Use --werror with Linux Clang builds

[kazarmy]

Your checklist for this pull request

• I've read the guidelines for contributing to this repository
• I made sure to follow the project's coding style
• I've documented or updated the documentation of every function and struct this PR changes. If not so I've explained why.
• I've added tests that prove my fix is effective or that my feature works (if possible)
• I've updated the rizin book with the relevant information (if needed)

Detailed description

Like the Linux gcc builds, the Linux Clang builds should also be done under --werror.

Test plan

All builds are green.

Closing issues

...

[ret2libc]

was this due to some specific clang warning for capstone? I think we already compiled with werror with gcc and capstone-bundled builds fine there.

[kazarmy]

Yes

(https://github.com/rizinorg/rizin/runs/4351274434?check_suite_focus=true#step:12:697)

Apparently that s_cpu_type variable is only used in a CS_ASSERT() call and therefore in a release build, the CS_ASSERT()s disappear and that variable is left hanging.

I would ofc prefer fixing that upstream but it can take time for such fixes to merge and any new Clang warnings that pop up in Rizin code should be caught immediately (such as the warning in #2042).

[kazarmy]

Apparently that s_cpu_type variable is only used in a CS_ASSERT() call and therefore in a release build, the CS_ASSERT()s disappear and that variable is left hanging.

Wait the above is not correct:

if (M680X_CPU_TYPE_ENDING != ARR_SIZE(s_cpu_type)) {
    CS_ASSERT(M680X_CPU_TYPE_ENDING == ARR_SIZE(s_cpu_type));

    return CS_ERR_MODE;
}

Now the warning looks like a false positive so perhaps I should just disable the warning for Clang.

[kazarmy]

Hmm now I think that Clang is justified in issuing that warning because the contents of s_cpu_type is not used.

[ret2libc]

It's alright. Thanks for explaining.
ANyway, it's not our code so it is not a huge deal if there are warnings there.

[XVilka]

@ret2libc @kazarmy I sent a PR long time ago in capstone and it was merged in "next": capstone-engine/capstone@c93fa3a

[kazarmy]

Ok capstone-engine/capstone#1801 is the cherry-pick pr for "v4".

[kabeor]

Hello guys, I have merged capstone-engine/capstone#1801. And btw, we are planning to pre-release capstone v5 base on next branch soon, so v4 will be deprecated. Welcome to PR or issues to next branch, I'll try my best to help.