this commit implements the first step of the `default impl` feature:
all items in a `default impl` are (implicitly) `default` and hence
specializable.
In order to test this feature I've copied all the tests provided for the
`default` method implementation (in run-pass/specialization and
compile-fail/specialization directories) and moved the `default` keyword
from the item to the impl.
See referenced issue for further info
traits::select: quickly filter out predicates from other traits
this improves most pre-trans passes's performance by ~1%.
That missed the spring cleaning PR because I wanted to ship it.
r? @eddyb
In some cases (e.g. <[int-var] as Add<[int-var]>>), selection can turn up
a large number of candidates. Bailing out early avoids O(n^2) performance.
This improves item-type checking time by quite a bit, resulting in ~2% of total
time-to-typeck.
this avoids parsing item attributes on each call to `item_attrs`, which takes
off 33% (!) of translation time and 50% (!) of trans-item collection time.
That method is *incredibly* hot, so this ends up saving 10% of trans
time.
BTW, we really should be doing dependency tracking there - and possibly be
taking the respective perf hit (got to find a way to make DTMs fast), but
`layout_cache` is a non-dep-tracking map.
Refactor trans some more to pave way for incremental compilation
Various refactorings paving the way for the newer approach to incremental compilation (And, in particular, to "query-ifying" trans). My partial goal is to remove `SharedCrateContext`; this PR gets about as far as I can easily get before starting to really want the red/green algorithm.
r? @eddyb
cc @michaelwoerister
Implementation of repr struct alignment RFC 1358.
The main changes around rustc::ty::Layout::struct:
* Added abi_align field which stores abi alignment before repr align is applied
* align field contains transitive repr alignment
* Added padding vec which stores padding required after fields
The main user of this information is rustc_trans::adt::struct_llfields
which determines the LLVM fields to be used by LLVM, including padding
fields.
A possible future optimisation would be to put the padding Vec in an Option, since it will be unused unless you are using repr align.
Don't panic if an attribute macro fails to resolve at crate root
Adds temporary regression test; this ideally should work as-is (#41430)
Closes#41211
r? @jseyfried
Hopefully will fix assert on ARM where vector types are being used as
the fill type for enums containing repr aligned types greater than the
largest possible native type, thus don't match the Layout's alignment
and triggers an assert.
Arguably these could become custom queries, but I chose not to do that
because the relationship of queries and trait system is not yet fleshed
out enough. For now it seems fine to have them be `DepTrackingMap` using
the memoize pattern.
The symbol map is not good for incremental: it has inputs from every fn
in existence, and it will change if anything changes. One could imagine
cheating with the symbol-map and exempting it from the usual dependency
tracking, since the results are fully deterministic. Instead, I opted to
just add a per-CGU cache, on the premise that recomputing some symbol
names is not going to be so very expensive.
This may seem like overkill, but it's exactly what we want/need for
incremental compilation I think. In particular, while generating code
for some codegen unit X, we can wind up querying about any number of
external items, and we only want to be forced to rebuild X is some of
those changed from a foreign item to otherwise. Factoring this into a
query means we would re-run only if some `false` became `true` (or vice
versa).
rustc: replace TypeContents with two independent properties (is_freeze / needs_drop).
`InteriorUnsafe` / `interior_unsafe` was replaced with a private lang-item `Freeze` auto trait in libcore.
`OwnsDtor` / `needs_drop` was replaced with a specialized traversal that *doesn't* avoid caching results in case of a cycle, as the only cycles left can only occur in erroneous "types with infinite sizes", references and raw pointers not having destructors. Also, `Copy` is now checked at every step of the recursion.
r? @nikomatsakis
Expanded docs and examples for PathBuf::file_name and friends
This addresses some common surprises when `PathBuf::set_file_name` is called on the path of a directory rather than a file.
r? @steveklabnik
Use an (over-writable) environment variable for the `gdb` command
Instead of hard-coding the command to run, using the environment
variable `GDB_CMD` (that defaults to `gdb`) allows using a different
debugger than the default `gdb` executable.
