Rollup merge of #103749 - est31:reduce_irrefutable_let_else_span, r=cjgillot

[rust.git] / compiler / rustc_span / src / lib.rs

diff --git a/compiler/rustc_span/src/lib.rs b/compiler/rustc_span/src/lib.rs
index f8df4169715939695359c8d72c2c01dd23b2520e..322c7104be425966930a74ff37dfb7d0219b14b5 100644 (file)
--- a/compiler/rustc_span/src/lib.rs
+++ b/compiler/rustc_span/src/lib.rs
@@ -298,7 +298,11 @@ fn from(p: PathBuf) -> Self {
 
 #[derive(Clone, Copy, Eq, PartialEq, Hash, Debug)]
 pub enum FileNameDisplayPreference {
+    /// Display the path after the application of rewrite rules provided via `--remap-path-prefix`.
+    /// This is appropriate for paths that get embedded into files produced by the compiler.
     Remapped,
+    /// Display the path before the application of rewrite rules provided via `--remap-path-prefix`.
+    /// This is appropriate for use in user-facing output (such as diagnostics).
     Local,
 }
 
@@ -554,7 +558,7 @@ pub fn is_dummy(self) -> bool {
         self.data_untracked().is_dummy()
     }
 
-    /// Returns `true` if this span comes from a macro or desugaring.
+    /// Returns `true` if this span comes from any kind of macro, desugaring or inlining.
     #[inline]
     pub fn from_expansion(self) -> bool {
         self.ctxt() != SyntaxContext::root()
@@ -567,6 +571,12 @@ pub fn in_macro_expansion_with_collapse_debuginfo(self) -> bool {
         matches!(outer_expn.kind, ExpnKind::Macro(..)) && outer_expn.collapse_debuginfo
     }
 
+    /// Returns `true` if this span comes from MIR inlining.
+    pub fn is_inlined(self) -> bool {
+        let outer_expn = self.ctxt().outer_expn_data();
+        matches!(outer_expn.kind, ExpnKind::Inlined)
+    }
+
     /// Returns `true` if `span` originates in a derive-macro's expansion.
     pub fn in_derive_expansion(self) -> bool {
         matches!(self.ctxt().outer_expn_data().kind, ExpnKind::Macro(MacroKind::Derive, _))
@@ -1627,10 +1637,7 @@ pub fn count_lines(&self) -> usize {
     /// number. If the source_file is empty or the position is located before the
     /// first line, `None` is returned.
     pub fn lookup_line(&self, pos: BytePos) -> Option<usize> {
-        self.lines(|lines| match lines.partition_point(|x| x <= &pos) {
-            0 => None,
-            i => Some(i - 1),
-        })
+        self.lines(|lines| lines.partition_point(|x| x <= &pos).checked_sub(1))
     }
 
     pub fn line_bounds(&self, line_index: usize) -> Range<BytePos> {