Fix most warnings in tests

[cristicbz]

This PR attempts to fix most warnings spewed by running make check:

• Adds several #[allow(deprecated)] attributes to tests which test deprecated code: unfoldr, BufStream, RandomAccessIterator, reverse_in_place, thread::scoped.
• Adds underscores to a bunch of unused args and locals.
• Adds #[cfg(not(test))] to places like primitive inherent impls where, AFAIU, where at test time the impls themselves are not requried since they are already provied by the libstd crate against which we link.
• Removes several unused imports from a bunch of places.
• Replaces Thunk to FnBox in remutex.rs and gets rid of thread::scoped.

After these changes, I still get some warnings, which I find really strange:

• In sync::future the tests throw deprecation warnings despite the toplevel module attribute allowing deprecation. Weird.
• I get a warning with the text for the Future deprecation, but target at libstd/lib.rs line 1 column 1:

src/libstd/lib.rs:1:1: 1:1 warning: use of deprecated item: implementation does not match the quality of the standard library and this will likely be prototyped outside in crates.io first, #[warn(deprecated)] on by default
src/libstd/lib.rs:1 // Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT

• Unknown feature for definitely known feature. Is this some kind of weird artifact of how staging works? Would some kind of #[cfg(not(test))] for the feature be helpful?

src/libstd/lib.rs:118:12: 118:22 warning: unused or unknown feature, #[warn(unused_features)] on by default
src/libstd/lib.rs:118 #![feature(core_float)]
                                 ^~~~~~~~~~

• Unused warnings for things which are definitely used:

src/libstd/sys/unix/stack_overflow.rs:64:5: 64:37 warning: static item is never used: `PAGE_SIZE`, #[warn(dead_code)] on by default
src/libstd/sys/unix/stack_overflow.rs:64     static mut PAGE_SIZE: usize = 0;
                                             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
src/libstd/sys/unix/stack_overflow.rs:67:5: 95:6 warning: function is never used: `signal_handler`, #[warn(dead_code)] on by default
src/libstd/sys/unix/stack_overflow.rs:67     unsafe extern fn signal_handler(signum: libc::c_int,
src/libstd/sys/unix/stack_overflow.rs:68                                      info: *mut siginfo,
src/libstd/sys/unix/stack_overflow.rs:69                                      _data: *mut libc::c_void) {
src/libstd/sys/unix/stack_overflow.rs:70
src/libstd/sys/unix/stack_overflow.rs:71         // We can not return from a SIGSEGV or SIGBUS signal.
src/libstd/sys/unix/stack_overflow.rs:72         // See: https://www.gnu.org/software/libc/manual/html_node/Handler-Returns.html
                                         ...
src/libstd/sys/unix/stack_overflow.rs:74:9: 80:10 warning: function is never used: `term`, #[warn(dead_code)] on by default
src/libstd/sys/unix/stack_overflow.rs:74         unsafe fn term(signum: libc::c_int) -> ! {
src/libstd/sys/unix/stack_overflow.rs:75             use core::mem::transmute;
src/libstd/sys/unix/stack_overflow.rs:76
src/libstd/sys/unix/stack_overflow.rs:77             signal(signum, transmute(SIG_DFL));
src/libstd/sys/unix/stack_overflow.rs:78             raise(signum);
src/libstd/sys/unix/stack_overflow.rs:79             intrinsics::abort();
                                         ...
src/libstd/sys/unix/stack_overflow.rs:99:5: 116:6 warning: function is never used: `init`, #[warn(dead_code)] on by default
src/libstd/sys/unix/stack_overflow.rs:99     pub unsafe fn init() {
src/libstd/sys/unix/stack_overflow.rs:100         let psize = libc::sysconf(libc::consts::os::sysconf::_SC_PAGESIZE);
src/libstd/sys/unix/stack_overflow.rs:101         if psize == -1 {
src/libstd/sys/unix/stack_overflow.rs:102             panic!("failed to get page size");
src/libstd/sys/unix/stack_overflow.rs:103         }
src/libstd/sys/unix/stack_overflow.rs:104

[rust-highfive]

Thanks for the pull request, and welcome! The Rust team is excited to review your changes, and you should hear from @huonw (or someone else) soon.

If any changes to this PR are deemed necessary, please add them as extra commits. This ensures that the reviewer can see what has changed since they last reviewed the code. The way Github handles out-of-date commits, this should also make it reasonably obvious what issues have or haven't been addressed. Large or tricky changes may require several passes of review and changes.

Please see the contribution instructions for more information.

[alexcrichton]

@bors: r+ 2106e003f7adf403178be9eb41be2b8e7ad57961

Certainly a great step forward, thanks!

Would some kind of #[cfg(not(test))] for the feature be helpful?

You should be able to add #[cfg_attr(not(test), feature(...))]

[bors]

⌛ Testing commit 2106e00 with merge e5a9d69...

[bors]

💔 Test failed - auto-mac-64-opt

[cristicbz]

Silly leftover issue in the iter.rs integration test. Though I swear I did run a full make check before---doesn't make check do all stages?

@bors: retry 257212a

[cristicbz]

@bors: try

[alexcrichton]

@bors: r+ 257212a

Perhaps it's a platform-specific issue?

[bors]

⌛ Testing commit 257212a with merge a497482...

[bors]

💔 Test failed - auto-win-gnu-64-opt

[alexcrichton]

@bors: retry

[bors]

⌛ Testing commit 257212a with merge 150358a...

[bors]

💔 Test failed - auto-linux-64-x-android-t

[bors]

☔ The latest upstream changes (presumably #26631) made this pull request unmergeable. Please resolve the merge conflicts.

[huonw]

Hey @cristicbz, this seems to need a rebase. 😄

[cristicbz]

Ah yes, sorry this fell through the cracks. I'm struggling a bit to repro the failed tests though. Is running make check enough? It seems like the buildbots trigger things I don't.

[huonw]

Don't worry! It feel through my cracks too.

The build-bots do make check, but they run on more platforms (windows, mac, linux, ...) and configurations.

[Gankra]

@cristicbz feel free to push up changes you think work and we can run them on our try servers for you.

[steveklabnik]

@cristicbz it's been a long time, are you still interested in fixing up this PR, or should we close it?

[cristicbz]

Sorry about this, I'll close it. I might have a new, more focused go when I get more time, I've just been utterly swamped for the last few months or so :(

[steveklabnik]

Completely understood, happens to us all. Good luck with things!