This gives the possibility to use `cgdb` as the debugger, which provides
a nicer user interface. Note that one has to use `GDB_CMD="cgdb --"` to
use cgdb (note the trailing `--`) to let cgdb pass the proper arguments
to `gdb`.
Reduce visual clutter of multiline start when possible
When a span starts on a line with nothing but whitespace to the left,
and there are no other annotations in that line, simplify the visual
representation of the span.
Go from:
```rust
error[E0072]: recursive type `A` has infinite size
--> file2.rs:1:1
|
1 | struct A {
| _^ starting here...
2 | | a: A,
3 | | }
| |_^ ...ending here: recursive type has infinite size
|
```
To:
```rust
error[E0072]: recursive type `A` has infinite size
--> file2.rs:1:1
|
1 | / struct A {
2 | | a: A,
3 | | }
| |_^ recursive type has infinite size
```
Re: #38246.
r? @nikomatsakis CC @jonathandturner
When a span starts on a line with nothing but whitespace to the left,
and there are no other annotations in that line, simplify the visual
representation of the span.
Go from:
```rust
error[E0072]: recursive type `A` has infinite size
--> file2.rs:1:1
|
1 | struct A {
| _^ starting here...
2 | | a: A,
3 | | }
| |_^ ...ending here: recursive type has infinite size
|
```
To:
```rust
error[E0072]: recursive type `A` has infinite size
--> file2.rs:1:1
|
1 | / struct A {
2 | | a: A,
3 | | }
| |_^ recursive type has infinite size
```
Remove `starting here...`/`...ending here` labels from all multiline
diagnostics.
The main changes around rustc::ty::Layout::struct and rustc_trans:adt:
* Added primitive_align field which stores alignment before repr align
* Always emit field padding when generating the LLVM struct fields
* Added methods for adjusting field indexes from the layout index to the
LLVM struct field index
The main user of this information is rustc_trans::adt::struct_llfields
which determines the LLVM fields to be used by LLVM, including padding
fields.
Update `Child` docs to not have a note section
In #29370 it's noted that for "the Note shouldn't be one, and should come before
the examples." This commit changes the positioning of the section and removes
wording that said take note in order for it to flow better with the surrounding
text and it's new position.
specialize Extend for Vec with IntoIter
Before, `vec.extend(&other_vec)` was quite a bit faster than `vec.extend(other_vec)`. This allows extending by consuming a vec to use the same code as extending from a slice.
Override ToOwned::clone_into for Path and OsStr
The only non-overridden one remaining is the CStr impl, which cannot
be optimized as doing so would break CString's second invariant.
Follow-up to 7ec27ae (PR #41009).
r? @alexcrichton
rustc_trans: do not treat byval as using up registers.
Perhaps not that well-documented, `byval` pointer arguments *are not* the same as pointer arguments used by pass-by-ref, but rather the pointer is only used by LLVM to pass the *contents* on the stack.
Fixes#41375.
Fix ICE building gluon_vm
The problem was due to various places we were failing to propagate obligations. I think I got them mostly correct, but I didn't get around to writing test cases for each case.
r? @eddyb or @arielb1
Bump stage0 to fix ARM LLVM
There was a serious ARM codegen bug in LLVM that was fixed by #40779,
also backported to beta. This updates stage0 to 1.17.0-beta.3 to pick
up that change, so ARM can bootstrap natively again.
Fixes#41291
cc @arielb1
Add a way to get shorter spans until `char` for pointing at defs
```rust
error[E0072]: recursive type `X` has infinite size
--> file.rs:10:1
|
10 | struct X {
| ^^^^^^^^ recursive type has infinite size
|
= help: insert indirection (e.g., a `Box`, `Rc`, or `&`) at some point to make `X` representable
```
vs
```rust
error[E0072]: recursive type `X` has infinite size
--> file.rs:10:1
|
10 | struct X {
| _^ starting here...
