Mostly fix lowering. Enums are still broken.

Author: zygoloid

toolchain/check/convert.cpp

@@ -1282,16 +1282,21 @@ static auto IsCppEnum(Context& context, SemIR::TypeId type_id) -> bool {
 }
 
 // Given a value expression, form a corresponding initializer that copies from
-// that value, if it is possible to do so.
-static auto PerformCopy(Context& context, SemIR::InstId expr_id, bool diagnose)
-    -> SemIR::InstId {
+// that value to the specified target, if it is possible to do so.
+static auto PerformCopy(Context& context, SemIR::InstId expr_id,
+                        SemIR::InstId target_id, PendingBlock& target_block,
+                        bool diagnose) -> SemIR::InstId {
   // TODO: We don't have a mechanism yet to generate `Copy` impls for each enum
   // type imported from C++. For now we fake it by providing a direct copy.
-  if (IsCppEnum(context, context.insts().Get(expr_id).type_id())) {
-    return CopyValueToTemporary(context, expr_id);
+  auto type_id = context.insts().Get(expr_id).type_id();
+  if (IsCppEnum(context, type_id)) {
+    target_block.InsertHere();
+    return AddInst<SemIR::InitializeFrom>(
+        context, SemIR::LocId(expr_id),
+        {.type_id = type_id, .src_id = expr_id, .dest_id = target_id});
   }
 
-  return BuildUnaryOperator(
+  auto copy_id = BuildUnaryOperator(
       context, SemIR::LocId(expr_id), {"Copy"}, expr_id, [&] {
         if (!diagnose) {
           return context.emitter().BuildSuppressed();
@@ -1300,6 +1305,8 @@ static auto PerformCopy(Context& context, SemIR::InstId expr_id, bool diagnose)
                           "cannot copy value of type {0}", TypeOfInstId);
         return context.emitter().Build(expr_id, CopyOfUncopyableType, expr_id);
       });
+  MarkInitializerFor(context.sem_ir(), copy_id, target_id, target_block);
+  return copy_id;
 }
 
 // Convert a value expression so that it can be used to initialize a C++ thunk
@@ -1319,7 +1326,10 @@ static auto ConvertValueForCppThunkRef(Context& context, SemIR::InstId expr_id,
 
   // Otherwise, we need a temporary to pass as the thunk argument. Create a copy
   // and initialize a temporary from it.
-  expr_id = PerformCopy(context, expr_id, diagnose);
+  PendingBlock target_block(&context);
+  auto temporary_id = target_block.AddInst<SemIR::TemporaryStorage>(
+      SemIR::LocId(expr_id), {.type_id = expr.type_id()});
+  expr_id = PerformCopy(context, expr_id, temporary_id, target_block, diagnose);
   return MaterializeIfInitializing(context, expr_id);
 }
 
@@ -1577,7 +1587,8 @@ auto Convert(Context& context, SemIR::LocId loc_id, SemIR::InstId expr_id,
 
       // When initializing from a value, perform a copy.
       if (target.is_initializer()) {
-        expr_id = PerformCopy(context, expr_id, target.diagnose);
+        expr_id = PerformCopy(context, expr_id, target.init_id,
+                              *target.init_block, target.diagnose);
       }
 
