+static cl::list<std::string>
+CheckPrefixes("check-prefix",
+ cl::desc("Prefix to use from check file (defaults to 'CHECK')"));
+
+static cl::opt<bool>
+NoCanonicalizeWhiteSpace("strict-whitespace",
+ cl::desc("Do not treat all horizontal whitespace as equivalent"));
+
+static cl::list<std::string> ImplicitCheckNot(
+ "implicit-check-not",
+ cl::desc("Add an implicit negative check with this pattern to every\n"
+ "positive check. This can be used to ensure that no instances of\n"
+ "this pattern occur which are not matched by a positive pattern"),
+ cl::value_desc("pattern"));
+
+static cl::opt<bool> AllowEmptyInput(
+ "allow-empty", cl::init(false),
+ cl::desc("Allow the input file to be empty. This is useful when making\n"
+ "checks that some error message does not occur, for example."));
+
+typedef cl::list<std::string>::const_iterator prefix_iterator;
+
+//===----------------------------------------------------------------------===//
+// Pattern Handling Code.
+//===----------------------------------------------------------------------===//
+
+namespace Check {
+ enum CheckType {
+ CheckNone = 0,
+ CheckPlain,
+ CheckNext,
+ CheckNot,
+ CheckDAG,
+ CheckLabel,
+
+ /// MatchEOF - When set, this pattern only matches the end of file. This is
+ /// used for trailing CHECK-NOTs.
+ CheckEOF
+ };
+}
+
+class Pattern {
+ SMLoc PatternLoc;
+
+ Check::CheckType CheckTy;
+
+ /// FixedStr - If non-empty, this pattern is a fixed string match with the
+ /// specified fixed string.
+ StringRef FixedStr;
+
+ /// RegEx - If non-empty, this is a regex pattern.
+ std::string RegExStr;
+
+ /// \brief Contains the number of line this pattern is in.
+ unsigned LineNumber;
+
+ /// VariableUses - Entries in this vector map to uses of a variable in the
+ /// pattern, e.g. "foo[[bar]]baz". In this case, the RegExStr will contain
+ /// "foobaz" and we'll get an entry in this vector that tells us to insert the
+ /// value of bar at offset 3.
+ std::vector<std::pair<StringRef, unsigned> > VariableUses;
+
+ /// VariableDefs - Maps definitions of variables to their parenthesized
+ /// capture numbers.
+ /// E.g. for the pattern "foo[[bar:.*]]baz", VariableDefs will map "bar" to 1.
+ std::map<StringRef, unsigned> VariableDefs;
+
+public:
+
+ Pattern(Check::CheckType Ty)
+ : CheckTy(Ty) { }
+
+ /// getLoc - Return the location in source code.
+ SMLoc getLoc() const { return PatternLoc; }
+
+ /// ParsePattern - Parse the given string into the Pattern. Prefix provides
+ /// which prefix is being matched, SM provides the SourceMgr used for error
+ /// reports, and LineNumber is the line number in the input file from which
+ /// the pattern string was read. Returns true in case of an error, false
+ /// otherwise.
+ bool ParsePattern(StringRef PatternStr,
+ StringRef Prefix,
+ SourceMgr &SM,
+ unsigned LineNumber);
+
+ /// Match - Match the pattern string against the input buffer Buffer. This
+ /// returns the position that is matched or npos if there is no match. If
+ /// there is a match, the size of the matched string is returned in MatchLen.
+ ///
+ /// The VariableTable StringMap provides the current values of filecheck
+ /// variables and is updated if this match defines new values.
+ size_t Match(StringRef Buffer, size_t &MatchLen,
+ StringMap<StringRef> &VariableTable) const;
+
+ /// PrintFailureInfo - Print additional information about a failure to match
+ /// involving this pattern.
