Fix segfault on arrays of structs containing parameter blocks (#8555)

Closes https://github.com/shader-slang/slang/issues/8154 However there
is further design work to do on implementing the "NonAddressableType"
suggestion

5 files changed, 41 insertions, 6 deletions

diff --git a/source/slang/slang-ast-decl.cpp b/source/slang/slang-ast-decl.cpp
index 1e2d11600..817230984 100644
--- a/source/slang/slang-ast-decl.cpp
+++ b/source/slang/slang-ast-decl.cpp
@@ -493,7 +493,7 @@ InterfaceDecl* ThisTypeConstraintDecl::getInterfaceDecl()
 
 void AggTypeDecl::addTag(TypeTag tag)
 {
-    typeTags = (TypeTag)((int)tag | (int)tag);
+    typeTags = (TypeTag)((int)typeTags | (int)tag);
 }
 
 bool AggTypeDecl::hasTag(TypeTag tag)
diff --git a/source/slang/slang-ast-decl.h b/source/slang/slang-ast-decl.h
index 1a850da0d..0bda6fc79 100644
--- a/source/slang/slang-ast-decl.h
+++ b/source/slang/slang-ast-decl.h
@@ -377,6 +377,7 @@ enum class TypeTag
     Incomplete = 2,
     LinkTimeSized = 4,
     Opaque = 8,
+    NonAddressable = 16,
 };
 
 // Declaration of a type that represents some sort of aggregate
diff --git a/source/slang/slang-check-conformance.cpp b/source/slang/slang-check-conformance.cpp
index ba1b8ea55..40ab66e95 100644
--- a/source/slang/slang-check-conformance.cpp
+++ b/source/slang/slang-check-conformance.cpp
@@ -348,7 +348,11 @@ TypeTag SemanticsVisitor::getTypeTags(Type* type)
             typeTag = (TypeTag)((int)typeTag | (int)TypeTag::LinkTimeSized);
         }
         if (!sized)
-            typeTag = (TypeTag)((int)typeTag | (int)TypeTag::Unsized);
+        {
+            // Unbounded arrays are both Unsized and NonAddressable
+            typeTag =
+                (TypeTag)((int)typeTag | (int)TypeTag::Unsized | (int)TypeTag::NonAddressable);
+        }
 
         return typeTag;
     }
@@ -356,6 +360,11 @@ TypeTag SemanticsVisitor::getTypeTags(Type* type)
     {
         return getTypeTags(modifiedType->getBase());
     }
+    if (as<ParameterBlockType>(type))
+    {
+        // ParameterBlock types are non-addressable
+        return TypeTag::NonAddressable;
+    }
     if (auto parameterGroupType = as<UniformParameterGroupType>(type))
     {
         auto elementTags = getTypeTags(parameterGroupType->getElementType());
@@ -372,7 +381,9 @@ TypeTag SemanticsVisitor::getTypeTags(Type* type)
     else if (auto declRefType = as<DeclRefType>(type))
     {
         if (auto aggTypeDecl = as<AggTypeDecl>(declRefType->getDeclRef()))
+        {
             return aggTypeDecl.getDecl()->typeTags;
+        }
     }
     return TypeTag::None;
 }
diff --git a/source/slang/slang-check-decl.cpp b/source/slang/slang-check-decl.cpp
index 867c1daad..1ba8c62f3 100644
--- a/source/slang/slang-check-decl.cpp
+++ b/source/slang/slang-check-decl.cpp
@@ -2703,6 +2703,9 @@ void SemanticsDeclBodyVisitor::checkVarDeclCommon(VarDeclBase* varDecl)
 {
     DiagnoseIsAllowedInitExpr(varDecl, getSink());
 
+    // Check for arrays of non-addressable types
+    validateArrayElementTypeForVariable(varDecl);
+
     // if zero initialize is true, set everything to a default
     if (getOptionSet().hasOption(CompilerOptionName::ZeroInitialize) && !varDecl->initExpr &&
         as<VarDecl>(varDecl))
@@ -2840,6 +2843,7 @@ void SemanticsDeclBodyVisitor::checkVarDeclCommon(VarDeclBase* varDecl)
     }
 
     TypeTag varTypeTags = getTypeTags(varDecl->getType());
+
     auto parentDecl = as<AggTypeDecl>(getParentDecl(varDecl));
     if (parentDecl)
     {
@@ -10389,9 +10393,12 @@ void SemanticsVisitor::validateArrayElementTypeForVariable(VarDeclBase* varDecl)
         return;
 
     const auto elementType = arrayType->getElementType();
-    if (as<ParameterBlockType>(elementType))
+
+    // Check if the element type has the NonAddressable tag
+    TypeTag elementTags = getTypeTags(elementType);
+    if ((int)elementTags & (int)TypeTag::NonAddressable)
     {
-        getSink()->diagnose(varDecl, Diagnostics::disallowedArrayOfParameterBlock);
+        getSink()->diagnose(varDecl, Diagnostics::disallowedArrayOfNonAddressableType, elementType);
         return;
     }
 }
@@ -14738,6 +14745,16 @@ void validateStructuredBufferElementType(SemanticsVisitor* visitor, VarDeclBase*
             Diagnostics::recursiveTypesFoundInStructuredBuffer,
             elementType);
     }
+
+    // Check if the element type is NonAddressable
+    TypeTag elementTags = visitor->getTypeTags(elementType);
+    if ((int)elementTags & (int)TypeTag::NonAddressable)
+    {
+        visitor->getSink()->diagnose(
+            varDecl->loc,
+            Diagnostics::nonAddressableTypeInStructuredBuffer,
+            elementType);
+    }
 }
 
 void diagnoseMissingCapabilityProvenance(
diff --git a/source/slang/slang-diagnostic-defs.h b/source/slang/slang-diagnostic-defs.h
index 840192a50..20d15a2ef 100644
--- a/source/slang/slang-diagnostic-defs.h
+++ b/source/slang/slang-diagnostic-defs.h
@@ -661,8 +661,14 @@ DIAGNOSTIC(30025, Error, invalidArraySize, "array size must be non-negative.")
 DIAGNOSTIC(
     30027,
     Error,
-    disallowedArrayOfParameterBlock,
-    "Arrays of ParameterBlock are not allowed")
+    disallowedArrayOfNonAddressableType,
+    "Arrays of non-addressable type '$0' are not allowed")
+
+DIAGNOSTIC(
+    30028,
+    Error,
+    nonAddressableTypeInStructuredBuffer,
+    "'$0' is non-addressable and cannot be used in StructuredBuffer")
 DIAGNOSTIC(
     30029,
     Error,