Commit graph

17120 commits

Author SHA1 Message Date
bors
0ce1369bde Auto merge of #136974 - m-ou-se:fmt-options-64-bit, r=scottmcm
Reduce FormattingOptions to 64 bits

This is part of https://github.com/rust-lang/rust/issues/99012

This reduces FormattingOptions from 6-7 machine words (384 bits on 64-bit platforms, 224 bits on 32-bit platforms) to just 64 bits (a single register on 64-bit platforms).

Before:

```rust
pub struct FormattingOptions {
    flags: u32, // only 6 bits used
    fill: char,
    align: Option<Alignment>,
    width: Option<usize>,
    precision: Option<usize>,
}
```

After:

```rust
pub struct FormattingOptions {
    /// Bits:
    ///  - 0-20: fill character (21 bits, a full `char`)
    ///  - 21: `+` flag
    ///  - 22: `-` flag
    ///  - 23: `#` flag
    ///  - 24: `0` flag
    ///  - 25: `x?` flag
    ///  - 26: `X?` flag
    ///  - 27: Width flag (if set, the width field below is used)
    ///  - 28: Precision flag (if set, the precision field below is used)
    ///  - 29-30: Alignment (0: Left, 1: Right, 2: Center, 3: Unknown)
    ///  - 31: Always set to 1
    flags: u32,
    /// Width if width flag above is set. Otherwise, always 0.
    width: u16,
    /// Precision if precision flag above is set. Otherwise, always 0.
    precision: u16,
}
```
2025-03-22 10:56:14 +00:00
bors
db687889a5 Auto merge of #138719 - lcnr:concrete_opaque_types-closures, r=oli-obk
merge opaque types defined in nested bodies

A small step towards https://github.com/rust-lang/types-team/issues/129

r? `@oli-obk`
2025-03-22 06:55:52 +00:00
Matthias Krüger
bc46c98dd8
Rollup merge of #138721 - jchecahi:tests-explicit-cpus, r=tgross35
Use explicit cpu in some asm and codegen tests.

Some tests expect to be compiled for a specific CPU or require certain target features to be present (or absent). These tests work fine with default CPUs but fail in downstream builds for RHEL and Fedora, where we use non-default CPUs such as z13 on s390x, pwr9 on ppc64le, or x86-64-v2/x86-64-v3 on x86_64.

This is similar to #124597.
2025-03-21 15:48:58 +01:00
Matthias Krüger
015df66ee2
Rollup merge of #138669 - durin42:llvm-21-anon-func-unmangled, r=bjorn3
tests: accept some noise from LLVM 21 in symbols-all-mangled

I'm not entirely sure this is correct, but it doesn't feel obviously-wrong so I figured I'd just start by sending a PR rather than filing a bug and letting it linger.

``@rustbot`` label llvm-main
2025-03-21 15:48:55 +01:00
Matthias Krüger
0c594da55f
Rollup merge of #138627 - EnzymeAD:autodiff-cleanups, r=oli-obk
Autodiff cleanups

Splitting out some cleanups to reduce the size of my batching PR and simplify ``@haenoe`` 's [PR](https://github.com/rust-lang/rust/pull/138314).

r? ``@oli-obk``

Tracking:

- https://github.com/rust-lang/rust/issues/124509
2025-03-21 15:48:55 +01:00
Matthias Krüger
c354a97bd9
Rollup merge of #138570 - folkertdev:naked-function-target-feature-gate, r=Amanieu
add `naked_functions_target_feature` unstable feature

tracking issue: https://github.com/rust-lang/rust/issues/138568

tagging https://github.com/rust-lang/rust/pull/134213 https://github.com/rust-lang/rust/issues/90957

This PR puts `#[target_feature(/* ... */)]` on `#[naked]` functions behind its own feature gate, so that naked functions can be stabilized. It turns out that supporting `target_feature` on naked functions is tricky on some targets, so we're splitting it out to not block stabilization of naked functions themselves. See the tracking issue for more information and workarounds.

