Fix warning when use implicit launch type. (#6837) (#6841)

By default, the launch type should be set to ‘Broadcast’ when diagnosing
barriers. However, the current behavior sets the default launch type to
‘Invalid,’ resulting in warnings when the launch type is not explicitly
specified as an attribute.

To address this issue, we’ll adjust the default setting to ‘Broadcast’
and thereby resolve the problem.

Fixes #6836

---------

Co-authored-by: Damyan Pepper <damyanp@microsoft.com>
(cherry picked from commit ef043e9)

tools/clang/lib/Sema/SemaHLSLDiagnoseTU.cpp

@@ -529,10 +529,13 @@ void hlsl::DiagnoseTranslationUnit(clang::Sema *self) {
       // attribute.
       if (const auto *Attr = FDecl->getAttr<clang::HLSLShaderAttr>())
         EntrySK = ShaderModel::KindFromFullName(Attr->getStage());
-      if (EntrySK == DXIL::ShaderKind::Node)
+      if (EntrySK == DXIL::ShaderKind::Node) {
         if (const auto *pAttr = FDecl->getAttr<HLSLNodeLaunchAttr>())
           NodeLaunchTy =
               ShaderModel::NodeLaunchTypeFromName(pAttr->getLaunchType());
+        else
+          NodeLaunchTy = DXIL::NodeLaunchType::Broadcasting;
+      }
     }
     // Visit all visited functions in call graph to collect illegal intrinsic
     // calls.

tools/clang/test/SemaHLSL/hlsl/intrinsics/barrier/barrier-node-errors.hlsl

@@ -192,3 +192,15 @@ void node02(RWThreadNodeInputRecord<RECORD> input,
   Barrier(threadRec, DEVICE_SCOPE);
   threadRec.OutputComplete();
 }
+
+// Default launch type is broadcasting which has a visible group.
+// It is OK to use GROUP_SYNC or GROUP_SCOPE.
+[Shader("node")]
+[NumThreads(64,1,1)]
+[NodeDispatchGrid(1, 1, 1)]
+void defaultBroadcastingLaunch(RWDispatchNodeInputRecord<RECORD> input,
+            [MaxRecords(11)] NodeOutput<RECORD> output) {
+  Barrier(UAV_MEMORY, GROUP_SYNC);
+  Barrier(UAV_MEMORY, GROUP_SCOPE);
+  Barrier(UAV_MEMORY, GROUP_SCOPE|GROUP_SYNC);
+}