As stated at Documentation/kbuild/llvm.rst, to make usage of ccache one
must set KBUILD_BUILD_TIMESTAMP=''. Setting this together with W=1
will trigger the following warning for every compiled file:
date: invalid date ‘+%s’
This comes from kernel-doc script, that produces the following command
when KBUILD_BUILD_TIMESTAMP is empty:
date -d"" +%s
That triggers the warning above. Add a space between the flag `-d` and
the string argument to fix date command and remove the warning.
Signed-off-by: André Almeida <andrealmeid@xxxxxxxxxx>
---
scripts/kernel-doc | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/scripts/kernel-doc b/scripts/kernel-doc
index 2791f8195203..8728f9824c65 100755
--- a/scripts/kernel-doc
+++ b/scripts/kernel-doc
@@ -160,7 +160,7 @@ my @export_file_list;
my @build_time;
if (defined($ENV{'KBUILD_BUILD_TIMESTAMP'}) &&
- (my $seconds = `date -d"${ENV{'KBUILD_BUILD_TIMESTAMP'}}" +%s`) ne '') {
+ (my $seconds = `date -d "${ENV{'KBUILD_BUILD_TIMESTAMP'}}" +%s`) ne '') {
@build_time = gmtime($seconds);
} else {
@build_time = localtime;
--
2.47.0
