The test sdk that we were prebuilding to run ql tests is actually not
needed, as the `resource-dir` we package for cross-version compatibility
is enough for running qltests as well.
While I would have preferred to add a proper unit test, this required
more infrastructure for mocking system calls. Instead I made `qltest.sh`
accept a `//codeql-extractor-env` header and used that to write a QL
test exercising the `RUN_UNDER` functionality.
While the (removed) comment is correct and the frontend can be called in
different modes, both `swift build` and `xcodebuild` always use
`-primary-files` when compiling Swift projects.
The other mode was present only within our test runner (`qltest.sh`), so
removing it and doing what the official build systems do simplifies our
code base.
Additionally, file archival is now a separate function/operation.
By explicitly marking children in the `schema.yml` file, an internal
`getAChild` predicate is implemented, that is in turn used in `AstNode`
to implement `getParent`.
This is yet to be used in the control flow library to replace the
hand-rolled implementation.
A further, more complex step is to use the same information to fully
generate the core implementation of `PrintAst` (including the
accessor string). This will be done later.
The `parent` tests use the same swift code as the extractor tests, and
this is currently enforced by `sync-files.py`. Notice that `qltest.sh`
had to be modified to deal with multiple files, which was not working
yet.
Providing `--dynamic_mode=fully` (for example setting it in
`local.bazelrc`) will now work.
All runfiles are now copied in the extractor pack: in dynamic mode,
those will be the executable and the dynamic libraries, while in static
mode only the executable will be part of the runfiles.
Setting the correct `LD_LIBRARY_PATH` in `qltest.sh` then allows to
run tests with this pakcage. If we need something more, we can switch to
a wrapper script in place of `extractor` in the future.
Notice that `LD_LIBRARY_PATH` is also set in static mode, but that has
no consequence.
This adds a first dummy extractor for swift.
Running `bazel run //swift:install` will create an `extractor_pack`
directory in `swift`. From that moment providing `--search-path=swift`
will pick up the extractor.
