was the major use-case, and to update the dep-graph. Other kinds of
predicates are now excluded from the cache because there is no easy way
to make a good dep-graph node for them, and because they are not
believed to be that useful. :)
Fixes#30741. (However, the test still gives wrong result for trans,
for an independent reason which is fixed in the next commit.)
This commit stabilizes and deprecates the FCP (final comment period) APIs for
the upcoming 1.7 beta release. The specific APIs which changed were:
Stabilized
* `Path::strip_prefix` (renamed from `relative_from`)
* `path::StripPrefixError` (new error type returned from `strip_prefix`)
* `Ipv4Addr::is_loopback`
* `Ipv4Addr::is_private`
* `Ipv4Addr::is_link_local`
* `Ipv4Addr::is_multicast`
* `Ipv4Addr::is_broadcast`
* `Ipv4Addr::is_documentation`
* `Ipv6Addr::is_unspecified`
* `Ipv6Addr::is_loopback`
* `Ipv6Addr::is_unique_local`
* `Ipv6Addr::is_multicast`
* `Vec::as_slice`
* `Vec::as_mut_slice`
* `String::as_str`
* `String::as_mut_str`
* `<[T]>::clone_from_slice` - the `usize` return value is removed
* `<[T]>::sort_by_key`
* `i32::checked_rem` (and other signed types)
* `i32::checked_neg` (and other signed types)
* `i32::checked_shl` (and other signed types)
* `i32::checked_shr` (and other signed types)
* `i32::saturating_mul` (and other signed types)
* `i32::overflowing_add` (and other signed types)
* `i32::overflowing_sub` (and other signed types)
* `i32::overflowing_mul` (and other signed types)
* `i32::overflowing_div` (and other signed types)
* `i32::overflowing_rem` (and other signed types)
* `i32::overflowing_neg` (and other signed types)
* `i32::overflowing_shl` (and other signed types)
* `i32::overflowing_shr` (and other signed types)
* `u32::checked_rem` (and other unsigned types)
* `u32::checked_shl` (and other unsigned types)
* `u32::saturating_mul` (and other unsigned types)
* `u32::overflowing_add` (and other unsigned types)
* `u32::overflowing_sub` (and other unsigned types)
* `u32::overflowing_mul` (and other unsigned types)
* `u32::overflowing_div` (and other unsigned types)
* `u32::overflowing_rem` (and other unsigned types)
* `u32::overflowing_neg` (and other unsigned types)
* `u32::overflowing_shl` (and other unsigned types)
* `u32::overflowing_shr` (and other unsigned types)
* `ffi::IntoStringError`
* `CString::into_string`
* `CString::into_bytes`
* `CString::into_bytes_with_nul`
* `From<CString> for Vec<u8>`
* `From<CString> for Vec<u8>`
* `IntoStringError::into_cstring`
* `IntoStringError::utf8_error`
* `Error for IntoStringError`
Deprecated
* `Path::relative_from` - renamed to `strip_prefix`
* `Path::prefix` - use `components().next()` instead
* `os::unix::fs` constants - moved to the `libc` crate
* `fmt::{radix, Radix, RadixFmt}` - not used enough to stabilize
* `IntoCow` - conflicts with `Into` and may come back later
* `i32::{BITS, BYTES}` (and other integers) - not pulling their weight
* `DebugTuple::formatter` - will be removed
* `sync::Semaphore` - not used enough and confused with system semaphores
Closes#23284
cc #27709 (still lots more methods though)
Closes#27712Closes#27722Closes#27728Closes#27735Closes#27729Closes#27755Closes#27782Closes#27798
This commit stabilizes and deprecates the FCP (final comment period) APIs for
the upcoming 1.7 beta release. The specific APIs which changed were:
Stabilized
* `Path::strip_prefix` (renamed from `relative_from`)
* `path::StripPrefixError` (new error type returned from `strip_prefix`)
* `Ipv4Addr::is_loopback`
* `Ipv4Addr::is_private`
* `Ipv4Addr::is_link_local`
* `Ipv4Addr::is_multicast`
* `Ipv4Addr::is_broadcast`
* `Ipv4Addr::is_documentation`
* `Ipv6Addr::is_unspecified`
* `Ipv6Addr::is_loopback`
* `Ipv6Addr::is_unique_local`
* `Ipv6Addr::is_multicast`
* `Vec::as_slice`
* `Vec::as_mut_slice`
* `String::as_str`
* `String::as_mut_str`
* `<[T]>::clone_from_slice` - the `usize` return value is removed
* `<[T]>::sort_by_key`
* `i32::checked_rem` (and other signed types)
* `i32::checked_neg` (and other signed types)
* `i32::checked_shl` (and other signed types)
* `i32::checked_shr` (and other signed types)
