fix: Panic while canonicalizing erroneous projection type
Fixes#17866
The root cause of #17866 is quite horrifyng 😨
```rust
trait T {
type A;
}
type Foo = <S as T>::A; // note that S isn't defined
fn main() {
Foo {}
}
```
While inferencing alias type `Foo = <S as T>::A`;
78c2bdce86/crates/hir-ty/src/infer.rs (L1388-L1398)
the error type `S` in it is substituted by inference var in L1396 above as below;
78c2bdce86/crates/hir-ty/src/infer/unify.rs (L866-L869)
This new inference var's index is `1`, as the type inferecing procedure here previously inserted another inference var into same `InferenceTable`.
But after that, the projection type made from the above then passed to the following function;
78c2bdce86/crates/hir-ty/src/traits.rs (L88-L96)
here, a whole new `InferenceTable` is made, without any inference var and in the L94, this table calls;
78c2bdce86/crates/hir-ty/src/infer/unify.rs (L364-L370)
And while registering `AliasEq` `obligation`, this obligation contains inference var `?1` made from the previous table, but this table has only one inference var `?0` made at L365.
So, the chalk panics when we try to canonicalize that obligation to register it, because the obligation contains an inference var `?1` that the canonicalizing table doesn't have.
Currently, we are calling `InferenceTable::new()` to do some normalizing, unifying or coercing things to some targets that might contain inference var that the new table doesn't have.
I think that this is quite dangerous footgun because the inference var is just an index that does not contain the information which table does it made from, so sometimes this "foreign" index might cause panic like this case, or point at the wrong variable.
This PR mitigates such behaviour simply by inserting sufficient number of inference vars to new table to avoid such problem.
This strategy doesn't harm current r-a's intention because the inference vars that passed into new tables are just "unresolved" variables in current r-a, so this is just making sure that such "unresolved" variables exist in the new table
internal: Be more resilient to bad language item definitions in binop inference
Fixes#16287Fixes#16286
There's one more in `write_fn_trait_method_resolution`, but I'm not sure if it won't cause further problems in `infer_closures`.
Fix blessing of rmake tests
Fixes#129038.
When running in `--bless` mode, we now set the value of `RUSTC_BLESS_TEST` to the current test's source directory. This allows the diff helper in `run_make_support` to find the original snapshot file in the source directory and bless that, instead of unhelpfully blessing the temporary copy in `build`.
r? `@jieyouxu`
Slightly refactor `TargetSelection` in bootstrap
Mostly a drive-by refactoring of `TargetSelection` to reduce some manual "windows-gnu" detection and also accesses to the `triple` field.
r? `@onur-ozkan`
bootstrap: don't use rustflags for `--rustc-args`
r? `@onur-ozkan`
This is going to require a bit of context.
https://github.com/rust-lang/rust/pull/47558 has added `--rustc-args` to `./x test` to allow passing flags when building `compiletest` tests. It was made specifically because using `RUSTFLAGS` would rebuild the compiler/stdlib, which would in turn require the flag you want to build tests with to successfully bootstrap.
#113178 made the request that it also works for other tests and doctests. This is not trivial to support across the board for `library`/`compiler` unit-tests/doctests and across stages. This issue was closed in #113948 by using `RUSTFLAGS`, seemingly incorrectly since https://github.com/rust-lang/rust/pull/123489 fixed that part to make it work.
Unfortunately #123489/#113948 have regressed the goals of `--rustc-args`:
- now we can't use rustc args that don't bootstrap, to run the UI tests: we can't test incomplete features. The new trait solver doesn't bootstrap, in-progress borrowck/polonius changes don't bootstrap, some other features are similarly incomplete, etc.
- using the flag now rebuilds everything from scratch: stage0 stdlib, stage1 compiler, stage1 stdlib. You don't need to re-do all this to compile UI tests, you only need the latter to run stdlib tests with a new flag, etc. This happens for contributors, but also on CI today. (Not to mention that in doing that it will rebuild things with flags that are not meant to be used, e.g. stdlib cfgs that don't exist in the compiler; or you could also imagine that this silently enables flags that were not meant to be enabled in this way).
