Re-add updated Span::start()/end()/line()/column() span-locations methods

Updated for rust-lang/rust#111571

Author: MingweiSamuel

.gitignore

@@ -1,3 +1,4 @@
 /target
 **/*.rs.bk
 Cargo.lock
+/.vscode

Cargo.toml

@@ -31,7 +31,7 @@ rustversion = "1"
 proc-macro = []
 default = ["proc-macro"]
 
-# Expose methods Span::start and Span::end which give the line/column location
+# Expose the old Span::start and Span::end methods which give the line/column location
 # of a token.
 span-locations = []
 

src/fallback.rs

@@ -1,5 +1,3 @@
-#[cfg(span_locations)]
-use crate::location::LineColumn;
 use crate::parse::{self, Cursor};
 use crate::rcvec::{RcVec, RcVecBuilder, RcVecIntoIter, RcVecMut};
 use crate::{Delimiter, Spacing, TokenTree};
@@ -357,21 +355,16 @@ struct FileInfo {
 
 #[cfg(all(span_locations, not(fuzzing)))]
 impl FileInfo {
-    fn offset_line_column(&self, offset: usize) -> LineColumn {
+    /// Returns `(line, column)`.
+    fn offset_line_column(&self, offset: usize) -> (usize, usize) {
         assert!(self.span_within(Span {
             lo: offset as u32,
             hi: offset as u32
         }));
         let offset = offset - self.span.lo as usize;
         match self.lines.binary_search(&offset) {
-            Ok(found) => LineColumn {
-                line: found + 1,
-                column: 0,
-            },
-            Err(idx) => LineColumn {
-                line: idx,
-                column: offset - self.lines[idx - 1],
-            },
+            Ok(found) => (found + 1, 0),
+            Err(idx) => (idx, offset - self.lines[idx - 1]),
         }
     }
 
@@ -516,9 +509,26 @@ impl Span {
     }
 
     #[cfg(span_locations)]
-    pub fn start(&self) -> LineColumn {
+    pub fn start(&self) -> Self {
+        Self {
+            lo: self.lo,
+            hi: self.lo,
+        }
+    }
+
+    #[cfg(span_locations)]
+    pub fn end(&self) -> Self {
+        Self {
+            lo: self.hi,
+            hi: self.hi,
+        }
+    }
+
+    /// Helper: returns `(line, column)`.
+    #[cfg(span_locations)]
+    fn line_column(&self) -> (usize, usize) {
         #[cfg(fuzzing)]
-        return LineColumn { line: 0, column: 0 };
+        return (0, 0);
 
         #[cfg(not(fuzzing))]
         SOURCE_MAP.with(|cm| {
@@ -529,16 +539,13 @@ impl Span {
     }
 
     #[cfg(span_locations)]
-    pub fn end(&self) -> LineColumn {
-        #[cfg(fuzzing)]
-        return LineColumn { line: 0, column: 0 };
+    pub fn line(&self) -> usize {
+        self.line_column().0
+    }
 
-        #[cfg(not(fuzzing))]
-        SOURCE_MAP.with(|cm| {
-            let cm = cm.borrow();
-            let fi = cm.fileinfo(*self);
-            fi.offset_line_column(self.hi as usize)
-        })
+    #[cfg(span_locations)]
+    pub fn column(&self) -> usize {
+        self.line_column().1
     }
 
     #[cfg(not(span_locations))]

src/lib.rs

@@ -142,8 +142,6 @@ mod imp;
 
 #[cfg(span_locations)]
 mod convert;
-#[cfg(span_locations)]
-mod location;
 
 use crate::extra::DelimSpan;
 use crate::marker::Marker;
@@ -157,9 +155,6 @@ use std::error::Error;
 #[cfg(procmacro2_semver_exempt)]
 use std::path::PathBuf;
 
-#[cfg(span_locations)]
-pub use crate::location::LineColumn;
-
 /// An abstract stream of tokens, or more concretely a sequence of token trees.
 ///
 /// This type provides interfaces for iterating over token trees and for
@@ -461,7 +456,27 @@ impl Span {
         SourceFile::_new(self.inner.source_file())
     }
 
