Commit Graph

42996 Commits

Author SHA1 Message Date
Matthias Krüger 3b36879203 Rollup merge of #135794 - estebank:non-exhaustive-dfv-ctor, r=jieyouxu
Detect missing fields with default values and suggest `..`

When a struct ctor use has missing fields, if all those missing fields have defaults, suggest `..`:

```
error[E0063]: missing fields `field1` and `field2` in initializer of `S`
  --> $DIR/non-exhaustive-ctor.rs:16:13
   |
LL |     let _ = S { field: () };
   |             ^ missing `field1` and `field2`
   |
help: all remaining fields have default values, you can use those values with `..`
   |
LL |     let _ = S { field: (), .. };
   |                          ++++
```
2025-01-22 20:37:26 +01:00
Matthias Krüger 5fab5429c4 Rollup merge of #135596 - compiler-errors:stack, r=oli-obk
Properly note when query stack is being cut off

cc #70953

also, i'm not certain whether we should even limit this at all. i don't see the problem with printing the full query stack, apparently it was limited b/c we used to ICE? but we're already printing the full stack to disk since #108714.

r? oli-obk
2025-01-22 20:37:25 +01:00
Matthias Krüger b4266b0bcd Rollup merge of #135557 - estebank:wtf8, r=fee1-dead
Point at invalid utf-8 span on user's source code

```
error: couldn't read `$DIR/not-utf8-bin-file.rs`: stream did not contain valid UTF-8
  --> $DIR/not-utf8-2.rs:6:5
   |
LL |     include!("not-utf8-bin-file.rs");
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
note: byte `193` is not valid utf-8
  --> $DIR/not-utf8-bin-file.rs:2:14
   |
LL |     let _ = "�|�␂!5�cc␕␂��";
   |              ^
   = note: this error originates in the macro `include` (in Nightly builds, run with -Z macro-backtrace for more info)
```

When we attempt to load a Rust source code file, if there is a OS file failure we try reading the file as bytes. If that succeeds we try to turn it into UTF-8. If *that* fails, we provide additional context about *where* the file has the first invalid UTF-8 character.

Fix #76869.
2025-01-22 20:37:24 +01:00
Matthias Krüger f875983035 Rollup merge of #135409 - Shunpoco:issue-133117-ICE-never-false-edge-start-block, r=Nadrieril
Fix ICE-133117: multiple never-pattern arm doesn't have false_edge_start_block

Fixes #133117 , and close fixes #133063 , fixes #130779

In order to fix ICE-133117, at first I needed to tackle to ICE-133063 (this fixed 130779 as well).

### ICE-133063 and ICE-130779
This ICE is caused by those steps:
1. An arm has or-pattern, and all of the sub-candidates are never-pattern
2. In that case, all sub-candidates are removed in remove_never_subcandidates(). So the arm (candidate) has no sub-candidate.
3. In the current implementation, if there is no sub-candidate, the function assigns `pre_binding_block` into the candidate ([here](https://github.com/rust-lang/rust/blob/master/compiler/rustc_mir_build/src/builder/matches/mod.rs#L2002-L2004)). However, otherwise_block should be assigned to the candidate as well, because the otherwise_block is unwrapped in multiple place (like in lower_match_tree()). As a result, it causes the panic.

I simply added the same block as pre_binding_block into otherwise_block, but I'm wondering if there is a better block to assign to otherwise_block (is it ok to assign the same block into pre_binding and otherwise?)

### ICE-133117
This is caused by those steps:
1. There are two arms, both are or-pattern and each has one match-pair (in the test code, both are `(!|!)`), and the second arm has a guard.
2. In match_candidate() for the first arm, it expands the second arm’s sub-candidates as well ([here](https://github.com/rust-lang/rust/blob/master/compiler/rustc_mir_build/src/builder/matches/mod.rs#L1800-L1805)). As a result, the root candidate of the second arm is not evaluated/modified in match_candidate(). So a false_edge_start_block is not assigned to the candidate.
3. merge_trivial_subcandidates() is called against the candidate for the second arm. It just returns immediately because the candidate has a guard. So a flase_edge_start_block is not assigned to the candidate also in this function.
4. remove_never_subcandidates() is called against the candidate. Since all sub-candidates are never-pattern. they are removed.
5. In lower_match_tree(), since there is no sub-candidate for the candidate, the candidate itself is evaluated in visit_leave_rev ([here](https://github.com/rust-lang/rust/blob/master/compiler/rustc_mir_build/src/builder/matches/mod.rs#L1532)). Because the candidate has no false_edge_start_block, it causes the panic.

