When the panic handler is run, the existing Handler may be in a weird
state if it was responsible for triggering the panic. By using a freshly
created Handler, we avoid trying to re-entrantly lock a HandlerInner,
which was causing a double panic on ICEs.
Refactor librustc_errors::Handler API
This should be reviewed by-commit.
The last commit moves all fields into an inner struct behind a single lock; this is done to prevent possible deadlocks in a multi-threaded compiler, as well as inconsistent state observation.
Use `panic::set_hook` to print the ICE message
This allows custom frontends and backends to override the hook with their own, for example to point people to a different issue tracker.
ICE messages are printed in a slightly different order now. Nightly prints:
```
thread 'rustc' panicked at 'called `Option::unwrap()` on a `None` value', src/libcore/option.rs:347:21
note: Run with `RUST_BACKTRACE=1` environment variable to display a backtrace.
error: aborting due to 2 previous errors
Some errors have detailed explanations: E0277, E0658.
For more information about an error, try `rustc --explain E0277`.
error: internal compiler error: unexpected panic
note: the compiler unexpectedly panicked. this is a bug.
note: we would appreciate a bug report: https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md#bug-reports
note: rustc 1.36.0-nightly (08bfe1612 2019-05-02) running on x86_64-unknown-linux-gnu
```
After this PR, rustc prints:
```
thread 'rustc' panicked at 'called `Option::unwrap()` on a `None` value', src/libcore/option.rs:347:21
note: Run with `RUST_BACKTRACE=1` environment variable to display a backtrace.
error: internal compiler error: unexpected panic
note: the compiler unexpectedly panicked. this is a bug.
note: we would appreciate a bug report: https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md#bug-reports
note: rustc 1.36.0-dev running on x86_64-unknown-linux-gnu
error: aborting due to 2 previous errors
Some errors have detailed explanations: E0277, E0658.
For more information about an error, try `rustc --explain E0277`.
```
rustc: implement argsfiles for command line
Many tools, such as gcc and gnu-ld, support "args files" - that is, being able to specify @file on the command line. This causes `file` to be opened and parsed for command line options. They're separated with whitespace; whitespace can be quoted with double or single quotes, and everything can be \\-escaped. Args files may recursively include other args files via `@file2`.
See https://sourceware.org/binutils/docs/ld/Options.html#Options for the documentation of gnu-ld's @file parameters.
This is useful for very large command lines, or when command lines are being generated into files by other tooling.
This will make @path work with miri and other non-standard entrypoints.
Also since this simplifies librustc_driver::args, move it into a simple source file. Also
remove the tests since they're doing nothing more than checking `str::lines` has the right
behaviour.
This makes `rustc` support `@path` arguments on the command line. The `path` is opened and the file is interpreted
as new command line options which are logically inserted at that point in the command-line. The options in the file
are one per line. The file is UTF-8 encoded, and may have either Unix or Windows line endings.
It does not support recursive use of `@path`.
This is useful for very large command lines, or when command-lines are being generated into files by other tooling.
This enforces that eof() must be called to get the String out, and
generally is better from an API perspective. No users of pretty printing
pre-allocate the buffer.
Exit arm scopes
Due to a bug in the HIR CFG construction, borrows for arm scopes were incorrectly leaking into other arms.
This PR also includes some drive-by improvements to `-Zunpretty=hir,identified` that would have been helpful while investigating this.
Closes#62107
