Rollup merge of #111571 - jhpratt:proc-macro-span, r=m-ou-se

Implement proposed API for `proc_macro_span`

As proposed in [#54725 (comment)](https://github.com/rust-lang/rust/issues/54725#issuecomment-1546918161). I have omitted the byte-level API as it's already available as [`Span::byte_range`](https://doc.rust-lang.org/nightly/proc_macro/struct.Span.html#method.byte_range).

`@rustbot` label +A-proc-macros

r? `@m-ou-se`

1 files changed, 11 insertions, 12 deletions

diff --git a/compiler/rustc_expand/src/proc_macro_server.rs b/compiler/rustc_expand/src/proc_macro_server.rs
index 891e84a2f30..ecd2315112a 100644
--- a/compiler/rustc_expand/src/proc_macro_server.rs
+++ b/compiler/rustc_expand/src/proc_macro_server.rs
@@ -2,7 +2,7 @@ use crate::base::ExtCtxt;
 use pm::bridge::{
     server, DelimSpan, Diagnostic, ExpnGlobals, Group, Ident, LitKind, Literal, Punct, TokenTree,
 };
-use pm::{Delimiter, Level, LineColumn};
+use pm::{Delimiter, Level};
 use rustc_ast as ast;
 use rustc_ast::token;
 use rustc_ast::tokenstream::{self, Spacing::*, TokenStream};
@@ -648,23 +648,22 @@ impl server::Span for Rustc<'_, '_> {
 
         Range { start: relative_start_pos.0 as usize, end: relative_end_pos.0 as usize }
     }
-
-    fn start(&mut self, span: Self::Span) -> LineColumn {
-        let loc = self.sess().source_map().lookup_char_pos(span.lo());
-        LineColumn { line: loc.line, column: loc.col.to_usize() }
+    fn start(&mut self, span: Self::Span) -> Self::Span {
+        span.shrink_to_lo()
     }
 
-    fn end(&mut self, span: Self::Span) -> LineColumn {
-        let loc = self.sess().source_map().lookup_char_pos(span.hi());
-        LineColumn { line: loc.line, column: loc.col.to_usize() }
+    fn end(&mut self, span: Self::Span) -> Self::Span {
+        span.shrink_to_hi()
     }
 
-    fn before(&mut self, span: Self::Span) -> Self::Span {
-        span.shrink_to_lo()
+    fn line(&mut self, span: Self::Span) -> usize {
+        let loc = self.sess().source_map().lookup_char_pos(span.lo());
+        loc.line
     }
 
-    fn after(&mut self, span: Self::Span) -> Self::Span {
-        span.shrink_to_hi()
+    fn column(&mut self, span: Self::Span) -> usize {
+        let loc = self.sess().source_map().lookup_char_pos(span.lo());
+        loc.col.to_usize() + 1
     }
 
     fn join(&mut self, first: Self::Span, second: Self::Span) -> Option<Self::Span> {