topology2: add SYMLINKS support for production topologies

Some topologies are byte-for-byte identical to an existing one and
only need to be reachable under a different name. Add a SYMLINKS
list, processed alongside TPLGS in production/CMakeLists.txt, that
creates a real symlink instead of building a duplicate topology.

cmake -E copy_if_different dereferences symlinks when deploying the
build output, turning them back into regular file copies. Switch to
"cp -a" so the deploy step preserves symlinks as symlinks.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>

Author: ujfalusi

tools/topology/topology2/CMakeLists.txt

@@ -8,9 +8,9 @@ add_custom_target(topologies2 ALL
     COMMAND ${CMAKE_COMMAND} -E make_directory ${CMAKE_CURRENT_BINARY_DIR}/target/sof-ipc4-tplg
     COMMAND ${CMAKE_COMMAND} -E create_symlink sof-ipc4-tplg ${CMAKE_CURRENT_BINARY_DIR}/target/sof-ace-tplg
     COMMAND ${CMAKE_COMMAND} -E make_directory ${CMAKE_CURRENT_BINARY_DIR}/target/development
-    # copy the topology files only to target
-    COMMAND ${CMAKE_COMMAND} -E copy_if_different production/*.tplg ${CMAKE_CURRENT_BINARY_DIR}/target/sof-ipc4-tplg/
-    COMMAND ${CMAKE_COMMAND} -E copy_if_different development/*.tplg ${CMAKE_CURRENT_BINARY_DIR}/target/development/
+    # copy the topology files only to target, preserving symbolic links
+    COMMAND sh -c "cp -a production/*.tplg \"${CMAKE_CURRENT_BINARY_DIR}/target/sof-ipc4-tplg/\""
+    COMMAND sh -c "cp -a development/*.tplg \"${CMAKE_CURRENT_BINARY_DIR}/target/development/\""
 )
 
 # Check alsatplg version and build topology2 if alsatplg version is

tools/topology/topology2/production/CMakeLists.txt

@@ -32,3 +32,23 @@ foreach(tplg ${TPLGS})
 	add_custom_target(topology2_prod_${output} DEPENDS ${output}.tplg)
 	add_dependencies(topology2_prod topology2_prod_${output})
 endforeach()
+
+foreach(link ${SYMLINKS})
+	list(LENGTH link length)
+	if(NOT length EQUAL 2)
+		message(FATAL_ERROR "SYMLINKS entry '${link}' must have exactly 2 elements (link_name;link_target), got ${length}")
+	endif()
+
+	list(GET link 0 link_name)
+	list(GET link 1 link_target)
+
+	add_custom_command(
+		OUTPUT ${link_name}.tplg
+		COMMAND ${CMAKE_COMMAND} -E create_symlink "${link_target}.tplg" "${link_name}.tplg"
+		DEPENDS ${link_target}.tplg
+		VERBATIM
+	)
+
+	add_custom_target(topology2_prod_${link_name} DEPENDS ${link_name}.tplg)
+	add_dependencies(topology2_prod topology2_prod_${link_name})
+endforeach()