This approach is, roughly, based on how Discourse does it.
It came up while discussing some other possible sidebar changes,
as a design that made rapid scanning easier while avoiding the
inherent trade-offs in summarizing.
Added "copy" to Debug fmt for copy operands
In MIR's debug mode (--emit mir) the printing for Operands is slightly inconsistent.
The RValues - values on the right side of an Assign - are usually printed with their Operand when they are Places.
Example:
_2 = move _3
But for arguments, the operand is omitted.
_2 = _1
I propose a change be made, to display the place with the operand.
_2 = copy _1
Move and copy have different semantics, meaning this difference is important and helpful to the user. It also adds consistency to the pretty printing.
-- EDIT --
Consider this example Rust program and its MIR output with the **updated pretty printer.**
This was generated with the arguments --emit mir --crate-type lib -Zmir-opt-level=0 (Otherwise, it's optimised away since it's a junk program).
```rust
fn main(foo: i32) {
let v = 10;
if v == 20 {
foo;
}
else {
v;
}
}
```
```MIR
// WARNING: This output format is intended for human consumers only
// and is subject to change without notice. Knock yourself out.
fn main(_1: i32) -> () {
debug foo => _1;
let mut _0: ();
let _2: i32;
let mut _3: bool;
let mut _4: i32;
let _5: i32;
let _6: i32;
scope 1 {
debug v => _2;
}
bb0: {
StorageLive(_2);
_2 = const 10_i32;
StorageLive(_3);
StorageLive(_4);
_4 = copy _2;
_3 = Eq(move _4, const 20_i32);
switchInt(move _3) -> [0: bb2, otherwise: bb1];
}
bb1: {
StorageDead(_4);
StorageLive(_5);
_5 = copy _1;
StorageDead(_5);
_0 = const ();
goto -> bb3;
}
bb2: {
StorageDead(_4);
StorageLive(_6);
_6 = copy _2;
StorageDead(_6);
_0 = const ();
goto -> bb3;
}
bb3: {
StorageDead(_3);
StorageDead(_2);
return;
}
}
```
In this example program, we can see that when we move a place, it is preceded by "move". e.g. ``` _3 = Eq(move _4, const 20_i32);```. However, when we copy a place such as ```_5 = _1;```, it is not preceded by the operand in the original printout. I propose to change the print to include the copy ```_5 = copy _1``` as in this example.
Regarding the arguments part. When I originally submitted this PR, I was under the impression this only affected the print for arguments to a function, but actually, it affects anything that uses a copy. This is preferable anyway with regard to consistency. The PR is about making ```copy``` explicit.
Trigger [`string_slice`] if expression is reference to `&str`
Close#12708
changelog: [`string_slice`]: trigger lint if expression is reference to `&str`
fix false positive in explicit_iter_loop with msrv
close#13184
This PR fix false positive in explicit_iter_loop when msrv < 1.80
changelog: fix false positive in explicit_iter_loop when msrv < 1.80
Prevent double panic in query system, improve diagnostics
I stumbled upon a double-panic in the query system while working on something else (#129102), which hid the real error cause for what I was debugging. This PR remedies that, so unwinding should be able to present more errors. It shouldn't really be relevant for code that doesn't ICE.
safe transmute: check lifetimes
Modifies `BikeshedIntrinsicFrom` to forbid lifetime extensions on references. This static check can be opted out of with the `Assume::lifetimes` flag.
Fixes#129097
Tracking Issue: https://github.com/rust-lang/rust/issues/99571
r? `@compiler-errors`
Before the workspace split, the library was covered by the weekly `cargo
update` cron job. Now that the library has its own workspace, it doesn't
get these updates.
Add `library/Cargo.toml` to the job so updates happen again.
Delete debuginfo test suite infra for gdb without Rust support and lldb with Rust support
Implements https://github.com/rust-lang/rust/issues/128953
I also deleted all the `min-lldb-version: 310` comments, because the oldest compatible distro I can find is Ubuntu 16.04 which ships lldb 3.8, though of course the package that the Ubuntu maintainers put together for that is broken.
Rocky Linux 8 amusingly ships lldb 17, even though it has a similar glibc and kernel version.
This PR is multiple highly mechanical changes. Some of the commits were created by just running `sed`. You may find it easier to review each commit separately.
