Fix ICE when `start` lang item has wrong generics
In my previous pr #87875 I missed the requirements on the `start` lang item due to its relative difficulty to test and opting for more conservative estimates. This fixes that by updating the requirement to be exactly one generic type.
The `start` lang item should have exactly one generic type for the return type of the `main` fn ptr passed to it. I believe having zero would previously *sometimes* compile (often with the use of `fn() -> ()` as the fn ptr but it was likely UB to call if the return type of `main` was not `()` as far as I know) however it also sometimes would not for various errors including ICEs and LLVM errors depending on exact situations. Having more than 1 generic has always failed with an ICE because only the one generic type is expected and provided.
Fixes#79559, fixes#73584, fixes#83117 (all duplicates)
Relevant to #9307
r? ````@cjgillot````
Update cargo
5 commits in 0121d66aa2ef5ffa9735f86c2b56f5fdc5a837a6..d56b42c549dbb7e7d0f712c51b39400260d114d4
2021-09-22 16:08:27 +0000 to 2021-09-27 13:44:18 +0000
- Allow `cargo update --precise` with metadata. (rust-lang/cargo#9945)
- Support path_in_vcs as part of cargo_vcs_metadata (rust-lang/cargo#9866)
- Doc about InstallTracker files and `install.root` (rust-lang/cargo#9948)
- Add some clarity on the license/license-file warning. (rust-lang/cargo#9941)
- Fix the problem that help cannot be displayed properly (rust-lang/cargo#9933)
Rollup of 8 pull requests
Successful merges:
- #87260 (Libgccjit codegen)
- #89212 (x.py: run `rustup toolchain link` in setup)
- #89233 (Hide `<...> defined here` note if the source is not available)
- #89235 (make junit output more consistent with default format)
- #89255 (Fix incorrect disambiguation suggestion for associated items)
- #89276 (Fix the population of the `union.impls` field)
- #89283 (Add regression test for issue #83564)
- #89318 (rustc_session: Remove lint store from `Session`)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Libgccjit codegen
This PR introduces a subtree for a gcc-based codegen backend to the repository, per decision in https://github.com/rust-lang/compiler-team/issues/442. We do not yet expect to ship this backend on nightly or run tests in CI, but we do verify that the backend checks (i.e., `cargo check`) successfully.
Work is expected to progress primarily in https://github.com/rust-lang/rustc_codegen_gcc, with semi-regular upstreaming, like with other subtrees.
Support incremental in compiletest for non-incremental modes.
This adds first-class support for using incremental builds in non-incremental-mode tests. These tests previously manually passed `-C incremental=tmp/foo` which resulted in reusing the same tmp folder between runs. This means that these tests could fail whenever the on-disk incremental format changed (such as when updating one's local source tree). This changes it so that these tests can pass a `// incremental-build` header which instructs compiletest to create a set aside a dedicated incremental directory which will be cleared before the test starts to ensure it has a clean slate.
Introduce `Rvalue::ShallowInitBox`
Polished version of #88700.
Implements MCP rust-lang/compiler-team#460, and should allow #43596 to go forward.
In short, creating an empty box is split from a nullary-op `NullOp::Box` into two steps, first a call to `exchange_malloc`, then a `Rvalue::ShallowInitBox` which transmutes `*mut u8` to a shallow-initialized `Box<T>`. This allows the `exchange_malloc` call to unwind. Details can be found in the MCP.
`NullOp::Box` is not yet removed, purely to make reverting easier in case anything goes wrong as the result of this PR. If revert is needed a reversion of "Use Rvalue::ShallowInitBox for box expression" commit followed by a test bless should be sufficient.
Experiments in #88700 showed a very slight compile-time perf regression due to (supposedly) slightly more time spent in LLVM. We could omit unwind edge generation (in non-`oom=panic` case) in box expression MIR construction to restore perf; but I don't think it's necessary since runtime perf isn't affected and perf difference is rather small.
Be explicit about using Binder::dummy
This is somewhat of a late followup to the binder refactor PR. It removes `ToPredicate` and `ToPolyTraitImpls` that hide the use of `Binder::dummy`. While this does make code a bit more verbose, it allows us be more careful about where we create binders.
