waf: added --ubsan and --ubsan-abort options

Tools/ardupilotwaf/ardupilotwaf.py

@@ -582,6 +582,14 @@ Address Sanitizer support llvm-symbolizer is required to be on the PATH.
 This option is only supported on macOS versions of clang.
 ''')
 
+    g.add_option('--ubsan',
+        action='store_true',
+        help='''Build using the gcc undefined behaviour sanitizer''')
+
+    g.add_option('--ubsan-abort',
+        action='store_true',
+        help='''Build using the gcc undefined behaviour sanitizer and abort on error''')
+    
 def build(bld):
     bld.add_pre_fun(_process_build_command)
     bld.add_pre_fun(_select_programs_from_group)

Tools/ardupilotwaf/boards.py

@@ -557,6 +557,21 @@ class sitl(Board):
             '-Werror=float-equal'
         ]
 
+        if cfg.options.ubsan or cfg.options.ubsan_abort:
+            env.CXXFLAGS += [
+                "-fsanitize=undefined",
+                "-fsanitize=float-cast-overflow",
+            ]
+            env.LINKFLAGS += [
+                "-fsanitize=undefined",
+                "-lubsan",
+            ]
+
+        if cfg.options.ubsan_abort:
+            env.CXXFLAGS += [
+                "-fno-sanitize-recover"
+            ]
+
         if not cfg.env.DEBUG:
             env.CXXFLAGS += [
                 '-O3',