So I modified the order of if blocks in merge_trivial_subcandidates() to assign a false_edge_start_block if the candidate doesn't have.
2025-01-22 20:37:24 +01:00
Matthias Krüger 9206ba535c Rollup merge of #132983 - Anthony-Eid:dangling-pointers-lint, r=Urgau
Edit dangling pointers

Closes: #132283
2025-01-22 20:37:23 +01:00
bors dee7d0e730 Auto merge of #134478 - compiler-errors:attr-span, r=oli-obk
Properly record metavar spans for other expansions other than TT

This properly records metavar spans for nonterminals other than tokentree. This means that we operations like `span.to(other_span)` work correctly for macros. As you can see, other diagnostics involving metavars have improved as a result.

Fixes #132908
Alternative to #133270

cc `@ehuss`
cc `@petrochenkov`
2025-01-22 14:46:41 +00:00
Anthony Eid 12214db74b Update lint tests with new dangling pointers message 2025-01-22 00:00:31 -05:00
bors b2728d5426 Auto merge of #135674 - scottmcm:assume-better, r=estebank
Update our range `assume`s to the format that LLVM prefers

I found out in https://github.com/llvm/llvm-project/issues/123278#issuecomment-2597440158 that the way I started emitting the `assume`s in #109993 was suboptimal, and as seen in that LLVM issue the way we're doing it -- with two `assume`s sometimes -- can at times lead to CVP/SCCP not realize what's happening because one of them turns into a `ne` instead of conveying a range.

So this updates how it's emitted from
```
assume( x >= LOW );
assume( x <= HIGH );
```
or
```
// (for ranges that wrap the range)
assume( (x <= LOW) | (x >= HIGH) );
```
to
```
assume( (x - LOW) <= (HIGH - LOW) );
```
so that we don't need multiple `icmp`s nor multiple `assume`s for a single value, and both wrappping and non-wrapping ranges emit the same shape.

(And we don't bother emitting the subtraction if `LOW` is zero, since that's trivial for us to check too.)
2025-01-22 04:18:30 +00:00
Shunpoco 7275bdf6ec modify comment
Signed-off-by: Shunpoco <tkngsnsk313320@gmail.com>
2025-01-22 02:42:11 +00:00
Shunpoco 481ed2d931 address review: modify matches/mod.rs
The candidate shouldn't have false_edge_start_block if it has sub candidates.
In remove_never_subcandidates(), the false_edge_start_block from the first sub candidte is assigned to a value and the value is later used if all sub candidates are removed and candidate doesn't have false_edge_start_block.
In merge_trivial_subcandidates, I leave the if block which assign a false_edge_start_block into the candidate as before I put this commit since compile panics.

Signed-off-by: Shunpoco <tkngsnsk313320@gmail.com>
2025-01-22 01:55:58 +00:00
bors c234b839d1 Auto merge of #135848 - matthiaskrgr:rollup-sftciqm, r=matthiaskrgr
Rollup of 8 pull requests

Successful merges:

 - #132232 (CI: build FreeBSD artifacts on FreeBSD 13.4)
 - #135706 (Move `supertrait_def_ids` into the elaborate module like all other fns)
 - #135750 (Add an example of using `carrying_mul_add` to write wider multiplication)
 - #135793 (Ignore `mermaid.min.js`)
 - #135810 (Add Kobzol on vacation)
 - #135821 (fix OsString::from_encoded_bytes_unchecked description)
 - #135824 (tests: delete `cat-and-grep-sanity-check`)
 - #135833 (Add fixme and test for issue #135289)

Failed merges:

 - #135816 (Use `structurally_normalize` instead of manual `normalizes-to` goals in alias relate errors)

r? `@ghost`
`@rustbot` modify labels: rollup
2025-01-22 01:13:23 +00:00
Esteban Küber 57dd42d613 Point at invalid utf-8 span on user's source code
```
error: couldn't read `$DIR/not-utf8-bin-file.rs`: stream did not contain valid UTF-8
  --> $DIR/not-utf8-2.rs:6:5
   |
LL |     include!("not-utf8-bin-file.rs");
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
note: `[193]` is not valid utf-8
  --> $DIR/not-utf8-bin-file.rs:2:14
   |
LL |     let _ = "�|�␂!5�cc␕␂��";
   |              ^
   = note: this error originates in the macro `include` (in Nightly builds, run with -Z macro-backtrace for more info)
```

When we attempt to load a Rust source code file, if there is a OS file failure we try reading the file as bytes. If that succeeds we try to turn it into UTF-8. If *that* fails, we provide additional context about *where* the file has the first invalid UTF-8 character.

