Fix up emission of shader parameter semantics when using IR (#226)

* Fix up emission of shader parameter semantics when using IR

- Make sure to propagate entry point parameter layouts down to IR parameters when doing the initial cloning to form target-specific IR

- When layout information is present on an IR node, prefer to use that over the original high-level declaration for outputting semantics in final HLSL

- Fix up test runner to generate `.actual` files when running compute tests, in cases where the `render-test` application errors out (e.g., because of a Slang compilation error)

- Add a first test of generics functionality, to show that they generate valid code through the IR
  - Right now this test is *not* using any "interesting" operations on the type parameter, so this is not a test that can confirm that interface constraints work

* fixup: skip compute tests when running on Linux

1 files changed, 31 insertions, 0 deletions

diff --git a/source/slang/emit.cpp b/source/slang/emit.cpp
index 971f0345b..1b5db065f 100644
--- a/source/slang/emit.cpp
+++ b/source/slang/emit.cpp
@@ -5090,6 +5090,37 @@ emitDeclImpl(decl, nullptr);
         EmitContext*    context,
         IRValue*         inst)
     {
+        // Don't emit semantics if we aren't translating down to HLSL
+        switch (context->shared->target)
+        {
+        case CodeGenTarget::HLSL:
+            break;
+
+        default:
+            return;
+        }
+
+        if(auto layoutDecoration = inst->findDecoration<IRLayoutDecoration>())
+        {
+            if(auto varLayout = layoutDecoration->layout.As<VarLayout>())
+            {
+                if(varLayout->flags & VarLayoutFlag::HasSemantic)
+                {
+                    Emit(" : ");
+                    emit(varLayout->semanticName);
+                    if(varLayout->semanticIndex)
+                    {
+                        Emit(varLayout->semanticIndex);
+                    }
+
+                    return;
+                }
+            }
+        }
+
+        // TODO(tfoley): should we ever need to use the high-level declaration
+        // for this? It seems like the wrong approach...
+
         auto decoration = inst->findDecoration<IRHighLevelDeclDecoration>();
         if( decoration )
         {