11 | | x: X,
12 | | }
| |_^ ...ending here: recursive type has infinite size
|
= help: insert indirection (e.g., a `Box`, `Rc`, or `&`) at some point to make `X` representable
```
Re: #35965, #38246. Follow up to #38328.
r? @jonathandturner
Improve std::path docs
Fixes#29368.
This PR contains a pretty significant redistribution of some of the module docs to more appropriate places, as well as general expansion, clarification, and additional examples.
For more details, see the commit descriptions.
r? @steveklabnik
Add top level sections to the Unstable Book.
Prior to this commit, the contents of the Unstable Book were assumed to
be unstable features. This commit moves features into 'language features'
or 'library features' subsections. It also moves the 'linker_flavor'
compiler flag into a new 'Compiler Flags' subsection.
Even though it was helpful, I removed the tidy check that
cross-references the SUMMARY.md links with the Unstable Book directory
contents just because it would be difficult to maintain.
Relevant PR: https://github.com/rust-lang/rust/issues/41142.
Disable debuginfo when compiling tools
Currently the Cargo binary has jumped from 14M to 34M on the beta channel, which
appears to be due to the fact that we're compiling tools with debug information
inside them. This additionally means that the `rls` binary is 62M right now!
This wasn't an intentional change, so be sure to disable debuginfo when
compiling tools as it's just intended for the standard library and compile for
now.
Ban registering obligations during InferCtxt snapshots.
Back in #33852, a flag was added to `InferCtxt` to prevent rolling back a snapshot if obligations were added to some `FulfillmentContext` during the snapshot, to prevent leaking fresh inference variables (created during that snapshot, so their indices would get reused) in obligations, which could ICE or worse.
But that isn't enough in the long run, as type-checking ends up relying on success implying that eager side-effects are fine, and while stray obligations *do* get caught nowadays, those errors prevent, e.g. the speculative coercions from #37658, which *have to* be rolled back *even* if they succeed.
We can't just allow those obligations to stay around though, because we end up, again, in ICEs or worse.
Instead, this PR modifies `lookup_method_in_trait_adjusted` to return `InferOk` containing the obligations that `Autoderef::finalize_as_infer_ok` can propagate to deref coercions.
As there shouldn't be *anything* left that registers obligations during snapshots, it's completely banned.
r? @nikomatsakis @arielb1
Use the existing path when removing the prefix fails
This allows the use of out-of-tree paths to be specified. I found this while trying to build with a modified version of `rls-data`, which is currently pointing to a version on crates.io.
cc @alexcrichton
Also, it wasn't clear if I needed to add a test for this (or how). I didn't see any tests that took paths into consideration.
Move E0101 and E0102 logic into new E0282 mechanism #40013
Hello there!
## What's this?
Previously, me and @nikomatsakis worked on error messages of uninferred locals. (#38812)
This aims to build up on that by moving certain type checks from `writeback`.
With this, `E0101` and `E0102` errors are getting obsoleted and no longer thrown.
They're replaced with customized versions of `E0282`s instead.
## Sample Error Messages
#### `E0101` is getting converted into:
```rust
error[E0282]: type annotations needed
--> test.rs:2:14
|
2 | let x = |_| {};
| ^ consider giving this closure parameter a type
error: aborting due to previous error
```
#### `E0102` is getting converted into:
```rust
error[E0282]: type annotations needed
--> test.rs:2:9
|
2 | let x = [];
| ^
| |
| consider giving `x` a type
| cannot infer type for `[_; 0]`
error: aborting due to previous error
```
## Annoyances
- I think we need to change our way of type name resolving in relevant places, because that `[_; 0]` looks horrible IMHO.
- I'm not terribly happy with the note ordering of errors. So please do point to code that might help me accomplish this.
## Tests
Tests of `E0101` and `E0102` are getting converted from `compile-fail` to `ui` tests.
## Documentation
Please help me with documentation update. There are some confusing places that needed an update but I'm not sure if I did the right ones.
Please do comment on messages, layouts and other details.
