paulf38

I think that the point being made was that you cannot edit code with gdb and Valgrind, not that you can’t edit the code of gdb and Valgrind.

I look regularly, but all I see is tumbleweeds. Questions about Valgrind (my main interest) have shriveled from a few every week to about 1 every 3 months.

Sometimes I troll meta where the mods and “curators” (as they call themselves) hang out. The staff mods have finally twigged that indiscriminate close voting is a bad thing. A typical example of that would be an ego tripping “curator” that works on Windows with HTML and CSS voting to close a question about Linux OpenZFS library interfaces because the question is “not about programming”. I somehow fail to see how CSS experience qualifies a person to judge questions about ZFS.

It could have been either Valgrind or OpenSSL.

I call this UB exceptionalism. Your UB is bad and you need to fix it. My UB is a valid optimisation and the tools are producing false positives.

Valgrind only detects UB. We can do something for standard libraries that exploit this kind of UB - Valgrind replaces functions like strlcpy with its own versions that do not contain any UB. We can’t do that for all user libraries.

Who are ‘they’? OpenSSL?

"valgrind and msan will give you an immediate and false positive message"

Why a false positive? Are you one of those people that 'knows' that their code is correct and always blames the tool? What you describe sounds like a real error. Sort of. The error is not triggered by reading the value, it gets triggered when it is used in some conditional context and the undefinedness has an observable impact on the execution of the program.

This is a change from undefined/erroneous behaviour to something else - defined but maybe not what you wanted.

I agree that this can make error analysis more difficult.

Is that something that should be merged to upstream Valgrind?

And sadly that was one that I broke trying to refactor together all our C++ autoconf tests. Silver lining, I added a test for it so if I break it again we should notice earlier.