Ensuring existance of directories before writing files into them

[SF Markus Elfring]

Hello,

Files are stored within directories. So there is a general dependency
that the directory should exist (together with an identifier) before a file
can be changed.

Prerequisites for make rules can be specified in the way that their file names
reference a specific build directory. I have got a few approaches in mind
to convert such an implicit dependency to an explicit one for the make software.

* I could check if the source file folder is different from the selected
  build directory.

* If the desired build subdirectory did not exist, I could create it 
automatically.
  There is a choice if such a directory creation should be performed by a call
  of the make function “shell” or by a command in a recipe.
  Which design variant would you prefer for this use case?

Regards,
Markus