       // When initializing a C++ thunk parameter, form a reference, creating a

toolchain/check/testdata/class/generic/basic.carbon

@@ -268,8 +268,8 @@ class Declaration(T:! type);
 // CHECK:STDOUT:   %require_complete.loc11: <witness> = require_complete_type %T.as_type.loc10_32.1 [symbolic = %require_complete.loc11 (constants.%require_complete.ecc)]
 // CHECK:STDOUT:   %Copy.lookup_impl_witness: <witness> = lookup_impl_witness %T, @Copy [symbolic = %Copy.lookup_impl_witness (constants.%Copy.lookup_impl_witness.3ba)]
 // CHECK:STDOUT:   %Copy.facet: %Copy.type = facet_value %T.as_type.loc10_32.1, (%Copy.lookup_impl_witness) [symbolic = %Copy.facet (constants.%Copy.facet.72e)]
-// CHECK:STDOUT:   %.loc11_16.5: type = fn_type_with_self_type constants.%Copy.Op.type, %Copy.facet [symbolic = %.loc11_16.5 (constants.%.671)]
-// CHECK:STDOUT:   %impl.elem0.loc11_16.2: @Class.GetValue.%.loc11_16.5 (%.671) = impl_witness_access %Copy.lookup_impl_witness, element0 [symbolic = %impl.elem0.loc11_16.2 (constants.%impl.elem0.56e)]
+// CHECK:STDOUT:   %.loc11_16.4: type = fn_type_with_self_type constants.%Copy.Op.type, %Copy.facet [symbolic = %.loc11_16.4 (constants.%.671)]
+// CHECK:STDOUT:   %impl.elem0.loc11_16.2: @Class.GetValue.%.loc11_16.4 (%.671) = impl_witness_access %Copy.lookup_impl_witness, element0 [symbolic = %impl.elem0.loc11_16.2 (constants.%impl.elem0.56e)]
 // CHECK:STDOUT:   %specific_impl_fn.loc11_16.2: <specific function> = specific_impl_function %impl.elem0.loc11_16.2, @Copy.Op(%Copy.facet) [symbolic = %specific_impl_fn.loc11_16.2 (constants.%specific_impl_fn.fb7)]
 // CHECK:STDOUT:
 // CHECK:STDOUT:   fn(%self.param: @Class.GetValue.%Class (%Class)) -> %return.param: @Class.GetValue.%T.as_type.loc10_32.1 (%T.as_type) {
@@ -278,13 +278,13 @@ class Declaration(T:! type);
 // CHECK:STDOUT:     %k.ref: @Class.GetValue.%Class.elem (%Class.elem) = name_ref k, @Class.%.loc14_8 [concrete = @Class.%.loc14_8]
 // CHECK:STDOUT:     %.loc11_16.1: ref @Class.GetValue.%T.as_type.loc10_32.1 (%T.as_type) = class_element_access %self.ref, element0
 // CHECK:STDOUT:     %.loc11_16.2: @Class.GetValue.%T.as_type.loc10_32.1 (%T.as_type) = bind_value %.loc11_16.1
-// CHECK:STDOUT:     %impl.elem0.loc11_16.1: @Class.GetValue.%.loc11_16.5 (%.671) = impl_witness_access constants.%Copy.lookup_impl_witness.3ba, element0 [symbolic = %impl.elem0.loc11_16.2 (constants.%impl.elem0.56e)]
+// CHECK:STDOUT:     %impl.elem0.loc11_16.1: @Class.GetValue.%.loc11_16.4 (%.671) = impl_witness_access constants.%Copy.lookup_impl_witness.3ba, element0 [symbolic = %impl.elem0.loc11_16.2 (constants.%impl.elem0.56e)]
 // CHECK:STDOUT:     %bound_method.loc11_16.1: <bound method> = bound_method %.loc11_16.2, %impl.elem0.loc11_16.1
 // CHECK:STDOUT:     %specific_impl_fn.loc11_16.1: <specific function> = specific_impl_function %impl.elem0.loc11_16.1, @Copy.Op(constants.%Copy.facet.72e) [symbolic = %specific_impl_fn.loc11_16.2 (constants.%specific_impl_fn.fb7)]
 // CHECK:STDOUT:     %bound_method.loc11_16.2: <bound method> = bound_method %.loc11_16.2, %specific_impl_fn.loc11_16.1
-// CHECK:STDOUT:     %.loc11_16.3: ref @Class.GetValue.%T.as_type.loc10_32.1 (%T.as_type) = temporary_storage
-// CHECK:STDOUT:     %.loc11_16.4: init @Class.GetValue.%T.as_type.loc10_32.1 (%T.as_type) = call %bound_method.loc11_16.2(%.loc11_16.2) to %.loc11_16.3
-// CHECK:STDOUT:     return %.loc11_16.4 to %return
+// CHECK:STDOUT:     %.loc10_29: ref @Class.GetValue.%T.as_type.loc10_32.1 (%T.as_type) = splice_block %return {}
+// CHECK:STDOUT:     %.loc11_16.3: init @Class.GetValue.%T.as_type.loc10_32.1 (%T.as_type) = call %bound_method.loc11_16.2(%.loc11_16.2) to %.loc10_29
+// CHECK:STDOUT:     return %.loc11_16.3 to %return
 // CHECK:STDOUT:   }
 // CHECK:STDOUT: }
 // CHECK:STDOUT:

toolchain/check/testdata/class/generic/field.carbon

@@ -306,8 +306,8 @@ fn H(U:! Core.Copy, c: Class(U)) -> U {
 // CHECK:STDOUT:   %Class.elem: type = unbound_element_type %Class.loc13_31.1, %T.as_type.loc13_31.1 [symbolic = %Class.elem (constants.%Class.elem.73af90.1)]
 // CHECK:STDOUT:   %Copy.lookup_impl_witness: <witness> = lookup_impl_witness %T.loc13_6.1, @Copy [symbolic = %Copy.lookup_impl_witness (constants.%Copy.lookup_impl_witness.3ba2b3.1)]
 // CHECK:STDOUT:   %Copy.facet: %Copy.type = facet_value %T.as_type.loc13_31.1, (%Copy.lookup_impl_witness) [symbolic = %Copy.facet (constants.%Copy.facet.72ea01.1)]
-// CHECK:STDOUT:   %.loc14_11.5: type = fn_type_with_self_type constants.%Copy.Op.type, %Copy.facet [symbolic = %.loc14_11.5 (constants.%.671c3a.1)]
-// CHECK:STDOUT:   %impl.elem0.loc14_11.2: @G.%.loc14_11.5 (%.671c3a.1) = impl_witness_access %Copy.lookup_impl_witness, element0 [symbolic = %impl.elem0.loc14_11.2 (constants.%impl.elem0.56eb4a.1)]
+// CHECK:STDOUT:   %.loc14_11.4: type = fn_type_with_self_type constants.%Copy.Op.type, %Copy.facet [symbolic = %.loc14_11.4 (constants.%.671c3a.1)]
+// CHECK:STDOUT:   %impl.elem0.loc14_11.2: @G.%.loc14_11.4 (%.671c3a.1) = impl_witness_access %Copy.lookup_impl_witness, element0 [symbolic = %impl.elem0.loc14_11.2 (constants.%impl.elem0.56eb4a.1)]
 // CHECK:STDOUT:   %specific_impl_fn.loc14_11.2: <specific function> = specific_impl_function %impl.elem0.loc14_11.2, @Copy.Op(%Copy.facet) [symbolic = %specific_impl_fn.loc14_11.2 (constants.%specific_impl_fn.fb70c0.1)]
 // CHECK:STDOUT:
 // CHECK:STDOUT:   fn(%c.param: @G.%Class.loc13_31.1 (%Class.b1d614.1)) -> %return.param: @G.%T.as_type.loc13_31.1 (%T.as_type) {
@@ -316,13 +316,13 @@ fn H(U:! Core.Copy, c: Class(U)) -> U {
 // CHECK:STDOUT:     %x.ref: @G.%Class.elem (%Class.elem.73af90.1) = name_ref x, @Class.%.loc6 [concrete = @Class.%.loc6]
 // CHECK:STDOUT:     %.loc14_11.1: ref @G.%T.as_type.loc13_31.1 (%T.as_type) = class_element_access %c.ref, element0
 // CHECK:STDOUT:     %.loc14_11.2: @G.%T.as_type.loc13_31.1 (%T.as_type) = bind_value %.loc14_11.1
-// CHECK:STDOUT:     %impl.elem0.loc14_11.1: @G.%.loc14_11.5 (%.671c3a.1) = impl_witness_access constants.%Copy.lookup_impl_witness.3ba2b3.1, element0 [symbolic = %impl.elem0.loc14_11.2 (constants.%impl.elem0.56eb4a.1)]
+// CHECK:STDOUT:     %impl.elem0.loc14_11.1: @G.%.loc14_11.4 (%.671c3a.1) = impl_witness_access constants.%Copy.lookup_impl_witness.3ba2b3.1, element0 [symbolic = %impl.elem0.loc14_11.2 (constants.%impl.elem0.56eb4a.1)]
