Add #[defines] attribute and require it for all type-alias-impl-trait sites that register a hidden type

[oli-obk]

Instead of relying on the signature of items to decide whether they are constraining an opaque type, the opaque types that the item constrains must be explicitly listed.

A previous version of this PR used an actual attribute, but had to keep the resolved DefIds in a side table.

Now we just lower to fields in the AST that have no surface syntax, instead a builtin attribute macro fills in those fields where applicable.

Note that for convenience referencing opaque types in associated types from associated methods on the same impl will not require an attribute. If that causes problems #[defines()] can be used to overwrite the default of searching for opaques in the signature.

One wart of this design is that closures and static items do not have generics. So since I stored the opaques in the generics of functions, consts and methods, I needed to add a custom field to closures and statics to track this information. It's not really worse than the work that had to be done for the attribute/side-table based design, just something to be aware of.

[bors]

☔ The latest upstream changes (presumably #128481) made this pull request unmergeable. Please resolve the merge conflicts.

[oli-obk]

@jdonszelmann what do you think about this? There's probably more opportunity for simplifying things, since name_or_empty is always empty for parsed attrs, but that should be its own PR

[rustbot]

Some changes occurred in compiler/rustc_attr_data_structures

cc @jdonszelmann

These commits modify the Cargo.lock file. Unintentional changes to Cargo.lock can be introduced when switching branches and rebasing PRs.

If this was unintentional then you should revert the changes before this PR is merged.
Otherwise, you can ignore this comment.

Some changes occurred in src/tools/rustfmt

cc @rust-lang/rustfmt

Some changes occurred in src/tools/clippy

cc @rust-lang/clippy

[oli-obk]

r? @lcnr maybe?

[rustbot]

rustc_error_messages was changed

cc @davidtwco, @compiler-errors, @TaKO8Ki

[oli-obk]

This test now lives in tests/ui/type-alias-impl-trait/path_resolution_taint.rs

[rust-log-analyzer]

The job mingw-check-tidy failed! Check out the build log: (web) (plain)

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info: removing rustup binaries
info: rustup is uninstalled
##[group]Image checksum input
mingw-check-tidy
# We use the ghcr base image because ghcr doesn't have a rate limit
# and the mingw-check-tidy job doesn't cache docker images in CI.
FROM ghcr.io/rust-lang/ubuntu:22.04
ARG DEBIAN_FRONTEND=noninteractive
RUN apt-get update && apt-get install -y --no-install-recommends \
  g++ \
  make \
---

COPY host-x86_64/mingw-check/validate-toolstate.sh /scripts/
COPY host-x86_64/mingw-check/validate-error-codes.sh /scripts/

# NOTE: intentionally uses python2 for x.py so we can test it still works.
# validate-toolstate only runs in our CI, so it's ok for it to only support python3.
ENV SCRIPT TIDY_PRINT_DIFF=1 python2.7 ../x.py test \
           --stage 0 src/tools/tidy tidyselftest --extra-checks=py,cpp
# This file is autogenerated by pip-compile with Python 3.10
# by the following command:
#
#    pip-compile --allow-unsafe --generate-hashes reuse-requirements.in
---
#12 3.671 WARNING: Running pip as the 'root' user can result in broken permissions and conflicting behaviour with the system package manager. It is recommended to use a virtual environment instead: https://pip.pypa.io/warnings/venv
#12 4.218 Collecting virtualenv
#12 4.275   Downloading virtualenv-20.29.2-py3-none-any.whl (4.3 MB)
#12 4.540      ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 4.3/4.3 MB 16.3 MB/s eta 0:00:00
#12 4.601 Collecting platformdirs<5,>=3.9.1
#12 4.612   Downloading platformdirs-4.3.6-py3-none-any.whl (18 kB)
#12 4.636 Collecting distlib<1,>=0.3.7
#12 4.662      ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 469.0/469.0 KB 32.6 MB/s eta 0:00:00
#12 4.703 Collecting filelock<4,>=3.12.2
#12 4.713   Downloading filelock-3.17.0-py3-none-any.whl (16 kB)
#12 4.713   Downloading filelock-3.17.0-py3-none-any.whl (16 kB)
#12 4.793 Installing collected packages: distlib, platformdirs, filelock, virtualenv
#12 4.975 Successfully installed distlib-0.3.9 filelock-3.17.0 platformdirs-4.3.6 virtualenv-20.29.2
#12 DONE 5.1s

#13 [7/8] COPY host-x86_64/mingw-check/validate-toolstate.sh /scripts/
#13 DONE 0.0s
---
DirectMap4k:      114624 kB
DirectMap2M:     8273920 kB
DirectMap1G:    10485760 kB
##[endgroup]
Executing TIDY_PRINT_DIFF=1 python2.7 ../x.py test            --stage 0 src/tools/tidy tidyselftest --extra-checks=py,cpp
+ TIDY_PRINT_DIFF=1 python2.7 ../x.py test --stage 0 src/tools/tidy tidyselftest --extra-checks=py,cpp
    Finished `dev` profile [unoptimized] target(s) in 0.05s
##[endgroup]
WARN: currently no CI rustc builds have rustc debug assertions enabled. Please either set `rust.debug-assertions` to `false` if you want to use download CI rustc or set `rust.download-rustc` to `false`.
downloading https://static.rust-lang.org/dist/2025-02-18/rustfmt-nightly-x86_64-unknown-linux-gnu.tar.xz
---
##[endgroup]
fmt check
fmt: checked 5856 files
tidy check
tidy error: /checkout/compiler/rustc_hir_analysis/messages.ftl: message `hir_analysis_tait_forward_compat` is not used
removing old virtual environment
removing old virtual environment
creating virtual environment at '/checkout/obj/build/venv' using 'python3.10' and 'venv'
creating virtual environment at '/checkout/obj/build/venv' using 'python3.10' and 'virtualenv'
Requirement already satisfied: pip in ./build/venv/lib/python3.10/site-packages (25.0.1)
All checks passed!
checking python file formatting
28 files already formatted
checking C++ file formatting
checking C++ file formatting
some tidy checks failed
Command has failed. Rerun with -v to see more details.
  local time: Wed Feb 26 12:05:36 UTC 2025
  network time: Wed, 26 Feb 2025 12:05:36 GMT
##[error]Process completed with exit code 1.
Post job cleanup.