Parse Unicode string escape \u{XX...}.

Thanks to drbo.

1 files changed, 27 insertions, 0 deletions

diff --git a/src/lj_lex.c b/src/lj_lex.c
index 8409cd78..5a918f74 100644
--- a/src/lj_lex.c
+++ b/src/lj_lex.c
@@ -214,6 +214,33 @@ static void lex_string(LexState *ls, TValue *tv)
           c += 9;
         }
         break;
+      case 'u':  /* Unicode escape '\u{XX...}'. */
+        if (lex_next(ls) != '{') goto err_xesc;
+        lex_next(ls);
+        c = 0;
+        do {
+          c = (c << 4) | (ls->c & 15u);
+          if (!lj_char_isdigit(ls->c)) {
+            if (!lj_char_isxdigit(ls->c)) goto err_xesc;
+            c += 9;
+          }
+          if (c >= 0x110000) goto err_xesc;  /* Out of Unicode range. */
+        } while (lex_next(ls) != '}');
+        if (c < 0x800) {
+          if (c < 0x80) break;
+          lex_save(ls, 0xc0 | (c >> 6));
+        } else {
+          if (c >= 0x10000) {
+            lex_save(ls, 0xf0 | (c >> 18));
+            lex_save(ls, 0x80 | ((c >> 12) & 0x3f));
+          } else {
+            if (c >= 0xd800 && c < 0xe000) goto err_xesc;  /* No surrogates. */
+            lex_save(ls, 0xe0 | (c >> 12));
+          }
+          lex_save(ls, 0x80 | ((c >> 6) & 0x3f));
+        }
+        c = 0x80 | (c & 0x3f);
+        break;
       case 'z':  /* Skip whitespace. */
         lex_next(ls);
         while (lj_char_isspace(ls->c))