rust-lang · bors · Feb 28, 2021 · Feb 7, 2021 · Feb 7, 2021 · Feb 7, 2021
diff --git a/compiler/rustc_parse/src/lexer/mod.rs b/compiler/rustc_parse/src/lexer/mod.rs
@@ -268,6 +268,9 @@ impl<'a> StringReader<'a> {
                 // tokens like `<<` from `rustc_lexer`, and then add fancier error recovery to it,
                 // as there will be less overall work to do this way.
                 let token = unicode_chars::check_for_substitution(self, start, c, &mut err);
+                if c == '\x00' {
+                    err.help("source files must be encoded in UTF-8, unexpected null bytes might occur when the wrong text encoding is used");
+                }
                 err.emit();
                 token?
             }

diff --git a/src/test/ui/parser/issue-66473.stderr b/src/test/ui/parser/issue-66473.stderr
diff --git a/src/test/ui/parser/issue-68629.stderr b/src/test/ui/parser/issue-68629.stderr
diff --git a/src/test/ui/parser/issue-68730.stderr b/src/test/ui/parser/issue-68730.stderr
diff --git a/src/test/ui/parser/utf16-be-without-bom.rs b/src/test/ui/parser/utf16-be-without-bom.rs
diff --git a/src/test/ui/parser/utf16-be-without-bom.stderr b/src/test/ui/parser/utf16-be-without-bom.stderr
diff --git a/src/test/ui/parser/utf16-le-without-bom.rs b/src/test/ui/parser/utf16-le-without-bom.rs
diff --git a/src/test/ui/parser/utf16-le-without-bom.stderr b/src/test/ui/parser/utf16-le-without-bom.stderr