Optimize parse_cfgspecs.

In `parse_cfg`, we now construct a `FxHashSet<String>` directly instead of
constructing a `FxHashSet<Symbol>` and then immediately converting it to a
`FxHashSet<String>`(!)

(The type names made this behaviour non-obvious. The next commit will
make the type names clearer.)
This commit is contained in:
Nicholas Nethercote 2023-10-27 15:54:14 +11:00
parent 32986d895f
commit 75e415ba86

View File

@ -16,7 +16,7 @@ use rustc_parse::maybe_new_parser_from_source_str;
use rustc_query_impl::QueryCtxt;
use rustc_query_system::query::print_query_stack;
use rustc_session::config::{self, CheckCfg, ExpectedValues, Input, OutFileName, OutputFilenames};
use rustc_session::parse::{CrateConfig, ParseSess};
use rustc_session::parse::ParseSess;
use rustc_session::CompilerIO;
use rustc_session::Session;
use rustc_session::{lint, EarlyErrorHandler};
@ -67,7 +67,7 @@ pub fn parse_cfgspecs(
cfgspecs: Vec<String>,
) -> FxHashSet<(String, Option<String>)> {
rustc_span::create_default_session_if_not_set_then(move |_| {
let cfg = cfgspecs
cfgspecs
.into_iter()
.map(|s| {
let sess = ParseSess::with_silent_emitter(Some(format!(
@ -97,7 +97,10 @@ pub fn parse_cfgspecs(
}
MetaItemKind::NameValue(..) | MetaItemKind::Word => {
let ident = meta_item.ident().expect("multi-segment cfg key");
return (ident.name, meta_item.value_str());
return (
ident.name.to_string(),
meta_item.value_str().map(|sym| sym.to_string()),
);
}
}
}
@ -118,8 +121,7 @@ pub fn parse_cfgspecs(
error!(r#"expected `key` or `key="value"`"#);
}
})
.collect::<CrateConfig>();
cfg.into_iter().map(|(a, b)| (a.to_string(), b.map(|b| b.to_string()))).collect()
.collect::<FxHashSet<_>>()
})
}