On Sat, Aug 14, 2021 at 6:15 PM Nathan Chancellor [off-list ref] wrote:

On 8/14/2021 4:41 PM, Masahiro Yamada wrote:

quoted

When CONFIG_TRIM_UNUSED_KSYMS is enabled, I see some warnings like this:

   nm: arch/x86/entry/vdso/vdso32/note.o: no symbols

$NM (both GNU nm and llvm-nm) warns when no symbol is found in the
object. Suppress the stderr.

Fixes: bbda5ec671d3 ("kbuild: simplify dependency generation for CONFIG_TRIM_UNUSED_KSYMS")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

LGTM.

FWIW binutils>=2.37 `nm -q` can be used to suppress "no symbols"
https://sourceware.org/bugzilla/show_bug.cgi?id=27408

llvm-nm>=13.0.0 supports -q as well.

Reviewed-by: Nathan Chancellor <nathan@kernel.org>

quoted

---

  scripts/gen_ksymdeps.sh | 5 ++++-
  1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/scripts/gen_ksymdeps.sh b/scripts/gen_ksymdeps.sh
index 1324986e1362..5493124e8ee6 100755
--- a/scripts/gen_ksymdeps.sh
+++ b/scripts/gen_ksymdeps.sh

@@ -4,7 +4,10 @@
  set -e

  # List of exported symbols
-ksyms=$($NM $1 | sed -n 's/.*__ksym_marker_\(.*\)/\1/p' | tr A-Z a-z)
+#
+# If the object has no symbol, $NM warns 'no symbols'.
+# Suppress the stdout.
+ksyms=$($NM $1 2>/dev/null | sed -n 's/.*__ksym_marker_\(.*\)/\1/p' | tr A-Z a-z)

  if [ -z "$ksyms" ]; then
      exit 0

--
You received this message because you are subscribed to the Google Groups "Clang Built Linux" group.
To unsubscribe from this group and stop receiving emails from it, send an email to clang-built-linux+unsubscribe@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/clang-built-linux/3afe5054-8129-fe42-b5a4-00bd091b1a0c%40kernel.org.

-- 
宋方睿