Note that at the time of writing, the `target_features` attribute is ignored when generating code for naked functions.

r? ``@Amanieu``
2025-03-21 15:48:52 +01:00
Matthias Krüger
4447953fdd
Rollup merge of #138751 - Jeff-A-Martin:used-with-archive-test-fuchsia, r=jieyouxu
Fix the "used_with_archive" test on Fuchsia

This change adds Fuchsia OS as a target to the cfg_attr in the pre_main_constructor external declaration. This allows the "tests/ui/attributes/used_with_archive.rs" to pass against Fuchsia.
2025-03-21 06:56:49 +01:00
Matthias Krüger
1135a63286
Rollup merge of #138724 - fmease:list-stems-bear-no-name, r=nnethercote
Check attrs: Don't try to retrieve the name of list stems

Fixes #138723.

r? nnethercote or compiler
2025-03-21 06:56:47 +01:00
bors
eda7820be5 Auto merge of #138747 - matthiaskrgr:rollup-68x44rw, r=matthiaskrgr
Rollup of 8 pull requests

Successful merges:

 - #138435 (Add support for postfix yield expressions)
 - #138685 (Use `Option<Ident>` for lowered param names.)
 - #138700 (Suggest `-Whelp` when pass `--print lints` to rustc)
 - #138727 (Do not rely on `type_var_origin` in `OrphanCheckErr::NonLocalInputType`)
 - #138729 (Clean up `FnCtxt::resolve_coroutine_interiors`)
 - #138731 (coverage: Add LLVM plumbing for expansion regions)
 - #138732 (Use `def_path_str` for def id arg in `UnsupportedOpInfo`)
 - #138735 (Remove `llvm` and `llvms` triagebot ping aliases for `icebreakers-llvm` ping group)

r? `@ghost`
`@rustbot` modify labels: rollup
2025-03-20 22:35:15 +00:00
bors
78948ac259 Auto merge of #138515 - petrochenkov:cfgtrace, r=nnethercote
expand: Leave traces when expanding `cfg_attr` attributes

Currently `cfg_trace` just disappears during expansion, but after this PR `#[cfg_attr(some tokens)]` will leave a `#[cfg_attr_trace(some tokens)]` attribute instead of itself in AST after expansion (the new attribute is built-in and inert, its inner tokens are the same as in the original attribute).
This trace attribute can then be used by lints or other diagnostics, #133823 has some examples.

Tokens in these trace attributes are set to an empty token stream, so the traces are non-existent for proc macros and cannot affect any user-observable behavior.
This is also a weakness, because if a proc macro processes some code with the trace attributes, they will be lost, so the traces are best effort rather than precise.

The next step is to do the same thing with `cfg` attributes (`#[cfg(TRUE)]` currently remains in both AST and tokens after expanding, it should be replaced with a trace instead).

The idea belongs to `@estebank.`
2025-03-20 19:24:48 +00:00
Jeff Martin
660509d717 Fix the "used_with_archive" test on Fuchsia
This change adds Fuchsia OS as a target to the cfg_attr in the
pre_main_constructor external declaration. This allows the
"tests/ui/attributes/used_with_archive.rs" to pass against Fuchsia.
2025-03-20 12:25:08 -04:00
Augie Fackler
cafd23896d tests: accept some noise from LLVM 21 in symbols-all-mangled
I'm not entirely sure this is correct, but it doesn't feel
obviously-wrong so I figured I'd just start by sending a PR rather than
filing a bug and letting it linger.

@rustbot label llvm-main
2025-03-20 11:35:59 -04:00
Matthias Krüger
55fa3f77fd
Rollup merge of #138732 - compiler-errors:did, r=jieyouxu
Use `def_path_str` for def id arg in `UnsupportedOpInfo`

We could alternatively just omit the def path from the label, but I think it's fine to keep around

Fixes #138730
2025-03-20 15:36:26 +01:00
Matthias Krüger
3e04973891
Rollup merge of #138727 - compiler-errors:ty-var-origin, r=fmease
Do not rely on `type_var_origin` in `OrphanCheckErr::NonLocalInputType`

The ordering of ty var unification means that we may end up with a root variable whose ty var origin is from another item's params.

Let's not rely on this by just unifying the infer vars with the params of the impl + resolving. It's kinda goofy but it's clearer IMO.

Fixes #132826.

r? `@fmease` or `@lcnr`
2025-03-20 15:36:20 +01:00
Matthias Krüger
28fc422f30
Rollup merge of #138700 - xizheyin:issue-138612, r=Nadrieril
Suggest `-Whelp` when pass `--print lints` to rustc

Closes #138612
2025-03-20 15:36:19 +01:00
Matthias Krüger
d752721636
Rollup merge of #138435 - eholk:prefix-yield, r=oli-obk
Add support for postfix yield expressions

We've been having a discussion about whether we want postfix yield, or want to stick with prefix yield, or have both. I figured it's easy enough to support both for now and let us play around with them while the feature is still experimental.

