Allow `class` to implement COM interface, [DLLExport] (#2338)

* Allow `class` to implement COM interface, [DLLExport]

* Fix [COM] usage in tests and examples with UUIDs.

Co-authored-by: Yong He <yhe@nvidia.com>

1 files changed, 6 insertions, 1 deletions

diff --git a/source/slang/slang-ir-lower-existential.cpp b/source/slang/slang-ir-lower-existential.cpp
index b0d9e6f2f..cfdacc7ac 100644
--- a/source/slang/slang-ir-lower-existential.cpp
+++ b/source/slang/slang-ir-lower-existential.cpp
@@ -24,6 +24,8 @@ namespace Slang
             auto valueType = sharedContext->lowerType(builder, value->getDataType());
             auto witnessTableType = cast<IRWitnessTableTypeBase>(inst->getWitnessTable()->getDataType());
             auto interfaceType = witnessTableType->getConformanceType();
+            if (interfaceType->findDecoration<IRComInterfaceDecoration>())
+                return;
             auto witnessTableIdType = builder->getWitnessTableIDType((IRType*)interfaceType);
             auto anyValueSize = sharedContext->getInterfaceAnyValueSize(interfaceType, inst->sourceLoc);
             auto anyValueType = builder->getAnyValueType(anyValueSize);
@@ -139,7 +141,10 @@ namespace Slang
             IRBuilder builderStorage(sharedContext->sharedBuilderStorage);
             auto builder = &builderStorage;
             builder->setInsertBefore(inst);
-
+            if (inst->getDataType()->getOp() == kIROp_ClassType)
+            {
+                return;
+            }
             // A value of interface will lower as a tuple, and
             // the third element of that tuple represents the
             // concrete value that was put into the existential.