mirror of
https://github.com/carbon-language/carbon-lang.git
synced 2026-10-04 22:02:52 +01:00
Jon Ross-PerkinsandDana Jansens
5e3bb523f8
This is in support of a goal of changing the blanket `destroy` impl to
use (roughly):
```
private fn CanAggregateDestroy() -> type = "type.can_aggregate_destroy";
// Handles aggregate type destruction.
impl forall [AggregateDestroyT:! CanAggregateDestroy()] AggregateDestroyT as Destroy {
fn Op[addr self: Self*]() = "type.aggregate_destroy";
}
```
That isn't done here because there's still other issues that migrating
raises. What this *does* do is add the builtin functions, and in
particular, support to `FacetTypeInfo` to make `CanAggregateDestroy`
work.
The "special requirement" approach in `FacetTypeInfo` allows us to
support restricting a blanket impl under the current approach of impls.
Maybe we'll find a cleaner approach that can work in the future, but
this fits into the current model by propagating similar to other
requirements. I'm using an enum mask because we have a number of similar
things to add (e.g. copy, move) but I'm not sure we need a full vector.
A few alternatives considered were:
- Supporting syntax more like `where .Self impls
TypeCanAggregateDestroy(.Self, SupportedInterface,
UnsupportedInterface)`. I think it'd be a little cleaner, but requires
better compile-time evaluation in order to assess the type of the call.
Right now it's expected to be a `FacetType` too early to make this work,
and I was concerned about pouring too much more time down this route.
- Providing an actual interface, in particular doing name lookup back
into `Core.` for an interface. This would've added name lookup overhead,
and the question of whether an `impl` exists.
- Generating an interface. This avoids the name lookup, but would still
raise the question of whether an `impl` should also be generated. Work
I've previously done generating interfaces for class destruction also
feels complex to both write and understand (an unfortunate issue).
- Still modeling as an `ImplsConstraint`, for example by defining a
special `InterfaceId::CanAggregateDestroy = -2` similar to what we do on
other ids. I was hesitant because of how this expands the number of
modes of `InterfaceId`, and things for consuming code to watch out for,
for what feels like a relatively niche set of use-cases that are only
interface-like.
---------
Co-authored-by: Dana Jansens <danakj@orodu.net>
71 lines
3.9 KiB
Plaintext
71 lines
3.9 KiB
Plaintext
// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
|
|
// Exceptions. See /LICENSE for license information.
|
|
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
|
//
|
|
// INCLUDE-FILE: toolchain/testing/testdata/min_prelude/int.carbon
|
|
//
|
|
// AUTOUPDATE
|
|
// TIP: To test this file alone, run:
|
|
// TIP: bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/where_expr/non_generic.carbon
|
|
// TIP: To dump output, run:
|
|
// TIP: bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/where_expr/non_generic.carbon
|
|
|
|
interface I { let T:! type; }
|
|
|
|
// Ensure that we don't crash when checking this `where` in a non-generic context.
