clang-tools 19.0.0git
StaticAccessedThroughInstanceCheck.cpp
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1//===--- StaticAccessedThroughInstanceCheck.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#include "llvm/ADT/StringRef.h"
13
14using namespace clang::ast_matchers;
15
17
18namespace {
19AST_MATCHER(CXXMethodDecl, isStatic) { return Node.isStatic(); }
20} // namespace
21
22static unsigned getNameSpecifierNestingLevel(const QualType &QType) {
23 if (const auto *ElType = QType->getAs<ElaboratedType>()) {
24 if (const NestedNameSpecifier *NestedSpecifiers = ElType->getQualifier()) {
25 unsigned NameSpecifierNestingLevel = 1;
26 do {
27 NameSpecifierNestingLevel++;
28 NestedSpecifiers = NestedSpecifiers->getPrefix();
29 } while (NestedSpecifiers);
30
31 return NameSpecifierNestingLevel;
32 }
33 }
34 return 0;
35}
36
39 Options.store(Opts, "NameSpecifierNestingThreshold",
40 NameSpecifierNestingThreshold);
41}
42
44 Finder->addMatcher(
45 memberExpr(hasDeclaration(anyOf(cxxMethodDecl(isStatic()),
46 varDecl(hasStaticStorageDuration()),
47 enumConstantDecl())))
48 .bind("memberExpression"),
49 this);
50}
51
53 const MatchFinder::MatchResult &Result) {
54 const auto *MemberExpression =
55 Result.Nodes.getNodeAs<MemberExpr>("memberExpression");
56
57 if (MemberExpression->getBeginLoc().isMacroID())
58 return;
59
60 const Expr *BaseExpr = MemberExpression->getBase();
61
62 const QualType BaseType =
63 BaseExpr->getType()->isPointerType()
64 ? BaseExpr->getType()->getPointeeType().getUnqualifiedType()
65 : BaseExpr->getType().getUnqualifiedType();
66
67 const ASTContext *AstContext = Result.Context;
68 PrintingPolicy PrintingPolicyWithSuppressedTag(AstContext->getLangOpts());
69 PrintingPolicyWithSuppressedTag.SuppressTagKeyword = true;
70 PrintingPolicyWithSuppressedTag.SuppressUnwrittenScope = true;
71
72 PrintingPolicyWithSuppressedTag.PrintCanonicalTypes =
73 !BaseExpr->getType()->isTypedefNameType();
74
75 std::string BaseTypeName =
76 BaseType.getAsString(PrintingPolicyWithSuppressedTag);
77
78 // Ignore anonymous structs/classes which will not have an identifier
79 const RecordDecl *RecDecl = BaseType->getAsCXXRecordDecl();
80 if (!RecDecl || RecDecl->getIdentifier() == nullptr)
81 return;
82
83 // Do not warn for CUDA built-in variables.
84 if (StringRef(BaseTypeName).starts_with("__cuda_builtin_"))
85 return;
86
87 SourceLocation MemberExprStartLoc = MemberExpression->getBeginLoc();
88 auto CreateFix = [&] {
89 return FixItHint::CreateReplacement(
90 CharSourceRange::getCharRange(MemberExprStartLoc,
91 MemberExpression->getMemberLoc()),
92 BaseTypeName + "::");
93 };
94
95 {
96 auto Diag =
97 diag(MemberExprStartLoc, "static member accessed through instance");
98
99 if (getNameSpecifierNestingLevel(BaseType) > NameSpecifierNestingThreshold)
100 return;
101
102 if (!BaseExpr->HasSideEffects(*AstContext,
103 /* IncludePossibleEffects =*/true)) {
104 Diag << CreateFix();
105 return;
106 }
107 }
108
109 diag(MemberExprStartLoc, "member base expression may carry some side effects",
110 DiagnosticIDs::Level::Note)
111 << BaseExpr->getSourceRange() << CreateFix();
112}
113
114} // namespace clang::tidy::readability
::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.
DiagnosticBuilder diag(SourceLocation Loc, StringRef Description, DiagnosticIDs::Level Level=DiagnosticIDs::Warning)
Add a diagnostic with the check's name.
void storeOptions(ClangTidyOptions::OptionMap &Opts) override
Should store all options supported by this check with their current values or default values for opti...
void check(const ast_matchers::MatchFinder::MatchResult &Result) override
ClangTidyChecks that register ASTMatchers should do the actual work in here.
void registerMatchers(ast_matchers::MatchFinder *Finder) override
Override this to register AST matchers with Finder.
static unsigned getNameSpecifierNestingLevel(const QualType &QType)
llvm::StringMap< ClangTidyValue > OptionMap