From a7324530514e062c54277b619c76d2b4344a596b Mon Sep 17 00:00:00 2001
From: "Ryan M. Richard" <rrichard@ameslab.gov>
Date: Tue, 17 Jun 2025 10:01:19 -0500
Subject: [PATCH 1/2] uses outer project's languages for tests

---
 cmake/cmake_test/add_dir.cmake                    | 1 +
 cmake/cmake_test/templates/test_CMakeLists.txt.in | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/cmake/cmake_test/add_dir.cmake b/cmake/cmake_test/add_dir.cmake
index 064c391..53c279d 100644
--- a/cmake/cmake_test/add_dir.cmake
+++ b/cmake/cmake_test/add_dir.cmake
@@ -130,6 +130,7 @@ function(ct_add_dir _ad_test_dir)
         )
 
         # Configure the CMakeLists.txt for test in the build directory
+        cpp_enabled_languages(_CT_LANGUAGES)
         configure_file(
             "${_CT_TEMPLATES_DIR}/test_CMakeLists.txt.in"
             "${_ad_test_dest_full_path}/src/CMakeLists.txt"
diff --git a/cmake/cmake_test/templates/test_CMakeLists.txt.in b/cmake/cmake_test/templates/test_CMakeLists.txt.in
index 0c9077e..7ad01c1 100644
--- a/cmake/cmake_test/templates/test_CMakeLists.txt.in
+++ b/cmake/cmake_test/templates/test_CMakeLists.txt.in
@@ -7,7 +7,7 @@ set(_ct_min_cmake_version @_ct_min_cmake_version@) #Propagate min version down
 
 # A language is set so the dummy projects don't complain about not having a
 # linkage language.
-project(@_CT_CMAKELISTS_TEMPLATE_PROJECT_NAME@ LANGUAGES C)
+project(@_CT_CMAKELISTS_TEMPLATE_PROJECT_NAME@ LANGUAGES @_CT_LANGUAGES@)
 
 #Enable colors in Unix environments, ignored on Windows. Will not work with pipes
 set(CMAKETEST_USE_COLORS "@CMAKETEST_USE_COLORS@")

From 1262f9ebef23d4f494a41931d6b66789069f6199 Mon Sep 17 00:00:00 2001
From: "Ryan M. Richard" <rrichard@ameslab.gov>
Date: Wed, 18 Jun 2025 13:51:29 -0500
Subject: [PATCH 2/2] adds language support

---
 cmake/cmake_test/add_dir.cmake                | 55 ++++++++++++++-----
 cmake/versions.cmake                          |  2 +-
 tests/CMakeLists.txt                          |  1 +
 tests/add_dir_test/CMakeLists.txt             |  4 ++
 .../test_forward_language.cmake               |  7 +++
 .../test_no_language_set.cmake                |  7 +++
 .../set_languages/test_set_languages.cmake    |  7 +++
 7 files changed, 68 insertions(+), 15 deletions(-)
 create mode 100644 tests/add_dir_test/CMakeLists.txt
 create mode 100644 tests/add_dir_test/forward_languages/test_forward_language.cmake
 create mode 100644 tests/add_dir_test/no_language_set/test_no_language_set.cmake
 create mode 100644 tests/add_dir_test/set_languages/test_set_languages.cmake

