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, 72 insertions, 0 deletions

diff --git a/source/slang/slang-ir-dll-export.cpp b/source/slang/slang-ir-dll-export.cpp
new file mode 100644
index 000000000..a8b464b43
--- /dev/null
+++ b/source/slang/slang-ir-dll-export.cpp
@@ -0,0 +1,72 @@
+// slang-ir-dll-export.cpp
+#include "slang-ir-dll-export.h"
+
+#include "slang-ir.h"
+#include "slang-ir-insts.h"
+#include "slang-ir-marshal-native-call.h"
+
+namespace Slang
+{
+
+struct DllExportContext
+{
+    IRModule* module;
+    DiagnosticSink* diagnosticSink;
+
+    SharedIRBuilder sharedBuilder;
+
+    void processFunc(IRFunc* func, IRDllExportDecoration* dllExportDecoration)
+    {
+        NativeCallMarshallingContext marshalContext;
+        marshalContext.diagnosticSink = diagnosticSink;
+        IRBuilder builder(sharedBuilder);
+        auto wrapper = marshalContext.generateDLLExportWrapperFunc(builder, func);
+        dllExportDecoration->removeFromParent();
+        dllExportDecoration->insertAtStart(wrapper);
+        builder.addNameHintDecoration(wrapper, dllExportDecoration->getFunctionName());
+        builder.addExternCppDecoration(wrapper, dllExportDecoration->getFunctionName());
+        builder.addPublicDecoration(wrapper);
+        builder.addKeepAliveDecoration(wrapper);
+        builder.addHLSLExportDecoration(wrapper);
+        if (auto oldPublicDecoration = func->findDecoration<IRPublicDecoration>())
+        {
+            oldPublicDecoration->removeFromParent();
+        }
+    }
+
+    void processModule()
+    {
+        struct Candidate { IRFunc* func; IRDllExportDecoration* exportDecoration; };
+        List<Candidate> candidates;
+        for (auto childFunc : module->getGlobalInsts())
+        {
+            switch(childFunc->getOp())
+            {
+            case kIROp_Func:
+                if (auto dllExportDecoration = childFunc->findDecoration<IRDllExportDecoration>())
+                {
+                    candidates.add(Candidate{ as<IRFunc>(childFunc), dllExportDecoration });
+                }
+                break;
+            default:
+                break;
+            }
+        }
+
+        for (auto candidate : candidates)
+        {
+            processFunc(candidate.func, candidate.exportDecoration);
+        }
+    }
+};
+
+void generateDllExportFuncs(IRModule* module, DiagnosticSink* sink)
+{
+    DllExportContext context;
+    context.module = module;
+    context.diagnosticSink = sink;
+    context.sharedBuilder.init(module);
+    return context.processModule();
+}
+
+}