revert #48337 (--explain usage note)

src/librustc_errors/emitter.rs

@@ -21,7 +21,7 @@ use std::io::prelude::*;
 use std::io;
 use std::rc::Rc;
 use term;
-use std::collections::{HashMap, HashSet};
+use std::collections::HashMap;
 use std::cmp::min;
 use unicode_width;
 
@@ -109,7 +109,6 @@ pub struct EmitterWriter {
     cm: Option<Rc<CodeMapper>>,
     short_message: bool,
     teach: bool,
-    error_codes: HashSet<String>,
     ui_testing: bool,
 }
 
@@ -119,33 +118,6 @@ struct FileWithAnnotatedLines {
     multiline_depth: usize,
 }
 
-impl Drop for EmitterWriter {
-    fn drop(&mut self) {
-        if !self.short_message && !self.error_codes.is_empty() {
-            let mut error_codes = self.error_codes.clone().into_iter().collect::<Vec<_>>();
-            error_codes.sort();
-            if error_codes.len() > 1 {
-                let limit = if error_codes.len() > 9 { 9 } else { error_codes.len() };
-                writeln!(self.dst,
-                         "You've got a few errors: {}{}",
-                         error_codes[..limit].join(", "),
-                         if error_codes.len() > 9 { "..." } else { "" }
-                        ).expect("failed to give tips...");
-                writeln!(self.dst,
-                         "If you want more information on an error, try using \
-                          \"rustc --explain {}\"",
-                         &error_codes[0]).expect("failed to give tips...");
-            } else {
-                writeln!(self.dst,
-                         "If you want more information on this error, try using \
-                          \"rustc --explain {}\"",
-                         &error_codes[0]).expect("failed to give tips...");
-            }
-            self.dst.flush().expect("failed to emit errors");
-        }
-    }
-}
-
 impl EmitterWriter {
     pub fn stderr(color_config: ColorConfig,
                   code_map: Option<Rc<CodeMapper>>,
@@ -159,7 +131,6 @@ impl EmitterWriter {
                 cm: code_map,
                 short_message,
                 teach,
-                error_codes: HashSet::new(),
                 ui_testing: false,
             }
         } else {
@@ -168,7 +139,6 @@ impl EmitterWriter {
                 cm: code_map,
                 short_message,
                 teach,
-                error_codes: HashSet::new(),
                 ui_testing: false,
             }
         }
@@ -184,7 +154,6 @@ impl EmitterWriter {
             cm: code_map,
             short_message,
             teach,
-            error_codes: HashSet::new(),
             ui_testing: false,
         }
     }
@@ -1025,14 +994,12 @@ impl EmitterWriter {
             if primary_span != &&DUMMY_SP {
                 (cm.lookup_char_pos(primary_span.lo()), cm)
             } else {
-                emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message,
-                                    &mut self.error_codes)?;
+                emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
                 return Ok(());
             }
         } else {
             // If we don't have span information, emit and exit
-            emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message,
-                                &mut self.error_codes)?;
+            emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
             return Ok(());
         };
         if let Ok(pos) =
@@ -1205,8 +1172,7 @@ impl EmitterWriter {
         }
 
         // final step: take our styled buffer, render it, then output it
-        emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message,
-                            &mut self.error_codes)?;
+        emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
 
         Ok(())
 
@@ -1294,8 +1260,7 @@ impl EmitterWriter {
                 let msg = format!("and {} other candidates", suggestions.len() - MAX_SUGGESTIONS);
                 buffer.puts(row_num, 0, &msg, Style::NoStyle);
             }
-            emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message,
-                                &mut self.error_codes)?;
+            emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
         }
         Ok(())
     }
@@ -1326,7 +1291,7 @@ impl EmitterWriter {
                         draw_col_separator_no_space(&mut buffer, 0, max_line_num_len + 1);
                     }
                     match emit_to_destination(&buffer.render(), level, &mut self.dst,
-                                              self.short_message, &mut self.error_codes) {
+                                              self.short_message) {
                         Ok(()) => (),
                         Err(e) => panic!("failed to emit error: {}", e)
                     }
@@ -1419,8 +1384,7 @@ fn overlaps(a1: &Annotation, a2: &Annotation, padding: usize) -> bool {
 fn emit_to_destination(rendered_buffer: &Vec<Vec<StyledString>>,
                        lvl: &Level,
                        dst: &mut Destination,
-                       short_message: bool,
-                       error_codes: &mut HashSet<String>)
+                       short_message: bool)
                        -> io::Result<()> {
     use lock;
 