Fix #76869.
2025-01-22 00:52:27 +00:00
Matthias Krüger a7408c458b Rollup merge of #135833 - lqd:add-ice-test, r=compiler-errors
Add fixme and test for issue #135289

This PR:
- adds a test minimizing issue #135289 for PR #135310
- adds a fixme about the suboptimal fix for the ICE

I've verified the test indeed ICEs with 3f2f695d68 reverted.

r? `@estebank`
2025-01-21 23:30:23 +01:00
Matthias Krüger 4af3ff8cd1 Rollup merge of #135706 - compiler-errors:elaborate, r=lcnr
Move `supertrait_def_ids` into the elaborate module like all other fns

It's strange that this is the only elaborate-like fn on tcx.

r? lcnr
2025-01-21 23:30:18 +01:00
bors a24bdc60ce Auto merge of #135487 - klensy:windows-0.59, r=Mark-Simulacrum
bump compiler and tools to windows 0.59, bootstrap to 0.57

This bumps compiler and tools to windows 0.59 (temporary dupes version, as `sysinfo` still depend on <= 0.57).
Bootstrap bumps only to 0.57 (the same sysinfo dep).

This additionally resolves my comment https://github.com/rust-lang/rust/pull/130874#issuecomment-2393562071

Will work on it in follow up pr: There still some sus imports for `rustc_driver.dll` like ws2_32 or RoOriginateErrorW, but i will look at them later.
2025-01-21 22:29:46 +00:00
Esteban Küber 922e6bb2d4 Detect missing fields with default values and suggest ..
When a struct definition has default field values, and the use struct ctor has missing field, if all those missing fields have defaults suggest `..`:

```
error[E0063]: missing fields `field1` and `field2` in initializer of `S`
  --> $DIR/non-exhaustive-ctor.rs:16:13
   |
LL |     let _ = S { field: () };
   |             ^ missing `field1` and `field2`
   |
help: all remaining fields have defaults, use `..`
   |
LL |     let _ = S { field: (), .. };
   |                          ++++
```
2025-01-21 21:26:37 +00:00
bors ed43cbcb88 Auto merge of #134299 - RalfJung:remove-start, r=compiler-errors
remove support for the (unstable) #[start] attribute

As explained by `@Noratrieb:`
`#[start]` should be deleted. It's nothing but an accidentally leaked implementation detail that's a not very useful mix between "portable" entrypoint logic and bad abstraction.

I think the way the stable user-facing entrypoint should work (and works today on stable) is pretty simple:
- `std`-using cross-platform programs should use `fn main()`. the compiler, together with `std`, will then ensure that code ends up at `main` (by having a platform-specific entrypoint that gets directed through `lang_start` in `std` to `main` - but that's just an implementation detail)
- `no_std` platform-specific programs should use `#![no_main]` and define their own platform-specific entrypoint symbol with `#[no_mangle]`, like `main`, `_start`, `WinMain` or `my_embedded_platform_wants_to_start_here`. most of them only support a single platform anyways, and need cfg for the different platform's ways of passing arguments or other things *anyways*

`#[start]` is in a super weird position of being neither of those two. It tries to pretend that it's cross-platform, but its signature is  a total lie. Those arguments are just stubbed out to zero on ~~Windows~~ wasm, for example. It also only handles the platform-specific entrypoints for a few platforms that are supported by `std`, like Windows or Unix-likes. `my_embedded_platform_wants_to_start_here` can't use it, and neither could a libc-less Linux program.
So we have an attribute that only works in some cases anyways, that has a signature that's a total lie (and a signature that, as I might want to add, has changed recently, and that I definitely would not be comfortable giving *any* stability guarantees on), and where there's a pretty easy way to get things working without it in the first place.

Note that this feature has **not** been RFCed in the first place.

