Add ES6 extended (braced) unicode literals.

This adds support for the form \u{xxxxxx}

js/src/frontend/TokenStream.cpp

@@ -1656,6 +1656,37 @@ TokenStream::getTokenInternal(TokenKind* ttp, Modifier modifier)
     return false;
 }
 
+bool
+TokenStream::getBracedUnicode(uint32_t* cp)
+{
+    consumeKnownChar('{');
+
+    bool first = true;
+    int32_t c;
+    uint32_t code = 0;
+    while (true) {
+        c = getCharIgnoreEOL();
+        if (c == EOF)
+            return false;
+        if (c == '}') {
+            if (first)
+                return false;
+            break;
+        }
+
+        if (!JS7_ISHEX(c))
+            return false;
+
+        code = (code << 4) | JS7_UNHEX(c);
+        if (code > 0x10FFFF)
+            return false;
+        first = false;
+    }
+
+    *cp = code;
+    return true;
+}
+
 bool
 TokenStream::getStringOrTemplateToken(int untilChar, Token** tp)
 {
@@ -1693,6 +1724,24 @@ TokenStream::getStringOrTemplateToken(int untilChar, Token** tp)
 
               // Unicode character specification.
               case 'u': {
+                if (peekChar() == '{') {
+                    uint32_t code;
+                    if (!getBracedUnicode(&code)) {
+                        reportError(JSMSG_MALFORMED_ESCAPE, "Unicode");
+                        return false;
+                    }
+
+                    MOZ_ASSERT(code <= 0x10FFFF);
+                    if (code < 0x10000) {
+                        c = code;
+                    } else {
+                        if (!tokenbuf.append((code - 0x10000) / 1024 + 0xD800))
+                            return false;
+                        c = ((code - 0x10000) % 1024) + 0xDC00;
+                    }
+                    break;
+                }
+
                 char16_t cp[4];
                 if (peekChars(4, cp) &&
                     JS7_ISHEX(cp[0]) && JS7_ISHEX(cp[1]) && JS7_ISHEX(cp[2]) && JS7_ISHEX(cp[3]))

js/src/frontend/TokenStream.h

@@ -771,6 +771,7 @@ class MOZ_STACK_CLASS TokenStream
 
     bool getTokenInternal(TokenKind* ttp, Modifier modifier);
 
+    bool getBracedUnicode(uint32_t* code);
     bool getStringOrTemplateToken(int untilChar, Token** tp);
 
     int32_t getChar();

js/src/tests/ecma_6/String/unicode-braced.js

@@ -0,0 +1,64 @@
+var BUGNUMBER = 320500;
+var summary = 'Add \\u{xxxxxx} string literals';
+
+print(BUGNUMBER + ": " + summary);
+
+assertEq("\u{0}", String.fromCodePoint(0x0));
+assertEq("\u{1}", String.fromCodePoint(0x1));
+assertEq("\u{10}", String.fromCodePoint(0x10));
+assertEq("\u{100}", String.fromCodePoint(0x100));
+assertEq("\u{1000}", String.fromCodePoint(0x1000));
+assertEq("\u{D7FF}", String.fromCodePoint(0xD7FF));
+assertEq("\u{D800}", String.fromCodePoint(0xD800));
+assertEq("\u{DBFF}", String.fromCodePoint(0xDBFF));
+assertEq("\u{DC00}", String.fromCodePoint(0xDC00));
+assertEq("\u{DFFF}", String.fromCodePoint(0xDFFF));
+assertEq("\u{E000}", String.fromCodePoint(0xE000));
+assertEq("\u{10000}", String.fromCodePoint(0x10000));
+assertEq("\u{100000}", String.fromCodePoint(0x100000));
+assertEq("\u{10FFFF}", String.fromCodePoint(0x10FFFF));
+assertEq("\u{10ffff}", String.fromCodePoint(0x10FFFF));
+
+assertEq("A\u{1}\u{10}B\u{100}\u{1000}\u{10000}C\u{100000}",
+         "A" +
+         String.fromCodePoint(0x1) +
+         String.fromCodePoint(0x10) +
+         "B" +
+         String.fromCodePoint(0x100) +
+         String.fromCodePoint(0x1000) +
+         String.fromCodePoint(0x10000) +
+         "C" +
+         String.fromCodePoint(0x100000));
+
+assertEq('\u{10ffff}', String.fromCodePoint(0x10FFFF));
+assertEq(`\u{10ffff}`, String.fromCodePoint(0x10FFFF));
+assertEq(`\u{10ffff}${""}`, String.fromCodePoint(0x10FFFF));
+assertEq(`${""}\u{10ffff}`, String.fromCodePoint(0x10FFFF));
+assertEq(`${""}\u{10ffff}${""}`, String.fromCodePoint(0x10FFFF));
+
+assertEq("\u{00}", String.fromCodePoint(0x0));
+assertEq("\u{00000000000000000}", String.fromCodePoint(0x0));
+assertEq("\u{00000000000001000}", String.fromCodePoint(0x1000));
+
+assertEq(eval(`"\\u{${"0".repeat(Math.pow(2, 24)) + "1234"}}"`), String.fromCodePoint(0x1234));
+
+assertEq("\U{0}", "U{0}");
+
+assertThrowsInstanceOf(() => eval(`"\\u{-1}"`), SyntaxError);
+assertThrowsInstanceOf(() => eval(`"\\u{0.0}"`), SyntaxError);
+assertThrowsInstanceOf(() => eval(`"\\u{G}"`), SyntaxError);
+assertThrowsInstanceOf(() => eval(`"\\u{}"`), SyntaxError);
+assertThrowsInstanceOf(() => eval(`"\\u{{"`), SyntaxError);
+assertThrowsInstanceOf(() => eval(`"\\u{"`), SyntaxError);
+assertThrowsInstanceOf(() => eval(`"\\u{110000}"`), SyntaxError);
+assertThrowsInstanceOf(() => eval(`"\\u{00110000}"`), SyntaxError);
+assertThrowsInstanceOf(() => eval(`"\\u{100000000000000000000000000000}"`), SyntaxError);
+assertThrowsInstanceOf(() => eval(`"\\u{FFFFFFFFFFFFFFFFFFFFFFFFFFFFFF}"`), SyntaxError);
+assertThrowsInstanceOf(() => eval(`"\\u{   FFFF}"`), SyntaxError);
+assertThrowsInstanceOf(() => eval(`"\\u{FFFF   }"`), SyntaxError);
+assertThrowsInstanceOf(() => eval(`"\\u{FF   FF}"`), SyntaxError);
+assertThrowsInstanceOf(() => eval(`"\\u{F F F F}"`), SyntaxError);
+assertThrowsInstanceOf(() => eval(`"\\u{100000001}"`), SyntaxError);
+
+if (typeof reportCompare === "function")
+  reportCompare(true, true);