This PR treats `yield x` and `x.yield` as semantically equivalent. There was a suggestion to make `yield x` have a `()` type (so it only works in coroutines with `Resume = ()`. I think that'd be worth trying, either in a later PR, or before this one merges, depending on people's opinions.

#43122
2025-03-20 15:36:15 +01:00
bors
d8e44b722a Auto merge of #133889 - compiler-errors:inh-unstable, r=Nadrieril
Consider fields to be inhabited if they are unstable

Fixes #133885 with a simple heuristic

r? Nadrieril

Not totally certain if this needs T-lang approval or a crater run.
2025-03-20 14:31:34 +00:00
Michael Goulet
e6004ccb50 Use def_path_str for def id arg in UnsupportedOpInfo 2025-03-20 03:22:46 +00:00
Michael Goulet
220851cc75 Do not rely on type_var_origin in OrphanCheckErr::NonLocalInputType 2025-03-20 02:17:14 +00:00
León Orell Valerian Liehr
b5069da9df
Check attrs: Don't try to retrieve the name of list stems 2025-03-19 23:29:35 +01:00
Jesus Checa Hidalgo
20432c9eee Use explicit cpu in some asm and codegen tests.
Some tests expect to be compiled for a specific CPU or require certain
target features to be present (or absent). These tests work fine with
default CPUs but fail in downstream builds for RHEL and Fedora, where
we use non-default CPUs such as z13 on s390x, pwr9 on ppc64le, or
x86-64-v2/x86-64-v3 on x86_64.
2025-03-19 19:45:46 +01:00
lcnr
cfc78cec79 merge opaque types of nested bodies 2025-03-19 17:52:53 +01:00
Matthias Krüger
966021d00a
Rollup merge of #138613 - m-ou-se:no-more-e0773, r=jdonszelmann,petrochenkov
Remove E0773 "A builtin-macro was defined more than once."

Error E0773 "A builtin-macro was defined more than once" is triggered when using the same `#[rustc_builtin_macro(..)]` twice. However, it can only be triggered in unstable code (using a `rustc_` attribute), and there doesn't seem to be any harm in using the same implementation from `compiler/rustc_builtin_macros/…` for multiple macro definitions.

By changing the Box to an Arc in `SyntaxExtensionKind`, we can throw away the `BuiltinMacroState::{NotYetSeen, AlreadySeen}` logic, simplifying things.
2025-03-19 16:52:58 +01:00
Matthias Krüger
9ab2a0e353
Rollup merge of #138594 - oli-obk:no-select, r=lcnr
Fix next solver handling of shallow trait impl check

I'm trying to remove unnecessary direct calls to `select`, and this one seemed like a good place to start 😆

r? `@compiler-errors` or `@lcnr`
2025-03-19 16:52:57 +01:00
Matthias Krüger
c3f74bcb39
Rollup merge of #138589 - zachs18:block-label-not-supported-here-loop-body-help, r=petrochenkov
If a label is placed on the block of a loop instead of the header, suggest moving it to the header.

Fixes #138585

If a label is placed on the block of a loop instead of the header, suggest to the user moving it to the loop header instead of ~~suggesting to remove it~~ emitting a tool-only suggestion to remove it.

```rs
fn main() {
    loop 'a: { return; }
}
```

```diff
 error: block label not supported here
  --> src/main.rs:2:10
   |
 2 |     loop 'a: { return; }
   |          ^^^ not supported here
+  |
+help: if you meant to label the loop, move this label before the loop
+  |
+2 -     loop 'a: { return; }
+2 +     'a: loop { return; }
+  |
```

Questions for reviewer:

* The "desired output" in the linked issue had the main diagnostic be "misplaced loop label". Should the main diagnostic message the changed instead of leaving it as "block label not supported here"?
* Should this be `Applicability::MachineApplicable`?
2025-03-19 16:52:56 +01:00
Matthias Krüger
2ab69b898a
Rollup merge of #138001 - meithecatte:privately-uninhabited, r=Nadrieril
mir_build: consider privacy when checking for irrefutable patterns

This PR fixes #137999.

