Use `preserve_mostcc` for `extern "rust-cold"`
As experimentation in #115242 has shown looks better than `coldcc`. Notably, clang exposes `preserve_most` (https://clang.llvm.org/docs/AttributeReference.html#preserve-most) but not `cold`, so this change should put us on a better-supported path.
And *don't* use a different convention for cold on Windows, because that actually ends up making things worse. (See comment in the code.)
cc tracking issue #97544
miri ABI compatibility check: accept u32 and i32
If only the sign differs, then surely these types are compatible. (We do still check that `arg_ext` is the same, just in case.)
Also I made it so that the ABI check must *imply* that size and alignment are the same, but it doesn't actively check that itself. With how crazy ABI constraints get, having equal size and align really shouldn't be used as a signal for anything I think...
Make RPITITs capture all in-scope lifetimes
Much like #114616, this implements the lang team decision from this T-lang meeting on [opaque captures strategy moving forward](https://hackmd.io/sFaSIMJOQcuwCdnUvCxtuQ?view). This will be RFC'd soon, but given that RPITITs are a nightly feature, this shouldn't necessarily be blocked on that.
We unconditionally capture all lifetimes in RPITITs -- impl is not as simple as #114616, since we still need to duplicate RPIT lifetimes to make sure we reify any late-bound lifetimes in scope.
Closes#112194
don't use SnapshotVec in Graph implementation, as it looks unused; use Vec instead
`Graph` don't use `SnapshotVec` methods, so use simple `Vec` instead?
More precisely detect cycle errors from type_of on opaque
Not sure if this still needs work. Just putting it up for initial impressions, since it seems that a few people are frustrated with the increased error verbosity due to #113320.
Essentially we introduce a new sub-query for `type_of` specifically for opaques which returns a value that is able to distinguish "has errors" from "due to cycle recovery".
Fixes#115188
r? `@oli-obk`
codegen_llvm/llvm_type: avoid matching on the Rust type
This `match` is highly suspicious. Looking at `scalar_llvm_type_at` I think it makes no difference. But if it were to make a difference that would be a huge problem, since it doesn't look through `repr(transparent)`!
Cc `@eddyb` `@bjorn3`
Avoid duplicate `large_assignments` lints
By checking for overlapping spans.
This PR does the "reduce noisiness" task in #83518.
r? `@oli-obk` who added E-mentor and E-help-wanted and wrote the initial code.
(The fix itself is in dc82736677. The two commits before that are just small refactorings.)
Rollup of 6 pull requests
Successful merges:
- #109660 (Document that SystemTime does not count leap seconds)
- #114238 (Fix implementation of `Duration::checked_div`)
- #114512 (std/tests: disable ancillary tests on freebsd since the feature itsel…)
- #114919 (style-guide: Add guidance for defining formatting for specific macros)
- #115278 (tell people what to do when removing an error code)
- #115280 (avoid triple-backtrace due to panic-during-cleanup)
r? `@ghost`
`@rustbot` modify labels: rollup
tell people what to do when removing an error code
Currently tidy and CI send developers on a wild goose chase:
- you edit the code
- CI/tidy tells you that an error code is gone, so you remove it from the list
- CI/tidy tells you that the markdown file is stale, so you remove that as well
- CI (but not tidy) tells you not to remove an error description and copy what E0001 does
Let's be nice to people and directly tell them what to do rather than making them follow misleading breadcrumbs.
r? ``@GuillaumeGomez``
Load include_bytes! directly into an Lrc
This PR deletes an innocent-looking `.into()` that was converting from a `Vec<u8>` to `Lrc<[u8]>`. This has significant runtime and memory overhead when using `include_bytes!` to pull in a large binary file.
Add a specialization for encoding byte arrays in rmeta
This specialization already exists for FileEncoder, but since EncodeContext is implemented by forwarding down to FileEncoder, using EncodeContext used to bypass the specialization.
Add an (perma-)unstable option to disable vtable vptr
This flag is intended for evaluation of trait upcasting space cost for embedded use cases.