-    /// Get the starting line/column in the source file for this span.
+    /// Creates an empty span pointing to directly before this span.
+    ///
+    /// This method requires the `"span-locations"` feature to be enabled.
+    #[cfg(span_locations)]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "span-locations")))]
+    pub fn start(&self) -> Self {
+        Self::_new(self.inner.start())
+    }
+
+    /// Creates an empty span pointing to directly after this span.
+    ///
+    /// This method requires the `"span-locations"` feature to be enabled.
+    #[cfg(span_locations)]
+    #[cfg_attr(doc_cfg, doc(cfg(feature = "span-locations")))]
+    pub fn end(&self) -> Self {
+        Self::_new(self.inner.end())
+    }
+
+    /// The one-indexed line of the source file where the span starts.
+    ///
+    /// To obtain the line of the span's end, use `span.end().line()`.
     ///
     /// This method requires the `"span-locations"` feature to be enabled.
     ///
@@ -472,11 +487,13 @@ impl Span {
     /// line/column are always meaningful regardless of toolchain.
     #[cfg(span_locations)]
     #[cfg_attr(doc_cfg, doc(cfg(feature = "span-locations")))]
-    pub fn start(&self) -> LineColumn {
-        self.inner.start()
+    pub fn line(&self) -> usize {
+        self.inner.line()
     }
 
-    /// Get the ending line/column in the source file for this span.
+    /// The one-indexed column of the source file where the span starts.
+    ///
+    /// To obtain the column of the span's end, use `span.end().column()`.
     ///
     /// This method requires the `"span-locations"` feature to be enabled.
     ///
@@ -487,8 +504,8 @@ impl Span {
     /// line/column are always meaningful regardless of toolchain.
     #[cfg(span_locations)]
     #[cfg_attr(doc_cfg, doc(cfg(feature = "span-locations")))]
-    pub fn end(&self) -> LineColumn {
-        self.inner.end()
+    pub fn column(&self) -> usize {
+        self.inner.column()
     }
 
     /// Create a new span encompassing `self` and `other`.

src/location.rs

@@ -1,6 +1,4 @@
 use crate::detection::inside_proc_macro;
-#[cfg(span_locations)]
-use crate::location::LineColumn;
 use crate::{fallback, Delimiter, Punct, Spacing, TokenTree};
 use core::fmt::{self, Debug, Display};
 use core::iter::FromIterator;
@@ -468,22 +466,38 @@ impl Span {
     }
 
     #[cfg(span_locations)]
-    pub fn start(&self) -> LineColumn {
+    pub fn start(&self) -> Self {
         match self {
-            Span::Compiler(_) => LineColumn { line: 0, column: 0 },
-            Span::Fallback(s) => s.start(),
+            Self::Compiler(s) => Self::Compiler(s.start()),
+            Self::Fallback(s) => Self::Fallback(s.start()),
         }
     }
 
     #[cfg(span_locations)]
-    pub fn end(&self) -> LineColumn {
+    pub fn end(&self) -> Self {
         match self {
-            Span::Compiler(_) => LineColumn { line: 0, column: 0 },
-            Span::Fallback(s) => s.end(),
+            Self::Compiler(s) => Self::Compiler(s.end()),
+            Self::Fallback(s) => Self::Fallback(s.end()),
         }
     }
 
-    pub fn join(&self, other: Span) -> Option<Span> {
+    #[cfg(span_locations)]
+    pub fn line(&self) -> usize {
+        match self {
+            Self::Compiler(s) => s.line(),
+            Self::Fallback(s) => s.line(),
+        }
+    }
+
+    #[cfg(span_locations)]
+    pub fn column(&self) -> usize {
+        match self {
+            Self::Compiler(s) => s.column(),
+            Self::Fallback(s) => s.column(),
+        }
+    }
+
+    pub fn join(&self, other: Self) -> Option<Span> {
         let ret = match (self, other) {
             #[cfg(proc_macro_span)]
             (Span::Compiler(a), Span::Compiler(b)) => Span::Compiler(a.join(b)?),

src/wrapper.rs

@@ -55,9 +55,7 @@ assert_impl!(TokenTree is not Send or Sync);
 
