On 1/15/25 11:38 AM, Quentin Schulz wrote:
Hi Marek,
Hi,
On 1/12/25 11:32 PM, Marek Vasut wrote:
In case the build system builds a directory with empty Makefile, one which does not contain any obj-y entries, the build fails to link due to missing built-in.o .
This happens because of this part of scripts/Makefile.build 81 ifneq ($(strip $(obj-y) $(obj-m) $(obj-) $(subdir-m) $(lib- target)),) 82 builtin-target := $(obj)/built-in.o 83 endif which does not assign builtin-target in case obj-y is empty. The built-in target is then not built at all, and built-in.o is not generated by this part of scripts/Makefile.build 325 ifdef builtin-target 326 quiet_cmd_link_o_target = AR $@ 327 # If the list of objects to link is empty, just create an empty built-in.o ... 335 targets += $(builtin-target) 336 endif # builtin-target This is the correct behavior.
The final link however expects the built-in.o to exist in every directory included in the build, even in those where the aforementioned code skipped generation of built-in.o . Make sure the built-in.o does exist for every directory used in final link simply by doing touch on every built-in.o used for the link, which will create empty built-in.o in case any built- in.o is missing.
A possible alternative fix is the always define the builtin-target and always generate built-in.o .
Signed-off-by: Marek Vasut marek.vasut+renesas@mailbox.org
I tested this with the following diff:
[..]
which allows me to use HAVE_VENDOR_COMMON_LIB mechanism with an empty Makefile for TPL/SPL build stage, so:
Tested-by: Quentin Schulz quentin.schulz@cherry.de
Thank you
Looking forward to being able to use HAVE_VENDOR_COMMON_LIB!
Though I could actually always include the file and just ifdef CONFIG_XPL_BUILD in common.o, but let's see where this patch goes first :)
If the intent is to use an empty Makefile (with or without ifdeferry) in any directory pulled into the build, to mitigate the missing built-in.o problem, that also won't work without this patch, because empty Makefile itself won't lead to generation of the built-in.o .