diff --git a/cmake/cmake_test/add_dir.cmake b/cmake/cmake_test/add_dir.cmake
index 53c279d..b3513a7 100644
--- a/cmake/cmake_test/add_dir.cmake
+++ b/cmake/cmake_test/add_dir.cmake
@@ -33,31 +33,46 @@ include(cmakepp_lang/cmakepp_lang)
 # :keyword CT_DEBUG_MODE_ON: Enables debug mode when the tests are run.
 # :type CT_DEBUG_MODE_ON: bool
 # :keyword USE_REL_PATH_NAMES: Enables using shorter, relative paths for
-#                              test names, but increases the chance of name
-#                              collisions.
+#     test names, but increases the chance of name collisions.
 # :type USE_REL_PATH_NAMES: bool
 # :keyword LABEL: Use relative directory name for CTest label for all the tests
-#                 in the directory.
-#                 Run a group of labeled tests with `ctest -L <label>`
+#     in the directory. In a group of labeled tests with `ctest -L <label>`
 # :type LABEL: bool
 # :keyword LABEL_NAME: CTest label for all the tests in the directory.
-#                      Run a group of labeled tests with `ctest -L <label>`.
-#                      This argument has higher priority than LABEL
+#     Run a group of labeled tests with `ctest -L <label>`. This argument has 
+#     higher priority than LABEL
 # :type LABEL_NAME: str
-# :keyword CMAKE_OPTIONS: List of additional CMake options to be
-#                         passed to all test invocations. Options
-#                         should follow the syntax:
-#                         :code:`-D<variable_name>=<value>`
+# :keyword CMAKE_OPTIONS: List of additional CMake options to be passed to all 
+#     test invocations. Options should follow the syntax: 
+#     :code:`-D<variable_name>=<value>`
 # :type CMAKE_OPTIONS: list
+# :keyword LANGUAGES: List of coding languages to set in the 
+#    `project() <https://cmake.org/cmake/help/latest/command/project.html>` 
+#    command. The list will be forwarded to all tests in the directory. If the
+#    user does not want all tests to use the same language set, they can set
+#    this keyword to ``NONE`` and then call
+#    `enable_language() <https://cmake.org/cmake/help/latest/command/enable_language.html>`
+#    as appropriate on a test-by-test basis. For convenience, the user may set
+#    the ``LANGUAGES`` keyword to ``FORWARD_LANGUAGES`` and the tests will use
+#    the languages enabled when ``ct_add_dir`` is called. If ``LANGUAGES`` is
+#    not specified only the ``C`` language will be enabled (this is done to
+#    silence warnings about not specifying a language).
+# :type LANGUAGES: list
+#
 #]]
 function(ct_add_dir _ad_test_dir)
-    set(_ad_multi_value_args "CMAKE_OPTIONS")
+    set(_ad_multi_value_args "CMAKE_OPTIONS" "LANGUAGES")
     # TODO: This name is potentially misleading because it seems to enable
     #       debug mode for the test projects (see the use of 'ct_debug_mode'
     #       in cmake/cmake_test/templates/test_project_CMakeLists.txt.in).
-    #       I propose renaming it to something like "ENABLE_DEBUG_MODE_IN_TESTS".
+    #       I propose renaming to something like "ENABLE_DEBUG_MODE_IN_TESTS".
     set(_ad_options CT_DEBUG_MODE_ON USE_REL_PATH_NAMES LABEL)
-    cmake_parse_arguments(PARSE_ARGV 1 ADD_DIR "${_ad_options}" "LABEL_NAME" "${_ad_multi_value_args}")
+    cmake_parse_arguments(PARSE_ARGV 
+        1 
+        ADD_DIR "${_ad_options}" 
+        "LABEL_NAME" 
+        "${_ad_multi_value_args}"
+    )
 
     # This variable will be picked up by the template
     # TODO: This variable should be made Config File-specific and may end up
@@ -78,6 +93,18 @@ function(ct_add_dir _ad_test_dir)
         FOLLOW_SYMLINKS "${_ad_abs_test_dir}/*.cmake"
     )
 
+    # Determine the programming languages to hard-code into the template's
+    # project(...) command
+    if("${ADD_DIR_LANGUAGES}" STREQUAL "")
+        set(_CT_LANGUAGES "C")
+    elseif("${ADD_DIR_LANGUAGES}" STREQUAL "FORWARD_LANGUAGES")
+        cpp_enabled_languages(_CT_LANGUAGES)
+    else()
+        # Could check for parsing problems
+        set(_CT_LANGUAGES "${ADD_DIR_LANGUAGES}")
+    endif()
+
+
     # Each test file will get its own directory and "mini-project" in the
     # build directory to facilitate independently running each test case.
     # These directories are created from hashes of the test directory and
@@ -130,7 +157,7 @@ function(ct_add_dir _ad_test_dir)
         )
 
