hide --explain hint if error has no extended info

src/librustc_errors/lib.rs

@@ -16,6 +16,7 @@ pub use emitter::ColorConfig;
 use Level::*;
 
 use emitter::{Emitter, EmitterWriter};
+use registry::Registry;
 
 use rustc_data_structures::sync::{self, Lrc, Lock, AtomicUsize, AtomicBool, SeqCst};
 use rustc_data_structures::fx::FxHashSet;
@@ -651,7 +652,7 @@ impl Handler {
         self.err_count() > 0
     }
 
-    pub fn print_error_count(&self) {
+    pub fn print_error_count(&self, registry: &Registry) {
         let s = match self.err_count() {
             0 => return,
             1 => "aborting due to previous error".to_string(),
@@ -666,19 +667,22 @@ impl Handler {
         let can_show_explain = self.emitter.borrow().should_show_explain();
         let are_there_diagnostics = !self.emitted_diagnostic_codes.borrow().is_empty();
         if can_show_explain && are_there_diagnostics {
-            let mut error_codes =
-                self.emitted_diagnostic_codes.borrow()
-                                             .iter()
-                                             .filter_map(|x| match *x {
-                                                 DiagnosticId::Error(ref s) => Some(s.clone()),
-                                                 _ => None,
-                                             })
-                                             .collect::<Vec<_>>();
+            let mut error_codes = self
+                .emitted_diagnostic_codes
+                .borrow()
+                .iter()
+                .filter_map(|x| match &x {
+                    DiagnosticId::Error(s) if registry.find_description(s).is_some() => {
+                        Some(s.clone())
+                    }
+                    _ => None,
+                })
+                .collect::<Vec<_>>();
             if !error_codes.is_empty() {
                 error_codes.sort();
                 if error_codes.len() > 1 {
                     let limit = if error_codes.len() > 9 { 9 } else { error_codes.len() };
-                    self.failure(&format!("Some errors occurred: {}{}",
+                    self.failure(&format!("Some errors have detailed explanations: {}{}",
                                           error_codes[..limit].join(", "),
                                           if error_codes.len() > 9 { "..." } else { "." }));
                     self.failure(&format!("For more information about an error, try \

src/librustc_interface/interface.rs

@@ -111,7 +111,9 @@ where
         crate_name: config.crate_name,
     };
 
-    let _sess_abort_error = OnDrop(|| compiler.sess.diagnostic().print_error_count());
+    let _sess_abort_error = OnDrop(|| {
+        compiler.sess.diagnostic().print_error_count(&util::diagnostics_registry());
+    });
 
     if compiler.sess.profile_queries() {
         profile::begin(&compiler.sess);

src/test/ui-fulldeps/hash-stable-is-unstable.stderr

@@ -49,5 +49,5 @@ LL | #[derive(HashStable)]
 
 error: aborting due to 6 previous errors
 
-Some errors occurred: E0601, E0658.
+Some errors have detailed explanations: E0601, E0658.
 For more information about an error, try `rustc --explain E0601`.

src/test/ui-fulldeps/macro-crate-rlib.stderr

@@ -6,4 +6,3 @@ LL | #![plugin(rlib_crate_test)]
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0457`.

src/test/ui/E0594.ast.nll.stderr

@@ -6,4 +6,3 @@ LL |     NUM = 20;
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0594`.

src/test/ui/E0594.ast.stderr

@@ -6,4 +6,3 @@ LL |     NUM = 20;
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0594`.

src/test/ui/E0594.mir.stderr

@@ -6,4 +6,3 @@ LL |     NUM = 20;
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0594`.

src/test/ui/E0660.stderr

@@ -12,4 +12,3 @@ LL |     asm!("nop" "nop" : "=r"(a));
 
 error: aborting due to 2 previous errors
 
-For more information about this error, try `rustc --explain E0660`.

src/test/ui/E0661.stderr

@@ -6,4 +6,3 @@ LL |     asm!("nop" : "r"(a));
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0661`.

src/test/ui/E0662.stderr

@@ -6,4 +6,3 @@ LL |          : "=test"("a")
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0662`.

src/test/ui/E0663.stderr

@@ -6,4 +6,3 @@ LL |          : "+test"("a")
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0663`.

src/test/ui/E0664.stderr

@@ -6,4 +6,3 @@ LL |          : "{eax}"
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0664`.

src/test/ui/E0665.stderr

@@ -6,4 +6,3 @@ LL | #[derive(Default)]
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0665`.

