It can be useful to do some computation in `assert!` format arguments, in order to get better error messages. For example:
```rust
assert!(
some_condition,
"The state is invalid. Details: {}",
expensive_call_to_get_debugging_info(),
);
```
It seems like `assert!` only evaluates the format arguments if the assertion fails, which is useful but doesn't appear to be documented anywhere. This PR documents the behavior and adds some tests.
Ensures `make` tests run under /bin/dash (if available), like CI, and fixes a Makefile
Note: This cherrypicks #81688 (`@pnkfelix)`
Updates `tools.mk` to explicitly require `SHELL := /bin/dash`, since CI uses `dash` but other environments (including developer local machines) may default to `bash`.
Replaces bash-specific shell command in one Makefile with a dash-compatible alternative, and re-enables the affected Makefile test.
Removes apparently redundant definition of `UNAME`.
Also see: [zulip discussion thread](https://rust-lang.zulipchat.com/#narrow/stream/131828-t-compiler/topic/how.20to.20run.2Fbless.20src.2Ftest.2Frun-make-fulldeps.2Fcoverage.20.3F)
r? `@pnkfelix`
FYI: `@wesleywiser` `@tmandry`
Along the way, we also implement a handful of diagnostics improvements
and fixes, particularly with respect to the special handling of `||` in
place of `|` and when there are leading verts in function params, which
don't allow top-level or-patterns anyway.
32-bit ARM: Emit `lr` instead of `r14` when specified as an `asm!` output register.
On 32-bit ARM platforms, the register `r14` has the alias `lr`. When used as an output register in `asm!`, rustc canonicalizes the name to `r14`. LLVM only knows the register by the name `lr`, and rejects it. This changes rustc's LLVM code generation to output `lr` instead.
closes#82052
r? ``@nagisa``
Remove unnecessary `Option` in `default_doc`
Previously, there were two different ways to encode the same info: `None` or
`Some(&[])`. Now there is only one way, `&[]`.
const_generics: Fix incorrect ty::ParamEnv::empty() usage
Fixes#80561
Not sure if I should keep the `debug!(..)`s or not but its the second time I've needed them so they sure seem useful lol
cc ``@lcnr``
r? ``@oli-obk``
const_generics: Dont evaluate array length const when handling errors
Fixes#79518Fixes#78246
cc ````@lcnr````
This was ICE'ing because we dont pass in the correct ``ParamEnv`` which meant that there was no ``Self: Foo`` predicate to make ``Self::Assoc`` well formed which caused an ICE when trying to normalize ``Self::Assoc`` in the mir interpreter
r? ````@varkor````
Add match pattern diagnostics regression test
Closes#72377 by adding a regression test.
This test case fails on stable but now works on beta and nightly. It *should* have worked already for years, the crucial point whether it is mentioned that some uncovered patterns are not explicitly mentioned.
Suggest to create a new `const` item if the `fn` in the array is a `const fn`
Fixes#73734. If the `fn` in the array repeat expression is a `const fn`, suggest creating a new `const` item. On nightly, suggest creating an inline `const` block. This PR also removes the `suggest_const_in_array_repeat_expressions` as it is no longer necessary.
Example:
```rust
fn main() {
// Should not compile but hint to create a new const item (stable) or an inline const block (nightly)
let strings: [String; 5] = [String::new(); 5];
println!("{:?}", strings);
}
```
Gives this error:
```
error[E0277]: the trait bound `std::string::String: std::marker::Copy` is not satisfied
--> $DIR/const-fn-in-vec.rs:3:32
|
2 | let strings: [String; 5] = [String::new(); 5];
| ^^^^^^^^^^^^^^^^^^ the trait `std::marker::Copy` is not implemented for `String`
|
= note: the `Copy` trait is required because the repeated element will be copied
```
With this change, this is the error message:
```
error[E0277]: the trait bound `String: Copy` is not satisfied
--> $DIR/const-fn-in-vec.rs:3:32
|
LL | let strings: [String; 5] = [String::new(); 5];
| ^^^^^^^^^^^^^^^^^^ the trait `Copy` is not implemented for `String`
|
= help: moving the function call to a new `const` item will resolve the error
```