         # Configure the CMakeLists.txt for test in the build directory
-        cpp_enabled_languages(_CT_LANGUAGES)
+
         configure_file(
             "${_CT_TEMPLATES_DIR}/test_CMakeLists.txt.in"
             "${_ad_test_dest_full_path}/src/CMakeLists.txt"
diff --git a/cmake/versions.cmake b/cmake/versions.cmake
index 5f003ef..1158f00 100644
--- a/cmake/versions.cmake
+++ b/cmake/versions.cmake
@@ -14,5 +14,5 @@
 
 include_guard()
 
-set(CMAKEPP_LANG_VERSION v1.0.0)
+set(CMAKEPP_LANG_VERSION v1.1.0)
 set(CMAIZE_VERSION v0.2.1)
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 77118d7..ecf52a0 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -12,5 +12,6 @@ ct_set_print_length("${CT_DEFAULT_PRINT_LENGTH}")
 
 set(CMAKEPP_LANG_DEBUG_MODE ON)
 
+add_subdirectory("add_dir_test")
 ct_add_dir("./cmake_test" CT_DEBUG_MODE_ON)
 ct_add_dir("./test_directory_2" CT_DEBUG_MODE_ON)
diff --git a/tests/add_dir_test/CMakeLists.txt b/tests/add_dir_test/CMakeLists.txt
new file mode 100644
index 0000000..7baaafa
--- /dev/null
+++ b/tests/add_dir_test/CMakeLists.txt
@@ -0,0 +1,4 @@
+enable_language(CXX)
+ct_add_dir("./forward_languages" LANGUAGES FORWARD_LANGUAGES)
+ct_add_dir("./no_language_set")
+ct_add_dir("./set_languages" LANGUAGES C CXX)
\ No newline at end of file
diff --git a/tests/add_dir_test/forward_languages/test_forward_language.cmake b/tests/add_dir_test/forward_languages/test_forward_language.cmake
new file mode 100644
index 0000000..f5e7d0f
--- /dev/null
+++ b/tests/add_dir_test/forward_languages/test_forward_language.cmake
@@ -0,0 +1,7 @@
+ct_add_test(NAME test_forward_languages)
+function(${test_forward_languages})
+    cpp_enabled_languages(the_enabled_languages)
+
+    set(correct_value "CXX")
+    ct_assert_equal(the_enabled_languages "${correct_value}")
+endfunction()
\ No newline at end of file
diff --git a/tests/add_dir_test/no_language_set/test_no_language_set.cmake b/tests/add_dir_test/no_language_set/test_no_language_set.cmake
new file mode 100644
index 0000000..2c9732c
--- /dev/null
+++ b/tests/add_dir_test/no_language_set/test_no_language_set.cmake
@@ -0,0 +1,7 @@
+ct_add_test(NAME test_no_language_set)
+function(${test_no_language_set})
+    cpp_enabled_languages(the_enabled_languages)
+
+    set(correct_value "C")
+    ct_assert_equal(the_enabled_languages "${correct_value}")
+endfunction()
\ No newline at end of file
diff --git a/tests/add_dir_test/set_languages/test_set_languages.cmake b/tests/add_dir_test/set_languages/test_set_languages.cmake
new file mode 100644
index 0000000..79079b7
--- /dev/null
+++ b/tests/add_dir_test/set_languages/test_set_languages.cmake
@@ -0,0 +1,7 @@
+ct_add_test(NAME test_set_languages)
+function(${test_set_languages})
+    cpp_enabled_languages(the_enabled_languages)
+
+    set(correct_value "C;CXX")
+    ct_assert_equal(the_enabled_languages "${correct_value}")
+endfunction()
\ No newline at end of file