[`compiletest`-related cleanups 1/7] Cleanup `is_rustdoc` logic and remove a useless path join in rustdoc-json runtest logic
Reference for overall changes: https://github.com/rust-lang/rust/pull/136437
Part **1** of **7** of the *`compiletest`-related cleanups* PR series.
### Summary
- Don't match on path when we already have test suite names.
- Remove a useless path join.
r? bootstrap (or compiler)
LTA: Actually check where-clauses for well-formedness at the def site
All of the added tests used to wrongfully pass.
r? oli-obk or types/compiler or reassign
Remove a footgun-y feature / relic of the past from the compiletest DSL
The compiletest DSL still features a historical remnant from the time when its directives were merely prefixed with `//` instead of `//`@`` when unknown directive names weren't rejected since they could just as well be part of prose:
As an "optimization", it stops looking for directives once it stumbles upon a line which starts with either `fn` or `mod`. This is super footgun-y as it obviously leads to any seeming compiletest directives below `fn` and `mod` items getting completely ignored.
See #136403 for a practical example. As well the assembly test updated in this PR.
~~Blocked on #136403.~~ (merged)
Target modifiers (special marked options) are recorded in metainfo
Target modifiers (special marked options) are recorded in metainfo and compared to be equal in different linked crates.
PR for this RFC: https://github.com/rust-lang/rfcs/pull/3716
Option may be marked as `TARGET_MODIFIER`, example: `regparm: Option<u32> = (None, parse_opt_number, [TRACKED TARGET_MODIFIER]`.
If an TARGET_MODIFIER-marked option has non-default value, it will be recorded in crate metainfo as a `Vec<TargetModifier>`:
```
pub struct TargetModifier {
pub opt: OptionsTargetModifiers,
pub value_name: String,
}
```
OptionsTargetModifiers is a macro-generated enum.
Option value code (for comparison) is generated using `Debug` trait.
Error example:
```
error: mixing `-Zregparm` will cause an ABI mismatch in crate `incompatible_regparm`
--> $DIR/incompatible_regparm.rs:10:1
|
LL | #![crate_type = "lib"]
| ^
|
= help: the `-Zregparm` flag modifies the ABI so Rust crates compiled with different values of this flag cannot be used together safely
= note: `-Zregparm=1` in this crate is incompatible with `-Zregparm=2` in dependency `wrong_regparm`
= help: set `-Zregparm=2` in this crate or `-Zregparm=1` in `wrong_regparm`
= help: if you are sure this will not cause problems, use `-Cunsafe-allow-abi-mismatch=regparm` to silence this error
error: aborting due to 1 previous error
```
`-Cunsafe-allow-abi-mismatch=regparm,reg-struct-return` to disable list of flags.
Explain why we retroactively change a static initializer to have a different type
I keep getting confused about it and in turn confused `@GuillaumeGomez` while trying to explain it badly
Shorten error message for callable with wrong return type
```
error: expected `{closure@...}` to return `Ret`, but it returns `Other`
```
instead of
```
error: expected `{closure@...}` to be a closure that returns `Ret`, but it returns `Other`
```
Fix malformed error annotations in a UI test
The compiletest DSL still features a historical remnant from the time when its directives were merely prefixed with `//` instead of `//`@`` when unknown directive names weren't rejected since they could just as well be part of prose:
As an "optimization", it stops looking for directives once it stumbles upon a line which starts with either `fn` or `mod`. This allowed a malformed error annotation of the form `//`@[…]~^^^`` to go undetected & unexercised (as it's placed below `fn main() {`).
Obviously a character other than ``@`` would've mangled the error annotation, too (but it might've caught the reviewer's eye). I specifically found this file because I ran `rg '^(fn|mod)[\s\S]*?//`@'` tests/ui --multiline -trust` to check how footgun-y that "special feature" of compiletest is.
CompileTest: Add Directives to Ignore `arm-unknown-*` Targets
In #134626, I want to ignore `arm-unknown-*` targets because the LLVM IR for those looks very different compared to other targets: https://rust.godbolt.org/z/ssYMhdv4x.
I can use `ignore-arm` but, I think, it would exclude large number of Apple devices.
So this PR adds a few directives to ignore `arm-unknown-*` targets specifically.
Test validity of pattern types
r? `@RalfJung`
pulled out of #136006 so we don't have to rely on libcore types excercising this code path
There's nothing to fix. `rustc_layout_scalar_valid_range_start` structs just failed their validation on their value instead of their fields' value, causing a diff where moving to pattern types adds an additional `.0` field access to the validation error
This is necessary to unblock rust-lang/rust#122408. The documentation for these is available [here](https://developer.apple.com/documentation/os/os_sync_wait_on_address?language=objc).
Because the futex wait operations (`os_sync_wait_on_address` et al.) return the number of remaining waiters after returning, this required some changes to the common futex infrastructure, which I've changed to take a callback instead of precalculating the return values.
rustc_allowed_through_unstable_modules: require deprecation message
This changes the `#[rustc_allowed_through_unstable_modules]` attribute so that a deprecation message (ideally directing people towards the stable path) is required.
Convert two `rustc_middle::lint` functions to `Span` methods.
`rustc_middle` is a huge crate and it's always good to move stuff out of it. There are lots of similar methods already on `Span`, so these two functions, `in_external_macro` and `is_from_async_await`, fit right in. The diff is big because `in_external_macro` is used a lot by clippy lints.
r? ``@Noratrieb``
Highlight clarifying information in "expected/found" error
When the expected and found types have the same textual representation, we add clarifying in parentheses. We now visually highlight it in the output.
Detect a corner case where the clarifying information would be the same for both types and skip it, as it doesn't add anything useful.

diagnostics: fix borrowck suggestions for if/while let conditionals
This code detects the case where one of the borrows is inside the let init expr while the other end is not. If that happens, we don't want to suggest adding a semicolon, because it won't work.
Fixes#133941
Clean up MonoItem::instantiation_mode
More progress on cleaning up and documenting instantiation mode selection.
This should have no behavior changes at all, it just rearranges the code inside `MonoItem::instantiation_mode` to a more logical flow and I've tried to explain every choice the implementation is making.