Rollup merge of #54299 - snaedis:issue-54246, r=varkor
Issue 54246
I added the option of providing a help message for deprecated features, that takes precedence over the default `help: remove this attribute` message, along with messages for the features that mention replacements in the reason for deprecation.
Rollup merge of #54232 - pnkfelix:add-way-to-disable-diagnostic-buffering, r=nikomatsakis
add `-Z dont-buffer-diagnostics`
Add `-Z dont-buffer-diagnostics`, a way to force NLL to immediately its diagnostics.
This is mainly intended for developers who want to see the error in its original context in the control flow. Two uses cases for that are:
1. `-Z treat-err-as-bug` (which then allows extraction of a stack-trace to the origin of the error)
2. RUST_LOG=... rustc, in which case it is often useful to see the logging statements that occurred immediately prior to the point where the diagnostic was signalled.
Rollup merge of #54225 - pnkfelix:issue-53675-add-test-called-panic, r=petrochenkov
Regression test for rust-lang/rust#53675.
(Includes a couple variations on the theme. I confirmed that the ones
in `in_expression_position` and `what_if_we_use_panic_directly_in_expr`
both failed back on "rustc 1.30.0-nightly (0f063aef6 2018-09-03)".)
Auto merge of #54286 - nnethercote:BitSet, r=pnkfelix
Merge `bitvec.rs` and `indexed_set.rs`
Because it's not good to have two separate implementations. Also, I will combine the best parts of each to improve NLL memory usage on some benchmarks significantly.
`BitwiseOperator` is an unnecessarily low-level thing. This commit
replaces it with `BitSetOperator`, which works on `BitSet`s instead of
words. Within `bit_set.rs`, the commit eliminates `Intersect`, `Union`,
and `Subtract` by instead passing a function to `bitwise()`.
Merge indexed_set.rs into bitvec.rs, and rename it bit_set.rs.
Currently we have two files implementing bitsets (and 2D bit matrices).
This commit combines them into one, taking the best features from each.
This involves renaming a lot of things. The high level changes are as
follows.
- bitvec.rs --> bit_set.rs
- indexed_set.rs --> (removed)
- BitArray + IdxSet --> BitSet (merged, see below)
- BitVector --> GrowableBitSet
- {,Sparse,Hybrid}IdxSet --> {,Sparse,Hybrid}BitSet
- BitMatrix --> BitMatrix
- SparseBitMatrix --> SparseBitMatrix
The changes within the bitset types themselves are as follows.
```
OLD OLD NEW
BitArray<C> IdxSet<T> BitSet<T>
-------- ------ ------
grow - grow
new - (remove)
new_empty new_empty new_empty
new_filled new_filled new_filled
- to_hybrid to_hybrid
clear clear clear
set_up_to set_up_to set_up_to
clear_above - clear_above
count - count
contains(T) contains(&T) contains(T)
contains_all - superset
is_empty - is_empty
insert(T) add(&T) insert(T)
insert_all - insert_all()
remove(T) remove(&T) remove(T)
words words words
words_mut words_mut words_mut
- overwrite overwrite
merge union union
- subtract subtract
- intersect intersect
iter iter iter
```
In general, when choosing names I went with:
- names that are more obvious (e.g. `BitSet` over `IdxSet`).
- names that are more like the Rust libraries (e.g. `T` over `C`,
`insert` over `add`);
- names that are more set-like (e.g. `union` over `merge`, `superset`
over `contains_all`, `domain_size` over `num_bits`).
Also, using `T` for index arguments seems more sensible than `&T` --
even though the latter is standard in Rust collection types -- because
indices are always copyable. It also results in fewer `&` and `*`
sigils in practice.
Auto merge of #54277 - petrochenkov:afterder, r=alexcrichton
Temporarily prohibit proc macro attributes placed after derives
... and also proc macro attributes used together with `#[test]`/`#[bench]`.
Addresses item 6 from https://github.com/rust-lang/rust/pull/50911#issuecomment-411605393.
The end goal is straightforward predictable left-to-right expansion order for attributes.
Right now derives are expanded last regardless of their relative ordering with macro attributes and right now it's simpler to temporarily prohibit macro attributes placed after derives than changing the expansion order.
I'm not sure whether the new beta is already released or not, but if it's released, then this patch needs to be backported, so the solution needs to be minimal.
How to fix broken code (derives):
- Move macro attributes above derives. This won't change expansion order, they are expanded before derives anyway.
Using attribute macros on same items with `#[test]` and `#[bench]` is prohibited for similar expansion order reasons, but this one is going to be reverted much sooner than restrictions on derives.
