361ae80a31
[YOCTO #14917] Attempting to use a dictionary in a python code snippet for variable assignment results in an error. For example attempting something such as IDX = "green" VAL = "${@{ 'green': 1, 'blue': 2 }[d.getVar('IDX')]}" produces the error expansion of VAL threw ExpansionError: Failure expanding variable VAL, expression was ${@{ 'green': 1, 'blue': 2 }[d.getVar('IDX')]} which triggered exception SyntaxError: '{' was never closed (Var <VAL>, line 1) The existing __expand_python_regexp__, "\${@.+?}", will match the first close curly bracket encountered, resulting in incomplete and un-parsable code, and thus produce the error. We can correct this by allowing a single depth of nested curly brackets in __expand_python_regexp__ by using "\${@(?:{.*?}|.)+?}", which will match up to and including the matching close curly bracket to the open, '${@', curly bracket, even if there are one or more singly nested curly brackets present. This change allows the usecase described above to function. This change can't be made on its own though. The old regex would, in an obscure way, handle the case where a python snippet contained an unexpandable variable. Since the unexpandable variable is in curly brackets it would cause incomplete/un-parsable python code and thus remain unparsed. So something like VAL = "${@d.getVar('foo') + ${unsetvar}}" would remain unparsed as the close curly bracket in "${unsetvar}" would match and terminate the snippet prematurely. This quirk resulted in the proper handling of python snippets with unexpanded variables. With the change to __expand_python_regexp__ the full snippet will match and be parsed, but to match the old/correct behavior we would not want to parse it until ${unsetvar} can be expanded. To ensure the old/correct behavior for python snippets with unexpanded variables remains in place we add a check for unexpanded variables in the python snippets before running them. This handling of unparsed variables brings two benefits. The first we now have an explicit check visible to all for unexpanded variables instead of a somewhat hidden behavior. The second is that if there are multiple python snippets the old behavior would run the code for each but a single snippet with unexpanded variables would mean all snippets would remain unparsed, meaning more and repeated processing at a later time. For example: "${@2*2},${@d.getVar('foo') ${unsetvar}}" old behavior would give: "${@2*2},${@d.getVar('foo') ${unsetvar}}" new behavior will give: "4,${@d.getVar('foo') ${unsetvar}}" The old behavior would calculate '2*2' but toss the result when the second snippet would fail to parse resulting in future recalculations (or fetching from cache), while the new behavior avoids this. (Bitbake rev: 94e49b9b9e409c29eb04603b1305d96ebe661a4b) Signed-off-by: Mark Asselstine <mark.asselstine@windriver.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Bitbake
BitBake is a generic task execution engine that allows shell and Python tasks to be run efficiently and in parallel while working within complex inter-task dependency constraints. One of BitBake's main users, OpenEmbedded, takes this core and builds embedded Linux software stacks using a task-oriented approach.
For information about Bitbake, see the OpenEmbedded website: https://www.openembedded.org/
Bitbake plain documentation can be found under the doc directory or its integrated html version at the Yocto Project website: https://docs.yoctoproject.org
Contributing
Please refer to https://www.openembedded.org/wiki/How_to_submit_a_patch_to_OpenEmbedded for guidelines on how to submit patches, just note that the latter documentation is intended for OpenEmbedded (and its core) not bitbake patches (bitbake-devel@lists.openembedded.org) but in general main guidelines apply. Once the commit(s) have been created, the way to send the patch is through git-send-email. For example, to send the last commit (HEAD) on current branch, type:
git send-email -M -1 --to bitbake-devel@lists.openembedded.org
Mailing list:
https://lists.openembedded.org/g/bitbake-devel
Source code:
https://git.openembedded.org/bitbake/
Testing:
Bitbake has a testsuite located in lib/bb/tests/ whichs aim to try and prevent regressions. You can run this with "bitbake-selftest". In particular the fetcher is well covered since it has so many corner cases. The datastore has many tests too. Testing with the testsuite is recommended before submitting patches, particularly to the fetcher and datastore. We also appreciate new test cases and may require them for more obscure issues.