These APIs are useful e.g. for quickly finding pre-specialisations by their names.
The existence check is very light-weight and does not try to deserialize bodies of SIL functions.
Headers in include/ are meant to be used across libraries, headers in lib/
are only used within that library.
Thanks @jrose-apple for pointing this out.
The main idea here is that we really, really want to be
able to recover the protocol requirement of a conformance
reference even if it's abstract due to the conforming type
being abstract (e.g. an archetype). I've made the conversion
from ProtocolConformance* explicit to discourage casual
contamination of the Ref with a null value.
As part of this change, always make conformance arrays in
Substitutions fully parallel to the requirements, as opposed
to occasionally being empty when the conformances are abstract.
As another part of this, I've tried to proactively fix
prospective bugs with partially-concrete conformances, which I
believe can happen with concretely-bound archetypes.
In addition to just giving us stronger invariants, this is
progress towards the removal of the archetype from Substitution.
This was once used in lldb but no longer is. I'm cannot find any other
users, so I'm removing it as a small part of cleaning up and simplifying
the SIL linking process.
This feature is required for the implementation of pre-specialization, because one needs to check if a specialized SIL function with a given name exists in the standard library.
Swift SVN r30307
Previous attempts to update the callgraph explicitly after calls to
linkFunction() weren't completely effective because we can deserialize
deeply and introduce multiple new function bodies in the process.
This gets us a bit closer, but only adds new call graph nodes. It does
not currently add edges for everything that gets deserialized (and this
is not fatal, so it is a step forward).
Swift SVN r27120
Before, providing a full SILFunction declaration object with a proper SILType was the only way to link a function. And constructing such a SILFunction declaration by hand using low-level SIL APIs is very annoying and requires a lot of code to be written. This new linkFunction API allows for a lookup using SILDeclRef and essentially performs linking of a SILFunction by its mangled name (assuming this name is unique), which is much easier to invoke. The new API is useful, e.g. when you need to link a well-known function from a standard library.
Swift SVN r26252
This is only used by SILModule but is not integral to a SILModule so it makes
sense to have it in its own file. It keeps SILModule.cpp more focused. We still
keep it in a private header though since it is only meant to be used by
SILModule.cpp.
Swift SVN r25985
