exrcheck: update CMakeLists.txt to install the tool

[mattyjams]

While trying to diagnose a potential regression, I went looking for a validation command-line tool and came across exrcheck, but noticed that it does not currently get installed along with the other command-line tools (the CMake install() call is commented out). Spelunking through the ASWF Slack channel, it sounds like this was sort of intentional in that the tool is also oriented towards testing OpenEXR itself and not strictly a file validation tool. The question of whether exrcheck gets installed seems to have come up enough that it seems worth doing. See for example:
https://academysoftwarefdn.slack.com/archives/CMLRW4N73/p1707504987153709
https://academysoftwarefdn.slack.com/archives/CMLRW4N73/p1724241705200189

The change here is mostly just conforming exrcheck's CMakeLists.txt to look like other command-line tools, in particular exrinfo's.

As far as the regression, once I had exrcheck installed I was able to use it to find that a test file was deemed OK through the file API, but bad through the stream API (with the -s option), so I'll be digging into that further and possibly opening another issue or PR if I can find anything.

[cary-ilm]

@peterhillman, I know you originally developed exrcheck as an internal tool, but if it's generally useful for debugging/diagnostics, any reason not to officially distribute it?

[peterhillman]

Yes, we should update to allowexrcheck to be installed optionally. One question is whether it should have a separate install option apart from the other utilities. Although it is one way to verify that an OpenEXR is complete and fully readable, its main use is to allow developers to test the library itself for security issues when reading files. It is therefore very unwise to read untrusted files using it. If exrcheck had a separate install option so it wasn't installed by default it could avoid some misunderstandings?

[mattyjams]

Thanks for the info, @cary-ilm and @peterhillman!

I see what you mean about exrcheck not really being an end-user tool. I definitely found it immensely helpful though in tracking down the issue in #1984 since I actually was looking for a possible bug in OpenEXR itself, so thanks very much for that @peterhillman!

I don't know whether there are any other tools that fall into this category, but along the lines of @peterhillman's suggestion, would a new option like OPENEXR_INSTALL_DEVELOPER_TOOLS make sense? I'm happy to add some commits for that to this PR if that sounds like the right way to optionally expose exrcheck. Let me know what you think!

EDIT: removed the suggestion of an additional ...BUILD... option, since on second thought I think this tool is used by tests and other parts of the infrastructure and needs to always build.

[peterhillman]

Yes, although it's verging on overkill to introduce a new option I think it does make sense in this case. I think the CI would also have to be updated to set that option so we can verify it gets installed.

I would expect package managers would want to make the developer tools a separate package to regular tools so it is not normally installed, but still discoverable via a package search or a shell's command_not_found_handle. This change would simplify setting up that package.

[mattyjams]

Thanks @peterhillman!

I took a crack at adding an OPENEXR_INSTALL_DEVELOPER_TOOLS option. It defaults to OFF, and exrcheck is currently the only tool in this "developer" category.

I also made an attempt at documenting the new option in website/install.rst and website/tools.rst, but feel free to suggest any wordsmith-y changes to that. :)

I did not turn the new option on for any CI tasks yet (I think those are configured separately, outside of the repo?), so there aren't currently any install manifests that include exrcheck. Let me know what the preferred way to set that up would be.

[peterhillman]

This looks good to me, though I'm not a cmake expert

[peterhillman]

is it worth mentioning that exrcheck is compiled even if the option is OFF, and can be run directly from the build/bin folder without installing it?

[mattyjams]

Good idea! I tried to incorporate that into the verbiage with commit 1adf14d.

Thanks @peterhillman!

[cary-ilm]

Thanks!