Re: [PATCH net-next] tools: ynl: Fix out-of-tree build for ynltool

Hi Bobby,

On 9/10/26 19:10, Bobby Eshleman wrote:

On Wed, Sep 09, 2026 at 09:11:54AM +0200, Maxime Chevallier (Netdev Foundation) wrote:

quoted

After the blamed commit, running a out-of-tree build for ynltool fails :

  # make -C tools/net/ynl/ynltool O=/tmp/o1
  make: Entering directory 'tools/net/ynl/ynltool'
  make: *** No rule to make target '/tmp/o1/json_writer.o', needed by '/tmp/o1/ynltool'.  Stop.

ynltool's Makefile correctly accounts for $(OUTPUT) to get the list of
object files to generate :

OBJS := $(patsubst %.c,$(OUTPUT)%.o,$(SRCS))

but it never actually set $(OUTPUT) before the blamed commit, meaning
that out-of-tree buils of ynltool were always actually in-tree.

Now, the O= parameter is correctly accounted for, and the %o: %c rule fails.

Let's update the %o: %c rule to also use $(OUTPUT).

Reported-by: Bobby Eshleman <redacted>
Closes: https://lore.kernel.org/all/aqCyWQxqKDuQnZYR@devvm29614.prn0.facebook.com/ (local)
Fixes: 917f713b4ec4 ("tools: ynl: Allow cross-compiling ynl and associated tools")
Signed-off-by: Maxime Chevallier (Netdev Foundation) <maxime.chevallier@bootlin.com>

[...]

Reviewed-by: Bobby Eshleman <redacted>

Thanks :)

Nicolai noted that there's another improvement to be made, as we don't
account for modifications made to .h files. The diff would be :

-include $(wildcard *.d)
+include $(wildcard $(OUTPUT)*.d)

See [1].

May I keep your review tag if I add the above diff in v2 ?

Thanks,

Maxime

[1] : https://lore.kernel.org/all/c44d371714839566a02cd9c944c7e177@tipi-net.de/ (local)