fix pre-expansion linting infra

src/libpanic_unwind/emcc.rs

@@ -6,8 +6,6 @@
 //! Emscripten's runtime always implements those APIs and does not
 //! implement libunwind.
 
-#![allow(private_no_mangle_fns)]
-
 use alloc::boxed::Box;
 use core::any::Any;
 use core::mem;

src/libpanic_unwind/gcc.rs

@@ -36,8 +36,6 @@
 //! Once stack has been unwound down to the handler frame level, unwinding stops
 //! and the last personality routine transfers control to the catch block.
 
-#![allow(private_no_mangle_fns)]
-
 use alloc::boxed::Box;
 use core::any::Any;
 

src/libpanic_unwind/seh.rs

@@ -45,7 +45,6 @@
 //! [llvm]: http://llvm.org/docs/ExceptionHandling.html#background-on-windows-exceptions
 
 #![allow(nonstandard_style)]
-#![allow(private_no_mangle_fns)]
 
 use alloc::boxed::Box;
 use core::any::Any;

src/librustc_builtin_macros/proc_macro_harness.rs

@@ -59,7 +59,7 @@ pub fn inject(
     handler: &rustc_errors::Handler,
 ) -> ast::Crate {
     let ecfg = ExpansionConfig::default("proc_macro".to_string());
-    let mut cx = ExtCtxt::new(sess, ecfg, resolver);
+    let mut cx = ExtCtxt::new(sess, ecfg, resolver, None);
 
     let mut collect = CollectProcMacros {
         macros: Vec::new(),

src/librustc_builtin_macros/standard_library_imports.rs

@@ -39,7 +39,7 @@ pub fn inject(
     let call_site = DUMMY_SP.with_call_site_ctxt(expn_id);
 
     let ecfg = ExpansionConfig::default("std_lib_injection".to_string());
-    let cx = ExtCtxt::new(sess, ecfg, resolver);
+    let cx = ExtCtxt::new(sess, ecfg, resolver, None);
 
     // .rev() to preserve ordering above in combination with insert(0, ...)
     for &name in names.iter().rev() {

src/librustc_builtin_macros/test_harness.rs

@@ -202,7 +202,7 @@ fn generate_test_harness(
     let mut econfig = ExpansionConfig::default("test".to_string());
     econfig.features = Some(features);
 
-    let ext_cx = ExtCtxt::new(sess, econfig, resolver);
+    let ext_cx = ExtCtxt::new(sess, econfig, resolver, None);
 
     let expn_id = ext_cx.resolver.expansion_for_ast_pass(
         DUMMY_SP,

src/librustc_expand/base.rs

@@ -926,6 +926,8 @@ pub struct ExtCtxt<'a> {
     pub resolver: &'a mut dyn Resolver,
     pub current_expansion: ExpansionData,
     pub expansions: FxHashMap<Span, Vec<String>>,
+    /// Called directly after having parsed an external `mod foo;` in expansion.
+    pub(super) extern_mod_loaded: Option<&'a dyn Fn(&ast::Crate)>,
 }
 
 impl<'a> ExtCtxt<'a> {
@@ -933,12 +935,14 @@ impl<'a> ExtCtxt<'a> {
         parse_sess: &'a ParseSess,
         ecfg: expand::ExpansionConfig<'a>,
         resolver: &'a mut dyn Resolver,
+        extern_mod_loaded: Option<&'a dyn Fn(&ast::Crate)>,
     ) -> ExtCtxt<'a> {
         ExtCtxt {
             parse_sess,
             ecfg,
-            root_path: PathBuf::new(),
             resolver,
+            extern_mod_loaded,
+            root_path: PathBuf::new(),
             current_expansion: ExpansionData {
                 id: ExpnId::root(),
                 depth: 0,

