-=" ), |
60 | hasEitherOperand(InnerMatcher: SelectedPointerExpr)); |
61 | |
62 | const auto UnaryOperators = unaryOperator( |
63 | hasAnyOperatorName("++" , "--" ), hasUnaryOperand(InnerMatcher: SelectedPointerExpr)); |
64 | |
65 | Finder->addMatcher(NodeMatch: ArraySubscript, Action: this); |
66 | Finder->addMatcher(NodeMatch: BinaryOperators, Action: this); |
67 | Finder->addMatcher(NodeMatch: UnaryOperators, Action: this); |
68 | } |
69 | |
70 | void PointerArithmeticOnPolymorphicObjectCheck::check( |
71 | const MatchFinder::MatchResult &Result) { |
72 | const auto *PointerExpr = Result.Nodes.getNodeAs<Expr>(ID: "pointer" ); |
73 | const auto *PointeeDecl = Result.Nodes.getNodeAs<CXXRecordDecl>(ID: "pointee" ); |
74 | |
75 | diag(PointerExpr->getBeginLoc(), |
76 | "pointer arithmetic on polymorphic object of type %0 can result in " |
77 | "undefined behavior if the dynamic type differs from the pointer type" ) |
78 | << PointeeDecl << PointerExpr->getSourceRange(); |
79 | } |
80 | |
81 | } // namespace clang::tidy::bugprone |
82 | |