How to fix broken code (test/bench):
- Enable `#![feature(plugin)]` (don't ask why).
Add -Z dont-buffer-diagnostics, a way to force NLL to immediately emit its diagnostics.
This is mainly intended for `rustc` developers who want to see a
diagnostic in its original context in the control flow. Two uses
cases for that are:
* `-Z treat-err-as-bug` which then allows extraction of a stack-trace to the origin of the error
(a case that is so important that we make that flag imply this one, effectively).
* `RUST_LOG=... rustc`, in which case it is often useful to see the logging statements that
occurred immediately prior to the point where the diagnostic was signalled.
Drive-by: Added some documentation pointing future devs at
HandlerFlags, and documented the fields of `HandlerFlags` itself.
Auto merge of #54260 - maxdeviant:public-scope-fields, r=petrochenkov
Make rustc::middle::region::Scope's fields public
This PR makes the following changes to `rustc::middle::region::Scope`:
- [x] Makes `region::Scope`'s fields public
- [x] Removes the `impl Scope` block with constructors (as per [this comment](https://github.com/rust-lang/rust/pull/54032#discussion_r216618208))
- [x] Updates call sites throughout the compiler
Auto merge of #54254 - RalfJung:miri-dangling, r=eddyb
miri engine: keep around some information for dead allocations
We use it to test if a dangling ptr is aligned and non-NULL. This makes some code pass that should pass (writing a ZST to a properly aligned dangling pointer), and makes some code fail that should fail (writing a ZST to a pointer obtained via pointer arithmetic from a real location, but ouf-of-bounds -- that pointer could be NULL, so we cannot allow writing to it).
CTFE does not allow these operations; tests are added to miri with https://github.com/solson/miri/pull/453.
Auto merge of #54247 - Munksgaard:better-error-message-in-no_lookup_host_duplicates, r=alexcrichton
Improve output if no_lookup_host_duplicates test fails
If the test fails, output the offending addresses and a helpful error message.
Also slightly improve legibility of the preceding line that puts the addresses
into a HashMap.
Auto merge of #53461 - petrochenkov:pmu, r=alexcrichton
resolve: Do not error on access to proc macros imported with `#[macro_use]`
This error is artificial, but previously, when `#[macro_use] extern crate x;` was stable, but non-derive proc macros were not, it worked like kind of a feature gate. Now both features are stable, so the error is no longer necessary.
This PR simplifies how `#[macro_use] extern crate x;` works - it takes all items from macro namespace of `x`'s root and puts them into macro prelude from which they all can now be accessed.
Auto merge of #53804 - RalfJung:ptr-invalid, r=nagisa
fix some uses of pointer intrinsics with invalid pointers
[Found by miri](https://github.com/solson/miri/pull/446):
* `Vec::into_iter` calls `ptr::read` (and the underlying `copy_nonoverlapping`) with an unaligned pointer to a ZST. [According to LLVM devs](https://bugs.llvm.org/show_bug.cgi?id=38583), this is UB because it contradicts the metadata we are attaching to that pointer.
* `HashMap` creation calls `ptr:.write_bytes` on a NULL pointer with a count of 0. This is likely not currently UB *currently*, but it violates the rules we are setting in https://github.com/rust-lang/rust/pull/53783, and we might want to exploit those rules later (e.g. with more `nonnull` attributes for LLVM).
Probably what `HashMap` really should do is use `NonNull::dangling()` instead of 0 for the empty case, but that would require a more careful analysis of the code.
It seems like ideally, we should do a review of usage of such intrinsics all over libstd to ensure that they use valid pointers even when the size is 0. Is it worth opening an issue for that?
Auto merge of #54157 - euclio:structured-suggestion, r=estebank
use structured suggestion for "missing mut" label
Fixes #54133 for both NLL and non-NLL.
r? @estebank
I'm not super happy with the existing wording here, since it's now a suggestion. I wonder if the message would work better as something like "help: make binding mutable: `mut foo`"?
Also, are the `HELP` and `SUGGESTION` comments necessary?
Auto merge of #53754 - RalfJung:slice_align_to, r=alexcrichton
stabilize slice_align_to
This is very hard to implement correctly, and leads to [serious bugs](https://github.com/llogiq/bytecount/pull/42) when done incorrectly. Moreover, this is needed to be able to run code that opportunistically exploits alignment on miri. So code using `align_to`/`align_to_mut` gets the benefit of a well-tested implementation *and* of being able to run in miri to test for (some kinds of) UB.
