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//===--- ElseAfterReturnCheck.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 "ElseAfterReturnCheck.h"
#include "clang/AST/ASTContext.h"
#include "clang/ASTMatchers/ASTMatchFinder.h"
#include "clang/Tooling/FixIt.h"
using namespace clang::ast_matchers;
namespace clang {
namespace tidy {
namespace readability {
void ElseAfterReturnCheck::registerMatchers(MatchFinder *Finder) {
const auto InterruptsControlFlow =
stmt(anyOf(returnStmt().bind("return"), continueStmt().bind("continue"),
breakStmt().bind("break"),
expr(ignoringImplicit(cxxThrowExpr().bind("throw")))));
Finder->addMatcher(
compoundStmt(forEach(
ifStmt(unless(isConstexpr()),
// FIXME: Explore alternatives for the
// `if (T x = ...) {... return; } else { <use x> }`
// pattern:
// * warn, but don't fix;
// * fix by pulling out the variable declaration out of
// the condition.
unless(hasConditionVariableStatement(anything())),
hasThen(stmt(anyOf(InterruptsControlFlow,
compoundStmt(has(InterruptsControlFlow))))),
hasElse(stmt().bind("else")))
.bind("if"))),
this);
}
void ElseAfterReturnCheck::check(const MatchFinder::MatchResult &Result) {
const auto *If = Result.Nodes.getNodeAs<IfStmt>("if");
SourceLocation ElseLoc = If->getElseLoc();
std::string ControlFlowInterruptor;
for (const auto *BindingName : {"return", "continue", "break", "throw"})
if (Result.Nodes.getNodeAs<Stmt>(BindingName))
ControlFlowInterruptor = BindingName;
DiagnosticBuilder Diag = diag(ElseLoc, "do not use 'else' after '%0'")
<< ControlFlowInterruptor;
Diag << tooling::fixit::createRemoval(ElseLoc);
// FIXME: Removing the braces isn't always safe. Do a more careful analysis.
// FIXME: Change clang-format to correctly un-indent the code.
if (const auto *CS = Result.Nodes.getNodeAs<CompoundStmt>("else"))
Diag << tooling::fixit::createRemoval(CS->getLBracLoc())
<< tooling::fixit::createRemoval(CS->getRBracLoc());
}
} // namespace readability
} // namespace tidy
} // namespace clang
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