Summary:
Libc++ frequently has the need to parse more than just the builtin *test keywords* (`RUN`, `REQUIRES`, `XFAIL`, ect). For example libc++ currently needs a new keyword `MODULES-DEFINES: macro list...`. Instead of re-implementing the script parsing in libc++ this patch allows `parseIntegratedTestScript` to take custom parsers.
This patch introduces a new class `IntegratedTestKeywordParser` which implements the logic to parse/process a test keyword. Parsing of various keyword "kinds" are supported out of the box, including 'TAG', 'COMMAND', and 'LIST', which parse keywords such as `END.`, `RUN:` and `XFAIL:` respectively.
As an example after this change libc++ can implement the `MODULES-DEFINES` simply using:
```
mparser = IntegratedTestKeywordParser('MODULES-DEFINES:', ParserKind.LIST)
parseIntegratedTestScript(test, additional_parsers=[mparser])
macro_list = mparser.getValue()
```
Reviewers: ddunbar, modocache, rnk, danalbert, jroelofs
Subscribers: mgrang, llvm-commits, cfe-commits
Differential Revision: https://reviews.llvm.org/D27005
llvm-svn: 288694
df87d070c9