+ void PrintFailureInfo(const SourceMgr &SM, StringRef Buffer,
+ const StringMap<StringRef> &VariableTable) const;
+
+ bool hasVariable() const { return !(VariableUses.empty() &&
+ VariableDefs.empty()); }
+
+ Check::CheckType getCheckTy() const { return CheckTy; }
+
+private:
+ bool AddRegExToRegEx(StringRef RS, unsigned &CurParen, SourceMgr &SM);
+ void AddBackrefToRegEx(unsigned BackrefNum);
+
+ /// ComputeMatchDistance - Compute an arbitrary estimate for the quality of
+ /// matching this pattern at the start of \arg Buffer; a distance of zero
+ /// should correspond to a perfect match.
+ unsigned ComputeMatchDistance(StringRef Buffer,
+ const StringMap<StringRef> &VariableTable) const;
+
+ /// \brief Evaluates expression and stores the result to \p Value.
+ /// \return true on success. false when the expression has invalid syntax.
+ bool EvaluateExpression(StringRef Expr, std::string &Value) const;
+
+ /// \brief Finds the closing sequence of a regex variable usage or
+ /// definition. Str has to point in the beginning of the definition
+ /// (right after the opening sequence).
+ /// \return offset of the closing sequence within Str, or npos if it was not
+ /// found.
+ size_t FindRegexVarEnd(StringRef Str, SourceMgr &SM);
+};
+
+
+bool Pattern::ParsePattern(StringRef PatternStr,
+ StringRef Prefix,
+ SourceMgr &SM,
+ unsigned LineNumber) {
+ this->LineNumber = LineNumber;
+ PatternLoc = SMLoc::getFromPointer(PatternStr.data());
+
+ // Ignore trailing whitespace.
+ while (!PatternStr.empty() &&
+ (PatternStr.back() == ' ' || PatternStr.back() == '\t'))
+ PatternStr = PatternStr.substr(0, PatternStr.size()-1);
+
+ // Check that there is something on the line.
+ if (PatternStr.empty()) {
+ SM.PrintMessage(PatternLoc, SourceMgr::DK_Error,
+ "found empty check string with prefix '" +
+ Prefix + ":'");
+ return true;
+ }
+
+ // Check to see if this is a fixed string, or if it has regex pieces.
+ if (PatternStr.size() < 2 ||
+ (PatternStr.find("{{") == StringRef::npos &&
+ PatternStr.find("[[") == StringRef::npos)) {
+ FixedStr = PatternStr;
+ return false;
+ }
+
+ // Paren value #0 is for the fully matched string. Any new parenthesized
+ // values add from there.
+ unsigned CurParen = 1;
+
+ // Otherwise, there is at least one regex piece. Build up the regex pattern
+ // by escaping scary characters in fixed strings, building up one big regex.
+ while (!PatternStr.empty()) {
+ // RegEx matches.
+ if (PatternStr.startswith("{{")) {
+ // This is the start of a regex match. Scan for the }}.
+ size_t End = PatternStr.find("}}");
+ if (End == StringRef::npos) {
+ SM.PrintMessage(SMLoc::getFromPointer(PatternStr.data()),
+ SourceMgr::DK_Error,
+ "found start of regex string with no end '}}'");
+ return true;
+ }
+
+ // Enclose {{}} patterns in parens just like [[]] even though we're not
+ // capturing the result for any purpose. This is required in case the
+ // expression contains an alternation like: CHECK: abc{{x|z}}def. We
+ // want this to turn into: "abc(x|z)def" not "abcx|zdef".
+ RegExStr += '(';
+ ++CurParen;
+
+ if (AddRegExToRegEx(PatternStr.substr(2, End-2), CurParen, SM))
+ return true;
+ RegExStr += ')';
+
+ PatternStr = PatternStr.substr(End+2);
+ continue;
+ }
+
+ // Named RegEx matches. These are of two forms: [[foo:.*]] which matches .*
+ // (or some other regex) and assigns it to the FileCheck variable 'foo'. The
+ // second form is [[foo]] which is a reference to foo. The variable name
+ // itself must be of the form "[a-zA-Z_][0-9a-zA-Z_]*", otherwise we reject
+ // it. This is to catch some common errors.
