validate vertex stage returns the position built-in

src/valid/interface.rs

@@ -63,6 +63,8 @@ pub enum VaryingError {
 pub enum EntryPointError {
     #[error("Multiple conflicting entry points")]
     Conflict,
+    #[error("Missing position built-in output value")]
+    MissingVertexOutputPosition,
     #[error("Early depth test is not applicable")]
     UnexpectedEarlyDepthTest,
     #[error("Workgroup size is not applicable")]
@@ -353,7 +355,6 @@ impl VaryingContext<'_> {
                 .map_err(|e| e.with_span_context(span_context)),
             None => {
                 match self.types[ty].inner {
-                    //TODO: check the member types
                     crate::TypeInner::Struct { ref members, .. } => {
                         for (index, member) in members.iter().enumerate() {
                             let span_context = self.types.get_span_context(ty);
@@ -369,7 +370,6 @@ impl VaryingContext<'_> {
                                     #[cfg(not(feature = "validate"))]
                                     let _ = index;
                                 }
-                                // TODO: shouldn't this be validate?
                                 Some(ref binding) => self
                                     .validate_impl(member.ty, binding)
                                     .map_err(|e| e.with_span_context(span_context))?,
@@ -545,6 +545,33 @@ impl super::Validator {
             return Err(EntryPointError::UnexpectedWorkgroupSize.with_span());
         }
 
+        #[cfg(feature = "validate")]
+        if ep.stage == crate::ShaderStage::Vertex {
+            let has_position = match ep.function.result {
+                Some(ref res) => {
+                    const fn is_pos(binding: &crate::Binding) -> bool {
+                        matches!(
+                            binding,
+                            &crate::Binding::BuiltIn(crate::BuiltIn::Position { .. })
+                        )
+                    }
+                    match res.binding {
+                        Some(ref binding) => is_pos(binding),
+                        None => match module.types[res.ty].inner {
+                            crate::TypeInner::Struct { ref members, .. } => members
+                                .iter()
+                                .any(|member| member.binding.as_ref().map(is_pos).unwrap_or(false)),
+                            _ => false,
+                        },
+                    }
+                }
+                None => false,
+            };
+            if !has_position {
+                return Err(EntryPointError::MissingVertexOutputPosition.with_span());
+            }
+        }
+
         let info = self
             .validate_function(&ep.function, module, mod_info, true)
             .map_err(WithSpan::into_other)?;

tests/in/functions-webgl.wgsl

@@ -7,7 +7,7 @@ fn test_fma() -> vec2<f32> {
 }
 
 
-@vertex
+@fragment
 fn main() {
     let a = test_fma();
 }

tests/in/math-functions.wgsl

@@ -1,4 +1,4 @@
-@vertex
+@fragment
 fn main() {
     let f = 1.0;
     let v = vec4<f32>(0.0);

tests/in/multiview.wgsl

@@ -1,2 +1,2 @@
-@vertex 
+@fragment
 fn main(@builtin(view_index) view_index: i32) {}

tests/in/multiview_webgl.wgsl

@@ -1,2 +1,2 @@
-@vertex 
+@fragment
 fn main(@builtin(view_index) view_index: i32) {}

tests/in/spv/degrees.spvasm

@@ -0,0 +1,47 @@
+; SPIR-V
+; Version: 1.0
+; Generator: Khronos Glslang Reference Front End; 10
+; Bound: 27
+; Schema: 0
+               OpCapability Shader
+          %1 = OpExtInstImport "GLSL.std.450"
+               OpMemoryModel Logical GLSL450
+               OpEntryPoint Fragment %main "main" %colour
+               OpSource GLSL 450
+               OpName %main "main"
+               OpName %deg "deg"
+               OpName %rad "rad"
+               OpName %deg_again "deg_again"
+               OpName %colour "colour"
+               OpDecorate %colour Location 0
+       %void = OpTypeVoid
+          %3 = OpTypeFunction %void
+      %float = OpTypeFloat 32
+%_ptr_Function_float = OpTypePointer Function %float
+   %float_15 = OpConstant %float 15
+    %v4float = OpTypeVector %float 4
+%_ptr_Output_v4float = OpTypePointer Output %v4float
+     %colour = OpVariable %_ptr_Output_v4float Output
+    %v3float = OpTypeVector %float 3
+    %float_1 = OpConstant %float 1
+       %main = OpFunction %void None %3
+          %5 = OpLabel
+        %deg = OpVariable %_ptr_Function_float Function
+        %rad = OpVariable %_ptr_Function_float Function
+  %deg_again = OpVariable %_ptr_Function_float Function
+               OpStore %deg %float_15
+         %11 = OpLoad %float %deg
+         %12 = OpExtInst %float %1 Radians %11
+               OpStore %rad %12
+         %14 = OpLoad %float %rad
+         %15 = OpExtInst %float %1 Degrees %14
+               OpStore %deg_again %15
+         %19 = OpLoad %float %deg_again
+         %21 = OpCompositeConstruct %v3float %19 %19 %19
+         %23 = OpCompositeExtract %float %21 0
+         %24 = OpCompositeExtract %float %21 1
+         %25 = OpCompositeExtract %float %21 2
+         %26 = OpCompositeConstruct %v4float %23 %24 %25 %float_1
+               OpStore %colour %26
+               OpReturn
+               OpFunctionEnd

