From: Vagrant Cascadian vagrant@reproducible-builds.org
The KBUILD_CFLAGS and KBUILD_AFLAGS variables are adjusted to use -ffile-prefix-map and --debug-prefix-map, respectively, to use relative paths for occurrences of __FILE__ and debug paths.
This enables reproducible builds regardless of the absolute path to the build directory:
https://reproducible-builds.org/docs/build-path/
Signed-off-by: Vagrant Cascadian vagrant@reproducible-builds.org
---
Makefile | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/Makefile b/Makefile index 1a66f69a4b..b40b9b2444 100644 --- a/Makefile +++ b/Makefile @@ -751,14 +751,18 @@ KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow) # Enabled with W=2, disabled by default as noisy KBUILD_CFLAGS += $(call cc-disable-warning, maybe-uninitialized)
-# change __FILE__ to the relative path from the srctree -KBUILD_CFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=) +# change __FILE__ and debugging symbols to the relative path from the +# srctree +KBUILD_CFLAGS += $(call cc-option,-ffile-prefix-map=$(srctree)/=)
KBUILD_CFLAGS += -g # $(KBUILD_AFLAGS) sets -g, which causes gcc to pass a suitable -g<format> # option to the assembler. KBUILD_AFLAGS += -g
+# Use relative paths in debugging symbols +KBUILD_AFLAGS += --debug-prefix-map=$(srctree)/= + # Report stack usage if supported # ARC tools based on GCC 7.1 has an issue with stack usage # with naked functions, see commit message for more details