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This implementation consists of two components:
- Type creation python modules, whose job it is to construct objects of the
defined type for a given variable in the metadata
- typecheck.bbclass, which iterates over all configuration variables with a
type defined and uses oe.types to check the validity of the values
This gives us a few benefits:
- Automatic sanity checking of all configuration variables with a defined type
- Avoid duplicating the "how do I make use of the value of this variable"
logic between its users. For variables like PATH, this is simply a split(),
for boolean variables, the duplication can result in confusing, or even
mismatched semantics (is this 0/1, empty/nonempty, what?)
- Make it easier to create a configuration UI, as the type information could
be used to provide a better interface than a text edit box (e.g checkbox for
'boolean', dropdown for 'choice')
This functionality is entirely opt-in right now. To enable the configuration
variable type checking, simply INHERIT += "typecheck". Example of a failing
type check:
BAZ = "foo"
BAZ[type] = "boolean"
$ bitbake -p
FATAL: BAZ: Invalid boolean value 'foo'
$
Examples of leveraging oe.types in a python snippet:
PACKAGES[type] = "list"
python () {
import oe.data
for pkg in oe.data.typed_value("PACKAGES", d):
bb.note("package: %s" % pkg)
}
LIBTOOL_HAS_SYSROOT = "yes"
LIBTOOL_HAS_SYSROOT[type] = "boolean"
python () {
import oe.data
assert(oe.data.typed_value("LIBTOOL_HAS_SYSROOT", d) == True)
}
Signed-off-by: Chris Larson <chris_larson@mentor.com>
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Richard Purdie
Chris Larson