Speed up `LexicalResolve::expansion()`
A couple of improvements that speed up `unicode_normalization` by about 4%. The first commit was enabled by the improvements to `BitSet` iteration in #65425.
r? @nikomatsakis
Avoid unnecessary `TokenTree` to `TokenStream` conversions
A `TokenStream` contains any number of `TokenTrees`. Therefore, a single `TokenTree` can be promoted to a `TokenStream`. But doing so costs two allocations: one for the single-element `Vec`, and one for the `Lrc`. (An `IsJoint` value also must be added; the default is `NonJoint`.)
The current code converts `TokenTree`s to `TokenStream`s unnecessarily in a few places. This PR removes some of these unnecessary conversions, both simplifying the code and speeding it up.
r? @petrochenkov
Disable Go and OCaml bindings when building LLVM
Instead of instaling OCaml bindings in a location where installation
will not fail, don't build them in the first place.
Prepare `MutVisitor`s to handle interned projections
The following are all the files where mir's `MutVisitor` is implemented. The `-` there stands for no changes, `visit_place` wasn't making any change on `Place`s. `x` stands for this file was changed to make `visit_place` do whatever it was doing with the base but avoid modifying the projection, instead just create a new one and assign to it.
```
[-] src/librustc_mir/transform/no_landing_pads.rs
[x] src/librustc_mir/transform/promote_consts.rs
[x] src/librustc_mir/transform/generator.rs
[x] src/librustc_mir/transform/erase_regions.rs
[-] src/librustc_mir/transform/instcombine.rs
[x] src/librustc_mir/transform/inline.rs
[x] src/librustc_mir/transform/simplify.rs
[x] src/librustc_mir/util/def_use.rs
[-] src/librustc_mir/transform/const_prop.rs
[-] src/librustc_mir/transform/cleanup_post_borrowck.rs
[x] src/librustc_mir/borrow_check/nll/renumber.rs
[-] src/librustc_mir/transform/copy_prop.rs
```
There is some code repetition, just created the PR so we can start discussing it.
/cc @oli-obk @nikomatsakis
Always inline `mem::{size_of,align_of}` in debug builds
Those two are const fn and do not have any arguments. Inlining
helps reducing generated code size in debug builds.
See also #64996.
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.
