Improve CheckCfg internal representation

1 files changed, 16 insertions, 6 deletions

diff --git a/compiler/rustc_interface/src/interface.rs b/compiler/rustc_interface/src/interface.rs
index 609fc4b78c0..5e0d59bf1b1 100644
--- a/compiler/rustc_interface/src/interface.rs
+++ b/compiler/rustc_interface/src/interface.rs
@@ -169,11 +169,12 @@ pub fn parse_check_cfg(specs: Vec<String>) -> CheckCfg {
                     Ok(meta_item) if parser.token == token::Eof => {
                         if let Some(args) = meta_item.meta_item_list() {
                             if meta_item.has_name(sym::names) {
-                                cfg.names_checked = true;
+                                let names_valid =
+                                    cfg.names_valid.get_or_insert_with(|| FxHashSet::default());
                                 for arg in args {
                                     if arg.is_word() && arg.ident().is_some() {
                                         let ident = arg.ident().expect("multi-segment cfg key");
-                                        cfg.names_valid.insert(ident.name.to_string());
+                                        names_valid.insert(ident.name.to_string());
                                     } else {
                                         error!("`names()` arguments must be simple identifers");
                                     }
@@ -182,14 +183,19 @@ pub fn parse_check_cfg(specs: Vec<String>) -> CheckCfg {
                             } else if meta_item.has_name(sym::values) {
                                 if let Some((name, values)) = args.split_first() {
                                     if name.is_word() && name.ident().is_some() {
+                                        let values_valid = cfg
+                                            .values_valid
+                                            .get_or_insert_with(|| FxHashMap::default());
                                         let ident = name.ident().expect("multi-segment cfg key");
-                                        cfg.values_checked.insert(ident.to_string());
+                                        let ident_values = values_valid
+                                            .entry(ident.to_string())
+                                            .or_insert_with(|| FxHashSet::default());
+
                                         for val in values {
                                             if let Some(LitKind::Str(s, _)) =
                                                 val.literal().map(|lit| &lit.kind)
                                             {
-                                                cfg.values_valid
-                                                    .insert((ident.to_string(), s.to_string()));
+                                                ident_values.insert(s.to_string());
                                             } else {
                                                 error!(
                                                     "`values()` arguments must be string literals"
@@ -219,7 +225,11 @@ pub fn parse_check_cfg(specs: Vec<String>) -> CheckCfg {
             );
         }
 
-        cfg.names_valid.extend(cfg.values_checked.iter().cloned());
+        if let Some(values_valid) = &cfg.values_valid {
+            if let Some(names_valid) = &mut cfg.names_valid {
+                names_valid.extend(values_valid.keys().cloned());
+            }
+        }
         cfg
     })
 }