Fix `getInheritanceInfo` for `ExtractExistentialType`. (#5971)

4 files changed, 26 insertions, 23 deletions

diff --git a/source/slang/slang-check-impl.h b/source/slang/slang-check-impl.h
index f464f9298..300596caa 100644
--- a/source/slang/slang-check-impl.h
+++ b/source/slang/slang-check-impl.h
@@ -789,12 +789,12 @@ private:
 
     InheritanceInfo _getInheritanceInfo(
         DeclRef<Decl> declRef,
-        DeclRefType* correspondingType,
+        Type* selfType,
         InheritanceCircularityInfo* circularityInfo);
     InheritanceInfo _calcInheritanceInfo(Type* type, InheritanceCircularityInfo* circularityInfo);
     InheritanceInfo _calcInheritanceInfo(
         DeclRef<Decl> declRef,
-        DeclRefType* correspondingType,
+        Type* selfType,
         InheritanceCircularityInfo* circularityInfo);
 
     void getDependentGenericParentImpl(DeclRef<GenericDecl>& genericParent, DeclRef<Decl> declRef);
diff --git a/source/slang/slang-check-inheritance.cpp b/source/slang/slang-check-inheritance.cpp
index 4b0ec0f55..f774aae38 100644
--- a/source/slang/slang-check-inheritance.cpp
+++ b/source/slang/slang-check-inheritance.cpp
@@ -76,7 +76,7 @@ bool SharedSemanticsContext::_checkForCircularityInExtensionTargetType(
 
 InheritanceInfo SharedSemanticsContext::_getInheritanceInfo(
     DeclRef<Decl> declRef,
-    DeclRefType* declRefType,
+    Type* selfType,
     InheritanceCircularityInfo* circularityInfo)
 {
     // Just as with `Type`s, we cache and re-use the inheritance
@@ -95,7 +95,7 @@ InheritanceInfo SharedSemanticsContext::_getInheritanceInfo(
     //
     m_mapDeclRefToInheritanceInfo[declRef] = InheritanceInfo();
 
-    auto info = _calcInheritanceInfo(declRef, declRefType, circularityInfo);
+    auto info = _calcInheritanceInfo(declRef, selfType, circularityInfo);
     m_mapDeclRefToInheritanceInfo[declRef] = info;
 
     getSession()->m_typeDictionarySize = Math::Max(
@@ -154,7 +154,7 @@ DeclRef<GenericDecl> SharedSemanticsContext::getDependentGenericParent(DeclRef<D
 
 InheritanceInfo SharedSemanticsContext::_calcInheritanceInfo(
     DeclRef<Decl> declRef,
-    DeclRefType* declRefType,
+    Type* selfType,
     InheritanceCircularityInfo* circularityInfo)
 {
     // This method is the main engine for computing linearized inheritance
@@ -200,14 +200,6 @@ InheritanceInfo SharedSemanticsContext::_calcInheritanceInfo(
     //
     FacetList::Builder allFacets;
 
-    // It is possible that `declRef` is itself a type declaration,
-    // in which case `declRefType` will be the coresponding type.
-    // However, if `declRef` is an `extension` declaration, we
-    // will extract the type that the extension applies to, so
-    // that we can have a consistent "self type" to represent
-    // the type that is at the root of the inheritance list.
-    //
-    Type* selfType = declRefType;
     Facet::Kind selfFacetKind = Facet::Kind::Type;
 
     auto astBuilder = _getASTBuilder();
@@ -1043,6 +1035,13 @@ InheritanceInfo SharedSemanticsContext::_calcInheritanceInfo(
         //
         return _getInheritanceInfo(declRefType->getDeclRef(), declRefType, circularityInfo);
     }
+    else if (auto extractExistentialType = as<ExtractExistentialType>(type))
+    {
+        return _getInheritanceInfo(
+            extractExistentialType->getThisTypeDeclRef(),
+            extractExistentialType,
+            circularityInfo);
+    }
     else if (auto conjunctionType = as<AndType>(type))
     {
         // In this case, we have a type of the form `L & R`,
diff --git a/source/slang/slang-ir-legalize-types.cpp b/source/slang/slang-ir-legalize-types.cpp
index 9154277f5..962514b08 100644
--- a/source/slang/slang-ir-legalize-types.cpp
+++ b/source/slang/slang-ir-legalize-types.cpp
@@ -837,7 +837,7 @@ static LegalVal legalizeDebugVar(
     case LegalType::Flavor::simple:
         {
             auto legalVal = context->builder->emitDebugVar(
-                type.getSimple(),
+                tryGetPointedToType(context->builder, type.getSimple()),
                 originalInst->getSource(),
                 originalInst->getLine(),
                 originalInst->getCol(),
@@ -887,7 +887,7 @@ static LegalVal legalizeDebugValue(
         {
             auto ordinaryVal = legalizeDebugValue(
                 context,
-                debugVar,
+                debugVar.getPair()->ordinaryVal,
                 debugValue.getPair()->ordinaryVal,
                 originalInst);
             return ordinaryVal;
diff --git a/source/slang/slang-syntax.cpp b/source/slang/slang-syntax.cpp
index 5dc6ca695..6fdd5088a 100644
--- a/source/slang/slang-syntax.cpp
+++ b/source/slang/slang-syntax.cpp
@@ -701,11 +701,18 @@ Type* DeclRefType::create(ASTBuilder* astBuilder, DeclRef<Decl> declRef)
         }
         return declRefType;
     }
-    else if (as<ThisTypeDecl>(declRef.getDecl()) && as<DirectDeclRef>(declRef.declRefBase))
+    else if (as<ThisTypeDecl>(declRef.getDecl()))
     {
-        declRef = createDefaultSubstitutionsIfNeeded(astBuilder, nullptr, declRef);
+        if (as<DirectDeclRef>(declRef.declRefBase))
+        {
+            declRef = createDefaultSubstitutionsIfNeeded(astBuilder, nullptr, declRef);
 
-        return astBuilder->getOrCreate<ThisType>(declRef.declRefBase);
+            return astBuilder->getOrCreate<ThisType>(declRef.declRefBase);
+        }
+        else if (auto lookupDeclRef = as<LookupDeclRef>(declRef.declRefBase))
+        {
+            return lookupDeclRef->getWitness()->getSub();
+        }
     }
     else if (auto typedefDecl = as<TypeDefDecl>(declRef.getDecl()))
     {
@@ -714,12 +721,9 @@ Type* DeclRefType::create(ASTBuilder* astBuilder, DeclRef<Decl> declRef)
                 typedefDecl->type.type->substitute(astBuilder, SubstitutionSet(declRef)));
         return astBuilder->getErrorType();
     }
-    else
-    {
-        declRef = createDefaultSubstitutionsIfNeeded(astBuilder, nullptr, declRef);
 
-        return astBuilder->getOrCreate<DeclRefType>(declRef.declRefBase);
-    }
+    declRef = createDefaultSubstitutionsIfNeeded(astBuilder, nullptr, declRef);
+    return astBuilder->getOrCreate<DeclRefType>(declRef.declRefBase);
 }
 
 //