[clang-tools-extra] Limit modernize-use-nullptr to C++11/C23 and later (PR #132816)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang-tidy

Author: None (higher-performance)

<details>
<summary>Changes</summary>

`nullptr` is not supported on earlier versions of either standard, so the tidy should not diagnose earlier uses.

---
Full diff: https://github.com/llvm/llvm-project/pull/132816.diff


1 Files Affected:

- (modified) clang-tools-extra/clang-tidy/modernize/UseNullptrCheck.cpp (+4-1) 


``````````diff
diff --git a/clang-tools-extra/clang-tidy/modernize/UseNullptrCheck.cpp b/clang-tools-extra/clang-tidy/modernize/UseNullptrCheck.cpp
index 108717e151b57..771ea3875a71a 100644
--- a/clang-tools-extra/clang-tidy/modernize/UseNullptrCheck.cpp
+++ b/clang-tools-extra/clang-tidy/modernize/UseNullptrCheck.cpp
@@ -505,7 +505,10 @@ void UseNullptrCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
 }
 
 void UseNullptrCheck::registerMatchers(MatchFinder *Finder) {
-  Finder->addMatcher(makeCastSequenceMatcher(IgnoredTypes), this);
+  // nullptr is supported starting from C++11 and C23.
+  if (getLangOpts().CPlusPlus11 || getLangOpts().C23) {
+    Finder->addMatcher(makeCastSequenceMatcher(IgnoredTypes), this);
+  }
 }
 
 void UseNullptrCheck::check(const MatchFinder::MatchResult &Result) {

``````````

</details>


https://github.com/llvm/llvm-project/pull/132816