cmake: allow embedding to depend on a target

Author: renzbagaporo

docs/en/api-guides/build-system.rst

@@ -830,6 +830,24 @@ Place this line after the ``project()`` line in your project CMakeLists.txt file
 
 For an example of using this technique, see :example:`protocols/https_request` - the certificate file contents are loaded from the text .pem file at compile time.
 
+
+.. highlight:: cmake
+
+It is also possible embed a generated file::
+
+  add_custom_command(OUTPUT my_processed_file.bin
+                    COMMAND my_process_file_cmd my_unprocessed_file.bin)
+  target_add_binary_data(my_target "my_processed_file.bin" BINARY)
+
+In the example above, ``my_processed_file.bin`` is generated from ``my_unprocessed_file.bin`` through some command ``my_process_file_cmd``, then embedded into the target.
+
+To specify a dependence on a target, use the ``DEPENDS`` argument::
+
+  add_custom_target(my_process COMMAND ...)
+  target_add_binary_data(my_target "my_embed_file.bin" BINARY DEPENDS my_process)
+
+The ``DEPENDS`` argument to ``target_add_binary_data`` ensures that the target executes first.
+
 Code and Data Placements
 ------------------------
 

tools/cmake/utilities.cmake

@@ -77,7 +77,7 @@ endfunction()
 # by converting it to a generated source file which is then compiled
 # to a binary object as part of the build
 function(target_add_binary_data target embed_file embed_type)
-    cmake_parse_arguments(_ "" "RENAME_TO" "" ${ARGN})
+    cmake_parse_arguments(_ "" "RENAME_TO" "DEPENDS" ${ARGN})
     idf_build_get_property(build_dir BUILD_DIR)
     idf_build_get_property(idf_path IDF_PATH)
 
@@ -99,7 +99,7 @@ function(target_add_binary_data target embed_file embed_type)
         -D "FILE_TYPE=${embed_type}"
         -P "${idf_path}/tools/cmake/scripts/data_file_embed_asm.cmake"
         MAIN_DEPENDENCY "${embed_file}"
-        DEPENDS "${idf_path}/tools/cmake/scripts/data_file_embed_asm.cmake"
+        DEPENDS "${idf_path}/tools/cmake/scripts/data_file_embed_asm.cmake" ${__DEPENDS}
         WORKING_DIRECTORY "${build_dir}"
         VERBATIM)