diff options
| -rw-r--r-- | Config.in.legacy | 50 |
1 files changed, 43 insertions, 7 deletions
diff --git a/Config.in.legacy b/Config.in.legacy index 4f30b2b1cb..18224a0abd 100644 --- a/Config.in.legacy +++ b/Config.in.legacy @@ -1,13 +1,9 @@ # # Config.in.legacy - support for backward compatibility # -# When an existing Config.in symbol is removed, it should be added again in this -# file, and take appropriate action to approximate backward compatibility. If -# there is an equivalent (set of) new symbols, these can just be select'ed by -# the old symbol. This makes sure that running 'make oldconfig' will make things -# "just work" when upgrading to a new buildroot version. If the change is too -# fundamental and cannot be fixed by a simple select, then the old symbol should -# select BR2_LEGACY. If that symbol is set, the build will issue an error. +# When an existing Config.in symbol is removed, it should be added again in +# this file, and take appropriate action to approximate backward compatibility. +# This will make the transition for the user more convenient. # # When adding legacy symbols to this file, add them to the front. The oldest # symbols will be removed again after about two years. @@ -15,6 +11,46 @@ # The symbol should be copied as-is from the place where it was previously # defined, but the help text should be removed or replaced with something that # explains how to fix it. +# +# For bool options, the old symbol should select BR2_LEGACY, so that the user +# is informed at build-time about selected legacy options. +# If there is an equivalent (set of) new symbols, these should be select'ed by +# the old symbol for backwards compatibility. +# +# For string options, it is not possible to directly select another symbol. In +# this case, a hidden wrap bool option has to be added, that defaults to y if +# the old string is not set at its default value. The wrap symbol should select +# BR2_LEGACY. +# If the original symbol has been renamed, the new symbol should use the value +# of the old symbol as default. This requires a change outside of +# Config.in.legacy, and this should be clearly marked as such below, so that +# removal of legacy options also include the removal of these external +# references. +# +# [Example: renaming a string option from FOO to BAR] +# original symbol: +# config BR2_FOO_STRING +# string "Some foo string" +# +# becomes: +# config BR2_BAR_STRING +# string "Some bar string" +# default BR2_FOO_STRING if BR2_FOO_STRING != "" # legacy +# +# and in Config.in.legacy: +# config BR2_FOO_STRING +# string "The foo string has been renamed" +# help +# <suitable help text> +# +# config BR2_FOO_STRING_WRAP +# bool +# default y if BR2_FOO_STRING != "" +# select BR2_LEGACY +# +# # Note: BR2_FOO_STRING is still referenced from package/foo/Config.in +# +# [End of example] config BR2_LEGACY bool |
