It should be possible for example to do this:
"$<AND:${FOO},$<BOOL:${TGT}>,$<BOOL:$<TARGET_PROPERTY:${TGT},PROP>"
such that it works simliarly to the C code:
if (foo && tgt && tgt->prop())
{
}
The example of generator expression code is a little bit contrived as
it could be written other ways with the same functionality. Nevertheless,
as these cases already work and are intentional, test for them.
Content which is incomplete as a generator expression could cause
segfaults by advancing an iterator beyond end() and dereferencing
it. Such incomplete generator expressions should be treated as
plain text instead.
The rationale is similar to that in commit b3d8f5da (GenEx: Parse comma
after colon tokens specially, 2012-10-04), in that colon tokens should
not be parsed as identifier-argument delimiters after the first colon.
Otherwise the comma is treated as plain text by ParseContent.
$<STREQUAL:,> should be valid and true.
$<STREQUAL:,something> should be valid and false.
$<STREQUAL:,,> should be non-valid as it is 3 parameters.
$<STREQUAL:something,,> should be non-valid as it is 3 parameters.
Additionally, this allows reporting the correct error for other
expressions. For example $<TARGET_PROPERTY:,> should be invalid
because it has an empty target and empty property. It shouldn't
attempt to read the property ',' on the 'implicit this' target.
Generator expressions for comparing strings, evaluating
strings as booleans, and for creating literal right-angle-brackets
and commas are added. Those may be needed in some cases
where they appear in literals.
This expression evaluates to '1' or '0' to indicate whether the build
configuration for which the expression is evaluated matches tha named
configuration. In combination with the "$<0:...>" and "$<1:...>"
expressions this allows per-configuration content to be generated.
Add generator expressions that combine and use boolean test results:
$<0:...> = empty string (ignores "...")
$<1:...> = content of "..."
$<AND:?[,?]...> = '1' if all '?' are '1', else '0'
$<OR:?[,?]...> = '0' if all '?' are '0', else '1'
$<NOT:?> = '0' if '?' is '1', else '1'
These will be useful to evaluate (future) boolean query expressions and
condition content on the results. Include tests and documentation.
Brad King
Stephen Kelly