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

Question

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")

cmake 3.13
introduce configuration for xcode schema

in CMake

cmake_minimum_required(VERSION 3.13)
set(CMAKE_XCODE_GENERATE_SCHEME ON)
set(CMAKE_XCODE_SCHEME_ADDRESS_SANITIZER ON)
set(CMAKE_XCODE_SCHEME_ADDRESS_SANITIZER_USE_AFTER_RETURN ON)

When Build

xcodebuild -enableAddressSanitizer YES

I propose create your own Asan profile.

get_property(isMultiConfig GLOBAL PROPERTY GENERATOR_IS_MULTI_CONFIG)

if(isMultiConfig)
    if(NOT "Asan" IN_LIST CMAKE_CONFIGURATION_TYPES)
        list(APPEND CMAKE_CONFIGURATION_TYPES Asan)
    endif()
else()
    set(allowedBuildTypes Asan Debug Release RelWithDebInfo MinSizeRel)
    set_property(CACHE CMAKE_BUILD_TYPE PROPERTY STRINGS "${allowedBuildTypes}")

    if(CMAKE_BUILD_TYPE AND NOT CMAKE_BUILD_TYPE IN_LIST allowedBuildTypes)
        message(FATAL_ERROR "Invalid build type: ${CMAKE_BUILD_TYPE}")
    endif()
endif()

set(CMAKE_C_FLAGS_ASAN
    "${CMAKE_C_FLAGS_DEBUG} -fsanitize=address -fno-omit-frame-pointer" CACHE STRING
    "Flags used by the C compiler for Asan build type or configuration." FORCE)

set(CMAKE_CXX_FLAGS_ASAN
    "${CMAKE_CXX_FLAGS_DEBUG} -fsanitize=address -fno-omit-frame-pointer" CACHE STRING
    "Flags used by the C++ compiler for Asan build type or configuration." FORCE)

set(CMAKE_EXE_LINKER_FLAGS_ASAN
    "${CMAKE_SHARED_LINKER_FLAGS_DEBUG} -fsanitize=address" CACHE STRING
    "Linker flags to be used to create executables for Asan build type." FORCE)

set(CMAKE_SHARED_LINKER_FLAGS_ASAN
    "${CMAKE_SHARED_LINKER_FLAGS_DEBUG} -fsanitize=address" CACHE STRING
    "Linker lags to be used to create shared libraries for Asan build type." FORCE)

Notes:

1. AddressSanitizer (ASan) for Windows with MSVC is under experimental stage thus I didn't provided the MSVC way here.

2. CMAKE_BUILD_TYPE isn't used by multi-configuration generators (Xcode, Visual Studio, etc), thus I provided an example to check this first.

3. The default value for CMAKE_BUILD_TYPE is an empty string. And user can set CMAKE_BUILD_TYPE to any value at the cmake command line. Therefore, we check both cases, and make sure that we are dealing with a known build type (if provided).

4. There is also CMAKE_MODULE_LINKER_FLAGS you may want to configure.

Usage:

$ cmake \
    -DCMAKE_BUILD_TYPE=Asan \
    ...
    ...

Since the top-voted answer is the wrong way to do it these days and I did not get the proper cmake solution for this reading this thread, I thought I would mention the correct way at the time of writing this so that the next reader does not need to spend much time with this. Hope it helps.

The idea of this solution is to pass -fsanitize=address to the compiler and linker flags.

If you would like to enable this for all your targets at the same time, you can use add_compile_options and add_link_options. This makes sense if you have multiple, potentially a large of, targets.

add_compile_options(-fsanitize=address)
add_link_options(-fsanitize=address)

Alternatively, you can also use target_compile_options and target_link_options to set these for a particular target. This might make more sense if you do not want this to apply to all the targets.

target_compile_options(asan-target PRIVATE -fsanitize=address)
target_link_options(asan-target PRIVATE -fsanitize=address)