ci: convert to use CMake

Convert the CI to use CMake instead of Makefiles. This will allow us to
wire up support for Windows in a subsequent commit.

Author: pks-t

Diff for: .github/workflows/ci.yml

@@ -19,5 +19,7 @@ jobs:
       uses: actions/checkout@v2
     - name: Build
       run: |
-        cd test
-        make
+        mkdir build
+        cd build
+        cmake ..
+        cmake --build .

Diff for: CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.25.0)
+cmake_minimum_required(VERSION 3.16..3.29)
 
 project(clar LANGUAGES C)
 
@@ -20,6 +20,9 @@ set_target_properties(clar PROPERTIES
 	C_EXTENSIONS OFF
 )
 
-if(BUILD_TESTS)
-	add_subdirectory(test)
+if(CMAKE_PROJECT_NAME STREQUAL PROJECT_NAME)
+	include(CTest)
+	if(BUILD_TESTING)
+		add_subdirectory(test)
+	endif()
 endif()

Diff for: test/CMakeLists.txt

@@ -2,7 +2,7 @@ find_package(Python COMPONENTS Interpreter REQUIRED)
 
 add_custom_command(OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/clar.suite"
 	COMMAND "${Python_EXECUTABLE}" "${CMAKE_SOURCE_DIR}/generate.py" --output "${CMAKE_CURRENT_BINARY_DIR}"
-	DEPENDS main.c sample.c
+	DEPENDS main.c sample.c clar_test.h
 	WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}"
 )
 
@@ -15,7 +15,7 @@ set_target_properties(clar_test PROPERTIES
 
 # MSVC generates all kinds of warnings. We may want to fix these in the future
 # and then unconditionally treat warnings as errors.
-if (NOT MSVC)
+if(NOT MSVC)
 	set_target_properties(clar_test PROPERTIES
 		COMPILE_WARNING_AS_ERROR ON
 	)