+ if (PatternStr.startswith("[[")) {
+ // Find the closing bracket pair ending the match. End is going to be an
+ // offset relative to the beginning of the match string.
+ size_t End = FindRegexVarEnd(PatternStr.substr(2), SM);
+
+ if (End == StringRef::npos) {
+ SM.PrintMessage(SMLoc::getFromPointer(PatternStr.data()),
+ SourceMgr::DK_Error,
+ "invalid named regex reference, no ]] found");
+ return true;
+ }
+
+ StringRef MatchStr = PatternStr.substr(2, End);
+ PatternStr = PatternStr.substr(End+4);
+
+ // Get the regex name (e.g. "foo").
+ size_t NameEnd = MatchStr.find(':');
+ StringRef Name = MatchStr.substr(0, NameEnd);
+
+ if (Name.empty()) {
+ SM.PrintMessage(SMLoc::getFromPointer(Name.data()), SourceMgr::DK_Error,
+ "invalid name in named regex: empty name");
+ return true;
+ }
+
+ // Verify that the name/expression is well formed. FileCheck currently
+ // supports @LINE, @LINE+number, @LINE-number expressions. The check here
+ // is relaxed, more strict check is performed in \c EvaluateExpression.
+ bool IsExpression = false;
+ for (unsigned i = 0, e = Name.size(); i != e; ++i) {
+ if (i == 0 && Name[i] == '@') {
+ if (NameEnd != StringRef::npos) {
+ SM.PrintMessage(SMLoc::getFromPointer(Name.data()),
+ SourceMgr::DK_Error,
+ "invalid name in named regex definition");
+ return true;
+ }
+ IsExpression = true;
+ continue;
+ }
+ if (Name[i] != '_' && !isalnum(Name[i]) &&
+ (!IsExpression || (Name[i] != '+' && Name[i] != '-'))) {
+ SM.PrintMessage(SMLoc::getFromPointer(Name.data()+i),
+ SourceMgr::DK_Error, "invalid name in named regex");
+ return true;
+ }
+ }
+
+ // Name can't start with a digit.
+ if (isdigit(static_cast<unsigned char>(Name[0]))) {
+ SM.PrintMessage(SMLoc::getFromPointer(Name.data()), SourceMgr::DK_Error,
+ "invalid name in named regex");
+ return true;
+ }
+
+ // Handle [[foo]].
+ if (NameEnd == StringRef::npos) {
+ // Handle variables that were defined earlier on the same line by
+ // emitting a backreference.
+ if (VariableDefs.find(Name) != VariableDefs.end()) {
+ unsigned VarParenNum = VariableDefs[Name];
+ if (VarParenNum < 1 || VarParenNum > 9) {
+ SM.PrintMessage(SMLoc::getFromPointer(Name.data()),
+ SourceMgr::DK_Error,
+ "Can't back-reference more than 9 variables");
+ return true;
+ }
+ AddBackrefToRegEx(VarParenNum);
+ } else {
+ VariableUses.push_back(std::make_pair(Name, RegExStr.size()));
+ }
+ continue;
+ }
+
+ // Handle [[foo:.*]].
+ VariableDefs[Name] = CurParen;
+ RegExStr += '(';
+ ++CurParen;
+
+ if (AddRegExToRegEx(MatchStr.substr(NameEnd+1), CurParen, SM))
+ return true;
+
+ RegExStr += ')';
+ }
+
+ // Handle fixed string matches.
+ // Find the end, which is the start of the next regex.
