Make interface types non c-style in Slang2026. (#7260)

* Make interface types non c-style.

* Make Optional<T> work with autodiff and existential types.

* Fix.

* patch behind slang 2026.

* Fix warnings.

* cleanup.

* Fix tests.

* Fix.

* Fix com interface lowering.

* Add comment to test.

* regenerate command line reference

* Add test for passing `none` to autodiff function.

* Fix recording of `getDynamicObjectRTTIBytes`.

* Fix nested Optional types.

---------

Co-authored-by: slangbot <186143334+slangbot@users.noreply.github.com>

1 files changed, 23 insertions, 23 deletions

diff --git a/source/slang/slang-emit.cpp b/source/slang/slang-emit.cpp
index a4362b912..20459c722 100644
--- a/source/slang/slang-emit.cpp
+++ b/source/slang/slang-emit.cpp
@@ -778,9 +778,6 @@ Result linkAndOptimizeIR(
         break;
     }
 
-    if (requiredLoweringPassSet.optionalType)
-        lowerOptionalType(irModule, sink);
-
     switch (target)
     {
     case CodeGenTarget::CUDASource:
@@ -792,20 +789,6 @@ Result linkAndOptimizeIR(
         break;
     }
 
-    switch (target)
-    {
-    case CodeGenTarget::CPPSource:
-    case CodeGenTarget::HostCPPSource:
-        {
-            lowerComInterfaces(irModule, artifactDesc.style, sink);
-            generateDllImportFuncs(codeGenContext->getTargetProgram(), irModule, sink);
-            generateDllExportFuncs(irModule, sink);
-            break;
-        }
-    default:
-        break;
-    }
-
 #if 0
     dumpIRIfEnabled(codeGenContext, irModule, "UNIONS DESUGARED");
 #endif
@@ -947,12 +930,6 @@ Result linkAndOptimizeIR(
             break;
     }
 
-    // Lower `Result<T,E>` types into ordinary struct types. This must happen
-    // after specialization, since otherwise incompatible copies of the lowered
-    // result structure are generated.
-    if (requiredLoweringPassSet.resultType)
-        lowerResultType(irModule, sink);
-
     // Report checkpointing information
     if (codeGenContext->shouldReportCheckpointIntermediates())
     {
@@ -978,6 +955,29 @@ Result linkAndOptimizeIR(
 
     finalizeSpecialization(irModule);
 
+    // Lower `Result<T,E>` types into ordinary struct types. This must happen
+    // after specialization, since otherwise incompatible copies of the lowered
+    // result structure are generated.
+    if (requiredLoweringPassSet.resultType)
+        lowerResultType(irModule, sink);
+
+    if (requiredLoweringPassSet.optionalType)
+        lowerOptionalType(irModule, sink);
+
+    switch (target)
+    {
+    case CodeGenTarget::CPPSource:
+    case CodeGenTarget::HostCPPSource:
+        {
+            lowerComInterfaces(irModule, artifactDesc.style, sink);
+            generateDllImportFuncs(codeGenContext->getTargetProgram(), irModule, sink);
+            generateDllExportFuncs(irModule, sink);
+            break;
+        }
+    default:
+        break;
+    }
+
     requiredLoweringPassSet = {};
     calcRequiredLoweringPassSet(requiredLoweringPassSet, codeGenContext, irModule->getModuleInst());