clang-tools 19.0.0git
ImplementationInNamespaceCheck.cpp
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1//===--- ImplementationInNamespaceCheck.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 "NamespaceConstants.h"
11#include "clang/AST/ASTContext.h"
12#include "clang/ASTMatchers/ASTMatchFinder.h"
13
14using namespace clang::ast_matchers;
15
16namespace clang::tidy::llvm_libc {
17
19 Finder->addMatcher(
20 translationUnitDecl(
21 forEach(decl(isExpansionInMainFile(), unless(linkageSpecDecl()),
22 // anonymous namespaces generate usingDirective
23 unless(usingDirectiveDecl(isImplicit())))
24 .bind("child_of_translation_unit"))),
25 this);
26}
27
29 const MatchFinder::MatchResult &Result) {
30 const auto *MatchedDecl =
31 Result.Nodes.getNodeAs<Decl>("child_of_translation_unit");
32 const auto *NS = dyn_cast<NamespaceDecl>(MatchedDecl);
33
34 // LLVM libc declarations should be inside of a non-anonymous namespace.
35 if (NS == nullptr || NS->isAnonymousNamespace()) {
36 diag(MatchedDecl->getLocation(),
37 "declaration must be enclosed within the '%0' namespace")
39 return;
40 }
41
42 // Enforce that the namespace is the result of macro expansion
43 if (Result.SourceManager->isMacroBodyExpansion(NS->getLocation()) == false) {
44 diag(NS->getLocation(), "the outermost namespace should be the '%0' macro")
46 return;
47 }
48
49 // We want the macro to have [[gnu::visibility("hidden")]] as a prefix, but
50 // visibility is just an attribute in the AST construct, so we check that
51 // instead.
52 if (NS->getVisibility() != Visibility::HiddenVisibility) {
53 diag(NS->getLocation(), "the '%0' macro should start with '%1'")
55 return;
56 }
57
58 // Lastly, make sure the namespace name actually has the __llvm_libc prefix
59 if (NS->getName().starts_with(RequiredNamespaceRefStart) == false) {
60 diag(NS->getLocation(), "the '%0' macro expansion should start with '%1'")
62 return;
63 }
64}
65
66} // namespace clang::tidy::llvm_libc
const FunctionDecl * Decl
DiagnosticBuilder diag(SourceLocation Loc, StringRef Description, DiagnosticIDs::Level Level=DiagnosticIDs::Warning)
Add a diagnostic with the check's name.
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 const llvm::StringRef RequiredNamespaceDeclStart
static const llvm::StringRef RequiredNamespaceDeclMacroName
static const llvm::StringRef RequiredNamespaceRefStart