src/librustc_expand/expand.rs

@@ -1457,8 +1457,19 @@ impl<'a, 'b> MutVisitor for InvocationCollector<'a, 'b> {
                     // We have an outline `mod foo;` so we need to parse the file.
                     let (new_mod, dir) =
                         parse_external_mod(sess, ident, span, dir, &mut attrs, pushed);
-                    *old_mod = new_mod;
-                    item.attrs = attrs;
+
+                    let krate = ast::Crate {
+                        span: new_mod.inner,
+                        module: new_mod,
+                        attrs,
+                        proc_macros: vec![],
+                    };
+                    if let Some(extern_mod_loaded) = self.cx.extern_mod_loaded {
+                        extern_mod_loaded(&krate);
+                    }
+
+                    *old_mod = krate.module;
+                    item.attrs = krate.attrs;
                     // File can have inline attributes, e.g., `#![cfg(...)]` & co. => Reconfigure.
                     item = match self.configure(item) {
                         Some(node) => node,

src/librustc_interface/passes.rs

@@ -210,14 +210,7 @@ pub fn register_plugins<'a>(
     Ok((krate, Lrc::new(lint_store)))
 }
 
-fn configure_and_expand_inner<'a>(
-    sess: &'a Session,
-    lint_store: &'a LintStore,
-    mut krate: ast::Crate,
-    crate_name: &str,
-    resolver_arenas: &'a ResolverArenas<'a>,
-    metadata_loader: &'a MetadataLoaderDyn,
-) -> Result<(ast::Crate, Resolver<'a>)> {
+fn pre_expansion_lint(sess: &Session, lint_store: &LintStore, krate: &ast::Crate) {
     sess.time("pre_AST_expansion_lint_checks", || {
         rustc_lint::check_ast_crate(
             sess,
@@ -228,6 +221,17 @@ fn configure_and_expand_inner<'a>(
             rustc_lint::BuiltinCombinedPreExpansionLintPass::new(),
         );
     });
+}
+
+fn configure_and_expand_inner<'a>(
+    sess: &'a Session,
+    lint_store: &'a LintStore,
+    mut krate: ast::Crate,
+    crate_name: &str,
+    resolver_arenas: &'a ResolverArenas<'a>,
+    metadata_loader: &'a MetadataLoaderDyn,
+) -> Result<(ast::Crate, Resolver<'a>)> {
+    pre_expansion_lint(sess, lint_store, &krate);
 
     let mut resolver = Resolver::new(sess, &krate, crate_name, metadata_loader, &resolver_arenas);
     rustc_builtin_macros::register_builtin_macros(&mut resolver, sess.edition());
@@ -291,7 +295,8 @@ fn configure_and_expand_inner<'a>(
             ..rustc_expand::expand::ExpansionConfig::default(crate_name.to_string())
         };
 
-        let mut ecx = ExtCtxt::new(&sess.parse_sess, cfg, &mut resolver);
+        let extern_mod_loaded = |k: &ast::Crate| pre_expansion_lint(sess, lint_store, k);
+        let mut ecx = ExtCtxt::new(&sess.parse_sess, cfg, &mut resolver, Some(&extern_mod_loaded));
 
         // Expand macros now!
         let krate = sess.time("expand_crate", || ecx.monotonic_expander().expand_crate(krate));

src/librustc_lint/early.rs

@@ -18,7 +18,7 @@ use crate::context::{EarlyContext, LintContext, LintStore};
 use crate::passes::{EarlyLintPass, EarlyLintPassObject};
 use rustc_ast::ast;
 use rustc_ast::visit as ast_visit;
-use rustc_session::lint::{LintBuffer, LintPass};
+use rustc_session::lint::{BufferedEarlyLint, LintBuffer, LintPass};
 use rustc_session::Session;
 use rustc_span::Span;
 
