Use the same message as type & const generics.

compiler/rustc_error_codes/src/error_codes/E0263.md

@@ -1,8 +1,10 @@
+#### Note: this error code is no longer emitted by the compiler.
+
 A lifetime was declared more than once in the same scope.
 
 Erroneous code example:
 
-```compile_fail,E0263
+```compile_fail,E0403
 fn foo<'a, 'b, 'a>(x: &'a str, y: &'b str, z: &'a str) { // error!
 }
 ```

compiler/rustc_resolve/src/late.rs

@@ -1885,9 +1885,8 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
  let mut function_value_rib = Rib::new(kind);
  let mut function_lifetime_rib = LifetimeRib::new(lifetime_kind);
  let mut seen_bindings = FxHashMap::default();
- // Store all seen lifetimes names, and whether they were created in the currently processed
- // parameter set.
- let mut seen_lifetimes = FxHashMap::default();
+ // Store all seen lifetimes names from outer scopes.
+ let mut seen_lifetimes = FxHashSet::default();
 
  // We also can't shadow bindings from the parent item
  if let AssocItemRibKind = kind {
@@ -1905,7 +1904,7 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
 
  // Forbid shadowing lifetime bindings
  for rib in self.lifetime_ribs.iter().rev() {
- seen_lifetimes.extend(rib.bindings.iter().map(|(ident, _)| (*ident, false)));
+ seen_lifetimes.extend(rib.bindings.iter().map(|(ident, _)| *ident));
  if let LifetimeRibKind::Item = rib.kind {
  break;
  }
@@ -1915,35 +1914,28 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
  let ident = param.ident.normalize_to_macros_2_0();
  debug!("with_generic_param_rib: {}", param.id);
 
- if let GenericParamKind::Lifetime = param.kind {
- match seen_lifetimes.entry(ident) {
- Entry::Occupied(entry) => {
- let original = *entry.key();
- let orig_is_param = *entry.get();
- diagnostics::signal_lifetime_shadowing(
- self.r.session,
- original,
- param.ident,
- orig_is_param,
- );
+ if let GenericParamKind::Lifetime = param.kind
+ && let Some(&original) = seen_lifetimes.get(&ident)
+ {
+ diagnostics::signal_lifetime_shadowing(self.r.session, original, param.ident);
+ // Record lifetime res, so lowering knows there is something fishy.
+ self.record_lifetime_res(param.id, LifetimeRes::Error);
+ continue;
+ }
+
+ match seen_bindings.entry(ident) {
+ Entry::Occupied(entry) => {
+ let span = *entry.get();
+ let err = ResolutionError::NameAlreadyUsedInParameterList(ident.name, span);
+ self.report_error(param.ident.span, err);
+ if let GenericParamKind::Lifetime = param.kind {
  // Record lifetime res, so lowering knows there is something fishy.
  self.record_lifetime_res(param.id, LifetimeRes::Error);
  continue;
  }
- Entry::Vacant(entry) => {
- entry.insert(true);
- }
  }
- } else {
- match seen_bindings.entry(ident) {
- Entry::Occupied(entry) => {
- let span = *entry.get();
- let err = ResolutionError::NameAlreadyUsedInParameterList(ident.name, span);
- self.report_error(param.ident.span, err);
- }
- Entry::Vacant(entry) => {
- entry.insert(param.ident.span);
- }
+ Entry::Vacant(entry) => {
+ entry.insert(param.ident.span);
  }
  }
 

compiler/rustc_resolve/src/late/diagnostics.rs

@@ -2038,29 +2038,14 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
 }
 
 /// Report lifetime/lifetime shadowing as an error.
-pub fn signal_lifetime_shadowing(
- sess: &Session,
- orig: Ident,
- shadower: Ident,
- orig_is_param: bool,
-) {
- let mut err = if orig_is_param {
- struct_span_err!(
- sess,
- shadower.span,
- E0263,
- "lifetime name `{}` declared twice in the same scope",
- orig.name,
- )
- } else {
- struct_span_err!(
- sess,
- shadower.span,
- E0496,
- "lifetime name `{}` shadows a lifetime name that is already in scope",
- orig.name,
- )
- };
