rustc: Add some more checks to the stability lint

src/librustc/lint/builtin.rs

@@ -45,7 +45,7 @@ use syntax::ast_map;
 use syntax::ast_util::is_shift_binop;
 use syntax::attr::AttrMetaMethods;
 use syntax::attr;
-use syntax::codemap::Span;
+use syntax::codemap::{Span, DUMMY_SP};
 use syntax::parse::token;
 use syntax::{ast, ast_util, visit};
 use syntax::ast::{TyI, TyU, TyI8, TyU8, TyI16, TyU16, TyI32, TyU32, TyI64, TyU64};
@@ -1553,16 +1553,40 @@ declare_lint!(UNSTABLE, Allow,
 /// `#[unstable]` attributes, or no stability attribute.
 pub struct Stability;
 
-impl LintPass for Stability {
-    fn get_lints(&self) -> LintArray {
-        lint_array!(DEPRECATED, EXPERIMENTAL, UNSTABLE)
+impl Stability {
+    fn lint(&self, cx: &Context, id: ast::DefId, span: Span) {
+        let stability = stability::lookup(cx.tcx, id);
+        let cross_crate = !ast_util::is_local(id);
+
+        // stability attributes are promises made across crates; only
+        // check DEPRECATED for crate-local usage.
+        let (lint, label) = match stability {
+            // no stability attributes == Unstable
+            None if cross_crate => (UNSTABLE, "unmarked"),
+            Some(attr::Stability { level: attr::Unstable, .. }) if cross_crate =>
+                (UNSTABLE, "unstable"),
+            Some(attr::Stability { level: attr::Experimental, .. }) if cross_crate =>
+                (EXPERIMENTAL, "experimental"),
+            Some(attr::Stability { level: attr::Deprecated, .. }) =>
+                (DEPRECATED, "deprecated"),
+            _ => return
+        };
+
+        let msg = match stability {
+            Some(attr::Stability { text: Some(ref s), .. }) => {
+                format!("use of {} item: {}", label, *s)
+            }
+            _ => format!("use of {} item", label)
+        };
+
+        cx.span_lint(lint, span, msg.as_slice());
     }
 
-    fn check_expr(&mut self, cx: &Context, e: &ast::Expr) {
+    fn is_internal(&self, cx: &Context, span: Span) -> bool {
         // first, check if the given expression was generated by a macro or not
         // we need to go back the expn_info tree to check only the arguments
         // of the initial macro call, not the nested ones.
-        let mut expnid = e.span.expn_id;
+        let mut expnid = span.expn_id;
         let mut is_internal = false;
         while cx.tcx.sess.codemap().with_expn_info(expnid, |expninfo| {
             match expninfo {
@@ -1577,15 +1601,41 @@ impl LintPass for Stability {
                         true // continue looping
                     } else {
                         // was this expression from the current macro arguments ?
-                        is_internal = !( e.span.lo > info.call_site.lo &&
-                                         e.span.hi < info.call_site.hi );
+                        is_internal = !( span.lo > info.call_site.lo &&
+                                         span.hi < info.call_site.hi );
                         true // continue looping
                     }
                 },
                 _ => false // stop looping
             }
         }) { /* empty while loop body */ }
-        if is_internal { return; }
+        return is_internal;
+    }
+}
+
+impl LintPass for Stability {
+    fn get_lints(&self) -> LintArray {
+        lint_array!(DEPRECATED, EXPERIMENTAL, UNSTABLE)
+    }
+
+    fn check_view_item(&mut self, cx: &Context, item: &ast::ViewItem) {
+        // compiler-generated `extern crate` statements have a dummy span.
+        if item.span == DUMMY_SP { return }
+
+        let id = match item.node {
+            ast::ViewItemExternCrate(_, _, id) => id,
+            ast::ViewItemUse(..) => return,
+        };
+        let cnum = match cx.tcx.sess.cstore.find_extern_mod_stmt_cnum(id) {
+            Some(cnum) => cnum,
+            None => return,
+        };
+        let id = ast::DefId { krate: cnum, node: ast::CRATE_NODE_ID };
+        self.lint(cx, id, item.span);
+    }
+
+    fn check_expr(&mut self, cx: &Context, e: &ast::Expr) {
+        if self.is_internal(cx, e.span) { return; }
 
         let mut span = e.span;
 
