1//===--- AvoidEndlCheck.cpp - clang-tidy ----------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#include "AvoidEndlCheck.h"
10#include "clang/AST/ASTContext.h"
11#include "clang/AST/DeclCXX.h"
12#include "clang/AST/Expr.h"
13#include "clang/AST/ExprCXX.h"
14#include "clang/ASTMatchers/ASTMatchFinder.h"
15#include "clang/ASTMatchers/ASTMatchers.h"
16#include "clang/Lex/Lexer.h"
17
18using namespace clang::ast_matchers;
19
20namespace clang::tidy::performance {
21
22void AvoidEndlCheck::registerMatchers(MatchFinder *Finder) {
23 Finder->addMatcher(
24 NodeMatch: callExpr(
25 unless(isExpansionInSystemHeader()),
26 anyOf(cxxOperatorCallExpr(
27 hasOverloadedOperatorName(Name: "<<"),
28 hasRHS(InnerMatcher: declRefExpr(to(InnerMatcher: namedDecl(hasName(Name: "::std::endl"))))
29 .bind(ID: "expr"))),
30 callExpr(argumentCountIs(N: 1),
31 callee(InnerMatcher: functionDecl(hasName(Name: "::std::endl"))))
32 .bind(ID: "expr"))),
33 Action: this);
34}
35
36void AvoidEndlCheck::check(const MatchFinder::MatchResult &Result) {
37 const auto *Expression = Result.Nodes.getNodeAs<Expr>(ID: "expr");
38 assert(Expression);
39 assert(isa<DeclRefExpr>(Expression) || isa<CallExpr>(Expression));
40
41 // FIXME: It would be great if we could transform
42 // 'std::cout << "Hi" << std::endl;' into
43 // 'std::cout << "Hi\n"';
44
45 if (llvm::isa<DeclRefExpr>(Val: Expression)) {
46 // Handle the more common streaming '... << std::endl' case
47 const CharSourceRange TokenRange =
48 CharSourceRange::getTokenRange(Expression->getSourceRange());
49 StringRef SourceText = Lexer::getSourceText(
50 Range: TokenRange, SM: *Result.SourceManager, LangOpts: Result.Context->getLangOpts());
51 if (SourceText.empty())
52 SourceText = "std::endl";
53 auto Diag = diag(Expression->getBeginLoc(),
54 "do not use '%0' with streams; use '\\n' instead")
55 << SourceText;
56 if (TokenRange.isValid())
57 Diag << FixItHint::CreateReplacement(RemoveRange: TokenRange, Code: "'\\n'");
58 } else {
59 // Handle the less common function call 'std::endl(...)' case
60 const auto *CallExpression = llvm::cast<CallExpr>(Val: Expression);
61 assert(CallExpression->getNumArgs() == 1);
62
63 StringRef SourceText = Lexer::getSourceText(
64 Range: CharSourceRange::getTokenRange(
65 CallExpression->getCallee()->getSourceRange()),
66 SM: *Result.SourceManager, LangOpts: Result.Context->getLangOpts());
67 if (SourceText.empty())
68 SourceText = "std::endl";
69 auto Diag = diag(Loc: CallExpression->getBeginLoc(),
70 Description: "do not use '%0' with streams; use '\\n' instead")
71 << SourceText;
72
73 const CharSourceRange ArgTokenRange = CharSourceRange::getTokenRange(
74 CallExpression->getArg(Arg: 0)->getSourceRange());
75 const StringRef ArgSourceText = Lexer::getSourceText(
76 Range: ArgTokenRange, SM: *Result.SourceManager, LangOpts: Result.Context->getLangOpts());
77 const CharSourceRange ReplacementRange =
78 CharSourceRange::getTokenRange(CallExpression->getSourceRange());
79 if (!ArgSourceText.empty() && ReplacementRange.isValid()) {
80 const std::string ReplacementString =
81 std::string(ArgSourceText) + " << '\\n'";
82 Diag << FixItHint::CreateReplacement(RemoveRange: ReplacementRange, Code: ReplacementString);
83 }
84 }
85}
86
87} // namespace clang::tidy::performance
88

source code of clang-tools-extra/clang-tidy/performance/AvoidEndlCheck.cpp