combo-layer: exclude files

Some combined repos intentionally do not include certain files.
For example, Poky does not include bitbake's setup files and
OE-core's sample files under meta/conf.

When these files get modified in the upstream repository, applying the
patches fails and requires manual intervention. That is merely a
nuisance for someone familiar with the problem, but a real show
stopper when having the import run automatically or by someone less
experienced.

Therefore this change introduces "file_exclude", a new per-repo list
of file patterns which removes all matching files when initializing or
updating a combined repository. Because fnmatch is used under the hood
to match full path strings, removing entire directories must be done
with a pattern ending in a '/*' (in contrast to file_filter).

For Poky, the additional configuration looks like this:

[bitbake]
...
file_exclude = classes/base.bbclass
	conf/bitbake.conf
	.gitignore
	MANIFEST.in
	setup.py
	TODO

[openembedded-core]
...
file_exclude = meta/conf/bblayers.conf.sample
	meta/conf/local.conf.sample
	meta/conf/local.conf.sample.extended
	meta/conf/site.conf.sample

Signed-off-by: Patrick Ohly <patrick.ohly@intel.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>

1 files changed, 14 insertions, 0 deletions

diff --git a/scripts/combo-layer.conf.example b/scripts/combo-layer.conf.example
index 427c1b399f6..38bc53c59f2 100644
--- a/scripts/combo-layer.conf.example
+++ b/scripts/combo-layer.conf.example
@@ -42,6 +42,20 @@ last_revision =
 #   file_filter = src/*.c : only include the src *.c file
 #   file_filter = src/main.c src/Makefile.am : only include these two files
 
+# file_exclude: filter out these file(s)
+# file_exclude = [path] [path] ...
+#
+# Each entry must match a file name. In contrast do file_filter, matching
+# a directory has no effect. To achieve that, use append a * wildcard
+# at the end.
+#
+# Wildcards are applied to the complete path and also match slashes.
+#
+# example:
+#   file_exclude = src/foobar/*  : exclude everything under src/foobar
+#   file_exclude = src/main.c : filter out main.c after including it with file_filter = src/*.c
+#   file_exclude = *~ : exclude backup files
+
 # hook: if provided, the tool will call the hook to process the generated
 #     patch from upstream, and then apply the modified patch to the combo
 #     repo.