Declaration of global uniform bool raises validation error

[rdb]

The use of "uniform bool" results in a spirv-val error:

error: line 17: If OpTypeBool is stored in conjunction with OpVariable, it can only be used with non-externally visible shader Storage Classes: Workgroup, CrossWorkgroup, Private, and Function
  %abc = OpVariable %_ptr_UniformConstant_bool UniformConstant

GLSL shader:

#version 430

layout(location=0) uniform bool abc;

void main() {
}

Compiled with:

glslangValidator -G test.vert

Disassembly of compiled SPIR-V code:

; SPIR-V
; Version: 1.0
; Generator: Khronos Glslang Reference Front End; 8
; Bound: 13
; Schema: 0
               OpCapability Shader
          %1 = OpExtInstImport "GLSL.std.450"
               OpMemoryModel Logical GLSL450
               OpEntryPoint Vertex %main "main" %gl_VertexID %gl_InstanceID
               OpSource GLSL 430
               OpName %main "main"
               OpName %abc "abc"
               OpName %gl_VertexID "gl_VertexID"
               OpName %gl_InstanceID "gl_InstanceID"
               OpDecorate %abc Location 0
               OpDecorate %gl_VertexID BuiltIn VertexId
               OpDecorate %gl_InstanceID BuiltIn InstanceId
       %void = OpTypeVoid
          %3 = OpTypeFunction %void
       %bool = OpTypeBool
%_ptr_UniformConstant_bool = OpTypePointer UniformConstant %bool
        %abc = OpVariable %_ptr_UniformConstant_bool UniformConstant
        %int = OpTypeInt 32 1
%_ptr_Input_int = OpTypePointer Input %int
%gl_VertexID = OpVariable %_ptr_Input_int Input
%gl_InstanceID = OpVariable %_ptr_Input_int Input
       %main = OpFunction %void None %3
          %5 = OpLabel
               OpReturn
               OpFunctionEnd

Possibly regression in #1872 (CC @jaebaek, linked issue #1405). Tested with latest master versions of glslang and SPIRV-Tools.

[johnkslang]

Are you targeting OpenGL?

This functionality does not exist in Vulkan, and hence might be a hole in some tools or specifications.

[rdb]

Yes, I'm targeting OpenGL. Explicitly specifying OpenGL target to spirv-val does not solve the problem.

[johnkslang]

I suspect the specifications should be updated to allow Boolean type for this purpose.

[rdb]

Where should I file bugs against the SPIR-V specification?

[johnkslang]

File SPIR-V specification bugs at https://github.com/KhronosGroup/SPIRV-Registry.

Thanks.

[s-perron]

The tooling will be updated once the spec is changed. Closing this issue.

[rdb]

Tooling was already updated actually in anticipation of a future spec change, see #5237