 // CHECK:STDOUT:     %bound_method.loc14_11.1: <bound method> = bound_method %.loc14_11.2, %impl.elem0.loc14_11.1
 // CHECK:STDOUT:     %specific_impl_fn.loc14_11.1: <specific function> = specific_impl_function %impl.elem0.loc14_11.1, @Copy.Op(constants.%Copy.facet.72ea01.1) [symbolic = %specific_impl_fn.loc14_11.2 (constants.%specific_impl_fn.fb70c0.1)]
 // CHECK:STDOUT:     %bound_method.loc14_11.2: <bound method> = bound_method %.loc14_11.2, %specific_impl_fn.loc14_11.1
-// CHECK:STDOUT:     %.loc14_11.3: ref @G.%T.as_type.loc13_31.1 (%T.as_type) = temporary_storage
-// CHECK:STDOUT:     %.loc14_11.4: init @G.%T.as_type.loc13_31.1 (%T.as_type) = call %bound_method.loc14_11.2(%.loc14_11.2) to %.loc14_11.3
-// CHECK:STDOUT:     return %.loc14_11.4 to %return
+// CHECK:STDOUT:     %.loc13_34: ref @G.%T.as_type.loc13_31.1 (%T.as_type) = splice_block %return {}
+// CHECK:STDOUT:     %.loc14_11.3: init @G.%T.as_type.loc13_31.1 (%T.as_type) = call %bound_method.loc14_11.2(%.loc14_11.2) to %.loc13_34
+// CHECK:STDOUT:     return %.loc14_11.3 to %return
 // CHECK:STDOUT:   }
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
@@ -339,8 +339,8 @@ fn H(U:! Core.Copy, c: Class(U)) -> U {
 // CHECK:STDOUT:   %Class.elem: type = unbound_element_type %Class.loc17_31.1, %U.as_type.loc17_31.1 [symbolic = %Class.elem (constants.%Class.elem.73af90.2)]
 // CHECK:STDOUT:   %Copy.lookup_impl_witness: <witness> = lookup_impl_witness %U.loc17_6.1, @Copy [symbolic = %Copy.lookup_impl_witness (constants.%Copy.lookup_impl_witness.3ba2b3.2)]
 // CHECK:STDOUT:   %Copy.facet: %Copy.type = facet_value %U.as_type.loc17_31.1, (%Copy.lookup_impl_witness) [symbolic = %Copy.facet (constants.%Copy.facet.72ea01.2)]
-// CHECK:STDOUT:   %.loc18_11.5: type = fn_type_with_self_type constants.%Copy.Op.type, %Copy.facet [symbolic = %.loc18_11.5 (constants.%.671c3a.2)]
-// CHECK:STDOUT:   %impl.elem0.loc18_11.2: @H.%.loc18_11.5 (%.671c3a.2) = impl_witness_access %Copy.lookup_impl_witness, element0 [symbolic = %impl.elem0.loc18_11.2 (constants.%impl.elem0.56eb4a.2)]
+// CHECK:STDOUT:   %.loc18_11.4: type = fn_type_with_self_type constants.%Copy.Op.type, %Copy.facet [symbolic = %.loc18_11.4 (constants.%.671c3a.2)]
+// CHECK:STDOUT:   %impl.elem0.loc18_11.2: @H.%.loc18_11.4 (%.671c3a.2) = impl_witness_access %Copy.lookup_impl_witness, element0 [symbolic = %impl.elem0.loc18_11.2 (constants.%impl.elem0.56eb4a.2)]
