[coreboot-gerrit] Change in coreboot[master]: payloads/external/GRUB2: fix constantly rebuilding due to git checkout

[Patrick Georgi (Code Review)]

Patrick Georgi has submitted this change. ( https://review.coreboot.org/c/coreboot/+/36343 )

Change subject: payloads/external/GRUB2: fix constantly rebuilding due to git checkout
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payloads/external/GRUB2: fix constantly rebuilding due to git checkout

Multiple git checkouts cause GRUB2 to constantly rebuild even if there
were no changes to code or config. This is due to changing timestamps.

Fix this by not creating or switching branches but instead rely on
`git checkout -f` which does not touch existing unchanged files.

To be sure to not break anyones workflow checkout is skipped and a
warning gets printed if the tree/index is unclean.

Change-Id: I7cf66f63268de973a654146a0a47c3d5ca516d4d
Signed-off-by: Michael Niewöhner 
Reviewed-on: https://review.coreboot.org/c/coreboot/+/36343
Reviewed-by: Nico Huber 
Tested-by: build bot (Jenkins) 
---
M payloads/external/GRUB2/Makefile
1 file changed, 9 insertions(+), 9 deletions(-)

Approvals:
  build bot (Jenkins): Verified
  Nico Huber: Looks good to me, approved

diff --git a/payloads/external/GRUB2/Makefile b/payloads/external/GRUB2/Makefile
index b433bc0..20afdc3 100644
--- a/payloads/external/GRUB2/Makefile
+++ b/payloads/external/GRUB2/Makefile
@@ -1,4 +1,4 @@
-TAG-$(CONFIG_GRUB2_MASTER)=
+TAG-$(CONFIG_GRUB2_MASTER)=origin/HEAD
 TAG-$(CONFIG_GRUB2_REVISION)=$(CONFIG_GRUB2_REVISION_ID)
 TAG-$(CONFIG_GRUB2_STABLE)=grub-2.04
 NAME-$(CONFIG_GRUB2_MASTER)=HEAD
@@ -15,14 +15,14 @@

checkout:
    echo "    GIT        GRUB2 $(NAME-y)"
-	test -d grub2 || \
-		git clone $(project_git_repo) $(project_dir)
-	cd grub2 && \
-		git checkout master && \
-		git pull; \
-		test -n "$(TAG-y)" && \
-			git branch -f $(NAME-y) $(TAG-y) && \
-			git checkout $(NAME-y) || true
+	test -d $(project_dir) || git clone $(project_git_repo) $(project_dir)
+	git -C $(project_dir) fetch
+ifeq ("$(shell git -C $(project_dir) status --ignored=no --untracked-files=no --porcelain)",)
+	git -C $(project_dir) checkout -f $(TAG-y)
+else
+	echo "WARNING: index/tree not clean, skipping update / force checkout."
+	echo "         Checkout manually with `git -C $(project_dir) checkout -f`."
+endif

grub2/build/config.h: $(CONFIG_DEP) | checkout
    echo "    CONFIG     GRUB2 $(NAME-y)"