@@ -1441,9 +1405,6 @@ fn emit_to_destination(rendered_buffer: &Vec<Vec<StyledString>>,
         for part in line {
             dst.apply_style(lvl.clone(), part.style)?;
             write!(dst, "{}", part.text)?;
-            if !short_message && part.text.len() == 12 && part.text.starts_with("error[E") {
-                error_codes.insert(part.text[6..11].to_owned());
-            }
             dst.reset_attrs()?;
         }
         if !short_message {

src/test/ui-fulldeps/lint-plugin-forbid-attrs.stderr

@@ -21,4 +21,3 @@ LL | #[allow(test_lint)]
 
 error: aborting due to 2 previous errors
 
-If you want more information on this error, try using "rustc --explain E0453"

src/test/ui-fulldeps/proc-macro/signature.stderr

@@ -12,4 +12,3 @@ LL | | }
 
 error: aborting due to previous error
 
-If you want more information on this error, try using "rustc --explain E0308"

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

@@ -154,4 +154,3 @@ LL | fn h2<F>(_: F) where F: for<'t0> Fn(&(), Box<Fn(&())>, &'t0 (), fn(&(), &()
 
 error: aborting due to 11 previous errors
 
-If you want more information on this error, try using "rustc --explain E0631"

src/test/ui/arbitrary-self-types-not-object-safe.stderr

@@ -17,4 +17,3 @@ LL |     let x = Box::new(5usize) as Box<Foo>;
 
 error: aborting due to 2 previous errors
 
-If you want more information on this error, try using "rustc --explain E0038"

src/test/ui/asm-out-assign-imm.stderr

@@ -9,4 +9,3 @@ LL |         asm!("mov $1, $0" : "=r"(x) : "r"(5));
 
 error: aborting due to previous error
 
-If you want more information on this error, try using "rustc --explain E0384"

src/test/ui/associated-const-impl-wrong-lifetime.stderr

@@ -15,4 +15,3 @@ LL | impl<'a> Foo for &'a () {
 
 error: aborting due to previous error
 
-If you want more information on this error, try using "rustc --explain E0308"

src/test/ui/associated-const-impl-wrong-type.stderr

@@ -9,4 +9,3 @@ LL |     const BAR: i32 = -1;
 
 error: aborting due to previous error
 
-If you want more information on this error, try using "rustc --explain E0326"

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

@@ -42,5 +42,3 @@ LL | fn paint<C:BoxCar>(c: C, d: C::Color) {
 
 error: aborting due to 4 previous errors
 
-You've got a few errors: E0191, E0221
-If you want more information on an error, try using "rustc --explain E0191"

src/test/ui/associated-types-ICE-when-projecting-out-of-err.stderr

@@ -6,4 +6,3 @@ LL |     r = r + a;
 
 error: aborting due to previous error
 
-If you want more information on this error, try using "rustc --explain E0277"

src/test/ui/associated-types-in-ambiguous-context.stderr

@@ -24,4 +24,3 @@ LL |     fn grab(&self) -> Grab::Value;
 
 error: aborting due to 3 previous errors
 
-If you want more information on this error, try using "rustc --explain E0223"

src/test/ui/attr-usage-repr.stderr

@@ -40,4 +40,3 @@ LL | enum ESimd { A, B }
 
 error: aborting due to 5 previous errors
 
-If you want more information on this error, try using "rustc --explain E0517"

src/test/ui/augmented-assignments.stderr

@@ -20,5 +20,3 @@ LL |     x;  //~ value moved here
 
 error: aborting due to 2 previous errors
 
-You've got a few errors: E0382, E0596
-If you want more information on an error, try using "rustc --explain E0382"

src/test/ui/binary-op-on-double-ref.stderr

@@ -9,4 +9,3 @@ LL |         x % 2 == 0
 
 error: aborting due to previous error
 
-If you want more information on this error, try using "rustc --explain E0369"

src/test/ui/blind-item-item-shadow.stderr

@@ -15,4 +15,3 @@ LL | use foo::foo as other_foo;
 
 error: aborting due to previous error
 
-If you want more information on this error, try using "rustc --explain E0255"

src/test/ui/block-result/block-must-not-have-result-do.stderr

@@ -9,4 +9,3 @@ LL |         true //~  ERROR mismatched types
 
 error: aborting due to previous error
 
-If you want more information on this error, try using "rustc --explain E0308"

src/test/ui/block-result/block-must-not-have-result-res.stderr

@@ -11,4 +11,3 @@ LL |         true //~  ERROR mismatched types
 
 error: aborting due to previous error
 
-If you want more information on this error, try using "rustc --explain E0308"

