Index: cfe/trunk/tools/clang-shlib/CMakeLists.txt =================================================================== --- cfe/trunk/tools/clang-shlib/CMakeLists.txt +++ cfe/trunk/tools/clang-shlib/CMakeLists.txt @@ -7,8 +7,35 @@ foreach (lib ${clang_libs}) list(APPEND _OBJECTS $) - list(APPEND _DEPS $) - list(APPEND _DEPS $) + # Use the static library for its dependencies. The objects that constitute the + # static library will appear on the link line before the library, so it'll + # just be ignored, but the dependencies of the library will still be linked + # correctly. + # + # We could propagate the dependencies manually using the library's + # INTERFACE_LINK_LIBRARIES property, but that will contain $ + # generator expressions if a static library has a private dependency, so we + # can't use a $ generator expression to get the property + # (since it wouldn't evaluate any generator expressions inside the property). + # We could use get_property and do string manipulation to manually evaluate + # the $, but that would miss any dependencies added after we + # evaluate the get_property. We could also use the LINK_LIBRARIES property + # instead, which should be free of any generator expressions, but that's + # technically incorrect (it'd most likely work fine in practice, but still). + # + # Another alternative would be to use --whole-archive or equivalent instead of + # using the object library at all. However, CMake reorders static libraries on + # the link line so that a library appears after all its dependents, which can + # reorder static libraries out of their --whole-archive --no-whole-archive + # sandwich. It's really hard to avoid that reordering while still propagating + # dependencies, which defeats the whole point. + # + # The ideal solution here is to bump our minimum CMake requirement to 3.12, + # which adds support for dependencies on object libraries. Until then, linking + # both the object and the static libraries seems like the least bad solution. + # + # TODO: Rework this when we bump our minimum CMake version to 3.12 or newer. + list(APPEND _DEPS ${lib}) endforeach () add_clang_library(clang_shared