The CMake files now build two targets: volk and volk_headers. The first is a static library where platform defines can be set using VOLK_STATIC_DEFINES, the latter is for the header-only approach.

- Refactored the tests to test all relevant situations, and added testing for whether setting the platform defines actually worked.
- Added a bash script to run the test cases locally. The travis script now just calls that script.
- Changed the Vulkan header version detection in CMakeLists.txt to be more in line with the volk approach: it is now written at generate time just like the volk sources.
- Fixed a bug from trunk that could break the Win32 build (missing defined() in volk.h:27)

Author: Jens Weggemann

.travis.yml

@@ -12,26 +12,4 @@ script:
   - git clone --depth 1 https://github.com/KhronosGroup/Vulkan-Headers
   - export VULKAN_SDK=$PWD/Vulkan-Headers
   - popd
-  #
-  # Install volk into local directory.
-  #
-  - mkdir installed
-  - mkdir build
-  - pushd build
-  - cmake -DVOLK_INSTALL=ON -DCMAKE_INSTALL_PREFIX=../installed ..
-  - cmake --build . --config Debug
-  - cmake --build . --config Release
-  - cmake --build . --target install
-  - popd
-  - export INSTALL_DIR=$PWD/installed
-  #
-  # Build examples
-  #
-  - pushd test
-  - mkdir build
-  - pushd build
-  - cmake -DCMAKE_PREFIX_PATH=${INSTALL_DIR}/lib/cmake ..
-  - cmake --build . --config Debug
-  - cmake --build . --config Release
-  - popd
-  - popd
+  - test/run_tests.sh

CMakeLists.txt

@@ -2,37 +2,72 @@ cmake_minimum_required(VERSION 3.0)
 cmake_policy(PUSH)
 cmake_policy(SET CMP0048 NEW) # project(... VERSION ...) support
 
-# Set the project version to the vulkan header version.
-file(STRINGS volk.h matched_line REGEX "#define[ \t]+VOLK_HEADER_VERSION" LIMIT_INPUT 1000)
-string(REGEX MATCH "([0-9\\.]+)$" parsed_version ${matched_line})
-if(NOT parsed_version)
-  message(FATAL_ERROR "Failed to parse VOLK_HEADER_VERSION!")
+project(volk VERSION 
+# VOLK_GENERATE_VERSION
+121
+# VOLK_GENERATE_VERSION
+  LANGUAGES C
+)
+
+# CMake 3.12 changes the default behaviour of option() to leave local variables
+# unchanged if they exist (which we want), but we must work with older CMake versions.
+if(NOT DEFINED VOLK_STATIC_DEFINES)
+  option(VOLK_STATIC_DEFINES "Additional defines for building the volk static library, e.g. Vulkan platform defines" "")
+endif()
+if(NOT DEFINED VOLK_PULL_IN_VULKAN)
+  option(VOLK_PULL_IN_VULKAN "Vulkan as a transitive dependency" ON)
+endif()
+if(NOT DEFINED VOLK_INSTALL)
+  option(VOLK_INSTALL "Create installation targets" OFF)
 endif()
 
-project(volk VERSION ${parsed_version} LANGUAGES NONE)
+# -----------------------------------------------------
+# Static library
 
-add_library(volk INTERFACE)
-target_include_directories(volk INTERFACE
-    $<BUILD_INTERFACE:${CMAKE_CURRENT_LIST_DIR}>
-    $<INSTALL_INTERFACE:include>
+add_library(volk STATIC volk.h volk.c)
+target_include_directories(volk PUBLIC
+  $<BUILD_INTERFACE:${CMAKE_CURRENT_LIST_DIR}>
+  $<INSTALL_INTERFACE:include>
 )
+if(VOLK_STATIC_DEFINES)
+  target_compile_definitions(volk PUBLIC ${VOLK_STATIC_DEFINES})
+endif()
 if (NOT WIN32)
-    target_link_libraries(volk INTERFACE dl)
+  target_link_libraries(volk PUBLIC dl)
 endif()
 
-# If CMake has the FindVulkan module and it works, use it.
-# Otherwise silently rely on the environment variable.
-find_package(Vulkan QUIET)
+# -----------------------------------------------------
+# Interface library
 
-if(NOT VOLK_INSTALL)
+add_library(volk_headers INTERFACE)
+target_include_directories(volk_headers INTERFACE
+  $<BUILD_INTERFACE:${CMAKE_CURRENT_LIST_DIR}>
+  $<INSTALL_INTERFACE:include>
+)
+if (NOT WIN32)
+  target_link_libraries(volk_headers INTERFACE dl)
+endif()
+
+# -----------------------------------------------------
+# Vulkan transitive dependency
+
+if(VOLK_PULL_IN_VULKAN)
+  # If CMake has the FindVulkan module and it works, use it.
+  # Otherwise try the environment variable.
+  find_package(Vulkan QUIET)
   if(TARGET Vulkan::Vulkan)
-    target_link_libraries(volk INTERFACE Vulkan::Vulkan)
+      message(" Vulkan as target")
+    target_link_libraries(volk PUBLIC Vulkan::Vulkan)
+    target_link_libraries(volk_headers INTERFACE Vulkan::Vulkan)
   elseif(DEFINED ENV{VULKAN_SDK})
-    target_include_directories(volk INTERFACE "$ENV{VULKAN_SDK}/include")
+      message(" Vulkan as path")
+    target_include_directories(volk PUBLIC "$ENV{VULKAN_SDK}/include")
+    target_include_directories(volk_headers INTERFACE "$ENV{VULKAN_SDK}/include")
   endif()
 endif()
 
