This first patch starts by moving around pieces of state related to
type checking. The goal is to slowly unify the type checking state
into a single typing context. This initial patch moves the
ParameterEnvironment into the InferCtxt and moves shared tables
from Inherited and ty::ctxt into their own struct Tables. This
is the foundational work to refactoring the type checker to
enable future evolution of the language and tooling.
It now says '#[feature] may not be used on the stable release channel'.
I had to convert this error from a lint to a normal compiler error.
I left the lint previously-used for this in place since removing it is
a breaking change. It will just go unused until the end of time.
Fixes#24125
It now says '#[feature] may not be used on the stable release channel'.
I had to convert this error from a lint to a normal compiler error.
I left the lint previously-used for this in place since removing it is
a breaking change. It will just go unused until the end of time.
Fixes#24125
This commit shards the broad `core` feature of the libcore library into finer
grained features. This split groups together similar APIs and enables tracking
each API separately, giving a better sense of where each feature is within the
stabilization process.
A few minor APIs were deprecated along the way:
* Iterator::reverse_in_place
* marker::NoCopy
The caching essentially eliminates "stability checking" time (my attempt to clean-up junk got tangled up with stability, so I added the caching while I was at it).
r? @eddyb
This is a port of @eddyb's `const-fn` branch. I rebased it, tweaked a few things, and added tests as well as a feature gate. The set of tests is still pretty rudimentary, I'd appreciate suggestions on new tests to write. Also, a double-check that the feature-gate covers all necessary cases.
One question: currently, the feature-gate allows the *use* of const functions from stable code, just not the definition. This seems to fit our usual strategy, and implies that we might (perhaps) allow some constant functions in libstd someday, even before stabilizing const-fn, if we were willing to commit to the existence of const fns but found some details of their impl unsatisfactory.
r? @pnkfelix
- add feature gate
- add basic tests
- adjust parser to eliminate conflict between `const fn` and associated
constants
- allow `const fn` in traits/trait-impls, but forbid later in type check
- correct some merge conflicts
It is hard to find the actual unstable feature which caused the error when using a list of stable and unstable features as the span marks the whole line
```
src/k8055.rs:22:1: 22:64 error: unstable feature
src/k8055.rs:22 #![feature(slice_patterns, rustc_private, core, convert, libc)]
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
```
This PR spawns an error for each unstable feature in the list:
```
est.rs:1:12: 1:26 error: unstable feature [-D unstable-features]
test.rs:1 #![feature(slice_patterns, rustc_private, core, convert, libc)]
^~~~~~~~~~~~~~
test.rs:1:28: 1:41 error: unstable feature [-D unstable-features]
test.rs:1 #![feature(slice_patterns, rustc_private, core, convert, libc)]
^~~~~~~~~~~~~
test.rs:1:43: 1:47 error: unstable feature [-D unstable-features]
test.rs:1 #![feature(slice_patterns, rustc_private, core, convert, libc)]
^~~~
test.rs:1:49: 1:56 error: unstable feature [-D unstable-features]
test.rs:1 #![feature(slice_patterns, rustc_private, core, convert, libc)]
^~~~~~~
test.rs:1:58: 1:62 error: unstable feature [-D unstable-features]
test.rs:1 #![feature(slice_patterns, rustc_private, core, convert, libc)]
^~~~
```
[breaking-change] Technically breaking, since code that had been using
these transmutes before will no longer compile. However, it was
undefined behavior, so really, it's a good thing. Fixing your code would
require some re-working to use an UnsafeCell instead.
Closes#13146
Puts implementations in bins hashed by the fast-reject key, and
only looks up the relevant impls, reducing O(n^2)-ishness
Before: 688.92user 5.08system 8:56.70elapsed 129%CPU (0avgtext+0avgdata 1208164maxresident)k, LLVM 379.142s
After: 637.78user 5.11system 8:17.48elapsed 129%CPU (0avgtext+0avgdata 1201448maxresident)k LLVM 375.552s
Performance increase is +7%-ish
