cmake: Now generates Wayland protocol source bits like the configure script.

Fixes Bugzilla #3430.

cmake/sdlchecks.cmake

@@ -539,6 +539,27 @@ macro(CheckMir)
     endif()
 endmacro()
 
+macro(WaylandProtocolGen _SCANNER _XML _PROTL)
+    set(_WAYLAND_PROT_C_CODE "${CMAKE_CURRENT_BINARY_DIR}/wayland-generated-protocols/${_PROTL}-protocol.c")
+    set(_WAYLAND_PROT_H_CODE "${CMAKE_CURRENT_BINARY_DIR}/wayland-generated-protocols/${_PROTL}-client-protocol.h")
+
+    add_custom_command(
+        OUTPUT "${_WAYLAND_PROT_H_CODE}"
+        DEPENDS "${_XML}"
+        COMMAND "${_SCANNER}"
+        ARGS client-header "${_XML}" "${_WAYLAND_PROT_H_CODE}"
+    )
+
+    add_custom_command(
+        OUTPUT "${_WAYLAND_PROT_C_CODE}"
+        DEPENDS "${_WAYLAND_PROT_H_CODE}"
+        COMMAND "${_SCANNER}"
+        ARGS code "${_XML}" "${_WAYLAND_PROT_C_CODE}"
+    )
+
+    set(SOURCE_FILES ${SOURCE_FILES} "${CMAKE_CURRENT_BINARY_DIR}/wayland-generated-protocols/${_PROTL}-protocol.c")
+endmacro()
+
 # Requires:
 # - EGL
 # - PkgCheckModules
@@ -547,7 +568,51 @@ endmacro()
 # - HAVE_DLOPEN opt
 macro(CheckWayland)
   if(VIDEO_WAYLAND)
-    pkg_check_modules(WAYLAND wayland-client wayland-cursor wayland-egl egl xkbcommon)
+    pkg_check_modules(WAYLAND wayland-client wayland-scanner wayland-protocols wayland-egl wayland-cursor egl xkbcommon)
+
+    # We have to generate some protocol interface code for some various Wayland features.
+    if(WAYLAND_FOUND)
+      execute_process(
+        COMMAND ${PKG_CONFIG_EXECUTABLE} --variable=pkgdatadir wayland-client
+        WORKING_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}"
+        RESULT_VARIABLE WAYLAND_CORE_PROTOCOL_DIR_RC
+        OUTPUT_VARIABLE WAYLAND_CORE_PROTOCOL_DIR
+        ERROR_QUIET
+        OUTPUT_STRIP_TRAILING_WHITESPACE
+      )
+      if(NOT WAYLAND_CORE_PROTOCOL_DIR_RC EQUAL 0)
+        set(WAYLAND_FOUND FALSE)
+      endif()
+    endif()
+
+    if(WAYLAND_FOUND)
+      execute_process(
+        COMMAND ${PKG_CONFIG_EXECUTABLE} --variable=pkgdatadir wayland-protocols
+        WORKING_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}"
+        RESULT_VARIABLE WAYLAND_PROTOCOLS_DIR_RC
+        OUTPUT_VARIABLE WAYLAND_PROTOCOLS_DIR
+        ERROR_QUIET
+        OUTPUT_STRIP_TRAILING_WHITESPACE
+      )
+      if(NOT WAYLAND_PROTOCOLS_DIR_RC EQUAL 0)
+        set(WAYLAND_FOUND FALSE)
+      endif()
+    endif()
+
+    if(WAYLAND_FOUND)
+      execute_process(
+        COMMAND ${PKG_CONFIG_EXECUTABLE} --variable=wayland_scanner wayland-scanner
+        WORKING_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}"
+        RESULT_VARIABLE WAYLAND_SCANNER_RC
+        OUTPUT_VARIABLE WAYLAND_SCANNER
+        ERROR_QUIET
+        OUTPUT_STRIP_TRAILING_WHITESPACE
+      )
+      if(NOT WAYLAND_SCANNER_RC EQUAL 0)
+        set(WAYLAND_FOUND FALSE)
+      endif()
+    endif()
+
     if(WAYLAND_FOUND)
       link_directories(
           ${WAYLAND_LIBRARY_DIRS}
@@ -561,6 +626,17 @@ macro(CheckWayland)
       file(GLOB WAYLAND_SOURCES ${SDL2_SOURCE_DIR}/src/video/wayland/*.c)
       set(SOURCE_FILES ${SOURCE_FILES} ${WAYLAND_SOURCES})
 
+      # We have to generate some protocol interface code for some unstable Wayland features.
+      file(MAKE_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/wayland-generated-protocols")
+      include_directories("${CMAKE_CURRENT_BINARY_DIR}/wayland-generated-protocols")
+
+      WaylandProtocolGen("${WAYLAND_SCANNER}" "${WAYLAND_CORE_PROTOCOL_DIR}/wayland.xml" "wayland")
+
+      foreach(_PROTL relative-pointer-unstable-v1 pointer-constraints-unstable-v1)
+        string(REGEX REPLACE "\\-unstable\\-.*$" "" PROTSUBDIR ${_PROTL})
+        WaylandProtocolGen("${WAYLAND_SCANNER}" "${WAYLAND_PROTOCOLS_DIR}/unstable/${PROTSUBDIR}/${_PROTL}.xml" "${_PROTL}")
+      endforeach()
+
       if(VIDEO_WAYLAND_QT_TOUCH)
           set(SDL_VIDEO_DRIVER_WAYLAND_QT_TOUCH 1)
       endif()