[MIR] Make scopes debuginfo-specific (visibility scopes).
Fixes#32949 by having MIR (visibility) scopes mimic the lexical structure.
Unlike #33235, this PR also removes all scopes without variable bindings.
Printing of scopes also changed, e.g. for:
```rust
fn foo(x: i32, y: i32) { let a = 0; let b = 0; let c = 0; }
```
Before my changes:
```rust
fn foo(arg0: i32, arg1: i32) -> () {
let var0: i32; // "x" in scope 1 at <anon>:1:8: 1:9
let var1: i32; // "y" in scope 1 at <anon>:1:16: 1:17
let var2: i32; // "a" in scope 3 at <anon>:1:30: 1:31
let var3: i32; // "b" in scope 6 at <anon>:1:41: 1:42
let var4: i32; // "c" in scope 9 at <anon>:1:52: 1:53
...
scope tree:
0 1 2 3 {
4 5
6 {
7 8
9 10 11
}
}
}
```
After my changes:
```rust
fn foo(arg0: i32, arg1: i32) -> () {
scope 1 {
let var0: i32; // "x" in scope 1 at <anon>:1:8: 1:9
let var1: i32; // "y" in scope 1 at <anon>:1:16: 1:17
scope 2 {
let var2: i32; // "a" in scope 2 at <anon>:1:30: 1:31
scope 3 {
let var3: i32; // "b" in scope 3 at <anon>:1:41: 1:42
scope 4 {
let var4: i32; // "c" in scope 4 at <anon>:1:52: 1:53
}
}
}
}
...
}
rustc: Try to contain prepends to PATH
This commit attempts to bring our prepends to PATH on Windows when loading
plugins because we've been seeing quite a few issues with failing to spawn a
process on Windows, the leading theory of which is that PATH is too large as a
result of this. Currently this is mostly a stab in the dark as it's not
confirmed to actually fix the problem, but it's probably not a bad change to
have anyway!
cc #33844Closes#17360
rustdoc: Fix generating redirect pages for statics and consts
These were missing from the cache for some reason meaning the redirect pages failed to render.
Remove the old FOLLOW checking (aka `check_matcher_old`).
It was supposed to be removed at the next release cycle but is still in the tree since like 6 months.
Potential breaking change, since some cases (such as #25658) will change from a warning to an error. But the warning stating that it will be a hard error in the next release has been there for 6 months now.
I think it's safe to break this code. ^_^
trans: always use a memcpy for ABI argument/return casts.
When storing incoming arguments or values returned by call/invoke, always do a `memcpy` from a temporary of the cast type, if there is an ABI cast.
While Clang has gotten smarter ([store](https://godbolt.org/g/EphFuK) vs [memcpy](https://godbolt.org/g/5dikH9)), a `memcpy` will always work.
This is what @dotdash has wanted to do all along, and it fixes#32049.
This was using an invalid iterator so is likely to end with buggy
behaviour.
It also doesn't even benefit many type in std including Vec so removing it
shouldn't cause any problems.
Have included an example of a Cargo.toml file containing the libc dependency.
The file has been reformatted to use sections. The note on the default features warning is part of the _Using libc_ section but is in bold.
Remove old -Z options that do nothing
Technically, this is a [breaking-change], but I'm not sure what the policy for -Z flags is (especially unused ones).
Update rc.rs
The original description suggests that the original `Rc<T>` itself is downgraded, which doesn't seem to be what the code does. At the same time, `Rc` is one of those types that can do weird things with only a shared reference, so I thought it would be good to be clear.
Minor changes to variable bindings chapter
* In "*... name as another binding, that's currently in scope, will ...*", *"
that's currently in scope"* is not a parenthetical element, and the commas
can be omitted.
* Other minor changes.
add documentation on howto build just rustc without libstd to the build system
I searched for days until I found this, maybe this helps other poor souls 😂
for reference #33990
[MIR] Fix MIR trans edge cases that showed up on crater.
These fixes cover all of the [regressions found by crater](https://gist.github.com/nikomatsakis/88ce89ed06ef7f7f19bfd1e221d7f7ec) (for #34096).
Two of them were `Pair` edge cases (ZSTs and constants) causing LLVM assertions, the other one was causing stack overflows in debug scripts compiled in debug mode, due to the `fn_ret_cast` `alloca` ending up in a loop.
(Includes a regression test, which needed to go into `compile-fail/`
due to weaknesses when combining `#[deny(warnings)]` with
`tcx.sess.span_warn(..)`)
(updated with review feedback from arielb1.)
rustc: add ReErased to be used by trait selection, MIR and trans.
`ReErased` replaces `ReStatic` (i.e. `'static`) for erasing regions.
Using a distinct lifetime helps prevent accidental mix-ups between the two.
It also allows cleaner type printing (see test changes), including in symbol names:
```rust
str..pattern..CharSearcher$LT$$u27$static$GT$::drop.30560::h840c2f2afc03bbea // before
str..pattern..CharSearcher::drop.30561::h6bd31d2af614377a // after
```
Not that we should be producing symbols this way, but it's still better.
* In "... name as another binding, that's currently in scope, will ...", ",
that's currently in scope, " is not a parenthetical element, and the commas
can be omitted.
* Other minor changes.
The book's "Error handling with Box<Error>" section talks about Box<Error>.
In the actual example Box<Error + Send + Sync> is used instead so that the
corresponding From impls could be used to convert a plain string to an error
type. Rust 1.7 added support for conversion from &str/String to
Box<Error>, so this gotcha and later references to it can now be removed.
