From: Masahiro Yamada Date: Mon, 16 Apr 2018 04:18:31 +0000 (+0900) Subject: kbuild: use -fmacro-prefix-map to make __FILE__ a relative path X-Git-Tag: v2018.05-rc3~27 X-Git-Url: https://git.sur5r.net/?a=commitdiff_plain;h=1eb2e71edd55e16562e3912881c449db69623352;p=u-boot kbuild: use -fmacro-prefix-map to make __FILE__ a relative path 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 Reviewed-by: Simon Glass --- diff --git a/Makefile b/Makefile index 143644c987..316944c9d0 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 # option to the assembler.