layersvt: Add common layer foundation library and unit tests

layersvt/CMakeLists.txt

@@ -45,6 +45,8 @@ else()
     add_compile_options(-Wpointer-arith)
 endif()
 
+add_subdirectory(common)
+
 if(BUILD_APIDUMP)
     find_package(Python3 REQUIRED)
 
@@ -116,7 +118,7 @@ if(BUILD_SCREENSHOT)
         vk_layer_table.cpp
         vk_layer_table.h
         screenshot/screenshot_layer.md
-        layer_keep_alive.cpp
+        common/layer_keep_alive.cpp
         screenshot/json/VkLayer_screenshot.json.in
     )
 endif()
@@ -136,7 +138,7 @@ if(BUILD_CPUTIMING)
         ../scripts/generators/cputiming_generator.py
         vk_layer_table.cpp
         vk_layer_table.h
-        layer_keep_alive.cpp
+        common/layer_keep_alive.cpp
         cpu_timing/VkLayer_CPUTiming.json.in
     )
 
@@ -178,7 +180,7 @@ if(BUILD_DEBUGMARKER)
         perfetto/perfetto.cc
         vk_layer_table.cpp
         vk_layer_table.h
-        layer_keep_alive.cpp
+        common/layer_keep_alive.cpp
         debug_marker/VkLayer_DebugMarker.json.in
     )
 
@@ -214,7 +216,7 @@ if(BUILD_DEVICEMEMORYREPORT)
         perfetto/perfetto.cc
         vk_layer_table.cpp
         vk_layer_table.h
-        layer_keep_alive.cpp
+        common/layer_keep_alive.cpp
         device_memory_report/VkLayer_DeviceMemoryReport.json.in
     )
 

layersvt/README.md

@@ -22,6 +22,7 @@ Layers are activated at vkCreateInstance time.  Layers can also be activated via
 Note that some layers are code-generated and will therefore exist in the directory (build_dir)/layers
 
 -include/vkLayer.h  - header file for layer code.
+- [common/README.md](common/README.md) - Common layer foundation library (`layersvt_common`) and guide for creating new layers.
 
 ### Print API Calls and Parameter Values
 (build dir)/layers/api_dump.cpp (name=VK_LAYER_LUNARG_api_dump) - print out API calls along with parameter values

layersvt/common/CMakeLists.txt

@@ -0,0 +1,55 @@
+# Copyright (C) 2026 Google Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+add_library(layersvt_common OBJECT
+    dispatch_table_manager.h
+    dispatch_table_manager.cpp
+    layer_manifest.h
+    layer_manifest.cpp
+    layer_base.h
+    layer_base.cpp
+    dispatch_downstream.h
+)
+
+set_target_properties(layersvt_common PROPERTIES
+    FOLDER "layers/common"
+    POSITION_INDEPENDENT_CODE ON
+)
+
+target_include_directories(layersvt_common PUBLIC
+    ${CMAKE_CURRENT_SOURCE_DIR}/..
+)
+
+target_link_libraries(layersvt_common PUBLIC
+    Vulkan::Headers
+    Vulkan::UtilityHeaders
+)
+if (ANDROID)
+    target_sources(layersvt_common PRIVATE
+        layer_keep_alive.cpp
+    )
+    target_link_libraries(layersvt_common PUBLIC ${CMAKE_DL_LIBS})
+endif()
+
+add_library(layersvt_entrypoints OBJECT
+    layer_entrypoints.cpp
+)
+
+set_target_properties(layersvt_entrypoints PROPERTIES
+    FOLDER "layers/common"
+)
+
+target_link_libraries(layersvt_entrypoints PRIVATE
+    layersvt_common
+)