[clang-tools-extra] [clang-tidy] Add a new check 'modernize-use-string-view' (PR #172170)

[via cfe-commits]

================
@@ -0,0 +1,42 @@
+// RUN: %check_clang_tidy -std=c++20-or-later %s modernize-use-string-view %t -- -- -isystem %clang_tidy_headers
+
+#include <string>
+
+// ==========================================================
+// Positive tests
+// ==========================================================
+
+std::string simpleLiteral() {
+// CHECK-MESSAGES:[[@LINE-1]]:1: warning: consider using 'std::string_view' to avoid unnecessary copying and allocations [modernize-use-string-view]
+// CHECK-FIXES: std::string_view simpleLiteral() {
+  return "simpleLiteral";
+}
+
+std::wstring simpleLiteralW() {
+// CHECK-MESSAGES:[[@LINE-1]]:1: warning: consider using 'std::wstring_view' to avoid unnecessary copying and allocations [modernize-use-string-view]
+// CHECK-FIXES: std::wstring_view simpleLiteralW() {
+  return L"wide literal";
+}
+
+std::u8string simpleLiteral8() {
+// CHECK-MESSAGES:[[@LINE-1]]:1: warning: consider using 'std::u8string_view' to avoid unnecessary copying and allocations [modernize-use-string-view]
+// CHECK-FIXES: std::u8string_view simpleLiteral8() {
+  return u8"simpleLiteral";
+}
+
+std::u16string simpleLiteral16() {
+// CHECK-MESSAGES:[[@LINE-1]]:1: warning: consider using 'std::u16string_view' to avoid unnecessary copying and allocations [modernize-use-string-view]
+// CHECK-FIXES: std::u16string_view simpleLiteral16() {
+  return u"simpleLiteral";
+}
+
+std::u32string simpleLiteral32() {
+// CHECK-MESSAGES:[[@LINE-1]]:1: warning: consider using 'std::u32string_view' to avoid unnecessary copying and allocations [modernize-use-string-view]
+// CHECK-FIXES: std::u32string_view simpleLiteral32() {
+  return U"simpleLiteral";
+}
+
+// ==========================================================
+// Negative tests
+// ==========================================================
+
----------------
zeyi2 wrote:

Excessive newline? Please remove it :)

https://github.com/llvm/llvm-project/pull/172170