3 files changed, 57 insertions, 3 deletions
diff --git a/source/slang/slang-check-decl.cpp b/source/slang/slang-check-decl.cpp
index e94a3eb10..e2af70fa9 100644
--- a/source/slang/slang-check-decl.cpp
+++ b/source/slang/slang-check-decl.cpp
@@ -90,6 +90,10 @@ struct SemanticsDeclAttributesVisitor : public SemanticsDeclVisitorBase,
     void checkPrimalSubstituteOfAttribute(
         FunctionDeclBase* funcDecl,
         PrimalSubstituteOfAttribute* attr);
+
+    void checkVarDeclCommon(VarDeclBase* varDecl);
+
+    void visitVarDecl(VarDecl* varDecl) { checkVarDeclCommon(varDecl); }
 };
 
 struct SemanticsDeclHeaderVisitor : public SemanticsDeclVisitorBase,
@@ -11712,6 +11716,43 @@ bool tryCheckDerivativeOfAttributeImpl(
     return tempSink.getErrorCount() == 0;
 }
 
+void SemanticsDeclAttributesVisitor::checkVarDeclCommon(VarDeclBase* varDecl)
+{
+    bool hasSpecConstAttr = false;
+    bool hasPushConstAttr = false;
+    for (auto modifier : varDecl->modifiers)
+    {
+        if (as<SpecializationConstantAttribute>(modifier) || as<VkConstantIdAttribute>(modifier))
+        {
+            // Specialization constant.
+            // Check that type is basic type.
+            if (!as<BasicExpressionType>(varDecl->getType()) && !as<ErrorType>(varDecl->getType()))
+            {
+                getSink()->diagnose(modifier, Diagnostics::specializationConstantMustBeScalar);
+            }
+            hasSpecConstAttr = true;
+        }
+        else if (as<PushConstantAttribute>(modifier))
+        {
+            hasPushConstAttr = true;
+        }
+    }
+    if (hasSpecConstAttr && hasPushConstAttr)
+    {
+        getSink()->diagnose(
+            varDecl,
+            Diagnostics::variableCannotBePushAndSpecializationConstant,
+            varDecl->getName());
+    }
+    if (hasSpecConstAttr || hasPushConstAttr)
+    {
+        if (varDecl->findModifier<HLSLStaticModifier>())
+        {
+            getSink()->diagnose(varDecl, Diagnostics::pushOrSpecializationConstantCannotBeStatic);
+        }
+    }
+}
+
 void SemanticsDeclAttributesVisitor::checkForwardDerivativeOfAttribute(
     FunctionDeclBase* funcDecl,
     ForwardDerivativeOfAttribute* attr)
diff --git a/source/slang/slang-diagnostic-defs.h b/source/slang/slang-diagnostic-defs.h
index d6409e42e..305013f43 100644
--- a/source/slang/slang-diagnostic-defs.h
+++ b/source/slang/slang-diagnostic-defs.h
@@ -1213,8 +1213,21 @@ DIAGNOSTIC(
     Error,
     unrecognizedGLSLLayoutQualifierOrRequiresAssignment,
     "GLSL layout qualifier is unrecognized or requires assignment")
-
-
+DIAGNOSTIC(
+    31218,
+    Error,
+    specializationConstantMustBeScalar,
+    "specialization constant must be a scalar.")
+DIAGNOSTIC(
+    31219,
+    Error,
+    pushOrSpecializationConstantCannotBeStatic,
+    "push or specialization constants cannot be 'static'.")
+DIAGNOSTIC(
+    31220,
+    Error,
+    variableCannotBePushAndSpecializationConstant,
+    "'$0' cannot be a push constant and a specialization constant at the same time")
 // Enums
 
 DIAGNOSTIC(32000, Error, invalidEnumTagType, "invalid tag type for 'enum': '$0'")
diff --git a/source/slang/slang-parameter-binding.cpp b/source/slang/slang-parameter-binding.cpp
index c232d0aee..7fb719053 100644
--- a/source/slang/slang-parameter-binding.cpp
+++ b/source/slang/slang-parameter-binding.cpp
@@ -3858,7 +3858,7 @@ static bool _calcNeedsDefaultSpace(SharedParameterBindingContext& sharedContext)
             {
             default:
                 break;
-
+            case LayoutResourceKind::PushConstantBuffer:
             case LayoutResourceKind::RegisterSpace:
             case LayoutResourceKind::SubElementRegisterSpace:
             case LayoutResourceKind::VaryingInput: