@@ -1334,6 +1334,15 @@ prepare0: archprepare FORCE
# All the preparing..
prepare: prepare0
+# If possible, redefine __FILE__ as relative path from $(srctree).
+# $$ is needed to evaluate the variables in sub-directories.
+ifeq ($(call cc-option-yn,-Wno-builtin-macro-redefined),y)
+KBUILD_CFLAGS += -Wno-builtin-macro-redefined \
+ -D__FILE__=$$(call stringify,$$(src)/$$(notdir $$<))
+endif
+# CAUTION: Do not add any reference to KBUILD_CFLAGS below this line.
+# $(call cc-option,...) etc. may return wrong result.
+
# Generate some files
# ---------------------------------------------------------------------------
Since Kbuild runs in the objtree, __FILE__ can be a very long path depending of $(srctree). If objtree is a child of srctree, the situation is a bit better. ($(srctree) is "..") For other cases of out-of-tree build, filenames in WARN_ON() etc. are still an absolute path. It also means the U-Boot image depends on where it was built. Here, the idea is to redefine __FILE__ as the relative path from $(srctree), but doing so causes a compiler warning: warning: "__FILE__" redefined [-Wbuiltin-macro-redefined] The option -Wno-builtin-macro-redefined can suppress it, but it is only recognized by GCC 4.4 or newer. Redefine __FILE__ only when possible. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> --- Changes in v2: - Rephrase comments for clarification - Fix a typo Makefile | 9 +++++++++ 1 file changed, 9 insertions(+)