Added utility function to get common root directory of sources.

The `add_arduino_library` function has been updated to use this function in order to remove the inconvenient 'library_root_dir' argument it used to accept. As such, updated all other code using this API.

Author: MrPointer

cmake/Platform/Arduino.cmake

@@ -9,12 +9,7 @@ list(APPEND CMAKE_MODULE_PATH ${CMAKE_CURRENT_LIST_DIR}/Sources)
 list(APPEND CMAKE_MODULE_PATH ${CMAKE_CURRENT_LIST_DIR}/Libraries)
 list(APPEND CMAKE_MODULE_PATH ${CMAKE_CURRENT_LIST_DIR}/Targets)
 
-include(MathUtils)
-include(ListUtils)
-include(StringUtils)
-include(PropertyUtils)
-include(PlatformLibraryUtils)
-include(CMakeArgumentsUtils)
+include(Utilities)
 
 include(BoardManager)
 include(RecipeParser)

cmake/Platform/Libraries/LibrariesFinder.cmake

@@ -48,7 +48,7 @@ function(find_arduino_library _target_name _library_name _board_id)
                 else ()
                     set(sources ${library_headers} ${library_sources})
 
-                    add_arduino_library(${_target_name} ${_board_id} ${library_path} "${sources}"
+                    add_arduino_library(${_target_name} ${_board_id} ${sources}
                             LIB_PROPS_FILE ${library_properties_file})
                 endif ()
 

cmake/Platform/Targets/ArduinoLibraryTarget.cmake

@@ -11,7 +11,7 @@ function(add_arduino_library _target_name _board_id)
     cmake_parse_arguments(parsed_args "" "LIB_PROPS_FILE" "" ${ARGN})
     parse_sources_arguments(parsed_sources "" "LIB_PROPS_FILE" "" "${ARGN}")
 
-    resolve_library_architecture(${_library_root_dir} "${_sources}" arch_resolved_sources "${ARGN}")
+    get_sources_root_directory("${parsed_sources}" library_root_dir)
 
     if (parsed_args_LIB_PROPS_FILE)
         resolve_library_architecture(${library_root_dir} "${parsed_sources}" arch_resolved_sources

cmake/Platform/Utilities/PathUtils.cmake

@@ -0,0 +1,52 @@
+#=============================================================================#
+# Finds the shallowest path among the given sources, where shallowest is the path having
+# the least nesting level, i.e. The least number of '/' separators in its' path.
+#       _sources - List of sources paths to find shallowest path from.
+#       _return_var - Name of variable in parent-scope holding the return value.
+#       Returns - Shallowest path among given sources (Lowest nesting level).
+#=============================================================================#
+function(get_shallowest_directory_structure_path _sources _return_var)
+
+    set(min_nesting_level 9999)
+
+    foreach (source ${_sources})
+
+        string(REGEX MATCHALL "/" nesting_regex_match ${source})
+
+        list(LENGTH nesting_regex_match source_nesting_level)
+
+        if (${source_nesting_level} LESS ${min_nesting_level})
+            set(min_nested_path ${source})
+            set(min_nesting_level ${source_nesting_level})
+        endif ()
+
+    endforeach ()
+
+    set(${_return_var} ${min_nested_path} PARENT_SCOPE)
+
+endfunction()
+
+#=============================================================================#
+# Gets the path of the common root directory of all given sources.
+# It is expected that indeed all sources will have the same, common root directory.
+# E.g. src/foo.h and src/utility/bar.h both have 'src' in common.
+# However, if src/foo.c is a relative path under the C:\ drive (in Windows), and src/bar.c is
+# a relative path under the D:\ drive - This is invalid and the function will misbehave.
+#       _sources - List of sources that have a common root directory which needs to be found.
+#       _return_var - Name of variable in parent-scope holding the return value.
+#       Returns - Path to the common root directory of the given list of sources.
+#=============================================================================#
+function(get_sources_root_directory _sources _return_var)
+
+    get_shallowest_directory_structure_path("${_sources}" shallowest_path)
+
+    get_filename_component(root_dir ${shallowest_path} DIRECTORY)
+
+    if ("${root_dir}" MATCHES ".+src$") # 'src' directory has been retrieved as shallowest path
+        # The actual root directory is one level above 'src'
+        get_filename_component(root_dir ${root_dir} DIRECTORY)
+    endif ()
+
+    set(${_return_var} ${root_dir} PARENT_SCOPE)
+
+endfunction()

cmake/Platform/Utilities/Utilities.cmake

@@ -0,0 +1,7 @@
+include(MathUtils)
+include(ListUtils)
+include(StringUtils)
+include(PathUtils)
+include(PropertyUtils)
+include(PlatformLibraryUtils)
+include(CMakeArgumentsUtils)

examples/3rd-party-library/CMakeLists.txt

@@ -9,8 +9,7 @@ add_arduino_executable(3rd_Party_Arduino_Library ${board_id} 3rd_party.cpp
 target_include_directories(3rd_Party_Arduino_Library PRIVATE include)
 
 # Add the "NeoPixel" library manually using the library addition API
-add_arduino_library(Adafruit_NeoPixel ${board_id} libraries/Adafruit_NeoPixel
-        libraries/Adafruit_NeoPixel/Adafruit_NeoPixel.cpp)
+add_arduino_library(Adafruit_NeoPixel ${board_id} libraries/Adafruit_NeoPixel/Adafruit_NeoPixel.cpp)
 target_include_directories(Adafruit_NeoPixel PUBLIC libraries/Adafruit_NeoPixel)
 
 # Find the "GFX" library by 'tricking' the framework to use current directory as the Sketchbook path,