Add a switch to enable the undefined behavior sanitizer

3 files changed, 30 insertions, 1 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 1925b9b..57a2a0c 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -78,6 +78,12 @@ if(ASAN_AVAILABLE)
 	    CACHE BOOL "Enable GCC/LLVM run-time stack/pointer debugging (~2x slowdown)")
 endif(ASAN_AVAILABLE)
 
+CHECK_C_COMPILER_FLAG("-fsanitize=undefined" UBSAN_AVAILABLE)
+if(UBSAN_AVAILABLE)
+	set(ENABLE_UBSAN 0
+	    CACHE BOOL "Enable GCC/LLVM run-time undefined behavior debugging")
+endif(UBSAN_AVAILABLE)
+
 find_program(GZIP gzip)
 if(UNIX AND GZIP)
 	set(ENABLE_MAN_PAGES 1 CACHE BOOL "Built and install man pages")
@@ -243,6 +249,15 @@ if(ENABLE_ASAN)
 	set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fsanitize=address -fno-common")
 endif(ENABLE_ASAN)
 
+# GCC/Clang undefined behavior debugging
+if(ENABLE_UBSAN)
+	# We assume twos-complement of modern CPUs, so use -fwrapv to
+	# silence related ubsan warnings:
+	set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fsanitize=undefined -fwrapv")
+	add_definitions(-DENABLE_UBSAN=1)
+endif(ENABLE_UBSAN)
+
+
 # GCC/Clang specific flags:
 if(CMAKE_COMPILER_IS_GNUCC OR CMAKE_C_COMPILER_ID MATCHES "Clang")
 	# We want to allow ‘for’-loop initial declarations a la for(int i=0; ...)
diff --git a/configure b/configure
index ee6706a..a4e7110 100755
--- a/configure
+++ b/configure
@@ -14,10 +14,12 @@ print_help()
   echo "This is a simple configure script wrapper around cmake build system."
   echo "Parameters are:"
   echo "  --prefix=<path>            Set the install prefix to path"
+  echo "  --enable-asan              Enable address sanitizer debug build"
   echo "  --enable-debug             Enable debug (non-optimized) build"
   echo "  --disable-dsp              Disable DSP emulation for Falcon mode."
   echo "  --disable-tracing          Disable tracing messages for debugging"
   echo "  --disable-osx-bundle       Disable application bundling on macOS"
+  echo "  --enable-ubsan             Enable undefined behavior sanitizer debug build"
   echo "  --enable-werror            Use -Werror flag to stop on compiler warnings"
   echo "  --cross-compile-win64_32   Build the 32 bit Windows version using mingw-w64"
   echo "  --cross-compile-win64_64   Build the 64 bit Windows version using mingw-w64"
@@ -42,6 +44,12 @@ do
       prefix=${1##*=}		# get part after =
       cmake_args="$cmake_args -DCMAKE_INSTALL_PREFIX:PATH=$prefix"
     ;;
+    --enable-asan)
+      cmake_args="$cmake_args -DENABLE_ASAN:BOOL=1"
+    ;;
+    --disable-asan)
+      cmake_args="$cmake_args -DENABLE_ASAN:BOOL=0"
+    ;;
     --enable-debug)
       build_type="Debug"
       cmake_args="$cmake_args -DCMAKE_BUILD_TYPE:STRING=Debug"
@@ -68,6 +76,12 @@ do
     --disable-osx-bundle)
       cmake_args="$cmake_args -DENABLE_OSX_BUNDLE:BOOL=0"
     ;;
+    --enable-ubsan)
+      cmake_args="$cmake_args -DENABLE_UBSAN:BOOL=1"
+    ;;
+    --disable-ubsan)
+      cmake_args="$cmake_args -DENABLE_UBSAN:BOOL=0"
+    ;;
     --enable-werror)
       cmake_args="$cmake_args -DENABLE_WERROR:BOOL=1"
     ;;
diff --git a/src/cpu/maccess.h b/src/cpu/maccess.h
index b53a7e6..0eb9c08 100644
--- a/src/cpu/maccess.h
+++ b/src/cpu/maccess.h
@@ -39,7 +39,7 @@
 #endif
 
 /* If the CPU can access unaligned memory, use these accelerated functions: */
-#if CPU_CAN_ACCESS_UNALIGNED
+#if CPU_CAN_ACCESS_UNALIGNED && !defined(ENABLE_UBSAN)
 
 static inline uae_u32 do_get_mem_long(void *a)
 {