bors [Fri, 4 May 2018 05:38:18 +0000 (05:38 +0000)]
Auto merge of #50398 - llogiq:memchr-nano-opt, r=nagisa
nano-optimization for memchr::repeat_byte
This replaces the multiple shifts & bitwise or with a single multiplication
In my benchmarks this performs equally well or better, especially on 64bit systems (it shaves a stable nanosecond on my skylake). This may go against conventional wisdom, but the shifts and bitwise ors cannot be pipelined because of hard data dependencies.
While it may or may not be worthwile from an optimization standpoint, it also reduces code size, so there's basically no downside.
bors [Fri, 4 May 2018 02:58:37 +0000 (02:58 +0000)]
Auto merge of #50433 - nrc:update, r=alexcrichton
Update RLS and Rustfmt (and Cargo)
Updates RLS and Rustfmt (the latter fixing tests). Cargo is updated too (to fix RLS tests), but that is covered by https://github.com/rust-lang/rust/pull/50417, so probably won't do much.
bors [Fri, 4 May 2018 00:16:41 +0000 (00:16 +0000)]
Auto merge of #50397 - sgrif:sg-smaller-universe-refactorings, r=nikomatsakis
Refactorings in preparation for the removal of the leak check
This contains all of the commits from #48407 that I was able to pull out on their own. This has most of the refactoring/ground work to unblock other work, but without the behavior changes that still need a crater run and NLL changes.
bors [Thu, 3 May 2018 20:45:54 +0000 (20:45 +0000)]
Auto merge of #50413 - kennytm:rollup, r=kennytm
Rollup of 12 pull requests
Successful merges:
- #50302 (Add query search order check)
- #50320 (Fix invalid path generation in rustdoc search)
- #50349 (Rename "show type declaration" to "show declaration")
- #50360 (Clarify wordings of the `unstable_name_collision` lint.)
- #50365 (Use two vectors in nearest_common_ancestor.)
- #50393 (Allow unaligned reads in constants)
- #50401 (Revert "Implement FromStr for PathBuf")
- #50406 (Forbid constructing empty identifiers from concat_idents)
- #50407 (Always inline simple BytePos and CharPos methods.)
- #50416 (check if the token is a lifetime before parsing)
- #50417 (Update Cargo)
- #50421 (Fix ICE when using a..=b in a closure.)
kennytm [Thu, 3 May 2018 18:16:39 +0000 (02:16 +0800)]
Rollup merge of #50406 - ExpHP:concat-nonzero-idents, r=dtolnay
Forbid constructing empty identifiers from concat_idents
The empty identifier is a [reserved identifier](https://github.com/rust-lang/rust/blob/8a37c75a3a661385cc607d934c70e86a9eaf5fd7/src/libsyntax_pos/symbol.rs#L300-L305) in rust, apparently used for black magicks like representing the crate root or somesuch... and therefore, being able to construct it is Ungood. Presumably.
...even if the macro that lets you construct it is so useless that you can't actually do any damage with it. (and believe me, I tried)
Fixes #50403.
**Note:** I noticed that when you try to do something similar with `proc_macro::Term`, the compiler actually catches it and flags the identifier as reserved. Perhaps a better solution would be to somehow have that same check applied here.
The libs team was discussing https://github.com/rust-lang/rust/issues/44431 today and the changes originally added in https://github.com/rust-lang/rust/pull/48292 and the conclusion was that we'd like to revert this for now until `!` is stable. This'll provide us maximal flexibility to tweak the error type here in the future, and it looks like `!` is close-ish to stabilization so hopefully this won't be delayed for too long.
kennytm [Thu, 3 May 2018 08:11:31 +0000 (16:11 +0800)]
Rollup merge of #50365 - nnethercote:nearest_common_ancestor-two-vecs, r=nikomatsakis
Use two vectors in nearest_common_ancestor.
When looking at any scope in scope chain A, we only need to look for
matches among scopes previously seen in scope chain B, and vice versa.
