|
|
@@ -674,6 +674,32 @@ static auto IsValidExprCategoryForConversionTarget(
|
|
|
}
|
|
|
}
|
|
|
|
|
|
+// Determines whether we can pull a value directly out of an initializing
|
|
|
+// expression of type `type_id` to initialize a target of type `type_id` and
|
|
|
+// kind `target_kind`.
|
|
|
+static auto CanUseValueOfInitializer(const SemIR::File& sem_ir,
|
|
|
+ SemIR::TypeId type_id,
|
|
|
+ ConversionTarget::Kind target_kind)
|
|
|
+ -> bool {
|
|
|
+ if (!IsValidExprCategoryForConversionTarget(SemIR::ExprCategory::Value,
|
|
|
+ target_kind)) {
|
|
|
+ // We don't want a value expression.
|
|
|
+ return false;
|
|
|
+ }
|
|
|
+
|
|
|
+ if (SemIR::InitRepr::ForType(sem_ir, type_id).kind !=
|
|
|
+ SemIR::InitRepr::ByCopy) {
|
|
|
+ // The initializing expression doesn't contain a copy of a value.
|
|
|
+ return false;
|
|
|
+ }
|
|
|
+
|
|
|
+ // If the value representation is a copy of the object representation, we
|
|
|
+ // already have a value of the right form and can use that value directly.
|
|
|
+ auto value_rep = SemIR::ValueRepr::ForType(sem_ir, type_id);
|
|
|
+ return value_rep.kind == SemIR::ValueRepr::Copy &&
|
|
|
+ value_rep.type_id == type_id;
|
|
|
+}
|
|
|
+
|
|
|
// Returns the non-adapter type that is compatible with the specified type.
|
|
|
static auto GetCompatibleBaseType(Context& context, SemIR::TypeId type_id)
|
|
|
-> SemIR::TypeId {
|
|
|
@@ -738,19 +764,9 @@ static auto PerformBuiltinConversion(Context& context, SemIR::LocId loc_id,
|
|
|
// If the source is an initializing expression, we may be able to pull a
|
|
|
// value right out of it.
|
|
|
if (value_cat == SemIR::ExprCategory::Initializing &&
|
|
|
- IsValidExprCategoryForConversionTarget(SemIR::ExprCategory::Value,
|
|
|
- target.kind) &&
|
|
|
- SemIR::InitRepr::ForType(sem_ir, value_type_id).kind ==
|
|
|
- SemIR::InitRepr::ByCopy) {
|
|
|
- auto value_rep = SemIR::ValueRepr::ForType(sem_ir, value_type_id);
|
|
|
- if (value_rep.kind == SemIR::ValueRepr::Copy &&
|
|
|
- value_rep.type_id == value_type_id) {
|
|
|
- // The initializer produces an object representation by copy, and the
|
|
|
- // value representation is a copy of the object representation, so we
|
|
|
- // already have a value of the right form.
|
|
|
- return context.AddInst<SemIR::ValueOfInitializer>(
|
|
|
- loc_id, {.type_id = value_type_id, .init_id = value_id});
|
|
|
- }
|
|
|
+ CanUseValueOfInitializer(sem_ir, value_type_id, target.kind)) {
|
|
|
+ return context.AddInst<SemIR::ValueOfInitializer>(
|
|
|
+ loc_id, {.type_id = value_type_id, .init_id = value_id});
|
|
|
}
|
|
|
}
|
|
|
|
|
|
@@ -998,6 +1014,13 @@ auto Convert(Context& context, SemIR::LocId loc_id, SemIR::InstId expr_id,
|
|
|
: ImplicitAsConversionFailure,
|
|
|
expr_id, target.type_id);
|
|
|
});
|
|
|
+
|
|
|
+ // Pull a value directly out of the initializer if possible and wanted.
|
|
|
+ if (expr_id != SemIR::InstId::BuiltinError &&
|
|
|
+ CanUseValueOfInitializer(sem_ir, target.type_id, target.kind)) {
|
|
|
+ expr_id = context.AddInst<SemIR::ValueOfInitializer>(
|
|
|
+ loc_id, {.type_id = target.type_id, .init_id = expr_id});
|
|
|
+ }
|
|
|
}
|
|
|
|
|
|
// Track that we performed a type conversion, if we did so.
|
Richard Smith