In Visual Studio 2019 version 16.1, AddressSanitizer (ASan) support is integrated into Linux projects. You can enable ASan for both MSBuild-based Linux projects and CMake projects. It works on remote Linux systems and on Windows Subsystem for Linux (WSL).

ASan is a runtime memory error detector for C/C++ that catches the following errors:

• Use after free (dangling pointer reference)
• Heap buffer overflow
• Stack buffer overflow
• Use after return
• Use after scope
• Initialization order bugs

When ASan detects an error, it stops execution immediately. If you run an ASan-enabled program in the debugger, you see a message that describes the type of error, the memory address, and the location in the source file where the error occurred:

You can also view the full ASan output (including where the corrupted memory was allocated/deallocated) in the Debug pane of the output window.

To enable ASan for MSBuild-based Linux projects, right-click on the project in Solution Explorer and select Properties. Next, navigate to Configuration Properties > C/C++ > Sanitizers. ASan is enabled via compiler and linker flags, and requires your project to be recompiled to work.

You can pass optional ASan runtime flags by navigating to Configuration Properties > Debugging > AddressSanitizer Runtime Flags. Click the down arrow to add or remove flags.

To enable ASan for CMake, right-click on the CMakeLists.txt file in Solution Explorer and choose CMake Settings for Project.

Make sure you have a Linux configuration (for example, Linux-Debug) selected in the left pane of the dialog:

The ASan options are under General. Enter the ASan runtime flags in the format "flag=value", separated by semicolons.

To enable the ASan diagnostics, you must install its debug symbols (libasan-dbg) on your remote Linux machine or WSL installation. The version of libasan-dbg that you load depends on the version of GCC installed on your Linux machine:

You can determine which version of GCC you have by using this command:

gcc --version

To view the version of libasan-dbg you need, run your program, and then look at the Debug pane of the Output window. The version of ASan that's loaded corresponds to the version of libasan-dbg needed on your Linux machine. You can use Ctrl + F to search for "libasan" in the window. If you have libasan4, for example, you see a line like this:

Loaded '/usr/lib/x86_64-linux-gnu/libasan.so.4'. Symbols loaded.

You can install the ASan debug bits on Linux distros that use apt with the following command. This command installs version 4:

sudo apt-get install libasan4-dbg

If ASan is enabled, Visual Studio prompts you at the top of the Debug pane of the Output window to install the ASan debug symbols.