Note that, since this makes the compiler reject code that was previously accepted, it will probably need a crater run.

I include a commit that factors out a common code pattern into a helper function, purely because the fact that this was repeated all over the place was bothering me. Let me know if I should split that into a separate PR instead.
2025-03-19 16:52:54 +01:00
Matthias Krüger
ce76292014
Rollup merge of #137051 - thaliaarchi:io-optional-impls/empty, r=m-ou-se
Implement default methods for `io::Empty` and `io::Sink`

Implements default methods of `io::Read`, `io::BufRead`, and `io::Write` for `io::Empty` and `io::Sink`. These implementations are equivalent to the defaults, except in doing less unnecessary work.

`Read::read_to_string` and `BufRead::read_line` both have a redundant call to `str::from_utf8` which can't be inlined from `core` and `Write::write_all_vectored` has slicing logic which can't be simplified (See on [Compiler Explorer](https://rust.godbolt.org/z/KK6xcrWr4)). The rest are optimized to the minimal with `-C opt-level=3`, but this PR gives that benefit to unoptimized builds.

This includes an implementation of `Write::write_fmt` which just ignores the `fmt::Arguments<'_>`. This could be problematic whenever a user formatting impl is impure, but the docs do not guarantee that the args will be expanded.

Tracked in https://github.com/rust-lang/rust/issues/136756.

r? `@m-ou-se`
2025-03-19 16:52:53 +01:00
Oli Scherer
14cd467001 Fix next solver handling of shallow trait impl check 2025-03-19 14:40:14 +00:00
Oli Scherer
055d31c7a5 Demonstrate next-solver missing diagnostic 2025-03-19 14:38:23 +00:00
Mara Bos
6c865c1e14 Allow builtin macros to be used more than once.
This removes E0773 "A builtin-macro was defined more than once."
2025-03-19 14:12:47 +01:00
bors
a7fc463dd8 Auto merge of #138693 - matthiaskrgr:rollup-ejq8mwp, r=matthiaskrgr
Rollup of 10 pull requests

Successful merges:

 - #136177 (clarify BufRead::{fill_buf, consume} docs)
 - #138654 (Remove the regex dependency from coretests)
 - #138655 (rustc-dev-guide sync)
 - #138656 (Remove double nesting in post-merge workflow)
 - #138658 (CI: mirror alpine and centos images to ghcr)
 - #138659 (coverage: Don't store a body span in `FunctionCoverageInfo`)
 - #138661 (Revert: Add *_value methods to proc_macro lib)
 - #138670 (Remove existing AFIDT implementation)
 - #138674 (Various codegen_llvm cleanups)
 - #138684 (use then in docs for `fuse` to enhance readability)

r? `@ghost`
`@rustbot` modify labels: rollup
2025-03-19 12:39:34 +00:00
xizheyin
5a52b5d92a Suggest -Whelp when pass --print lints to rustc
Signed-off-by: xizheyin <xizheyin@smail.nju.edu.cn>
2025-03-19 18:48:00 +08:00
Matthias Krüger
351ba39d54
Rollup merge of #138670 - compiler-errors:remove-afidt, r=oli-obk
Remove existing AFIDT implementation

This experiment will need to be reworked differently; I don't think we'll be going with the `dyn* Future` approach that is currently implemented.

r? oli-obk

Fixes #136286
Fixes #137706
Fixes #137895

Tracking:
* #133119
2025-03-19 08:17:18 +01:00
Matthias Krüger
8b713e2cde
Rollup merge of #138661 - RalfJung:revert-rustc-dev-breakage, r=petrochenkov
Revert: Add *_value methods to proc_macro lib

This reverts https://github.com/rust-lang/rust/pull/136355. That PR caused unexpected breakage:
- the rustc-dev component can no longer be loaded by cargo, which impacts Miri and clippy and likely others
- rustc_lexer can no longer be published to crates.io, which impacts RA