src/test/ui/anonymous-higher-ranked-lifetime.stderr

@@ -308,4 +308,3 @@ LL | fn h2<F>(_: F) where F: for<'t0> Fn(&(), Box<Fn(&())>, &'t0 (), fn(&(), &()
 
 error: aborting due to 22 previous errors
 
-For more information about this error, try `rustc --explain E0631`.

src/test/ui/asm/asm-bad-clobber.stderr

@@ -6,4 +6,3 @@ LL |         asm!("xor %eax, %eax" : : : "{eax}");
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0664`.

src/test/ui/asm/asm-in-bad-modifier.stderr

@@ -12,5 +12,3 @@ LL |         asm!("mov $1, $0" : "=r"(y) : "+r"(5));
 
 error: aborting due to 2 previous errors
 
-Some errors occurred: E0662, E0663.
-For more information about an error, try `rustc --explain E0662`.

src/test/ui/asm/asm-out-no-modifier.stderr

@@ -6,4 +6,3 @@ LL |         asm!("mov $1, $0" : "r"(x) : "r"(5));
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0661`.

src/test/ui/associated-path-shl.stderr

@@ -39,5 +39,5 @@ LL |     let 0 ..= <<A>::B>::C;
 
 error: aborting due to 6 previous errors
 
-Some errors occurred: E0029, E0412.
+Some errors have detailed explanations: E0029, E0412.
 For more information about an error, try `rustc --explain E0029`.

src/test/ui/associated-type/associated-type-projection-from-multiple-supertraits.stderr

@@ -45,5 +45,5 @@ LL | fn paint<C:BoxCar>(c: C, d: C::Color) {
 
 error: aborting due to 4 previous errors
 
-Some errors occurred: E0191, E0221.
+Some errors have detailed explanations: E0191, E0221.
 For more information about an error, try `rustc --explain E0191`.

src/test/ui/associated-types/associated-types-eq-3.stderr

@@ -33,5 +33,5 @@ LL |     baz(&a);
 
 error: aborting due to 3 previous errors
 
-Some errors occurred: E0271, E0308.
+Some errors have detailed explanations: E0271, E0308.
 For more information about an error, try `rustc --explain E0271`.

src/test/ui/associated-types/associated-types-eq-hr.stderr

@@ -122,5 +122,5 @@ LL | | }
 
 error: aborting due to 7 previous errors
 
-Some errors occurred: E0271, E0277.
+Some errors have detailed explanations: E0271, E0277.
 For more information about an error, try `rustc --explain E0271`.

src/test/ui/associated-types/associated-types-overridden-binding.stderr

@@ -12,4 +12,3 @@ LL | trait Foo: Iterator<Item = i32> {}
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0284`.

src/test/ui/associated-types/associated-types-path-1.stderr

@@ -18,5 +18,5 @@ LL | pub fn f2<T: Foo + Bar>(a: T, x: T::A) {}
 
 error: aborting due to 2 previous errors
 
-Some errors occurred: E0220, E0221.
+Some errors have detailed explanations: E0220, E0221.
 For more information about an error, try `rustc --explain E0220`.

src/test/ui/associated-types/associated-types-path-2.stderr

@@ -48,5 +48,5 @@ LL |     let _: i32 = f2(2i32);
 
 error: aborting due to 6 previous errors
 
-Some errors occurred: E0277, E0308.
+Some errors have detailed explanations: E0277, E0308.
 For more information about an error, try `rustc --explain E0277`.

src/test/ui/associated-types/associated-types-project-from-hrtb-in-fn-body.stderr

@@ -11,4 +11,3 @@ LL |     let z: I::A = if cond { x } else { y };
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0623`.

src/test/ui/associated-types/associated-types-project-from-hrtb-in-fn.stderr

@@ -6,4 +6,3 @@ LL |     x: I::A)
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0212`.

src/test/ui/associated-types/associated-types-project-from-hrtb-in-struct.stderr

@@ -6,4 +6,3 @@ LL |     field: I::A
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0212`.

src/test/ui/associated-types/associated-types-project-from-hrtb-in-trait-method.stderr

@@ -6,4 +6,3 @@ LL |     fn some_method(&self, arg: I::A);
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0212`.

src/test/ui/associated-types/associated-types-subtyping-1.stderr

@@ -18,4 +18,3 @@ LL |     let _c: <T as Trait<'a>>::Type = b;
 
 error: aborting due to 2 previous errors
 
-For more information about this error, try `rustc --explain E0623`.

src/test/ui/associated-types/associated-types-unconstrained.stderr

@@ -6,4 +6,3 @@ LL |     let x: isize = Foo::bar();
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0284`.

