Enable recursion for visit_ty in lint visitor

[ipetkov]

• The lint visitor's visit_ty method did not recurse, and had a
  reference to the now closed Enabling recursion in Visitor.visit_ty makes the compiler reject fixed-length arrays #10894
• The newly enabled recursion has only affected the deprectated lint
  which now detects uses of deprecated items in trait impls and
  function return types
• Renamed some references to CowString and CowVec to Cow<str> and
  Cow<[T]>, respectively, which appear outside of the crate which
  defines them
• Replaced a few instances of InvariantType<T> with
  PhantomData<Cell<T>>
• Disabled the deprecated lint in several places that
  reference/implement traits on deprecated items which will get cleaned
  up in the future
• Unfortunately, this means that if a library declares
  #![deny(deprecated)] and marks anything as deprecated, it will have
  to disable the lint for any uses of said item, e.g. any impl the now
  deprecated item

For any library that denies deprecated items but has deprecated items
of its own, this is a [breaking-change]

I had originally intended for the lint to ignore uses of deprecated items that are declared in the same crate, but this goes against some previous test cases that expect the lint to capture all uses of deprecated items, so I maintained the previous approach to avoid changing the expected behavior of the lint.

Tested locally on OS X, so hopefully there aren't any deprecated item uses behind a cfg that I may have missed.

[rust-highfive]

r? @pcwalton

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[alexcrichton]

@bors: r+ 3ad59a0

Thanks!

[bors]

⌛ Testing commit 3ad59a0 with merge 0a2bc7f...

[bors]

⌛ Testing commit 3ad59a0 with merge f78333e...

[Manishearth]

@bors: r-

[Manishearth]

make check-stage1-std fails for me locally

time, please rewrite code that relies on it
/opt/rust/src/libstd/lib.rs:116 #![feature(old_impl_check)]
                                           ^~~~~~~~~~~~~~
/opt/rust/src/libstd/thread_local/scoped.rs:122:51: 122:70 error: chained comparison operators require parentheses
/opt/rust/src/libstd/thread_local/scoped.rs:122                 marker: ::std::marker::PhantomData<::std::cell::Cell<$t>>,
                                                                                                  ^~~~~~~~~~~~~~~~~~~
/opt/rust/src/libstd/thread_local/scoped.rs:122:70: 122:72 error: unexpected token: `u32`
/opt/rust/src/libstd/thread_local/scoped.rs:122                 marker: ::std::marker::PhantomData<::std::cell::Cell<$t>>,

Looks like that macro is only used internally in the tests, and the parsing is off for those. I guess adding some parens might help?

[bors]

💔 Test failed - auto-linux-64-nopt-t

[Manishearth]

Probably needs d3cc32f (not tested yet)

[Manishearth]

I got this failure as part of the rollup

------------------------------------------
stderr:
------------------------------------------
/Users/rustbuild/src/rust-buildbot/slave/auto-mac-32-opt/build/src/test/compile-fail/huge-array-simple.rs:14:8: 14:11 warning: unused variable: `fat`, #[warn(unused_variables)] on by default
/Users/rustbuild/src/rust-buildbot/slave/auto-mac-32-opt/build/src/test/compile-fail/huge-array-simple.rs:14    let fat : [u8; (1<<61)+(1<<31)] = [0; (1u64<<61) as usize +(1u64<<31) as usize];
                                                                                                                    ^~~
/Users/rustbuild/src/rust-buildbot/slave/auto-mac-32-opt/build/src/test/compile-fail/huge-array-simple.rs:14:20: 14:25 error: bitshift exceeds the type's number of bits, #[deny(exceeding_bitshifts)] on by default
/Users/rustbuild/src/rust-buildbot/slave/auto-mac-32-opt/build/src/test/compile-fail/huge-array-simple.rs:14    let fat : [u8; (1<<61)+(1<<31)] = [0; (1u64<<61) as usize +(1u64<<31) as usize];
                                                                                                                                ^~~~~
error: aborting due to previous error

------------------------------------------

[nagisa]

Relevant IRC logs

[ipetkov]

@Manishearth didn't get the error on my 64bit machine, so it's definitely a machine dependent error since it the exceeding_bitshifts lint is now correctly triggering on 32bit machines. I think it would be appropriate to disable it for this particular test so it doesn't shadow the expected too big for the current architecture error.

[ipetkov]

@alexcrichton updated the PR branch with a fix for that failing test case and incorporated @Manishearth syntax fix

[alexcrichton]

@bors: r+ 2b03718

Thanks!