+ size_t FixedMatchEnd = PatternStr.find("{{");
+ FixedMatchEnd = std::min(FixedMatchEnd, PatternStr.find("[["));
+ RegExStr += Regex::escape(PatternStr.substr(0, FixedMatchEnd));
+ PatternStr = PatternStr.substr(FixedMatchEnd);
+ }
+
+ return false;
+}
+
+bool Pattern::AddRegExToRegEx(StringRef RS, unsigned &CurParen,
+ SourceMgr &SM) {
+ Regex R(RS);
+ std::string Error;
+ if (!R.isValid(Error)) {
+ SM.PrintMessage(SMLoc::getFromPointer(RS.data()), SourceMgr::DK_Error,
+ "invalid regex: " + Error);
+ return true;
+ }
+
+ RegExStr += RS.str();
+ CurParen += R.getNumMatches();
+ return false;
+}
+
+void Pattern::AddBackrefToRegEx(unsigned BackrefNum) {
+ assert(BackrefNum >= 1 && BackrefNum <= 9 && "Invalid backref number");
+ std::string Backref = std::string("\\") +
+ std::string(1, '0' + BackrefNum);
+ RegExStr += Backref;
+}
+
+bool Pattern::EvaluateExpression(StringRef Expr, std::string &Value) const {
+ // The only supported expression is @LINE([\+-]\d+)?
+ if (!Expr.startswith("@LINE"))
+ return false;
+ Expr = Expr.substr(StringRef("@LINE").size());
+ int Offset = 0;
+ if (!Expr.empty()) {
+ if (Expr[0] == '+')
+ Expr = Expr.substr(1);
+ else if (Expr[0] != '-')
+ return false;
+ if (Expr.getAsInteger(10, Offset))
+ return false;
+ }
+ Value = llvm::itostr(LineNumber + Offset);
+ return true;
+}
+
+/// Match - Match the pattern string against the input buffer Buffer. This
+/// returns the position that is matched or npos if there is no match. If
+/// there is a match, the size of the matched string is returned in MatchLen.
+size_t Pattern::Match(StringRef Buffer, size_t &MatchLen,
+ StringMap<StringRef> &VariableTable) const {
+ // If this is the EOF pattern, match it immediately.
+ if (CheckTy == Check::CheckEOF) {
+ MatchLen = 0;
+ return Buffer.size();
+ }
+
+ // If this is a fixed string pattern, just match it now.
+ if (!FixedStr.empty()) {
+ MatchLen = FixedStr.size();
+ return Buffer.find(FixedStr);
+ }
+
+ // Regex match.
+
+ // If there are variable uses, we need to create a temporary string with the
+ // actual value.
+ StringRef RegExToMatch = RegExStr;
+ std::string TmpStr;
+ if (!VariableUses.empty()) {
+ TmpStr = RegExStr;
+
+ unsigned InsertOffset = 0;
+ for (unsigned i = 0, e = VariableUses.size(); i != e; ++i) {
+ std::string Value;
+
+ if (VariableUses[i].first[0] == '@') {
+ if (!EvaluateExpression(VariableUses[i].first, Value))
+ return StringRef::npos;
+ } else {
+ StringMap<StringRef>::iterator it =
+ VariableTable.find(VariableUses[i].first);
+ // If the variable is undefined, return an error.
+ if (it == VariableTable.end())
+ return StringRef::npos;
+
+ // Look up the value and escape it so that we can put it into the regex.
+ Value += Regex::escape(it->second);
+ }
+
+ // Plop it into the regex at the adjusted offset.
+ TmpStr.insert(TmpStr.begin()+VariableUses[i].second+InsertOffset,
+ Value.begin(), Value.end());
+ InsertOffset += Value.size();
+ }
+
+ // Match the newly constructed regex.
+ RegExToMatch = TmpStr;
+ }
+
+
+ SmallVector<StringRef, 4> MatchInfo;
+ if (!Regex(RegExToMatch, Regex::Newline).match(Buffer, &MatchInfo))
+ return StringRef::npos;
+
+ // Successful regex match.
