From 14d5da916447f10bb812c3c6a199ab4ab76f61ec Mon Sep 17 00:00:00 2001
From: Ali Cheraghi <alichraghi@proton.me>
Date: Sun, 21 Jun 2026 08:49:15 +0330
Subject: [PATCH] spirv: don't put dummy `OpVariable` for non-Function pointers

This would raise a validation error when the parameter type is a non-Function opaque pointer.
e.g. an `@extern(*addrspace(.constant) const SampledImage, ...)`
---
 src/codegen/spirv/CodeGen.zig       |  3 ++-
 test/cases/image_sampling_spirv.zig | 42 +++++++++++++++++++++++++++++
 2 files changed, 44 insertions(+), 1 deletion(-)
 create mode 100644 test/cases/image_sampling_spirv.zig

diff --git a/src/codegen/spirv/CodeGen.zig b/src/codegen/spirv/CodeGen.zig
index f6c533c31aadd92f7dc52d1b3898667cf880cbfa..d60ccf8dc1fd3f2d44e2ac3017f7c904f0946bfb 100644
--- a/src/codegen/spirv/CodeGen.zig
+++ b/src/codegen/spirv/CodeGen.zig
@@ -8112,7 +8112,8 @@ fn airCall(cg: *CodeGen, inst: Air.Inst.Index, modifier: std.lang.CallModifier)
         if (!arg_ty.hasRuntimeBits(zcu)) continue;
 
         if (arg_ty.zigTypeTag(zcu) == .pointer and !arg_ty.isSlice(zcu) and
-            !arg_ty.childType(zcu).hasRuntimeBits(zcu))
+            !arg_ty.childType(zcu).hasRuntimeBits(zcu) and
+            cg.module.storageClass(arg_ty.ptrAddressSpace(zcu)) == .function)
         {
             // in logical addressing, pointer arguments to function calls
             // must be memory object declarations (OpVariable). for pointers to
diff --git a/test/cases/image_sampling_spirv.zig b/test/cases/image_sampling_spirv.zig
new file mode 100644
index 0000000000000000000000000000000000000000..030727e95c106b6b2521ab72d07bb608b58a22a8
--- /dev/null
+++ b/test/cases/image_sampling_spirv.zig
@@ -0,0 +1,42 @@
+pub const Image = @SpirvType(.{ .image = .{
+    .usage = .{ .sampled = f32 },
+    .format = .unknown,
+    .dim = .@"2d",
+    .depth = .not_depth,
+    .arrayed = false,
+    .multisampled = false,
+    .access = .unknown,
+} });
+pub const SampledImage = @SpirvType(.{ .sampled_image = Image });
+
+const image_in = @extern(*addrspace(.constant) const SampledImage, .{
+    .name = "image_in",
+    .decoration = .{ .descriptor = .{ .set = 2, .binding = 0 } },
+});
+const uv_in = @extern(*addrspace(.input) @Vector(2, f32), .{ .name = "uv", .decoration = .{ .location = 0 } });
+const color_out = @extern(*addrspace(.output) @Vector(4, f32), .{ .name = "color", .decoration = .{ .location = 0 } });
+
+export fn main() callconv(.{ .spirv_fragment = .{} }) void {
+    color_out.* = imageSample(image_in, uv_in.*);
+}
+
+fn imageSample(
+    sampled_image: *addrspace(.constant) const SampledImage,
+    uv: @Vector(2, f32),
+) @Vector(4, f32) {
+    return asm volatile (
+        \\%loaded_sampler = OpLoad %SampledImage %sampled_image
+        \\%ret            = OpImageSampleImplicitLod %Result %loaded_sampler %uv
+        : [ret] "" (-> @Vector(4, f32)),
+        : [SampledImage] "t" (SampledImage),
+          [sampled_image] "" (sampled_image),
+          [Result] "t" (@Vector(4, f32)),
+          [uv] "" (uv),
+    );
+}
+
+// compile
+// output_mode=Exe
+// backend=selfhosted
+// target=spirv32-vulkan
+// emit_bin=true
-- 
2.54.0