mirror of
https://github.com/carbon-language/carbon-lang.git
synced 2026-10-01 22:02:45 +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>
88 lines
4.1 KiB
Plaintext
88 lines
4.1 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
|
|
// TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
|
|
// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
|
|
//
|
|
// AUTOUPDATE
|
|
// TIP: To test this file alone, run:
|
|
// TIP: bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/fail_redefinition.carbon
|
|
// TIP: To dump output, run:
|
|
// TIP: bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/fail_redefinition.carbon
|
|
|
|
interface I {}
|
|
|
|
impl i32 as I {}
|
|
|
|
// CHECK:STDERR: fail_redefinition.carbon:[[@LINE+7]]:1: error: redefinition of `impl i32 as I` [ImplRedefinition]
|
|
// CHECK:STDERR: impl i32 as I {}
|
|
// CHECK:STDERR: ^~~~~~~~~~~~~~~
|
|
// CHECK:STDERR: fail_redefinition.carbon:[[@LINE-5]]:1: note: previous definition was here [ImplPreviousDefinition]
|
|
// CHECK:STDERR: impl i32 as I {}
|
|
// CHECK:STDERR: ^~~~~~~~~~~~~~~
|
|
// CHECK:STDERR:
|
|
impl i32 as I {}
|
|
|
|
// CHECK:STDOUT: --- fail_redefinition.carbon
|
|
// CHECK:STDOUT:
|
|
// CHECK:STDOUT: constants {
|
|
// CHECK:STDOUT: %I.type: type = facet_type <@I> [concrete]
|
|
// CHECK:STDOUT: %Self: %I.type = bind_symbolic_name Self, 0 [symbolic]
|
|
// CHECK:STDOUT: %int_32: Core.IntLiteral = int_value 32 [concrete]
|
|
// CHECK:STDOUT: %Int.type: type = generic_class_type @Int [concrete]
|
|
// CHECK:STDOUT: %Int.generic: %Int.type = struct_value () [concrete]
|
|
// CHECK:STDOUT: %i32: type = class_type @Int, @Int(%int_32) [concrete]
|
|
// CHECK:STDOUT: %I.impl_witness: <witness> = impl_witness file.%I.impl_witness_table [concrete]
|
|
// CHECK:STDOUT: }
|
|
// CHECK:STDOUT:
|
|
// CHECK:STDOUT: imports {
|
|
// CHECK:STDOUT: %Core: <namespace> = namespace file.%Core.import, [concrete] {
|
|
// CHECK:STDOUT: .Int = %Core.Int
|
|
// CHECK:STDOUT: import Core//prelude
|
|
// CHECK:STDOUT: import Core//prelude/...
|
|
// CHECK:STDOUT: }
|
|
// CHECK:STDOUT: %Core.Int: %Int.type = import_ref Core//prelude/parts/int, Int, loaded [concrete = constants.%Int.generic]
|
|
// CHECK:STDOUT: }
|
|
// CHECK:STDOUT:
|
|
// CHECK:STDOUT: file {
|
|
// CHECK:STDOUT: package: <namespace> = namespace [concrete] {
|
|
// CHECK:STDOUT: .Core = imports.%Core
|
|
// CHECK:STDOUT: .I = %I.decl
|
|
// CHECK:STDOUT: }
|
|
// CHECK:STDOUT: %Core.import = import Core
|
|
// CHECK:STDOUT: %I.decl: type = interface_decl @I [concrete = constants.%I.type] {} {}
|
|
// CHECK:STDOUT: impl_decl @i32.as.I.impl.36ba5e.1 [concrete] {} {
|
|
// 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: %I.ref: type = name_ref I, file.%I.decl [concrete = constants.%I.type]
|
|
// CHECK:STDOUT: }
|
|
// CHECK:STDOUT: %I.impl_witness_table = impl_witness_table (), @i32.as.I.impl.36ba5e.1 [concrete]
|
|
// CHECK:STDOUT: %I.impl_witness: <witness> = impl_witness %I.impl_witness_table [concrete = constants.%I.impl_witness]
|
|
// CHECK:STDOUT: impl_decl @i32.as.I.impl.36ba5e.2 [concrete] {} {
|
|
// 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: %I.ref: type = name_ref I, file.%I.decl [concrete = constants.%I.type]
|
|
// CHECK:STDOUT: }
|
|
// CHECK:STDOUT: }
|
|
// CHECK:STDOUT:
|
|
// CHECK:STDOUT: interface @I {
|
|
// CHECK:STDOUT: %Self: %I.type = bind_symbolic_name Self, 0 [symbolic = constants.%Self]
|
|
// CHECK:STDOUT:
|
|
// CHECK:STDOUT: !members:
|
|
// CHECK:STDOUT: .Self = %Self
|
|
// CHECK:STDOUT: witness = ()
|
|
// CHECK:STDOUT: }
|
|
// CHECK:STDOUT:
|
|
// CHECK:STDOUT: impl @i32.as.I.impl.36ba5e.1: %i32 as %I.ref {
|
|
// CHECK:STDOUT: !members:
|
|
// CHECK:STDOUT: witness = file.%I.impl_witness
|
|
// CHECK:STDOUT: }
|
|
// CHECK:STDOUT:
|
|
// CHECK:STDOUT: impl @i32.as.I.impl.36ba5e.2: %i32 as %I.ref {
|
|
// CHECK:STDOUT: !members:
|
|
// CHECK:STDOUT: witness = <error>
|
|
// CHECK:STDOUT: }
|
|
// CHECK:STDOUT:
|