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
Previous to this change, the initial inspection of the -{enable,disable}-batch-mode
flag was made separate from the subsequent overriding by -wmo; this in turn meant
that the driver might decide it's "in batch mode" in one place (in particular,
when judging whether to ignore the -num-threads flag) and "in wmo mode" elsewhere
(when judging whether to emit one or multiple outputs, which depends on the
-num-threads flag).
Divergence between these two views caused the driver to effectively drop
the -num-threads flag even when overriding batch mode with wmo; since xcode
assumes that passing -wmo -num-threads _will_ cause multiple outputs, this
in turn caused linking to fail since the expected output files were not found.
* In full compilation '-c' with '-emit-module', output duplicated build
record file for full compilation *and* emit module ('~moduleonly') mode.
* In '-emit-module' only mode, use '~moduleonly' build record.
Adds a -working-directory option which can be used to modify how
relative paths are resolved. It affects all other paths used in driver
options (controlled by a new ArgumentIsPath flag on options) as well as
the contents of output file maps and auxilliary file paths generated
implicitly by the compiler itself.
rdar://37713856
