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, 39 insertions, 0 deletions

diff --git a/tests/bugs/enum-different-types.slang b/tests/bugs/enum-different-types.slang
new file mode 100644
index 000000000..93deffdd8
--- /dev/null
+++ b/tests/bugs/enum-different-types.slang
@@ -0,0 +1,39 @@
+//TEST:SIMPLE(filecheck=CHECK):-target hlsl -stage vertex -entry main
+
+// Test enum without explicit tag type (should default to int)
+public enum SimpleEnum {
+    value1,
+    value2,
+    value3
+}
+
+// Test enum with different tag types
+public enum ByteEnum : uint8_t {
+    a, b, c
+}
+
+public enum IntEnum : int {
+    x = -1, y = 0, z = 1
+}
+
+struct VertexInput {
+    float3 position : POSITION_ATTR;
+};
+
+public struct VertexOutput {
+    float4 position : SV_Position;
+    SimpleEnum simple : TEXCOORD0;
+    IntEnum intVal : TEXCOORD1;
+}
+
+[shader("vertex")]
+VertexOutput main(in VertexInput input) {
+    VertexOutput output;
+    output.position = float4(0);
+    output.simple = SimpleEnum.value1;
+    output.intVal = IntEnum.x;
+    return output;
+}
+
+//CHECK: simple_0 : TEXCOORD0
+//CHECK: intVal_0 : TEXCOORD1
\ No newline at end of file