Auto merge of #62335 - Mark-Simulacrum:rollup-0pcaz5a, r=Mark-Simulacrum
Rollup of 15 pull requests
Successful merges:
- #62021 (MSVC link output improve)
- #62064 (nth_back for chunks_exact)
- #62128 (Adjust warning of -C extra-filename with -o.)
- #62161 (Add missing links for TryFrom docs)
- #62183 (std: Move a process test out of libstd)
- #62186 (Add missing type urls in Into trait)
- #62196 (Add Vec::leak)
- #62199 (import gdb for explicit access to gdb.current_objfile())
- #62229 (Enable intptrcast for explicit casts)
- #62250 (Improve box clone doctests to ensure the documentation is valid)
- #62255 (Switch tracking issue for `#![feature(slice_patterns)]`)
- #62285 (Fix michaelwoerister's mailmap)
- #62304 (HashMap is UnwindSafe)
- #62319 (Fix mismatching Kleene operators)
- #62327 (Fixed document bug, those replaced each other)
Mark Rousskov [Wed, 3 Jul 2019 13:59:28 +0000 (09:59 -0400)]
Rollup merge of #62304 - SimonSapin:safe, r=eddyb
HashMap is UnwindSafe
Fixes https://github.com/rust-lang/rust/issues/62301, a regression in 1.36.0-pre which was caused by hashbrown using `NonZero<T>` where the older hashmap used `Unique<T>`.
Mark Rousskov [Wed, 3 Jul 2019 13:59:16 +0000 (09:59 -0400)]
Rollup merge of #62183 - alexcrichton:fix-tests, r=nikomatsakis
std: Move a process test out of libstd
This commit moves a test out of libstd which is causing deadlocks on
musl on CI. Looks like the recent update in musl versions brings in some
internal updates to musl which makes `setgid` and `setuid` invalid to
call after a `fork` in a multithreaded program. The issue seen here is
that the child thread was attempting to grab a lock held by a
nonexistent thread, meaning that the child process simply deadlocked
causing the whole test to deadlock.
This commit moves the test to its own file with no threads which should
work.
Mark Rousskov [Wed, 3 Jul 2019 13:59:13 +0000 (09:59 -0400)]
Rollup merge of #62128 - ehuss:extra-filename-warning, r=matthewjasper
Adjust warning of -C extra-filename with -o.
If `--emit` includes multiple unnamed outputs, and `-o` was specified, and `-C extra-filename` was specified, the compiler would warn that `-C extra-filename` was ignored, but this is not true. The "adapting" of the filenames includes the extra-filename info.
Since this is a little convoluted and hard to follow, here is a little chart to summarize when running with `rustc foo.rs -o xyz -C extra-filename=asdf`
`--emit` | Result
---------|--------
`link` | `xyz` (extra-filename ignored)
`link,dep-info` | `xyzasdf`, `xyzasdf.d` (this PR removes the incorrect warning)
As to whether or not this behavior is the best choice is another question.
Auto merge of #61995 - eddyb:hir-sep-ptr, r=petrochenkov
rustc: use a separate copy of P for HIR than for AST.
Note: this currently includes/is based on top of #61987.
Like #61968, but goes one step further and uses a separate `P<...>` for the HIR, with no `Clone`, or the ability to mutate after allocation.
There is still `into_inner`/`into_iter`, but they're only exposed for `hir::lowering`, and they would take more work to untangle.
Auto merge of #61775 - nikomatsakis:issue-56238-multiple-lifetimes-async-fn-region-solver, r=MatthewJasper
generalize impl trait to permit multiple lifetime bounds
Generalizes the region solver to support "pick constraints". These have the form:
```
pick R0 from [R1..Rn]
```
where `R1..Rn` are called the "option regions". The idea is that `R0` must be equal to *some* region in the set `R1..Rn`. These constraints are then used to handle cases like this:
The problem here is that every region R in the hidden type must be equal to *either* `'a` *or* `'b` (or `'static`) -- in the past, the only kinds of constraints we had were outlives constraints, and since `'a` and `'b` are unrelated, there was no outlives constraint we could issue that would enforce that (`R: 'a` and `R: 'b` are both too strict, for example). But now we can issue a pick constraint: `pick R from ['a, 'b]`.
In general, solving pick constraints is tricky. We integrate them into the solver as follows. In general, during the propagation phase, we are monotonically growing a set of inference regions. To handle a case like `pick R from [O...]`, where `O...` represents the option regions, we do the following:
- Look for all the *lower bounds* of the region R -- that is, every region LB such that `R: LB` must hold.
- Look for all the *upper bounds* of the region R -- that is, every region UB such that `UB: R` must hold.
- Let the *viable options* be each option region O such that `UB: O` and `O: LB` for each UB, LB bound.
- Find the *minimal viable option* M, where `O: M` holds for every option region O.
