[Tarantool-patches] [PATCH v2 03/10] cmake: add option ENABLE_UB_SANITIZER

[Vladislav Shpilevoy]

Clang has a built-in sanitizer for undefined behaviour. Such as
wrong memory alignment, array boundaries violation, 0 division,
bool values with non standard content, etc.

The sanitizer emits runtime checks which lead to either crash, or
a trap, or a warning print, depending on what is chosen.

The patch makes it possible to turn the sanitizer on and catch
UBs. The only supported UB so far is alignment check. Other types
can be added gradually, along with fixing bugs which they find.

The UB sanitizer is activated for ASAN builds in CI.

Part of #4609
---
 .travis.mk           |  3 ++-
 cmake/compiler.cmake | 10 ++++++++++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/.travis.mk b/.travis.mk
index 063537f25..748321f26 100644
--- a/.travis.mk
+++ b/.travis.mk
@@ -114,7 +114,8 @@ coverage_debian: deps_debian test_coverage_debian_no_deps
 
 build_asan_debian:
 	CC=clang-8 CXX=clang++-8 cmake . -DCMAKE_BUILD_TYPE=RelWithDebInfo \
-		-DENABLE_WERROR=ON -DENABLE_ASAN=ON ${CMAKE_EXTRA_PARAMS}
+		-DENABLE_WERROR=ON -DENABLE_ASAN=ON -DENABLE_UB_SANITIZER=ON \
+		${CMAKE_EXTRA_PARAMS}
 	make -j
 
 test_asan_debian_no_deps: build_asan_debian
diff --git a/cmake/compiler.cmake b/cmake/compiler.cmake
index ce3e7e506..373bcd3b0 100644
--- a/cmake/compiler.cmake
+++ b/cmake/compiler.cmake
@@ -238,6 +238,8 @@ endif()
 
 option(ENABLE_WERROR "Make all compiler warnings into errors" OFF)
 
+option(ENABLE_UB_SANITIZER "Make the compiler generate runtime code to perform undefined behaviour checks" OFF)
+
 macro(enable_tnt_compile_flags)
     # Tarantool code is written in GNU C dialect.
     # Additionally, compile it with more strict flags than the rest
@@ -263,6 +265,14 @@ macro(enable_tnt_compile_flags)
         "-Wno-strict-aliasing"
     )
 
+    if (ENABLE_UB_SANITIZER)
+        if (NOT CMAKE_COMPILER_IS_CLANG)
+            message(FATAL_ERROR "Undefined behaviour sanitizer only available for clang")
+        else()
+            add_compile_flags("C;CXX" "-fsanitize=alignment -fno-sanitize-recover=alignment")
+        endif()
+    endif()
+
     if (CMAKE_COMPILER_IS_CLANG AND CC_HAS_WNO_UNUSED_VALUE)
         # False-positive warnings for ({ xx = ...; x; }) macroses
         add_compile_flags("C;CXX" "-Wno-unused-value")
-- 
2.21.1 (Apple Git-122.3)