Make clang -fsanitize an option and fix setup script to add sanitize …

…flag for clang

CMakeLists.txt

@@ -20,6 +20,10 @@ option(FLATCC_TEST "enable tests" ON)
 # project.
 option(FLATCC_CXX_TEST "enable C++ tests" ON)
 
+# Note that linking with flatcc debug libraries may require souce code to also use
+# the sanitize flag.
+option(FLATCC_DEBUG_CLANG_SANITIZE "enable clang sanitize flag for debug build" ON)
+
 # Conditionally set project languages based on FLATCC_TEST, as C++ is
 # only necessary if building the tests.
 if (FLATCC_TEST AND FLATCC_CXX_TEST)
@@ -188,9 +192,11 @@ if (CMAKE_C_COMPILER_ID MATCHES "Clang" AND NOT "${CMAKE_CXX_SIMULATE_ID}" STREQ
     if (FLATCC_IGNORE_CONST_COND)
         set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-tautological-constant-out-of-range-compare")
     endif()
-    if (CMAKE_BUILD_TYPE MATCHES Debug)
-        set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fsanitize=undefined")
-        set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fsanitize=undefined")
+    if (FLATCC_DEBUG_CLANG_SANITIZE)
+        if (CMAKE_BUILD_TYPE MATCHES Debug)
+            set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fsanitize=undefined")
+            set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fsanitize=undefined")
+        endif()
     endif()
     # Suppress warning relaxed in clang-6, see https://reviews.llvm.org/D28148
     if (CMAKE_C_COMPILER_VERSION VERSION_LESS 6)

README.md

@@ -294,6 +294,13 @@ fi
 
 ## Status
 
+Release 0.6.2 (in development) is primarily a bug fix release, refer
+to CHANGELOG for details.
+Note that for clang debug builds, -fsanitize=undefined has been
+added and this may require dependent source code to also use
+that flag to avoid missing linker symbols. The feature can be disabled
+in CMakeLists.txt.
+
 Release 0.6.1 contains primarily bug fixes and numerous contributions
 from the community to handle platform edge cases. Additionally,
 pendantic GCC warnings are disabled, relying instead on clang, since GCC
@@ -390,6 +397,11 @@ different target platforms.
 
 ### Supported platforms (CI tested)
 
+This list is somewhat outdated, more recent compiler versions are added and
+some old ones are removed when CI platforms no longer supported but largely
+the supported targets remain unchanged. MSVC 2010 might become deprecated
+in the future.
+
 The ci-more branch tests additional compilers:
 
 - Ubuntu Trusty gcc 4.4, 4.6-4.9, 5, 6, 7 and clang 3.6, 3.8

scripts/_user_build.in

@@ -15,12 +15,21 @@ mkdir -p generated
 
 cd build
 
+# we cannot link with debug library unless we use the sanitize flag.
+SANFLAG_DEBUG=""
+compiler_info="$($CC --version 2>&1)"
+echo "using compiler: $compiler_info"
+if echo $compiler_info | grep -q -i "clang"; then
+    SANFLAG_DEBUG="-fsanitize=undefined"
+    echo "sanitizer flag: $SANFLAG_DEBUG"
+fi
+
 if [[ "$FLATCC_PORTABLE" = "yes" ]]; then
     CFLAGS="$CFLAGS -DFLATCC_PORTABLE"
 fi
 
 CFLAGS="$CFLAGS -I ${ROOT}/include -I ${ROOT}/generated"
-CFLAGS_DEBUG=${CFLAGS_DEBUG:--g}
+CFLAGS_DEBUG=${CFLAGS_DEBUG:--g $SANFLAG_DEBUG}
 CFLAGS_RELEASE=${CFLAGS_RELEASE:--O2 -DNDEBUG}
 
 ${ROOT}/bin/flatcc -a -o ${ROOT}/generated ${ROOT}/src/*.fbs
@@ -30,3 +39,5 @@ $CC $CFLAGS $CFLAGS_DEBUG ${ROOT}/src/*.c ${ROOT}/lib/libflatccrt_d.a -o ${NAME}
 
 echo "building '$NAME' for release"
 $CC $CFLAGS $CFLAGS_RELEASE ${ROOT}/src/*.c ${ROOT}/lib/libflatccrt.a -o ${NAME}
+
+echo using compiler $CC