Compiler warning flags for all except ExternalProjects

[ben.boeckel (Ben Boeckel (Kitware))]

You can make a target that carries the flags and you link to from each of your targets (either manually or via something like looping over BUILDSYSTEM_TARGETS):

Setting `CMAKE_CXX_FLAGS` within a function

Note that the better solution these days is something like: add_library(buildflags INTERFACE) target_compile_options(buildflags INTERFACE -Wsome-warning) # For each target target_link_libraries(mytgt PRIVATE buildflags)