1832     StringRef UsedPrefix;  in readCheckFile()  local
1834     std::tie(UsedPrefix, AfterSuffix) =  in readCheckFile()
1836     if (UsedPrefix.empty())  in readCheckFile()
1839       PrefixesNotFound.erase(UsedPrefix);  in readCheckFile()
1841     assert(UsedPrefix.data() == Buffer.data() &&  in readCheckFile()
1849     const char *UsedPrefixStart = UsedPrefix.data();  in readCheckFile()
1853     Buffer = AfterSuffix.empty() ? Buffer.drop_front(UsedPrefix.size())  in readCheckFile()
1858       StringRef UsedDirective(UsedPrefix.data(),  in readCheckFile()
1859                               AfterSuffix.data() - UsedPrefix.data());  in readCheckFile()
1869                       "unsupported -NOT combo on prefix '" + UsedPrefix + "'");  in readCheckFile()
1877                           UsedPrefix + "'");  in readCheckFile()
1902     if (P.parsePattern(PatternBuffer, UsedPrefix, SM, Req))  in readCheckFile()
1909           "found '" + UsedPrefix + "-LABEL:'"  in readCheckFile()
1923                       "found '" + UsedPrefix + "-" + Type +  in readCheckFile()
1924                           "' without previous '" + UsedPrefix + ": line");  in readCheckFile()
1930       DagNotMatches.emplace_back(P, UsedPrefix);  in readCheckFile()
1935     CheckStrings->emplace_back(P, UsedPrefix, PatternLoc);  in readCheckFile()