[HLSL] get inout/out ABI for array parameters working (#111047)

Get inout/out parameters working for HLSL Arrays.
Utilizes the fix from #109323, and corrects the assignment behavior
slightly to allow for Non-LValues on the RHS.
Closes #106917

---------

Co-authored-by: Chris B <beanz@abolishcrlf.org>

1 files changed, 9 insertions, 0 deletions

diff --git a/clang/lib/Sema/Sema.cpp b/clang/lib/Sema/Sema.cpp
index 942e7ec..d651751 100644
--- a/clang/lib/Sema/Sema.cpp
+++ b/clang/lib/Sema/Sema.cpp
@@ -723,6 +723,15 @@ ExprResult Sema::ImpCastExprToType(Expr *E, QualType Ty,
   QualType ExprTy = Context.getCanonicalType(E->getType());
   QualType TypeTy = Context.getCanonicalType(Ty);
 
+  // This cast is used in place of a regular LValue to RValue cast for
+  // HLSL Array Parameter Types. It needs to be emitted even if
+  // ExprTy == TypeTy, except if E is an HLSLOutArgExpr
+  // Emitting a cast in that case will prevent HLSLOutArgExpr from
+  // being handled properly in EmitCallArg
+  if (Kind == CK_HLSLArrayRValue && !isa<HLSLOutArgExpr>(E))
+    return ImplicitCastExpr::Create(Context, Ty, Kind, E, BasePath, VK,
+                                    CurFPFeatureOverrides());
+
   if (ExprTy == TypeTy)
     return E;