Use Symbol more
#60630
Use Symbol more
#60630
Conversation
rust-highfive
added
the
S-waiting-on-review
|
@bors try |
|
⌛ Trying commit b28d0aeaa86dd5079501c37d439b60771c34b2e8 with merge 1a89a3215ec97a7b0b2a010b773e7b8be90f6f4e... |
|
bors seems to have gotten stuck @bors try |
|
💥 Test timed out |
|
@oli-obk I think you have to use |
|
@bors retry |
|
⌛ Trying commit b28d0aeaa86dd5079501c37d439b60771c34b2e8 with merge ce805fd53ba59be4d9bd0f0987f1e5b764831307... |
|
☔ The latest upstream changes (presumably #60246) made this pull request unmergeable. Please resolve the merge conflicts. |
|
☀️ Try build successful - checks-travis |
|
@rust-timer build ce805fd53ba59be4d9bd0f0987f1e5b764831307 |
|
Success: Queued ce805fd53ba59be4d9bd0f0987f1e5b764831307 with parent b92d360, comparison URL. |
|
Finished benchmarking try commit ce805fd53ba59be4d9bd0f0987f1e5b764831307 |
|
I think github is being bugged by time travellers today |
|
One 1.4% perf improvement, many small ones (<1%) |
|
(I haven't done a full review but this does sound like something I've been wanting for a long time) |
|
The |
nnethercote
force-pushed
the
use-Symbol-more
branch
from
b28d0ae
to
6df17b0
Compare
src/libsyntax_pos/symbol.rs
Outdated
| } | ||
|
|
||
| // Non-identifer symbols that can be referred to with syntax_pos::nisymbols::*. | ||
| NISymbols { |
There was a problem hiding this comment.
"Non-identness" doesnt' really matter, entries in the Symbols { ... } block should probably just allow an optional : "non-ident" literal (with everything generated in one mod symbols).
There was a problem hiding this comment.
Ah, I didn't realize that was possible. Good suggestion, I will implement it.
There was a problem hiding this comment.
I'd like us to have 2 namespaces here, so if you use symbols::a you know you're getting a and not some other identifier. It also ensure there won't be any name conflicts if you add a: "b" and you want to add a later.
We could probably rename symbols to idents in that case.
|
So, my primary concern is that we are front-loading interning of about 500 strings and do it in every compilation session even if most of them won't be actually used. Could you measure how much time the UI test suite (a lot of little programs) takes with and without these changes? |
petrochenkov
removed
the
S-waiting-on-review
Use `Symbol` more A `Symbol` can be equated with a string (e.g. `&str`). This involves a TLS lookup to get the chars (and a Mutex lock in a parallel compiler) and then a char-by-char comparison. This functionality is convenient but avoids one of the main benefits of `Symbol`s, which is fast equality comparisons. This PR removes the `Symbol`/string equality operations, forcing a lot of existing string occurrences to become `Symbol`s. Fortunately, these are almost all static strings (many are attribute names) and we can add static `Symbol`s as necessary, and very little extra interning occurs. The benefits are (a) a slight speedup (possibly greater in a parallel compiler), and (b) the code is a lot more principled about `Symbol` use. The main downside is verbosity, particularly with more `use syntax::symbol::symbols` items. r? @Zoxc
|
☀️ Test successful - checks-travis, status-appveyor |
Simplify use of keyword symbols They mirror non-keyword symbols now (see #60630). `keywords::MyKeyword.name()` -> `kw::MyKeyword` `keywords::MyKeyword.ident()` -> `Ident::with_empty_ctxt(kw::MyKeyword)` (not common) `keywords::Invalid.ident()` -> `Ident::invalid()` (more common) Keywords are simply `Symbol` constants now, the `Keyword` struct is eliminated. This means `kw::MyKeyword` can now be used in `match` in particular.
`Symbol` received the same treatment in rust-lang#60630. Also, we can derive `PartialEq` for `InternedString`.
… r=<try> Remove impls for `InternedString`/string equality. `Symbol` received the same treatment in #60630. Also, we can derive `PartialEq` for `InternedString`. r? @petrochenkov
…alEq-impls, r=petrochenkov Remove impls for `InternedString`/string equality. `Symbol` received the same treatment in rust-lang#60630. Also, we can derive `PartialEq` for `InternedString`. r? @petrochenkov
…alEq-impls, r=petrochenkov Remove impls for `InternedString`/string equality. `Symbol` received the same treatment in rust-lang#60630. Also, we can derive `PartialEq` for `InternedString`. r? @petrochenkov
Simplify use of keyword symbols They mirror non-keyword symbols now (see #60630). `keywords::MyKeyword.name()` -> `kw::MyKeyword` `keywords::MyKeyword.ident()` -> `Ident::with_empty_ctxt(kw::MyKeyword)` (not common) `keywords::Invalid.ident()` -> `Ident::invalid()` (more common) Keywords are simply `Symbol` constants now, the `Keyword` struct is eliminated. This means `kw::MyKeyword` can now be used in `match` in particular.
A
Symbolcan be equated with a string (e.g.&str). This involves aTLS lookup to get the chars (and a Mutex lock in a parallel compiler)
and then a char-by-char comparison. This functionality is convenient but
avoids one of the main benefits of
Symbols, which is fast equalitycomparisons.
This PR removes the
Symbol/string equality operations, forcing a lotof existing string occurrences to become
Symbols. Fortunately, theseare almost all static strings (many are attribute names) and we can add
static
Symbols as necessary, and very little extra interning occurs.The benefits are (a) a slight speedup (possibly greater in a parallel
compiler), and (b) the code is a lot more principled about
Symboluse.The main downside is verbosity, particularly with more
use syntax::symbol::symbolsitems.r? @Zoxc