Avoid rustc_span:: qualifiers.

In several files they are entirely unnecessary, with the relevant names
already imported. And in a few I have added the necessary `use` item.

Author: nnethercote

compiler/rustc_attr_parsing/src/attributes/allow_unstable.rs

@@ -10,7 +10,7 @@ use crate::session_diagnostics;
 
 pub(crate) struct AllowInternalUnstableParser;
 impl CombineAttributeParser for AllowInternalUnstableParser {
-    const PATH: &'static [rustc_span::Symbol] = &[sym::allow_internal_unstable];
+    const PATH: &'static [Symbol] = &[sym::allow_internal_unstable];
     type Item = (Symbol, Span);
     const CONVERT: ConvertFn<Self::Item> = AttributeKind::AllowInternalUnstable;
 
@@ -24,7 +24,7 @@ impl CombineAttributeParser for AllowInternalUnstableParser {
 
 pub(crate) struct AllowConstFnUnstableParser;
 impl CombineAttributeParser for AllowConstFnUnstableParser {
-    const PATH: &'static [rustc_span::Symbol] = &[sym::rustc_allow_const_fn_unstable];
+    const PATH: &'static [Symbol] = &[sym::rustc_allow_const_fn_unstable];
     type Item = Symbol;
     const CONVERT: ConvertFn<Self::Item> = AttributeKind::AllowConstFnUnstable;
 

compiler/rustc_attr_parsing/src/attributes/deprecation.rs

@@ -42,9 +42,9 @@ fn get(
 }
 
 impl SingleAttributeParser for DeprecationParser {
-    const PATH: &'static [rustc_span::Symbol] = &[sym::deprecated];
+    const PATH: &'static [Symbol] = &[sym::deprecated];
 
-    fn on_duplicate(cx: &AcceptContext<'_>, first_span: rustc_span::Span) {
+    fn on_duplicate(cx: &AcceptContext<'_>, first_span: Span) {
         // FIXME(jdonszelmann): merge with errors from check_attrs.rs
         cx.emit_err(session_diagnostics::UnusedMultiple {
             this: cx.attr_span,

compiler/rustc_attr_parsing/src/attributes/mod.rs

@@ -17,7 +17,7 @@
 use std::marker::PhantomData;
 
 use rustc_attr_data_structures::AttributeKind;
-use rustc_span::Span;
+use rustc_span::{Span, Symbol};
 use thin_vec::ThinVec;
 
 use crate::context::{AcceptContext, FinalizeContext};
@@ -33,7 +33,7 @@ pub(crate) mod transparency;
 pub(crate) mod util;
 
 type AcceptFn<T> = fn(&mut T, &AcceptContext<'_>, &ArgParser<'_>);
-type AcceptMapping<T> = &'static [(&'static [rustc_span::Symbol], AcceptFn<T>)];
+type AcceptMapping<T> = &'static [(&'static [Symbol], AcceptFn<T>)];
 
 /// An [`AttributeParser`] is a type which searches for syntactic attributes.
 ///
@@ -72,7 +72,7 @@ pub(crate) trait AttributeParser: Default + 'static {
 /// [`SingleAttributeParser`] can only convert attributes one-to-one, and cannot combine multiple
 /// attributes together like is necessary for `#[stable()]` and `#[unstable()]` for example.
 pub(crate) trait SingleAttributeParser: 'static {
-    const PATH: &'static [rustc_span::Symbol];
+    const PATH: &'static [Symbol];
 
