Fix absl link for libwebrtcbuild

Author: ilya-fedin

cmake/external.cmake

@@ -98,12 +98,17 @@ endfunction()
 # libabsl
 # HINT: System abseil should be built with -DCMAKE_CXX_STANDARD=20
 function(link_libabsl target_name)
+    set(scope PRIVATE)
+    get_target_property(target_type ${target_name} TYPE)
+    if (${target_type} STREQUAL "INTERFACE_LIBRARY")
+        set(scope INTERFACE)
+    endif()
     if (TG_OWT_PACKAGED_BUILD)
         find_package(absl)
         set(absl_FOUND ${absl_FOUND} PARENT_SCOPE)
         if (absl_FOUND)
             target_link_libraries(${target_name}
-            PUBLIC
+            ${scope}
                 absl::algorithm_container
                 absl::bind_front
                 absl::config
@@ -123,7 +128,7 @@ function(link_libabsl target_name)
         endif()
     endif()
     if (NOT absl_FOUND)
-        target_link_libraries(${target_name} PRIVATE tg_owt::libabsl)
+        target_link_libraries(${target_name} ${scope} tg_owt::libabsl)
     endif()
 endfunction()
 

cmake/libwebrtcbuild.cmake

@@ -5,9 +5,7 @@ target_link_libraries(libwebrtcbuild
 INTERFACE
     tg_owt::libyuv
 )
-if (NOT absl_FOUND)
-    target_link_libraries(libwebrtcbuild INTERFACE tg_owt::libabsl)
-endif()
+link_libabsl(libwebrtcbuild)
 
 target_compile_definitions(libwebrtcbuild
 INTERFACE