1 //===--- StaticallyConstructedObjectsCheck.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 "StaticallyConstructedObjectsCheck.h"
10
11 using namespace clang::ast_matchers;
12
13 namespace clang {
14 namespace tidy {
15 namespace fuchsia {
16
17 namespace {
AST_MATCHER(Expr,isConstantInitializer)18 AST_MATCHER(Expr, isConstantInitializer) {
19 return Node.isConstantInitializer(Finder->getASTContext(), false);
20 }
21
AST_MATCHER(VarDecl,isGlobalStatic)22 AST_MATCHER(VarDecl, isGlobalStatic) {
23 return Node.getStorageDuration() == SD_Static && !Node.isLocalVarDecl();
24 }
25 } // namespace
26
registerMatchers(MatchFinder * Finder)27 void StaticallyConstructedObjectsCheck::registerMatchers(MatchFinder *Finder) {
28 // Constructing global, non-trivial objects with static storage is
29 // disallowed, unless the object is statically initialized with a constexpr
30 // constructor or has no explicit constructor.
31 Finder->addMatcher(
32 traverse(TK_AsIs,
33 varDecl(
34 // Match global, statically stored objects...
35 isGlobalStatic(),
36 // ... that have C++ constructors...
37 hasDescendant(cxxConstructExpr(unless(allOf(
38 // ... unless it is constexpr ...
39 hasDeclaration(cxxConstructorDecl(isConstexpr())),
40 // ... and is statically initialized.
41 isConstantInitializer())))))
42 .bind("decl")),
43 this);
44 }
45
check(const MatchFinder::MatchResult & Result)46 void StaticallyConstructedObjectsCheck::check(
47 const MatchFinder::MatchResult &Result) {
48 if (const auto *D = Result.Nodes.getNodeAs<VarDecl>("decl"))
49 diag(D->getBeginLoc(), "static objects are disallowed; if possible, use a "
50 "constexpr constructor instead");
51 }
52
53 } // namespace fuchsia
54 } // namespace tidy
55 } // namespace clang
56