[openwrt/openwrt] llvm-bpf: use SOURCE_DATE_EPOCH for generated tarball

[LEDE Commits]

nbd pushed a commit to openwrt/openwrt.git, branch master:
https://git.openwrt.org/e73855b5d1f11751a286cf0029a67a55c853d804

commit e73855b5d1f11751a286cf0029a67a55c853d804
Author: Felix Fietkau <nbd at nbd.name>
AuthorDate: Fri Nov 26 11:24:39 2021 +0100

    llvm-bpf: use SOURCE_DATE_EPOCH for generated tarball
    
    Signed-off-by: Felix Fietkau <nbd at nbd.name>
---
 target/llvm-bpf/Makefile | 1 +
 1 file changed, 1 insertion(+)

diff --git a/target/llvm-bpf/Makefile b/target/llvm-bpf/Makefile
index c9ada017e6..0e8a8826e6 100644
--- a/target/llvm-bpf/Makefile
+++ b/target/llvm-bpf/Makefile
@@ -17,6 +17,7 @@ LLVM_TAR := $(BIN_DIR)/$(LLVM_BPF_PREFIX).tar.xz
 $(LLVM_TAR): $(HOST_STAMP_INSTALLED)
 	tar -C $(STAGING_DIR_HOST) \
 		-I '$(STAGING_DIR_HOST)/bin/xz -7e -T$(if $(filter 1,$(NPROC)),2,0)' \
+		$(if $(SOURCE_DATE_EPOCH),--mtime="@$(SOURCE_DATE_EPOCH)") \
 		-cf $@.tmp llvm-bpf $(LLVM_BPF_PREFIX)
 	mv $@.tmp $@