Congcong Cai b7914dffd6
[clang-tidy] add default error message for performance-avoid-endl (#107867)
use std::endl as default message when matched expr does not have valid
source text

Fixes: #107859
2024-09-14 07:33:06 +08:00

88 lines
3.5 KiB
C++

//===--- AvoidEndlCheck.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 "AvoidEndlCheck.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/DeclCXX.h"
#include "clang/AST/Expr.h"
#include "clang/AST/ExprCXX.h"
#include "clang/ASTMatchers/ASTMatchFinder.h"
#include "clang/ASTMatchers/ASTMatchers.h"
#include "clang/Lex/Lexer.h"
using namespace clang::ast_matchers;
namespace clang::tidy::performance {
void AvoidEndlCheck::registerMatchers(MatchFinder *Finder) {
Finder->addMatcher(
callExpr(
unless(isExpansionInSystemHeader()),
anyOf(cxxOperatorCallExpr(
hasOverloadedOperatorName("<<"),
hasRHS(declRefExpr(to(namedDecl(hasName("::std::endl"))))
.bind("expr"))),
callExpr(argumentCountIs(1),
callee(functionDecl(hasName("::std::endl"))))
.bind("expr"))),
this);
}
void AvoidEndlCheck::check(const MatchFinder::MatchResult &Result) {
const auto *Expression = Result.Nodes.getNodeAs<Expr>("expr");
assert(Expression);
assert(isa<DeclRefExpr>(Expression) || isa<CallExpr>(Expression));
// FIXME: It would be great if we could transform
// 'std::cout << "Hi" << std::endl;' into
// 'std::cout << "Hi\n"';
if (llvm::isa<DeclRefExpr>(Expression)) {
// Handle the more common streaming '... << std::endl' case
const CharSourceRange TokenRange =
CharSourceRange::getTokenRange(Expression->getSourceRange());
StringRef SourceText = Lexer::getSourceText(
TokenRange, *Result.SourceManager, Result.Context->getLangOpts());
if (SourceText.empty())
SourceText = "std::endl";
auto Diag = diag(Expression->getBeginLoc(),
"do not use '%0' with streams; use '\\n' instead")
<< SourceText;
if (TokenRange.isValid())
Diag << FixItHint::CreateReplacement(TokenRange, "'\\n'");
} else {
// Handle the less common function call 'std::endl(...)' case
const auto *CallExpression = llvm::cast<CallExpr>(Expression);
assert(CallExpression->getNumArgs() == 1);
StringRef SourceText = Lexer::getSourceText(
CharSourceRange::getTokenRange(
CallExpression->getCallee()->getSourceRange()),
*Result.SourceManager, Result.Context->getLangOpts());
if (SourceText.empty())
SourceText = "std::endl";
auto Diag = diag(CallExpression->getBeginLoc(),
"do not use '%0' with streams; use '\\n' instead")
<< SourceText;
const CharSourceRange ArgTokenRange = CharSourceRange::getTokenRange(
CallExpression->getArg(0)->getSourceRange());
const StringRef ArgSourceText = Lexer::getSourceText(
ArgTokenRange, *Result.SourceManager, Result.Context->getLangOpts());
const CharSourceRange ReplacementRange =
CharSourceRange::getTokenRange(CallExpression->getSourceRange());
if (!ArgSourceText.empty() && ReplacementRange.isValid()) {
const std::string ReplacementString =
std::string(ArgSourceText) + " << '\\n'";
Diag << FixItHint::CreateReplacement(ReplacementRange, ReplacementString);
}
}
}
} // namespace clang::tidy::performance