carbon-language/carbon-lang
1
0
Fork 0
mirror of https://github.com/carbon-language/carbon-lang.git synced 2026-10-05 22:02:55 +01:00
Code Issues Packages Projects Releases 10 Wiki Activity

Make FacetAccessType evaluate to SymbolicBindingType for type-of a BindSymbolicName (#6115)

Browse Source 
The SymbolicBindingType refers to the type value that will be
substituted in for the BindSymbolicName, but holds onto the EntityNameId
from the BindSymbolicName instead of (or in addition to, for now) the
instruction.

The EntityNameId will be used to look in the ScopeStack to find the
witnesses either from the BindSymbolicName instruction, or other
instructions that specify `impls` constraints against the EntityName.

This will allow us to have the `T` in `I(T)` resolve to a `.Self`
reference in the type so that we get type equality with the binding's
type: `T:! I(.Self)`.
This commit is contained in:
Dana Jansens
2025-10-06 18:56:43 +00:00
committed by GitHub
parent bd4d5805dd
commit fe020ee08b
237 changed files with 7827 additions and 7586 deletions
Download Patch File Download Diff File Expand all files Collapse all files
toolchain/check/subst.cpp
+25 -2
View File
@@ -11,6 +11,7 @@
#include "toolchain/sem_ir/copy_on_write_block.h"
#include "toolchain/sem_ir/ids.h"
#include "toolchain/sem_ir/inst.h"
#include "toolchain/sem_ir/typed_insts.h"
namespace Carbon::Check {
@@ -423,6 +424,27 @@ class SubstConstantCallbacks final : public SubstInstCallbacks {
return SubstResult::FullySubstituted;
}
// A symbolic binding `as type` contains the EntityNameId of that symbolic
// binding. If it matches a substitution, then we want to point the
// EntityNameId to the substitution facet value.
if (auto bind =
context().insts().TryGetAs<SemIR::SymbolicBindingType>(inst_id)) {
auto& entity_name = context().entity_names().Get(bind->entity_name_id);
for (auto [bind_index, replacement_id] : substitutions_) {
if (entity_name.bind_index() == bind_index) {
auto replacement_inst_id =
context().constant_values().GetInstId(replacement_id);
inst_id = RebuildNewInst<SemIR::FacetAccessType>(
loc_id_, {
.type_id = SemIR::TypeType::TypeId,
.facet_value_inst_id = replacement_inst_id,
});
return SubstResult::FullySubstituted;
}
}
}
auto entity_name_id = SemIR::EntityNameId::None;
if (auto bind =
context().insts().TryGetAs<SemIR::BindSymbolicName>(inst_id)) {
@@ -435,12 +457,13 @@ class SubstConstantCallbacks final : public SubstInstCallbacks {
return SubstResult::SubstOperands;
}
auto& entity_name = context().entity_names().Get(entity_name_id);
// This is a symbolic binding. Check if we're substituting it.
// TODO: Consider building a hash map for substitutions. We might have a
// lot of them.
for (auto [bind_index, replacement_id] : substitutions_) {
if (context().entity_names().Get(entity_name_id).bind_index() ==
bind_index) {
if (entity_name.bind_index() == bind_index) {
// This is the binding we're replacing. Perform substitution.
inst_id = context().constant_values().GetInstId(replacement_id);
return SubstResult::FullySubstituted;