3.4.2.1. License Flag Matching

-3.4.2.1. License Flag Matching

- The definition of 'matching' in reference to a - recipe's LICENSE_FLAGS setting is simple. - However, some things exist that you should know about in order to - correctly and effectively use it. -

- Before a flag - defined by a particular recipe is tested against the - contents of the LICENSE_FLAGS_WHITELIST variable, the - string _${PN} (with - PN expanded of course) is - appended to the flag, thus automatically making each - LICENSE_FLAGS value recipe-specific. - That string is - then matched against the whitelist. - So if you specify LICENSE_FLAGS = "commercial" in recipe - "foo" for example, the string "commercial_foo" - would normally be what is specified in the whitelist in order for it to - match. -

- You can broaden the match by - putting any "_"-separated beginning subset of a - LICENSE_FLAGS flag in the whitelist, which will also - match. - For example, simply specifying "commercial" in - the whitelist would match any expanded LICENSE_FLAGS - definition starting with "commercial" such as - "commercial_foo" and "commercial_bar", which are the - strings that would be automatically generated for - hypothetical "foo" and "bar" recipes assuming those - recipes had simply specified the following: -

-     LICENSE_FLAGS = "commercial"
-

- Broadening the match allows for a range of specificity for the items - in the whitelist, from more general to perfectly - specific. - So you have the choice of exhaustively - enumerating each license flag in the whitelist to - allow only those specific recipes into the image, or - of using a more general string to pick up anything - matching just the first component or components of the specified - string. -

- This scheme works even if the flag already - has _${PN} appended - the extra _${PN} is - redundant, but does not affect the outcome. - For example, a license flag of "commercial_1.2_foo" would - turn into "commercial_1.2_foo_foo" and would match - both the general "commercial" and the specific - "commercial_1.2_foo", as expected. - The flag would also match - "commercial_1.2_foo_foo" and "commercial_1.2", which - does not make much sense regarding use in the whitelist. -

- For a versioned string, you could instead specify - "commercial_foo_1.2", which would turn into - "commercial_foo_1.2_foo". - And, as expected, this flag allows - you to pick up this package along with - anything else "commercial" when you specify "commercial" - in the whitelist. - Or, the flag allows you to pick up this package along with anything "commercial_foo" - regardless of version when you use "commercial_foo" in the whitelist. - Finally, you can be completely specific about the package and version and specify - "commercial_foo_1.2" package and version. -