src/test/ui/associated-types/cache/project-fn-ret-contravariant.krisskross.stderr

@@ -22,4 +22,3 @@ LL |    (a, b)
 
 error: aborting due to 2 previous errors
 
-For more information about this error, try `rustc --explain E0623`.

src/test/ui/associated-types/cache/project-fn-ret-contravariant.transmute.stderr

@@ -23,4 +23,3 @@ LL |    bar(foo, x)
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0495`.

src/test/ui/associated-types/cache/project-fn-ret-invariant.krisskross.stderr

@@ -21,4 +21,3 @@ LL |    let b = bar(foo, x);
 
 error: aborting due to 2 previous errors
 
-For more information about this error, try `rustc --explain E0623`.

src/test/ui/associated-types/cache/project-fn-ret-invariant.oneuse.stderr

@@ -11,4 +11,3 @@ LL |    let b = bar(f, y);
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0623`.

src/test/ui/associated-types/cache/project-fn-ret-invariant.transmute.stderr

@@ -19,4 +19,3 @@ LL | fn baz<'a,'b>(x: Type<'a>) -> Type<'static> {
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0495`.

src/test/ui/augmented-assignments.nll.stderr

@@ -18,5 +18,5 @@ LL |     y
 
 error: aborting due to 2 previous errors
 
-Some errors occurred: E0505, E0596.
+Some errors have detailed explanations: E0505, E0596.
 For more information about an error, try `rustc --explain E0505`.

src/test/ui/augmented-assignments.stderr

@@ -20,5 +20,5 @@ LL |     x;
 
 error: aborting due to 2 previous errors
 
-Some errors occurred: E0382, E0596.
+Some errors have detailed explanations: E0382, E0596.
 For more information about an error, try `rustc --explain E0382`.

src/test/ui/auto-trait-validation.stderr

@@ -18,5 +18,4 @@ LL | auto trait MyTrait { fn foo() {} }
 
 error: aborting due to 3 previous errors
 
-Some errors occurred: E0380, E0567, E0568.
-For more information about an error, try `rustc --explain E0380`.
+For more information about this error, try `rustc --explain E0380`.

src/test/ui/await-keyword/2018-edition-error.stderr

@@ -36,4 +36,3 @@ LL |     match await { await => () }
 
 error: aborting due to 6 previous errors
 
-For more information about this error, try `rustc --explain E0721`.

src/test/ui/await-keyword/post_expansion_error.stderr

@@ -6,4 +6,3 @@ LL |     await!()
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0721`.

src/test/ui/bad/bad-env-capture.stderr

@@ -20,5 +20,5 @@ LL |     fn bar() { log(debug, x); }
 
 error: aborting due to 3 previous errors
 
-Some errors occurred: E0425, E0434.
+Some errors have detailed explanations: E0425, E0434.
 For more information about an error, try `rustc --explain E0425`.

src/test/ui/bad/bad-env-capture2.stderr

@@ -20,5 +20,5 @@ LL |     fn bar() { log(debug, x); }
 
 error: aborting due to 3 previous errors
 
-Some errors occurred: E0425, E0434.
+Some errors have detailed explanations: E0425, E0434.
 For more information about an error, try `rustc --explain E0425`.

src/test/ui/bad/bad-env-capture3.stderr

@@ -20,5 +20,5 @@ LL |         fn bar() { log(debug, x); }
 
 error: aborting due to 3 previous errors
 
-Some errors occurred: E0425, E0434.
+Some errors have detailed explanations: E0425, E0434.
 For more information about an error, try `rustc --explain E0425`.

src/test/ui/bad/bad-expr-lhs.stderr

@@ -30,5 +30,5 @@ LL |     None = Some(3);
 
 error: aborting due to 5 previous errors
 
-Some errors occurred: E0067, E0070.
+Some errors have detailed explanations: E0067, E0070.
 For more information about an error, try `rustc --explain E0067`.

src/test/ui/bad/bad-expr-path.stderr

@@ -27,5 +27,5 @@ LL | fn main(arguments: Vec<String>) {
 
 error: aborting due to 4 previous errors
 
-Some errors occurred: E0425, E0580.
+Some errors have detailed explanations: E0425, E0580.
 For more information about an error, try `rustc --explain E0425`.

src/test/ui/bad/bad-expr-path2.stderr

@@ -27,5 +27,5 @@ LL | fn main(arguments: Vec<String>) {
 
 error: aborting due to 4 previous errors
 
-Some errors occurred: E0423, E0425, E0580.
+Some errors have detailed explanations: E0423, E0425, E0580.
 For more information about an error, try `rustc --explain E0423`.

