Tidy: allow common lang+lib features
This allows changes to the Rust language that have both library
and language components share one feature gate.
The feature gates need to be "about the same change", so that both
library and language components must either be both unstable, or
both stable, and share the tracking issue.
Removes the ugly "proc_macro" exception added by #40939.
Closes#43089
Tells emcc to enable assertions and debugging information for
wasm32-experimental-emscripten. This makes the codegen issues caused by
LLVM bug 33824 manifest more frequently at runtime and improves the wasm
debugging experience.
Attempt to fix appveyor
This will fix the problem, I think, but I don't know that this is a good idea (potentially leaving ourselves open to attackers, I guess, if a cert was revoked...). Of course, it may not. I don't actually have windows to check on..
r? @alexcrichton
Add support for full RELRO
This commit adds support for full RELRO, and enables it for the
platforms I know have support for it.
Full RELRO makes the PLT+GOT data read-only on startup, preventing it
from being overwritten.
http://tk-blog.blogspot.com/2009/02/relro-not-so-well-known-memory.htmlFixesrust-lang/rust#29877.
---
I'm not entirely certain if this is the best way to do it, but I figured mimicking the way it's done for PIE seemed like a good start at least. I'm not sure whether we want to have it enabled by default globally and then disabling it explicitly for targets that don't support it though. I'm also not sure whether the `full_relro` function should call `bug!()` or something like it for linkers that don't support it rather than no-opping.
Slew of builtin-attribute gating tests
Slew of builtin-attribute "gating" tests for issue #43106.
Some stray observations:
* I don't know if its a good thing that so many attributes allow inputs which are silently discarded. (I made heavy use of that in writing my tests, but that was more out of curiosity than necessity.)
* The difference between crate-level and non-crate-level behavior is quite significant in some cases. Definitely worth making sure one has tests for both cases. (Not as clear whether it was worthwhile trying the various other AST forms like `fn f()` vs `struct S;`)
* `#[no_builtins]` and `#[no_mangle]` occur twice on the `BUILTIN_ATTRIBUTES` list. Thats almost certainly a bug. (Filed as #43148)
* We are maximally liberal in what we allow for `#[test]` and `#[bench]` when one compiles without `--test`.
* We allow `#[no_mangle]` on arbitrary AST nodes, but only warn about potential misuse on `fn`
* We allow `#[cold]`, `#[must_use]`, `#[windows_subsystem]`, and `#[no_builtins]` on arbitrary AST nodes. I don't know off-hand what the semantics are for e.g. a `#[cold] type T = ...;`
* We allow crate-level `#![inline]`. That's probably a bug since its otherwise restricted to `fn` items
Unify rules about commas in match arms and semicolons in expressions
Original discussion: https://internals.rust-lang.org/t/syntax-of-block-like-expressions-in-match-arms/5025/7.
Currently, rust uses different rules to determine if `,` is needed after an expression in a match arm and if `;` is needed in an expression statement:
```Rust
fn stmt() {
# no need for semicolons
{ () }
if true { () } else { () }
loop {}
while true {}
}
fn match_arm(n: i32) {
match n {
1 => { () } # can omit comma here
2 => if true { () } else { () }, # but all other cases do need commas.
3 => loop { },
4 => while true {},
_ => ()
}
}
```
This seems weird: why would you want to require `,` after and `if`?
This PR unifies the rules. It is backwards compatible because it allows strictly more programs.
float_bits_conv made it into 1.20
It seems that my PR to stabilize the `float_bits_conv` feature got merged before beta branched, which means I'm lucky, and the stabilization makes it into Rust 1.20. As it was against my expectations, the version number has to be corrected from 1.21 to 1.20.
Please also apply this PR to the beta branch.
Fix erroneous reference to Arc instead of Rc in rc::Weak documentation
The docs for `rc::Weak` refer to `Arc` in one place, where they should obviously be referring to `Rc`; presumably this was erroneously copied over from the `arc::Weak` docs.
`std::time::Duration`: improve _precision_ of terminology in docs
Changed wording of docs on `std::time::Duration` for better clarity w.r.t. the contents of the type and the purpose of its methods. (Specifically, removed the use of the word "precision" to describe the fractional part of the `Duration` because "precision" is more properly used to describe how _precise_ a value is, i.e. its granularity in this case.)
Workaround "Quasi-quoting is inefficient" warning in incremental rustbuild introduced in #43252.
After #43252 is merged, building stage0 libcore with `-i` (`--incremental`) flag will cause 17 "Quasi-quoting might make incremental compilation very inefficient: NtExpr(..)" warnings, as in #40946.
```
warning: Quasi-quoting might make incremental compilation very inefficient: NtExpr(..)
--> src/libcore/default.rs:133:21
|
133 | #[doc = $doc]
| ^^^^
...
139 | default_impl! { (), (), "Returns the default value of `()`" }
| ------------------------------------------------------------- in this macro invocation
(× 17)
```
True fix for #40946 will take at least 12 weeks from now to make into the next stage0, so it is quicker to workaround it in libcore instead.
cc @vbrandl @jseyfried
Change Travis CI job order.
Reorder the job matrix to take advantage of the order how Travis CI starts them in rust-lang/rust. Plus other refactoring of `.travis.yml`.
1. Move the `$ALLOW_PR` image to the top, so pull requests will start testing as immediately after the build is started. Previously the `$ALLOW_PR` image starts 6 minutes after the build was scheduled.
2. Move the slow macOS images near the top, so they share more time with the rest of the faster Linux builds, which should shorten total test time (actually not much, about 7 minutes at most if this change does work).
3. Merged the `install` section of both Linux and macOS to make the `env:` section a bit shorter, and enable change 4 below.
4. Do not download or install anything if `$SKIP_BUILD == true`, which further reduces chance of spurious failure in the PR-CI stage (avoid the red cross appearing even if CI passed).
(IMO `$SKIP_BUILD` should not even exist: those irrelevant jobs should not start at all, but that would require travis-ci/travis-ci#2778 which has been rejected)
Update docs on Error struct. #29355
This adds a pretty contrived example of the usage of fmt::Error. I am
very open to suggestions for a better one.
I have also highlighted the fmt::Error vs std::error::Error.
r? @steveklabnik
