From 071f1b6062b459928ebfd6f2f60a8d6ad021112b Mon Sep 17 00:00:00 2001
From: Yong He <yonghe@outlook.com>
Date: Wed, 14 Aug 2024 18:41:48 -0700
Subject: Variadic Generics Part 1: parsing and type checking. (#4833)

---
 source/slang/slang-check-inheritance.cpp | 40 ++++++++++++++++++++++++++++++--
 1 file changed, 38 insertions(+), 2 deletions(-)

(limited to 'source/slang/slang-check-inheritance.cpp')

diff --git a/source/slang/slang-check-inheritance.cpp b/source/slang/slang-check-inheritance.cpp
index 7320d0463..3e59c5e8d 100644
--- a/source/slang/slang-check-inheritance.cpp
+++ b/source/slang/slang-check-inheritance.cpp
@@ -266,7 +266,7 @@ namespace Slang
                 addDirectBaseType(baseType, satisfyingWitness);
             }
         }
-        else if (auto genericTypeParamDeclRef = declRef.as<GenericTypeParamDecl>())
+        else if (auto genericTypeParamDeclRef = declRef.as<GenericTypeParamDeclBase>())
         {
             // The constraints placed on a generic type parameter are siblings of that
             // parameter in its parent `GenericDecl`, so we need to enumerate all of
@@ -298,7 +298,14 @@ namespace Slang
                 //
                 auto subDeclRefType = as<DeclRefType>(subType);
                 if (!subDeclRefType)
-                    continue;
+                {
+                    if (auto subEachType = as<EachType>(subType))
+                    {
+                        subDeclRefType = as<DeclRefType>(subEachType->getElementType());
+                    }
+                    if (!subDeclRefType)
+                        continue;
+                }
                 if (subDeclRefType->getDeclRef() != genericTypeParamDeclRef)
                     continue;
 
@@ -922,6 +929,35 @@ namespace Slang
             info.facets = mergedFacets;
             return info;
         }
+        else if (auto eachType = as<EachType>(type))
+        {
+            auto elementInheritanceInfo = getInheritanceInfo(eachType->getElementType());
+            SemanticsVisitor visitor(this);
+            auto directFacet = new(arena) Facet::Impl(
+                Facet::Kind::Type,
+                Facet::Directness::Self,
+                DeclRef<Decl>(),
+                type,
+                visitor.createTypeEqualityWitness(type));
+            Facet tail = directFacet;
+            for (auto facet : elementInheritanceInfo.facets)
+            {
+                if (facet->directness == Facet::Directness::Direct)
+                {
+                    auto eachFacet = new(arena) Facet::Impl(
+                        Facet::Kind::Type,
+                        Facet::Directness::Direct,
+                        facet->origin.declRef,
+                        facet->origin.type,
+                        astBuilder->getEachSubtypeWitness(type, facet->subtypeWitness->getSup(), facet->subtypeWitness));
+                    tail->next = eachFacet;
+                    tail = eachFacet;
+                }
+            }
+            InheritanceInfo info;
+            info.facets = FacetList(directFacet);
+            return info;
+        }
         else
         {
             // As a fallback, any type not covered by the above cases will
-- 
cgit v1.2.3