static bool
EvalStringMightBeJSON(const mozilla::Range<const CharT> chars)
{
// If the eval string starts with '(' or '[' and ends with ')' or ']', it may be JSON.
// Try the JSON parser first because it's much faster. If the eval string
// isn't JSON, JSON parsing will probably fail quickly, so little time
// will be lost.
size_t length = chars.length();
if (length > 2 &&
((chars[0] == '[' && chars[length - 1] == ']') ||
(chars[0] == '(' && chars[length - 1] == ')')))
{
// Remarkably, JavaScript syntax is not a superset of JSON syntax:
// strings in JavaScript cannot contain the Unicode line and paragraph
// terminator characters U+2028 and U+2029, but strings in JSON can.
// Rather than force the JSON parser to handle this quirk when used by
// eval, we simply don't use the JSON parser when either character
// appears in the provided string. See bug 657367.
if (sizeof(CharT) > 1) {
for (RangedPtr<const CharT> cp = chars.start() + 1, end = chars.end() - 1;
cp < end;
cp++)
{
char16_t c = *cp;
if (c == 0x2028 || c == 0x2029)
return false;
}
}
return true;
}
return false;
}
static bool
ArgsAndBodySubstring(mozilla::Range<const CharT> chars, size_t *outOffset, size_t *outLen)
{
const CharT *const start = chars.start().get();
const CharT *const end = chars.end().get();
const CharT *s = start;
uint8_t parenChomp = 0;
if (s[0] == '(') {
s++;
parenChomp = 1;
}
/* Try to jump "function" keyword. */
s = js_strchr_limit(s, ' ', end);
if (!s)
return false;
/*
* Jump over the function's name: it can't be encoded as part
* of an ECMA getter or setter.
*/
s = js_strchr_limit(s, '(', end);
if (!s)
return false;
if (*s == ' ')
s++;
*outOffset = s - start;
*outLen = end - s - parenChomp;
MOZ_ASSERT(*outOffset + *outLen <= chars.length());
return true;
}