[HELP] Proper multi-directory custom app integration

[stbenn]

Description

I am having issues with make recognizing file changes in my custom app. As a result, I need to make clean before every build which is not ideal.

I believe the root cause is my app having src and include directories instead of being contained in one directory like the custom app example in the NuttX documentation.

My Project Structure

I made a sample git repo that demonstrates how I have the project set up (https://github.com/stbenn/NuttxCustomAppQuestion.git) to reference in addition to the following explanation.

Directory structure:

ProjectDir/
  nuttx/
  apps/
    external/
      Make.defs
      Makefile
      custom_app/ (symlink)
  custom_app/
    /include
      header_files.h
    /src
      custom_app.c
      other_sources.c
    KConfig
    Make.defs
    Makefile

Command used to link custom app directory: in ProjectDir, ln -sr custom_app apps/external/custom_app

apps/external/Makefile

MENUDESC = "External Apps"

include $(APPDIR)/Directory.mk

apps/external/Make.defs

include $(wildcard $(APPDIR)/external/*/Make.defs)

custom_app/Make.defs

ifneq ($(CONFIG_CUSTOM_APP),)
CONFIGURED_APPS += $(APPDIR)/external/custom_app

endif

custom_app/Makefile

include $(APPDIR)/Make.defs

ifeq ($(CONFIG_CUSTOM_APP),y)

PROGNAME = $(CONFIG_CUSTOM_APP_PROGNAME)
PRIORITY = $(CONFIG_CUSTOM_APP_PRIORITY)
STACKSIZE = $(CONFIG_CUSTOM_APP_STACKSIZE)

MAINSRC = src/custom_app.c
CSRCS = src/other_sources.c

# This is how to add the include directory to the build system.
# the path to the directory should match AFTER the symlink. So here it's apps/external/custom_app/include
CFLAGS += ${shell $(INCDIR) "$(CC)" "$(APPDIR)$(DELIM)external$(DELIM)custom_app$(DELIM)include"}

endif

include $(APPDIR)/Application.mk

.PHONY: clean
clean::
	rm -f src/*.su

Note: I have also experimented with using CFLAGS += ${INCDIR_PREFIX}${APPDIR}/external/custom_app/include in custom_app/Make.defs

Desired Behavior

The NuttX build system detects when changes are made to files in the subdirectories of custom_app without requiring a make clean before make.

Verification

• I have verified before submitting the report.

[acassis]

@stbenn is this happing only with Makefile build? Or do it happen with CMake too?

@xiaoxiang781216 any idea?

[stbenn]

I have only tried the makefile build, so I can't comment on if the behavior occurs in CMake build.

[TimJTi]

I had issues with this and ended up creating a traditional makefile with the paths declared etc. I still had some issues - can't remember what to be honest - so ended up relocating my custom apps directory as a "myapps" subdirectory of the main nuttx-apps tree and it has worked well since.

Makefiles are not my strong point - by any stretch of the imagination - but I suspect that an out-of-tree custom apps folder needs to be specifically included in default NuttX makefiles/make.defs/whatever for it to play ball.

Or there's some magic incantation needed in the custom apps make.defs that makes it all work - I just don't know.

But, instead, perhaps there's a case for a new Kconfig entry in the Build Setup menus for CONFIG_CUSTOM_APPSDIR that is then included by default in the NuttX build? I can play with that and see if it works - but won't be for a couple of weeks as I'm going away for a short break.

Not related to this, but I am also looking at how to include a custom file outside of the nuttx-apps tree but used by an in-tree app. That might be easiest with a CONFIG_CUSTOM_APPINCDIR which ties in with the above and why I am happy to try this out if it's a viable solution?

[TimJTi]

Unless the "clue" is in the help text of the Kconfig setting for CONFIG_APPS_DIR ? Seems to be clues there that those who know makefiles better than me (pretty much anyone lol) can make use of?

[stbenn]

@TimJTi based on your Nuttx development environment journey explanation on your profile, you might find this interesting: https://github.com/stbenn/nuttx_docker_env

It is how I make dev environments consistent and documented in project source code. I use WSL and haven't tried a JLink yet, so your millage may vary. I anticipate it being even better when run on a native Linux machine, due to Docker preferring Linux