clang-tidy module: add test for cmStrLen() check

Utilities/ClangTidyModule/Tests/CMakeLists.txt

@@ -9,3 +9,5 @@ function(add_run_clang_tidy_test check_name)
     -P "${CMAKE_CURRENT_SOURCE_DIR}/RunClangTidy.cmake"
     )
 endfunction()
+
+add_run_clang_tidy_test(cmake-use-cmstrlen)

Utilities/ClangTidyModule/Tests/cmake-use-cmstrlen-fixit.cxx

@@ -0,0 +1,37 @@
+#include <cstring>
+
+template <size_t N>
+constexpr size_t cmStrLen(const char (&/*str*/)[N])
+{
+  return N - 1;
+}
+
+namespace ns1 {
+using std::strlen;
+}
+
+namespace ns2 {
+std::size_t strlen(const char* str)
+{
+  return std::strlen(str);
+}
+}
+
+int main()
+{
+  // String variable used for calling strlen() on a variable
+  auto s0 = "howdy";
+
+  // Correction needed
+  (void)cmStrLen("Hello");
+  (void)cmStrLen("Goodbye");
+  (void)cmStrLen("Hola");
+  (void)cmStrLen("Bonjour");
+
+  // No correction needed
+  (void)ns2::strlen("Salve");
+  (void)cmStrLen("Konnichiwa");
+  (void)strlen(s0);
+
+  return 0;
+}

Utilities/ClangTidyModule/Tests/cmake-use-cmstrlen-stderr.txt

@@ -0,0 +1,2 @@
+4 warnings generated.
+clang-tidy applied 4 of 4 suggested fixes.

Utilities/ClangTidyModule/Tests/cmake-use-cmstrlen-stdout.txt

@@ -0,0 +1,20 @@
+cmake-use-cmstrlen.cxx:26:9: warning: use cmStrLen() for string literals [cmake-use-cmstrlen]
+  (void)strlen("Hello");
+        ^~~~~~
+        cmStrLen
+cmake-use-cmstrlen.cxx:26:9: note: FIX-IT applied suggested code changes
+cmake-use-cmstrlen.cxx:27:9: warning: use cmStrLen() for string literals [cmake-use-cmstrlen]
+  (void)::strlen("Goodbye");
+        ^~~~~~~~
+        cmStrLen
+cmake-use-cmstrlen.cxx:27:9: note: FIX-IT applied suggested code changes
+cmake-use-cmstrlen.cxx:28:9: warning: use cmStrLen() for string literals [cmake-use-cmstrlen]
+  (void)std::strlen("Hola");
+        ^~~~~~~~~~~
+        cmStrLen
+cmake-use-cmstrlen.cxx:28:9: note: FIX-IT applied suggested code changes
+cmake-use-cmstrlen.cxx:29:9: warning: use cmStrLen() for string literals [cmake-use-cmstrlen]
+  (void)ns1::strlen("Bonjour");
+        ^~~~~~~~~~~
+        cmStrLen
+cmake-use-cmstrlen.cxx:29:9: note: FIX-IT applied suggested code changes

Utilities/ClangTidyModule/Tests/cmake-use-cmstrlen.cxx

@@ -0,0 +1,37 @@
+#include <cstring>
+
+template <size_t N>
+constexpr size_t cmStrLen(const char (&/*str*/)[N])
+{
+  return N - 1;
+}
+
+namespace ns1 {
+using std::strlen;
+}
+
+namespace ns2 {
+std::size_t strlen(const char* str)
+{
+  return std::strlen(str);
+}
+}
+
+int main()
+{
+  // String variable used for calling strlen() on a variable
+  auto s0 = "howdy";
+
+  // Correction needed
+  (void)strlen("Hello");
+  (void)::strlen("Goodbye");
+  (void)std::strlen("Hola");
+  (void)ns1::strlen("Bonjour");
+
+  // No correction needed
+  (void)ns2::strlen("Salve");
+  (void)cmStrLen("Konnichiwa");
+  (void)strlen(s0);
+
+  return 0;
+}