On `x86_64-pc-windows-msvc`, we often get backtraces which look like
this:
```
10: 0x7ff77e0e9be5 - std::panicking::rust_panic_with_hook
11: 0x7ff77e0e11b4 - std::sys_common::backtrace::__rust_begin_short_backtrace::h5769736bdb11136c
12: 0x7ff77e0e116f - std::sys_common::backtrace::__rust_end_short_backtrace::h61c7ecb1b55338ae
13: 0x7ff77e0f89dd - std::panicking::begin_panic::h8e60ef9f82a41805
14: 0x7ff77e0e108c - d
15: 0x7ff77e0e1069 - c
16: 0x7ff77e0e1059 - b
17: 0x7ff77e0e1049 - a
18: 0x7ff77e0e1039 - core::ptr::drop_in_place<std::rt::lang_start<()>::{{closure}}>::h1bfcd14d5e15ba81
19: 0x7ff77e0e1186 - std::sys_common::backtrace::__rust_begin_short_backtrace::h5769736bdb11136c
20: 0x7ff77e0e100c - std::rt::lang_start::{{closure}}::ha054184bbf9921e3
```
Notice that `__rust_begin_short_backtrace` appears on frame 11 before
`__rust_end_short_backtrace` on frame 12. This is because in typical
release binaries without debug symbols, dbghelp.dll, which we use to walk
and symbolize the stack, does not know where CGU internal functions
start or end and so the closure invoked by `__rust_end_short_backtrace`
is incorrectly described as `__rust_begin_short_backtrace` because it
happens to be near that symbol.
While that can obviously change, this has been happening quite
consistently since #75048. Since this is a very small change to the std
and the change makes sense by itself, I think this is worth doing.
This doesn't completely resolve the situation for release binaries on
Windows, since without debug symbols, the stack printed can still show
incorrect symbol names (this is why the test uses `#[no_mangle]`) but it
does slightly improve the situation in that you see the same backtrace
you would see with `RUST_BACKTRACE=full` or in a debugger (without the
uninteresting bits at the top and bottom).
Add #[track_caller] for some function in core::mem.
These functions can panic for some types. This makes the panic point to the code that calls e.g. mem::uninitialized(), instead of inside the definition of mem::uninitialized.
Make const panic!("..") work in Rust 2021.
During const eval, this replaces calls to core::panicking::panic_fmt and std::panicking::being_panic_fmt with a call to a new const fn: core::panicking::const_panic_fmt. That function uses fmt::Arguments::as_str() to get the str and calls panic_str with that instead.
panic!() invocations with formatting arguments are still not accepted, as the creation of such a fmt::Arguments cannot be done in constant functions right now.
r? `@RalfJung`
Integrate context into the memorial to Anna
This came up after I reviewed https://github.com/rust-lang/rust/pull/87298, but I didn't propose this in time before that PR was merged.
If y'all feel this is too much churn on the file, no worries, feel free to close, but I felt this was a more fitting integration of the memorial into the test suite.
CC ``@boringcactus.``
Add support for tuple struct field documentation
Fixes #42615.
This is #80320 updated to new codebase and with added tests.
Part of https://github.com/rust-lang/rust/issues/83255.
cc ```@camelid``` (since you were involved on the original PR).
r? ```@jyn514```
These functions can panic for some types. This makes the panic point to
the code that calls e.g. mem::uninitialized(), instead of inside the
definition of mem::uninitialized.
Support -Z unpretty=thir-tree again
Currently `-Z unpretty=thir-tree` is broken after some THIR refactorings. This re-implements it, making it easier to debug THIR-related issues.
We have to do analyzes before getting the THIR, since trying to create THIR from invalid HIR can ICE. But doing those analyzes requires the THIR to be built and stolen. We work around this by creating a separate query to construct the THIR tree string representation.
Closes https://github.com/rust-lang/project-thir-unsafeck/issues/8, fixes#85552.
Implement RFC 3107: `#[derive(Default)]` on enums with a `#[default]` attribute
This PR implements RFC 3107, which permits `#[derive(Default)]` on enums where a unit variant has a `#[default]` attribute. See comments for current status.
Add flag to configure `large_assignments` lint
The `large_assignments` lints detects moves over specified limit. The
limit is configured through `move_size_limit = "N"` attribute placed at
the root of a crate. When attribute is absent, the lint is disabled.
Make it possible to enable the lint without making any changes to the
source code, through a new flag `-Zmove-size-limit=N`. For example, to
detect moves exceeding 1023 bytes in a cargo crate, including all
dependencies one could use:
```
$ env RUSTFLAGS=-Zmove-size-limit=1024 cargo build -vv
```
Lint tracking issue #83518.
Remove unstable `--pretty` flag
It doesn't do anything `--unpretty` doesn't, and due to a bug, also
didn't show up in `--help`. I don't think there's any reason to keep it
around, I haven't seen anyone using it.
Closes https://github.com/rust-lang/rust/issues/36473.
Rollup of 8 pull requests
Successful merges:
- #87436 (Suggest `;` on parse error where applicable)
- #87444 (Flatten nested `format!` calls)
- #87447 (Miri: santiy check that null pointer can never have an AllocId)
- #87457 (freebsd remove compiler workaround.)
- #87458 (Fix help message for modification to &T created by &{t})
- #87464 (Remove unnecessary `structhead` parameter from `render_union`)
- #87473 (Notify the Rust 2021 edition working group in zulip of edition bugs)
- #87474 (Add missing whitespace after attribute in HTML template)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Fix help message for modification to &T created by &{t}
Previous:
```rust
error[E0594]: cannot assign to `*x` which is behind a `&` reference
--> src/main.rs:3:5
|
2 | let x: &usize = &mut{0};
| ------- help: consider changing this to be a mutable reference: `&mut mut{0}`
3 | *x = 1;
| ^^^^^^ `x` is a `&` reference, so the data it refers to cannot be written
```
