Re: [PATCH net-next v3 1/2] tools: ynl: Allow cross-compiling ynl and associated tools

From: Bobby Eshleman

Date: Tue Sep 08 2026 - 21:12:11 EST


On Mon, Sep 07, 2026 at 06:14:35PM +0200, Maxime Chevallier (Netdev Foundation) wrote:
> The ynl tool and libraries may be built standalone or through the
> drivers/net/hw selftest machinery. This may target a different arch, so
> we need to take the CROSS_COMPILE variable into account for LLVM and
> gcc.
>
> Let's include the tools/scripts/Makefile.include that deals with the
> CC/AR resolution.
>
> Fixup the ynltool CFLAGS handling to use +=, so that we don't override
> the ones set in Makefile.include.
>
> Makefile.include also sets the Q variable for verbose mode, so we can
> drop it from the ynltool Makefile. This will allow properly selection
> the verbosity of ynltool builds with the V=1 make flag.
>
> Reviewed-by: Matthieu Baerts (Netdev Foundation) <matttbe@xxxxxxxxxx>
> Signed-off-by: Maxime Chevallier (Netdev Foundation) <maxime.chevallier@xxxxxxxxxxx>

Hey Maxime,

It seems that this patch may break some invocations of make:

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

Best,
Bobby

> ---
> tools/net/ynl/Makefile | 1 +
> tools/net/ynl/generated/Makefile | 3 ++-
> tools/net/ynl/lib/Makefile | 3 ++-
> tools/net/ynl/tests/Makefile | 2 +-
> tools/net/ynl/ynltool/Makefile | 6 ++----
> 5 files changed, 8 insertions(+), 7 deletions(-)
>
> diff --git a/tools/net/ynl/Makefile b/tools/net/ynl/Makefile
> index 3cefe4ed96cb..838c465d65aa 100644
> --- a/tools/net/ynl/Makefile
> +++ b/tools/net/ynl/Makefile
> @@ -1,5 +1,6 @@
> # SPDX-License-Identifier: GPL-2.0
>
> +include ../../scripts/Makefile.include
> include ../../scripts/Makefile.arch
>
> INSTALL ?= install
> diff --git a/tools/net/ynl/generated/Makefile b/tools/net/ynl/generated/Makefile
> index ea4128f612d6..5a186349b5a8 100644
> --- a/tools/net/ynl/generated/Makefile
> +++ b/tools/net/ynl/generated/Makefile
> @@ -1,6 +1,7 @@
> # SPDX-License-Identifier: GPL-2.0
>
> -CC=gcc
> +include ../../../scripts/Makefile.include
> +
> CFLAGS += -std=gnu11 -O2 -W -Wall -Wextra -Wno-unused-parameter -Wshadow \
> -I../lib/ -idirafter $(UAPI_PATH)
> ifeq ("$(DEBUG)","1")
> diff --git a/tools/net/ynl/lib/Makefile b/tools/net/ynl/lib/Makefile
> index 9b98c0599600..7b3eae89982f 100644
> --- a/tools/net/ynl/lib/Makefile
> +++ b/tools/net/ynl/lib/Makefile
> @@ -1,6 +1,7 @@
> # SPDX-License-Identifier: GPL-2.0
>
> -CC=gcc
> +include ../../../scripts/Makefile.include
> +
> CFLAGS += -std=gnu11 -O2 -W -Wall -Wextra -Wno-unused-parameter -Wshadow
> ifeq ("$(DEBUG)","1")
> CFLAGS += -g -fsanitize=address -fsanitize=leak -static-libasan
> diff --git a/tools/net/ynl/tests/Makefile b/tools/net/ynl/tests/Makefile
> index 40827ca8e579..99ae7dcd6348 100644
> --- a/tools/net/ynl/tests/Makefile
> +++ b/tools/net/ynl/tests/Makefile
> @@ -2,8 +2,8 @@
> # Makefile for YNL tests
>
> include ../Makefile.deps
> +include ../../../scripts/Makefile.include
>
> -CC=gcc
> CFLAGS += -std=gnu11 -O2 -W -Wall -Wextra -Wno-unused-parameter -Wshadow \
> -I../lib/ -I../generated/ -I../../../testing/selftests/ \
> -idirafter $(UAPI_PATH)
> diff --git a/tools/net/ynl/ynltool/Makefile b/tools/net/ynl/ynltool/Makefile
> index 48b0f32050f0..b8c67cdb4fdf 100644
> --- a/tools/net/ynl/ynltool/Makefile
> +++ b/tools/net/ynl/ynltool/Makefile
> @@ -1,12 +1,12 @@
> # SPDX-License-Identifier: GPL-2.0-only
>
> include ../Makefile.deps
> +include ../../../scripts/Makefile.include
>
> INSTALL ?= install
> prefix ?= /usr
>
> -CC := gcc
> -CFLAGS := -Wall -Wextra -Werror -O2
> +CFLAGS += -Wall -Wextra -Werror -O2
> ifeq ("$(DEBUG)","1")
> CFLAGS += -g -fsanitize=address -fsanitize=leak -static-libasan
> endif
> @@ -27,8 +27,6 @@ include $(wildcard *.d)
>
> all: $(YNLTOOL)
>
> -Q = @
> -
> $(YNLTOOL): ../libynl.a $(OBJS)
> $(Q)echo -e "\tLINK $@"
> $(Q)$(CC) $(CFLAGS) -o $@ $(OBJS) ../libynl.a -lm
> --
> 2.55.0
>