See https://github.com/rust-lang/rust/issues/138647 for context.
Cc `@GuillaumeGomez` `@Amanieu`
2025-03-19 08:17:17 +01:00
Michael Goulet
0a6a0e47d2 Dont consider fields that are forced unstable due to -Zforce-unstable-if-unmarked to be uninhabited 2025-03-18 18:24:02 +00:00
Michael Goulet
f6107ca173 Consider fields to be inhabited if they are unstable 2025-03-18 18:23:36 +00:00
Michael Goulet
93b31d9b21 Remove existing AFIDT implementation 2025-03-18 17:35:26 +00:00
Ralf Jung
20d04d8a40 Revert "Rollup merge of #136355 - GuillaumeGomez:proc-macro_add_value_retrieval_methods, r=Amanieu"
This reverts commit 08dfbf49e3, reversing
changes made to 10bcdad7df.
2025-03-18 13:28:56 +01:00
Zalathar
cc8336b6c1 coverage: Don't store a body span in FunctionCoverageInfo 2025-03-18 23:18:24 +11:00
Matthias Krüger
bf98654e6c
Rollup merge of #138569 - aDotInTheVoid:reprdoc-json, r=GuillaumeGomez
rustdoc-json: Add tests for `#[repr(...)]`

Works towards #137645 and #81359

Based on #138018, but with only the test changes. CC ```@obi1kenobi```

r? ```@GuillaumeGomez```
2025-03-18 10:09:30 +01:00
bors
259fdb5212 Auto merge of #138630 - matthiaskrgr:rollup-kk1gogr, r=matthiaskrgr
Rollup of 7 pull requests

Successful merges:

 - #138384 (Move `hir::Item::ident` into `hir::ItemKind`.)
 - #138508 (Clarify "owned data" in E0515.md)
 - #138531 (Store test diffs in job summaries and improve analysis formatting)
 - #138533 (Only use `DIST_TRY_BUILD` for try jobs that were not selected explicitly)
 - #138556 (Fix ICE: attempted to remap an already remapped filename)
 - #138608 (rustc_target: Add target feature constraints for LoongArch)
 - #138619 (Flatten `if`s in `rustc_codegen_ssa`)

r? `@ghost`
`@rustbot` modify labels: rollup
2025-03-18 05:58:46 +00:00
bors
493c38ba37 Auto merge of #127173 - bjorn3:mangle_rustc_std_internal_symbol, r=wesleywiser,jieyouxu
Mangle rustc_std_internal_symbols functions

This reduces the risk of issues when using a staticlib or rust dylib compiled with a different rustc version in a rust program. Currently this will either (in the case of staticlib) cause a linker error due to duplicate symbol definitions, or (in the case of rust dylibs) cause rustc_std_internal_symbols functions to be silently overridden. As rust gets more commonly used inside the implementation of libraries consumed with a C interface (like Spidermonkey, Ruby YJIT (curently has to do partial linking of all rust code to hide all symbols not part of the C api), the Rusticl OpenCL implementation in mesa) this is becoming much more of an issue. With this PR the only symbols remaining with an unmangled name are rust_eh_personality (LLVM doesn't allow renaming it) and `__rust_no_alloc_shim_is_unstable`.

Helps mitigate https://github.com/rust-lang/rust/issues/104707

try-job: aarch64-gnu-debug
try-job: aarch64-apple
try-job: x86_64-apple-1
try-job: x86_64-mingw-1
try-job: i686-mingw-1
try-job: x86_64-msvc-1
try-job: i686-msvc-1
try-job: test-various
try-job: armhf-gnu
2025-03-17 22:16:22 +00:00
Matthias Krüger
cd4dfd77fa
Rollup merge of #138556 - charmitro:already-remapped-filename, r=GuillaumeGomez,Urgau
Fix ICE: attempted to remap an already remapped filename

This commit fixes an internal compiler error (ICE) that occurs when
rustdoc attempts to process macros with a remapped filename. The issue
arose during macro expansion when the `--remap-path-prefix` option was
used.

Instead of passing remapped filenames through, which would trigger the
"attempted to remap an already remapped filename" panic, we now
extract the original local path from remapped filenames before
processing them.

A test case has been added to verify this behavior.