src/test/ui/bad/bad-extern-link-attrs.stderr

@@ -20,5 +20,5 @@ LL | #[link(name = "foo", kind = "bar")]
 
 error: aborting due to 3 previous errors
 
-Some errors occurred: E0454, E0458, E0459.
+Some errors have detailed explanations: E0454, E0458, E0459.
 For more information about an error, try `rustc --explain E0454`.

src/test/ui/bad/bad-intrinsic-monomorphization.stderr

@@ -18,4 +18,3 @@ LL |     simd_add(a, b)
 
 error: aborting due to 3 previous errors
 
-For more information about this error, try `rustc --explain E0511`.

src/test/ui/bad/bad-sized.stderr

@@ -26,5 +26,5 @@ LL |     let x: Vec<Trait + Sized> = Vec::new();
 
 error: aborting due to 3 previous errors
 
-Some errors occurred: E0225, E0277.
+Some errors have detailed explanations: E0225, E0277.
 For more information about an error, try `rustc --explain E0225`.

src/test/ui/binop/binop-move-semantics.nll.stderr

@@ -91,5 +91,5 @@ LL | |     &mut f;
 
 error: aborting due to 8 previous errors
 
-Some errors occurred: E0382, E0502, E0505, E0507.
+Some errors have detailed explanations: E0382, E0502, E0505, E0507.
 For more information about an error, try `rustc --explain E0382`.

src/test/ui/binop/binop-move-semantics.stderr

@@ -76,5 +76,5 @@ LL |     &mut f;
 
 error: aborting due to 8 previous errors
 
-Some errors occurred: E0382, E0502, E0505, E0507.
+Some errors have detailed explanations: E0382, E0502, E0505, E0507.
 For more information about an error, try `rustc --explain E0382`.

src/test/ui/block-result/issue-20862.stderr

@@ -25,5 +25,5 @@ LL |       let x = foo(5)(2);
 
 error: aborting due to 2 previous errors
 
-Some errors occurred: E0308, E0618.
+Some errors have detailed explanations: E0308, E0618.
 For more information about an error, try `rustc --explain E0308`.

src/test/ui/block-result/issue-22645.stderr

@@ -22,5 +22,5 @@ LL |   b + 3
 
 error: aborting due to 2 previous errors
 
-Some errors occurred: E0277, E0308.
+Some errors have detailed explanations: E0277, E0308.
 For more information about an error, try `rustc --explain E0277`.

src/test/ui/borrowck/borrow-immutable-upvar-mutation.nll.stderr

@@ -72,5 +72,4 @@ LL |         let _h = to_fn_mut(move || { set(&mut z); to_fn(move || z = 42); })
 
 error: aborting due to 6 previous errors
 
-Some errors occurred: E0594, E0596.
-For more information about an error, try `rustc --explain E0594`.
+For more information about this error, try `rustc --explain E0596`.

src/test/ui/borrowck/borrow-immutable-upvar-mutation.stderr

@@ -74,5 +74,5 @@ LL |         let _h = to_fn_mut(move || { set(&mut z); to_fn(move || z = 42); })
 
 error: aborting due to 6 previous errors
 
-Some errors occurred: E0387, E0594, E0596.
+Some errors have detailed explanations: E0387, E0596.
 For more information about an error, try `rustc --explain E0387`.

src/test/ui/borrowck/borrow-tuple-fields.nll.stderr

@@ -61,5 +61,5 @@ LL |     a.use_mut();
 
 error: aborting due to 6 previous errors
 
-Some errors occurred: E0499, E0502, E0505.
+Some errors have detailed explanations: E0499, E0502, E0505.
 For more information about an error, try `rustc --explain E0499`.

src/test/ui/borrowck/borrow-tuple-fields.stderr

@@ -60,5 +60,5 @@ LL | }
 
 error: aborting due to 6 previous errors
 
-Some errors occurred: E0499, E0502, E0505.
+Some errors have detailed explanations: E0499, E0502, E0505.
 For more information about an error, try `rustc --explain E0499`.

src/test/ui/borrowck/borrowck-access-permissions.ast.stderr

@@ -42,5 +42,5 @@ LL |         let _y = &mut *foo_ref.f;
 
 error: aborting due to 6 previous errors
 
-Some errors occurred: E0389, E0596.
+Some errors have detailed explanations: E0389, E0596.
 For more information about an error, try `rustc --explain E0389`.