When the compiler driver panics it attempts to show a hint about using
`RUST_BACKTRACE`. However, the logic is currently reversed to the hint
is only shown if `RUST_BACKTRACE` is *already* set:
```shell
> RUST_BACKTRACE=1 rustc /dev/null --crate-type proc-macro
error: internal compiler error: unexpected panic
...
note: run with `RUST_BACKTRACE=1` for a backtrace
thread 'rustc' panicked at 'attempt to subtract with overflow', librustc_errors/emitter.rs:287:49
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
> RUST_BACKTRACE=0 rustc /dev/null --crate-type proc-macro
error: internal compiler error: unexpected panic
...
thread 'rustc' panicked at 'attempt to subtract with overflow', librustc_errors/emitter.rs:287:49
note: Run with `RUST_BACKTRACE=1` for a backtrace.
```
As the `panic` itself already has a working `RUST_BACKTRACE` hint just
remove the broken duplicate hint entirely.
Change the --unpretty flag to -Z unpretty
First PR 😄 !
-Z unpretty no longer requires -Z unstable-options.
Also, I mildly changed the syntax of the flag to match the other -Z flags. All uses of the flag take the form `unpretty=something` where something can either `string` or `string=string` (see the help messages of the CLI).
Fix#47395
r? @nikomatsakis EDIT: apparently rust-highfive doesn't see edits...
-Z unpretty no longer requires -Z unstable-options. Also, I mildly
changed the syntax of the flag to match the other -Z flags. All uses of
the flag take the form `unpretty=something` where something can either
`string` or `string=string` (see the help messages of the CLI).
rustc: Tweak `#[target_feature]` syntax
This is an implementation of the `#[target_feature]` syntax-related changes of
[RFC 2045][rfc]. Notably two changes have been implemented:
* The new syntax is `#[target_feature(enable = "..")]` instead of
`#[target_feature = "+.."]`. The `enable` key is necessary instead of the `+`
to indicate that a feature is being enabled, and a sub-list is used for
possible expansion in the future. Additionally within this syntax the feature
names being enabled are now whitelisted against a known set of target feature
names that we know about.
* The `#[target_feature]` attribute can only be applied to unsafe functions. It
was decided in the RFC that invoking an instruction possibly not defined for
the current processor is undefined behavior, so to enable this feature for now
it requires an `unsafe` intervention.
[rfc]: https://github.com/rust-lang/rfcs/blob/master/text/2045-target-feature.md
No longer parse it.
Remove AutoTrait variant from AST and HIR.
Remove backwards compatibility lint.
Remove coherence checks, they make no sense for the new syntax.
Remove from rustdoc.
Add -Ztime-passes line for dep-graph loading.
We measure how much time the background thread spends on loading the dep-graph but not how long the main thread is blocked while the background thread is still working. Let's change that!
Do not emit type errors on recovered blocks
When a parse error occurs on a block, the parser will recover and create
a block with the statements collected until that point. Now a flag
stating that a recovery has been performed in this block is propagated
so that the type checker knows that the type of the block (which will be
identified as `()`) shouldn't be checked against the expectation to
reduce the amount of irrelevant diagnostic errors shown to the user.
Fix#44579.
When a parse error occurs on a block, the parser will recover and create
a block with the statements collected until that point. Now a flag
stating that a recovery has been performed in this block is propagated
so that the type checker knows that the type of the block (which will be
identified as `()`) shouldn't be checked against the expectation to
reduce the amount of irrelevant diagnostic errors shown to the user.
Prevent rustc overwriting input files
If rustc is invoked on a file that would be overwritten by the
compilation, the compilation now fails, to avoid accidental loss. This
resolves#13019. Kudos to @estebank, whose patch I finished off.
Loading the dependency graph in the background
Patch is a bit longer than I expected, due to the fact that most of this code relies upon a `Session` value, which is not `Sync`.
Help Cargo tolerate RUSTFLAGS="--print=native-static-libs"
Alternative to https://github.com/rust-lang/cargo/pull/4807
Having this "error" message was a mistake, as it's firing at exactly wrong time when Cargo is trying to read the output of other print commands.
[MIR-borrowck] Two phase borrows
This adds limited support for two-phase borrows as described in
http://smallcultfollowing.com/babysteps/blog/2017/03/01/nested-method-calls-via-two-phase-borrowing/
The support is off by default; you opt into it via the flag `-Z two-phase-borrows`
I have written "*limited* support" above because there are simple variants of the simple `v.push(v.len())` example that one would think should work but currently do not, such as the one documented in the test compile-fail/borrowck/two-phase-reservation-sharing-interference-2.rs
(To be clear, that test is not describing something that is unsound. It is just providing an explicit example of a limitation in the implementation given in this PR. I have ideas on how to fix, but I want to land the work that is in this PR first, so that I can stop repeatedly rebasing this branch.)
Having the HIR local id is useful for cases like understanding the
ReScope identifiers, which are now derived from the HIR local id, and
thus one can map an ReScope back to the HIR node, once one knows what
those local ids are.
Now that we made `resolve_lifetimes` into a query, elision errors no
longer abort compilation, which affects some tests.
Also, remove `dep_graph_crosscontaminate_tables` -- there is no a path in
the dep-graph, though red-green handles it. The same scenario
is (correctly) tested by issue-42602.rs in any case.
