Commit Graph

155932 Commits

Author SHA1 Message Date
John Kugelman
a990c76d84 Optimize File::read_to_end and read_to_string
Reading a file into an empty vector or string buffer can incur
unnecessary `read` syscalls and memory re-allocations as the buffer
"warms up" and grows to its final size. This is perhaps a necessary evil
with generic readers, but files can be read in smarter by checking the
file size and reserving that much capacity.

`std::fs::read` and `read_to_string` already perform this optimization:
they open the file, reads its metadata, and call `with_capacity` with
the file size. This ensures that the buffer does not need to be resized
and an initial string of small `read` syscalls.

However, if a user opens the `File` themselves and calls
`file.read_to_end` or `file.read_to_string` they do not get this
optimization.

```rust
let mut buf = Vec::new();
file.read_to_end(&mut buf)?;
```

I searched through this project's codebase and even here are a *lot* of
examples of this. They're found all over in unit tests, which isn't a
big deal, but there are also several real instances in the compiler and
in Cargo. I've documented the ones I found in a comment here:

https://github.com/rust-lang/rust/issues/89516#issuecomment-934423999

Most telling, the `Read` trait and the `read_to_end` method both show
this exact pattern as examples of how to use readers. What this says to
me is that this shouldn't be solved by simply fixing the instances of it
in this codebase. If it's here it's certain to be prevalent in the wider
Rust ecosystem.

To that end, this commit adds specializations of `read_to_end` and
`read_to_string` directly on `File`. This way it's no longer a minor
footgun to start with an empty buffer when reading a file in.

A nice side effect of this change is that code that accesses a `File` as
a bare `Read` constraint or via a `dyn Read` trait object will benefit.
For example, this code from `compiler/rustc_serialize/src/json.rs`:

```rust
pub fn from_reader(rdr: &mut dyn Read) -> Result<Json, BuilderError> {
    let mut contents = Vec::new();
    match rdr.read_to_end(&mut contents) {
```

Related changes:

- I also added specializations to `BufReader` to delegate to
  `self.inner`'s methods. That way it can call `File`'s optimized
  implementations if the inner reader is a file.

- The private `std::io::append_to_string` function is now marked
  `unsafe`.

- `File::read_to_string` being more efficient means that the performance
  note for `io::read_to_string` can be softened. I've added @camelid's
  suggested wording from:

  https://github.com/rust-lang/rust/issues/80218#issuecomment-936806502
2021-10-07 18:42:02 -04:00
Noah Lev
9771803934 Update Miri 2021-10-07 13:47:00 -07:00
Matthias Krüger
ff6601e0fc some clippy::perf fixes 2021-10-07 22:31:33 +02:00
bors
485ced56b8 Auto merge of #89617 - flip1995:clippyup, r=Manishearth
Update Clippy

r? `@Manishearth`
2021-10-07 20:26:27 +00:00
asquared31415
271da7d8bc make #[target_feature] work with asm register classes 2021-10-07 15:42:18 -04:00
Eliza Weisman
0e79545c30
lol i forgot the syntax for my own crate's macros
T_____T

Signed-off-by: Eliza Weisman <eliza@buoyant.io>
2021-10-07 12:03:15 -07:00
Eliza Weisman
b6f09a19b2
comma-related changes
Signed-off-by: Eliza Weisman <eliza@buoyant.io>
2021-10-07 11:29:47 -07:00
Michael Woerister
b7cc99142a Turn tcx.vtable_allocation() into a query. 2021-10-07 20:03:00 +02:00
Eliza Weisman
e00eac8b9c
use structured fields in some existing warnings
Signed-off-by: Eliza Weisman <eliza@buoyant.io>
2021-10-07 10:48:48 -07:00
Eliza Weisman
928c787fce
make them structured while i'm here
Signed-off-by: Eliza Weisman <eliza@buoyant.io>
2021-10-07 10:46:47 -07:00
Eliza Weisman
01803025d2
demote rustc_peek traces look not user-facing
Signed-off-by: Eliza Weisman <eliza@buoyant.io>
2021-10-07 10:45:39 -07:00
Jane Lusby
8965b5884a
Revert "Stabilize Iterator::intersperse()" 2021-10-07 10:39:36 -07:00
bors
5641481ad7 Auto merge of #89629 - GuillaumeGomez:rollup-s4r8me6, r=GuillaumeGomez
Rollup of 7 pull requests