@@ -37,13 +37,7 @@ struct EarlyContextAndPass<'a, T: EarlyLintPass> {
 impl<'a, T: EarlyLintPass> EarlyContextAndPass<'a, T> {
     fn check_id(&mut self, id: ast::NodeId) {
         for early_lint in self.context.buffered.take(id) {
-            let rustc_session::lint::BufferedEarlyLint {
-                span,
-                msg,
-                node_id: _,
-                lint_id,
-                diagnostic,
-            } = early_lint;
+            let BufferedEarlyLint { span, msg, node_id: _, lint_id, diagnostic } = early_lint;
             self.context.lookup_with_diagnostics(
                 lint_id.lint,
                 Some(span),
@@ -326,11 +320,9 @@ pub fn check_ast_crate<T: EarlyLintPass>(
     lint_buffer: Option<LintBuffer>,
     builtin_lints: T,
 ) {
-    let mut passes: Vec<_> = if pre_expansion {
-        lint_store.pre_expansion_passes.iter().map(|p| (p)()).collect()
-    } else {
-        lint_store.early_passes.iter().map(|p| (p)()).collect()
-    };
+    let passes =
+        if pre_expansion { &lint_store.pre_expansion_passes } else { &lint_store.early_passes };
+    let mut passes: Vec<_> = passes.iter().map(|p| (p)()).collect();
     let mut buffered = lint_buffer.unwrap_or_default();
 
     if !sess.opts.debugging_opts.no_interleave_lints {

src/test/incremental/change_symbol_export_status.rs

@@ -2,10 +2,8 @@
 // compile-flags: -Zquery-dep-graph
 
 #![feature(rustc_attrs)]
-#![allow(private_no_mangle_fns)]
-
-#![rustc_partition_codegened(module="change_symbol_export_status-mod1", cfg="rpass2")]
-#![rustc_partition_reused(module="change_symbol_export_status-mod2", cfg="rpass2")]
+#![rustc_partition_codegened(module = "change_symbol_export_status-mod1", cfg = "rpass2")]
+#![rustc_partition_reused(module = "change_symbol_export_status-mod2", cfg = "rpass2")]
 
 // This test case makes sure that a change in symbol visibility is detected by
 // our dependency tracking. We do this by changing a module's visibility to

src/test/ui-fulldeps/auxiliary/linkage-visibility.rs

@@ -2,16 +2,14 @@
 
 #![feature(rustc_private)]
 
-// We're testing linkage visibility; the compiler warns us, but we want to
-// do the runtime check that these functions aren't exported.
-#![allow(private_no_mangle_fns)]
-
 extern crate rustc_metadata;
 
 use rustc_metadata::dynamic_lib::DynamicLibrary;
 
 #[no_mangle]
-pub fn foo() { bar(); }
+pub fn foo() {
+    bar();
+}
 
 pub fn foo2<T>() {
     fn bar2() {
@@ -21,11 +19,11 @@ pub fn foo2<T>() {
 }
 
 #[no_mangle]
-fn bar() { }
+fn bar() {}
 
 #[allow(dead_code)]
 #[no_mangle]
-fn baz() { }
+fn baz() {}
 
 pub fn test() {
     let lib = DynamicLibrary::open(None).unwrap();

src/test/ui/lint/lint-pre-expansion-extern-module.rs

@@ -0,0 +1,7 @@
+// check-pass
+// compile-flags: -W rust-2018-compatibility
+// error-pattern: `try` is a keyword in the 2018 edition
+
+fn main() {}
+
+mod lint_pre_expansion_extern_module_aux;

src/test/ui/lint/lint-pre-expansion-extern-module.stderr

@@ -0,0 +1,10 @@
+warning: `try` is a keyword in the 2018 edition
+  --> $DIR/lint_pre_expansion_extern_module_aux.rs:3:8
+   |
+LL | pub fn try() {}
+   |        ^^^ help: you can use a raw identifier to stay compatible: `r#try`
+   |
+   = note: `-W keyword-idents` implied by `-W rust-2018-compatibility`
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in the 2018 edition!
+   = note: for more information, see issue #49716 <https://github.com/rust-lang/rust/issues/49716>
+

src/test/ui/lint/lint_pre_expansion_extern_module_aux.rs

@@ -0,0 +1,3 @@
+// ignore-test: not a test
+
+pub fn try() {}