And use the new project_existential_box to get to the address value.
SILGen now generates a project_existential_box for each alloc_existential_box.
And IRGen re-uses the address value from the alloc_existential_box if the operand of project_existential_box is an alloc_existential_box.
This lets the generated code be the same as before.
Also provide several possible syntaxes for marking an entity as versioned.
None of the syntax in this document is set in stone. (Even these three
options are just examples of three different approaches.)
And use project_box to get to the address value.
SILGen now generates a project_box for each alloc_box.
And IRGen re-uses the address value from the alloc_box if the operand of project_box is an alloc_box.
This lets the generated code be the same as before.
Other than that most changes of this (quite large) commit are straightforward.
Fixes:
* blank line at end of file
* closing bracket does not match indentation of opening bracket's line
* continuation line over-indented for hanging indent
* continuation line over-indented for visual indent
* continuation line unaligned for hanging indent
* inline comment should start with '# '
* missing whitespace around arithmetic operator
* missing whitespace around bitwise or shift operator
* multiple imports on one line
* multiple spaces after ':'
* multiple spaces after operator
In swift 1.2, `Slice` has been renamed `ArraySlice`.
In swift 2.0, type parameter name of `Array` is changed from `T` to `Element`.
Therefore, modified the names which appear in code comments and a document.
In swift 2.0, type parameter name of `Set` is changed from `T` to `Element`.
Therefore, modified the names which appear in code comments and a document.
(but not all of it)
- Add a note about throwing functions becoming non-throwing.
- Clarify that let-properties may not be turned into read-only vars.
- Permit new static stored properties on fixed_layout structs.
- Drop note about "fixed_layout-since-first-available".
- Add note disparaging the utility of @fixed.
- Add note about adding defaulted associated types to protcols.
- Clarify which members can and cannot be added to a class.
- Add some class-specific permitted changes.
- Note that adding/removing 'dynamic' is /not/ permitted.
- Split up protocol and non-protocol extensions.
- Explain why the 'no_payload' performance assertion isn't needed.
Saving the rest of the feedback for the next major content addition.
Update the Library Evolution ("Resilience") doc with a listing for every
top-level declaration kind (...except operators and imports, TODO) that
describes what should be an ABI-compatible change between releases of a
binary library shipped independently of a client app (say, because it's
part of the OS). Restructure the existing discussion of "fragility
attributes" to describe how each of those capabilities is affected when,
say, marking a struct as "fixed-layout".
Still a work in progress, and if something unexpected catches your eye
I'd like to hear about it. Note also that this does /not/ describe how
Swift behaves today; we still make many assumptions about types that
will not be valid in a "resilient" world.
Having a separate address and container value returned from alloc_stack is not really needed in SIL.
Even if they differ we have both addresses available during IRGen, because a dealloc_stack is always dominated by the corresponding alloc_stack in the same function.
Although this commit quite large, most changes are trivial. The largest non-trivial change is in IRGenSIL.
This commit is a NFC regarding the generated code. Even the generated SIL is the same (except removed #0, #1 and @local_storage).
If this semantic tag is applied to a function, then we know that:
- The function does not touch any reference counted objects.
- After the function is executed, all reference counted objects are leaked
(most likely in preparation for program termination).
This allows one, when performing ARC code motion, to ignore blocks that contain
an apply to this function as long as the block does not have any other side
effect having instructions.
I have wanted to do this for a while but was stymied by lacking the ability to
apply multiple @_semantics attributes. This is now committed to trunk so I added
this attribute instead of pattern matching against fatalError (since there could
be other functions with this property).
rdar://19592537