This halves the number of "seen before?" comparisons, speeding up some
runs of style-servo, clap-rs, and syn by 1--2%.
bors [Thu, 3 May 2018 08:06:08 +0000 (08:06 +0000)]
Auto merge of #50391 - nnethercote:escape_unicode, r=eddyb
Use escape_default() for strings in LitKind::token().
This avoids converting every char to \u{...} form, which bloats the
resulting strings unnecessarily. It also provides consistency with the
existing escape_default() calls in LitKind::token() used for raw
string literals, char literals, and raw byte char literals.
There are two benefits from this change.
- Compilation is faster. Most of the rustc-perf benchmarks see a
non-trivial speedup, particularly for incremental rebuilds, with the
best speedup over 13%, and multiple others over 10%.
- Generated rlibs are smaller. An extreme example is libfutures.rlib,
which shrinks from 2073306 bytes to 1765927 bytes, a 15% reduction.
r? @jseyfried
<details><summary>Here are full numbers for all the rustc-perf runs where the improvement was > 1%.</summary>
bors [Thu, 3 May 2018 05:38:11 +0000 (05:38 +0000)]
Auto merge of #50378 - varkor:repr-align-max-29, r=eddyb
Reduce maximum repr(align(N)) to 2^29
The current maximum `repr(align(N))` alignment is larger than the maximum alignment accepted by LLVM, which can cause issues for huge values of `N`, as seen in #49492. Fixes #49492.
bors [Thu, 3 May 2018 02:01:04 +0000 (02:01 +0000)]
Auto merge of #50369 - pftbest:unicode, r=SimonSapin
Fix a warning in libcore on 16bit targets.
This code is assuming that usize >= 32bits, but it is not the case on
16bit targets. It is producing a warning that can fail the compilation
on MSP430 if deny(warnings) is enabled.
It is very unlikely that someone would actually use this code on
a microcontroller, but since unicode was merged into libcore we
have to compile it on 16bit targets.
I've tried to make sure that the code stays the same on x86,
here is an assembly comparison: https://godbolt.org/g/wFw7dZ
Use escape_default() for strings in LitKind::token().
This avoids converting every char to \u{...} form, which bloats the
resulting strings unnecessarily. It also provides consistency with the
existing escape_default() calls in LitKind::token() used for raw
string literals, char literals, and raw byte char literals.
There are two benefits from this change.
- Compilation is faster. Most of the rustc-perf benchmarks see a
non-trivial speedup, particularly for incremental rebuilds, with the
best speedup over 13%, and multiple others over 10%.
- Generated rlibs are smaller. An extreme example is libfutures.rlib,
which shrinks from 2073306 bytes to 1765927 bytes, a 15% reduction.
bors [Wed, 2 May 2018 20:33:31 +0000 (20:33 +0000)]
Auto merge of #50355 - petrochenkov:50187, r=oli-obk
Fix an unresolved import issue with enabled `use_extern_macros`
This is a kinda ugly special-purpose solution that will break if we suddenly add a fourth namespace, but I hope to come up with something more general if I get to import resolution refactoring this summer.
Fixes https://github.com/rust-lang/rust/issues/50187 thus removing a blocker for stabilization of `use_extern_macros`
bors [Wed, 2 May 2018 17:02:25 +0000 (17:02 +0000)]
Auto merge of #50354 - varkor:initial-field-alignment-c-int, r=eddyb
Correct initial field alignment for repr(C)/repr(int)
Fixes #50098 following https://github.com/rust-lang/rust/issues/50098#issuecomment-385497333.
(I wasn't sure which kind of test was best suited here — I picked run-pass simply because that was convenient, but if codegen is more appropriate, let me know and I'll change it.)
Sean Griffin [Wed, 7 Feb 2018 18:17:31 +0000 (11:17 -0700)]
change skolemizations to use universe index
This is sort of confusing "side step". All it does is to change the
representation of a skolemized region. but the source of that universe
index is not the inference context, which is what we eventually want,
but rather an internal counter in the region inference context.
We'll patch that up later. But doing this now ought to help with
confusing diffs later.