*This comment was posted [in May](https://github.com/rust-lang/rust/issues/29633#issuecomment-2088596042) and so far nobody spoke up in that issue with a usecase that would require keeping the attribute.*

Closes https://github.com/rust-lang/rust/issues/29633

try-job: x86_64-gnu-nopt
try-job: x86_64-msvc-1
try-job: x86_64-msvc-2
try-job: test-various
2025-01-21 19:46:20 +00:00
Michael Goulet 45929a8f46 Move supertrait_def_ids into the elaborate module like all other fns 2025-01-21 17:36:57 +00:00
Rémy Rakic 9bad0daef6 add fixme in typoed const pattern lint 2025-01-21 16:18:34 +00:00
Ralf Jung 56c90dc31e remove support for the #[start] attribute 2025-01-21 06:59:15 -07:00
klensy 84ce2e129a bumpt compiler and tools to windows 0.59 2025-01-21 16:48:44 +03:00
bors cd805f09ff Auto merge of #133830 - compiler-errors:span-key, r=lcnr
Rework dyn trait lowering to stop being so intertwined with trait alias expansion

This PR reworks the trait object lowering code to stop handling trait aliases so funky, and removes the `TraitAliasExpander` in favor of a much simpler design. This refactoring is important for making the code that I'm writing in https://github.com/rust-lang/rust/pull/133397 understandable and easy to maintain, so the diagnostics regressions are IMO inevitable.

In the old trait object lowering code, we used to be a bit sloppy with the lists of traits in their unexpanded and expanded forms. This PR largely rewrites this logic to expand the trait aliases *once* and handle them more responsibly throughout afterwards.

Please review this with whitespace disabled.

r? lcnr
2025-01-21 12:33:33 +00:00
Oli Scherer dfa4c01b2e Treat undef bytes as equal to any other byte 2025-01-21 08:27:21 +00:00
Oli Scherer 8876cf7181 Also generate undef scalars and scalar pairs 2025-01-21 08:22:15 +00:00
Matthias Krüger 67b609a919 Rollup merge of #135776 - bjorn3:sync_cg_clif-2025-01-20, r=bjorn3
Subtree sync for rustc_codegen_cranelift

Nothing too exciting this time, but this includes a fix for a linker hang on Windows: https://github.com/rust-lang/rustc_codegen_cranelift/pull/1554

r? ``@ghost``

``@rustbot`` label +A-codegen +A-cranelift +T-compiler
2025-01-20 20:58:38 +01:00
Matthias Krüger 0d5b8138bb Rollup merge of #135333 - vayunbiyani:test-environment, r=RalfJung
Partial progress on #132735: Replace extern "rust-intrinsic" with #[rustc_intrinsic] across the codebase

Part of #132735: Replace `extern "rust-intrinsic"` with `#[rustc_intrinsic]` macro

- Updated all instances of `extern "rust-intrinsic"` to use the `#[rustc_intrinsic]` macro.
- Skipped `.md` files and test files to avoid unnecessary changes.
2025-01-20 20:58:35 +01:00
Matthias Krüger c8c5fa4893 Rollup merge of #135330 - bjorn3:respect_sysroot_in_version_printing, r=lqd
Respect --sysroot for rustc -vV and -Cpasses=list

This is necessary when the specified codegen backend is in a custom sysroot.

Fixes https://github.com/rust-lang/rust/issues/135165
2025-01-20 20:58:35 +01:00
bors 9f4d9dc102 Auto merge of #135769 - jieyouxu:rollup-3h384pz, r=jieyouxu
Rollup of 5 pull requests

Successful merges:

 - #135433 (Add Profile Override for Non-Git Sources)
 - #135626 (doc: Point to methods on `Command` as alternatives to `set/remove_var`)
 - #135658 (Do not include GCC source code in source tarballs)
 - #135676 (rustc_resolve: use structured fields in traces)
 - #135762 (Correct counting to four in cell module docs)

r? `@ghost`
`@rustbot` modify labels: rollup
2025-01-20 17:07:30 +00:00
bjorn3 056a9cebe9 Respect --target in get_backend_from_raw_matches 2025-01-20 15:47:26 +00:00
bjorn3 d740a3f06a Merge commit '728bc27f32c05ac8a9b5eb33fd101e479072984f' into sync_cg_clif-2025-01-20 2025-01-20 15:30:04 +00:00
bors 6a64e3b897 Auto merge of #135643 - khuey:135332, r=jieyouxu
When LLVM's location discriminator value limit is exceeded, emit locations with dummy spans instead of dropping them entirely

Dropping them fails `-Zverify-llvm-ir`.