+ assert(!MatchInfo.empty() && "Didn't get any match");
+ StringRef FullMatch = MatchInfo[0];
+
+ // If this defines any variables, remember their values.
+ for (std::map<StringRef, unsigned>::const_iterator I = VariableDefs.begin(),
+ E = VariableDefs.end();
+ I != E; ++I) {
+ assert(I->second < MatchInfo.size() && "Internal paren error");
+ VariableTable[I->first] = MatchInfo[I->second];
+ }
+
+ MatchLen = FullMatch.size();
+ return FullMatch.data()-Buffer.data();
+}
+
+unsigned Pattern::ComputeMatchDistance(StringRef Buffer,
+ const StringMap<StringRef> &VariableTable) const {
+ // Just compute the number of matching characters. For regular expressions, we
+ // just compare against the regex itself and hope for the best.
+ //
+ // FIXME: One easy improvement here is have the regex lib generate a single
+ // example regular expression which matches, and use that as the example
+ // string.
+ StringRef ExampleString(FixedStr);
+ if (ExampleString.empty())
+ ExampleString = RegExStr;
+
+ // Only compare up to the first line in the buffer, or the string size.
+ StringRef BufferPrefix = Buffer.substr(0, ExampleString.size());
+ BufferPrefix = BufferPrefix.split('\n').first;
+ return BufferPrefix.edit_distance(ExampleString);
+}
+
+void Pattern::PrintFailureInfo(const SourceMgr &SM, StringRef Buffer,
+ const StringMap<StringRef> &VariableTable) const{
+ // If this was a regular expression using variables, print the current
+ // variable values.
+ if (!VariableUses.empty()) {
+ for (unsigned i = 0, e = VariableUses.size(); i != e; ++i) {
+ SmallString<256> Msg;
+ raw_svector_ostream OS(Msg);
+ StringRef Var = VariableUses[i].first;
+ if (Var[0] == '@') {
+ std::string Value;
+ if (EvaluateExpression(Var, Value)) {
+ OS << "with expression \"";
+ OS.write_escaped(Var) << "\" equal to \"";
+ OS.write_escaped(Value) << "\"";
+ } else {
+ OS << "uses incorrect expression \"";
+ OS.write_escaped(Var) << "\"";
+ }
+ } else {
+ StringMap<StringRef>::const_iterator it = VariableTable.find(Var);
+
+ // Check for undefined variable references.
+ if (it == VariableTable.end()) {
+ OS << "uses undefined variable \"";
+ OS.write_escaped(Var) << "\"";
+ } else {
+ OS << "with variable \"";
+ OS.write_escaped(Var) << "\" equal to \"";
+ OS.write_escaped(it->second) << "\"";
+ }
+ }
+
+ SM.PrintMessage(SMLoc::getFromPointer(Buffer.data()), SourceMgr::DK_Note,
+ OS.str());
+ }
+ }
+
+ // Attempt to find the closest/best fuzzy match. Usually an error happens
+ // because some string in the output didn't exactly match. In these cases, we
+ // would like to show the user a best guess at what "should have" matched, to
+ // save them having to actually check the input manually.
+ size_t NumLinesForward = 0;
+ size_t Best = StringRef::npos;
+ double BestQuality = 0;
+
+ // Use an arbitrary 4k limit on how far we will search.
+ for (size_t i = 0, e = std::min(size_t(4096), Buffer.size()); i != e; ++i) {
+ if (Buffer[i] == '\n')
+ ++NumLinesForward;
+
+ // Patterns have leading whitespace stripped, so skip whitespace when
+ // looking for something which looks like a pattern.
+ if (Buffer[i] == ' ' || Buffer[i] == '\t')
+ continue;
+
+ // Compute the "quality" of this match as an arbitrary combination of the
+ // match distance and the number of lines skipped to get to this match.
