kbuild: fix asm-offset generation to work with clang

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.

[masahiro:
 Import Jeroen's work for U-Boot:
 http://patchwork.ozlabs.org/patch/375026/
 Tweak sed script a little to avoid garbage '#' for GCC case, like
 #define NR_PAGEFLAGS 23 /* __NR_PAGEFLAGS       # */ ]

Signed-off-by: Jeroen Hofstee <jeroen@myspectrum.nl>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Tested-by: Matthias Kaehlcke <mka@chromium.org>

1 files changed, 6 insertions, 2 deletions

diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 8109c133887d..2209ed696fb4 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -413,10 +413,14 @@ cmd_xzmisc = (cat $(filter-out FORCE,$^) | \
 # ---------------------------------------------------------------------------
 
 # Default sed regexp - multiline due to syntax constraints
+#
+# Use [:space:] because LLVM's integrated assembler inserts <tab> around
+# the .ascii directive whereas GCC keeps the <space> as-is.
 define sed-offsets
-        "/^->/{s:->#\(.*\):/* \1 */:; \
+        's:^[[:space:]]*\.ascii[[:space:]]*"\(.*\)".*:\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