Successful merges:

 - #89298 (Issue 89193 - Fix ICE when using `usize` and `isize` with SIMD gathers )
 - #89461 (Add `deref_into_dyn_supertrait` lint.)
 - #89477 (Move items related to computing diffs to a separate file)
 - #89559 (RustWrapper: adapt for LLVM API change)
 - #89585 (Emit item no type error even if type inference fails)
 - #89596 (Make cfg imply doc(cfg))
 - #89615 (Add InferCtxt::with_opaque_type_inference to get_body_with_borrowck_facts)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup
2021-10-07 17:17:25 +00:00
Eliza Weisman
eb67bf9368
Update compiler/rustc_driver/src/lib.rs
Co-authored-by: Joshua Nelson <github@jyn.dev>
2021-10-07 09:52:51 -07:00
Eliza Weisman
e7f04857ef
rustc_driver: Enable the WARN log level by default
This commit changes the `tracing_subscriber` initialization in
`rustc_driver` so that the `WARN` verbosity level is enabled by default
when the `RUSTC_LOG` env variable is empty. If the `RUSTC_LOG` env
variable is set, the filter string in the environment variable is
honored, instead.

Fixes #76824
Closes #89623

cc @eddyb, @oli-obk
2021-10-07 09:23:42 -07:00
Hans Kratz
6162fc0c80 Add wrapper for -Z gcc-ld=lld to invoke rust-lld with the correct flavor
The wrapper is installed as `ld` and `ld64` in the `lib\rustlib\<host_target>\bin\gcc-ld`
directory and its sole purpose is to invoke `rust-lld` in the parent directory with
the correct flavor.
2021-10-07 16:59:13 +02:00
Guillaume Gomez
0fbb011eb4
Rollup merge of #89615 - willcrichton:fix-get-body-with-borrowck-facts, r=oli-obk
Add InferCtxt::with_opaque_type_inference to get_body_with_borrowck_facts

`mir_borrowck` uses `with_opaque_type_inference` before calling `do_mir_borrowck`: 0eabf25b90/compiler/rustc_borrowck/src/lib.rs (L132)

However `get_body_with_borrowck_facts` does not. Therefore I get an ICE eg when calling this function on the bodies of an async function as described here: https://rust-lang.zulipchat.com/#narrow/stream/182449-t-compiler.2Fhelp/topic/.E2.9C.94.20ICE.20when.20using.20get_body_with_borrowck_facts.20with.20async

This change fixes that bug.

r? `@nikomatsakis`
2021-10-07 16:24:54 +02:00
Guillaume Gomez
e32328bdc5
Rollup merge of #89596 - GuillaumeGomez:implicit-doc-cfg, r=jyn514
Make cfg imply doc(cfg)

This is a reopening of #79341, rebased and modified a bit (we made a lot of refactoring in rustdoc's types so they needed to be reflected in this PR as well):

 * `hidden_cfg` is now in the `Cache` instead of `DocContext` because `cfg` information isn't stored anymore on `clean::Attributes` type but instead computed on-demand, so we need this information in later parts of rustdoc.
 * I removed the `bool_to_options` feature (which makes the code a bit simpler to read for `SingleExt` trait implementation.
 * I updated the version for the feature.

There is only one thing I couldn't figure out: [this comment](https://github.com/rust-lang/rust/pull/79341#discussion_r561855624)

> I think I'll likely scrap the whole `SingleExt` extension trait as the diagnostics for 0 and >1 items should be different.

How/why should they differ?

EDIT: this part has been solved, the current code was fine, just needed a little simplification.

cc `@Nemo157`
r? `@jyn514`

Original PR description:

This is only active when the `doc_cfg` feature is active.

The implicit cfg can be overridden via `#[doc(cfg(...))]`, so e.g. to hide a `#[cfg]` you can use something like:

```rust
#[cfg(unix)]
#[doc(cfg(all()))]
pub struct Unix;
```

By adding `#![doc(cfg_hide(foobar))]` to the crate attributes the cfg `#[cfg(foobar)]` (and _only_ that _exact_ cfg) will not be implicitly treated as a `doc(cfg)` to render a message in the documentation.
2021-10-07 16:24:53 +02:00
Guillaume Gomez
de0b4f9444
Rollup merge of #89585 - nbdd0121:issue-89574, r=estebank
Emit item no type error even if type inference fails

Fix #89574

The stashed error should be emitted regardless whether ty references error or not.
2021-10-07 16:24:52 +02:00
Guillaume Gomez
110d289846
Rollup merge of #89559 - krasimirgg:llvm-14-fatal_error_handler_t, r=nagisa
RustWrapper: adapt for LLVM API change

No functional changes intended.

