The `@export(interface)` and `@export(implementation)` attributes
SE-0497 are queried directly on AST nodes in several places within the
SIL pipeline. However, they don't persist when SIL functions are
serialized, meaning that clients of the original module might make
different assumptions about the availability of a given function's
definition.
Represent these attributes in a SIL function (as an optional
CodeGenerationModel), (de-)serialize them into the module, and add a
textual representation as SIL function attributes `[export_interface]`
and `[export_implementation]`.
The asmname attribute allows one to specify the name that will be used
when lowering a given SIL declaration to LLVM IR. It is not currently
exposed in the surface language.
Make sure this attribute round-trips through the parser and
serialization.
Part of rdar://137014448O.
With a focus on updating the documentation of Ownership SSA.
The main changes are:
* Created a new directory `docs/SIL` and moved all SIL-related files into this directory.
* Converted `rst` files to markdown.
* Extracted sections from `SIL.md` which go into very much detail - including the instruction reference - into separate files: `Types.md`, `Ownership.md`, `FunctionAttributes.md`, `Instructions.md`. Those files are referenced from `SIL.md` at the relevant places.
* Rewrote and updated the OSSA part in `SIL.md`
* Removed a few sections, which are not relevant anymore, like "Value dependency" (which is replaced by ownership concepts).
* Fixed and improved a lot of small things.
Doug Gregor
Erik Eckstein