This PR also clarifies the guarantee wrt. the middle part being as long as possible. Should the docs say under which circumstances the middle part could be shorter? Currently, that can only happen when running in miri.
Auto merge of #54116 - eddyb:extern-prelude, r=petrochenkov
rustc_resolve: allow only core, std, meta and --extern in Rust 2018 paths.
As per https://github.com/rust-lang/rust/issues/53166#issuecomment-419265401:
* Rust 2018 imports can no longer refer to crates not in "extern prelude"
* `::foo` won't load a crate named `foo` unless `foo` is in the "extern prelude"
* `extern crate foo;`, however, remains unchanged (can load arbitrary crates)
* `--extern crate_name` is added (note the lack of `=path`) as an unstable option
* adds `crate_name` to the "extern prelude" (see above)
* crate is searched in sysroot & library paths, just like `extern crate crate_name`.
* `Cargo` support will be added later
* `core`, `std` and ~~`proc_macro`~~ `meta` are *always* available in the extern prelude
* warning for interaction with `no_std` / `no_core` will be added later
* **EDIT**: `proc_macro` was replaced by `meta`, see https://github.com/rust-lang/rust/issues/53166#issuecomment-421137230
* note that there is no crate named `meta` being added, so `use meta::...;` will fail, we're only whitelisting it so we can start producing `uniform_paths` compatibility errors
Fixes #54006 (as the example now requires `--extern alloc`, which is unstable).
Fixes #54253 (hit during fixing RLS).
r? @petrochenkov cc @aturon @alexcrichton @Centril @joshtriplett
If the test fails, output the offending addresses and a helpful error message.
Also slightly improve legibility of the preceding line that puts the addresses
into a HashMap.
(Includes a couple variations on the theme. I confirmed that the ones
in `in_expression_position` and `what_if_we_use_panic_directly_in_expr`
both failed back on "rustc 1.30.0-nightly (0f063aef6 2018-09-03)".)
Auto merge of #54151 - ljedrz:cleanup_hir, r=michaelwoerister
A few cleanups for hir
- prefer `if let` to `match` when only 1 branch matters
- `chain` iterable items that are looped over in sequence
- `sort_by_key` instead of `sort_by` when possible
- change cloning `map`s to `cloned()`
- use `unwrap_or_else` and `ok` when applicable
- a few other minor readability improvements
- whitespace fixes
Auto merge of #54069 - petrochenkov:subns, r=aturon
resolve: Introduce two sub-namespaces in macro namespace
Two sub-namespaces are introduced in the macro namespace - one for bang macros and one for attribute-like macros (attributes, derives).
"Sub-namespace" means this is not a newly introduced full namespace, the single macro namespace is still in place.
I.e. you still can't define/import two macros with the same name in a single module, `use` imports still import only one name in macro namespace (from any sub-namespace) and not possibly two.
However, when we are searching for a name used in a `!` macro call context (`my_macro!()`) we skip attribute names in scope, and when we are searching for a name used in attribute context (`#[my_macro]`/`#[derive(my_macro)]`) we are skipping bang macro names in scope.
In other words, bang macros cannot shadow attribute macros and vice versa.
For a non-macro analogy, we could e.g. skip non-traits when searching for `MyTrait` in `impl MyTrait for Type { ... }`.
However we do not do it in non-macro namespaces because we don't have practical issues with e.g. non-traits shadowing traits with the same name, but with macros we do, especially after macro modularization.
For `#[test]` and `#[bench]` we have a hack in the compiler right now preventing their shadowing by `macro_rules! test` and similar things. This hack was introduced after making `#[test]`/`#[bench]` built-in macros instead of built-in attributes (https://github.com/rust-lang/rust/pull/53410), something that needed to be done from the start since they are "active" attributes transforming their inputs.
Now they are passed through normal name resolution and can be shadowed, but that's a breaking change, so we have a special hack basically applying this PR for `#[test]` and `#[bench]` only.
Soon all potentially built-in attributes will be passed through normal name resolution (https://github.com/rust-lang/rust/pull/53913) and that uncovers even more cases where the strict "macro namespace is a single namespace" rule needs to be broken.
For example, with strict rules, built-in macro `cfg!(...)` would shadow built-in attribute `#[cfg]` (they are different things), standard library macro `thread_local!(...)` would shadow built-in attribute `#[thread_local]` - both of these cases are covered by special hacks in https://github.com/rust-lang/rust/pull/53913 as well.
Crater run uncovered more cases of attributes being shadowed by user-defined macros (`warn`, `doc`, `main`, even `deprecated`), we cannot add exceptions in the compiler for all of them.
