Rollup merge of #70038 - DutchGhost:const-forget-tests, r=RalfJung

[rust.git] / src / librustc_expand / base.rs

diff --git a/src/librustc_expand/base.rs b/src/librustc_expand/base.rs
index f15e626c2783b0593cd596de1bf4aad828bcea4e..74c304c96b9a45490d82dd6969abdc801c6580da 100644 (file)
--- a/src/librustc_expand/base.rs
+++ b/src/librustc_expand/base.rs
@@ -1,4 +1,5 @@
 use crate::expand::{self, AstFragment, Invocation};
+use crate::module::DirectoryOwnership;
 
 use rustc_ast::ast::{self, Attribute, Name, NodeId, PatKind};
 use rustc_ast::mut_visit::{self, MutVisitor};
@@ -10,7 +11,7 @@
 use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::sync::{self, Lrc};
 use rustc_errors::{DiagnosticBuilder, DiagnosticId};
-use rustc_parse::{self, parser, DirectoryOwnership, MACRO_ARGUMENTS};
+use rustc_parse::{self, parser, MACRO_ARGUMENTS};
 use rustc_session::parse::ParseSess;
 use rustc_span::edition::Edition;
 use rustc_span::hygiene::{AstPass, ExpnData, ExpnId, ExpnKind};
@@ -258,8 +259,17 @@ pub fn derive_allowed(&self) -> bool {
     }
 }
 
-// `meta_item` is the annotation, and `item` is the item being modified.
-// FIXME Decorators should follow the same pattern too.
+/// Result of an expansion that may need to be retried.
+/// Consider using this for non-`MultiItemModifier` expanders as well.
+pub enum ExpandResult<T, U> {
+    /// Expansion produced a result (possibly dummy).
+    Ready(T),
+    /// Expansion could not produce a result and needs to be retried.
+    /// The string is an explanation that will be printed if we are stuck in an infinite retry loop.
+    Retry(U, String),
+}
+
+// `meta_item` is the attribute, and `item` is the item being modified.
 pub trait MultiItemModifier {
     fn expand(
         &self,
@@ -267,13 +277,12 @@ fn expand(
         span: Span,
         meta_item: &ast::MetaItem,
         item: Annotatable,
-    ) -> Vec<Annotatable>;
+    ) -> ExpandResult<Vec<Annotatable>, Annotatable>;
 }
 
-impl<F, T> MultiItemModifier for F
+impl<F> MultiItemModifier for F
 where
-    F: Fn(&mut ExtCtxt<'_>, Span, &ast::MetaItem, Annotatable) -> T,
-    T: Into<Vec<Annotatable>>,
+    F: Fn(&mut ExtCtxt<'_>, Span, &ast::MetaItem, Annotatable) -> Vec<Annotatable>,
 {
     fn expand(
         &self,
@@ -281,14 +290,8 @@ fn expand(
         span: Span,
         meta_item: &ast::MetaItem,
         item: Annotatable,
-    ) -> Vec<Annotatable> {
-        (*self)(ecx, span, meta_item, item).into()
-    }
-}
-
-impl Into<Vec<Annotatable>> for Annotatable {
-    fn into(self) -> Vec<Annotatable> {
-        vec![self]
+    ) -> ExpandResult<Vec<Annotatable>, Annotatable> {
+        ExpandResult::Ready(self(ecx, span, meta_item, item))
     }
 }
 
@@ -372,7 +375,7 @@ fn visit_tt(&mut self, tt: &mut tokenstream::TokenTree) {
                 mut_visit::noop_visit_tt(tt, self)
             }
 
-            fn visit_mac(&mut self, mac: &mut ast::Mac) {
+            fn visit_mac(&mut self, mac: &mut ast::MacCall) {
                 mut_visit::noop_visit_mac(mac, self)
             }
         }
@@ -895,6 +898,7 @@ fn resolve_macro_invocation(
 
     fn has_derive_copy(&self, expn_id: ExpnId) -> bool;
     fn add_derive_copy(&mut self, expn_id: ExpnId);
+    fn cfg_accessible(&mut self, expn_id: ExpnId, path: &ast::Path) -> Result<bool, Indeterminate>;
 }
 
 #[derive(Clone)]
@@ -922,6 +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> {
@@ -929,12 +935,14 @@ pub fn new(
         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,