Auto merge of #68633 - JohnTitor:avoid-ice-in-diagnostics, r=estebank

[rust.git] / src / librustc_errors / lib.rs

diff --git a/src/librustc_errors/lib.rs b/src/librustc_errors/lib.rs
index e24e8719133a987574b2d9def7200801d42a9b93..17b293401f89ef1e60813c7f1fff74dc457f93e0 100644 (file)
--- a/src/librustc_errors/lib.rs
+++ b/src/librustc_errors/lib.rs
@@ -10,6 +10,7 @@
 
 pub use emitter::ColorConfig;
 
+use log::debug;
 use Level::*;
 
 use emitter::{is_case_difference, Emitter, EmitterWriter};
@@ -174,17 +175,27 @@ fn push_trailing(
 
         self.substitutions
             .iter()
+            .filter(|subst| {
+                // Suggestions coming from macros can have malformed spans. This is a heavy
+                // handed approach to avoid ICEs by ignoring the suggestion outright.
+                let invalid = subst.parts.iter().any(|item| cm.is_valid_span(item.span).is_err());
+                if invalid {
+                    debug!("splice_lines: suggestion contains an invalid span: {:?}", subst);
+                }
+                !invalid
+            })
             .cloned()
-            .map(|mut substitution| {
+            .filter_map(|mut substitution| {
                 // Assumption: all spans are in the same file, and all spans
                 // are disjoint. Sort in ascending order.
                 substitution.parts.sort_by_key(|part| part.span.lo());
 
                 // Find the bounding span.
-                let lo = substitution.parts.iter().map(|part| part.span.lo()).min().unwrap();
-                let hi = substitution.parts.iter().map(|part| part.span.hi()).max().unwrap();
+                let lo = substitution.parts.iter().map(|part| part.span.lo()).min()?;
+                let hi = substitution.parts.iter().map(|part| part.span.hi()).max()?;
                 let bounding_span = Span::with_root_ctxt(lo, hi);
-                let lines = cm.span_to_lines(bounding_span).unwrap();
+                // The different spans might belong to different contexts, if so ignore suggestion.
+                let lines = cm.span_to_lines(bounding_span).ok()?;
                 assert!(!lines.lines.is_empty());
 
                 // To build up the result, we do this for each span:
@@ -234,7 +245,7 @@ fn push_trailing(
                 while buf.ends_with('\n') {
                     buf.pop();
                 }
-                (buf, substitution.parts, only_capitalization)
+                Some((buf, substitution.parts, only_capitalization))
             })
             .collect()
     }