Regressions with user-defined attributes like https://github.com/rust-lang/rust/issues/53583 and https://github.com/rust-lang/rust/issues/53898 also appeared after enabling macro modularization.
People are also usually confused (https://github.com/rust-lang/rust/issues/53205#issuecomment-411552763, https://github.com/rust-lang/rust/issues/53583#issuecomment-415447800) when they see conflicts between attributes and non-attribute macros for the first time.
So my proposed solution is to solve this issue by introducing two sub-namespaces and thus skipping resolutions of the wrong kind and preventing more error-causing cases of shadowing.
Auto merge of #54201 - eddyb:reflexive-disambiguation, r=petrochenkov
rustc_resolve: don't treat uniform_paths canaries as ambiguities unless they resolve to distinct Def's.
In particular, this allows this pattern that @cramertj mentioned in https://github.com/rust-lang/rust/issues/53130#issuecomment-420848814:
```rust
use log::{debug, log};
fn main() {
use log::{debug, log};
debug!(...);
}
```
The canaries for the inner `use log::...;`, *in the macro namespace*, see the `log` macro imported at the module scope, and the (same) `log` macro, imported in the block scope inside `main`.
Previously, these two possible (macro namspace) `log` resolutions would be considered ambiguous (from a forwards-compat standpoint, where we might make imports aware of block scopes).
With this PR, such a case is allowed *if and only if* all the possible resolutions refer to the same definition (more specifically, because the *same* `log` macro is being imported twice).
This condition subsumes previous (weaker) checks like #54005 and the second commit of #54011.
Only the last commit is the main change, the other two are cleanups.
Auto merge of #54088 - matthewjasper:use-reason-in-dlle-errors, r=pnkfelix
[NLL] Suggest let binding
Closes #49821
Also adds an alternative to `explain_why_borrow_contains_point` that allows changing error messages based on the reason that will be given. This will also be useful for #51026, #51169 and maybe further changes to does not live long enough messages.
- #53218 (Add a implementation of `From` for converting `&'a Option<T>` into `Option<&'a T>`)
- #54024 (Fix compiling some rustc crates to wasm)
- #54095 (Rename all mentions of `nil` to `unit`)
- #54173 (Suggest valid crate type if invalid crate type is found)
- #54194 (Remove println!() statement from HashMap unit test)
- #54203 (Fix the stable release of os_str_str_ref_eq)
- #54207 (re-mark the never docs as unstable)
- #54210 (Update Cargo)
This stability attribute was removed in https://github.com/rust-lang/rust/pull/47630, but not replaced with a `#[stable]` attribute, and when https://github.com/rust-lang/rust/pull/50121 reverted that stabilization, it didn't set the docs back to unstable. I'm concerned as to why it was allowed to not have the stability attribute at all, but at least this can put it back.
I'm nominating this for beta backport because it's a really small change, and right now our docs are in an awkward position where the `!` type is technically unstable to use, but the docs don't say so the same way any other library feature would. (And this is also the case *on stable* now, but i'm not suggesting a stable backport for a docs fix.)
Rollup merge of #54024 - alexcrichton:compile-to-wasm, r=petrochenkov
Fix compiling some rustc crates to wasm
I was dabbling recently seeing what it would take to compile `rustfmt` to the
`wasm32-unknown-unknown` target and it turns out not much effort is needed!
Currently `rustfmt` depends on a few rustc crates published to crates.io, so
this commit touches up those crates to compile for wasm themselves. Notably:
* The `rustc_data_structures` crate's `flock` implementation is stubbed out to
unconditionally return errors on unsupported platforms.
* The `rustc_errors` crate is extended to not do any locking for all non-windows
platforms.
In both of these cases if we port the compiler to new platforms the
functionality isn't critical but will be discovered over time as it comes up, so
this hopefully doesn't make it too too hard to compile to new platforms!
- #53371 (Do not emit E0277 on incorrect tuple destructured binding)
- #53829 (Add rustc SHA to released DWARF debuginfo)
- #53950 (Allow for opting out of ThinLTO and clean up LTO related cli flag handling.)
- #53976 (Replace unwrap calls in example by expect)
- #54070 (Add Error::description soft-deprecation to RELEASES)
- #54076 (miri loop detector hashing)
- #54119 (Add some unit tests for find_best_match_for_name)
- #54147 (Add a test that tries to modify static memory at compile-time)
- #54150 (Updated 1.29 release notes with --document-private-items flag)
- #54163 (Update stage 0 to latest beta)
- #54170 (COMPILER_TESTS.md has been moved)