Auto merge of #26870 - jroesch:default-typaram-fallback, r=nikomatsakis
This PR completes [RFC 213](https://github.com/rust-lang/rfcs/blob/master/text/0213-defaulted-type-params.md) by allowing default type parameters to influence inference. This is almost certainly a breaking change due to interactions between default type parameters and the old fallback algorithm used for integral and floating point literals.
The error messages still require polish but I wanted to get early review and feedback from others on the the changes, error messages, and test cases. I also imagine we will want to run anywhere from 1-3 versions of this on crater and evaluate the impact, and it would be best to get that ball rolling.
The only outstanding issue I'm aware of is that type alias defaults don't work. It seems this may require significant restructuring, since during inference type aliases have already been expanded. @nikomatsakis might be able to provide some clarity here.
Jared Roesch [Mon, 13 Jul 2015 03:33:17 +0000 (20:33 -0700)]
Refactor the default type parameter algorithm
The algorithm was not correctly detecting conflicts after moving
defaults into TypeVariableValue. The updated algorithm
correctly detects and reports conflicts with information about
where the conflict occured and which items the defaults were
introduced by. The span's for said items are not being correctly
attached and still need to be patched.
Jared Roesch [Tue, 7 Jul 2015 22:50:02 +0000 (15:50 -0700)]
Implement Default TyParam fallback
This patch allows type parameter defaults to influence type inference. This is a possible breaking change since it effects the way type inference works and will have different behavior when mixing defaults and literal fallback.
Auto merge of #27258 - nikomatsakis:issue-26952, r=eddyb
Correct regression in type-inference caused by failing to reconfirm that
the object trait matches the required trait during trait selection. The
existing code was checking that the object trait WOULD match (in a
probe), but never executing the match outside of a probe.
This corrects various regressions observed in the wild, including
issue #26952. Fixes #26952.
Auto merge of #26630 - eefriedman:recursive-static, r=pnkfelix
***Edit: Fixed now.*** I'm pretty sure the way I'm using LLVMReplaceAllUsesWith here is
unsafe... but before I figure out how to fix that, I'd like a
reality-check: is this actually useful?
Auto merge of #27253 - bossmc:unbalanced-delimiters-cause-ice, r=nikomatsakis
This introduces a test for #23389 and improves the error behaviour to treat the malformed LHS as an error, not a compiler bug.
The parse phase that precedes the call to `check_lhs_nt_follows` could possibly be enhanced to police the format itself (which the old code suggests was the original intention), but I'm not sure that's any nicer than just parsing the matcher as generic rust code and then policing the specific requirements for being a macro matcher afterwards (as this does).
Auto merge of #26963 - Manishearth:improve-diag, r=steveklabnik
I'll be adding more commits to this PR as the weekend progresses. Was hoping to make this a mega-PR, but getting some eyes on this early would be nice too.
Steve Klabnik [Fri, 24 Jul 2015 18:56:04 +0000 (14:56 -0400)]
Rollup merge of #27244 - Detegr:master, r=eddyb
Hi all.
This is my first contribution to Rust and fixes an issue causing an invalid error message to be presented to the user when using unit struct as length of a repeat expression, issue #27008. The solution is based on suggestions by @oli-obk, but as I'm a complete newbie to this, I have no clue if I got them right :)
The biggest concern I have is that if the `NodeId` I'm returning is the correct one or not (it's not meaningful in this case but I think it would be nice to get it right).
Steve Klabnik [Fri, 24 Jul 2015 18:56:02 +0000 (14:56 -0400)]
Rollup merge of #27220 - AlisdairO:diagnostics120, r=Manishearth
As title!
I should probably be bunching these up a bit more, but I'm not sure when my time is going to disappear on me. Once my schedule stabilises I'll try to start batching them into larger PRs.
Steve Klabnik [Fri, 24 Jul 2015 18:56:01 +0000 (14:56 -0400)]
Rollup merge of #27177 - echochamber:master, r=steveklabnik
Was browsing somebody else's code and came across a snippet using labels. Looking around, it seems like there was an example for this in [rustbyexample](http://rustbyexample.com/flow_control/loop/nested.html) but none in trpl.
Auto merge of #27087 - nikomatsakis:closure-exploration, r=nrc
Refactors the "desugaring" of closures to expose the types of the upvars. This is necessary to be faithful with how actual structs work. The reasoning of the particular desugaring that I chose is explained in a fairly detailed comment.
