The generic call `S.foo()` was evaluated with the
capture scope of the owner decl (i.e the `test` block), when it should
use the capture scope of the function declaration.
Most of this migration was performed automatically with `zig fmt`. There
were a few exceptions which I had to manually fix:
* `@alignCast` and `@addrSpaceCast` cannot be automatically rewritten
* `@truncate`'s fixup is incorrect for vectors
* Test cases are not formatted, and their error locations change
The `Value.eql` function has to test for value equality *as-if* the lhs
value parameter is coerced into the type of the rhs. For tagged unions,
there was a problematic case when the lhs was an anonymous struct,
because in such case the value is empty_struct_value and the type
contains all the value information. But the only type available in the
function was the rhs type.
So the fix involved making `Value.eqlAdvanced` also accept the lhs type,
and then enhancing the logic to handle the case of the `.anon_struct` tag.
closes#12418
Tests run locally:
* test-behavior
* test-cases
The problem was that types of non-anytype parameters were being included
as part of the check to see if generic function instantiations were
equal. Now, Module.Fn additionally stores the information for whether each
parameter is anytype or not. `generic_poison` cannot be used to signal
this because the type is still needed for comptime arguments; in such
case the type will not be present in the newly generated function
prototype.
This presented one additional challenge: we need to compare equality of
two values where one of them is post-coercion and the other is not. So
we make some minor adjustments to `Type.eql` to support this. I think
this small complexity tradeoff is worth it because it means the compiler
does much less work on the hot path that a generic function is called
and there is already an existing matching instantiation.
closes#11146
* In semaStructFields and semaUnionFields we return error.GenericPoison
if one of the field types ends up being generic poison.
- This requires handling function calls and function types taking
this into account when calling `typeRequiresComptime` on the return
type.
* Unrelated: I noticed using Valgrind that struct reification did not
populate the `known_opv` field. After fixing it, the behavior tests
run Valgrind-clean.
* ZIR: use `@ptrCast` to cast between slices instead of exploiting
the fact that stage1 incorrectly allows `@bitCast` between slices.
- A future enhancement will make Zig support `@ptrCast` to directly
cast between slices.
This also fixes a bug that I didn't see causing any problems yet in
generic function instantiation where it would read from a GetOrPutResult
too late.
Also it delays full resolution of generic function type parameters until
after the function body is finished being analyzed.
closes#11291
* std.meta: correct use of `default_value` in reification. stage1
accepted a wrong type for `null`.
* Sema: after instantiating a generic function, if the return type ends
up being a comptime-known type, then we return an error, undoing the
generic function instantiation, and making a comptime function call
instead.
- We also needed to clean up the dependency graph in this case.
* Sema: reified enums set tag_ty_inferred to false since an integer tag
type is provided. This is a limitation of the `@Type` builtin which
will be addressed with #10710.
* Sema: fix resolveInferredErrorSet incorrectly calling
ensureFuncBodyAnalyzed on generic functions.
