> If I fix the punning warnings, the problem goes away. Interesting! I spent some time in my last job (before retiring) analyzing and trying to fix type-punned-pointer warnings in a very large old package. My take-away was that some well-intentioned people purposely broke old C code in the name of efficiency (smarter and smarter compilers) by allowing higher levels of optimization to make sometimes bad assumptions about apparently non-overlapping memory addresses that in fact do overlap. The decision might go back to 1999!
The best they could seem to offer was obscure warnings (unless you hid them) leading to some real head-scratching about what exactly was the problem and how to fix it. Despite deep analysis (now mostly forgotten) we never did 100% understand precisely how to "do the right thing" in all cases... For example, unions were supposed to be a way to tell the compiler, "I really mean to overlap these bytes" but it didn't always make the warnings go away. Conversely it seemed like doing a cast should be ironclad evidence of intention, yet it was deemed insufficient. We converted a lot of old code to use unions hoping they would work properly and at no significant added CPU cost. Funny thing is, we NEVER saw a single code misbehavior directly linked to type-punned pointers. Cheers, Alan Silverstein ------------------------------------------------------------------------------ Is your legacy SCM system holding you back? Join Perforce May 7 to find out: • 3 signs your SCM is hindering your productivity • Requirements for releasing software faster • Expert tips and advice for migrating your SCM now http://p.sf.net/sfu/perforce _______________________________________________ Judy-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/judy-devel