Switch to using the v2 resolver in most workspaces
Pinning the resolver to v1 was done in 5abff3753a ("Explicit set workspace.resolver ...") in order to suppress warnings. Since there is no specific reason not to use the new resolver and since it fixes issues, change to `resolver = "2"` everywhere except library.
Rollup of 7 pull requests
Successful merges:
- #127679 (Stabilize `raw_ref_op` (RFC 2582))
- #128084 (Suggest adding Result return type for associated method in E0277.)
- #128628 (When deduplicating unreachable blocks, erase the source information.)
- #128902 (doc: std::env::var: Returns None for names with '=' or NUL byte)
- #129048 (Update `crosstool-ng` for loongarch64)
- #129116 (Include a copy of `compiler-rt` source in the `download-ci-llvm` tarball)
- #129208 (Fix order of normalization and recursion in const folding.)
r? `@ghost`
`@rustbot` modify labels: rollup
Fix order of normalization and recursion in const folding.
Fixes#126831.
Without this patch, type normalization is not always idempotent, which leads to all sorts of bugs in places that assume that normalizing a normalized type does nothing.
Tracking issue: https://github.com/rust-lang/rust/issues/95174
r? BoxyUwU
Include a copy of `compiler-rt` source in the `download-ci-llvm` tarball
This will make it possible to experiment with allowing `download-ci-llvm` builds to build `library/profiler_builtins`, without needing to check out the `src/llvm-project` submodule.
By itself, this PR just adds the files to the tarball, but doesn't actually do anything with them. The idea is that once this is merged, it will then be much easier to proceed with work on the necessary bootstrap changes (using the real downloaded tarball), without having to rig up weird hacks to simulate downloading a modified tarball.
---
Adding these files to the compressed tarballs appears to increase its size by a negligible amount (<1 MB out of 400/800+ MB).
The uncompressed size is about 14 MB (out of 2+ GB for the whole tarball).
(The excluded test files would have been another 35 MB.)
Update `crosstool-ng` for loongarch64
The current cross-compilation toolchain for the LoongArch64 target consists of GCC 13.2.0, Binutils 2.40, and Glibc 2.36. However, Binutils 2.40 has known issues that in broken binaries without any error reports:
- https://github.com/rust-lang/rust/issues/121289
- https://github.com/cross-rs/cross/issues/1538
This patch upgrades the cross-compilation toolchain for the LoongArch64 target to resolve these issues.
- GCC: 13.2.0 -> 14.2.0
- Binutils: 2.40 -> 2.42
The new binaries remain compatible with the existing GCC 13.2.0/Glibc 2.36 distribution, and no issues have been identified.
try-job: dist-loongarch64-linux
doc: std::env::var: Returns None for names with '=' or NUL byte
The documentation incorrectly stated that std::env::var could return an error for variable names containing '=' or the NUL byte. Copy the correct documentation from var_os.
var_os was fixed in Commit 8a7a665, Pull Request #109894, which closed Issue #109893.
This documentation was incorrectly added in commit f2c0f292, which replaced a panic in var_os by returning None, but documented the change as "May error if ...".
Reference the specific error values and link to them.
When deduplicating unreachable blocks, erase the source information.
After deduplication the block conceptually belongs to multiple locations in the source. Although these blocks are unreachable, in #123341 we did come across a real side effect, an unreachable block that survives into the compiled code can cause a debugger to set a breakpoint on the wrong instruction. Erasing the source information ensures that a debugger will never be misled into thinking that the unreachable block is worth setting a breakpoint on, especially after #128627.
Technically we don't need to erase the source information if all the deduplicated blocks have identical source information, but tracking that seems like more effort than it's worth.
I'll let njn redirect this one too. r? `@nnethercote`
Suggest adding Result return type for associated method in E0277.
Recommit #126515 because I messed up during rebase,
Suggest adding Result return type for associated method in E0277.
For following:
```rust
struct A;
impl A {
fn test4(&self) {
let mut _file = File::create("foo.txt")?;
//~^ ERROR the `?` operator can only be used in a method
}
```
Suggest:
```rust
impl A {
fn test4(&self) -> Result<(), Box<dyn std::error::Error>> {
let mut _file = File::create("foo.txt")?;
//~^ ERROR the `?` operator can only be used in a method
Ok(())
}
}
```
For #125997
r? `@cjgillot`
