resolve: Use standard stability diagnostics for macros

src/librustc/middle/stability.rs

@@ -477,6 +477,36 @@ pub fn provide(providers: &mut Providers<'_>) {
     };
 }
 
+pub fn report_unstable(
+    sess: &Session, feature: Symbol, reason: Option<Symbol>, issue: u32, span: Span
+) {
+    let msg = match reason {
+        Some(r) => format!("use of unstable library feature '{}': {}", feature, r),
+        None => format!("use of unstable library feature '{}'", &feature)
+    };
+
+    let msp: MultiSpan = span.into();
+    let cm = &sess.parse_sess.source_map();
+    let span_key = msp.primary_span().and_then(|sp: Span|
+        if !sp.is_dummy() {
+            let file = cm.lookup_char_pos(sp.lo()).file;
+            if file.name.is_macros() {
+                None
+            } else {
+                Some(span)
+            }
+        } else {
+            None
+        }
+    );
+
+    let error_id = (DiagnosticMessageId::StabilityId(issue), span_key, msg.clone());
+    let fresh = sess.one_time_diagnostics.borrow_mut().insert(error_id);
+    if fresh {
+        emit_feature_err(&sess.parse_sess, feature, span, GateIssue::Library(Some(issue)), &msg);
+    }
+}
+
 /// Checks whether an item marked with `deprecated(since="X")` is currently
 /// deprecated (i.e., whether X is not greater than the current rustc version).
 pub fn deprecation_in_effect(since: &str) -> bool {
@@ -715,34 +745,8 @@ impl<'tcx> TyCtxt<'tcx> {
     pub fn check_stability(self, def_id: DefId, id: Option<HirId>, span: Span) {
         match self.eval_stability(def_id, id, span) {
             EvalResult::Allow => {}
-            EvalResult::Deny { feature, reason, issue } => {
-                let msg = match reason {
-                    Some(r) => format!("use of unstable library feature '{}': {}", feature, r),
-                    None => format!("use of unstable library feature '{}'", &feature)
-                };
-
-                let msp: MultiSpan = span.into();
-                let cm = &self.sess.parse_sess.source_map();
-                let span_key = msp.primary_span().and_then(|sp: Span|
-                    if !sp.is_dummy() {
-                        let file = cm.lookup_char_pos(sp.lo()).file;
-                        if file.name.is_macros() {
-                            None
-                        } else {
-                            Some(span)
-                        }
-                    } else {
-                        None
-                    }
-                );
-
-                let error_id = (DiagnosticMessageId::StabilityId(issue), span_key, msg.clone());
-                let fresh = self.sess.one_time_diagnostics.borrow_mut().insert(error_id);
-                if fresh {
-                    emit_feature_err(&self.sess.parse_sess, feature, span,
-                                     GateIssue::Library(Some(issue)), &msg);
-                }
-            }
+            EvalResult::Deny { feature, reason, issue } =>
+                report_unstable(self.sess, feature, reason, issue, span),
             EvalResult::Unmarked => {
                 // The API could be uncallable for other reasons, for example when a private module
                 // was referenced.

src/librustc_resolve/macros.rs

@@ -9,6 +9,7 @@ use crate::resolve_imports::ImportResolver;
 use rustc::hir::def_id::{CrateNum, DefId, DefIndex, CRATE_DEF_INDEX};
 use rustc::hir::def::{self, DefKind, NonMacroAttrKind};
 use rustc::hir::map::{self, DefCollector};
+use rustc::middle::stability;
 use rustc::{ty, lint, span_bug};
 use syntax::ast::{self, Ident};
 use syntax::attr::{self, StabilityLevel};
@@ -18,7 +19,7 @@ use syntax::ext::base::{MacroKind, SyntaxExtension};
 use syntax::ext::expand::{AstFragment, Invocation, InvocationKind};
 use syntax::ext::hygiene::Mark;
 use syntax::ext::tt::macro_rules;
-use syntax::feature_gate::{feature_err, emit_feature_err, is_builtin_attr_name};
+use syntax::feature_gate::{feature_err, is_builtin_attr_name};
 use syntax::feature_gate::{AttributeGate, GateIssue, Stability, BUILTIN_ATTRIBUTES};
 use syntax::symbol::{Symbol, kw, sym};
 use syntax::visit::Visitor;
@@ -237,13 +238,11 @@ impl<'a> base::Resolver for Resolver<'a> {
         invoc.expansion_data.mark.set_expn_info(ext.expn_info(span, &format));
 
         if let Some(stability) = ext.stability {
-            if let StabilityLevel::Unstable { issue, .. } = stability.level {
-                let features = self.session.features_untracked();
-                if !span.allows_unstable(stability.feature) &&
-                   features.declared_lib_features.iter().all(|(feat, _)| *feat != stability.feature) {
-                    let msg = format!("macro {}! is unstable", path);
-                    emit_feature_err(&self.session.parse_sess, stability.feature, span,
-                                     GateIssue::Library(Some(issue)), &msg);
+            if let StabilityLevel::Unstable { reason, issue } = stability.level {
+                let (feature, features) = (stability.feature, self.session.features_untracked());
+                if !span.allows_unstable(feature) &&
+                   features.declared_lib_features.iter().all(|(feat, _)| *feat != feature) {
+                    stability::report_unstable(self.session, feature, reason, issue, span);
                 }
             }
         }

src/test/ui/macros/macro-stability.rs

@@ -7,6 +7,6 @@
 macro_rules! local_unstable { () => () }
 
 fn main() {
-    local_unstable!(); //~ ERROR: macro local_unstable! is unstable
-    unstable_macro!(); //~ ERROR: macro unstable_macro! is unstable
+    local_unstable!(); //~ ERROR use of unstable library feature 'local_unstable'
+    unstable_macro!(); //~ ERROR use of unstable library feature 'unstable_macros'
 }

src/test/ui/macros/macro-stability.stderr

@@ -1,12 +1,12 @@
-error[E0658]: macro local_unstable! is unstable
+error[E0658]: use of unstable library feature 'local_unstable'
   --> $DIR/macro-stability.rs:10:5
    |
 LL |     local_unstable!();
    |     ^^^^^^^^^^^^^^^^^^
    |
    = help: add #![feature(local_unstable)] to the crate attributes to enable
 
-error[E0658]: macro unstable_macro! is unstable
+error[E0658]: use of unstable library feature 'unstable_macros'
   --> $DIR/macro-stability.rs:11:5
    |
 LL |     unstable_macro!();