Fix compiler crash when enum is used as vertex output data (#7915)

* Initial plan

* Initial investigation and plan for enum vertex output fix

Co-authored-by: csyonghe <2652293+csyonghe@users.noreply.github.com>

* Fix compiler crash when enum is used as vertex output data

Co-authored-by: csyonghe <2652293+csyonghe@users.noreply.github.com>

* Fix compiler crash when enum is used as vertex output data

Co-authored-by: csyonghe <2652293+csyonghe@users.noreply.github.com>

* Address reviewer feedback: use SLANG_ASSERT and improve CHECK directives

Co-authored-by: csyonghe <2652293+csyonghe@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: csyonghe <2652293+csyonghe@users.noreply.github.com>

1 files changed, 25 insertions, 0 deletions

diff --git a/tests/bugs/enum-fragment-input.slang b/tests/bugs/enum-fragment-input.slang
new file mode 100644
index 000000000..e03514467
--- /dev/null
+++ b/tests/bugs/enum-fragment-input.slang
@@ -0,0 +1,25 @@
+//TEST:SIMPLE(filecheck=CHECK):-target hlsl -stage fragment -entry main
+
+public enum VertexLayout : uint {
+    position = 0,
+    color = 1,
+    uv = 2
+}
+
+struct FragmentInput {
+    float4 position : SV_Position;
+    VertexLayout layout : TEXCOORD0;
+};
+
+struct FragmentOutput {
+    float4 color : SV_Target;
+};
+
+[shader("fragment")]
+FragmentOutput main(in FragmentInput input) {
+    FragmentOutput output;
+    output.color = float4(float(input.layout), 0, 0, 1);
+    return output;
+}
+
+//CHECK: main
\ No newline at end of file