[clang-tidy] add default error message for performance-avoid-endl

[HerrCai0907]

use ::std::endl as default message when matched expr does not have valid source text

Fixes: #107859

[llvmbot]

@llvm/pr-subscribers-clang-tools-extra

@llvm/pr-subscribers-clang-tidy

Author: Congcong Cai (HerrCai0907)

Changes

use ::std::endl as default message when matched expr does not have valid source text

---

Full diff: https://github.com/llvm/llvm-project/pull/107867.diff

3 Files Affected:

• (modified) clang-tools-extra/clang-tidy/performance/AvoidEndlCheck.cpp (+6-7)
• (modified) clang-tools-extra/docs/ReleaseNotes.rst (+4)
• (modified) clang-tools-extra/test/clang-tidy/checkers/performance/avoid-endl.cpp (+11)

diff --git a/clang-tools-extra/clang-tidy/performance/AvoidEndlCheck.cpp b/clang-tools-extra/clang-tidy/performance/AvoidEndlCheck.cpp
index 8ecaa41754fb2b..4cfe1ca49f317c 100644
--- a/clang-tools-extra/clang-tidy/performance/AvoidEndlCheck.cpp
+++ b/clang-tools-extra/clang-tidy/performance/AvoidEndlCheck.cpp
@@ -46,14 +46,13 @@ void AvoidEndlCheck::check(const MatchFinder::MatchResult &Result) {
     // Handle the more common streaming '... << std::endl' case
     const CharSourceRange TokenRange =
         CharSourceRange::getTokenRange(Expression->getSourceRange());
-    const StringRef SourceText = Lexer::getSourceText(
+    StringRef SourceText = Lexer::getSourceText(
         TokenRange, *Result.SourceManager, Result.Context->getLangOpts());
-
-    auto Diag = diag(Expression->getBeginLoc(),
-                     "do not use '%0' with streams; use '\\n' instead")
-                << SourceText;
-
-    Diag << FixItHint::CreateReplacement(TokenRange, "'\\n'");
+    if (SourceText.empty())
+      SourceText = "::std::endl";
+    diag(Expression->getBeginLoc(),
+         "do not use '%0' with streams; use '\\n' instead")
+        << SourceText << FixItHint::CreateReplacement(TokenRange, "'\\n'");
   } else {
     // Handle the less common function call 'std::endl(...)' case
     const auto *CallExpression = llvm::cast<CallExpr>(Expression);
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index 8d028f8863cb7a..6768e243add997 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -120,6 +120,10 @@ Changes in existing checks
   <clang-tidy/checks/modernize/use-std-print>` check to support replacing
   member function calls too.
 
+- Improved :doc:`performance-avoid-endl
+  <clang-tidy/checks/performance/avoid-endl>` check by fixing incorrect
+  message.
+
 - Improved :doc:`readablility-implicit-bool-conversion
   <clang-tidy/checks/readability/implicit-bool-conversion>` check
   by adding the option `UseUpperCaseLiteralSuffix` to select the
diff --git a/clang-tools-extra/test/clang-tidy/checkers/performance/avoid-endl.cpp b/clang-tools-extra/test/clang-tidy/checkers/performance/avoid-endl.cpp
index 462b88773d231c..dd2d61a78d7965 100644
--- a/clang-tools-extra/test/clang-tidy/checkers/performance/avoid-endl.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/performance/avoid-endl.cpp
@@ -225,3 +225,14 @@ void bad_custom_stream() {
   // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: do not use 'std::endl' with streams; use '\n' instead [performance-avoid-endl]
   // CHECK-FIXES: logger << '\n';
 }
+
+namespace gh107859 {
+
+#define ENDL std::endl;
+
+void bad_macro() {
+  std::cout << ENDL;
+  // CHECK-MESSAGES: :[[@LINE-1]]:16: warning: do not use '::std::endl' with streams; use '\n' instead [performance-avoid-endl]
+}
+
+} // namespace gh107859

[5chmidti]

LGTM

[5chmidti]

Sounds better IMO

as a default when the lexer can not retrieve the source text.