CFI: Support complex receivers
Right now, we only support rewriting `&self` and `&mut self` into `&dyn MyTrait` and `&mut dyn MyTrait`. This expands it to handle the full gamut of receivers by calculating the receiver based on *substitution* rather than based on a rewrite. This means that, for example, `Arc<Self>` will become `Arc<dyn MyTrait>` appropriately with this change.
This approach also allows us to support associated type constraints as well, so we will correctly rewrite `&self` into `&dyn MyTrait<T=i32>`, for example.
r? ```@workingjubilee```
CFI: Handle dyn with no principal
In user-facing Rust, `dyn` always has at least one predicate following it. Unfortunately, because we filter out marker traits from receivers at callsites and `dyn Sync` is, for example, legal, this results in us having `dyn` types with no predicates on occasion in our alias set encoding. This patch handles cases where there are no predicates in a `dyn` type which are relevant to its alias set.
Fixes#122998
r? workingjubilee
Clean up unnecessary headers/flags in coverage mir-opt tests
During #122542, I noticed that some of the headers and flags I had copied over from `tests/mir-opt/instrument_coverage.rs` were unnecessary. And while working to remove those, I noticed even more that could be removed or replaced.
Clarify transmute example
The example claims using an iterator will copy the entire vector, but this is not true in practice thanks to internal specializations in the stdlib (see https://godbolt.org/z/cnxo3MYs5 for confirmation that this doesn't reallocate nor iterate over the vec's elements). Since neither the copy nor the optimization is guaranteed I opted for saying that they _may_ happen.
Add more comments to the bootstrap code that handles `tests/coverage`
At the bootstrap level, coverage tests are a bit more complicated than other test suites, because we want to run the same set of test files in multiple different modes, in a way that's convenient and flexible when invoked manually.
This PR adds a few more comments to explain what's going on.
For the `MiddleDot` case, current behaviour:
- For a case like `1.2`, `sym1` is `1` and `sym2` is `2`, and `self.token`
holds `1.2`.
- It creates a new ident token from `sym1` that it puts into `self.token`.
- Then it does `bump_with` with a new dot token, which moves the `sym1`
token into `prev_token`.
- Then it does `bump_with` with a new ident token from `sym2`, which moves the
`dot` token into `prev_token` and discards the `sym1` token.
- Then it does `bump`, which puts whatever is next into `self.token`,
moves the `sym2` token into `prev_token`, and discards the `dot` token
altogether.
New behaviour:
- Skips creating and inserting the `sym1` and dot tokens, because they are
unnecessary.
- This also demonstrates that the comment about `Spacing::Alone` is
wrong -- that value is never used. That comment was added in #77250,
and AFAICT it has always been incorrect.
The commit also expands comments. I found this code hard to read
previously, the examples in comments make it easier.
Pass in the span for the field rather than using `prev_token`.
Also rename it `mk_expr_tuple_field_access`, because it doesn't do any
actual parsing, it just creates an expression with what it's given.
Not much of a clarity win by itself, but unlocks additional subsequent
simplifications.
Replace `mir_built` query with a hook and use mir_const everywhere instead
A small perf improvement due to less dep graph handling.
Mostly just a cleanup to get rid of one of our many mir queries
Previously, we only rewrote `&self` and `&mut self` receivers. By
instantiating the method from the trait definition, we can make this
work work with arbitrary legal receivers instead.
ci: Build gccjit from a git archive
A full `git clone` of GCC includes quite a lot of history, and it's
completely unnecessary for building it in CI. We can use a GitHub
archive URL to get a simple tarball that is much faster to download.
Also, the `gcc-build` directory can be removed after install to reduce
the image size even further.
In user-facing Rust, `dyn` always has at least one predicate following
it. Unfortunately, because we filter out marker traits from receivers at
callsites and `dyn Sync` is, for example, legal, this results in us
having `dyn` types with no predicates on occasion in our alias set
encoding. This patch handles cases where there are no predicates in a
`dyn` type which are relevant to its alias set.
