The __FILE__ macro is used everywhere in U-Boot to locate the file printing the log message, such as WARN_ON(), etc. If U-Boot is built out of tree, this can be a long absolute path.
This is because Kbuild runs in the objtree instead of the srctree, then __FILE__ is expanded to a file path prefixed with $(srctree)/. A brand-new option from GCC, -fmacro-prefix-map, solves this problem. If your compiler supports it, __FILE__ is the relative path from the srctree regardless of O= option. This provides more readable log, more reproducible builds, and smaller image size. [ Linux commit: a73619a845d5625079cc1b3b820f44c899618388 ] Signed-off-by: Masahiro Yamada <yamada.masah...@socionext.com> --- GCC 8 is required to use this new option. Makefile | 3 +++ 1 file changed, 3 insertions(+) diff --git a/Makefile b/Makefile index 5cfe43f..243add1 100644 --- a/Makefile +++ b/Makefile @@ -595,6 +595,9 @@ endif KBUILD_CFLAGS += $(call cc-option,-fno-stack-protector) KBUILD_CFLAGS += $(call cc-option,-fno-delete-null-pointer-checks) +# change __FILE__ to the relative path from the srctree +KBUILD_CFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=) + KBUILD_CFLAGS += -g # $(KBUILD_AFLAGS) sets -g, which causes gcc to pass a suitable -g<format> # option to the assembler. -- 2.7.4 _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot
