Fix ICE #48984
* ~~fbf6423 The tail type was not normalized.~~
* d0839d5680 The method had a wrong assumption that something whose parent is a trait is an associated item. Fixes#48984.
Add `-C target-feature` to all functions
Previously the features specified to LLVM via `-C target-feature` were only
reflected in the `TargetMachine` but this change *also* reflects these and the
base features inside each function itself. This change matches clang and...
Closesrust-lang-nursery/stdsimd#427
Previously the features specified to LLVM via `-C target-feature` were only
reflected in the `TargetMachine` but this change *also* reflects these and the
base features inside each function itself. This change matches clang and...
Closesrust-lang-nursery/stdsimd#427
Implement LazyBTreeMap and use it in a few places.
This is a thin wrapper around BTreeMap that avoids allocating upon creation.
I would prefer to change BTreeMap directly to make it lazy (like I did with HashSet in #36734) and I initially attempted that by making BTreeMap::root an Option<>. But then I also had to change Iter and Range to handle trees with no root, and those types have stability markers on them and I wasn't sure if that was acceptable. Also, BTreeMap has a lot of complex code and changing it all was challenging, and I didn't have high confidence about my general approach.
So I prototyped this wrapper instead and used it in the hottest locations to get some measurements about the effect. The measurements are pretty good!
- Doing a debug build of serde, it reduces the total number of heap allocations from 17,728,709 to 13,359,384, a 25% reduction. The number of bytes allocated drops from 7,474,672,966 to 5,482,308,388, a 27% reduction.
- It gives speedups of up to 3.6% on some rustc-perf benchmark jobs. crates.io, futures, and serde benefit most.
```
futures-check
avg: -1.9% min: -3.6% max: -0.5%
serde-check
avg: -2.1% min: -3.5% max: -0.7%
crates.io-check
avg: -1.7% min: -3.5% max: -0.3%
serde
avg: -2.0% min: -3.0% max: -0.9%
serde-opt
avg: -1.8% min: -2.9% max: -0.3%
futures
avg: -1.5% min: -2.8% max: -0.4%
tokio-webpush-simple-check
avg: -1.1% min: -2.2% max: -0.1%
futures-opt
avg: -1.2% min: -2.1% max: -0.4%
piston-image-check
avg: -0.8% min: -1.1% max: -0.3%
crates.io
avg: -0.6% min: -1.0% max: -0.3%
```
@Gankro, how do you think I should proceed here? Is leaving this as a wrapper reasonable? Or should I try to make BTreeMap itself lazy? If so, can I change the representation of Iter and Range?
Thanks!
rustc_driver: Catch ICEs on the main thread too
#48575 introduced an optimization to run rustc directly on the main thread when possible. However, the threaded code detects panics when they `join()` to report as an ICE. When running directly, we need to use `panic::catch_unwind` to get the same effect.
cc @ishitatsuyuki
r? @alexcrichton
Added warning for unused arithmetic expressions
The compiler now displays a warning when a binary arithmetic operation is evaluated but not used. This resolves#50124 by following the instructions outlined in the issue. The changes are as follows:
- Added new pattern matching for unused arithmetic expressions in `src/librustc_lint/unused.rs`
- Added `#[must_use]` attributes to the binary operation methods in `src/libcore/internal_macros.rs`
- Added `#[must_use]` attributes to the non-assigning binary operators in `src/libcore/ops/arith.rs`
Access individual fields of tuples, closures and generators on drop.
Fixes#48623, by extending the change in #47917 to closures. Also does this for tuples and generators for consistency.
Enums are unchanged because there is now way to borrow `*enum.field` without borrowing `enum.field` at the moment, so any error would be reported when the enum goes out of scope. Unions aren't changed because unions they don't automatically drop their fields.
r? @nikomatsakis
rustc: Emit `uwtable` for allocator shims
This commit emits the `uwtable` attribute to LLVM for platforms that require it
for the allocator shims that we generate to ensure that they can hopefully get
unwound past. This is a stab in the dark at helping
https://bugzilla.mozilla.org/show_bug.cgi?id=1456150 along.
rustc: Disable threads in LLD for wasm
Upstream bug reports (rustwasm/wasm-bindgen#119) show that this may be the
culprit of odd crashes/hangs. The linker is a tiny fraction of build time anyway
right now so let's disable it and figure out how to possibly reenable it later
if necessary.
Add some utilities to `libsyntax`
Adds a few functions to `Mark` and `Span` that I found useful in an upcoming refactor of NLL region error reporting. Also includes some new documentation based on my discussion with @jseyfried on IRC.
r? @jseyfried
Remove hack around comparisons of i1 values (fixes#40980)
The regression test still passes without that 2 years old hack. The underlying
LLVM bug has probably been fixed upstream since then.
Partial future-proofing for Box<T, A>
In some ways, this is similar to @eddyb's PR #47043 that went stale, but doesn't cover everything. Notably, this still leaves Box internalized as a pointer in places, so practically speaking, only ZSTs can be practically added to the Box type with the changes here (the compiler ICEs otherwise).
The Box type is not changed here, that's left for the future because I want to test that further first, but this puts things in place in a way that hopefully will make things easier.
Rollup of 7 pull requests
Successful merges:
- #49707 (Add "the Rustc book")
- #50222 (Bump bootstrap compiler to 2018-04-24)
- #50227 (Fix ICE with erroneous `impl Trait` in a trait impl)
- #50229 (Add setting to go to item if there is only one result)
- #50231 (Add more doc aliases)
- #50246 (Make dump_{alloc,allocs,local}() no-ops when tracing is disabled.)
- #49894 (Rename InternedString to LocalInternedString and introduce a new thread-safe InternedString)
Failed merges:
Rename InternedString to LocalInternedString and introduce a new thread-safe InternedString
This is an allocation-free alternative to https://github.com/rust-lang/rust/pull/46972.
Make dump_{alloc,allocs,local}() no-ops when tracing is disabled.
Because they traverse data structures and build up strings, which is
wasted effort if those strings aren't printed.
The patch also removes some now-unnecessary log_enabled! tests at call
sites.
This is a big win for the Debug and Opt runs of coercions, tuple-stress, html5ever, and encoding.
```
coercions-opt
avg: -7.8% min: -14.8% max: 0.1%
coercions
avg: -8.0% min: -12.8% max: 0.1%
tuple-stress
avg: -7.2% min: -10.8% max: -0.7%
tuple-stress-opt
avg: -6.9% min: -10.7% max: 0.6%
html5ever
avg: -4.6% min: -7.3% max: -0.3%
encoding
avg: -2.4% min: -4.5% max: 0.1%
html5ever-opt
avg: -2.7% min: -4.2% max: -0.2%
encoding-opt
avg: -1.4% min: -2.4% max: 0.0%
```
