glsl: handle mesh shader primitive type layout qualifier

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Acked-by: Marek Olšák <marek.olsak@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/36405>

src/compiler/glsl/ast_type.cpp

@@ -588,6 +588,23 @@ ast_type_qualifier::validate_out_qualifier(YYLTYPE *loc,
    case MESA_SHADER_FRAGMENT:
       valid_out_mask.flags.q.blend_support = 1;
       break;
+   case MESA_SHADER_MESH:
+      if (this->flags.q.prim_type) {
+         /* Make sure this is a valid output primitive type. */
+         switch (this->prim_type) {
+         case GL_POINTS:
+         case GL_LINES:
+         case GL_TRIANGLES:
+            break;
+         default:
+            r = false;
+            _mesa_glsl_error(loc, state, "invalid mesh shader output "
+                             "primitive type");
+            break;
+         }
+      }
+      valid_out_mask.flags.q.prim_type = 1;
+      break;
    default:
       r = false;
       _mesa_glsl_error(loc, state,

src/compiler/glsl/gl_nir_linker.c

@@ -2558,6 +2558,40 @@ link_cs_input_layout_qualifiers(struct gl_shader_program *prog,
 }
 
 
+static void
+link_ms_inout_layout_qualifiers(struct gl_shader_program *prog,
+                                struct gl_program *gl_prog,
+                                struct gl_shader **shader_list,
+                                unsigned num_shaders)
+{
+   if (gl_prog->info.stage != MESA_SHADER_MESH)
+      return;
+
+   enum mesa_prim prim_type = MESA_PRIM_UNKNOWN;
+
+   for (unsigned i = 0; i < num_shaders; i++) {
+      struct gl_shader *shader = shader_list[i];
+
+      if (shader->info.Mesh.OutputType != MESA_PRIM_UNKNOWN) {
+         if (prim_type != MESA_PRIM_UNKNOWN &&
+             prim_type != shader->info.Mesh.OutputType) {
+            linker_error(prog, "mesh shader defined with conflicting "
+                         "output types\n");
+            return;
+         }
+         prim_type = shader->info.Mesh.OutputType;
+      }
+   }
+
+   if (prim_type == MESA_PRIM_UNKNOWN) {
+      linker_error(prog, "mesh shader didn't declare primitive output type\n");
+      return;
+   } else {
+      gl_prog->nir->info.mesh.primitive_type = prim_type;
+   }
+}
+
+
 /**
  * Combine a group of shaders for a single stage to generate a linked shader
  *
@@ -2689,6 +2723,7 @@ link_intrastage_shaders(void *mem_ctx,
    link_tes_in_layout_qualifiers(prog, gl_prog, shader_list, num_shaders);
    link_gs_inout_layout_qualifiers(prog, gl_prog, shader_list, num_shaders);
    link_cs_input_layout_qualifiers(prog, gl_prog, shader_list, num_shaders);
+   link_ms_inout_layout_qualifiers(prog, gl_prog, shader_list, num_shaders);
 
    if (linked->Stage != MESA_SHADER_FRAGMENT)
       link_xfb_stride_layout_qualifiers(&ctx->Const, prog, shader_list, num_shaders);

src/compiler/glsl/glsl_parser.yy

@@ -1328,7 +1328,7 @@ layout_qualifier_id:
          }
 
          if ($$.flags.i && !state->has_geometry_shader() &&
-             !state->has_tessellation_shader()) {
+             !state->has_tessellation_shader() && !state->EXT_mesh_shader_enable) {
             _mesa_glsl_error(& @1, state, "#version 150 layout "
                              "qualifier `%s' used", $1);
          }

src/compiler/glsl/glsl_parser_extras.cpp

@@ -2099,6 +2099,15 @@ set_shader_inout_layout(struct gl_shader *shader,
       shader->BlendSupport = state->fs_blend_support;
       break;
 
+   case MESA_SHADER_MESH:
+      if (state->out_qualifier->flags.q.prim_type) {
+         shader->info.Mesh.OutputType =
+            gl_to_mesa_prim(state->out_qualifier->prim_type);
+      } else {
+         shader->info.Mesh.OutputType = MESA_PRIM_UNKNOWN;
+      }
+      break;
+
    default:
       /* Nothing to do. */
       break;

src/mesa/main/shader_types.h

@@ -132,6 +132,13 @@ struct gl_shader_info
        */
       enum gl_derivative_group DerivativeGroup;
    } Comp;
+
+   /**
+    * Mesh shader state from EXT_mesh_shader
+    */
+   struct {
+      enum mesa_prim OutputType;
+   } Mesh;
 };
 
 /**