rustc: Load the `rustc_trans` crate at runtime
Building on the work of #45684 this commit updates the compiler to
unconditionally load the `rustc_trans` crate at runtime instead of linking to it
at compile time. The end goal of this work is to implement #46819 where rustc
will have multiple backends available to it to load.
This commit starts off by removing the `extern crate rustc_trans` from the
driver. This involved moving some miscellaneous functionality into the
`TransCrate` trait and also required an implementation of how to locate and load
the trans backend. This ended up being a little tricky because the sysroot isn't
always the right location (for example `--sysroot` arguments) so some extra code
was added as well to probe a directory relative to the current dll (the
rustc_driver dll).
Rustbuild has been updated accordingly as well to have a separate compilation
invocation for the `rustc_trans` crate and assembly it accordingly into the
sysroot. Finally, the distribution logic for the `rustc` package was also
updated to slurp up the trans backends folder.
A number of assorted fallout changes were included here as well to ensure tests
pass and such, and they should all be commented inline.
Building on the work of # 45684 this commit updates the compiler to
unconditionally load the `rustc_trans` crate at runtime instead of linking to it
at compile time. The end goal of this work is to implement # 46819 where rustc
will have multiple backends available to it to load.
This commit starts off by removing the `extern crate rustc_trans` from the
driver. This involved moving some miscellaneous functionality into the
`TransCrate` trait and also required an implementation of how to locate and load
the trans backend. This ended up being a little tricky because the sysroot isn't
always the right location (for example `--sysroot` arguments) so some extra code
was added as well to probe a directory relative to the current dll (the
rustc_driver dll).
Rustbuild has been updated accordingly as well to have a separate compilation
invocation for the `rustc_trans` crate and assembly it accordingly into the
sysroot. Finally, the distribution logic for the `rustc` package was also
updated to slurp up the trans backends folder.
A number of assorted fallout changes were included here as well to ensure tests
pass and such, and they should all be commented inline.
For E0277 on `for` loops, point at the "head" expression
When E0277's span points at a `for` loop, the actual issue is in the
element being iterated. Instead of pointing at the entire loop, point
only at the first line (when possible) so that the span ends in the
element for which E0277 was triggered.
[perf] Use std based dedup in projection
Unstable sort was added recently, and the code that is being modified is 3 years old. As quicksort doesn't allocate it will likely perform as well as, or better than linear search.
I didn't benchmark. Have a perf run.
Fix type inhabitedness check for arrays
Arrays of uninhabited types were considered to also be uninhabited if
their length had not been evaluated, causing unsoundness.
Fixes#47563.
r? @eddyb
Add CGU size heuristic for partitioning
This addresses the concern of #47316 by estimating CGU size based on
the size of its MIR. Looking at the size estimate differences for a
small selection of crates, this heuristic produces different orderings,
which should more accurately reflect optimisation time. (Fixes #47316.)
r? @michaelwoerister
When E0277's span points at a `for` loop, the actual issue is in the
element being iterated. Instead of pointing at the entire loop, point
only at the first line (when possible) so that the span ends in the
element for which E0277 was triggered.
Immovable generators
This adds support for immovable generators which allow you to borrow local values inside generator across suspension points. These are declared using a `static` keyword:
```rust
let mut generator = static || {
let local = &Vec::new();
yield;
local.push(0i8);
};
generator.resume();
// ERROR moving the generator after it has resumed would invalidate the interior reference
// drop(generator);
```
Region inference is no longer affected by the types stored in generators so the regions inside should be similar to other code (and unaffected by the presence of `yield` expressions). The borrow checker is extended to pick up the slack so interior references still result in errors for movable generators. This fixes#44197, #45259 and #45093.
This PR depends on [PR #44917 (immovable types)](https://github.com/rust-lang/rust/pull/44917), I suggest potential reviewers ignore the first commit as it adds immovable types.
This commit primarily adds the ability to control what kind of LTO happens when
rustc performs LTO, namely allowing values to be specified to the `-C lto`
option, such as `-C lto=thin` and `-C lto=fat`. (where "fat" is the previous
kind of LTO, throw everything in one giant module)
Along the way this also refactors a number of fields which store information
about whether LTO/ThinLTO are enabled to unify them all into one field through
which everything is dispatched, hopefully removing a number of special cases
throughout.
This is intended to help mitigate #47409 but will require a backport as well,
and this would unfortunately need to be an otherwise insta-stable option.
Create the concept of an `StructuredDiagnostic` that is self-contained
with enough knowledge of all variables to create a `DiagnosticBuilder`,
including different possible versions (one line output and expanded
explanations).
Change the --unpretty flag to -Z unpretty
First PR 😄 !
-Z unpretty no longer requires -Z unstable-options.
