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A major issue with removing UB exploitation is that you've now created C, but each compiler implements a different C. It becomes harder to port code, and you e

A major issue with removing UB exploitation is that you've now created C, but each compiler implements a different C. It becomes harder to port code, and you end up with bugs that can be harder to catch, especially if don't consider what you're doing an error, as now you can't even use the sanitizers. What my team has been looking at to help developers that have these issues is providing low overhead ways to give defined, but likely to crash, behavior for these cases. This helps protects against UB without creating C. An example would be variable auto-init, which intentionally doesn't support zero init, as that is likely to hide bugs: https://reviews.llvm.org/D54604 https://reviews.llvm.org/D54604 I'm fine with fully defining some things that are currently UB or IB. I'm also fine with keeping things as UB. What I'm not fine with is creating this implicit C that programmers think they know what it is, but it's not actually defined anywhere, and not everyone working on the compiler is on the same page about.

perl4ever 7y ago
To me, whenever something is undefined at one level, there are still constraints on it at another level. We go about our daily lives without laws and regulations explicitly detailing our every interaction, and rely on custom and ingrained behavioral rules to fill in the gaps. Every level of abstraction has another layer behind it. When I read someone arguing about undefined behavior allowing a compiler writer to do anything, it makes me imagine someone who, if they could afford the finest lawyers and found the appropriate loophole, would consider it not just their right, but their duty, to kill and eat me. It's not terrifying to imagine there are monsters here and there; there always have been a certain number. What terrifies me is the idea that this mentality is infecting society and altering norms and interactions. It doesn't feel like evil as such, it feels more like a metaphorical prion disease. There's something fundamental to being a human being in being able to deal with undefined situations by breaking out of a given context into a broader one.

perl4ever 7y ago

To me, whenever something is undefined at one level, there are still constraints on it at another level. We go about our daily lives without laws and regulations explicitly detailing our every interaction, and rely on custom and ingrained behavioral rules to fill in the gaps. Every level of abstraction has another layer behind it. When I read someone arguing about undefined behavior allowing a compiler writer to do anything, it makes me imagine someone who, if they could afford the finest lawyers and found the appropriate loophole, would consider it not just their right, but their duty, to kill and eat me. It's not terrifying to imagine there are monsters here and there; there always have been a certain number. What terrifies me is the idea that this mentality is infecting society and altering norms and interactions. It doesn't feel like evil as such, it feels more like a metaphorical prion disease. There's something fundamental to being a human being in being able to deal with undefined situations by breaking out of a given context into a broader one.