[[ Cleanup ]] libscript: Disable offsetof warnings for pickle macros.

peter-b · peter-b · commit 93e0a0ef78c7 · 2014-12-30T09:23:20.000Z
Officially, we're invoking undefined behaviour, but since it works for
compilers that we support ignore the warnings.
diff --git a/libscript/src/script-module.cpp b/libscript/src/script-module.cpp
@@ -31,6 +31,14 @@
 
 ////////////////////////////////////////////////////////////////////////////////
 
+/* Using offsetof() on a non-POD type (e.g. structs with inheritance
+ * and classes) is, strictly-speaking, undefined according to the C++
+ * standard (because C++'s offsetof is only present for C
+ * compatibility and is only defined for operations on C types).
+ * Disable GCC's offsetof warnings for these macros */
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Winvalid-offsetof"
+
 MC_PICKLE_BEGIN_RECORD(MCScriptDefinedType)
     MC_PICKLE_UINDEX(index)
 MC_PICKLE_END_RECORD()
@@ -177,6 +185,9 @@ MC_PICKLE_BEGIN_RECORD(MCScriptModule)
     MC_PICKLE_ARRAY_OF_RECORD(MCScriptPosition, positions, position_count)
 MC_PICKLE_END_RECORD()
 
+/* Re-enable invalid-offsetof warnings */
+#pragma GCC diagnostic pop
+
 ////////////////////////////////////////////////////////////////////////////////
 
 static MCScriptModule *s_modules = nil;