As a side-effect, recursive closure types are prohibited unless a trait object intermediary is used. This fixes #25954 and also eliminates concerns about unrepresentable closure types that have infinite size, I believe. I don't believe this can cause regressions because of #25954.
(As for motivation, besides #25954 etc, this work is also intended as refactoring in support of incremental compilation, since closures are one of the thornier cases encountered when attempting to split node-ids into item-ids and within-item-ids. The goal is to eliminate the "internal def-id" distinction in astdecoding. However, I have to do more work on trans to really make progress there.)
Niko Matsakis [Fri, 24 Jul 2015 14:23:35 +0000 (10:23 -0400)]
Correct regression in type-inference caused by failing to reconfirm that
the object trait matches the required trait during trait selection. The
existing code was checking that the object trait WOULD match (in a
probe), but never executing the match outside of a probe.
This corrects various regressions observed in the wild, including
issue #26952. Fixes #26952.
Turns on the `in PLACE { BLOCK }` syntax, while leaving in support for the old `box (PLACE) EXPR` syntax (since we need to support that at least until we have a snapshot with support for `in PLACE { BLOCK }`.
(Note that we are not 100% committed to the `in PLACE { BLOCK }` syntax. In particular I still want to play around with some other alternatives. Still, I want to get the fundamental framework for the protocol landed so we can play with implementing it for non `Box` types.)
----
Also, this PR leaves out support for desugaring-based `box EXPR`. We will hopefully land that in the future, but for the short term there are type-inference issues injected by that change that we want to resolve separately.
Niko Matsakis [Fri, 17 Jul 2015 12:22:03 +0000 (08:22 -0400)]
Unify the upvar variables found in closures with the actual types of the
upvars after analysis is done. Remove the `closure_upvars` helper and
just consult this list of type variables directly.
Niko Matsakis [Fri, 17 Jul 2015 12:21:24 +0000 (08:21 -0400)]
Don't be so eager to call unresolved inference variables an error. MC
is being used now before the final regionck stage and in some cases SOME
amount of unresolved inference is OK. In fact, we could probably just
allow inference variables as well with only minimal pain.
Niko Matsakis [Fri, 17 Jul 2015 12:20:23 +0000 (08:20 -0400)]
Run the analysis process only once per closure, on the way up the tree.
This was the intention before but silly coding caused it to run twice if
there are nested closures.
Niko Matsakis [Thu, 16 Jul 2015 13:46:35 +0000 (09:46 -0400)]
Introduce ClosureSubsts rather than just having random fields in the
TyClosure variant; thread this through wherever closure substitutions
are expected, which leads to a net simplification. Simplify trans
treatment of closures in particular.
Auto merge of #27227 - eternaleye:patch-1, r=alexcrichton
Currently, `rustc` generates nondeterministic archives, which contain system timestamps. These don't really serve any useful purpose, and enabling deterministic archives moves us a little closer to completely deterministic builds. For a small toy library using `std::ops::{Deref,DerefMut}`, this change actually results in a bit-for-bit identical build every time.
Auto merge of #27208 - alexcrichton:msvc-less-dllimport, r=brson
Currently you can hit a link error on MSVC by only referencing static items from
a crate (no functions for example) and then link to the crate statically (as all
Rust crates do 99% of the time). A detailed investigation can be found [on
github][details], but the tl;dr is that we need to stop applying dllimport so
aggressively.
This commit alters the application of dllimport on constants to only cases where
the crate the constant originated from will be linked as a dylib in some output
crate type. That way if we're just linking rlibs (like the motivation for this
issue) we won't use dllimport. For the compiler, however, (which has lots of
dylibs) we'll use dllimport.
Auto merge of #27224 - alexcrichton:configure-lto-right, r=brson
The LTO pass in the compiler forgot to call the `LLVMRustAddBuilderLibraryInfo`
function and configure other options such as merge_functions, vectorize_slp,
etc. This ended up causing linker errors on MSVC targets because the optimizer
didn't have the right knowledge that some system functions are missing on these
platforms.
This commit consolidates creation of PassManagerBuilder instances to one
function which is then called when needed. This ensures that the pass manager is
always correctly configured with the various target-specific information that
LLVM needs.
Overall, this fixes `-C lto -C opt-level=3` on 32-bit MSVC targets.
Auto merge of #27221 - dotdash:no_empty_clean, r=luqmana
When compiling libsyntax this removes about 30k basic blocks that only
contain a single unconditional jump and reduces the peak memory usage by
about 10MB (from 681MB down to 671MB).