Migrate a slew of metadata methods to queries
This PR intends to make more progress on #41417, knocking off some low-hanging fruit.
Closes#44190
cc #44137
pprust: fix parenthesization of exprs
The pretty printer in `syntax::print::pprust` currently relies on the presence of `ExprKind::Paren` hints in order to correctly parenthesize expressions in its output. If `Paren` nodes are missing, it sometimes produces wrong output, such as printing `1 - (2 - 3)` as `1 - 2 - 3`. This PR fixes `pprust` to correctly print expressions regardless of the presence or absence of `Paren` nodes. This should make `pprust` easier to use with programmatically constructed ASTs.
A few notes:
* I added a function for assigning precedence values to exprs in `syntax::util::parser`, since there is already code there for assigning precedence values to binops. Let me know if I should move this somewhere more `pprust`-specific.
* I also moved the `contains_exterior_struct_lit` function from `rustc_lint::unused::UnusedParens` into `syntax::util::parser`, since it's needed for determining the correct parenthesization of `if`/`while` conditional expressions.
* I couldn't find a good way to compare two exprs for equivalence while ignoring semantically-irrelevant details like spans. So the test for the new behavior relies on a slight hack: it adds `Paren` nodes everywhere, so that the pretty-printed version exactly reflects the structure of the AST, and then compares the printed strings. This works, but let me know if there's a better way.
Travis recently pushed an update to the Linux environments, namely the kernels
that we're running on. This in turn caused some of the sanitizer tests we run to
fail. We also apparently weren't the first to hit these failures! Detailed in
google/sanitizers#837 these tests were failing due to a specific commit in the
kernel which has since been backed out, but for now work around the buggy kernel
that's deployed on Travis and eventually we should be able to remove these
flags.
travis: Downgrade to previous images temporarily
Travis is in the process of [rolling out an update][update] but looks like our
tests are breaking, let's temporarily roll back to get the queue moving again.
[update]: https://blog.travis-ci.com/2017-08-29-trusty-image-updates
This commit moves the `crates` method to a query and then migrates all callers
to use a query instead of the now-renamed `crates_untracked` method where
possible.
Closes#41417
Debugflag: -Z emit-end-regions
Skip EndRegion emission by default. Use `-Z emit-end-regions` to reenable it.
The main intent is to fix cases where `EndRegion` emission is believed to be causing excess peak memory pressure.
It may also be a welcome change to people inspecting the MIR output who find the EndRegions to be a distraction.
(In later follow-up PR's I will put in safe-guards against using the current mir-borrowck without enabling `EndRegion` emission. But I wanted this PR to be minimal, in part because we may wish to backport it to the beta channel if we find that it reduces peak memory usage significantly.)
Fixes#38384
Most of the Rust community uses 4 spaces for indentation,
but there are also tab users of Rust (including myself!).
This patch fixes a bug in error printing which mispositions
error indicators when near code with tabs.
The code attempted to fix the issue by replacing spaces
with tabs, but it sadly wasn't enough, as sometimes
you may not print spaces but _ or ^ instead.
This patch employs the reverse strategy: it replaces each
tab with a space, so that the number of _ and ^ and spaces
in error indicators below the code snippet line up
perfectly.
In a study [1] preceeding this patch, we could see that
this strategy is also chosen by gcc version 6.3.0.
Its not perfect, as the output is not beautiful, but its
the easiest to implement. If anyone wants to improve on
this, be my guest! This patch is meant as improvement of
the status quo, not as perfect end status. It fixes the
actual issue of mispositioning error indicators.
[1]: https://github.com/rust-lang/rust/issues/38384#issuecomment-326813710
Make the LocalKey facade of thread_local! inlineable cross-crate.
Fixes (almost*) #25088 by changing the `LocalKey` `static` `thread_local!` generates to a `const`.
This can be done because a `LocalKey` value holds no actual TLS data, only function pointers to get at said data, and it could even be made `Copy` without any negative consequences.
The recent stabilization of rvalue promotion to `'static` allows doing this without changing the API.
r? @alexcrichton
*almost because we can't yet inline `__getit` because it breaks on MSVC, see https://github.com/rust-lang/rust/pull/43931#issuecomment-323534214
rustc: Attempt to handle super long linker invocations
This commit adds logic to the compiler to attempt to handle super long linker
invocations by falling back to the `@`-file syntax if the invoked command is too
large. Each OS has a limit on how many arguments and how large the arguments can
be when spawning a new process, and linkers tend to be one of those programs
that can hit the limit!
The logic implemented here is to unconditionally attempt to spawn a linker and
then if it fails to spawn with an error from the OS that indicates the command
line is too big we attempt a fallback. The fallback is roughly the same for all
linkers where an argument pointing to a file, prepended with `@`, is passed.
This file then contains all the various arguments that we want to pass to the
linker.
Closes#41190
Include rustc in the default `./x.py install`
The default install used to include rustc, rust-std, and rust-docs, but
the refactoring in commit 6b3413d825 make rustc only default in
extended builds. This commit makes rustc installed by default again.
Make slice::split_at_mut example demonstrate mutability
Moved the examples from split_at_mut to split_at so the example at
split_at_mut can just demonstrate mutability.
See #44314
r? @steveklabnik
rustbook: remove dead test functions
There is no "test" subcommand added to the `clap::App`, so this is all dead code.
Cc @steveklabnik -- your [commit](a076961fd0) introducing this stated the intention of having both commands, but it seems nobody has missed the `test` command since February.
impl Debug for SplitWhitespace.
This one got missed because `libstd_unicode` doesn't have a `deny(missing_debug_implementations)` like `libstd` and `libcore`. I think that perhaps this lint should check for items exported from other crates too.
Minor documentation improvements for StmtKind
Documentation for Semi and Marco StmtKinds.
Wasn't obvious to me what these were when writing a lint recently.
update unimplemented! docs
For #42628 (updating docs from changes from #42155).
Initial changes made to make `unimplemented!` doc comments look more like `unreachable!` and remove statement about the panic message.
r? @steveklabnik