* `i32::saturating_mul` (and other signed types)
* `i32::overflowing_add` (and other signed types)
* `i32::overflowing_sub` (and other signed types)
* `i32::overflowing_mul` (and other signed types)
* `i32::overflowing_div` (and other signed types)
* `i32::overflowing_rem` (and other signed types)
* `i32::overflowing_neg` (and other signed types)
* `i32::overflowing_shl` (and other signed types)
* `i32::overflowing_shr` (and other signed types)
* `u32::checked_rem` (and other unsigned types)
* `u32::checked_neg` (and other unsigned types)
* `u32::checked_shl` (and other unsigned types)
* `u32::saturating_mul` (and other unsigned types)
* `u32::overflowing_add` (and other unsigned types)
* `u32::overflowing_sub` (and other unsigned types)
* `u32::overflowing_mul` (and other unsigned types)
* `u32::overflowing_div` (and other unsigned types)
* `u32::overflowing_rem` (and other unsigned types)
* `u32::overflowing_neg` (and other unsigned types)
* `u32::overflowing_shl` (and other unsigned types)
* `u32::overflowing_shr` (and other unsigned types)
* `ffi::IntoStringError`
* `CString::into_string`
* `CString::into_bytes`
* `CString::into_bytes_with_nul`
* `From<CString> for Vec<u8>`
* `From<CString> for Vec<u8>`
* `IntoStringError::into_cstring`
* `IntoStringError::utf8_error`
* `Error for IntoStringError`
Deprecated
* `Path::relative_from` - renamed to `strip_prefix`
* `Path::prefix` - use `components().next()` instead
* `os::unix::fs` constants - moved to the `libc` crate
* `fmt::{radix, Radix, RadixFmt}` - not used enough to stabilize
* `IntoCow` - conflicts with `Into` and may come back later
* `i32::{BITS, BYTES}` (and other integers) - not pulling their weight
* `DebugTuple::formatter` - will be removed
* `sync::Semaphore` - not used enough and confused with system semaphores
Closes#23284
cc #27709 (still lots more methods though)
Closes#27712Closes#27722Closes#27728Closes#27735Closes#27729Closes#27755Closes#27782Closes#27798
This PR introduces an `ObligationForest` data structure that the fulfillment context can use to track what's going on, instead of the current flat vector. This enables a number of improvements:
1. transactional support, at least for pushing new obligations
2. remove the "errors will be reported" hack -- instead, we only add types to the global cache once their entire subtree has been proven safe. Before, we never knew when this point was reached because we didn't track the subtree.
- this in turn allows us to limit coinductive reasoning to structural traits, which sidesteps #29859
3. keeping the backtrace should allow for an improved error message, where we give the user full context
- we can also remove chained obligation causes
This PR is not 100% complete. In particular:
- [x] Currently, types that embed themselves like `struct Foo { f: Foo }` give an overflow when evaluating whether `Foo: Sized`. This is not a very user-friendly error message, and this is a common beginner error. I plan to special-case this scenario, I think.
- [x] I should do some perf. measurements. (Update: 2% regression.)
- [x] More tests targeting #29859
- [ ] The transactional support is not fully integrated, though that should be easy enough.
- [ ] The error messages are not taking advantage of the backtrace.
I'd certainly like to do 1 through 3 before landing, but 4 and 5 could come as separate PRs.
r? @aturon // good way to learn more about this part of the trait system
f? @arielb1 // already knows this part of the trait system :)
to get the `Sized` error usable, since that hits new users
frequently. Further work is needed for the error reporting for non-Sized
cycle cases; those currently just fallback to the old path. Also adjust tests.
this makes sure the checks run before typeck (which might use the constant or const
function to calculate an array length) and gives prettier error messages in case of for
loops and such (since they aren't expanded yet).
fixes#30887
r? @pnkfelix
This adds back the raw_pointer_derive lint as a 'removed' lint, so that its removal does not cause errors (#30346) but warnings.
