AvoidNestedConditionalOperatorCheck.cpp

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//===--- AvoidNestedConditionalOperatorCheck.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 "AvoidNestedConditionalOperatorCheck.h"
#include "clang/ASTMatchers/ASTMatchFinder.h"
#include "clang/ASTMatchers/ASTMatchers.h"
#include "clang/Basic/DiagnosticIDs.h"
 
using namespace clang::ast_matchers;
 
namespace clang::tidy::readability {
 
void AvoidNestedConditionalOperatorCheck::registerMatchers(
    MatchFinder *Finder) {
  Finder->addMatcher(
      conditionalOperator(
          anyOf(
              hasCondition(ignoringParenCasts(
                  conditionalOperator().bind("nested-conditional-operator"))),
              hasTrueExpression(ignoringParenCasts(
                  conditionalOperator().bind("nested-conditional-operator"))),
              hasFalseExpression(ignoringParenCasts(
                  conditionalOperator().bind("nested-conditional-operator")))))
          .bind("conditional-operator"),
      this);
}
 
void AvoidNestedConditionalOperatorCheck::check(
    const MatchFinder::MatchResult &Result) {
  const auto *CO =
      Result.Nodes.getNodeAs<ConditionalOperator>("conditional-operator");
  const auto *NCO = Result.Nodes.getNodeAs<ConditionalOperator>(
      "nested-conditional-operator");
  assert(CO);
  assert(NCO);
 
  if (CO->getBeginLoc().isMacroID() || NCO->getBeginLoc().isMacroID())
    return;
 
  diag(NCO->getBeginLoc(),
       "conditional operator is used as sub-expression of parent conditional "
       "operator, refrain from using nested conditional operators");
  diag(CO->getBeginLoc(), "parent conditional operator here",
       DiagnosticIDs::Note);
}
 
} // namespace clang::tidy::readability