Build files that suppress -Wnoexcept on their own

unit-udt.cpp suppresses GCC's -Wnoexcept around its include of the
library just like unit-noexcept.cpp, so instead of listing the files,
leave every file that suppresses the warning out of the batches.

Move the helpers of unit-comparison.cpp into an anonymous namespace
inside unit_comparison_detail, as clang-tidy's misc-use-internal-linkage
wants internal linkage for them.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

cmake/test.cmake

@@ -416,11 +416,9 @@ function(json_test_add_unity_tests)
     endforeach()
 
     # files that must not be merged into a batch: unit-32bit.cpp is only built
-    # for 32bit targets, unit-no-macro-leak.cpp checks that including the
+    # for 32bit targets, and unit-no-macro-leak.cpp checks that including the
-    # library defines no unprefixed macro, which any other file would disturb,
+    # library defines no unprefixed macro, which any other file would disturb
-    # and unit-noexcept.cpp suppresses GCC's -Wnoexcept around its include of
+    set(standalone_files unit-32bit.cpp unit-no-macro-leak.cpp)
-    # the library, which has no effect once another file included it first
-    set(standalone_files unit-32bit.cpp unit-no-macro-leak.cpp unit-noexcept.cpp)
 
     set(harmless_macros "^(DOCTEST_.*|SKIP_TESTS_FOR_.*|JSON_TEST_DEPRECATED_FUNCTIONS_DELETED|JSON_TEST_STRICT_NUL_HANDLING_ENABLED|JSON_TEST_STRINGIZE)$")
 
@@ -446,6 +444,17 @@ function(json_test_add_unity_tests)
             endif()
         endforeach()
 
+        # files that suppress GCC's -Wnoexcept around their include of the
+        # library: the suppression has no effect once another file of the
+        # batch included the library first
+        if(batchable)
+            file(READ ${file} file_content)
+            string(FIND "${file_content}" "SUPPRESS_WARNING(\"-Wnoexcept\")" suppresses_noexcept)
+            if(NOT ${suppresses_noexcept} EQUAL -1)
+                set(batchable FALSE)
+            endif()
+        endif()
+
         set(pool plain)
         if(batchable)
             # collect the macros (un)defined before the library is included

tests/src/unit-comparison.cpp

@@ -544,6 +544,8 @@ TEST_CASE("lexicographical comparison operators")
 
 namespace unit_comparison_detail
 {
+namespace
+{
 // orders keys ascending or descending, as chosen when a map is created
 template<class Key>
 class directed_less
@@ -595,7 +597,7 @@ struct unordered_object_t : std::map<Key, Value, directed_less<Key>, Allocator>
 using unordered_json = nlohmann::json::with_object_t<unordered_object_t>;
 
 // the entries "0" to "9", enumerated in ascending or in descending order
-inline unordered_json make_unordered_object(const bool descending)
+unordered_json make_unordered_object(const bool descending)
 {
     unordered_json j = unordered_json::object_t(directed_less<std::string>(descending));
     for (int i = 0; i < 10; ++i)
@@ -674,6 +676,7 @@ struct case_insensitive_less
 template<class Key, class Value, class /*Compare*/, class Allocator>
 using case_insensitive_map = std::map<Key, Value, case_insensitive_less, Allocator>;
 using ci_json = nlohmann::json::with_object_t<case_insensitive_map>;
+} // namespace
 } // namespace unit_comparison_detail
 
 // using-declarations rather than a using-directive, as this file may be