058455ffbe
FileCheck string substitution block parsing code only report an invalid variable name in a string variable use if it starts with a forbidden character. It does not report anything if there are unparsed characters after the variable name, i.e. [[X-Y]] is parsed as [[X]] and no error is returned. This commit fixes that. Reviewed By: jdenny, jhenderson Differential Revision: https://reviews.llvm.org/D98691