tests/in/spv/inv-hyperbolic-trig-functions.spvasm

@@ -0,0 +1,37 @@
+; SPIR-V
+; Version: 1.0
+; Generator: Khronos Glslang Reference Front End; 10
+; Bound: 19
+; Schema: 0
+               OpCapability Shader
+          %1 = OpExtInstImport "GLSL.std.450"
+               OpMemoryModel Logical GLSL450
+               OpEntryPoint Fragment %main "main"
+               OpSource GLSL 450
+               OpName %main "main"
+               OpName %b "b"
+               OpName %a "a"
+               OpName %c "c"
+               OpName %d "d"
+       %void = OpTypeVoid
+          %3 = OpTypeFunction %void
+      %float = OpTypeFloat 32
+%_ptr_Function_float = OpTypePointer Function %float
+%_ptr_Private_float = OpTypePointer Private %float
+          %a = OpVariable %_ptr_Private_float Private
+       %main = OpFunction %void None %3
+          %5 = OpLabel
+          %b = OpVariable %_ptr_Function_float Function
+          %c = OpVariable %_ptr_Function_float Function
+          %d = OpVariable %_ptr_Function_float Function
+         %11 = OpLoad %float %a
+         %12 = OpExtInst %float %1 Asinh %11
+               OpStore %b %12
+         %14 = OpLoad %float %a
+         %15 = OpExtInst %float %1 Acosh %14
+               OpStore %c %15
+         %17 = OpLoad %float %a
+         %18 = OpExtInst %float %1 Atanh %17
+               OpStore %d %18
+               OpReturn
+               OpFunctionEnd

tests/in/spv/quad-vert.spvasm

@@ -0,0 +1,61 @@
+; SPIR-V
+; Version: 1.0
+; Generator: Khronos Glslang Reference Front End; 10
+; Bound: 31
+; Schema: 0
+               OpCapability Shader
+          %1 = OpExtInstImport "GLSL.std.450"
+               OpMemoryModel Logical GLSL450
+               OpEntryPoint Vertex %main "main" %v_uv %a_uv %_ %a_pos
+               OpSource GLSL 460
+               OpName %main "main"
+               OpName %v_uv "v_uv"
+               OpName %a_uv "a_uv"
+               OpName %gl_PerVertex "gl_PerVertex"
+               OpMemberName %gl_PerVertex 0 "gl_Position"
+               OpMemberName %gl_PerVertex 1 "gl_PointSize"
+               OpMemberName %gl_PerVertex 2 "gl_ClipDistance"
+               OpMemberName %gl_PerVertex 3 "gl_CullDistance"
+               OpName %_ ""
+               OpName %a_pos "a_pos"
+               OpDecorate %v_uv Location 0
+               OpDecorate %a_uv Location 1
+               OpMemberDecorate %gl_PerVertex 0 BuiltIn Position
+               OpMemberDecorate %gl_PerVertex 1 BuiltIn PointSize
+               OpMemberDecorate %gl_PerVertex 2 BuiltIn ClipDistance
+               OpMemberDecorate %gl_PerVertex 3 BuiltIn CullDistance
+               OpDecorate %gl_PerVertex Block
+               OpDecorate %a_pos Location 0
+       %void = OpTypeVoid
+          %3 = OpTypeFunction %void
+      %float = OpTypeFloat 32
+    %v2float = OpTypeVector %float 2
+%_ptr_Output_v2float = OpTypePointer Output %v2float
+       %v_uv = OpVariable %_ptr_Output_v2float Output
+%_ptr_Input_v2float = OpTypePointer Input %v2float
+       %a_uv = OpVariable %_ptr_Input_v2float Input
+    %v4float = OpTypeVector %float 4
+       %uint = OpTypeInt 32 0
+     %uint_1 = OpConstant %uint 1
+%_arr_float_uint_1 = OpTypeArray %float %uint_1
+%gl_PerVertex = OpTypeStruct %v4float %float %_arr_float_uint_1 %_arr_float_uint_1
+%_ptr_Output_gl_PerVertex = OpTypePointer Output %gl_PerVertex
+          %_ = OpVariable %_ptr_Output_gl_PerVertex Output
+        %int = OpTypeInt 32 1
+      %int_0 = OpConstant %int 0
+      %a_pos = OpVariable %_ptr_Input_v2float Input
+    %float_0 = OpConstant %float 0
+    %float_1 = OpConstant %float 1
+%_ptr_Output_v4float = OpTypePointer Output %v4float
+       %main = OpFunction %void None %3
+          %5 = OpLabel
+         %12 = OpLoad %v2float %a_uv
+               OpStore %v_uv %12
+         %23 = OpLoad %v2float %a_pos
+         %26 = OpCompositeExtract %float %23 0
+         %27 = OpCompositeExtract %float %23 1
+         %28 = OpCompositeConstruct %v4float %26 %27 %float_0 %float_1
+         %30 = OpAccessChain %_ptr_Output_v4float %_ %int_0
+               OpStore %30 %28
+               OpReturn
+               OpFunctionEnd