Overhaul filename handling for cross-compiler consistency
This PR overhauls the way we handle filenames in the compiler and `rmeta` in order to achieve achieve cross-compiler consistency (ie. having the same path no matter if the filename was created in the current compiler session or is coming from `rmeta`).
This is required as some parts of the compiler rely on consistent paths for the soundness of generated code (see rust-lang/rust#148328).
In order to achieved consistency multiple steps are being taken by this PR:
- by making `RealFileName` immutable
- by only having `SourceMap::to_real_filename` create `RealFileName`
- currently `RealFileName` can be created from any `Path` and are remapped afterwards, which creates consistency issue
- by also making `RealFileName` holds it's working directory, embeddable name and the remapped scopes
- this removes the need for a `Session`, to know the current(!) scopes and cwd, which is invalid as they may not be equal to the scopes used when creating the filename
In order for `SourceMap::to_real_filename` to know which scopes to apply `FilePathMapping` now takes the current remapping scopes to apply, which makes `FileNameDisplayPreference` and company useless and are removed.
This PR is split-up in multiple commits (unfortunately not atomic), but should help review the changes.
Unblocks https://github.com/rust-lang/rust/pull/147611
Fixes https://github.com/rust-lang/rust/issues/148328
This commit refactors `SourceMap` and most importantly `RealFileName` to
make it self-contained in order to achieve cross-compiler consistency.
This is achieved:
- by making `RealFileName` immutable
- by only having `SourceMap::to_real_filename` create `RealFileName`
- by also making `RealFileName` holds it's working directory,
it's embeddable name and the remapped scopes
- by making most `FileName` and `RealFileName` methods take a scope as
an argument
In order for `SourceMap::to_real_filename` to know which scopes to apply
`FilePathMapping` now takes the current remapping scopes to apply, which
makes `FileNameDisplayPreference` and company useless and are removed.
The scopes type `RemapPathScopeComponents` was moved from
`rustc_session::config` to `rustc_span`.
The previous system for scoping the local/remapped filenames
`RemapFileNameExt::for_scope` is no longer useful as it's replaced by
methods on `FileName` and `RealFileName`.
Point at span within local macros even when error happens in nested external macro
Address issue noticed at https://users.rust-lang.org/t/error-message-does-not-specify-where-in-macro/135157/1. On errors occurring within a macro expansion, point at the innermost local macro expansion point.
```
error[E0308]: mismatched types
--> $DIR/macro-span-caller-replacement.rs:5:17
|
LL | s = format!("{arg}");
| ^^^^^^^^^^^^^^^^ expected `&str`, found `String`
...
LL | macro_with_format!();
| -------------------- in this macro invocation
|
= note: this error originates in the macro `format` which comes from the expansion of the macro `macro_with_format` (in Nightly builds, run with -Z macro-backtrace for more info)
```
remove duplicated columns from `rustc_error_code::error_codes!`
Possible because of rust-lang/rust#146308 ~~, but currently still blocked on the next stage0 bump~~.
```
error[E0308]: mismatched types
--> $DIR/macro-span-caller-replacement.rs:5:17
|
LL | s = format!("{arg}");
| ^^^^^^^^^^^^^^^^ expected `&str`, found `String`
...
LL | macro_with_format!();
| -------------------- in this macro invocation
|
= note: this error originates in the macro `format` which comes from the expansion of the macro `macro_with_format` (in Nightly builds, run with -Z macro-backtrace for more info)
```
chore: Update annotate-snippets to 0.12.10
This PR updates `annotate-snippets` to `0.12.10`, which [includes a fix](756366223c/CHANGELOG.md (fixed)) that modifies some test output.
feat: Enable annotate-snippets' simd feature
`annotate-snippets` `simd` feature enables the use of `memchr` when searching for `char`/`str`. This should hopefully improve performance when [`annotate-snippets` is passed large `source`](https://github.com/rust-lang/rust/pull/148188#issuecomment-3550280300).
Address annotate-snippets test differences
When `annotate-snippets` became the default renderer on `nightly`, it came with a few rendering differences. I was not entirely happy with a few of the differences, and after talking with ``@davidtwco`` about them, I decided to address those that seemed like regressions.
r? ``@davidtwco``
Fix ICE caused by invalid spans for shrink_file
Fixesrust-lang/rust#148732
There are two issues in this function:
1. the original issue is caused by a typo error, which is fixed in the first commit
2. another different ice(Patch span `7..7` is beyond the end of buffer `0`) will be reported after fixing the first one, is caused by spans cross file boundaries due to macro expansion. It is fixed in the second commit.
r? `@nnethercote`
edited: also fixesrust-lang/rust#148684, added a new testcase for it in the last commit.
fix: Only special case single line item attribute suggestions
`rustc` currently special cases suggestions to add [`#[derive(_)]\n` and other attributes](dc1feabef2/compiler/rustc_errors/src/emitter.rs (L2288C36-L2288C72)), to add more context to the suggestions.
> // The suggestion adds an entire line of code, ending on a newline, so we'll also
> // print the *following* line, to provide context of what we're advising people to
> // do. Otherwise you would only see contextless code that can be confused for
> // already existing code, despite the colors and UI elements.
> // We special case `#[derive(_)]\n` and other attribute suggestions, because those
> // are the ones where context is most useful.
This special case is a bit broad at the moment and applies to suggestions just to add an attribute, as well as suggestions that contain an attribute and other code, i.e.
```rust
#[derive(Clone)]
```
and
```rust
#[cfg(not(test))]
impl Default for NewWithCfg {
fn default() -> Self {
Self::new()
}
}
```
In the latter case, adding a line for context after the suggestion doesn't provide much benefit. Example:

This PR makes it so that this special case only applies to suggestions that just add an attribute and nothing else. This will also make `rustc`'s output match `annotate-snippets`.
```
error[E0277]: the trait bound `u32: Trait` is not satisfied
--> $DIR/trait_objects_fail.rs:26:9
|
LL | foo(&10_u32);
| ^^^^^^^ the trait `Trait` is not implemented for `u32`
|
help: the trait `Trait<12>` is not implemented for `u32`
but trait `Trait<2>` is implemented for it
--> $DIR/trait_objects_fail.rs:7:1
|
LL | impl Trait<2> for u32 {}
| ^^^^^^^^^^^^^^^^^^^^^
= note: required for the cast from `&u32` to `&dyn Trait`
```
Pointing at the `impl` definition that *could* apply given a different self type is particularly useful when it has a blanket self type, as it might not be obvious and is not trivially greppable:
```
error[E0277]: the trait bound `RawImpl<_>: Raw<_>` is not satisfied
--> $DIR/issue-62742.rs:4:5
|
LL | WrongImpl::foo(0i32);
| ^^^^^^^^^ unsatisfied trait bound
|
help: the trait `Raw<_>` is not implemented for `RawImpl<_>`
but trait `Raw<[_]>` is implemented for it
--> $DIR/issue-62742.rs:29:1
|
LL | impl<T> Raw<[T]> for RawImpl<T> {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
note: required by a bound in `SafeImpl`
--> $DIR/issue-62742.rs:33:35
|
LL | pub struct SafeImpl<T: ?Sized, A: Raw<T>>(PhantomData<(A, T)>);
| ^^^^^^ required by this bound in `SafeImpl`
```