Also, I mildly changed the syntax of the flag to match the other -Z flags. All uses of the flag take the form `unpretty=something` where something can either `string` or `string=string` (see the help messages of the CLI).
Fix#47395
r? @nikomatsakis EDIT: apparently rust-highfive doesn't see edits...
Implement RFC 1946 - intra-rustdoc links
https://github.com/rust-lang/rfcs/pull/1946https://github.com/rust-lang/rust/issues/43466
Note for reviewers: The plain line counts are a little inflated because of how the markdown link parsing was done. [Read the file diff with "whitespace only" changes removed](https://github.com/rust-lang/rust/pull/47046/files?w=1) to get a better view of what actually changed there.
This pulls the name/path resolution mechanisms out of the compiler and runs it on the markdown in a crate's docs, so that links can be made to `SomeStruct` directly rather than finding the folder path to `struct.SomeStruct.html`. Check the `src/test/rustdoc/intra-paths.rs` test in this PR for a demo. The change was... a little invasive, but unlocks a really powerful mechanism for writing documentation that doesn't care about where an item was written to on the hard disk.
Items included:
- [x] Make work with the hoedown renderer
- [x] Handle relative paths
- [x] Parse out the "path ambiguities" qualifiers (`[crate foo]`, `[struct Foo]`, `[foo()]`, `[static FOO]`, `[foo!]`, etc)
- [x] Resolve foreign macros
- [x] Resolve local macros
- [x] Handle the use of inner/outer attributes giving different resolution scopes (handling for non-modules pushed to different PR)
Items not included:
- [ ] Make sure cross-crate inlining works (blocked on refactor described in https://github.com/rust-lang/rust/pull/47046#issuecomment-354824520)
- [ ] Implied Shortcut Reference Links (where just doing `[::std::iter::Iterator][]` without a reference anchor will resolve using the reference name rather than the link target) (requires modifying the markdown parser - blocked on Hoedown/Pulldown switch and https://github.com/google/pulldown-cmark/issues/121)
- [ ] Handle enum variants and UFCS methods (Enum variants link to the enum page, associated methods don't link at all)
- [ ] Emit more warnings/errors when things fail to resolve (linking to a value-namespaced item without a qualifier will emit an error, otherwise the link is just treated as a url, not a rust path)
- [ ] Give better spans for resolution errors (currently the span for the first doc comment is used)
- [ ] Check for inner doc comments on things that aren't modules
I'm making the PR, but it should be noted that most of the work was done by Misdreavus 😄
(Editor's note: This has become a lie, check that commit log, Manish did a ton of work after this PR was opened `>_>`)
renumber regions in generators
This fixes#47189, but I think we still have to double check various things around how to treat generators in MIR type check + borrow check (e.g., what borrows should be invalidated by a `Suspend`? What consistency properties should type check be enforcing anyway around the "interior" type?)
Also fixes#47587 thanks to @spastorino's commit.
r? @pnkfelix
Unstable sort was added recently, and the code that is being modified is 3 years old. As quicksort doesn't allocate it will likely perform as well as, or better than linear search.
Implement repr(transparent)
r? @eddyb for the functional changes. The bulk of the PR is error messages and docs, might be good to have a doc person look over those.
cc #43036
cc @nox
Custom error when moving arg outside of its closure
When given the following code:
```rust
fn give_any<F: for<'r> FnOnce(&'r ())>(f: F) {
f(&());
}
fn main() {
let mut x = None;
give_any(|y| x = Some(y));
}
```
provide a custom error:
```
error: borrowed data cannot be moved outside of its closure
--> file.rs:7:27
|
6 | let mut x = None;
| ----- borrowed data cannot be moved into here...
7 | give_any(|y| x = Some(y));
| --- ^ cannot be moved outside of its closure
| |
| ...because it cannot outlive this closure
```
instead of the generic lifetime error:
```
error[E0495]: cannot infer an appropriate lifetime due to conflicting requirements
--> file.rs:7:27
|
7 | give_any(|y| x = Some(y));
| ^
|
note: first, the lifetime cannot outlive the anonymous lifetime #2 defined on the body at 7:14...
--> file.rs:7:14
|
7 | give_any(|y| x = Some(y));
| ^^^^^^^^^^^^^^^
note: ...so that expression is assignable (expected &(), found &())
--> file.rs:7:27
|
7 | give_any(|y| x = Some(y));
| ^
note: but, the lifetime must be valid for the block suffix following statement 0 at 6:5...
--> file.rs:6:5
|
6 | / let mut x = None;
7 | | give_any(|y| x = Some(y));
8 | | }
| |_^
note: ...so that variable is valid at time of its declaration
--> file.rs:6:9
|
6 | let mut x = None;
| ^^^^^
```
Fix#45983.