The LLVM commit
e463b69736
changed an argument of fatal_error_handler_t from std::string to char*.
This adapts RustWrapper accordingly.
2021-10-07 16:24:51 +02:00
Guillaume Gomez
48548c91d6
Rollup merge of #89477 - Nicholas-Baron:compute_diff_rs, r=Mark-Simulacrum
Move items related to computing diffs to a separate file

Work towards #89475.
2021-10-07 16:24:50 +02:00
Guillaume Gomez
ab276b82b0
Rollup merge of #89461 - crlf0710:dyn_upcasting_lint, r=nikomatsakis
Add `deref_into_dyn_supertrait` lint.

Initial implementation of #89460. Resolves #89190.
Maybe also worth a beta backport if necessary.

r? `@nikomatsakis`
2021-10-07 16:24:49 +02:00
Guillaume Gomez
1584b6a796
Rollup merge of #89298 - gcohara:issue89193, r=workingjubilee
Issue 89193 - Fix ICE when using `usize` and `isize` with SIMD gathers

closes #89193
r? `@workingjubilee`
2021-10-07 16:24:48 +02:00
bors
0157cc977f Auto merge of #89534 - camsteffen:diag-name, r=oli-obk
Introduce `tcx.get_diagnostic_name`

Introduces a "reverse lookup" for diagnostic items. This is mainly intended for `@rust-lang/clippy` which often does a long series of `is_diagnostic_item` calls for the same `DefId`.

r? `@oli-obk`
2021-10-07 14:22:16 +00:00
Mara Bos
fcd9fa9099 Add tests for panic and [debug_]assert in Rust 2021. 2021-10-07 14:27:08 +02:00
Mara Bos
afe5335b97 Use correct edition for panic in [debug_]assert!() etc. 2021-10-07 14:27:08 +02:00
bors
680ff86391 Auto merge of #86525 - shamatar:array_len_opt, r=oli-obk
Array `.len()` MIR optimization pass

This pass kind-of works back the `[T; N].len()` call that at the moment is first coerced as `&[T; N]` -> `&[T]` and then uses `&[T].len()`. Depends on #86383
2021-10-07 11:34:40 +00:00
Michael Woerister
a1e2c0f0ad Remove untracked vtable-const-allocation cache from tcx 2021-10-07 11:27:35 +02:00
flip1995
333a06af42
Merge commit 'b7f3f7f6082679da2da9a0b3faf1b5adef3afd3b' into clippyup 2021-10-07 11:21:30 +02:00
bors
b7f3f7f608 Auto merge of #7783 - flip1995:rustup, r=flip1995
Rustup

r? `@ghost`

Finally an easy, conflict free rustup again 🎉

changelog: none
2021-10-07 09:18:25 +00:00
flip1995
8f9ef87f75
Bump nightly version -> 2021-10-07 2021-10-07 11:12:27 +02:00
flip1995
9613df9c85
Allow invalid-paths for regex paths 2021-10-07 11:12:02 +02:00
flip1995
1f955158dd
Merge remote-tracking branch 'upstream/master' into rustup 2021-10-07 11:11:23 +02:00
bors
ca8078d7b2 Auto merge of #89495 - Mark-Simulacrum:add-inlines, r=michaelwoerister
Add two inline annotations for hot functions

These two functions are essentially no-ops (and compile to just a load and
return), but show up in process_obligations profiles with a high call count --
so worthwhile to try and inline them. This is not normally possible as they're
non-generic, so they don't get offered for inlining by our current algorithm.
2021-10-07 06:23:23 +00:00
bors
01ea06acb7 Auto merge of #7780 - mikerite:update_lints_mod_revert, r=llogiq
Revert `update_lints` module list generating code

This commit reverts the module list generation code to what it was
before the change to `include!` it and generates better output.

changelog: none
2021-10-07 05:00:53 +00:00
Michael Wright
8f075ec961 Revert update_lints module list generating code
This commit reverts the module list generation code to what it was
before the change to `include!` it and generates better output.
2021-10-07 06:42:21 +02:00
bors
d3e6770efb Auto merge of #89454 - erikdesjardins:perfattrcheck, r=nikomatsakis
perf: only check for `rustc_trivial_field_reads` attribute on traits, not items, impls, etc.