Sean Griffin [Wed, 7 Feb 2018 17:27:42 +0000 (10:27 -0700)]
add universes to type inference variables
This gives each type inference variable a notion of universe but doesn't
do anything with it. We can always get the "current universe" from
infer_ctxt. This relies on the property of type variables that they can
never interact with siblings.
bors [Wed, 2 May 2018 02:10:51 +0000 (02:10 +0000)]
Auto merge of #50278 - eddyb:mir-succ-iter, r=nikomatsakis
rustc: return iterators from Terminator(Kind)::successors(_mut).
Minor cleanup (and potentially speedup) prompted by @nnethercote's `SmallVec` experiments.
This PR assumes `.count()` and `.nth(i)` on `iter::Chain<option::IntoIter, slice::Iter(Mut)>` are `O(1)`, but otherwise all of the uses appear to immediately iterate through the successors.
Conservatively assume dropping a generator touches its upvars, via locals' dtors.
This is meant to address rust-lang/rust#49918.
Review feedback: put back comment justifying skipping interior traversal.
Review feedback: dropck generators like trait objects: all their upvars must
outlive the generator itself, so just create a DtorckConstraint saying so.
bors [Tue, 1 May 2018 16:58:26 +0000 (16:58 +0000)]
Auto merge of #49789 - petrochenkov:prelext, r=nikomatsakis
Module experiments: Add one more prelude layer for extern crate names passed with `--extern`
Implements one item from https://internals.rust-lang.org/t/the-great-module-adventure-continues/6678/183
When some name is looked up in lexical scope (`name`, i.e. not module-relative scope `some_mod::name` or `::name`), it's searched roughly in the next order:
- local variables
- items in unnamed blocks
- items in the current module
- :sparkles: NEW! :sparkles: crate names passed with `--extern` ("extern prelude")
- standard library prelude (`Vec`, `drop`)
- language prelude (built-in types like `u8`, `str`, etc)
The last two layers contain a limited set of names controlled by us and not arbitrary user-defined names like upper layers. We want to be able to add new names into these two layers without breaking user code, so "extern prelude" names have higher priority than std prelude and built-in types.
This is a one-time breaking change, that's why it would be nice to run this through crater.
Practical impact is expected to be minimal though due to stylistic reasons (there are not many `Uppercase` crates) and due to the way how primitive types are resolved (https://github.com/rust-lang/rust/pull/32131).
This code is assuming that usize >= 32bits, but it is not the case on
16bit targets. It is producing a warning that will fail the compilation
on MSP430 if deny(warnings) is enabled.
It is very unlikely that someone would actually use this code on
a microcontroller, but since unicode was merged into libcore we
have compile it on 16bit targets.
When looking at any scope in scope chain A, we only need to look for
matches among scopes previously seen in scope chain B, and vice versa.
This halves the number of "seen before?" comparisons, speeding up some
runs of style-servo, clap-rs, and syn by 1--2%.
This reworks the force-frame-pointer PR to explicitly only consider the
value of the flag if it is provided, and use a target default otherwise.
Something that was tried but not kept was renaming the flag to
`frame-pointer`, because for flag `frame-pointer=no`, there is no
guarante, that LLVM will elide *all* the frame pointers; oposite of what
the literal reading of the flag would suggest.
Don't force-enable frame pointers when generating debug info
We apparently used to generate bad/incomplete debug info causing
debuggers not to find symbols of stack allocated variables. This was
somehow worked around by having frame pointers.
With the current codegen, this seems no longer necessary, so we can
remove the code that force-enables frame pointers whenever debug info
is requested.
Since certain situations, like profiling code profit from having frame
pointers, we add a -Cforce-frame-pointers flag to always enable frame
pointers.
bors [Tue, 1 May 2018 00:16:16 +0000 (00:16 +0000)]
Auto merge of #50197 - nikomatsakis:skolemize-out-of-tcx, r=eddyb
move skolemized regions into global tcx
Experimental branch to move skolemized regions into global tcx. This is probably not what we want long term but may be convenient to unblock @sgrif in the short term.
I'd like to do a perf run, though the main concern I guess would be memory usage.