In the process I discovered regressions in the code for renamed and removed lints, which didn't appear to have any tests. The addition of a second lint pass (ast vs. hir) meant that attributes were being inspected twice, renamed and removed warnings printed twice. I restructured the code so these tests are only done once and added tests. Unfortunately it makes the patch more complicated for the needed beta backport.
r? @nikomatsakis
This provides limited support for using associated consts on type parameters. It generally works on things that can be figured out at trans time. This doesn't work for array lengths or match arms. I have another patch to make it work in const expressions.
CC @eddyb @nikomatsakis
In my PR for #21659 I accidentally used `// | help` as test annotation. This PR updates it to `//~| help`. I also found and updated 2 other tests with the same issue.
this makes sure the checks run before typeck (which might use the constant or const
function to calculate an array length) and gives prettier error messages in case of for
loops and such (since they aren't expanded yet).
This is an alternative to https://github.com/rust-lang/rust/pull/29954 for fixing #29857 that seems to me to be more inline with the general strategy around `TyError`. It also includes the fix for #30589 -- in fact, just the minimal change of making `ty_is_local` tolerate `TyError` avoids the ICE, but you get a lot of duplicate error reports, so in the case where the impl's trait reference already includes `TyError`, we just ignore the impl altogether.
cc @arielb1 @sanxiyn
Fixes#29857.
Fixes#30589.
Downgrade unit struct match via S(..) warnings to errors
The error signalling was introduced in #29383
It was noted as a warning-cycle-less regression in #30379Fix#30379
macro future proofing rules.
(We may want to think about what this test was actually testing and
figure out a way to test it without running afoul of macro future
proofing. I spent some time trying to do this, e.g. by inserting
parenthesis in the macro input pattern, but I could not quickly get it
working, so I took this tack instead.)
It was recently realized that we accept defaulted type parameters everywhere, without feature gate, even though the only place that we really *intended* to accept them were on types. This PR adds a lint warning unless the "type-parameter-defaults" feature is enabled. This should eventually become a hard error.
This is a [breaking-change] in that new feature gates are required (or simply removing the defaults, which is probably a better choice as they have little effect at this time). Results of a [crater run][crater] suggest that approximately 5-15 crates are affected. I didn't do the measurement quite right so that run cannot distinguish "true" regressions from "non-root" regressions, but even the upper bound of 15 affected crates seems relatively minimal.
[crater]: https://gist.github.com/nikomatsakis/760c6a67698bd24253bf
cc @rust-lang/lang
r? @pnkfelix
The motivation (other than removing boilerplate) is that this is a baby step towards a parser with error recovery.
[breaking-change] if you use any of the changed functions, you'll need to remove a try! or panictry!
This is roughly the same as my previous PR that created a dependency graph, but that:
1. The dependency graph is only optionally constructed, though this doesn't seem to make much of a difference in terms of overhead (see measurements below).
2. The dependency graph is simpler (I combined a lot of nodes).
3. The dependency graph debugging facilities are much better: you can now use `RUST_DEP_GRAPH_FILTER` to filter the dep graph to just the nodes you are interested in, which is super help.
4. The tests are somewhat more elaborate, including a few known bugs I need to fix in a second pass.
This is potentially a `[breaking-change]` for plugin authors. If you are poking about in tcx state or something like that, you probably want to add `let _ignore = tcx.dep_graph.in_ignore();`, which will cause your reads/writes to be ignored and not affect the dep-graph.
After this, or perhaps as an add-on to this PR in some cases, what I would like to do is the following:
- [x] Write-up a little guide to how to use this system, the debugging options available, and what the possible failure modes are.
- [ ] Introduce read-only and perhaps the `Meta` node
- [x] Replace "memoization tasks" with node from the map itself
- [ ] Fix the shortcomings, obviously! Notably, the HIR map needs to register reads, and there is some state that is not yet tracked. (Maybe as a separate PR.)
- [x] Refactor the dep-graph code so that the actual maintenance of the dep-graph occurs in a parallel thread, and the main thread simply throws things into a shared channel (probably a fixed-size channel). There is no reason for dep-graph construction to be on the main thread. (Maybe as a separate PR.)
Regarding performance: adding this tracking does add some overhead, approximately 2% in my measurements (I was comparing the build times for rustdoc). Interestingly, enabling or disabling tracking doesn't seem to do very much. I want to poke at this some more and gather a bit more data -- in some tests I've seen that 2% go away, but on others it comes back. It's not entirely clear to me if that 2% is truly due to constructing the dep-graph at all.
The next big step after this is write some code to dump the dep-graph to disk and reload it.
r? @michaelwoerister