     /// Caled when a duplicate attribute is found.
     ///
@@ -119,7 +119,7 @@ type ConvertFn<E> = fn(ThinVec<E>) -> AttributeKind;
 /// [`CombineAttributeParser`] can only convert a single kind of attribute, and cannot combine multiple
 /// attributes together like is necessary for `#[stable()]` and `#[unstable()]` for example.
 pub(crate) trait CombineAttributeParser: 'static {
-    const PATH: &'static [rustc_span::Symbol];
+    const PATH: &'static [Symbol];
 
     type Item;
     const CONVERT: ConvertFn<Self::Item>;

compiler/rustc_attr_parsing/src/attributes/repr.rs

@@ -1,7 +1,7 @@
 use rustc_abi::Align;
 use rustc_ast::{IntTy, LitIntType, LitKind, UintTy};
 use rustc_attr_data_structures::{AttributeKind, IntType, ReprAttr};
-use rustc_span::{Span, Symbol, sym};
+use rustc_span::{DUMMY_SP, Span, Symbol, sym};
 
 use super::{CombineAttributeParser, ConvertFn};
 use crate::context::AcceptContext;
@@ -21,7 +21,7 @@ pub(crate) struct ReprParser;
 
 impl CombineAttributeParser for ReprParser {
     type Item = (ReprAttr, Span);
-    const PATH: &'static [rustc_span::Symbol] = &[sym::repr];
+    const PATH: &'static [Symbol] = &[sym::repr];
     const CONVERT: ConvertFn<Self::Item> = AttributeKind::Repr;
 
     fn extend<'a>(
@@ -99,7 +99,7 @@ fn parse_repr(cx: &AcceptContext<'_>, param: &MetaItemParser<'_>) -> Option<Repr
     let (name, ident_span) = if let Some(ident) = param.path_without_args().word() {
         (Some(ident.name), ident.span)
     } else {
-        (None, rustc_span::DUMMY_SP)
+        (None, DUMMY_SP)
     };
 
     let args = param.args();

compiler/rustc_attr_parsing/src/attributes/stability.rs

@@ -117,7 +117,7 @@ impl AttributeParser for BodyStabilityParser {
 pub(crate) struct ConstStabilityIndirectParser;
 // FIXME(jdonszelmann): single word attribute group when we have these
 impl SingleAttributeParser for ConstStabilityIndirectParser {
-    const PATH: &'static [rustc_span::Symbol] = &[sym::rustc_const_stable_indirect];
+    const PATH: &'static [Symbol] = &[sym::rustc_const_stable_indirect];
 
     // ignore
     fn on_duplicate(_cx: &AcceptContext<'_>, _first_span: Span) {}

compiler/rustc_attr_parsing/src/attributes/transparency.rs

@@ -1,6 +1,6 @@
 use rustc_attr_data_structures::AttributeKind;
 use rustc_span::hygiene::Transparency;
-use rustc_span::sym;
+use rustc_span::{Span, Symbol, sym};
 
 use super::{AcceptContext, SingleAttributeParser};
 use crate::parser::ArgParser;
@@ -11,9 +11,9 @@ pub(crate) struct TransparencyParser;
 #[allow(rustc::untranslatable_diagnostic)]
 #[allow(rustc::diagnostic_outside_of_impl)]
 impl SingleAttributeParser for TransparencyParser {
-    const PATH: &'static [rustc_span::Symbol] = &[sym::rustc_macro_transparency];
+    const PATH: &'static [Symbol] = &[sym::rustc_macro_transparency];
 
-    fn on_duplicate(cx: &crate::context::AcceptContext<'_>, first_span: rustc_span::Span) {
+    fn on_duplicate(cx: &crate::context::AcceptContext<'_>, first_span: Span) {
         cx.dcx().span_err(vec![first_span, cx.attr_span], "multiple macro transparency attributes");
     }
 

compiler/rustc_attr_parsing/src/parser.rs

@@ -12,8 +12,7 @@ use rustc_ast::{AttrArgs, DelimArgs, Expr, ExprKind, LitKind, MetaItemLit, Norma
 use rustc_ast_pretty::pprust;
 use rustc_errors::DiagCtxtHandle;
 use rustc_hir::{self as hir, AttrPath};
-use rustc_span::symbol::{Ident, kw, sym};
-use rustc_span::{ErrorGuaranteed, Span, Symbol};
+use rustc_span::{ErrorGuaranteed, Ident, Span, Symbol, kw, sym};
 
 pub struct SegmentIterator<'a> {
     offset: usize,