Compile failure with optimized ASan builds about hermes

[tmikov]

Just tried and couldn't reproduce on MacOS. Will try Linux next.

[tmikov]

Does not reproduce on Linux with CLang. Must be GCC specific.

[tmikov]

Hi, @nth10sd. I was able to reproduce this on Linux with gcc. The fix is in #1227 .

I understand that this mode (opt ASan) is not in the README - my question is, will this mode ever be supported?

It depends on what you mean by "supported". We are not proactively testing the configuration "gcc+opt+ASAN+Linux" and have no plans to change that for now, since we don't use it ourselves. So, we can't guarantee that we will always investigate and address reports like this one promptly (in this case, I got just curious and dug a little, but I don't always have the time). Mostly, we expect improvements and bugfixes for such cases from the community, in the form of PRs.

OTOH, "clang+opt+ASAN+MacOS" is much higher on our list of priorities.

Generally speaking, as an open source project, we can't provide real support for building the project. It is all best effort. We do our best to make it buildable and runnable on as wide possible set of platforms and compilers, but ultimately it has to be assumed that developers trying to build Hermes (as opposed to just use it) can deal with the associated challenges. That goes double for running in ASAN mode. Hopefully devs who want to run Hermes with ASAN can help us with diagnosing and fixing the associated problems.

So, for example, if someone wanted to build and run Hermes on OpenBSD, we couldn't help with that, or "support" that case. But if they submitted a well documented PR, we would gladly accept it.

[nth10sd]

It depends on what you mean by "supported". We are not proactively testing the configuration "gcc+opt+ASAN+Linux" and have no plans to change that for now, since we don't use it ourselves. So, we can't guarantee that we will always investigate and address reports like this one promptly (in this case, I got just curious and dug a little, but I don't always have the time).

Understood, thanks for fixing this one!