add support for SOURCE_DIR argument (#97)

* add support for SOURCE_DIR argument

* simplify code

* add test

* update comment

cmake/CPM.cmake

@@ -28,7 +28,7 @@
 
 cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
 
-set(CURRENT_CPM_VERSION 0.16)
+set(CURRENT_CPM_VERSION 0.17)
 
 if(CPM_DIRECTORY)
   if(NOT ${CPM_DIRECTORY} MATCHES ${CMAKE_CURRENT_LIST_DIR})
@@ -208,22 +208,22 @@ function(CPMAddPackage)
 
   if (DEFINED CPM_ARGS_DOWNLOAD_COMMAND)
     set(FETCH_CONTENT_DECLARE_EXTRA_OPTS DOWNLOAD_COMMAND ${CPM_ARGS_DOWNLOAD_COMMAND})
-  else()
-    if (CPM_SOURCE_CACHE AND NOT DEFINED CPM_ARGS_SOURCE_DIR)
-      string(TOLOWER ${CPM_ARGS_NAME} lower_case_name)
-      set(origin_parameters ${CPM_ARGS_UNPARSED_ARGUMENTS})
-      list(SORT origin_parameters)
-      string(SHA1 origin_hash "${origin_parameters}")
-      set(download_directory ${CPM_SOURCE_CACHE}/${lower_case_name}/${origin_hash})
-      list(APPEND FETCH_CONTENT_DECLARE_EXTRA_OPTS SOURCE_DIR ${download_directory})
-      if (EXISTS ${download_directory})
-        list(APPEND FETCH_CONTENT_DECLARE_EXTRA_OPTS DOWNLOAD_COMMAND ":")
-        set(PACKAGE_INFO "${download_directory}")
-      else()
-        # remove timestamps so CMake will re-download the dependency
-        file(REMOVE_RECURSE ${CMAKE_BINARY_DIR}/_deps/${lower_case_name}-subbuild)
-        set(PACKAGE_INFO "${PACKAGE_INFO} -> ${download_directory}")
-      endif()
+  elseif(DEFINED CPM_ARGS_SOURCE_DIR)
+    set(FETCH_CONTENT_DECLARE_EXTRA_OPTS SOURCE_DIR ${CPM_ARGS_SOURCE_DIR})
+  elseif (CPM_SOURCE_CACHE)
+    string(TOLOWER ${CPM_ARGS_NAME} lower_case_name)
+    set(origin_parameters ${CPM_ARGS_UNPARSED_ARGUMENTS})
+    list(SORT origin_parameters)
+    string(SHA1 origin_hash "${origin_parameters}")
+    set(download_directory ${CPM_SOURCE_CACHE}/${lower_case_name}/${origin_hash})
+    list(APPEND FETCH_CONTENT_DECLARE_EXTRA_OPTS SOURCE_DIR ${download_directory})
+    if (EXISTS ${download_directory})
+      list(APPEND FETCH_CONTENT_DECLARE_EXTRA_OPTS DOWNLOAD_COMMAND ":")
+      set(PACKAGE_INFO "${download_directory}")
+    else()
+      # remove timestamps so CMake will re-download the dependency
+      file(REMOVE_RECURSE ${CMAKE_BINARY_DIR}/_deps/${lower_case_name}-subbuild)
+      set(PACKAGE_INFO "${PACKAGE_INFO} -> ${download_directory}")
     endif()
   endif()
 

test/unit/source_dir.cmake

@@ -0,0 +1,19 @@
+
+include(CMakePackageConfigHelpers)
+include(${CPM_PATH}/testing.cmake)
+
+set(TEST_BUILD_DIR ${CMAKE_CURRENT_BINARY_DIR}/source_dir)
+
+configure_package_config_file(
+  "${CMAKE_CURRENT_LIST_DIR}/source_dir/CMakeLists.txt.in"
+  "${CMAKE_CURRENT_LIST_DIR}/source_dir/CMakeLists.txt"
+  INSTALL_DESTINATION ${CMAKE_CURRENT_BINARY_DIR}/junk
+)
+
+execute_process(
+  COMMAND 
+  ${CMAKE_COMMAND} "-H${CMAKE_CURRENT_LIST_DIR}/source_dir" "-B${TEST_BUILD_DIR}"
+  RESULT_VARIABLE ret
+)
+
+ASSERT_EQUAL(${ret} "0")

test/unit/source_dir/.gitignore

@@ -0,0 +1 @@
+/CMakeLists.txt

test/unit/source_dir/CMakeLists.txt.in

@@ -0,0 +1,20 @@
+cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+
+project(CPMExampleCatch2)
+
+# ---- Options ----
+
+option(ENABLE_TEST_COVERAGE "Enable test coverage" OFF)
+
+# ---- Dependencies ----
+
+include(@CPM_PATH@/CPM.cmake)
+
+CPMAddPackage(
+  NAME Dependency
+  SOURCE_DIR ${CMAKE_CURRENT_LIST_DIR}/dependency
+)
+
+# ---- Call dependency method to validate correct addition of directory ----
+
+dependency_function()

test/unit/source_dir/dependency/CMakeLists.txt

@@ -0,0 +1,4 @@
+
+function(dependency_function)
+  message("called external method")
+endfunction()