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
9#include "StaticAccessedThroughInstanceCheck.h"
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
16namespace clang::tidy::readability {
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
37void StaticAccessedThroughInstanceCheck::storeOptions(
38 ClangTidyOptions::OptionMap &Opts) {
39 Options.store(Options&: Opts, LocalName: "NameSpecifierNestingThreshold",
40 Value: NameSpecifierNestingThreshold);
41}
42
43void StaticAccessedThroughInstanceCheck::registerMatchers(MatchFinder *Finder) {
44 Finder->addMatcher(
45 NodeMatch: memberExpr(hasDeclaration(InnerMatcher: anyOf(cxxMethodDecl(isStatic()),
46 varDecl(hasStaticStorageDuration()),
47 enumConstantDecl())))
48 .bind(ID: "memberExpression"),
49 Action: this);
50}
51
52void StaticAccessedThroughInstanceCheck::check(
53 const MatchFinder::MatchResult &Result) {
54 const auto *MemberExpression =
55 Result.Nodes.getNodeAs<MemberExpr>(ID: "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.PrintAsCanonical =
73 !BaseExpr->getType()->isTypedefNameType();
74
75 std::string BaseTypeName =
76 BaseType.getAsString(Policy: 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(Prefix: "__cuda_builtin_"))
85 return;
86
87 SourceLocation MemberExprStartLoc = MemberExpression->getBeginLoc();
88 auto CreateFix = [&] {
89 return FixItHint::CreateReplacement(
90 RemoveRange: CharSourceRange::getCharRange(B: MemberExprStartLoc,
91 E: MemberExpression->getMemberLoc()),
92 Code: BaseTypeName + "::");
93 };
94
95 {
96 auto Diag =
97 diag(Loc: MemberExprStartLoc, Description: "static member accessed through instance");
98
99 if (getNameSpecifierNestingLevel(QType: BaseType) > NameSpecifierNestingThreshold)
100 return;
101
102 if (!BaseExpr->HasSideEffects(Ctx: *AstContext,
103 /* IncludePossibleEffects =*/true)) {
104 Diag << CreateFix();
105 return;
106 }
107 }
108
109 diag(Loc: MemberExprStartLoc, Description: "member base expression may carry some side effects",
110 Level: DiagnosticIDs::Level::Note)
111 << BaseExpr->getSourceRange() << CreateFix();
112}
113
114} // namespace clang::tidy::readability
115

source code of clang-tools-extra/clang-tidy/readability/StaticAccessedThroughInstanceCheck.cpp