SwiftSourceInfo files provide source location information for decls coming from
loaded modules. For most IDE use cases it either has an undesirable impact on
performance with no benefit (code completion), results in stale locations being
used instead of more up-to-date indexer locations (cursor info), or has no
observable effect (live diagnostics, which are filtered to just those with a
location in the primary file).
For non-IDE clients of SourceKit though, cursor info providing declaration
locations for symbols from other modules is useful, so add a global
configuration option (and a new request to set it) to control whether
.swiftsourceinfo files are loaded or not based on use case (they are loaded by
default).
This removes the custom `LINK_LIBS` in favour of
`target_link_libraries`. This simplifies the custom functions that we
have for adding libraries, makes it easier to query the information from
ninja and will allow us to slowly remove more of the custom logic for
building the products.
`source.request.conformingmethods` is a new SourceKit request which
receives a source position and a list of protocol namses, returns a list
of methods whose return type conforms to the requested protocols.
rdar://problem/44699573
This is a new SourceKit request which receives a position in the source
file, returns possible expected types and their members which can be
referenced by "implicit member expression" syntax.
Currently, SourceKit's CMake functions all use DEPENDS to specify
libraries the targets will link with. This is confusing as it doesn't
behave the same way that add_swift behaves, and implies that
dependencies are created when there aren't.
The code goes into its own sub-tree under 'tools' but tests go under 'test',
so that running 'check-swift' will also run all the SourceKit tests.
SourceKit is disabled on non-darwin platforms.