The checks that are removed in this PR (originally added in #85200) caused a small perf regression: https://github.com/rust-lang/rust/pull/88824#issuecomment-932664761

Since the attribute is currently only applied to traits, I don't think it's worth keeping the additional checks for now.
If/when we decide to apply the attribute somewhere else, we can (partially) revert this and reevaluate the perf impact.

r? `@nikomatsakis` cc `@FabianWolff`
2021-10-07 03:42:05 +00:00
Will Crichton
549a68b73e Add InferCtxt::with_opaque_type_inference to get_body_with_borrowck_facts 2021-10-06 19:07:56 -07:00
bors
0eabf25b90 Auto merge of #89608 - Manishearth:rollup-m7kd76f, r=Manishearth
Rollup of 12 pull requests

Successful merges:

 - #87601 (Add functions to add unsigned and signed integers)
 - #88523 (Expand documentation for `FpCategory`.)
 - #89050 (refactor: VecDeques Drain fields to private)
 - #89245 (refactor: make VecDeque's IterMut fields module-private, not just crate-private)
 - #89324 (Rename `std:🧵:available_conccurrency` to `std:🧵:available_parallelism`)
 - #89329 (print-type-sizes: skip field printing for primitives)
 - #89501 (Note specific regions involved in 'borrowed data escapes' error)
 - #89506 (librustdoc: Use correct heading levels.)
 - #89528 (Fix suggestion to borrow when casting from pointer to reference)
 - #89531 (library std, libc dependency update)
 - #89588 (Add a test for generic_const_exprs)
 - #89591 (fix: alloc-optimisation is only for rust llvm)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup
2021-10-06 20:17:28 +00:00
Michael Benfield
a17193dbb9 Enable AutoFDO.
This largely involves implementing the options debug-info-for-profiling
and profile-sample-use and forwarding them on to LLVM.

AutoFDO can be used on x86-64 Linux like this:
rustc -O -Cdebug-info-for-profiling main.rs -o main
perf record -b ./main
create_llvm_prof --binary=main --out=code.prof
rustc -O -Cprofile-sample-use=code.prof main.rs -o main2

Now `main2` will have feedback directed optimization applied to it.

The create_llvm_prof tool can be obtained from this github repository:
https://github.com/google/autofdo

Fixes #64892.
2021-10-06 19:36:52 +00:00
Manish Goregaokar
f31c805038
Rollup merge of #89591 - infinity0:master, r=Amanieu
fix: alloc-optimisation is only for rust llvm

As discussed at the bottom of #83485.

On a separate note I'll take this chance ask, is it worth pulling in that patch (to recognise `__rust_dealloc`) into Debian's system LLVM? The main factors for us to consider would be (1) is the optimisation significant and (2) is there not any significant negative impact to non-rust packages that use LLVM.
2021-10-06 12:33:24 -07:00
Manish Goregaokar
eb7da35d84
Rollup merge of #89588 - BoxyUwU:add_a_test_uwu, r=lcnr
Add a test for generic_const_exprs

Test that const_eval_resolve evaluates consts with unused inference vars in substs

r? ``@lcnr``
2021-10-06 12:33:23 -07:00
Manish Goregaokar
79a1fc8419
Rollup merge of #89531 - devnexen:stack_overflow_bsd_libc_upd, r=dtolnay
library std, libc dependency update

to solve #87528 build.
2021-10-06 12:33:22 -07:00
Manish Goregaokar
f5bfa3450a
Rollup merge of #89528 - FabianWolff:issue-89497, r=jackh726
Fix suggestion to borrow when casting from pointer to reference

Fixes #89497.
2021-10-06 12:33:21 -07:00
Manish Goregaokar
7d6feb421e
Rollup merge of #89506 - yaymukund:docblock-headings, r=GuillaumeGomez
librustdoc: Use correct heading levels.

Closes #89309

This fixes the `<h#>` header tags throughout the docs to reflect a semantic hierarchy.