 // CHECK:STDOUT:   %specific_impl_fn.loc18_11.2: <specific function> = specific_impl_function %impl.elem0.loc18_11.2, @Copy.Op(%Copy.facet) [symbolic = %specific_impl_fn.loc18_11.2 (constants.%specific_impl_fn.fb70c0.2)]
 // CHECK:STDOUT:
 // CHECK:STDOUT:   fn(%c.param: @H.%Class.loc17_31.1 (%Class.b1d614.2)) -> %return.param: @H.%U.as_type.loc17_31.1 (%U.as_type.565) {
@@ -349,13 +349,13 @@ fn H(U:! Core.Copy, c: Class(U)) -> U {
 // CHECK:STDOUT:     %x.ref: @H.%Class.elem (%Class.elem.73af90.2) = name_ref x, @Class.%.loc6 [concrete = @Class.%.loc6]
 // CHECK:STDOUT:     %.loc18_11.1: ref @H.%U.as_type.loc17_31.1 (%U.as_type.565) = class_element_access %c.ref, element0
 // CHECK:STDOUT:     %.loc18_11.2: @H.%U.as_type.loc17_31.1 (%U.as_type.565) = bind_value %.loc18_11.1
-// CHECK:STDOUT:     %impl.elem0.loc18_11.1: @H.%.loc18_11.5 (%.671c3a.2) = impl_witness_access constants.%Copy.lookup_impl_witness.3ba2b3.2, element0 [symbolic = %impl.elem0.loc18_11.2 (constants.%impl.elem0.56eb4a.2)]
+// CHECK:STDOUT:     %impl.elem0.loc18_11.1: @H.%.loc18_11.4 (%.671c3a.2) = impl_witness_access constants.%Copy.lookup_impl_witness.3ba2b3.2, element0 [symbolic = %impl.elem0.loc18_11.2 (constants.%impl.elem0.56eb4a.2)]
 // CHECK:STDOUT:     %bound_method.loc18_11.1: <bound method> = bound_method %.loc18_11.2, %impl.elem0.loc18_11.1
 // CHECK:STDOUT:     %specific_impl_fn.loc18_11.1: <specific function> = specific_impl_function %impl.elem0.loc18_11.1, @Copy.Op(constants.%Copy.facet.72ea01.2) [symbolic = %specific_impl_fn.loc18_11.2 (constants.%specific_impl_fn.fb70c0.2)]
 // CHECK:STDOUT:     %bound_method.loc18_11.2: <bound method> = bound_method %.loc18_11.2, %specific_impl_fn.loc18_11.1
-// CHECK:STDOUT:     %.loc18_11.3: ref @H.%U.as_type.loc17_31.1 (%U.as_type.565) = temporary_storage
-// CHECK:STDOUT:     %.loc18_11.4: init @H.%U.as_type.loc17_31.1 (%U.as_type.565) = call %bound_method.loc18_11.2(%.loc18_11.2) to %.loc18_11.3
-// CHECK:STDOUT:     return %.loc18_11.4 to %return
+// CHECK:STDOUT:     %.loc17_34: ref @H.%U.as_type.loc17_31.1 (%U.as_type.565) = splice_block %return {}
+// CHECK:STDOUT:     %.loc18_11.3: init @H.%U.as_type.loc17_31.1 (%U.as_type.565) = call %bound_method.loc18_11.2(%.loc18_11.2) to %.loc17_34
+// CHECK:STDOUT:     return %.loc18_11.3 to %return
 // CHECK:STDOUT:   }
 // CHECK:STDOUT: }
 // CHECK:STDOUT: