When KCONFIG_KEEPALLBACKUPS is set in the environment,
instead of renaming the old .config to .config.old, kconfig puts it in
a folder named .config.backupdir that stores all backups
with the name .config.oldX where X is a number.
The latest backup is the one with the highest number.
This is useful to avoid doing a lot of manual backups to make sure to have
a working build when you make a lot of changes that can break everything.
Signed-off-by: Maxime Chretien <maxime.chretien@xxxxxxxxxxx>
---
Documentation/kbuild/kconfig.rst | 6 ++++++
Makefile | 2 +-
scripts/kconfig/confdata.c | 15 ++++++++++++++-
3 files changed, 21 insertions(+), 2 deletions(-)
diff --git a/Documentation/kbuild/kconfig.rst b/Documentation/kbuild/kconfig.rst
index dce6801d66c9..0f1dac4f1fc2 100644
--- a/Documentation/kbuild/kconfig.rst
+++ b/Documentation/kbuild/kconfig.rst
@@ -46,6 +46,12 @@ KCONFIG_OVERWRITECONFIG
If you set KCONFIG_OVERWRITECONFIG in the environment, Kconfig will not
break symlinks when .config is a symlink to somewhere else.
+KCONFIG_KEEPALLBACKUPS
+-----------------------
+If you set KCONFIG_KEEPALLBACKUPS in the environment, Kconfig will save
+all .config.old as .config.oldX where X is a number (lower is older)
+inside a folder named .config.backupdir .
+
`CONFIG_`
---------
If you set `CONFIG_` in the environment, Kconfig will prefix all symbols
diff --git a/Makefile b/Makefile
index ac2c61c37a73..c74a18c60107 100644
--- a/Makefile
+++ b/Makefile
@@ -1437,7 +1437,7 @@ CLEAN_FILES += include/ksym vmlinux.symvers \
MRPROPER_FILES += include/config include/generated \
arch/$(SRCARCH)/include/generated .tmp_objdiff \
debian snap tar-install \
- .config .config.old .version \
+ .config .config.old .config.backupdir .version \
Module.symvers \
signing_key.pem signing_key.priv signing_key.x509 \
x509.genkey extra_certificates signing_key.x509.keyid \
diff --git a/scripts/kconfig/confdata.c b/scripts/kconfig/confdata.c
index a39d93e3c6ae..a019752816a0 100644
--- a/scripts/kconfig/confdata.c
+++ b/scripts/kconfig/confdata.c
@@ -923,7 +923,20 @@ int conf_write(const char *name)
return 0;
}
- snprintf(oldname, sizeof(oldname), "%s.old", name);
+ env = getenv("KCONFIG_KEEPALLBACKUPS");
+ if (env) {
+ i = 0;
+ do {
+ snprintf(oldname, sizeof(oldname),
+ "%s.backupdir/%s.old%d", name, name, i);
+ i++;
+ } while(is_present(oldname));
+
+ if (make_parent_dir(oldname))
+ return -1;
+ } else {
+ snprintf(oldname, sizeof(oldname), "%s.old", name);
+ }
rename(name, oldname);
if (rename(tmpname, name))
return 1;
--
2.27.0
