clang-tools 20.0.0git
PointerArithmeticOnPolymorphicObjectCheck.cpp
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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
10#include "clang/AST/ASTContext.h"
11#include "clang/ASTMatchers/ASTMatchFinder.h"
12
13using namespace clang::ast_matchers;
14
15namespace clang::tidy::bugprone {
16
17namespace {
18AST_MATCHER(CXXRecordDecl, isAbstract) { return Node.isAbstract(); }
19AST_MATCHER(CXXRecordDecl, isPolymorphic) { return Node.isPolymorphic(); }
20} // namespace
21
24 ClangTidyContext *Context)
25 : ClangTidyCheck(Name, Context),
26 IgnoreInheritedVirtualFunctions(
27 Options.get("IgnoreInheritedVirtualFunctions", false)) {}
28
31 Options.store(Opts, "IgnoreInheritedVirtualFunctions",
32 IgnoreInheritedVirtualFunctions);
33}
34
36 MatchFinder *Finder) {
37 const auto PolymorphicPointerExpr =
38 expr(hasType(hasCanonicalType(pointerType(pointee(hasCanonicalType(
39 hasDeclaration(cxxRecordDecl(unless(isFinal()), isPolymorphic())
40 .bind("pointee"))))))))
41 .bind("pointer");
42
43 const auto PointerExprWithVirtualMethod =
44 expr(hasType(hasCanonicalType(
45 pointerType(pointee(hasCanonicalType(hasDeclaration(
46 cxxRecordDecl(
47 unless(isFinal()),
48 anyOf(hasMethod(isVirtualAsWritten()), isAbstract()))
49 .bind("pointee"))))))))
50 .bind("pointer");
51
52 const auto SelectedPointerExpr = IgnoreInheritedVirtualFunctions
53 ? PointerExprWithVirtualMethod
54 : PolymorphicPointerExpr;
55
56 const auto ArraySubscript = arraySubscriptExpr(hasBase(SelectedPointerExpr));
57
58 const auto BinaryOperators =
59 binaryOperator(hasAnyOperatorName("+", "-", "+=", "-="),
60 hasEitherOperand(SelectedPointerExpr));
61
62 const auto UnaryOperators = unaryOperator(
63 hasAnyOperatorName("++", "--"), hasUnaryOperand(SelectedPointerExpr));
64
65 Finder->addMatcher(ArraySubscript, this);
66 Finder->addMatcher(BinaryOperators, this);
67 Finder->addMatcher(UnaryOperators, this);
68}
69
71 const MatchFinder::MatchResult &Result) {
72 const auto *PointerExpr = Result.Nodes.getNodeAs<Expr>("pointer");
73 const auto *PointeeDecl = Result.Nodes.getNodeAs<CXXRecordDecl>("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
llvm::SmallString< 256U > Name
::clang::DynTypedNode Node
void store(ClangTidyOptions::OptionMap &Options, StringRef LocalName, StringRef Value) const
Stores an option with the check-local name LocalName with string value Value to Options.
Base class for all clang-tidy checks.
DiagnosticBuilder diag(SourceLocation Loc, StringRef Description, DiagnosticIDs::Level Level=DiagnosticIDs::Warning)
Add a diagnostic with the check's name.
Every ClangTidyCheck reports errors through a DiagnosticsEngine provided by this context.
void check(const ast_matchers::MatchFinder::MatchResult &Result) override
ClangTidyChecks that register ASTMatchers should do the actual work in here.
void storeOptions(ClangTidyOptions::OptionMap &Opts) override
Should store all options supported by this check with their current values or default values for opti...
void registerMatchers(ast_matchers::MatchFinder *Finder) override
Override this to register AST matchers with Finder.
AST_MATCHER(clang::VarDecl, hasConstantDeclaration)
llvm::StringMap< ClangTidyValue > OptionMap