This provides a very rudimentary way to check the end-to-end performance
of simple sourcekitd requests. A sample invocation might be
```
sourcekitd-test -time-request -repeat-request=10 -dont-print-response -req= ...
```
When generating a compiler invocation in driver::createCompilerInvocation()
we end up using filelists if the number of inputs is > 128 (to work around
command line arg limits). We never actually write them out though, and so
fail when parsing the frontend arguments that reference them.
As this function is called frequently by SourceKit and command line limits
aren't a concern here, this patch makes the 128 threshold value configurable
via a new -driver-filelist-threshold option. This is set to its maximum value
in driver::createCompilerInvocation() to ensure filelists aren't used. This
new option makes the existing -driver-use-filelists (that forces filelists to
be used) redundant as it's now equivalent to -driver-filelist-threshold=0.
Resolves rdar://problem/38231888
This converts the instances of the pattern for which we have a proper
substitution in lit. This will make it easier to replace it
appropriately with Windows equivalents.
Stop parsing frontend arguments directly and use the driver instead. The
most intersting part of this change is that it forces us to consider
whether our compiler invocation will have inputs or not. We have
several kinds of requests that need to create a compiler instance, but
not parse any inputs (interface-generation, doc-info, and indexing when
operating on a module instead of source files).
Incidentally, add an error when trying to do doc-info on multiple source
files. This was already very broken (assertion failures and bogus source
locations), so add an error for it.
rdar://problem/17897287
... and add a few basic statistics about the number of requests, ASTs
built, etc. The Statistic type is loosely based on the one from LLVM,
but suitable for using without DEBUG macros and using SourceKit UIdents
to identify the statistic. The easiest way to add a new statistic is to
add it to SwiftStatistics.def in the SwiftLangSupport.
Added "-help" option to Options.td
Added also:
* Added "OPT_HELP" case in the main TestOptions.cpp switch. It uses the llvm options help functionality to provide up-to-date help
* Additional "Use -help for assistance" at the end of the error message that appears when calling an unknown option
Added their following tests, respectively::
* usage.swift, and
* wrong_arguments.swift
Extra: FIXME: in TestOptions::printHelp, suggesting a possible expansion for the printHelp option (details in file)