Another alternative here might be to add a new trait `ToBinder` or something with a `dummy()` fn. Which could still allow grepping but allows doing something like `trait_ref.dummy()` (but I also wonder if longer-term, it would be better to be even more explicit with a `bind_with_vars(ty::List::empty())` *but* that's not clear yet.
r? ``@nikomatsakis``
Rollup of 12 pull requests
Successful merges:
- #88795 (Print a note if a character literal contains a variation selector)
- #89015 (core::ascii::escape_default: reduce struct size)
- #89078 (Cleanup: Remove needless reference in ParentHirIterator)
- #89086 (Stabilize `Iterator::map_while`)
- #89096 ([bootstrap] Improve the error message when `ninja` is not found to link to installation instructions)
- #89113 (dont `.ensure()` the `thir_abstract_const` query call in `mir_build`)
- #89114 (Fixes a technicality regarding the size of C's `char` type)
- #89115 (⬆️ rust-analyzer)
- #89126 (Fix ICE when `indirect_structural_match` is allowed)
- #89141 (Impl `Error` for `FromSecsError` without foreign type)
- #89142 (Fix match for placeholder region)
- #89147 (add case for checking const refs in check_const_value_eq)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Migrate in-tree crates to 2021
This replaces #89075 (cherry picking some of the commits from there), and closes#88637 and fixes#89074.
It excludes a migration of the library crates for now (see tidy diff) because we have some pending bugs around macro spans to fix there.
I instrumented bootstrap during the migration to make sure all crates moved from 2018 to 2021 had the compatibility warnings applied first.
Originally, the intent was to support cargo fix --edition within bootstrap, but this proved fairly difficult to pull off. We'd need to architect the check functionality to support running cargo check and cargo fix within the same x.py invocation, and only resetting sysroots on check. Further, it was found that cargo fix doesn't behave too well with "not quite workspaces", such as Clippy which has several crates. Bootstrap runs with --manifest-path ... for all the tools, and this makes cargo fix only attempt migration for that crate. We can't use e.g. --workspace due to needing to maintain sysroots for different phases of compilation appropriately.
It is recommended to skip the mass migration of Cargo.toml's to 2021 for review purposes; you can also use `git diff d6cd2c6c87 -I'^edition = .20...$'` to ignore the edition = 2018/21 lines in the diff.
This allows the format_args! macro to keep the pre-expansion code out of
the unsafe block without doing gymnastics with nested `match`
expressions. This reduces codegen.
Lower only one HIR owner at a time
Based on https://github.com/rust-lang/rust/pull/83723
Additional diff is here: https://github.com/cjgillot/rust/compare/ownernode...lower-mono
Lowering is very tangled and has a tendency to intertwine the transformation of different items. This PR aims at simplifying the logic by:
- moving global analyses to the resolver (item_generics_num_lifetimes, proc_macros, trait_impls);
- removing a few special cases (non-exported macros and use statements);
- restricting the amount of available information at any one time;
- avoiding back-and-forth between different owners: an item must now be lowered all at once, and its parent cannot refer to its nodes.
I also removed the sorting of bodies by span. The diagnostic ordering changes marginally, since definitions are pretty much sorted already according to the AST. This uncovered a subtlety in thir-unsafeck.
(While these items could logically be in different PRs, the dependency between commits and the amount of conflicts force a monolithic PR.)
This also adjusts the lint docs generation to accept (and ignore) an allow
attribute, rather than expecting the documentation to be immediately followed by
the lint name.
This just applies the suggested fixes from the compatibility warnings,
leaving any that are in practice spurious in. This is primarily intended to
provide a starting point to identify possible fixes to the migrations (e.g., by
avoiding spurious warnings).
A secondary commit cleans these up where they are false positives (as is true in
many of the cases).
Add initial support for m68k
This patch series adds initial support for m68k making use of the new M68k
backend introduced with LLVM-13. Additional changes will be needed to be
able to actually use the backend for this target.
Simplify lazy DefPathHash decoding by using an on-disk hash table.
This PR simplifies the logic around mapping `DefPathHash` values encountered during incremental compilation to valid `DefId`s in the current session. It is able to do so by using an on-disk hash table encoding that allows for looking up values directly, i.e. without deserializing the entire table.
The main simplification comes from not having to keep track of `DefPathHashes` being used during the compilation session.
Rollup of 8 pull requests
Successful merges:
- #87320 (Introduce -Z remap-cwd-prefix switch)
- #88690 (Accept `m!{ .. }.method()` and `m!{ .. }?` statements. )
- #88775 (Revert anon union parsing)
- #88841 (feat(rustc_typeck): suggest removing bad parens in `(recv.method)()`)
- #88907 (Highlight the `const fn` if error happened because of a bound on the impl block)
- #88915 (`Wrapping<T>` has the same layout and ABI as `T`)
- #88933 (Remove implementation of `min_align_of` intrinsic)
- #88951 (Update books)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Revert anon union parsing
Revert PR #84571 and #85515, which implemented anonymous union parsing in a manner that broke the context-sensitivity for the `union` keyword and thus broke stable Rust code.
Fix#88583.
