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| //===--- ReturnBracedInitListCheck.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 "ReturnBracedInitListCheck.h"
#include "clang/AST/ASTContext.h"
#include "clang/ASTMatchers/ASTMatchFinder.h"
#include "clang/Lex/Lexer.h"
#include "clang/Tooling/FixIt.h"
using namespace clang::ast_matchers;
namespace clang {
namespace tidy {
namespace modernize {
void ReturnBracedInitListCheck::registerMatchers(MatchFinder *Finder) {
// Only register the matchers for C++.
if (!getLangOpts().CPlusPlus11)
return;
// Skip list initialization and constructors with an initializer list.
auto ConstructExpr =
cxxConstructExpr(
unless(anyOf(hasDeclaration(cxxConstructorDecl(isExplicit())),
isListInitialization(), hasDescendant(initListExpr()),
isInTemplateInstantiation())))
.bind("ctor");
auto CtorAsArgument = materializeTemporaryExpr(anyOf(
has(ConstructExpr), has(cxxFunctionalCastExpr(has(ConstructExpr)))));
Finder->addMatcher(
functionDecl(isDefinition(), // Declarations don't have return statements.
returns(unless(anyOf(builtinType(), autoType()))),
hasDescendant(returnStmt(hasReturnValue(
has(cxxConstructExpr(has(CtorAsArgument)))))))
.bind("fn"),
this);
}
void ReturnBracedInitListCheck::check(const MatchFinder::MatchResult &Result) {
const auto *MatchedFunctionDecl = Result.Nodes.getNodeAs<FunctionDecl>("fn");
const auto *MatchedConstructExpr =
Result.Nodes.getNodeAs<CXXConstructExpr>("ctor");
// Don't make replacements in macro.
SourceLocation Loc = MatchedConstructExpr->getExprLoc();
if (Loc.isMacroID())
return;
// Make sure that the return type matches the constructed type.
const QualType ReturnType =
MatchedFunctionDecl->getReturnType().getCanonicalType();
const QualType ConstructType =
MatchedConstructExpr->getType().getCanonicalType();
if (ReturnType != ConstructType)
return;
auto Diag = diag(Loc, "avoid repeating the return type from the "
"declaration; use a braced initializer list instead");
const SourceRange CallParensRange =
MatchedConstructExpr->getParenOrBraceRange();
// Make sure there is an explicit constructor call.
if (CallParensRange.isInvalid())
return;
// Make sure that the ctor arguments match the declaration.
for (unsigned I = 0, NumParams = MatchedConstructExpr->getNumArgs();
I < NumParams; ++I) {
if (const auto *VD = dyn_cast<VarDecl>(
MatchedConstructExpr->getConstructor()->getParamDecl(I))) {
if (MatchedConstructExpr->getArg(I)->getType().getCanonicalType() !=
VD->getType().getCanonicalType())
return;
}
}
// Range for constructor name and opening brace.
CharSourceRange CtorCallSourceRange = CharSourceRange::getTokenRange(
Loc, CallParensRange.getBegin().getLocWithOffset(-1));
Diag << FixItHint::CreateRemoval(CtorCallSourceRange)
<< FixItHint::CreateReplacement(CallParensRange.getBegin(), "{")
<< FixItHint::CreateReplacement(CallParensRange.getEnd(), "}");
}
} // namespace modernize
} // namespace tidy
} // namespace clang
|