Since then, https://github.com/rust-lang/rust/pull/125011/commits/bd71c71ea04b4a4f954e579c2a6d44113274846a has started using it to test a stdlib feature, relying on the fact that it now rebuilds everything. So #125011 also regressed CI times more than necessary because it rebuilds everything instead of just stage 1 stdlib.
It's not easy for me to know how to properly fix#113178 in bootstrap, but #113948/#123489 are not it since they regress the initial intent. I'd think bootstrap would have to know from the list of test targets that are passed that the `library` or `compiler` paths that are passed could require rebuilding these crates with different rustflags, probably also depending on stages. Therefore I would not be able to fix it, and will just try in this PR to unregress the situation to unblock the initial use-case.
It seems miri now also uses `./x miri --rustc-args` in this incorrect meaning to rebuild the `library` paths they support to run with the new args. I've not made any bootstrap changes related to `./x miri` in this PR, so `--rustc-args` wouldn't work there anymore. I'd assume this would need to use rustflags again but I don't know how to make that work properly in bootstrap, hence opening as draft, so you can tell me how to do that. I assume we don't want to break their use-case again now that it exists, even though there are ways to use `./x test` to do exactly that.
`RUSTFLAGS_NOT_BOOTSTRAP=flag ./x test library/std` is a way to run unit tests with a new flag without rebuilding everything, while with #123489 there is no way anymore to run tests with a flag that doesn't bootstrap.
---
edit: after review, this PR:
- renames `./x test --rustc-args` to `./x test --compiletest-rustc-args` as it only applies there, and cannot use rustflags for this purpose.
- fixes the regression that using these args rebuilt everything from scratch
- speeds up some CI jobs via the above point
- removes `./x miri --rustc-args` as only library tests are supported, needs to rebuild libstd, and `./x miri --compiletest-rustc-args` wouldn't work since compiletests are not supported.
miri: make vtable addresses not globally unique
Miri currently gives vtables a unique global address. That's not actually matching reality though. So this PR enables Miri to generate different addresses for the same type-trait pair.
To avoid generating an unbounded number of `AllocId` (and consuming unbounded amounts of memory), we use the "salt" technique that we also already use for giving constants non-unique addresses: the cache is keyed on a "salt" value n top of the actually relevant key, and Miri picks a random salt (currently in the range `0..16`) each time it needs to choose an `AllocId` for one of these globals -- that means we'll get up to 16 different addresses for each vtable. The salt scheme is integrated into the global allocation deduplication logic in `tcx`, and also used for functions and string literals. (So this also fixes the problem that casting the same function to a fn ptr over and over will consume unbounded memory.)
r? `@saethlin`
Fixes https://github.com/rust-lang/miri/issues/3737
bootstrap: clear miri ui-test deps when miri sysroot gets rebuilt
Second attempt after https://github.com/rust-lang/rust/pull/128683: seems like it's not the compiler changing that we care about, but the sysroot changing.
I did some local testing with sysroot rebuilds and it works fine for at least those cases I checked.
r? ``@onur-ozkan``
Fix codegen-units tests that were disabled 8 years ago
I don't know if any of these tests still have value. They were disabled by https://github.com/rust-lang/rust/pull/33890, and we've survived without them for a while. But considering how small this test suite is, maybe it's worth having them.
I also had to add some normalization to the codegen-units tests output. I think the fact that I had to add some underscores how poor our test coverage is.
Slightly refactor `Flags` in bootstrap
The next step for https://github.com/rust-lang/rust/issues/126819 is to track commands executed inside `Config::parse`. This is quite challenging, because (tracked) command execution needs to access some state that is stored inside `Config`, which creates a sort of a chicken-and-egg problem.
I would like to first untangle `Config::parse` a little bit, which is what this PR starts with.
Tracking issue: https://github.com/rust-lang/rust/issues/126819
r? `@onur-ozkan`
fix: Resolve included files to their calling modules in IDE layer
Fixes https://github.com/rust-lang/rust-analyzer/issues/17390 at the expense of reporting duplicate diagnostics for modules that have includes in them when both the calling and called file are included.
internal: Reply to requests with defaults when vfs is still loading
There is no reason for us to hit the database with queries when we certainly haven't reached a stable state yet. Instead we just reply with default request results until we are in a state where we can do meaningful work. This should save us from wasting resources while starting up at worst, and at best save us from creating query and interning entries that are non-meaningful which ultimately just end up wasting memory.
