Currently, `Symbol::Debug` and `Symbol::Display` produce the same
output; neither wraps the symbol in double quotes.
This commit changes `Symbol::Debug` so it wraps the symbol in quotes.
This change brings `Symbol`'s behaviour in line with `String` and
`InternedString`. The change requires a couple of trivial test output
adjustments.
Likewise for `NestedMetaItem::tokens()`. Also, add
`MetaItemKind::token_trees_and_joints()`, which `MetaItemKind::tokens()`
now calls.
This avoids some unnecessary `TokenTree` to `TokenStream` conversions,
and removes the need for the clumsy
`TokenStream::append_to_tree_and_joint_vec()`.
The current code has this impl:
```
impl<T: Into<TokenStream>> iter::FromIterator<T> for TokenStream
```
If given an `IntoIterator<Item = TokenTree>`, it will convert each individual
`TokenTree` to a `TokenStream` (at the cost of two allocations: a `Vec`
and an `Lrc`). It will then merge those `TokenStream`s into a single
`TokenStream`. This is inefficient.
This commit changes the impl to this less general one:
```
impl iter::FromIterator<TokenTree> for TokenStream
```
It collects the `TokenTree`s into a single `Vec` first and then converts that
to a `TokenStream` by wrapping it in a single `Lrc`. The previous generality
was unnecessary; no other code needs changing.
This change speeds up several benchmarks by up to 4%.
Add a target setting to allow targets to specify whether the generated
`main` function should be passed `argc` and `argv` arguments. Set it
to false on wasm32-wasi, since WASI's `args::args()` calls into the
WASI APIs itself. This will allow the WASI toolchain to avoid linking
and running command-line argument initialization code when the arguments
aren't actually needed.
Rollup of 8 pull requests
Successful merges:
- #65237 (Move debug_map assertions after check for err)
- #65316 (make File::try_clone produce non-inheritable handles on Windows)
- #65319 (InterpCx: make memory field public)
- #65461 (Don't recommend ONCE_INIT in std::sync::Once)
- #65465 (Move syntax::ext to a syntax_expand and refactor some attribute logic)
- #65475 (add example for type_name)
- #65478 (fmt::Write is about string slices, not byte slices)
- #65486 (doc: fix typo in OsStrExt and OsStringExt)
Failed merges:
r? @ghost
Optimize dropck
This does two things: caches the `trivial_dropck` check by making it a query, and shifts around the implementation of the primary dropck itself to avoid allocating many small vectors.
