Add symbol normalization for proc_macro_server.

Author: crlf0710

src/librustc_expand/proc_macro_server.rs

@@ -1,5 +1,6 @@
 use crate::base::ExtCtxt;
 
+use rustc_parse::lexer::nfc_normalize;
 use rustc_parse::{nt_to_tokenstream, parse_stream_from_source_str};
 use syntax::ast;
 use syntax::print::pprust;
@@ -327,6 +328,7 @@ impl Ident {
         }
     }
     fn new(sym: Symbol, is_raw: bool, span: Span) -> Ident {
+        let sym = nfc_normalize(&sym.as_str());
         let string = sym.as_str();
         if !Self::is_valid(&string) {
             panic!("`{:?}` is not a valid identifier", string)

src/librustc_parse/lexer/mod.rs

@@ -471,16 +471,9 @@ impl<'a> StringReader<'a> {
 
     /// As symbol_from, with the text normalized into Unicode NFC form.
     fn nfc_symbol_from(&self, start: BytePos) -> Symbol {
-        use unicode_normalization::{is_nfc_quick, IsNormalized, UnicodeNormalization};
         debug!("taking an normalized ident from {:?} to {:?}", start, self.pos);
         let sym = self.str_from(start);
-        match is_nfc_quick(sym.chars()) {
-            IsNormalized::Yes => Symbol::intern(sym),
-            _ => {
-                let sym_str: String = sym.chars().nfc().collect();
-                Symbol::intern(&sym_str)
-            }
-        }
+        nfc_normalize(sym)
     }
 
     /// Slice of the source text spanning from `start` up to but excluding `end`.
@@ -651,3 +644,14 @@ impl<'a> StringReader<'a> {
         }
     }
 }
+
+pub fn nfc_normalize(string: &str) -> Symbol {
+    use unicode_normalization::{is_nfc_quick, IsNormalized, UnicodeNormalization};
+    match is_nfc_quick(string.chars()) {
+        IsNormalized::Yes => Symbol::intern(string),
+        _ => {
+            let normalized_str: String = string.chars().nfc().collect();
+            Symbol::intern(&normalized_str)
+        }
+    }
+}