Tweak `-Zmacro-stats` measurement.
It currently reports net size, i.e. size(output) - size(input). After some use I think this is sub-optimal, and it's better to just report size(output). Because for derive macros the input size is always 1, and for attribute macros it's almost always 1.
r? ```@petrochenkov```
Don't include current rustc version string in feature removed help
The version string is difficult to properly normalize out, and removing it isn't a huge deal (the user can query version info easily through `rustc --version` or `cargo --version`).
The normalization options were all non-ideal (see https://github.com/rust-lang/rust/pull/142940#issuecomment-2998518450):
- Per-test version string normalization is nasty to maintain, and we need to maintain `n` copies of it. See rust-lang/rust#142930 where the regex wasn't robust against different release channels.
- Centralized compiletest normalization (with a directive opt-out) is also not ideal, because `cfg(version(..))` tests can't have those accidentally normalized out (and you'd have to remember to opt-out).
r? `@workingjubilee` (discussed in rust-lang/rust#142940)
mbe: Clean up code with non-optional `NonterminalKind`
Since [rust-lang/rust#128425], the fragment specifier is unconditionally required in all
editions. This means `NonTerminalKind` no longer needs to be optional,
as we can reject this code during the expansion of `macro_rules!` rather
than handling it throughout the code. Do this cleanup here.
[rust-lang/rust#128425]: https://github.com/rust-lang/rust/pull/128425
The version string is difficult to properly normalize out, and removing
it isn't a huge deal (the user can query version info easily through
`rustc --version` or `cargo --version`).
The normalization options were all non-ideal:
- Per-test version string normalization is nasty to maintain, and we
need to maintain `n` copies of it.
- Centralized compiletest normalization (with a directive opt-out) is
also not ideal, because `cfg(version(..))` tests can't have those
accidentally normalized out (and you'd have to remember to opt-out).
Since [1], the fragment specifier is unconditionally required in all
editions. This means `NonTerminalKind` no longer needs to be optional,
as we can reject this code during the expansion of `macro_rules!` rather
than handling it throughout the code. Do this cleanup here.
[1]: https://github.com/rust-lang/rust/pull/128425
It currently reports net size, i.e. size(output) - size(input). After
some use I think this is sub-optimal, and it's better to just report
size(output). Because for derive macros the input size is always 1, and
for attribute macros it's almost always 1.
completely deduplicate `Visitor` and `MutVisitor`
r? oli-obk
This closesrust-lang/rust#127615.
### Discussion
> * Give every `MutVisitor::visit_*` method a corresponding `flat_map_*` method.
Not every AST node exists in a location where they can be mapped to multiple instances of themselves. Not every AST node exists in a location where they can be removed from existence (e.g. `filter_map_expr`). I don't think this is doable.
> * Give every `MutVisitor::visit_*` method a corresponding `Visitor` method and vice versa
The only three remaining method-level asymmetries after this PR are `visit_stmt` and `visit_nested_use_tree` (only on `Visitor`) and `visit_span` (only on `MutVisitor`).
`visit_stmt` doesn't seem applicable to `MutVisitor` because `walk_flat_map_stmt_kind` will ask `flat_map_item` / `filter_map_expr` to potentially turn a single `Stmt` to multiple based on what a visitor wants. So only using `flat_map_stmt` seems appropriate.
`visit_nested_use_tree` is used for `rustc_resolve` to track stuff. Not useful for `MutVisitor` for now.
`visit_span` is currently not used for `MutVisitor` already, it was just kept in case we want to revive rust-lang/rust#127241. cc `@cjgillot` maybe we could remove for now and re-insert later if we find a use-case? It does involve some extra effort to maintain.
* Remaining FIXMEs
`visit_lifetime` has an extra param for `Visitor` that's not in `MutVisitor`. This is again something only used by `rustc_resolve`. I think we can keep that symmetry for now.
Introduce `MacroTcbCtx` that holds everything relevant to transcription.
This allows for the following changes:
* Split `transcribe_sequence` and `transcribe_metavar` out of the
heavily nested `transcribe`
* Split `metavar_expr_concat` out of `transcribe_metavar_expr`
This is a nonfunctional change.
It collects data about macro expansions and prints them in a table after
expansion finishes. It's very useful for detecting macro bloat,
especially for proc macros.
Details:
- It measures code snippets by pretty-printing them and then measuring
lines and bytes. This required a bunch of additional pretty-printing
plumbing, in `rustc_ast_pretty` and `rustc_expand`.
- The measurement is done in `MacroExpander::expand_invoc`.
- The measurements are stored in `ExtCtxt::macro_stats`.
remove `visit_clobber` and move `DummyAstNode` to `rustc_expand`
`visit_clobber` is not really useful except for one niche purpose
involving generic code. We should just use the replace logic where we
can.
Do not get proc_macro from the sysroot in rustc
With the stage0 refactor the proc_macro version found in the sysroot will no longer always match the proc_macro version that proc-macros get compiled with by the rustc executable that uses this proc_macro. This will cause problems as soon as the ABI of the bridge gets changed to implement new features or change the way existing features work.
To fix this, this commit changes rustc crates to depend directly on the local version of proc_macro which will also be used in the sysroot that rustc will build.
Reorder `ast::ItemKind::{Struct,Enum,Union}` fields.
So they match the order of the parts in the source code, e.g.:
```
struct Foo<T, U> { t: T, u: U }
<-><----> <------------>
/ | \
ident generics variant_data
```
r? `@fee1-dead`
So they match the order of the parts in the source code, e.g.:
```
struct Foo<T, U> { t: T, u: U }
<-><----> <------------>
/ | \
ident generics variant_data
```
With the stage0 refactor the proc_macro version found in the sysroot
will no longer always match the proc_macro version that proc-macros get
compiled with by the rustc executable that uses this proc_macro. This
will cause problems as soon as the ABI of the bridge gets changed to
implement new features or change the way existing features work.
To fix this, this commit changes rustc crates to depend directly on the
local version of proc_macro which will also be used in the sysroot that
rustc will build.
`mut_visit.rs` has a single function with a `noop_` prefix:
`noop_filter_map_expr`. This commit renames as `walk_filter_map_expr`
which is consistent with other functions in this file.
The commit also removes out-of-date comments that refer to `noop_*`
methods.
make `rustc_attr_parsing` less dominant in the rustc crate graph
It has/had a glob re-export of `rustc_attr_data_structures`, which is a crate much lower in the graph, and a lot of crates were using it *just* (or *mostly*) for that re-export, while they can rely on `rustc_attr_data_structures` directly.
Previous graph:

Graph with this PR:

The first commit keeps the re-export, and just changes the dependency if possible. The second commit is the "breaking change" which removes the re-export, and "explicitly" adds the `rustc_attr_data_structures` dependency where needed. It also switches over some src/tools/*.
The second commit is actually a lot more involved than I expected. Please let me know if it's a better idea to back it out and just keep the first commit.
This commit does the following.
- Changes it from `Lrc<Box<dyn ToAttrTokenStream>>` to
`Lrc<LazyAttrTokenStreamInner>`.
- Reworks `LazyAttrTokenStreamImpl` as `LazyAttrTokenStreamInner`, which
is a two-variant enum.
- Removes the `ToAttrTokenStream` trait and the two impls of it.
The recursion limit must be increased in some crates otherwise rustdoc
aborts.
Most notably, the `FIXME` for suboptimal printing of `use` groups in
`tests/ui/macros/stringify.rs` is fixed. And all other test output
changes result in pretty printed output being closer to the original
formatting in the source code.