 #[cfg(procmacro2_semver_exempt)]
 mod semver_exempt {
-    use proc_macro2::{LineColumn, SourceFile};
-
-    assert_impl!(LineColumn is Send and Sync);
+    use proc_macro2::SourceFile;
 
     assert_impl!(SourceFile is not Send or Sync);
 }
@@ -68,7 +66,7 @@ mod unwind_safe {
         Delimiter, Group, Ident, LexError, Literal, Punct, Spacing, Span, TokenStream, TokenTree,
     };
     #[cfg(procmacro2_semver_exempt)]
-    use proc_macro2::{LineColumn, SourceFile};
+    use proc_macro2::SourceFile;
     use std::panic::{RefUnwindSafe, UnwindSafe};
 
     macro_rules! assert_unwind_safe {
@@ -94,7 +92,6 @@ mod unwind_safe {
 
     #[cfg(procmacro2_semver_exempt)]
     assert_unwind_safe! {
-        LineColumn
         SourceFile
     }
 }

tests/marker.rs

@@ -331,10 +331,10 @@ fn literal_span() {
 
     #[cfg(span_locations)]
     {
-        assert_eq!(positive.span().start().column, 0);
-        assert_eq!(positive.span().end().column, 3);
-        assert_eq!(negative.span().start().column, 0);
-        assert_eq!(negative.span().end().column, 4);
+        assert_eq!(positive.span().start().column(), 0);
+        assert_eq!(positive.span().end().column(), 3);
+        assert_eq!(negative.span().start().column(), 0);
+        assert_eq!(negative.span().end().column(), 4);
         assert_eq!(subspan.unwrap().source_text().unwrap(), ".");
     }
 
@@ -432,11 +432,11 @@ testing 123
 #[test]
 fn default_span() {
     let start = Span::call_site().start();
-    assert_eq!(start.line, 1);
-    assert_eq!(start.column, 0);
+    assert_eq!(start.line(), 1);
+    assert_eq!(start.column(), 0);
     let end = Span::call_site().end();
-    assert_eq!(end.line, 1);
-    assert_eq!(end.column, 0);
+    assert_eq!(end.line(), 1);
+    assert_eq!(end.column(), 0);
     let source_file = Span::call_site().source_file();
     assert_eq!(source_file.path().to_string_lossy(), "<unspecified>");
     assert!(!source_file.is_real());
@@ -469,10 +469,10 @@ fn span_join() {
 
     let start = joined1.unwrap().start();
     let end = joined1.unwrap().end();
-    assert_eq!(start.line, 1);
-    assert_eq!(start.column, 0);
-    assert_eq!(end.line, 2);
-    assert_eq!(end.column, 3);
+    assert_eq!(start.line(), 1);
+    assert_eq!(start.column(), 0);
+    assert_eq!(end.line(), 2);
+    assert_eq!(end.column(), 3);
 
     assert_eq!(
         joined1.unwrap().source_file(),
@@ -717,12 +717,12 @@ fn check_spans_internal(ts: TokenStream, lines: &mut &[(usize, usize, usize, usi
             *lines = rest;
 
             let start = i.span().start();
-            assert_eq!(start.line, sline, "sline did not match for {}", i);
-            assert_eq!(start.column, scol, "scol did not match for {}", i);
+            assert_eq!(start.line(), sline, "sline did not match for {}", i);
+            assert_eq!(start.column(), scol, "scol did not match for {}", i);
 
             let end = i.span().end();
-            assert_eq!(end.line, eline, "eline did not match for {}", i);
-            assert_eq!(end.column, ecol, "ecol did not match for {}", i);
+            assert_eq!(end.line(), eline, "eline did not match for {}", i);
+            assert_eq!(end.column(), ecol, "ecol did not match for {}", i);
 
             if let TokenTree::Group(g) = i {
                 check_spans_internal(g.stream().clone(), lines);