Parse included board files for pico_cmake_set declarations

Author: will-v-pi

cmake/generic_board.cmake

@@ -30,6 +30,13 @@ if (EXISTS ${PICO_BOARD_HEADER_FILE})
                 list(APPEND PICO_BOARD_CMAKE_OVERRIDES ${CMAKE_MATCH_1})
             endif()
         endif()
+        if (LINE MATCHES "^[ \t\]*#include[ \t\]*\"boards\/(.+)\"")
+            pico_find_in_paths(PICO_INCLUDED_BOARD_HEADER_FILE PICO_BOARD_HEADER_DIRS ${CMAKE_MATCH_1})
+            if (EXISTS ${PICO_INCLUDED_BOARD_HEADER_FILE})
+                file(STRINGS ${PICO_INCLUDED_BOARD_HEADER_FILE} INCLUDED_HEADER_FILE_CONTENTS)
+                list(PREPEND HEADER_FILE_CONTENTS ${INCLUDED_HEADER_FILE_CONTENTS})
+            endif()
+        endif()
     endwhile()
 else()
     set(msg "Unable to find definition of board '${PICO_BOARD}' (specified by PICO_BOARD):\n")