src/test/ui/block-result/block-must-not-have-result-while.stderr

@@ -9,4 +9,3 @@ LL |         true //~  ERROR mismatched types
 
 error: aborting due to previous error
 
-If you want more information on this error, try using "rustc --explain E0308"

src/test/ui/block-result/consider-removing-last-semi.stderr

@@ -28,4 +28,3 @@ LL | | }
 
 error: aborting due to 2 previous errors
 
-If you want more information on this error, try using "rustc --explain E0308"

src/test/ui/block-result/issue-11714.stderr

@@ -15,4 +15,3 @@ LL | | }
 
 error: aborting due to previous error
 
-If you want more information on this error, try using "rustc --explain E0308"

src/test/ui/block-result/issue-13428.stderr

@@ -31,4 +31,3 @@ LL | | }
 
 error: aborting due to 2 previous errors
 
-If you want more information on this error, try using "rustc --explain E0308"

src/test/ui/block-result/issue-13624.stderr

@@ -20,4 +20,3 @@ LL |         a::Enum::EnumStructVariant { x, y, z } => {
 
 error: aborting due to 2 previous errors
 
-If you want more information on this error, try using "rustc --explain E0308"

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

@@ -17,5 +17,3 @@ LL |     let x = foo(5)(2);
 
 error: aborting due to 2 previous errors
 
-You've got a few errors: E0308, E0618
-If you want more information on an error, try using "rustc --explain E0308"

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

@@ -22,5 +22,3 @@ LL |   b + 3 //~ ERROR E0277
 
 error: aborting due to 2 previous errors
 
-You've got a few errors: E0277, E0308
-If you want more information on an error, try using "rustc --explain E0277"

src/test/ui/block-result/issue-3563.stderr

@@ -8,4 +8,3 @@ LL |         || self.b()
 
 error: aborting due to previous error
 
-If you want more information on this error, try using "rustc --explain E0599"

src/test/ui/block-result/issue-5500.stderr

@@ -11,4 +11,3 @@ LL |     &panic!()
 
 error: aborting due to previous error
 
-If you want more information on this error, try using "rustc --explain E0308"

src/test/ui/block-result/unexpected-return-on-unit.stderr

@@ -17,4 +17,3 @@ LL | fn bar() -> usize {
 
 error: aborting due to previous error
 
-If you want more information on this error, try using "rustc --explain E0308"

src/test/ui/bogus-tag.stderr

@@ -9,4 +9,3 @@ LL |       color::hsl(h, s, l) => { println!("hsl"); }
 
 error: aborting due to previous error
 
-If you want more information on this error, try using "rustc --explain E0599"

src/test/ui/borrowck/borrowck-box-insensitivity.stderr

@@ -161,5 +161,3 @@ LL | }
 
 error: aborting due to 16 previous errors
 
-You've got a few errors: E0382, E0502, E0503, E0505
-If you want more information on an error, try using "rustc --explain E0382"

src/test/ui/borrowck/borrowck-closures-two-mut.stderr

@@ -150,4 +150,3 @@ LL | }
 
 error: aborting due to 10 previous errors
 
-If you want more information on this error, try using "rustc --explain E0499"

src/test/ui/borrowck/borrowck-escaping-closure-error-1.stderr

@@ -12,4 +12,3 @@ LL |     spawn(move || books.push(4));
 
 error: aborting due to previous error
 
-If you want more information on this error, try using "rustc --explain E0373"

src/test/ui/borrowck/borrowck-escaping-closure-error-2.stderr

@@ -12,4 +12,3 @@ LL |     Box::new(move || books.push(4))
 
 error: aborting due to previous error
 
-If you want more information on this error, try using "rustc --explain E0373"

src/test/ui/borrowck/borrowck-in-static.stderr

@@ -8,4 +8,3 @@ LL |     Box::new(|| x) //~ ERROR cannot move out of captured outer variable
 
 error: aborting due to previous error
 
-If you want more information on this error, try using "rustc --explain E0507"

src/test/ui/borrowck/borrowck-move-error-with-note.stderr

@@ -34,5 +34,3 @@ LL |         n => {
 
 error: aborting due to 3 previous errors
 
-You've got a few errors: E0507, E0509
-If you want more information on an error, try using "rustc --explain E0507"

src/test/ui/borrowck/borrowck-move-out-of-vec-tail.stderr

@@ -15,4 +15,3 @@ LL | |                   Foo { string: b }] => {
 
 error: aborting due to previous error
 
-If you want more information on this error, try using "rustc --explain E0508"

