[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.
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.
