set `has_unconstrained_ty_var` when generalizing aliases in bivariant contexts
this previously prevented the `regression-31157` benchmark from building
r? `@compiler-errors`
coverage: Carve out hole spans in a separate early pass
When extracting spans from MIR for use in coverage instrumentation, we sometimes need to identify *hole spans* (currently just closures), and carve up the other spans so that they don't overlap with holes.
This PR simplifies the main coverage-span-refiner by extracting the hole-carving process into a separate early pass. That pass produces a series of independent buckets, and we run the span-refiner on each bucket separately.
There is almost no difference in the resulting mappings, other than in some edge cases involving macros.
rustc_codegen_ssa: fix `get_rpath_relative_to_output` panic when lib only contains file name
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When compiles program with `-C rpath=yes` but with no output filename specified, or with filename ONLY, we will get an ICE for now. Fix it by treat empty `output` path in `get_rpath_relative_to_output` as current dir.
Before this patch:
```bash
rustc -C prefer_dynamic=yes -C rpath=yes -O h.rs # ICE, no output filename specified
rustc -o hello -C prefer_dynamic=yes -C rpath=yes -O h.rs # ICE, output filename has no path
rustc -o ./hello -C prefer_dynamic=yes -C rpath=yes -O h.rs # Works
```
All those examples work after the patch.
Close#119571.
Close#125785.
Various `HirTyLowerer` cleanups
Previously there was some ad-hoc specialization going on, because you could call `allows_infer`, which basically was deciding between whether the trait object was backed by `FnCtxt` or by `ItemCtxt`. I moved all the different logic into dedicated methods on `HirTyLowerer` and removed `allows_infer`
best reviewed commit-by-commit
Add intra-doc-links to rustc_middle crate-level docs.
Makes it slightly faster to find these modules, as you don't need to hunt for them in the big list.
Detect when user is trying to create a lending `Iterator` and give a custom explanation
The scope for this diagnostic is to detect lending iterators specifically and it's main goal is to help beginners to understand that what they are trying to implement might not be possible for `Iterator` trait specifically.
I ended up to changing the wording from originally proposed in the ticket because it might be misleading otherwise: `Data` might have a lifetime parameter but it can be unrelated to items user is planning to return.
Fixes https://github.com/rust-lang/rust/issues/125337
`rustc --explain E0582` additional example
## Context
*From #124744*
Expands the example for E0582, an error ensuring that lifetime in a function's return type is sufficiently constrained (e.g. actually tied to some input type), to show an additional example where one sees the lifetime occurring syntactically among the relevant function input types, but is nonetheless rejected by rustc because a syntactic occurrence is not always sufficient.
`ct_infer` and `lower_ty` will correctly result in an error constant or type respectively, as they go through a `HirTyLowerer` method (just like `HirTyLowerer::allow_infer` is a method implemented by both implementors
`rustc_parse` top-level cleanups
A bunch of improvements in and around `compiler/rustc_parse/src/lib.rs`. Many of the changes streamline the API in that file from this (12 functions and one macro):
```
name args return type
---- ---- -----------
panictry_buffer! Result<T, Vec<Diag>> T
pub parse_crate_from_file path PResult<Crate>
pub parse_crate_attrs_from_file path PResult<AttrVec>
pub parse_crate_from_source_str name,src PResult<Crate>
pub parse_crate_attrs_from_source_str name,src PResult<AttrVec>
pub new_parser_from_source_str name,src Parser
pub maybe_new_parser_from_source_str name,src Result<Parser, Vec<Diag>>
pub new_parser_from_file path,error_sp Parser
maybe_source_file_to_parser srcfile Result<Parser, Vec<Diag>>
pub parse_stream_from_source_str name,src,override_sp TokenStream
pub source_file_to_stream srcfile,override_sp TokenStream
maybe_file_to_stream srcfile,override_sp Result<TokenStream, Vec<Diag>>
pub stream_to_parser stream,subparser_name Parser
```
to this:
```
name args return type
---- ---- -----------
unwrap_or_emit_fatal Result<T, Vec<Diag>> T
pub new_parser_from_source_str name,src Result<Parser, Vec<Diag>>
pub new_parser_from_file path,error_sp Result<Parser, Vec<Diag>>
new_parser_from_source_file srcfile Result<Parser, Vec<Diag>>
pub source_str_to_stream name,src,override_sp Result<TokenStream, Vec<Diag>>
source_file_to_stream srcfile,override_sp Result<TokenStream, Vec<Diag>>
```
I found the old API quite confusing, with lots of similar-sounding function names and no clear structure. I think the new API is much better.
r? `@spastorino`
Add `size_of` and `size_of_val` and `align_of` and `align_of_val` to the prelude
(Note: need to update the PR to add `align_of` and `align_of_val`, and remove the second commit with the myriad changes to appease the lint.)
Many, many projects use `size_of` to get the size of a type. However,
it's also often equally easy to hardcode a size (e.g. `8` instead of
`size_of::<u64>()`). Minimizing friction in the use of `size_of` helps
ensure that people use it and make code more self-documenting.