## Appreciation
Huge thanks goes to @nikomatsakis for being a patient and humble mentor along this long journey. 🍻
Prior to this commit, the contents of the Unstable Book were assumed to
be unstable features. This commit moves features into 'language features'
or 'library features' subsections. It also moves the 'linker_flavor'
compiler flag into a new 'Compiler Flags' subsection.
Even though it was helpful, I removed the tidy check that
cross-references the SUMMARY.md links with the Unstable Book directory
contents just because it would be difficult to maintain.
Relevant PR: https://github.com/rust-lang/rust/issues/41142.
std: Back out backtrace pruning logic
It was discovered #40264 that this backtrace pruning logic is a little too
aggressive, so while we figure how out to handle #40264 this commit backs out
the changes to prune frames. Note that other cosmetic changes, such as better
path printing and such remain.
lower `move_val_init` during MIR construction
Because of its "magic" order-of-evaluation semantics, `move_val_init` must be lowered during MIR construction in order to work without needing a temporary.
r? @eddyb
convert calls to `visit_all_item_likes_in_krate`
We no longer need to track the tasks in these cases since these
particular tasks have no outputs (except, potentially, errors...) and
they always execute.
cc #40746
r? @eddyb
bootstrap: Don't workaround uname -m on Darwin
This no longer manifests on any versions of OSX that I could find.
How far back is Rust officially supported? I can try to get copies to test when this behaviour changed.
(Fun fact, at a minimum the comment already lies, since the flag is `-m` :))
Improve Process::spawn with piped stdio on Redox
- Adds `dup2`, and uses it for stdio piping
- Removes `O_CLOEXEC` from piped stdio, as `dup` on Redox does not disable O_CLOEXEC
Add `as_bytes()` for `FromUtf8Error`.
This change allows to obtain an underlying invalid UTF-8 bytes without `FromUtf8Error` destruction. Such method may be useful for example in a library that attempts to save both valid and invalid UTF-8 strings in some struct and to be able to provide immutable access to it without destruction.
Personally without this change I ended with `Result<String, (Vec<u8>, Utf8Error)`, which almost copies the functionality of `FromUtf8Error`, but allows immutable view access.
Instead of hard-coding the command to run, using the environment
variable `GDB_CMD` (that defaults to `gdb`) allows using a different
debugger than the default `gdb` executable.
This gives the possibility to use `cgdb` as the debugger, which provides
a nicer user interface. Note that one has to use `GDB_CMD="cgdb --"` to
use cgdb (note the trailing `--`) to let cgdb pass the proper arguments
to `gdb`.
There was a serious ARM codegen bug in LLVM that was fixed by #40779,
also backported to beta. This updates stage0 to 1.17.0-beta.3 to pick
up that change, so ARM can bootstrap natively again.
Fixes#41291
cc @arielb1
It was discovered #40264 that this backtrace pruning logic is a little too
aggressive, so while we figure how out to handle #40264 this commit backs out
the changes to prune frames. Note that other cosmetic changes, such as better
path printing and such remain.
Add functions to safely transmute float to int
The safe subset of Rust tries to be as powerful as possible. While it is very powerful already, its currently impossible to safely transmute integers to floats. While crates exist that provide a safe interface, most prominently the `iee754` crate (which also inspired naming of the added functions), they themselves only use the unsafe `mem::transmute` function to accomplish this task.
Also, including an entire crate for just two lines of unsafe code seems quite wasteful.
That's why this PR adds functions to safely transmute integers to floats and vice versa, currently gated by the newly added `float_bits_conv` feature.
The functions added are no niche case. Not just `ieee754` [currently implements](https://github.com/huonw/ieee754/blob/master/src/lib.rs#L441) float to int transmutation via unsafe code but also the [very popular `byteorder` crate](https://github.com/BurntSushi/byteorder/blob/1.0.0/src/lib.rs#L258). This functionality of byteorder is in turn used by higher level crates. I only give two examples out of many: [chor](a7363ea9aa/src/ser.rs (L227)) and [bincode](f06a4cfcb5/src/serde/reader.rs (L218)).
