Rollup merge of #117376 - nnethercote:rustc_interface-more, r=oli-obk

More `rustc_interface` cleanups

In particular, following up #117268 with more improvement to `--cfg`/`--check-cfg` handling.

r? ``@oli-obk``

2 files changed, 12 insertions, 53 deletions

diff --git a/compiler/rustc_session/src/config.rs b/compiler/rustc_session/src/config.rs
index 854e2b77993..a8ebab4ae33 100644
--- a/compiler/rustc_session/src/config.rs
+++ b/compiler/rustc_session/src/config.rs
@@ -1247,8 +1247,8 @@ pub const fn default_lib_output() -> CrateType {
     CrateType::Rlib
 }
 
-fn default_configuration(sess: &Session) -> Cfg<Symbol> {
-    // NOTE: This should be kept in sync with `CheckCfg::<Symbol>::fill_well_known` below.
+fn default_configuration(sess: &Session) -> Cfg {
+    // NOTE: This should be kept in sync with `CheckCfg::fill_well_known` below.
     let end = &sess.target.endian;
     let arch = &sess.target.arch;
     let wordsz = sess.target.pointer_width.to_string();
@@ -1358,56 +1358,21 @@ fn default_configuration(sess: &Session) -> Cfg<Symbol> {
 }
 
 /// The parsed `--cfg` options that define the compilation environment of the
-/// crate, used to drive conditional compilation. `T` is always `String` or
-/// `Symbol`. Strings are used temporarily very early on. Once the the main
-/// symbol interner is running, they are converted to symbols.
+/// crate, used to drive conditional compilation.
 ///
 /// An `FxIndexSet` is used to ensure deterministic ordering of error messages
 /// relating to `--cfg`.
-pub type Cfg<T> = FxIndexSet<(T, Option<T>)>;
+pub type Cfg = FxIndexSet<(Symbol, Option<Symbol>)>;
 
-/// The parsed `--check-cfg` options. The `<T>` structure is similar to `Cfg`.
-pub struct CheckCfg<T> {
+/// The parsed `--check-cfg` options.
+#[derive(Default)]
+pub struct CheckCfg {
     /// Is well known names activated
     pub exhaustive_names: bool,
     /// Is well known values activated
     pub exhaustive_values: bool,
     /// All the expected values for a config name
-    pub expecteds: FxHashMap<T, ExpectedValues<T>>,
-}
-
-impl<T> Default for CheckCfg<T> {
-    fn default() -> Self {
-        CheckCfg {
-            exhaustive_names: false,
-            exhaustive_values: false,
-            expecteds: FxHashMap::default(),
-        }
-    }
-}
-
-impl CheckCfg<String> {
-    pub fn intern(self) -> CheckCfg<Symbol> {
-        CheckCfg {
-            exhaustive_names: self.exhaustive_names,
-            exhaustive_values: self.exhaustive_values,
-            expecteds: self
-                .expecteds
-                .into_iter()
-                .map(|(name, values)| {
-                    (
-                        Symbol::intern(&name),
-                        match values {
-                            ExpectedValues::Some(values) => ExpectedValues::Some(
-                                values.into_iter().map(|b| b.map(|b| Symbol::intern(&b))).collect(),
-                            ),
-                            ExpectedValues::Any => ExpectedValues::Any,
-                        },
-                    )
-                })
-                .collect(),
-        }
-    }
+    pub expecteds: FxHashMap<Symbol, ExpectedValues<Symbol>>,
 }
 
 pub enum ExpectedValues<T> {
@@ -1442,7 +1407,7 @@ impl<'a, T: Eq + Hash + Copy + 'a> Extend<&'a T> for ExpectedValues<T> {
     }
 }
 
-impl CheckCfg<Symbol> {
+impl CheckCfg {
     pub fn fill_well_known(&mut self, current_target: &Target) {
         if !self.exhaustive_values && !self.exhaustive_names {
             return;
@@ -1582,13 +1547,7 @@ impl CheckCfg<Symbol> {
     }
 }
 
-pub fn build_configuration(sess: &Session, user_cfg: Cfg<String>) -> Cfg<Symbol> {
-    // We can now intern these strings.
-    let mut user_cfg: Cfg<Symbol> = user_cfg
-        .into_iter()
-        .map(|(a, b)| (Symbol::intern(&a), b.map(|b| Symbol::intern(&b))))
-        .collect();
-
+pub fn build_configuration(sess: &Session, mut user_cfg: Cfg) -> Cfg {
     // Combine the configuration requested by the session (command line) with
     // some default and generated configuration items.
     let default_cfg = default_configuration(sess);
diff --git a/compiler/rustc_session/src/parse.rs b/compiler/rustc_session/src/parse.rs
index 5b98ee5d992..4d20d6d4187 100644
--- a/compiler/rustc_session/src/parse.rs
+++ b/compiler/rustc_session/src/parse.rs
@@ -188,8 +188,8 @@ pub fn add_feature_diagnostics_for_issue(
 pub struct ParseSess {
     pub span_diagnostic: Handler,
     pub unstable_features: UnstableFeatures,
-    pub config: Cfg<Symbol>,
-    pub check_config: CheckCfg<Symbol>,
+    pub config: Cfg,
+    pub check_config: CheckCfg,
     pub edition: Edition,
     /// Places where raw identifiers were used. This is used to avoid complaining about idents
     /// clashing with keywords in new editions.