-option(VOLK_INSTALL "Create installation target" OFF)
+# -----------------------------------------------------
+# Installation
 
 if(VOLK_INSTALL)
 
@@ -43,7 +78,12 @@ if(VOLK_INSTALL)
   install(FILES volk.h volk.c DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
 
   # Install library target and add it and any dependencies to export set.
-  install(TARGETS volk EXPORT volk-targets)
+  install(TARGETS volk volk_headers
+    EXPORT volk-targets
+    LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
+    ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
+    RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
+  )
 
   # Actually write exported config w/ imported targets
   install(EXPORT volk-targets

cmake/volkConfig.cmake.in

@@ -3,11 +3,19 @@ get_filename_component(volk_CMAKE_DIR "${CMAKE_CURRENT_LIST_FILE}" PATH)
 if(NOT TARGET volk::volk)
   include("${volk_CMAKE_DIR}/volkTargets.cmake")
 endif()
-set(volk_LIBRARIES volk::volk)
 
-find_package(Vulkan QUIET)
-if(TARGET Vulkan::Vulkan) 
-  add_dependencies(volk::volk Vulkan::Vulkan)
-elseif(DEFINED ENV{VULKAN_SDK})
-  target_include_directories(volk::volk INTERFACE "$ENV{VULKAN_SDK}/include")
+# Mirror the default behaviour of the respective option.
+if(NOT DEFINED VOLK_PULL_IN_VULKAN)
+    set(VOLK_PULL_IN_VULKAN ON)
+endif()
+
+if(VOLK_PULL_IN_VULKAN)
+  find_package(Vulkan QUIET)
+  if(TARGET Vulkan::Vulkan) 
+    add_dependencies(volk::volk Vulkan::Vulkan)
+    add_dependencies(volk::volk_headers Vulkan::Vulkan)
+  elseif(DEFINED ENV{VULKAN_SDK})
+    target_include_directories(volk::volk INTERFACE "$ENV{VULKAN_SDK}/include")
+    target_include_directories(volk::volk_headers INTERFACE "$ENV{VULKAN_SDK}/include")
+  endif()
 endif()

generate.py

@@ -25,9 +25,14 @@ def patch_file(path, blocks):
 					block = None
 			else:
 				result.append(line)
+                                # C comment marker
 				if line.strip().startswith('/* VOLK_GENERATE_'):
 					block = line
 					result.append(blocks[line.strip()[17:-3]])
+                                # Shell/CMake comment marker
+				elif line.strip().startswith('# VOLK_GENERATE_'):
+					block = line
+					result.append(blocks[line.strip()[16:]])
 
 	with open(path, 'w') as file:
 		for line in result:
@@ -60,7 +65,8 @@ def defined(key):
 	blocks = {}
 
 	version = spec.find('types/type[name="VK_HEADER_VERSION"]')
-	blocks['VERSION'] = '#define VOLK_HEADER_VERSION ' + version.find('name').tail.strip() + '\n'
+	blocks['VERSION'] = version.find('name').tail.strip() + '\n'
+	blocks['VERSION_DEFINE'] = '#define VOLK_HEADER_VERSION ' + version.find('name').tail.strip() + '\n'
 
 	command_groups = OrderedDict()
 	instance_commands = set()
@@ -160,3 +166,4 @@ def defined(key):
 
 	patch_file('volk.h', blocks)
 	patch_file('volk.c', blocks)
+	patch_file('CMakeLists.txt', blocks)

test/CMakeLists.txt

@@ -0,0 +1,9 @@
+cmake_minimum_required(VERSION 3.0)
+project(volk_test LANGUAGES C)
+
+# Include volk from a CMake package config.
+# CMAKE_PREFIX_PATH or volk_DIR must be set properly.
+find_package(volk CONFIG REQUIRED)
+
+add_executable(volk_test main.c)
+target_link_libraries(volk_test PRIVATE volk::volk_headers)

test/cmake_usage_source/CMakeLists.txt

@@ -0,0 +1,54 @@
+/* Set platform defines at build time for volk to pick up. */
+#if defined(_WIN32)
+#   define VK_USE_PLATFORM_WIN32_KHR
+#elif defined(__linux__) || defined(__unix__)
+#   define VK_USE_PLATFORM_XLIB_KHR
+#elif defined(__APPLE__)
+#   define VK_USE_PLATFORM_MACOS_MVK
+#else
+#   error "Platform not supported by this example."
+#endif
+
+#define VOLK_IMPLEMENTATION
+#include "volk.h"
+
+#include "stdio.h"
+#include "stdlib.h"
+
+int main()
+{
+    VkResult r;
+    uint32_t version;
+    void* ptr;
+
+    /* This won't compile if the appropriate Vulkan platform define isn't set. */
+    ptr = 
+#if defined(_WIN32)
+    &vkCreateWin32SurfaceKHR;
+#elif defined(__linux__) || defined(__unix__)
+    &vkCreateXlibSurfaceKHR;
+#elif defined(__APPLE__)
+    &vkCreateMacOSSurfaceMVK;
+#else
+    /* Platform not recogized for testing. */
+    NULL;
+#endif
+
+    /* Try to initialize volk. This might not work on CI builds, but the
+     * above should have compiled at least. */
+    r = volkInitialize();
+    if (r != VK_SUCCESS) {
+        printf("volkInitialize failed!\n");
+        return -1;
+    }
+
+    version = volkGetInstanceVersion();
+    printf("Vulkan version %d.%d.%d initialized.\n",
+            VK_VERSION_MAJOR(version),
+            VK_VERSION_MINOR(version),
+            VK_VERSION_PATCH(version));
+
+
+    return 0;
+}
+