If there is such a *minimal viable option*, then we make `R: M`. (This may in turn influence other bits of inference.) If there is no minimal viable option, either because all options were eliminated or because none of the remaining options are minimal, we do nothing. Ultimately, if the pick constraint is not satisfied, an error is reported.
For this logic, we currently require that the option regions O are always lifetime parameters. To determine the bounds, we walk the various outlives edges that were otherwise introduced.
r? @matthewjasper
cc @cramertj
Fixes #56238
TODO:
- [ ] Error messages include region variable info sometimes, how to fix?
- [ ] Tests for bare `existential type` and other impl Trait usage
Auto merge of #61268 - michaelwoerister:stabilize-pgo, r=alexcrichton
Stabilize support for Profile-guided Optimization
This PR makes profile-guided optimization available via the `-C profile-generate` / `-C profile-use` pair of commandline flags and adds end-user documentation for the feature to the [rustc book](https://doc.rust-lang.org/rustc/). The PR thus ticks the last two remaining checkboxes of the [stabilization tracking issue](https://github.com/rust-lang/rust/issues/59913).
From the tracking issue:
> Profile-guided optimization (PGO) is a common optimization technique for ahead-of-time compilers. It works by collecting data about a program's typical execution (e.g. probability of branches taken, typical runtime values of variables, etc) and then uses this information during program optimization for things like inlining decisions, machine code layout, or indirect call promotion.
If you are curious about how this can be used, there is a rendered version of the documentation this PR adds available [here](
https://github.com/michaelwoerister/rust/blob/stabilize-pgo/src/doc/rustc/src/profile-guided-optimization.md).
Simon Sapin [Tue, 2 Jul 2019 13:19:19 +0000 (15:19 +0200)]
HashMap is UnwindSafe
Fixes https://github.com/rust-lang/rust/issues/62301, a regression in 1.36.0 which was caused by hashbrown using `NonZero<T>` where the older hashmap used `Unique<T>`.
Auto merge of #61922 - tmandry:moar-generator-optimization, r=matthewjasper
Don't store locals that have been moved from in generators
This avoids reserving storage in generators for locals that are moved
out of (and not re-initialized) prior to yield points. Fixes #59123.
This adds a new dataflow analysis, `RequiresStorage`, to determine whether the storage of a local can be destroyed without being observed by the program. The rules are:
1. StorageLive(x) => mark x live
2. StorageDead(x) => mark x dead
3. If a local is moved from, _and has never had its address taken_, mark it dead
4. If (any part of) a local is initialized, mark it live'
This is used to determine whether to save a local in the generator object at all, as well as which locals can be overlapped in the generator layout.
Here's the size in bytes of all testcases included in the change, before and after the change:
async fn test |Size before |Size after
-----------------|------------|----------
single | 1028 | 1028
single_with_noop | 2056 | 1032
joined | 5132 | 3084
joined_with_noop | 8208 | 3084
generator test |Size before |Size after
----------------------------|------------|----------
move_before_yield | 1028 | 1028
move_before_yield_with_noop | 2056 | 1032
overlap_move_points | 3080 | 2056
## Future work
Note that there is a possible extension to this optimization, which modifies rule 3 to read: "If a local is moved from, _**and either has never had its address taken, or is Freeze and has never been mutably borrowed**_, mark it dead." This was discussed at length in #59123 and then #61849. Because this would cause some behavior to be UB which was not UB before, it's a step that needs to be taken carefully.
A more immediate priority for me is inlining `std::mem::size_of_val(&x)` so it becomes apparent that the address of `x` is not taken. This way, using `size_of_val` to look at the size of your inner futures does not affect the size of your outer future.
cc @cramertj @eddyb @Matthias247 @nikomatsakis @RalfJung @Zoxc
Auto merge of #62279 - pietroalbini:fix-azure-crlf, r=alexcrichton
ci: explicitly disable CRLF conversion on Windows
The Azure image enables CRLF conversion on Windows builders, but that caused regressions both in our test suite (the miri test suite broke) and in the ecosystem, since we started shipping install scripts with CRLF endings instead of the old LF. The [Godbolt Compiler Explorer](https://godbolt.org/) is one such case of breakage.
This adds a step to the build explicitly disabling the conversion before the repository is checked out.
Pietro Albini [Mon, 1 Jul 2019 19:57:08 +0000 (21:57 +0200)]
ci: explicitly disable CRLF conversion on Windows
The Azure image enables CRLF conversion on Windows builders, but that
caused regressions both in our test suite (the miri test suite broke)
and in the ecosystem, since we started shipping install scripts with
CRLF endings instead of the old LF. The Godbolt Compiler Explorer is one
such case of breakage.
This adds a step to the build explicitly disabling the conversion before
the repository is checked out.
projects / rust.git / log