Fixes #135332.

r? `@jieyouxu`
2025-01-20 14:16:22 +00:00
vayunbiyani c79fc90e9a Updated several files to use rust intrinsic macros instead of the legacy extern "rust-intrinsic" blocks 2025-01-20 09:15:23 -05:00
许杰友 Jieyou Xu (Joe) 3e26673b29 Rollup merge of #135676 - yotamofek:resolve-cleanups, r=BoxyUwU
rustc_resolve: use structured fields in traces

I think this crate was written before `tracing` was adopted, and was manually writing fields into trace logs instead of using structured fields.

I kept function names in the trace messages even though I added `#[instrument]` invocations so that the events will be in named spans, wasn't sure if spans are always printed.
2025-01-20 21:45:06 +08:00
bors b5741a36a8 Auto merge of #135754 - jieyouxu:rollup-j4q1hpr, r=jieyouxu
Rollup of 7 pull requests

Successful merges:

 - #135542 (Add the concrete syntax for precise capturing to 1.82 release notes.)
 - #135700 (Emit single privacy error for struct literal with multiple private fields and add test for `default_field_values` privacy)
 - #135722 (make it possible to use ci-rustc on tarball sources)
 - #135729 (Add debug assertions to compiler profile)
 - #135736 (rustdoc: Fix flaky doctest test)
 - #135738 (Replace usages of `map_or(bool, ...)` with `is_{some_and|none_or|ok_and}`)
 - #135747 (Rename FileName::QuoteExpansion to CfgSpec)

r? `@ghost`
`@rustbot` modify labels: rollup
2025-01-20 10:35:43 +00:00
Yotam Ofek 539b4d8555 rustc_resolve: use structured fields in traces 2025-01-20 07:20:02 +00:00
许杰友 Jieyou Xu (Joe) 3f2f695d68 Rollup merge of #135310 - estebank:issue-135289, r=Nadrieril
Always force non-trimming of path in `unreachable_patterns` lint

Creating a "trimmed DefID path" when no error is being emitted is an ICE (on purpose). If we create a trimmed path for a lint that is then silenced before being emitted causes a known ICE. This side-steps the issue by always using `with_no_trimmed_path!`.

This was verified to fix https://github.com/quinn-rs/quinn/, but couldn't write a repro case for the test suite.

Fix #135289.
2025-01-20 12:38:31 +08:00
许杰友 Jieyou Xu (Joe) 1419f79acf Rollup merge of #135237 - dianne:match-2024-cleanup, r=Nadrieril
Match Ergonomics 2024: document and reorganize the currently-implemented feature gates

The hope here is to make it easier to adjust, understand, and test the experimental pattern typing rules implemented in the compiler. This PR doesn't (or at isn't intended to) change any behavior or add any new tests; I'll be handling that later. I've also included some reasoning/commentary on the more involved changes in the commit messages.

Relevant tracking issue: #123076

r? `@Nadrieril`
2025-01-20 12:38:31 +08:00
许杰友 Jieyou Xu (Joe) be8f1f9949 Rollup merge of #134276 - RalfJung:destabilize-custom-inner-attr, r=SparrowLii
fully de-stabilize all custom inner attributes

`#![test]` and `#![rustfmt::skip]` were accidentally accepted in more places than they should. These have been marked as soft-unstable since forever (https://github.com/rust-lang/rust/pull/82399) and shown in future-compat reports since Rust 1.77 (https://github.com/rust-lang/rust/pull/116274).

Cc `@rust-lang/lang` `@petrochenkov`
2025-01-20 12:38:30 +08:00
许杰友 Jieyou Xu (Joe) 82a239c798 Rollup merge of #135747 - ehuss:filename-quote, r=SparrowLii
Rename FileName::QuoteExpansion to CfgSpec

I believe this variant name was used incorrectly. The timeline is roughly:

* `FileName::cfg_spec_source_code` was added in https://github.com/rust-lang/rust/pull/54517. However, it used `FileName::Quote` instead of `FileName::CfgSpec` which I believe was a mistake.
* Quote stuff was removed in https://github.com/rust-lang/rust/pull/51285, but did not remove `FileName::Quote`.
* `FileName::CfgSpec` was removed in https://github.com/rust-lang/rust/pull/116474 because it was unused.

