rustc: Move features from Session to GlobalCtxt

Removes two pieces of mutable state.
Follow up to #114622.

compiler/rustc_builtin_macros/src/assert.rs

@@ -69,7 +69,7 @@ pub fn expand_assert<'cx>(
     // If `generic_assert` is enabled, generates rich captured outputs
     //
     // FIXME(c410-f3r) See https://github.com/rust-lang/rust/issues/96949
-    else if let Some(features) = cx.ecfg.features && features.generic_assert {
+    else if cx.ecfg.features.generic_assert {
         context::Context::new(cx, call_site_span).build(cond_expr, panic_path())
     }
     // If `generic_assert` is not enabled, only outputs a literal "assertion failed: ..."

compiler/rustc_builtin_macros/src/cfg.rs

@@ -24,7 +24,7 @@ pub fn expand_cfg(
                 &cfg,
                 &cx.sess.parse_sess,
                 cx.current_expansion.lint_node_id,
-                cx.ecfg.features,
+                Some(cx.ecfg.features),
             );
             MacEager::expr(cx.expr_bool(sp, matches_cfg))
         }

compiler/rustc_builtin_macros/src/cfg_eval.rs

@@ -31,10 +31,11 @@ pub(crate) fn expand(
 
 pub(crate) fn cfg_eval(
     sess: &Session,
-    features: Option<&Features>,
+    features: &Features,
     annotatable: Annotatable,
     lint_node_id: NodeId,
 ) -> Annotatable {
+    let features = Some(features);
     CfgEval { cfg: &mut StripUnconfigured { sess, features, config_tokens: true, lint_node_id } }
         .configure_annotatable(annotatable)
         // Since the item itself has already been configured by the `InvocationCollector`,

compiler/rustc_builtin_macros/src/proc_macro_harness.rs

@@ -5,6 +5,7 @@ use rustc_ast::{self as ast, attr, NodeId};
 use rustc_ast_pretty::pprust;
 use rustc_expand::base::{parse_macro_name_and_helper_attrs, ExtCtxt, ResolverExpand};
 use rustc_expand::expand::{AstFragment, ExpansionConfig};
+use rustc_feature::Features;
 use rustc_session::Session;
 use rustc_span::hygiene::AstPass;
 use rustc_span::source_map::SourceMap;
@@ -46,13 +47,14 @@ struct CollectProcMacros<'a> {
 pub fn inject(
     krate: &mut ast::Crate,
     sess: &Session,
+    features: &Features,
     resolver: &mut dyn ResolverExpand,
     is_proc_macro_crate: bool,
     has_proc_macro_decls: bool,
     is_test_crate: bool,
     handler: &rustc_errors::Handler,
 ) {
-    let ecfg = ExpansionConfig::default("proc_macro".to_string());
+    let ecfg = ExpansionConfig::default("proc_macro".to_string(), features);
     let mut cx = ExtCtxt::new(sess, ecfg, resolver, None);
 
     let mut collect = CollectProcMacros {

compiler/rustc_builtin_macros/src/standard_library_imports.rs

@@ -1,6 +1,7 @@
 use rustc_ast::{self as ast, attr};
 use rustc_expand::base::{ExtCtxt, ResolverExpand};
 use rustc_expand::expand::ExpansionConfig;
+use rustc_feature::Features;
 use rustc_session::Session;
 use rustc_span::edition::Edition::*;
 use rustc_span::hygiene::AstPass;
@@ -13,6 +14,7 @@ pub fn inject(
     pre_configured_attrs: &[ast::Attribute],
     resolver: &mut dyn ResolverExpand,
     sess: &Session,
+    features: &Features,
 ) -> usize {
     let orig_num_items = krate.items.len();
     let edition = sess.parse_sess.edition;
@@ -39,7 +41,7 @@ pub fn inject(
     let span = DUMMY_SP.with_def_site_ctxt(expn_id.to_expn_id());
     let call_site = DUMMY_SP.with_call_site_ctxt(expn_id.to_expn_id());
 
-    let ecfg = ExpansionConfig::default("std_lib_injection".to_string());
+    let ecfg = ExpansionConfig::default("std_lib_injection".to_string(), features);
     let cx = ExtCtxt::new(sess, ecfg, resolver, None);
 
     // .rev() to preserve ordering above in combination with insert(0, ...)

compiler/rustc_builtin_macros/src/test_harness.rs

@@ -41,7 +41,12 @@ struct TestCtxt<'a> {
 
 /// Traverse the crate, collecting all the test functions, eliding any
 /// existing main functions, and synthesizing a main test harness
-pub fn inject(krate: &mut ast::Crate, sess: &Session, resolver: &mut dyn ResolverExpand) {
+pub fn inject(
+    krate: &mut ast::Crate,
+    sess: &Session,
+    features: &Features,
+    resolver: &mut dyn ResolverExpand,
+) {
     let span_diagnostic = sess.diagnostic();
     let panic_strategy = sess.panic_strategy();
     let platform_panic_strategy = sess.target.panic_strategy;
@@ -76,7 +81,7 @@ pub fn inject(krate: &mut ast::Crate, sess: &Session, resolver: &mut dyn Resolve
             resolver,
             reexport_test_harness_main,
             krate,
-            &sess.features_untracked(),
+            features,
             panic_strategy,
             test_runner,
         )
@@ -243,9 +248,7 @@ fn generate_test_harness(
     panic_strategy: PanicStrategy,
     test_runner: Option<ast::Path>,
 ) {
-    let mut econfig = ExpansionConfig::default("test".to_string());
-    econfig.features = Some(features);
-
+    let econfig = ExpansionConfig::default("test".to_string(), features);
     let ext_cx = ExtCtxt::new(sess, econfig, resolver, None);
 
     let expn_id = ext_cx.resolver.expansion_for_ast_pass(