Added option to enable UndefinedBehaviorSanitizer on Clang and GCC.

deps/Boost/Boost.cmake

@@ -120,6 +120,12 @@ set(_build_cmd ${_build_cmd}
 
 set(_install_cmd ${_build_cmd} --prefix=${_prefix} install)
 
+if (CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
+    # When Clang is used with enabled UndefinedBehaviorSanitizer, it produces "undefined reference to '__muloti4'" when __int128 is used.
+    # Because of that, UndefinedBehaviorSanitizer is disabled for those functions that use __int128.
+    list(APPEND _patch_command COMMAND ${PATCH_CMD} ${CMAKE_CURRENT_LIST_DIR}/Boost.patch)
+endif ()
+
 ExternalProject_Add(
     dep_Boost
     URL "https://boostorg.jfrog.io/artifactory/main/release/1.75.0/source/boost_1_75_0.tar.gz"

deps/Boost/Boost.patch

@@ -0,0 +1,23 @@
+diff -u ../boost_1_75_0-orig/boost/rational.hpp ./boost/rational.hpp
+--- ../boost_1_75_0-orig/boost/rational.hpp	2020-12-03 06:02:19.000000000 +0100
++++ ./boost/rational.hpp	2022-01-27 16:02:27.993848905 +0100
+@@ -302,6 +302,9 @@
+        return *this;
+     }
+     template <class T>
++    #if defined(__clang__)
++    __attribute__((no_sanitize("undefined")))
++    #endif
+     BOOST_CXX14_CONSTEXPR typename boost::enable_if_c<rational_detail::is_compatible_integer<T, IntType>::value, rational&>::type operator*= (const T& i)
+     {
+        // Avoid overflow and preserve normalization
+@@ -311,6 +314,9 @@
+        return *this;
+     }
+     template <class T>
++    #if defined(__clang__)
++    __attribute__((no_sanitize("undefined")))
++    #endif
+     BOOST_CXX14_CONSTEXPR typename boost::enable_if_c<rational_detail::is_compatible_integer<T, IntType>::value, rational&>::type operator/= (const T& i)
+     {
+        // Avoid repeated construction