One alternative would be to manually use functions like pow or multiplication by 1 to get a similar result, but they only work in the int -> float direction, and are not bit exact, and much slower (also, most likely the optimizer will never optimize it to a transmute because the conversion is not bit exact while the transmute is).
Tracking issue: #40470
We no longer need to track the tasks in these cases since these
particular tasks have no outputs (except, potentially, errors...) and
they always execute.
[on-demand] Turn monomorphic_const_eval into a proper query, not just a cache.
The error definitions and reporting logic, alongside with `eval_length` were moved to `librustc`.
Both local and cross-crate constant evaluation is on-demand now, but the latter is only used for `enum` discriminants, to replace the manual insertion into the cache which was done when decoding variants.
r? @nikomatsakis
Rename compiler_barrier to compiler_fence
This addresses concerns raised following the merge of #41092. Specifically:
> The naming of these seems surprising: the multithreaded functions (and both the single and multithreaded intrinsics themselves) are fences, but this is a barrier. It's not incorrect, but the latter is both inconsistent with the existing functions and slightly confusing with another type in std (e.g., `Barrier`).
`compiler_fence` carries the same semantic implication that this is a compiler-only operation, while being more in line with the fence/barrier concepts already in use in `std`.
Currently the Cargo binary has jumped from 14M to 34M on the beta channel, which
appears to be due to the fact that we're compiling tools with debug information
inside them. This additionally means that the `rls` binary is 62M right now!
This wasn't an intentional change, so be sure to disable debuginfo when
compiling tools as it's just intended for the standard library and compile for
now.
Part of #29368.
* Added a new summary paragraph about std::path's parsing facilities
* Slightly exanded `Component`'s docs
* removed the now redundant section on component types from the module docs
* moved the section on path normalization during parsing to the docs on
`Path::components`
* Clarified difference between `Prefix` and `PrefixComponent` in their
respecive summary sentences
Hoedown big comeback!
```bash
> cargo +local test
Compiling libc v0.2.20
Compiling sysinfo v0.3.4 (file:///Users/imperio/rust/sysinfo)
Finished dev [unoptimized + debuginfo] target(s) in 3.2 secs
Running target/debug/deps/disk_list-dbd70897f1f7e080
running 1 test
test test_disks ... ok
test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured
Running target/debug/deps/sysinfo-8ad11103abdf5941
running 0 tests
test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured
Doc-tests sysinfo
WARNING: src/sysinfo.rs - (line 45) test will be run in the next rustdoc version. If it's not supposed to, please update your documentation and make it compliant to common mark specifications.
WARNING: src/sysinfo.rs - (line 48) test will be run in the next rustdoc version. If it's not supposed to, please update your documentation and make it compliant to common mark specifications.
running 1 test
test src/sysinfo.rs - (line 14) ... ok
test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured
```
r? @rust-lang/docs
:vis matcher for macro_rules
Resurrection of @DanielKeep's implementation posted with [RFC 1575](https://github.com/rust-lang/rfcs/pull/1575).
@jseyfried was of the opinion that this doesn't need an RFC.
Needed before merge:
- [x] sign-off from @DanielKeep since I stole his code
- [x] feature gate
- [x] docs
Eduard-Mihai Burtescu
Matt Ickstadt
Jessica Hamilton
Guillaume Gomez
steveklabnik
Gianni Ciccarelli
Without Boats
Scott McMurray
Simon Sapin
bors
Ariel Ben-Yehuda
Tim Neumann
Corey Farwell
Ariel Ben-Yehuda
Niko Matsakis
Cameron Hart
Vadim Petrochenkov
Tobias Bucher
Josh Stone
Esteban Küber
Austin Bonander
Marco A L Barbosa
Matt Brubeck
Nicolas Bigaouette
Sean McArthur
Michael Gattozzi
Alex Burka
Oliver Middleton
Cengiz Can
Alex Crichton
lukaramu
Richo Healey
est31
Dylan Maccora
Diggory Blake
QuietMisdreavus
alexey zabelin
Evgeny Safronov