This restores it so that the `--cfg` variant uses a name that makes more sense with how it is used, and restores what I think is the original intent.
2025-01-20 12:37:56 +08:00
许杰友 Jieyou Xu (Joe) f3f21ae6a4 Rollup merge of #135738 - yotamofek:map_or_true-compiler, r=compiler-errors
Replace usages of `map_or(bool, ...)` with `is_{some_and|none_or|ok_and}`

Split out from #135732 according to https://github.com/rust-lang/rust/pull/135732?pullrequestreview-2561072330 ,
same thing but just for the compiler:

> The usage of `map_or(bool, ...)` is really hard to understand IMHO.
> This PR simply uses clippy (with `--fix`) to replace that with `is_{some_and|none_or|ok_and}`.
> (no manual modifications were made, just machine applicable clippy fixes and then fmt)

r? ``@compiler-errors``
2025-01-20 12:37:56 +08:00
许杰友 Jieyou Xu (Joe) 6db2d1aae5 Rollup merge of #135700 - estebank:priv-field-dfv, r=wesleywiser
Emit single privacy error for struct literal with multiple private fields and add test for `default_field_values` privacy

Add test ensuring that struct with default field values is not constructable if the fields are not accessible.

Collect all unreachable fields in a single struct literal struct and emit a single error, instead of one error per private field.

```
error[E0451]: fields `beta` and `gamma` of struct `Alpha` are private
  --> $DIR/visibility.rs:18:13
   |
LL |     let _x = Alpha {
   |              ----- in this type
LL |         beta: 0,
   |         ^^^^^^^ private field
LL |         ..
   |         ^^ field `gamma` is private
```
2025-01-20 12:37:54 +08:00
dianne 0263772bac elaborate/clarify the comments on InheritedRefMatchRule's variants 2025-01-19 16:03:15 -08:00
dianne bfa0e1e0ad Add debug-assertions for assumptions about enabled typing rules 2025-01-19 15:32:37 -08:00
dianne 48e023a56f Add comments explaining inherited references
This adds explanation of inherited references and how they relate to the default binding mode.

Co-authored-by: Nadrieril <Nadrieril@users.noreply.github.com>
2025-01-19 15:26:14 -08:00
Eric Huss cee45632e8 Rename FileName::QuoteExpansion to CfgSpec
I believe this variant name was used incorrectly. The timeline is roughly:

* `FileName::cfg_spec_source_code` was added in
  https://github.com/rust-lang/rust/pull/54517. However, it used
  `FileName::Quote` instead of `FileName::CfgSpec` which I believe was a
  mistake.
* Quote stuff was removed in
  https://github.com/rust-lang/rust/pull/51285, but did not remove
  `FileName::Quote`.
* `FileName::CfgSpec` was removed in
  https://github.com/rust-lang/rust/pull/116474 because it was unused.

This restores it so that the `--cfg` variant uses a name that makes more
sense with how it is used, and restores what I think is the original
intent.
2025-01-19 14:18:46 -08:00
Yotam Ofek 1951d86a35 Manual cleanup of some is_{or_none|some_and} usages 2025-01-19 20:50:43 +00:00
Yotam Ofek 264fa0fc54 Run clippy --fix for unnecessary_map_or lint 2025-01-19 19:15:00 +00:00
Ralf Jung 5bd20b0608 fully de-stabilize all custom inner attributes 2025-01-19 08:53:02 -07:00
Kyle Huey 45ef92731b When LLVM's location discriminator value limit is exceeded, emit locations with dummy spans instead of dropping them entirely
Revert most of #133194 (except the test and the comment fixes). Then refix
not emitting locations at all when the correct location discriminator value
exceeds LLVM's capacity.
2025-01-19 07:17:33 -08:00
Guillaume Gomez dcc71c0637 Rollup merge of #135716 - Zalathar:usage-no-args, r=lqd
Don't skip argument parsing when running `rustc` with no arguments

Setting up the argument parser to parse no arguments is a tiny bit of wasted work, but avoids an otherwise-unnecessary special case, in a scenario (printing a help message and quitting) where perf at this scale really doesn't matter anyway.

In particular, this lets us avoid having to deal with multiple different APIs to determine whether the compiler is nightly or not.

---

This special-case handling for rustc with no arguments is very very old (long predating 1.0), and used to be much simpler, without any need to set up boolean values to handle various conditional cases. So I don't think it was ever explicitly decided that having this special case was worth the extra complexity; it just started out simple and accumulated complexity over time.
2025-01-19 11:48:17 +01:00