The name `size_of` is unambiguous: the name alone, without any prefix or
path, is self-explanatory and unmistakeable for any other functionality.
Adding it to the prelude cannot produce any name conflicts, as any local
definition will silently shadow the one from the prelude. Thus, we don't
need to wait for a new edition prelude to add it.
Currently we have an awkward mix of fallible and infallible functions:
```
new_parser_from_source_str
maybe_new_parser_from_source_str
new_parser_from_file
(maybe_new_parser_from_file) // missing
(new_parser_from_source_file) // missing
maybe_new_parser_from_source_file
source_str_to_stream
maybe_source_file_to_stream
```
We could add the two missing functions, but instead this commit removes
of all the infallible ones and renames the fallible ones leaving us with
these which are all fallible:
```
new_parser_from_source_str
new_parser_from_file
new_parser_from_source_file
source_str_to_stream
source_file_to_stream
```
This requires making `unwrap_or_emit_fatal` public so callers of
formerly infallible functions can still work.
This does make some of the call sites slightly more verbose, but I think
it's worth it for the simpler API. Also, there are two `catch_unwind`
calls and one `catch_fatal_errors` call in this diff that become
removable thanks this change. (I will do that in a follow-up PR.)
The first one is out-of-date -- there are no longer functions expr,
item, stmt. And I don't know what a "HOF" is.
The second one doesn't really tell you anything.
- Convert it from a macro to a function, which is nicer.
- Rename it as `unwrap_or_emit_fatal`, which is clearer.
- Fix the comment. In particular, `panictry!` no longer exists.
- Remove the unnecessary `use` declaration.
It has a single call site.
This also means `CFG_ATTR_{GRAMMAR_HELP,NOTE_REF}` can be moved into
`parse_cfg_attr`, now that it's the only function that uses them.
And the commit removes the line break in the URL.
Lexing converts source text into a token stream. Parsing converts a
token stream into AST fragments. This commit renames several lexing
operations that have "parse" in the name. I think these names have been
subtly confusing me for years.
This is just a `s/parse/lex/` on function names, with one exception:
`parse_stream_from_source_str` becomes `source_str_to_stream`, to make
it consistent with the existing `source_file_to_stream`. The commit also
moves that function's location in the file to be just above
`source_file_to_stream`.
The commit also cleans up a few comments along the way.
Convert `proc_macro_back_compat` lint to an unconditional error.
We still check for the `rental`/`allsorts-rental` crates. But now if they are detected we just emit a fatal error, instead of emitting a warning and providing alternative behaviour.
The original "hack" implementing alternative behaviour was added in #73345.
The lint was added in #83127.
The tracking issue is #83125.
The direct motivation for the change is that providing the alternative behaviour is interfering with #125174 and follow-on work.
r? ``@estebank``
Store the types of `ty::Expr` arguments in the `ty::Expr`
Part of #125958
In attempting to remove the `ty` field on `Const` it will become necessary to store the `Ty<'tcx>` inside of `Expr<'tcx>`. In order to do this without blowing up the size of `ConstKind`, we start storing the type/const args as `GenericArgs`
r? `@oli-obk`
Split smir `Const` into `TyConst` and `MirConst`
Part of #125958
Building a `smir::Const` currently requires accessing the `Ty<'tcx>` of a `ty::Const`. This will stop being possible in the future. Replicate the split in rustc of having a representation of type level constants and mir constants with the latter being able to store the former. Ideally we wouldnt have `MirConst::Ty` but 🤷♀️
r? `@oli-obk`
Streamline `nested` calls.
`TyCtxt` impls `PpAnn` in `compiler/rustc_middle/src/hir/map/mod.rs`. We can call that impl, which then calls the one on `intravisit::Map`, instead of calling the one on `intravisit::Map` directly, avoiding a cast and extra references.
r? `@lqd`
Improve renaming suggestion for names with leading underscores
Fixes#125650
Before:
```
error[E0425]: cannot find value `p` in this scope
--> test.rs:2:13
|
2 | let _ = p;
| ^
|
help: a local variable with a similar name exists, consider renaming `_p` into `p`
|
1 | fn a(p: i32) {
| ~
```
After:
```
error[E0425]: cannot find value `p` in this scope
--> test.rs:2:13
|
1 | fn a(_p: i32) {
| -- `_p` defined here
2 | let _ = p;
| ^
|
help: the leading underscore in `_p` marks it as unused, consider renaming it to `p`
|
1 | fn a(p: i32) {
| ~
```
This change doesn't exactly conform to what was proposed in the issue:
1. I've kept the suggested code instead of solely replacing it with the label
2. I've removed the "...similar name exists..." message instead of relocating to the usage span
3. You could argue that it still isn't completely clear that the change is referring to the definition (not the usage), but I'm not sure how to do this without playing down the fact that the error was caused by the usage of an undefined name.
Refactor `#[diagnostic::do_not_recommend]` support
This commit refactors the `#[do_not_recommend]` support in the old parser to also apply to projection errors and not only to selection errors. This allows the attribute to be used more widely.
Part of #51992
r? `@compiler-errors`
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