+pub fn signal_lifetime_shadowing(sess: &Session, orig: Ident, shadower: Ident) {
+ let mut err = struct_span_err!(
+ sess,
+ shadower.span,
+ E0496,
+ "lifetime name `{}` shadows a lifetime name that is already in scope",
+ orig.name,
+ );
  err.span_label(orig.span, "first declared here");
  err.span_label(shadower.span, format!("lifetime `{}` already in scope", orig.name));
  err.emit();

src/test/ui/error-codes/E0263.rs

@@ -1,5 +1,5 @@
 fn foo<'a, 'b, 'a>(x: &'a str, y: &'b str) {
- //~^ ERROR E0263
+ //~^ ERROR E0403
 }
 
 fn main() {}

src/test/ui/error-codes/E0263.stderr

@@ -1,11 +1,11 @@
-error[E0263]: lifetime name `'a` declared twice in the same scope
+error[E0403]: the name `'a` is already used for a generic parameter in this item's generic parameters
  --> $DIR/E0263.rs:1:16
  |
 LL | fn foo<'a, 'b, 'a>(x: &'a str, y: &'b str) {
- | -- ^^ lifetime `'a` already in scope
+ | -- ^^ already used
  | |
- | first declared here
+ | first use of `'a`
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0263`.
+For more information about this error, try `rustc --explain E0403`.

src/test/ui/hygiene/duplicate_lifetimes.rs

@@ -5,12 +5,12 @@
 
 #[rustc_macro_transparency = "semitransparent"]
 macro m($a:lifetime) {
- fn g<$a, 'a>() {} //~ ERROR lifetime name `'a` declared twice
+ fn g<$a, 'a>() {} //~ ERROR the name `'a` is already used for a generic parameter
 }
 
 #[rustc_macro_transparency = "transparent"]
 macro n($a:lifetime) {
- fn h<$a, 'a>() {} //~ ERROR lifetime name `'a` declared twice
+ fn h<$a, 'a>() {} //~ ERROR the name `'a` is already used for a generic parameter
 }
 
 m!('a);

src/test/ui/hygiene/duplicate_lifetimes.stderr

@@ -1,31 +1,31 @@
-error[E0263]: lifetime name `'a` declared twice in the same scope
+error[E0403]: the name `'a` is already used for a generic parameter in this item's generic parameters
  --> $DIR/duplicate_lifetimes.rs:8:14
  |
 LL | fn g<$a, 'a>() {}
- | ^^ lifetime `'a` already in scope
+ | ^^ already used
 ...
 LL | m!('a);
  | ------
  | | |
- | | first declared here
+ | | first use of `'a`
  | in this macro invocation
  |
  = note: this error originates in the macro `m` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error[E0263]: lifetime name `'a` declared twice in the same scope
+error[E0403]: the name `'a` is already used for a generic parameter in this item's generic parameters
  --> $DIR/duplicate_lifetimes.rs:13:14
  |
 LL | fn h<$a, 'a>() {}
- | ^^ lifetime `'a` already in scope
+ | ^^ already used
 ...
 LL | n!('a);
  | ------
  | | |
- | | first declared here
+ | | first use of `'a`
  | in this macro invocation
  |
  = note: this error originates in the macro `n` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: aborting due to 2 previous errors
 
-For more information about this error, try `rustc --explain E0263`.
+For more information about this error, try `rustc --explain E0403`.

src/test/ui/regions/regions-name-duplicated.rs

@@ -1,5 +1,5 @@
 struct Foo<'a, 'a> {
- //~^ ERROR lifetime name `'a` declared twice
+ //~^ ERROR the name `'a` is already used for a generic parameter
  x: &'a isize,
 }
 

src/test/ui/regions/regions-name-duplicated.stderr

@@ -1,11 +1,11 @@
-error[E0263]: lifetime name `'a` declared twice in the same scope
+error[E0403]: the name `'a` is already used for a generic parameter in this item's generic parameters
  --> $DIR/regions-name-duplicated.rs:1:16
  |
 LL | struct Foo<'a, 'a> {
- | -- ^^ lifetime `'a` already in scope
+ | -- ^^ already used
  | |
- | first declared here
+ | first use of `'a`
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0263`.
+For more information about this error, try `rustc --explain E0403`.