cmake: interface library for sof static libraries

Target dependencies have to be added in the same CMakeLists in which
they are declared. CMake interface library is needed to enable adding
static libraries to sof target from subdirectories.

Signed-off-by: Janusz Jankowski <[email protected]>

CMakeLists.txt

@@ -61,6 +61,10 @@ add_library(sof_options INTERFACE)
 
 target_link_libraries(sof_options INTERFACE sof_public_headers)
 
+# interface library that is used only as container for sof statically
+# linked libraries
+add_library(sof_static_libraries INTERFACE)
+
 # get compiler name and version
 execute_process(
 	COMMAND ${CMAKE_C_COMPILER} --version
@@ -117,6 +121,7 @@ target_include_directories(sof_public_headers INTERFACE ${GENERATED_DIRECTORY}/i
 if(BUILD_LIBRARY)
 	add_library(sof SHARED "")
 	target_link_libraries(sof PRIVATE sof_options)
+	target_link_libraries(sof PRIVATE sof_static_libraries)
 	install(TARGETS sof DESTINATION lib)
 
 	add_subdirectory(src)
@@ -166,9 +171,8 @@ add_executable(sof "")
 target_link_libraries(sof PRIVATE sof_options)
 target_link_libraries(sof PRIVATE sof_ld_scripts)
 target_link_libraries(sof PRIVATE sof_ld_flags)
+target_link_libraries(sof PRIVATE sof_static_libraries)
 
 sof_add_build_counter_rule()
 
 add_subdirectory(src)
-
-target_link_libraries(sof PRIVATE sof_lib)

src/arch/xtensa/CMakeLists.txt

@@ -154,24 +154,21 @@ add_local_sources(sof
 	exc-dump.S
 )
 
-add_library(sof_lib INTERFACE)
-target_link_libraries(sof_lib INTERFACE sof_options)
-
 # TODO: order of these libraries does matter, what is bad,
 # we should switch to building with thin archives without symbols index
 # and made it before final link so dependencies won't matter
-target_link_libraries(sof_lib INTERFACE xtos)
-target_link_libraries(sof_lib INTERFACE hal)
+target_link_libraries(sof_static_libraries INTERFACE xtos)
+target_link_libraries(sof_static_libraries INTERFACE hal)
 
-target_link_libraries(sof_lib INTERFACE xlevel2)
-target_link_libraries(sof_lib INTERFACE xlevel3)
-target_link_libraries(sof_lib INTERFACE xlevel4)
-target_link_libraries(sof_lib INTERFACE xlevel5)
+target_link_libraries(sof_static_libraries INTERFACE xlevel2)
+target_link_libraries(sof_static_libraries INTERFACE xlevel3)
+target_link_libraries(sof_static_libraries INTERFACE xlevel4)
+target_link_libraries(sof_static_libraries INTERFACE xlevel5)
 
 if(build_bootloader)
 	add_local_sources(sof main-entry.S)
 else()
-	target_link_libraries(sof_lib INTERFACE reset)
+	target_link_libraries(sof_static_libraries INTERFACE reset)
 endif()
 
 target_link_libraries(sof_ld_flags INTERFACE "-lgcc")