Add diagnostic for calling non-bwd-diff func from bwd-diff func. (#2602)

1 files changed, 7 insertions, 1 deletions

diff --git a/source/slang/slang-check-impl.h b/source/slang/slang-check-impl.h
index fb47a38c1..6099febb5 100644
--- a/source/slang/slang-check-impl.h
+++ b/source/slang/slang-check-impl.h
@@ -11,7 +11,12 @@
 
 namespace Slang
 {
-    
+    enum class FunctionDifferentiableLevel
+    {
+        None,
+        Forward,
+        Backward
+    };
         /// Should the given `decl` be treated as a static rather than instance declaration?
     bool isEffectivelyStatic(
         Decl*           decl);
@@ -292,6 +297,7 @@ namespace Slang
 
         bool isDifferentiableFunc(FunctionDeclBase* func);
         bool isBackwardDifferentiableFunc(FunctionDeclBase* func);
+        FunctionDifferentiableLevel getFuncDifferentiableLevel(FunctionDeclBase* func);
 
     private:
             /// Mapping from type declarations to the known extensiosn that apply to them