MSL: Emit interface block members of array length 1 as arrays instead of scalars.

Test for array presence using is_array() instead of element count.
Add shaders-msl/vert/interface-block-single-element-array.vert regression test.

Fixes a regression error introduced in 3d4daab.

1 files changed, 79 insertions, 0 deletions

diff --git a/reference/opt/shaders-msl/vert/interface-block-single-element-array.vert b/reference/opt/shaders-msl/vert/interface-block-single-element-array.vert
new file mode 100644
index 00000000..6858db73
--- /dev/null
+++ b/reference/opt/shaders-msl/vert/interface-block-single-element-array.vert
@@ -0,0 +1,79 @@
+#pragma clang diagnostic ignored "-Wmissing-prototypes"
+#pragma clang diagnostic ignored "-Wmissing-braces"
+
+#include <metal_stdlib>
+#include <simd/simd.h>
+
+using namespace metal;
+
+template<typename T, size_t Num>
+struct spvUnsafeArray
+{
+    T elements[Num ? Num : 1];
+    
+    thread T& operator [] (size_t pos) thread
+    {
+        return elements[pos];
+    }
+    constexpr const thread T& operator [] (size_t pos) const thread
+    {
+        return elements[pos];
+    }
+    
+    device T& operator [] (size_t pos) device
+    {
+        return elements[pos];
+    }
+    constexpr const device T& operator [] (size_t pos) const device
+    {
+        return elements[pos];
+    }
+    
+    constexpr const constant T& operator [] (size_t pos) const constant
+    {
+        return elements[pos];
+    }
+    
+    threadgroup T& operator [] (size_t pos) threadgroup
+    {
+        return elements[pos];
+    }
+    constexpr const threadgroup T& operator [] (size_t pos) const threadgroup
+    {
+        return elements[pos];
+    }
+};
+
+struct TDPickVertex
+{
+    float4 c;
+    spvUnsafeArray<float3, 1> uv;
+};
+
+struct main0_out
+{
+    float4 oTDVert_c [[user(locn0)]];
+    float3 oTDVert_uv_0 [[user(locn1)]];
+    float4 gl_Position [[position]];
+};
+
+struct main0_in
+{
+    float3 P [[attribute(0)]];
+    float3 uv_0 [[attribute(1)]];
+};
+
+vertex main0_out main0(main0_in in [[stage_in]])
+{
+    main0_out out = {};
+    TDPickVertex oTDVert = {};
+    spvUnsafeArray<float3, 1> uv = {};
+    uv[0] = in.uv_0;
+    out.gl_Position = float4(in.P, 1.0);
+    oTDVert.uv[0] = uv[0];
+    oTDVert.c = float4(1.0);
+    out.oTDVert_c = oTDVert.c;
+    out.oTDVert_uv_0 = oTDVert.uv[0];
+    return out;
+}
+