* Move the mutating APIs into Context.swift, because SIL can only be mutated through a MutatingContext
* move the `baseOperand` and `base` properties from the instruction classes to the `MarkDependenceInstruction` protocol
* add `valueOrAddressOperand` and `valueOrAddress` in the `MarkDependenceInstruction` protocol
Diagnostics only work with `SourceLoc` which is basically a pointer into a buffer of the loaded source file.
But when debug info is de-serialized, the SIL `Location` consists of a filename+line+column.
To "convert" this to a `SourceLoc`, the file must be loaded.
This change adds `DiagnosticEngine.getLocationFromExternalSource` for this purpose.
Also, the new protocol `ProvidingSourceLocation` - to which `SourceLoc` and `Location` conform - help to generalize the helper struct `Diagnostic` and make this "conversion" happen automatically.
Add a `vectorBase` field kind which corresponds to `vector_base_addr`.
Also, improve `mayOverlap`: it didn't catch the case that the first element of a vector cannot overlap with another element.
It derives the address of the first element of a vector, i.e. a `Builtin.FixedArray`, from the address of the vector itself.
Addresses of other vector elements can then be derived with `index_addr`.
These APIs are quite convoluted. The checks for var_decl need to be performed in
just the right order. The is a consequence of complexity in the SIL
representation itself, not a problem with the APIs.
It is common for code to accidentally call a less-complete form of the API. It
is essential that they be defined in a central location, and the we get the same
answer whether we start with an Instruction, Argument, or Value. The primary
public interface should always check for debug_value users. The varDecl property
is actually an implementation detail.
It is questionable whether a function like findVarDecl() that returns a basic
property of SIL and does not require arguments should be a property instead. It
is a function to hint that it may scan the use-list, which is not something
we normally want SIL properties to do. Use-lists can grow linearly in function
size. But, again, this is a natural result of the SIL representation and needs
to be considered an implementation detail.
Add a note explaining that dependence on closure captures is not
supported. Otherwise, the diagnostics are very confusing:
"it depends on a closure capture; this is not yet supported"
* rename `ScopedInstruction.endOperands` -> `scopeEndingOperands`
* let them behave the same way. For `load_borrow` there was a difference because `endOperands` didn't consider branches to re-borrow phis.
Allow a dependency on a local [read] access scope to be transfered to the
caller's [modify] access.
Fixes rdar://149560133 (Invalid lifetime dependence error when
trying to return Span from an inout argument)
Add support for returnValue phis (e.g. to return an Optional .some or .none).
Fixes rdar://149397018 (Wrapping non escapable in an Optional
(or any copy lifetime wrapper) is an escape)
If the method is a default witness methods (`selfType` != nil) it has generic self type.
In this case the generic self parameter is at depth 0 and the actual generic parameters of the substitution map are at depth + 1, e.g:
```
@convention(witness_method: P) <τ_0_0><τ_1_0 where τ_0_0 : GenClass<τ_1_0>.T>
^ ^
self params of substitution map at depth + 1
```
* move it from the SIL to the AST module (where it belongs)
* change the signature of `diagnose` from `diagnose(location, .some_error)` to `diagnose(.some_error, at: location)`
* add an overload to allow passing a `SIL.Location` directly to `diagnose`
* add a `Diagnostic : Error` utility struct which allows throwing a `Diagnostic`
Store specialize witness tables in a separate lookup table in the module. This allows that for a normal conformance there can exist the original _and_ a specialized witness table.
Also, add a boolean property `isSpecialized` to `WitnessTable` which indicates whether the witness table is specialized or not.