clarify partially initialized Mutex issues
Using a `sys_common::mutex::Mutex` without calling `init` is dangerous, and yet there are some places that do this. I tried to find all of them and add an appropriate comment about reentrancy.
I found two places where (I think) reentrancy can actually occur, and was not able to come up with an argument for why this is okay. Someone who knows `io::lazy` and/or `sys_common::at_exit_imp` should have a careful look at this.
[NLL] Use span of the closure args in free region errors
Also adds a note when one of the free regions is BrEnv.
In a future PR I'll change these messages to say "return requires", which should improve them a bit more.
r? @nikomatsakis
Make IpvXAddr::new const fns and the well known addresses associated constants
Implements/fixes https://github.com/rust-lang/rust/issues/44582
I just got a PR towards libc (https://github.com/rust-lang/libc/pull/1044) merged. With the new feature added in that PR it is now possible to create `in6_addr` instances as consts. This enables us to finally make the constructors of the IP structs const fns and to make the localhost/unspecified addresses associated constants, as agreed in the above mentioned tracking issue.
I also added a BROADCAST constant. Personally this is the well known address I tend to need the most often.
resolve: Support custom attributes when macro modularization is enabled
Basically, if resolution of a single-segment attribute is a determined error, then we interpret it as a custom attribute.
Since custom attributes are integrated into general macro resolution, `feature(custom_attribute)` now requires and implicitly enables macro modularization (`feature(use_extern_macros)`).
Actually, a few other "advanced" macro features now implicitly enable macro modularization too (and one bug was found and fixed in process of enabling it).
The first two commits are preliminary cleanups/refactorings.
When missing a comma in a macro call, suggest it, regardless of
position. When a macro call doesn't match any of the patterns, check
if the call's token stream could be missing a comma between two idents,
and if so, create a new token stream containing the comma and try to
match against the macro patterns. If successful, emit the suggestion.
