Add CMake option to enable address sanitizers

Signed-off-by: Felix Weilbach <felix.weilbach@nextcloud.com>

1 files changed, 30 insertions, 0 deletions

diff --git a/doc/building.rst b/doc/building.rst
index 31c82b737..1d7df6889 100644
--- a/doc/building.rst
+++ b/doc/building.rst
@@ -373,6 +373,36 @@ The following are known cmake parameters:
 * ``BUILD_WITH_QT4=ON``: Builds using Qt4 (even if Qt5 is found).
 * ``CMAKE_INSTALL_PREFIX=path``: Set an install prefix. This is mandatory on Mac OS
 
+Address Sanitizer
+=================
+
+You can enable the address sanitizer to detect memory corruptions and other mistakes.
+The are the follwing sanitizers are available:
+- Address Sanitizer (ENABLE_SANITIZER_ADDRESS)
+- Leak anitizer (ENABLE_SANITIZER_LEAK)
+- Memory sanitizer (ENABLE_SANITIZER_MEMORY)
+- Undefined sanitizer (ENABLE_SANITIZER_UNDEFINED)
+- Threads sanitizer (ENABLE_SANITIZER_THREAD)
+
+You can enable one or more sanitizers through CMake. For example to
+enable the address and the undefined sanitizer, execute CMake like
+``cmake .. -D ENABLE_SANITIZER_ADDRESS=ON -D ENABLE_SANITIZER_UNDEFINED=ON``.
+Keep in mind that not all combinations of sanitizers work together and on some
+platforms not all types of sanitizers are available. For example on Windows there is
+currently only the address sanitizer available. If you are on Windows, you need to
+make sure that the linker can find the sanitizer dlls at runtime. If you installed
+Visual Studio in the standard location, you can find them in
+``C:/ProgramFiles (x86)/Microsoft Visual Studio/2019/Community/VC/Tools/Llvm/x64/lib/clang/10.0.0/lib/windows``.
+Make sure you add this location to your path. You may also need to
+`upgrade your Visual Studio version <https://docs.microsoft.com/en-us/cpp/sanitizers/asan?view=msvc-160#install-the-addresssanitizer>`_.
+
+.. note:: If you use Visual Studio on Windows, you can enable the
+          sanitizer if you click on **Manage Configurations**, scroll
+          down to the section **CMake variables and cache** and then
+          click on the sanitizers that you want to enable. After that,
+          click on **Save and generate CMake cache to load variables**
+          right above the table.
+
 .. _CMake: http://www.cmake.org/download
 .. _CSync: http://www.csync.org
 .. _Client Download Page: https://nextcloud.com/install/#install-clients