Fixes#122998
Rollup of 10 pull requests
Successful merges:
- #122737 (conditionally ignore fatal diagnostic in the SilentEmitter)
- #122757 (Fixed the `private-dependency` bug)
- #122886 (add test for #90192)
- #122937 (Unbox and unwrap the contents of `StatementKind::Coverage`)
- #122949 (Add a regression test for #117310)
- #122962 (Track run-make-support lib in common inputs stamp)
- #122977 (Rename `Arguments::as_const_str` to `as_statically_known_str`)
- #122983 (Fix build failure on ARM/AArch64/PowerPC/RISC-V FreeBSD/NetBSD)
- #122984 (panic-in-panic-hook: formatting a message that's just a string is risk-free)
- #122992 (std:🧵 refine available_parallelism for solaris/illumos.)
r? `@ghost`
`@rustbot` modify labels: rollup
std:🧵 refine available_parallelism for solaris/illumos.
Rather than the system-wide available cpus fallback solution, we fetch the cpus bound to the current process.
panic-in-panic-hook: formatting a message that's just a string is risk-free
This slightly improves the output in the 'panic while processing panic' case if the panic message does not involve any formatting. Follow-up to https://github.com/rust-lang/rust/pull/122930.
r? ``@Amanieu``
Rename `Arguments::as_const_str` to `as_statically_known_str`
While `const` has a particular meaning about language guarantees, here
we need a fuzzier notion like whether constant propagation was
effective, and `statically_known` is the best term we have for now.
r? ``@RalfJung``
Track run-make-support lib in common inputs stamp
So that when the support library gets modified, `run-make` tests are forced to re-run instead of being still ignored as if nothing changed.
Fixes#122961.
Add a regression test for #117310Closes#117310
It seems to have been fixed in `rustc 1.79.0-nightly (1388d7a06 2024-03-20)` or before, so just adding a regression test for it.
Unbox and unwrap the contents of `StatementKind::Coverage`
The payload of coverage statements was historically a structure with several fields, so it was boxed to avoid bloating `StatementKind`.
Now that the payload is a single relatively-small enum, we can replace `Box<Coverage>` with just `CoverageKind`.
This patch also adds a size assertion for `StatementKind`, to avoid accidentally bloating it in the future.
``@rustbot`` label +A-code-coverage
Fixed the `private-dependency` bug
Fixed the private-dependency bug: If the directly dependent crate is loaded last and is not configured with `--extern`, it may be incorrectly set to `private-dependency`
Fixes#122756
conditionally ignore fatal diagnostic in the SilentEmitter
This change is primarily meant to allow rustfmt to ignore all diagnostics when using the `SilentEmitter`. Back in #121301 the `SilentEmitter` was shared between rustc and rustfmt. This changed rustfmt's behavior from ignoring all diagnostic to emitting fatal diagnostics, which lead to https://github.com/rust-lang/rustfmt/issues/6109.
These changes allow rustfmt to maintain its previous behaviour when using the `SilentEmitter`, while allowing rustc code to still emit fatal diagnostics.
Encode implied predicates for traits
In #112629, we decided to make associated type bounds in the "supertrait" AST position *implied* even though they're not supertraits themselves.
This means that the `super_predicates` and `implied_predicates` queries now differ for regular traits. The assumption that they didn't differ was hard-coded in #107614, so in cross-crate positions this means that we forget the implied predicates from associated type bounds.
This isn't unsound, just kind of annoying. This should be backported since associated type bounds are slated to stabilize for 1.78 -- either that, or associated type bounds can be reverted on beta and re-shipped in 1.79 with this patch.
Fixes#122859
CFI: Strip auto traits off Virtual calls
We already use `Instance` at declaration sites when available to glean additional information about possible abstractions of the type in use. This does the same when possible at callsites as well.
The primary purpose of this change is to allow CFI to alter how it generates type information for indirect calls through `Virtual` instances.
This is needed for the "separate machinery" version of my approach to the vtable issues (#122573), because we need to respond differently to a `Virtual` call to the same type as a non-virtual call, specifically [stripping auto traits off the receiver's `Self`](54b15b0c36) because there isn't a separate vtable for `Foo` vs `Foo + Send`.
This would also make a more general underlying mechanism that could be used by rcvalle's [proposed drop detection / encoding](edcd1e20a1) if we end up using his approach, as we could condition out on the `def_id` in the CFI code rather than requiring the generating code to explicitly note whether it was calling drop.
Matthias Krüger