Compared to the approach in #112355, this option provides a way to evaluate end-to-end cost of trait upcasting. Rationale: https://github.com/rust-lang/rust/issues/112355#issuecomment-1658207769
## How this flag should be used (after merge)
Build your project with and without `-Zno-trait-vptr` flag. If you are using cargo, set `RUSTFLAGS="-Zno-trait-vptr"` in the environment variable. You probably also want to use `-Zbuild-std` or the binary built may be broken. Save both binaries somewhere.
### Evaluate the space cost
The option has a direct and indirect impact on vtable space usage. Directly, it gets rid of the trait vptr entry needed to store a pointer to a vtable of a supertrait. (IMO) this is a small saving usually. The larger saving usually comes with the indirect saving by eliminating the vtable of the supertrait (and its parent).
Both impacts only affects vtables (notably the number of functions monomorphized should , however where vtable reside can depend on your relocation model. If the relocation model is static, then vtable is rodata (usually stored in Flash/ROM together with text in embedded scenario). If the binary is relocatable, however, the vtable will live in `.data` (more specifically, `.data.rel.ro`), and this will need to reside in RAM (which may be a more scarce resource in some cases), together with dynamic relocation info living in readonly segment.
For evaluation, you should run `size` on both binaries, with and without the flag. `size` would output three columns, `text`, `data`, `bss` and the sum `dec` (and it's hex version). As explained above, both `text` and `data` may change. `bss` shouldn't usually change. It'll be useful to see:
* Percentage change in text + data (indicating required flash/ROM size)
* Percentage change in data + bss (indicating required RAM size)
Move a local to the `#if` block where it is used
For other cases (LLVM < 17), this was complaining under `-Wall`:
```
warning: llvm-wrapper/PassWrapper.cpp: In function ‘void LLVMRustPrintTargetCPUs(LLVMTargetMachineRef, const char*)’:
warning: llvm-wrapper/PassWrapper.cpp:311:26: warning: unused variable ‘MCInfo’ [-Wunused-variable]
warning: 311 | const MCSubtargetInfo *MCInfo = Target->getMCSubtargetInfo();
warning: | ^~~~~~
```
This reverts commit 4410868798, reversing
changes made to 249595b752.
This causes linker failures with the binutils version used by
cross (#115239), as well as miscompilations when using the mold
linker.
As experimentation in 115242 has shown looks better than `coldcc`.
And *don't* use a different convention for cold on Windows, because that actually ends up making things worse.
cc tracking issue 97544
Point at type parameter that introduced unmet bound instead of full HIR node
```
error[E0277]: the size for values of type `[i32]` cannot be known at compilation time
--> $DIR/issue-87199.rs:18:15
|
LL | ref_arg::<[i32]>(&[5]);
| ^^^^^ doesn't have a size known at compile-time
```
instead of
```
error[E0277]: the size for values of type `[i32]` cannot be known at compilation time
--> $DIR/issue-87199.rs:18:22
|
LL | ref_arg::<[i32]>(&[5]);
| ---------------- ^^^^ doesn't have a size known at compile-time
| |
| required by a bound introduced by this call
```
------
```
error[E0277]: the trait bound `String: Copy` is not satisfied
--> $DIR/own-bound-span.rs:14:24
|
LL | let _: <S as D>::P<String>;
| ^^^^^^ the trait `Copy` is not implemented for `String`
|
note: required by a bound in `D::P`
--> $DIR/own-bound-span.rs:4:15
|
LL | type P<T: Copy>;
| ^^^^ required by this bound in `D::P`
```
instead of
```
error[E0277]: the trait bound `String: Copy` is not satisfied
--> $DIR/own-bound-span.rs:14:12
|
LL | let _: <S as D>::P<String>;
| ^^^^^^^^^^^^^^^^^^^ the trait `Copy` is not implemented for `String`
|
note: required by a bound in `D::P`
--> $DIR/own-bound-span.rs:4:15
|
LL | type P<T: Copy>;
| ^^^^ required by this bound in `D::P`
```
Fix#105306.
Remove lub_empty from lexical region resolve
As of my understanding this method made sense when we had `ReEmpty`.
Removed `lub_empty` and made the calling site code equivalent.
r? `@lcnr` `@compiler-errors`
