Allow multiple _AttributeTargets for attribute declaration (#4087)

The syntax like:
[__AttributeUsage(_AttributeTargets.Var)]
[__AttributeUsage(_AttributeTargets.Param)]
struct DefaultValueAttribute
{
    int iParam;
};

is allowed.

For user-defined attribute, we can specify more attribute targets on the
attribute declaration. So one attribute can be used in more than one
situations.

1 files changed, 23 insertions, 7 deletions

diff --git a/tests/reflection/attribute.slang b/tests/reflection/attribute.slang
index 864aa5896..e0739643c 100644
--- a/tests/reflection/attribute.slang
+++ b/tests/reflection/attribute.slang
@@ -10,14 +10,10 @@ struct MyStructAttribute
     int iParam;
     float fParam;
 };
-[__AttributeUsage(_AttributeTargets.Var)]
-struct DefaultValueAttribute
-{
-    int iParam;
-};
 
+[__AttributeUsage(_AttributeTargets.Var)]
 [__AttributeUsage(_AttributeTargets.Param)]
-struct DefaultFuncParamAttribute
+struct DefaultValueAttribute
 {
     int iParam;
 };
@@ -43,9 +39,29 @@ ParameterBlock<B> param2;
 
 [DefaultValue(2)] int globalInt;
 
+[__AttributeUsage(_AttributeTargets.Struct)]
+[__AttributeUsage(_AttributeTargets.Var)]
+[__AttributeUsage(_AttributeTargets.Param)]
+struct StructVarParamAttribute
+{
+    int iParam;
+};
+
+[StructVarParam(0)]
+struct D
+{
+    int a;
+};
+
+D param3;
+
+[StructVarParam(1)] int globalInt2;
+
+
 [numthreads(1, 1, 1)]
 void main(
     uint3 dispatchThreadID : SV_DispatchThreadID,
-    [DefaultFuncParam(3)] float a)
+    [DefaultValue(3)] float a,
+    [StructVarParam(2)] float b)
 {
 }