Reformatting everything now that we have `llvm` namespaces. I've
separated this from the main commit to help manage merge-conflicts and
for making it a bit easier to read the mega-patch.
This is phase-1 of switching from llvm::Optional to std::optional in the
next rebranch. llvm::Optional was removed from upstream LLVM, so we need
to migrate off rather soon. On Darwin, std::optional, and llvm::Optional
have the same layout, so we don't need to be as concerned about ABI
beyond the name mangling. `llvm::Optional` is only returned from one
function in
```
getStandardTypeSubst(StringRef TypeName,
bool allowConcurrencyManglings);
```
It's the return value, so it should not impact the mangling of the
function, and the layout is the same as `std::optional`, so it should be
mostly okay. This function doesn't appear to have users, and the ABI was
already broken 2 years ago for concurrency and no one seemed to notice
so this should be "okay".
I'm doing the migration incrementally so that folks working on main can
cherry-pick back to the release/5.9 branch. Once 5.9 is done and locked
away, then we can go through and finish the replacement. Since `None`
and `Optional` show up in contexts where they are not `llvm::None` and
`llvm::Optional`, I'm preparing the work now by going through and
removing the namespace unwrapping and making the `llvm` namespace
explicit. This should make it fairly mechanical to go through and
replace llvm::Optional with std::optional, and llvm::None with
std::nullopt. It's also a change that can be brought onto the
release/5.9 with minimal impact. This should be an NFC change.
Using std::string in the function signature copies the constant string
into a stack allocated copy, which is the one referenced by the
StringRef that DiagnosticInfo stores. when the stack is abandoned, the
string seems to be modificed in VC++, which makes the test fail in
Windows.
Using const char * in the signature avoids the std::string creation, and
StringRef will refer to the static data instead.
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.
It turns out that we need to have the diagnostic consumers set up
before we've actually opened the input files, which makes sense
because we might want to emit diagnostics about not being able to open
an input file. Switch to using file names instead, and mapping those
over to source ranges only once we actually need to handle a
diagnostic with a valid source location.
If a top-level diagnostic is in a particular source range, the
RangeSpecificDiagnosticConsumer will funnel it and any attached notes
to a particular "sub-consumer" designated for that range (intended to
be used with whole files). If it's not in a range designated for any
sub-consumer, the diagnostic is passed to all registered
sub-consumers.
This is intended to be used for batch mode, so that diagnostics that
are definitely associated with a particular file can be emitted in
that file's .dia output, while diagnostics that may be associated with
other files (such as those that come from Clang) will still get
presented to the user.
