This commit removes all in-tree support for generating backtraces in
favor of depending on the `backtrace` crate on crates.io. This resolves
a very longstanding piece of duplication where the standard library has
long contained the ability to generate a backtrace on panics, but the
code was later extracted and duplicated on crates.io with the
`backtrace` crate. Since that fork each implementation has seen various
improvements one way or another, but typically `backtrace`-the-crate has
lagged behind libstd in one way or another.
The goal here is to remove this duplication of a fairly critical piece
of code and ensure that there's only one source of truth for generating
backtraces between the standard library and the crate on crates.io.
Recently I've been working to bring the `backtrace` crate on crates.io
up to speed with the support in the standard library which includes:
* Support for `StackWalkEx` on MSVC to recover inline frames with
debuginfo.
* Using `libbacktrace` by default on MinGW targets.
* Supporting `libbacktrace` on OSX as an option.
* Ensuring all the requisite support in `backtrace`-the-crate compiles
with `#![no_std]`.
* Updating the `libbacktrace` implementation in `backtrace`-the-crate to
initialize the global state with the correct filename where necessary.
After reviewing the code in libstd the `backtrace` crate should be at
exact feature parity with libstd today. The backtraces generated should
have the same symbols and same number of frames in general, and there's
not known divergence from libstd currently.
Note that one major difference between libstd's backtrace support and
the `backtrace` crate is that on OSX the crates.io crate enables the
`coresymbolication` feature by default. This feature, however, uses
private internal APIs that aren't published for OSX. While they provide
more accurate backtraces this isn't appropriate for libstd distributed
as a binary, so libstd's dependency on the `backtrace` crate explicitly
disables this feature and forces OSX to use `libbacktrace` as a
symbolication strategy.
The long-term goal of this refactoring is to eventually move us towards
a world where we can drop `libbacktrace` entirely and simply use Gimli
and the surrounding crates for backtrace support. That's still aways off
but hopefully will much more easily enabled by having the source of
truth for backtraces live in crates.io!
Procedurally if we go forward with this I'd like to transfer the
`backtrace-rs` crate to the rust-lang GitHub organization as well, but I
figured I'd hold off on that until we get closer to merging.
Rollup of 13 pull requests
Successful merges:
- #61026 (Tweak macro parse errors when reaching EOF during macro call parse)
- #61095 (Update cargo)
- #61096 (tidy: don't short-circuit on license error)
- #61107 (Fix a couple docs typos)
- #61110 (Revert edition-guide toolstate override)
- #61111 (Fixed type-alias-bounds lint doc)
- #61113 (Deprecate `FnBox`. `Box<dyn FnOnce()>` can be called directly, since 1.35)
- #61116 (Remove the incorrect warning from README.md)
- #61118 (Dont ICE on an attempt to use GAT without feature gate)
- #61121 (improve debug-printing of scalars)
- #61125 (Updated my mailmap entry)
- #61134 (Annotate each `reverse_bits` with `#[must_use]`)
- #61138 (Move async/await tests to their own folder)
Failed merges:
r? @ghost
Move async/await tests to their own folder
This moves run-pass and ui async/await tests to their own folder `src/test/ui/async-await` and organises some into subfolders. (It does not move rustdoc tests for async/await.)
I also did some drive-by cleaning up of issues/error code tests into their own folders (which already existed). These are in separate commits, so easy to separate out if that's more desirable.
r? @cramertj
tidy: don't short-circuit on license error
If there is more than one license error, tidy would only print the first
error. This changes it so that all license errors are printed.
Tweak macro parse errors when reaching EOF during macro call parse
Add detail on origin of current parser when reaching EOF, stop saying "found `<eof>`" and point at the end of macro calls.
Fix#27569.
Make place projections concrete.
**I'm not sure if we want this. I'm raising the PR for discussion**
Whilst doing some work on our Rust fork, I noticed the following:
Once upon a time (commit 9bd35c07c2) there were two kinds of
projection: one for places, and one for constants. It therefore made
sense to share the `Projection` struct for both. Although the different
use-cases used different concrete types, sharing was made possible by
type-parameterisation of `Projection`.
Since then, however, the usage of projections in constants has
disappeared, meaning that (forgetting lifetimes for a moment) the
parameterised type is only every instantiated under one guise. So it may
as well be a concrete type. Right?
What do people think? This is entirely untested, although it does check.
If we *don't* want this, then we should at least update the incorrect comment against `Projection`.
Thanks
Add Azure Pipelines configuration
Huge thanks to ＠johnterickson and ＠willsmythe for writing the initial config! ❤️
I applied some changes to the initial config and disabled most of the builders since we're not going to run all of them during the initial step for the evaluation.
[More details about our plans for the Azure Pipelines evaluation.](https://internals.rust-lang.org/t/update-on-the-ci-investigation/10056)
r? ＠alexcrichton ＠kennytm
cc ＠rust-lang/infra ＠ethomson ＠rylev
- Add detail on origin of current parser when reaching EOF and stop
saying "found <eof>" and point at the end of macro calls
- Handle empty `cfg_attr` attribute
- Reword empty `derive` attribute error
Once upon a time (commit 9bd35c07c2) there were two kinds of
projection: one for places, and one for constants. It therefore made
sense to share the `Projection` struct for both. Although the different
use-cases used different concrete types, sharing was made possible by
type-parameterisation of `Projection`.
Since then, however, the usage of projections in constants has
disappeared, meaning that (forgetting lifetimes for a moment) the
parameterised type is only every instantiated under one guise. So it may
as well be a concrete type.