- I ran a script to manually check that we don't have any files with multiple `<h1>` tags.
- Also checked that we never incorrectly nest e.g. a `<h2>` under an `<h3>`.
- I also spot-checked a bunch of pages (`trait.Read`, `enum.Ordering`, `primitive.isize`, `trait.Iterator`).
2021-10-06 12:33:20 -07:00
Manish Goregaokar
b01594051c
Rollup merge of #89501 - Aaron1011:escaping-name-regions, r=davidtwco
Note specific regions involved in 'borrowed data escapes' error

Fixes #67007

Currently, a 'borrowed data escapes' error does not mention
the specific lifetime involved (except indirectly through a suggestion
about adding a lifetime bound). We now explain the specific lifetime
relationship that failed to hold, which improves otherwise vague
error messages.
2021-10-06 12:33:19 -07:00
Manish Goregaokar
b87a9a8a7c
Rollup merge of #89329 - tmiasko:print-type-sizes-no-fields, r=jackh726
print-type-sizes: skip field printing for primitives

Fixes #86528.
2021-10-06 12:33:18 -07:00
Manish Goregaokar
b4615b5bf9
Rollup merge of #89324 - yoshuawuyts:hardware-parallelism, r=m-ou-se
Rename `std:🧵:available_conccurrency` to `std:🧵:available_parallelism`

_Tracking issue: https://github.com/rust-lang/rust/issues/74479_

This PR renames  `std:🧵:available_conccurrency` to `std:🧵:available_parallelism`.

## Rationale

The API was initially named `std:🧵:hardware_concurrency`, mirroring the [C++ API of the same name](https://en.cppreference.com/w/cpp/thread/thread/hardware_concurrency). We eventually decided to omit any reference to the word "hardware" after [this comment](https://github.com/rust-lang/rust/pull/74480#issuecomment-662045841). And so we ended up with `available_concurrency` instead.

---

For a talk I was preparing this week I was reading through ["Understanding and expressing scalable concurrency" (A. Turon, 2013)](http://aturon.github.io/academic/turon-thesis.pdf), and the following passage stood out to me (emphasis mine):

> __Concurrency is a system-structuring mechanism.__ An interactive system that deals with disparate asynchronous events is naturally structured by division into concurrent threads with disparate responsibilities. Doing so creates a better fit between problem and solution, and can also decrease the average latency of the system by preventing long-running computations from obstructing quicker ones.

> __Parallelism is a resource.__ A given machine provides a certain capacity for parallelism, i.e., a bound on the number of computations it can perform simultaneously. The goal is to maximize throughput by intelligently using this resource. For interactive systems, parallelism can decrease latency as well.

_Chapter 2.1: Concurrency is not Parallelism. Page 30._

---

_"Concurrency is a system-structuring mechanism. Parallelism is a resource."_ — It feels like this accurately captures the way we should be thinking about these APIs. What this API returns is not "the amount of concurrency available to the program" which is a property of the program, and thus even with just a single thread is effectively unbounded. But instead it returns "the amount of _parallelism_ available to the program", which is a resource hard-constrained by the machine's capacity (and can be further restricted by e.g. operating systems).

That's why I'd like to propose we rename this API from `available_concurrency` to `available_parallelism`. This still meets the criteria we previously established of not attempting to define what exactly we mean by "hardware", "threads", and other such words. Instead we only talk about "concurrency" as an abstract resource available to our program.

r? `@joshtriplett`
2021-10-06 12:33:17 -07:00
Manish Goregaokar
14da7fc9ae
Rollup merge of #89245 - DeveloperC286:iter_mut_fields_to_private, r=joshtriplett
refactor: make VecDeque's IterMut fields module-private, not just crate-private

Made the fields of VecDeque's IterMut private by creating a IterMut::new(...) function to create a new instance of IterMut and migrating usage to use IterMut::new(...).
2021-10-06 12:33:16 -07:00
Manish Goregaokar
91e3b5172c
Rollup merge of #89050 - DeveloperC286:drain_fields_to_private, r=joshtriplett
refactor: VecDeques Drain fields to private

Made the fields of VecDeque's Drain private by creating a Drain::new(...) function to create a new instance of Drain and migrating usage to use Drain::new(...).
2021-10-06 12:33:15 -07:00