From b588aee2c8e1e0c6fa8cbaa00a700c86f1a01192 Mon Sep 17 00:00:00 2001
From: Vitaly Lipatov <lav@altlinux.ru>
Date: Sun, 4 Jul 2021 18:41:32 +0300
Subject: [PATCH] include cmake rules for third party libraries only if it
 needed

---
 CMakeLists.txt       |  7 -------
 cmake/external.cmake | 15 +++++++++++++++
 2 files changed, 15 insertions(+), 7 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index f5696edba..a9e1f7aad 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -63,17 +63,10 @@ include(cmake/init_target.cmake)
 include(cmake/generate_target.cmake)
 include(cmake/target_yasm_sources.cmake)
 include(cmake/external.cmake)
-include(cmake/libabsl.cmake)
-include(cmake/libopenh264.cmake)
 include(cmake/libpffft.cmake)
 include(cmake/librnnoise.cmake)
 include(cmake/libsrtp.cmake)
-include(cmake/libusrsctp.cmake)
-include(cmake/libvpx.cmake)
 include(cmake/libyuv.cmake)
-if (NOT WIN32 AND NOT APPLE)
-    include(cmake/libevent.cmake)
-endif()
 if (APPLE)
     include(cmake/libsdkmacos.cmake)
 endif()
diff --git a/cmake/external.cmake b/cmake/external.cmake
index 03e2d259c..82510f2ed 100644
--- a/cmake/external.cmake
+++ b/cmake/external.cmake
@@ -117,6 +117,9 @@ function(link_libabsl target_name)
         endif()
     endif()
     if (NOT absl_FOUND)
+        if (NOT TARGET libabsl)
+            include(cmake/libabsl.cmake)
+        endif()
         target_link_libraries(${target_name} PRIVATE tg_owt::libabsl)
     endif()
 endfunction()
@@ -133,6 +136,9 @@ function(link_libopenh264 target_name)
         endif()
     endif()
     if (NOT LIBOPENH264_FOUND)
+        if (NOT TARGET libopenh264)
+            include(cmake/libopenh264.cmake)
+        endif()
         target_link_libraries(${target_name} PRIVATE tg_owt::libopenh264)
         target_include_directories(${target_name} PRIVATE ${libopenh264_loc}/include)
     endif()
@@ -150,6 +156,9 @@ function(link_libusrsctp target_name)
         endif()
     endif()
     if (NOT LIBUSRSCTP_FOUND)
+        if (NOT TARGET libusrsctp)
+            include(cmake/libusrsctp.cmake)
+        endif()
         target_link_libraries(${target_name} PRIVATE tg_owt::libusrsctp)
     endif()
 endfunction()
@@ -166,6 +175,9 @@ function(link_libvpx target_name)
         endif()
     endif()
     if (NOT LIBVPX_FOUND)
+        if (NOT TARGET libvpx)
+            include(cmake/libvpx.cmake)
+        endif()
         target_link_libraries(${target_name} PRIVATE tg_owt::libvpx)
         if (is_x86 OR is_x64)
             target_link_libraries(${target_name}
@@ -193,6 +205,9 @@ function(link_libevent target_name)
         endif()
     endif()
     if (NOT LIBEVENT_FOUND)
+        if (NOT TARGET libevent)
+            include(cmake/libevent.cmake)
+        endif()
         target_link_libraries(${target_name} PRIVATE tg_owt::libevent)
     endif()
 endfunction()