What's the proper way to enable AddressSanitizer in CMake that works in Xcode

Question

I've added AddressSanitizer flag as follow:

set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fsanitize=address")

Everything builds and runs fine when using Unix Makefiles.

The problem comes when generating the Xcode project, it just doesn't want to link because it cannot find the ASan library.

I already found two solutions, but decided not to use them because they cannot be automated using just CMake:

1. Adding -Wl,-undefined,dynamic_lookup to the linked flags, so it skips linking to dynamic libraries.
2. Link with libclang_rt.asan_osx_dynamic.dylib directly.

So what's the problem with these two solutions?

• When using solution #1, I have to manually open the target scheme in Xcode and add DYLD_INSERT_LIBRARIES environment variable pointing to libclang_rt.asan_osx_dynamic.dylib.
• When using solution #2, the path for the ASan library varies between computers.

Additionally as another solution, I tried enabling Address Sanitizer flag from the Xcode target scheme but interestingly it didn't detect the issues I added, so I didn't list this as a solution because it failed my test.

Any help will be much appreciated.

Answer 1

You need to provide the flag(s) to the linker too. I'm doing it like this:

set (CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -fno-omit-frame-pointer -fsanitize=address")
set (CMAKE_LINKER_FLAGS_DEBUG "${CMAKE_LINKER_FLAGS_DEBUG} -fno-omit-frame-pointer -fsanitize=address")