Fix a bug in handling explicit register space bindings (#1175)

The logic for handling explicit `space`/`set` bindings on shader parameters for parameter blocks was not correctly marking the `space`/`set` that gets grabbed as used, and as a result it was possible for another parameter block that relies on implicit assignment to end up with a conflicting space.

This change fixes the original oversight, and adds a test case to prevent against regression.

1 files changed, 18 insertions, 0 deletions

diff --git a/tests/reflection/mix-explicit-and-implicit-spaces.slang b/tests/reflection/mix-explicit-and-implicit-spaces.slang
new file mode 100644
index 000000000..52dd4321e
--- /dev/null
+++ b/tests/reflection/mix-explicit-and-implicit-spaces.slang
@@ -0,0 +1,18 @@
+// mix-explicit-and-implicit-spaces.slang
+//TEST:REFLECTION:-profile cs_5_1 -target hlsl
+
+// Ensure that correct layout/reflection is computed
+// when mixing implicit and explicit spaces for
+// parameter blocks.
+
+struct A { float x; }
+ParameterBlock<A> a : register(space0);
+
+struct B { float y; }
+ParameterBlock<B> b : register(space1);
+
+struct C { float z; }
+ParameterBlock<C> c;
+
+void main()
+{}