Add a cmake option to build with sanitizers

Disabled by default, only for debugging.

When using it it may be required to manually preload:
`LD_PRELOAD=/usr/lib64/libasan.so.8` for the client process.
This is because ASan runtime requires to be first in initial library list.

CMakeLists.txt

@@ -9,6 +9,7 @@ OPTION (ENABLE_PYTHON "Build Python bindings" ON)
 OPTION (USE_GPGME "Use GpgMe (instead of rpm library) for OpenPGP key support" ON)
 OPTION (USE_RUN_GNUPG_USER_SOCKET "Create a directory for gpg-agent socket in /run/gnugp/user (instead of /run/user)" OFF)
 OPTION (ENABLE_SELINUX "Restore SELinux labels on GnuPG directories" ON)
+OPTION (WITH_SANITIZERS "Build with address, leak and undefined sanitizers (DEBUG ONLY)" OFF)
 
 INCLUDE (${CMAKE_SOURCE_DIR}/VERSION.cmake)
 SET (VERSION "${LIBREPO_MAJOR}.${LIBREPO_MINOR}.${LIBREPO_PATCH}")
@@ -95,6 +96,12 @@ IF (NOT CURL_FOUND)
     MESSAGE(FATAL_ERROR "No CURL library installed")
 ENDIF (NOT CURL_FOUND)
 
+IF (WITH_SANITIZERS)
+    MESSAGE(WARNING "Building with sanitizers enabled!")
+    ADD_COMPILE_OPTIONS(-fsanitize=address -fsanitize=undefined -fsanitize=leak)
+    LINK_LIBRARIES(asan ubsan)
+ENDIF()
+
 # Generate header files with the configured ABI (e.g. with/without zchunk).
 
 configure_file("librepo/downloadtarget.h.in" "librepo/downloadtarget.h" @ONLY)

librepo.spec

@@ -19,6 +19,8 @@
 # Needs to match how gnupg2 is compiled
 %bcond_with run_gnupg_user_socket
 
+%bcond_without sanitizers
+
 %if %{with use_gpgme} && %{with use_selinux}
 %global need_selinux 1
 %else
@@ -59,6 +61,12 @@ BuildRequires:  pkgconfig(zck) >= 0.9.11
 %endif
 Requires:       libcurl%{?_isa} >= %{libcurl_version}
 
+%if %{with sanitizers}
+BuildRequires:  libasan
+BuildRequires:  liblsan
+BuildRequires:  libubsan
+%endif
+
 %description
 A library providing C and Python (libcURL like) API to downloading repository
 metadata.
@@ -97,6 +105,7 @@ Python 3 bindings for the librepo library.
     -DWITH_ZCHUNK=%{?with_zchunk:ON}%{!?with_zchunk:OFF} \
     -DUSE_GPGME=%{?with_use_gpgme:ON}%{!?with_use_gpgme:OFF} \
     -DUSE_RUN_GNUPG_USER_SOCKET=%{?with_run_gnupg_user_socket:ON}%{!?with_run_gnupg_user_socket:OFF} \
+    -DWITH_SANITIZERS=%{?with_sanitizers:ON}%{!?with_sanitizers:OFF} \
 %if %{need_selinux}
     -DENABLE_SELINUX=ON
 %else