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//===--- UndelegatedConstructorCheck.cpp - clang-tidy --------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "UndelegatedConstructorCheck.h"
#include "clang/AST/ASTContext.h"
#include "clang/Lex/Lexer.h"
using namespace clang::ast_matchers;
namespace clang {
namespace tidy {
namespace bugprone {
namespace {
AST_MATCHER_P(Stmt, ignoringTemporaryExpr,
ast_matchers::internal::Matcher<Stmt>, InnerMatcher) {
const Stmt *E = &Node;
for (;;) {
// Temporaries with non-trivial dtors.
if (const auto *EWC = dyn_cast<ExprWithCleanups>(E))
E = EWC->getSubExpr();
// Temporaries with zero or more than two ctor arguments.
else if (const auto *BTE = dyn_cast<CXXBindTemporaryExpr>(E))
E = BTE->getSubExpr();
// Temporaries with exactly one ctor argument.
else if (const auto *FCE = dyn_cast<CXXFunctionalCastExpr>(E))
E = FCE->getSubExpr();
else
break;
}
return InnerMatcher.matches(*E, Finder, Builder);
}
// Finds a node if it's a base of an already bound node.
AST_MATCHER_P(CXXRecordDecl, baseOfBoundNode, std::string, ID) {
return Builder->removeBindings(
[&](const ast_matchers::internal::BoundNodesMap &Nodes) {
const auto *Derived = Nodes.getNodeAs<CXXRecordDecl>(ID);
return Derived != &Node && !Derived->isDerivedFrom(&Node);
});
}
} // namespace
void UndelegatedConstructorCheck::registerMatchers(MatchFinder *Finder) {
// We look for calls to constructors of the same type in constructors. To do
// this we have to look through a variety of nodes that occur in the path,
// depending on the type's destructor and the number of arguments on the
// constructor call, this is handled by ignoringTemporaryExpr. Ignore template
// instantiations to reduce the number of duplicated warnings.
Finder->addMatcher(
traverse(
TK_AsIs,
compoundStmt(hasParent(cxxConstructorDecl(
ofClass(cxxRecordDecl().bind("parent")))),
forEach(ignoringTemporaryExpr(
cxxConstructExpr(
hasDeclaration(cxxConstructorDecl(ofClass(
cxxRecordDecl(baseOfBoundNode("parent"))))))
.bind("construct"))),
unless(isInTemplateInstantiation()))),
this);
}
void UndelegatedConstructorCheck::check(
const MatchFinder::MatchResult &Result) {
const auto *E = Result.Nodes.getNodeAs<CXXConstructExpr>("construct");
diag(E->getBeginLoc(), "did you intend to call a delegated constructor? "
"A temporary object is created here instead");
}
} // namespace bugprone
} // namespace tidy
} // namespace clang
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