@@ -1629,32 +1679,30 @@ impl LintPass for Stability {
             }
             _ => return
         };
+        self.lint(cx, id, span);
+    }
 
-        let stability = stability::lookup(cx.tcx, id);
-        let cross_crate = !ast_util::is_local(id);
-
-        // stability attributes are promises made across crates; only
-        // check DEPRECATED for crate-local usage.
-        let (lint, label) = match stability {
-            // no stability attributes == Unstable
-            None if cross_crate => (UNSTABLE, "unmarked"),
-            Some(attr::Stability { level: attr::Unstable, .. }) if cross_crate =>
-                (UNSTABLE, "unstable"),
-            Some(attr::Stability { level: attr::Experimental, .. }) if cross_crate =>
-                (EXPERIMENTAL, "experimental"),
-            Some(attr::Stability { level: attr::Deprecated, .. }) =>
-                (DEPRECATED, "deprecated"),
-            _ => return
-        };
+    fn check_item(&mut self, cx: &Context, item: &ast::Item) {
+        if self.is_internal(cx, item.span) { return }
 
-        let msg = match stability {
-            Some(attr::Stability { text: Some(ref s), .. }) => {
-                format!("use of {} item: {}", label, *s)
+        match item.node {
+            ast::ItemTrait(_, _, ref supertraits, _) => {
+                for t in supertraits.iter() {
+                    match *t {
+                        ast::TraitTyParamBound(ref t) => {
+                            let id = ty::trait_ref_to_def_id(cx.tcx, t);
+                            self.lint(cx, id, t.path.span);
+                        }
+                        _ => (/* pass */)
+                    }
+                }
             }
-            _ => format!("use of {} item", label)
-        };
-
-        cx.span_lint(lint, span, msg.as_slice());
+            ast::ItemImpl(_, Some(ref t), _, _) => {
+                let id = ty::trait_ref_to_def_id(cx.tcx, t);
+                self.lint(cx, id, t.path.span);
+            }
+            _ => (/* pass */)
+        }
     }
 }
 

src/test/auxiliary/lint_stability.rs

@@ -118,6 +118,9 @@ pub trait Trait {
 
 impl Trait for MethodTester {}
 
+#[experimental]
+pub trait ExperimentalTrait {}
+
 #[deprecated]
 pub struct DeprecatedStruct { pub i: int }
 #[experimental]

src/test/compile-fail/lint-output-format.rs

@@ -11,7 +11,7 @@
 // compile-flags:-F experimental -D unstable
 // aux-build:lint_output_format.rs
 
-extern crate lint_output_format;
+extern crate lint_output_format; //~ ERROR: use of unmarked item
 use lint_output_format::{foo, bar, baz};
 
 fn main() {

src/test/compile-fail/lint-stability.rs

@@ -19,7 +19,7 @@
 
 mod cross_crate {
     #[phase(plugin, link)]
-    extern crate lint_stability;
+    extern crate lint_stability; //~ ERROR: use of unmarked item
     use self::lint_stability::*;
 
     fn test() {
@@ -141,10 +141,16 @@ mod cross_crate {
         foo.trait_unmarked(); //~ ERROR use of unmarked item
         foo.trait_stable();
     }
+
+    struct S;
+
+    impl ExperimentalTrait for S { } //~ ERROR use of experimental item
+
+    trait LocalTrait : ExperimentalTrait { } //~ ERROR use of experimental item
 }
 
 mod inheritance {
-    extern crate inherited_stability;
+    extern crate inherited_stability; //~ ERROR: use of experimental item
     use self::inherited_stability::*;
 
     fn test_inheritance() {
@@ -444,6 +450,15 @@ mod this_crate {
         foo.trait_unmarked();
         foo.trait_stable();
     }
+
+    #[deprecated]
+    pub trait DeprecatedTrait {}
+
+    struct S;
+
+    impl DeprecatedTrait for S { } //~ ERROR use of deprecated item
+
+    trait LocalTrait : DeprecatedTrait { } //~ ERROR use of deprecated item
 }
 
 fn main() {}