Fixes #138520
2025-03-17 22:49:07 +01:00
Manuel Drehwald
f9d0a14639 resolve repeated attribute fixme 2025-03-17 17:06:26 -04:00
Manuel Drehwald
03ece26b79 update tests 2025-03-17 16:21:45 -04:00
bors
43a2e9d2c7 Auto merge of #138611 - matthiaskrgr:rollup-hmjbqva, r=matthiaskrgr
Rollup of 7 pull requests

Successful merges:

 - #133870 (Stabilize `asm_goto` feature gate)
 - #137449 (Denote `ControlFlow` as `#[must_use]`)
 - #137465 (mir_build: Avoid some useless work when visiting "primary" bindings)
 - #138349 (Emit function declarations for functions with `#[linkage="extern_weak"]`)
 - #138412 (Install licenses into `share/doc/rust/licenses`)
 - #138577 (rustdoc-json: Don't also include `#[deprecated]` in `Item::attrs`)
 - #138588 (Avoid double lowering of idents)

Failed merges:

 - #138321 ([bootstrap] Distribute split debuginfo if present)

r? `@ghost`
`@rustbot` modify labels: rollup
2025-03-17 19:04:14 +00:00
bors
8279176ccd Auto merge of #137081 - Shourya742:2025-02-15-change-config.toml-to-bootstrap.toml, r=onur-ozkan,jieyouxu,kobzol
change config.toml to bootstrap.toml

Currently, both Bootstrap and Cargo uses same name as their configuration file, which can be confusing. This PR is based on a discussion to rename `config.toml` to `bootstrap.toml` for Bootstrap. Closes: https://github.com/rust-lang/rust/issues/126875.

I have split the PR into atomic commits to make it easier to review. Once the changes are finalized, I will squash them. I am particularly concerned about the changes made to modules that are not part of Bootstrap. How should we handle those changes? Should we ping the respective maintainers?
2025-03-17 15:51:28 +00:00
Matthias Krüger
b15e663dbd
Rollup merge of #138577 - aDotInTheVoid:deprecate-deprecations, r=GuillaumeGomez
rustdoc-json: Don't also include `#[deprecated]` in `Item::attrs`

Closes #138378

Not sure if this should bump `FORMAT_VERSION` or not. CC `@Enselic` `@LukeMathWalker` `@obi1kenobi`

r? `@GuillaumeGomez,` best reviewed commit-by-commit
2025-03-17 16:34:51 +01:00
Matthias Krüger
8f5c09b37c
Rollup merge of #138349 - 1c3t3a:external-weak-cfi, r=rcvalle
Emit function declarations for functions with `#[linkage="extern_weak"]`

Currently, when declaring an extern weak function in Rust, we use the following syntax:
```rust
unsafe extern "C" {
   #[linkage = "extern_weak"]
   static FOO: Option<unsafe extern "C" fn() -> ()>;
}
```
This allows runtime-checking the extern weak symbol through the Option.

When emitting LLVM-IR, the Rust compiler currently emits this static as an i8, and a pointer that is initialized with the value of the global i8 and represents the nullabilty e.g.
```
`@FOO` = extern_weak global i8
`@_rust_extern_with_linkage_FOO` = internal global ptr `@FOO`
```

This approach does not work well with CFI, where we need to attach CFI metadata to a concrete function declaration, which was pointed out in https://github.com/rust-lang/rust/issues/115199.

This change switches to emitting a proper function declaration instead of a global i8. This allows CFI to work for extern_weak functions. Example:
```
`@_rust_extern_with_linkage_FOO` = internal global ptr `@FOO`
...
declare !type !61 !type !62 !type !63 !type !64 extern_weak void `@FOO(double)` unnamed_addr #6
```

We keep initializing the Rust internal symbol with the function declaration, which preserves the correct behavior for runtime checking the Option.

r? `@rcvalle`

cc `@jakos-sec`

try-job: test-various
2025-03-17 16:34:50 +01:00
Matthias Krüger
fd4ad33242
Rollup merge of #137465 - Zalathar:visit-primary, r=oli-obk
mir_build: Avoid some useless work when visiting "primary" bindings

While looking over `visit_primary_bindings`, I noticed that it does a bunch of extra work to build up a collection of “user-type projections”, even though 2/3 of its call sites don't even use them. Those callers can get the same result via `thir::Pat::walk_always`.

(And it turns out that doing so also avoids creating some redundant user-type entries in MIR for some binding constructs.)

I also noticed that even when the user-type projections *are* used, the process of building them ends up eagerly cloning some nested vectors at every recursion step, even in cases where they won't be used because the current subpattern has no bindings. To avoid this, the visit method now assembles a linked list on the stack containing the information that *would* be needed to create projections, and only creates the concrete projections as needed when a primary binding is encountered.

Some relevant prior PRs:
- #55274
- 0bfe184b1a in #55937

---

There should be no user-visible change in compiler output.
2025-03-17 16:34:48 +01:00