In MSVC if I do this with address sanitizer turned on I get a runtime exception:

#include <vector>

    int main()
    {
    
    
        std::vector<int> my_vector;
        my_vector.reserve(20);
        my_vector.assign({ 1, 1, 1 });
        int* p = my_vector.data();
        std::cout << p[3];
    /*ERROR: AddressSanitizer: container-overflow on address 0x11d4a44ebf1c at pc 0x7ff6a882ae53 bp 0x0020d85cf720 sp 0x0020d85cf728
    READ of size 4 at 0x11d4a44ebf1c thread T0*/
    }

HINT: if you don't care about these errors you may set ASAN_OPTIONS=detect_container_overflow=0.
If you suspect a false positive see also: https://github.com/google/sanitizers/wiki/AddressSanitizerContainerOverflow.

I took me a while to figure out that this command is supposed to go in Environment variables under the “Debugging” menu. What I don’t get is that ASAN isn’t just a debug thing. For example I can run it in Release mode with the sanitizer on, why is it that ASAN_OPTIONS=detect_container_overflow=0 must be passed as a debugging environment variable? At first I thought it was supposed to be passed to the compiler options or as a preprocessor definition or something.

Is there a way to set this in CMake? I’ve tried:

set(ENV{ASAN_OPTIONS} "detect_container_overflow=0")

My CMake:

if (CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
    message("Using GCC compiler")
elseif (CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
    message("Using Clang compiler")
elseif (CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
    message("Using MSVC compiler")
    add_compile_options(
        /MP # MULTIPROCESSOR COMPILE 
        /Oi # ENABLE COMPILER INTRINSICS
        /utf-8
        $<$<CONFIG:DEBUG>:/fsanitize=address>
        $<$<CONFIG:DEBUG>:/fsanitize=fuzzer> 
        
    ) 
    set(ENV{ASAN_OPTIONS} "detect_container_overflow=0") # SET THIS BECAUSE SHADERC THROWS A FALSE POSITIVE ERROR BECAUSE THE LIBRARY WASN'T COMPILED WITH SANITIZER ON 

else ()
    message("Unknown compiler: ${CMAKE_CXX_COMPILER_ID}")
endif ()

This has no effect on the ASAN flags, so it’s not going into the right place.