[PATCH 2/2] kbuild: fix asm-offset generation to work with clang

From: Masahiro Yamada
Date: Fri Apr 14 2017 - 01:51:34 EST


From: Jeroen Hofstee <jeroen@xxxxxxxxxxxxx>

KBuild abuses the asm statement to write to a file and
clang chokes about these invalid asm statements. Hack it
even more by fooling this is actual valid asm code.

Signed-off-by: Jeroen Hofstee <jeroen@xxxxxxxxxxxxx>
[masahiro:
Import Jeroen's work for U-Boot:
http://patchwork.ozlabs.org/patch/375026/
Tweak sed script a little to drop garbage '#' for GCC case, like
#define NR_PAGEFLAGS 23 /* __NR_PAGEFLAGS # */ ]
Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>

---

include/linux/kbuild.h | 6 +++---
scripts/Makefile.lib | 5 +++--
2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/include/linux/kbuild.h b/include/linux/kbuild.h
index 22a7219..4e80f3a 100644
--- a/include/linux/kbuild.h
+++ b/include/linux/kbuild.h
@@ -2,14 +2,14 @@
#define __LINUX_KBUILD_H

#define DEFINE(sym, val) \
- asm volatile("\n->" #sym " %0 " #val : : "i" (val))
+ asm volatile("\n.ascii \"->" #sym " %0 " #val "\"" : : "i" (val))

-#define BLANK() asm volatile("\n->" : : )
+#define BLANK() asm volatile("\n.ascii \"->\"" : : )

#define OFFSET(sym, str, mem) \
DEFINE(sym, offsetof(struct str, mem))

#define COMMENT(x) \
- asm volatile("\n->#" x)
+ asm volatile("\n.ascii \"->#" x "\"")

#endif
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 9c20690..a050859 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -414,9 +414,10 @@ cmd_xzmisc = (cat $(filter-out FORCE,$^) | \

# Default sed regexp - multiline due to syntax constraints
define sed-offsets
- "/^->/{s:->#\(.*\):/* \1 */:; \
+ 's:^\.ascii *"\(.*\)".*:\1:; \
+ /^->/{s:->#\(.*\):/* \1 */:; \
s:^->\([^ ]*\) [\$$#]*\([^ ]*\) \(.*\):#define \1 \2 /* \3 */:; \
- s:->::; p;}"
+ s:->::; p;}'
endef

# Use filechk to avoid rebuilds when a header changes, but the resulting file
--
2.7.4