carbon-language/carbon-lang
1
0
Fork 0
mirror of https://github.com/carbon-language/carbon-lang.git synced 2026-10-04 22:02:52 +01:00
Code Issues Packages Projects Releases 10 Wiki Activity

Implement ...where .Self impls... (#5238)

Browse Source 
* Also remove facet type deduction, since we decided against it on
[2025-04-02](https://docs.google.com/document/d/1Iut5f2TQBrtBNIduF4vJYOKfw7MbS8xH_J01_Q4e6Rk/edit?pli=1&resourcekey=0-mc_vh5UzrzXfU4kO-3tOjA&tab=t.0#heading=h.95phmuvxog9n).

---------

Co-authored-by: Josh L <josh11b@users.noreply.github.com>
Co-authored-by: Dana Jansens <danakj@orodu.net>
This commit is contained in:
josh11b
2025-04-07 20:45:45 +00:00
committed by GitHub
co-authored by Josh L Dana Jansens
parent 87f0e9723f
commit 4af0c8f8d1
27 changed files with 1409 additions and 399 deletions
Download Patch File Download Diff File Expand all files Collapse all files
toolchain/check/eval.cpp
+69 -3
View File
@@ -592,9 +592,16 @@ static auto GetConstantFacetTypeInfo(EvalContext& eval_context,
Phase* phase) -> SemIR::FacetTypeInfo {
const auto& orig = eval_context.facet_types().Get(facet_type_id);
SemIR::FacetTypeInfo info;
info.impls_constraints.reserve(orig.impls_constraints.size());
for (const auto& interface : orig.impls_constraints) {
info.impls_constraints.push_back(
info.extend_constraints.reserve(orig.extend_constraints.size());
for (const auto& interface : orig.extend_constraints) {
info.extend_constraints.push_back(
{.interface_id = interface.interface_id,
.specific_id =
GetConstantValue(eval_context, interface.specific_id, phase)});
}
info.self_impls_constraints.reserve(orig.self_impls_constraints.size());
for (const auto& interface : orig.self_impls_constraints) {
info.self_impls_constraints.push_back(
{.interface_id = interface.interface_id,
.specific_id =
GetConstantValue(eval_context, interface.specific_id, phase)});
@@ -1816,6 +1823,34 @@ auto TryEvalTypedInst<SemIR::BindSymbolicName>(EvalContext& eval_context,
return MakeConstantResult(eval_context.context(), bind, phase);
}
static auto IsPeriodSelf(EvalContext& eval_context, SemIR::ConstantId const_id)
-> bool {
// This also rejects the singleton Error value as it's concrete.
if (!const_id.is_symbolic()) {
return false;
}
const auto& symbolic =
eval_context.constant_values().GetSymbolicConstant(const_id);
// Fast early reject before doing more expensive operations.
if (symbolic.dependence != SemIR::ConstantDependence::PeriodSelf) {
return false;
}
auto inst_id = symbolic.inst_id;
// Unwrap the `FacetAccessType` instruction, which we get when the `.Self` is
// converted to `type`.
if (auto facet_access_type =
eval_context.insts().TryGetAs<SemIR::FacetAccessType>(inst_id)) {
inst_id = facet_access_type->facet_value_inst_id;
}
if (auto bind_symbolic_name =
eval_context.insts().TryGetAs<SemIR::BindSymbolicName>(inst_id)) {
const auto& bind_name =
eval_context.entity_names().Get(bind_symbolic_name->entity_name_id);
return bind_name.name_id == SemIR::NameId::PeriodSelf;
}
return false;
}
// TODO: Convert this to an EvalConstantInst instruction. This will require
// providing a `GetConstantValue` overload for a requirement block.
template <>
@@ -1856,6 +1891,37 @@ auto TryEvalTypedInst<SemIR::WhereExpr>(EvalContext& eval_context,
UpdatePhaseIgnorePeriodSelf(eval_context, rhs, &phase);
info.rewrite_constraints.push_back(
{.lhs_const_id = lhs, .rhs_const_id = rhs});
} else if (auto impls =
eval_context.insts().TryGetAs<SemIR::RequirementImpls>(
inst_id)) {
SemIR::ConstantId lhs = eval_context.GetConstantValue(impls->lhs_id);
SemIR::ConstantId rhs = eval_context.GetConstantValue(impls->rhs_id);
if (rhs != SemIR::ErrorInst::SingletonConstantId &&
IsPeriodSelf(eval_context, lhs)) {
auto rhs_inst_id = eval_context.constant_values().GetInstId(rhs);
if (rhs_inst_id == SemIR::TypeType::SingletonInstId) {
// `.Self impls type` -> nothing to do.
} else {
auto facet_type =
eval_context.insts().GetAs<SemIR::FacetType>(rhs_inst_id);
SemIR::FacetTypeInfo more_info = GetConstantFacetTypeInfo(
eval_context, facet_type.facet_type_id, &phase);
// The way to prevent lookup into the interface requirements of a
// facet type is to put it to the right of a `.Self impls`, which we
// accomplish by putting them into `self_impls_constraints`.
llvm::append_range(info.self_impls_constraints,
more_info.extend_constraints);
llvm::append_range(info.self_impls_constraints,
more_info.self_impls_constraints);
// Other requirements are copied in.
llvm::append_range(info.rewrite_constraints,
more_info.rewrite_constraints);
info.other_requirements |= more_info.other_requirements;
}
} else {
// TODO: Handle `impls` constraints beyond `.Self impls`.
info.other_requirements = true;
}
} else {
// TODO: Handle other requirements
info.other_requirements = true;