Bindings missing from reflection data if passed by parameter

[aclysma]

When I compile this shader and run it through spirv_reflect, I get reflection data as I expect

#version 450

layout (set = 0, binding = 1) uniform sampler smp;
layout (set = 1, binding = 3) uniform texture2D tex;

layout (location = 0) out vec4 out_color;

vec4 normal_map(
    texture2D t,
    sampler s,
    vec2 uv
) {
    // *** NOT using the parameters, just accessing tex/smp directly ***
    return texture(sampler2D(tex, smp), uv);
}

void main() {
    out_color = normal_map(tex, smp, vec2(1.0, 1.0));
}

If I use this code instead, the bindings are not in the reflection data.

#version 450

layout (set = 0, binding = 1) uniform sampler smp;
layout (set = 1, binding = 3) uniform texture2D tex;

layout (location = 0) out vec4 out_color;

vec4 normal_map(
    texture2D t,
    sampler s,
    vec2 uv
) {
    // *** Using parameters t and s instead of "global" tex/smp ***
    return texture(sampler2D(t, s), uv);
}

void main() {
    out_color = normal_map(tex, smp, vec2(1.0, 1.0));
}

I'm going through rust bindings, but this is the code I'm calling:

    let enumerated_entry_points = shader_module.enumerate_entry_points()?;
    for entry_point in enumerated_entry_points {
        for descriptor_set in &entry_point.descriptor_sets {
            for binding in &descriptor_set.bindings {
                println!("binding {} {} {}", binding.name, binding.set, binding.binding);
            }
        }
    }

Is this expected behavior? I expected that these shaders would produce identical reflection data.

[chaoticbob]

You're right, it should produce the same reflection data. My initial guess on what's happening is that there's a case where the parser can't connect the passed arguments with the parameters being referenced. Most likely a pattern it hasn't seen before. I'll have a look.

Thank you for providing the shaders for repro.

[spencer-lunarg]

moving the example from KhronosGroup/glslang#3468 here

#version 450

vec3 IBL(samplerCube env_map, sampler2D dfg_lut) {
  float r = 1;
  float lod = 1;
  vec4 env_map_sample = textureLod(env_map, vec3(r), lod);
  vec2 dfg = texture(dfg_lut, vec2(0, 0)).rg;
  return env_map_sample.xyz + vec3(dfg, 0.0);
}

layout(set = 0, binding = 0) uniform samplerCube u_ibl_view;
layout(set = 0, binding = 1) uniform sampler2D u_dfg_lut_view;
layout(location = 0) out vec4 o_color;

void main() {
  o_color = vec4(IBL(u_ibl_view, u_dfg_lut_view), 1);
}

also is not working as expected