These are defined with macros like errors/warnings/notes, and
make use of format strings and diagnostic arguments. The intent
is to leverage diagnostic arguments in the future to disambiguate
ambiguously spelled types.
Ported a few miscellaneous fix-its to the new system
Now that we've moved to C++14, we no longer need the llvm::make_unique
implementation from STLExtras.h. This patch is a mechanical replacement
of (hopefully) all the llvm::make_unique instances in the swift repo.
Add `llvm_unreachable` to mark covered switches which MSVC does not
analyze correctly and believes that there exists a path through the
function without a return value.
In batch mode, when using serialized diagnostics, we have a
FileSpecificDiagnosticConsumer splitting diags out to separate .dia files (one
per primary). This constructs a mapping from filenames to consumers when it's
first given a diag. So far so good.
It assumes, however, that there are source buffers to be found for each input
file it knows the name of. This is true -- and useful to assert -- once the
source buffers are set up. It's also a prerequisite for building the map it
uses to direct diags.
Unfortunately there's a small window between the consumer being built and the
source manager getting buffers, and in this window we attach to a bridging PCH.
If that attaching generates a diag of itself (say due to a bogus module map or
such) then the diag consumer is asked to build its map without source buffers.
The thing to do here is just to fall back to the "no mapping found" case; the
only tricky part is identifying when we're in that window of time. I've chosen
to use the approximating condition of "none of the file buffers exist at all".