src/test/ui/borrowck/borrowck-reinit.stderr

@@ -20,4 +20,3 @@ LL |     let _ = (1,x); //~ ERROR use of moved value: `x` (Ast)
 
 error: aborting due to 2 previous errors
 
-If you want more information on this error, try using "rustc --explain E0382"

src/test/ui/borrowck/borrowck-report-with-custom-diagnostic.stderr

@@ -36,5 +36,3 @@ LL |     };
 
 error: aborting due to 3 previous errors
 
-You've got a few errors: E0499, E0502
-If you want more information on an error, try using "rustc --explain E0499"

src/test/ui/borrowck/borrowck-vec-pattern-nesting.stderr

@@ -80,5 +80,3 @@ LL |     let a = vec[0]; //~ ERROR cannot move out
 
 error: aborting due to 8 previous errors
 
-You've got a few errors: E0506, E0508
-If you want more information on an error, try using "rustc --explain E0506"

src/test/ui/borrowck/immutable-arg.stderr

@@ -16,4 +16,3 @@ LL |     _x = 4;
 
 error: aborting due to 2 previous errors
 
-If you want more information on this error, try using "rustc --explain E0384"

src/test/ui/borrowck/issue-41962.stderr

@@ -54,4 +54,3 @@ LL |         if let Some(thing) = maybe {
 
 error: aborting due to 5 previous errors
 
-If you want more information on this error, try using "rustc --explain E0382"

src/test/ui/borrowck/mut-borrow-in-loop.stderr

@@ -27,4 +27,3 @@ LL |     }
 
 error: aborting due to 3 previous errors
 
-If you want more information on this error, try using "rustc --explain E0499"

src/test/ui/borrowck/mut-borrow-outside-loop.stderr

@@ -21,4 +21,3 @@ LL |     }
 
 error: aborting due to 2 previous errors
 
-If you want more information on this error, try using "rustc --explain E0499"

src/test/ui/borrowck/regions-bound-missing-bound-in-impl.stderr

@@ -46,5 +46,3 @@ LL |     fn another_bound<'x: 't>(self, x: Inv<'x>, y: Inv<'t>) {
 
 error: aborting due to 4 previous errors
 
-You've got a few errors: E0195, E0276, E0308
-If you want more information on an error, try using "rustc --explain E0195"

src/test/ui/borrowck/unboxed-closures-move-upvar-from-non-once-ref-closure.stderr

@@ -9,4 +9,3 @@ LL |         y.into_iter();
 
 error: aborting due to previous error
 
-If you want more information on this error, try using "rustc --explain E0507"

src/test/ui/cast-as-bool.stderr

@@ -8,4 +8,3 @@ LL |     let u = 5 as bool;
 
 error: aborting due to previous error
 
-If you want more information on this error, try using "rustc --explain E0054"

src/test/ui/cast-errors-issue-43825.stderr

@@ -6,4 +6,3 @@ LL |     let error = error; //~ ERROR cannot find value `error`
 
 error: aborting due to previous error
 
-If you want more information on this error, try using "rustc --explain E0425"

src/test/ui/cast-rfc0401-2.stderr

@@ -8,4 +8,3 @@ LL |     let _ = 3 as bool;
 
 error: aborting due to previous error
 
-If you want more information on this error, try using "rustc --explain E0054"

src/test/ui/cast-to-unsized-trait-object-suggestion.stderr

@@ -16,4 +16,3 @@ LL |     Box::new(1) as Send; //~ ERROR cast to unsized
 
 error: aborting due to 2 previous errors
 
-If you want more information on this error, try using "rustc --explain E0620"

src/test/ui/casts-differing-anon.stderr

@@ -8,4 +8,3 @@ LL |     b_raw = f_raw as *mut _; //~ ERROR is invalid
 
 error: aborting due to previous error
 
-If you want more information on this error, try using "rustc --explain E0606"

src/test/ui/casts-issue-46365.stderr

@@ -6,4 +6,3 @@ LL |     ipsum: Ipsum //~ ERROR cannot find type `Ipsum`
 
 error: aborting due to previous error
 
-If you want more information on this error, try using "rustc --explain E0412"

src/test/ui/changing-crates.stderr

@@ -11,4 +11,3 @@ LL | extern crate b; //~ ERROR: found possibly newer version of crate `a` which
 
 error: aborting due to previous error
 
-If you want more information on this error, try using "rustc --explain E0460"