|
|
//@dump-sem-ir-begin
|
|
fn NotGenericF(U: I where .T == i32) {}
|
|
//@dump-sem-ir-end
|
|
|
|
// CHECK:STDOUT: --- non_generic.carbon
|
|
// CHECK:STDOUT:
|
|
// CHECK:STDOUT: constants {
|
|
// CHECK:STDOUT: %I.type: type = facet_type <@I> [concrete]
|
|
// CHECK:STDOUT: %I.assoc_type: type = assoc_entity_type @I [concrete]
|
|
// CHECK:STDOUT: %assoc0: %I.assoc_type = assoc_entity element0, @I.%T [concrete]
|
|
// CHECK:STDOUT: %.Self: %I.type = bind_symbolic_name .Self [symbolic_self]
|
|
// CHECK:STDOUT: %.Self.as_type: type = facet_access_type %.Self [symbolic_self]
|
|
// CHECK:STDOUT: %I.lookup_impl_witness: <witness> = lookup_impl_witness %.Self, @I [symbolic_self]
|
|
// CHECK:STDOUT: %impl.elem0: type = impl_witness_access %I.lookup_impl_witness, element0 [symbolic_self]
|
|
// CHECK:STDOUT: %int_32: Core.IntLiteral = int_value 32 [concrete]
|
|
// CHECK:STDOUT: %i32: type = class_type @Int, @Int(%int_32) [concrete]
|
|
// CHECK:STDOUT: %I_where.type: type = facet_type <@I where TODO> [concrete]
|
|
// CHECK:STDOUT: %pattern_type.917: type = pattern_type %I_where.type [concrete]
|
|
// CHECK:STDOUT: %NotGenericF.type: type = fn_type @NotGenericF [concrete]
|
|
// CHECK:STDOUT: %NotGenericF: %NotGenericF.type = struct_value () [concrete]
|
|
// CHECK:STDOUT: }
|
|
// CHECK:STDOUT:
|
|
// CHECK:STDOUT: imports {
|
|
// CHECK:STDOUT: }
|
|
// CHECK:STDOUT:
|
|
// CHECK:STDOUT: file {
|
|
// CHECK:STDOUT: %NotGenericF.decl: %NotGenericF.type = fn_decl @NotGenericF [concrete = constants.%NotGenericF] {
|
|
// CHECK:STDOUT: %U.patt: %pattern_type.917 = binding_pattern U [concrete]
|
|
// CHECK:STDOUT: %U.param_patt: %pattern_type.917 = value_param_pattern %U.patt, call_param0 [concrete]
|
|
// CHECK:STDOUT: } {
|
|
// CHECK:STDOUT: %U.param: %I_where.type = value_param call_param0
|
|
// CHECK:STDOUT: %.loc17_21.1: type = splice_block %.loc17_21.2 [concrete = constants.%I_where.type] {
|
|
// CHECK:STDOUT: %I.ref: type = name_ref I, file.%I.decl [concrete = constants.%I.type]
|
|
// CHECK:STDOUT: <elided>
|
|
// CHECK:STDOUT: %.Self.ref: %I.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
|
|
// CHECK:STDOUT: %T.ref: %I.assoc_type = name_ref T, @T.%assoc0 [concrete = constants.%assoc0]
|
|
// CHECK:STDOUT: %.Self.as_type: type = facet_access_type %.Self.ref [symbolic_self = constants.%.Self.as_type]
|
|
// CHECK:STDOUT: %.loc17_27: type = converted %.Self.ref, %.Self.as_type [symbolic_self = constants.%.Self.as_type]
|
|
// CHECK:STDOUT: %impl.elem0: type = impl_witness_access constants.%I.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
|
|
// CHECK:STDOUT: %int_32: Core.IntLiteral = int_value 32 [concrete = constants.%int_32]
|
|
// CHECK:STDOUT: %i32: type = class_type @Int, @Int(constants.%int_32) [concrete = constants.%i32]
|
|
// CHECK:STDOUT: %.loc17_21.2: type = where_expr %.Self [concrete = constants.%I_where.type] {
|
|
// CHECK:STDOUT: requirement_base_facet_type constants.%I.type
|
|
// CHECK:STDOUT: requirement_equivalent %impl.elem0, %i32
|
|
// CHECK:STDOUT: }
|
|
// CHECK:STDOUT: }
|
|
// CHECK:STDOUT: %U: %I_where.type = bind_name U, %U.param
|
|
// CHECK:STDOUT: }
|
|
// CHECK:STDOUT: }
|
|
// CHECK:STDOUT:
|
|
// CHECK:STDOUT: fn @NotGenericF(%U.param: %I_where.type) {
|
|
// CHECK:STDOUT: !entry:
|
|
// CHECK:STDOUT: return
|
|
// CHECK:STDOUT: }
|
|
// CHECK:STDOUT:
|