layers: Improve Mesh GPL error message

Author: spencer-lunarg

layers/core_checks/cc_pipeline_graphics.cpp

@@ -499,12 +499,17 @@ bool CoreChecks::ValidateGraphicsPipelineVertexInputState(const vvl::Pipeline &p
         // Failed to defined a Vertex Input State
         if (!pipeline.pre_raster_state) {
             skip |= LogError("VUID-VkGraphicsPipelineCreateInfo-flags-08898", device, create_info_loc,
-                             "pVertexInputState and pInputAssemblyState are both NULL so this is an invalid Vertex Input State (no "
-                             "dynamic state or mesh shaders were used to ignore them).");
+                             "pVertexInputState and pInputAssemblyState are both NULL so this is an invalid Vertex Input "
+                             "State.\npVertexInputState can be ignored with VK_DYNAMIC_STATE_VERTEX_INPUT_EXT\npInputAssemblyState "
+                             "can be ignored with VK_DYNAMIC_STATE_PRIMITIVE_RESTART_ENABLE, VK_DYNAMIC_STATE_PRIMITIVE_TOPOLOGY, "
+                             "and dynamicPrimitiveTopologyUnrestricted set to VK_TRUE\nIf there is a mesh stage, these are also "
+                             "ignored, but the Vertex Input library can just be skipped if creating a mesh pipeline.");
         } else if ((pipeline.active_shaders & VK_SHADER_STAGE_VERTEX_BIT)) {
             skip |= LogError("VUID-VkGraphicsPipelineCreateInfo-flags-08897", device, create_info_loc,
-                             "pVertexInputState and pInputAssemblyState are both NULL so this is an invalid Vertex Input State (no "
-                             "dynamic state were used to ignore them).");
+                             "pVertexInputState and pInputAssemblyState are both NULL so this is an invalid Vertex Input "
+                             "State.\npVertexInputState can be ignored with VK_DYNAMIC_STATE_VERTEX_INPUT_EXT\npInputAssemblyState "
+                             "can be ignored with VK_DYNAMIC_STATE_PRIMITIVE_RESTART_ENABLE,  VK_DYNAMIC_STATE_PRIMITIVE_TOPOLOGY, "
+                             "and dynamicPrimitiveTopologyUnrestricted set to VK_TRUE");
         }
     } else if (invalid_input_state) {
         skip |= LogError("VUID-VkGraphicsPipelineCreateInfo-pStages-02097", device, create_info_loc.dot(Field::pVertexInputState),

tests/unit/graphics_library_positive.cpp

@@ -11,6 +11,7 @@
  *     http://www.apache.org/licenses/LICENSE-2.0
  */
 
+#include <spirv-tools/libspirv.h>
 #include "../framework/layer_validation_tests.h"
 #include "../framework/pipeline_helper.h"
 #include "../framework/descriptor_helper.h"
@@ -2198,4 +2199,53 @@ TEST_F(PositiveGraphicsLibrary, DestroyImmutableSampler) {
     VkGraphicsPipelineCreateInfo lib_ci = vku::InitStructHelper(&link_info);
     lib_ci.layout = pipeline_layout2;
     vkt::Pipeline exe_pipe(*m_device, lib_ci);
-}
+}
+
+TEST_F(PositiveGraphicsLibrary, Mesh) {
+    TEST_DESCRIPTION("https://gitlab.khronos.org/vulkan/vulkan/-/issues/4433");
+    SetTargetApiVersion(VK_API_VERSION_1_3);
+    AddRequiredExtensions(VK_EXT_MESH_SHADER_EXTENSION_NAME);
+    AddRequiredFeature(vkt::Feature::meshShader);
+    AddRequiredFeature(vkt::Feature::maintenance4);
+    RETURN_IF_SKIP(InitBasicGraphicsLibrary());
+    InitRenderTarget();
+
+    VkPipelineLayout layout = VK_NULL_HANDLE;
+
+    CreatePipelineHelper pre_raster_lib(*this);
+    {
+        const auto ms_spv = GLSLToSPV(VK_SHADER_STAGE_MESH_BIT_EXT, kMeshMinimalGlsl, SPV_ENV_VULKAN_1_3);
+        vkt::GraphicsPipelineLibraryStage ms_stage(ms_spv, VK_SHADER_STAGE_MESH_BIT_EXT);
+        pre_raster_lib.InitPreRasterLibInfo(&ms_stage.stage_ci);
+        pre_raster_lib.CreateGraphicsPipeline();
+    }
+
+    layout = pre_raster_lib.gp_ci_.layout;
+
+    CreatePipelineHelper frag_shader_lib(*this);
+    {
+        const auto fs_spv = GLSLToSPV(VK_SHADER_STAGE_FRAGMENT_BIT, kFragmentMinimalGlsl);
+        vkt::GraphicsPipelineLibraryStage fs_stage(fs_spv, VK_SHADER_STAGE_FRAGMENT_BIT);
+        frag_shader_lib.InitFragmentLibInfo(&fs_stage.stage_ci);
+        frag_shader_lib.gp_ci_.layout = layout;
+        frag_shader_lib.CreateGraphicsPipeline(false);
+    }
+
+    CreatePipelineHelper frag_out_lib(*this);
+    frag_out_lib.InitFragmentOutputLibInfo();
+    frag_out_lib.CreateGraphicsPipeline(false);
+
+    // Vertex input lib not required for mesh
+    VkPipeline libraries[3] = {
+        pre_raster_lib,
+        frag_shader_lib,
+        frag_out_lib,
+    };
+    VkPipelineLibraryCreateInfoKHR link_info = vku::InitStructHelper();
+    link_info.libraryCount = size32(libraries);
+    link_info.pLibraries = libraries;
+
+    VkGraphicsPipelineCreateInfo exe_pipe_ci = vku::InitStructHelper(&link_info);
+    exe_pipe_ci.layout = pre_raster_lib.gp_ci_.layout;
+    vkt::Pipeline exe_pipe(*m_device, exe_pipe_ci);
+}