+ unsigned Distance = ComputeMatchDistance(Buffer.substr(i), VariableTable);
+ double Quality = Distance + (NumLinesForward / 100.);
+
+ if (Quality < BestQuality || Best == StringRef::npos) {
+ Best = i;
+ BestQuality = Quality;
+ }
+ }
+
+ // Print the "possible intended match here" line if we found something
+ // reasonable and not equal to what we showed in the "scanning from here"
+ // line.
+ if (Best && Best != StringRef::npos && BestQuality < 50) {
+ SM.PrintMessage(SMLoc::getFromPointer(Buffer.data() + Best),
+ SourceMgr::DK_Note, "possible intended match here");
+
+ // FIXME: If we wanted to be really friendly we would show why the match
+ // failed, as it can be hard to spot simple one character differences.
+ }
+}
+
+size_t Pattern::FindRegexVarEnd(StringRef Str, SourceMgr &SM) {
+ // Offset keeps track of the current offset within the input Str
+ size_t Offset = 0;
+ // [...] Nesting depth
+ size_t BracketDepth = 0;
+
+ while (!Str.empty()) {
+ if (Str.startswith("]]") && BracketDepth == 0)
+ return Offset;
+ if (Str[0] == '\\') {
+ // Backslash escapes the next char within regexes, so skip them both.
+ Str = Str.substr(2);
+ Offset += 2;
+ } else {
+ switch (Str[0]) {
+ default:
+ break;
+ case '[':
+ BracketDepth++;
+ break;
+ case ']':
+ if (BracketDepth == 0) {
+ SM.PrintMessage(SMLoc::getFromPointer(Str.data()),
+ SourceMgr::DK_Error,
+ "missing closing \"]\" for regex variable");
+ exit(1);
+ }
+ BracketDepth--;
+ break;
+ }
+ Str = Str.substr(1);
+ Offset++;
+ }
+ }
+
+ return StringRef::npos;
+}
+
+
+//===----------------------------------------------------------------------===//
+// Check Strings.
+//===----------------------------------------------------------------------===//
+
+/// CheckString - This is a check that we found in the input file.
+struct CheckString {
+ /// Pat - The pattern to match.
+ Pattern Pat;
+
+ /// Prefix - Which prefix name this check matched.
+ StringRef Prefix;
+
+ /// Loc - The location in the match file that the check string was specified.
+ SMLoc Loc;
+
+ /// CheckTy - Specify what kind of check this is. e.g. CHECK-NEXT: directive,
+ /// as opposed to a CHECK: directive.
+ Check::CheckType CheckTy;
+
+ /// DagNotStrings - These are all of the strings that are disallowed from
+ /// occurring between this match string and the previous one (or start of
+ /// file).
+ std::vector<Pattern> DagNotStrings;
+
+
+ CheckString(const Pattern &P,
+ StringRef S,
+ SMLoc L,
+ Check::CheckType Ty)
+ : Pat(P), Prefix(S), Loc(L), CheckTy(Ty) {}
+
+ /// Check - Match check string and its "not strings" and/or "dag strings".
+ size_t Check(const SourceMgr &SM, StringRef Buffer, bool IsLabelScanMode,
+ size_t &MatchLen, StringMap<StringRef> &VariableTable) const;
+
+ /// CheckNext - Verify there is a single line in the given buffer.
+ bool CheckNext(const SourceMgr &SM, StringRef Buffer) const;
+
+ /// CheckNot - Verify there's no "not strings" in the given buffer.
+ bool CheckNot(const SourceMgr &SM, StringRef Buffer,
+ const std::vector<const Pattern *> &NotStrings,
+ StringMap<StringRef> &VariableTable) const;
+
+ /// CheckDag - Match "dag strings" and their mixed "not strings".
+ size_t CheckDag(const SourceMgr &SM, StringRef Buffer,
+ std::vector<const Pattern *> &NotStrings,
+ StringMap<StringRef> &VariableTable) const;
+};
+
+/// Canonicalize whitespaces in the input file. Line endings are replaced
+/// with UNIX-style '\n'.
+///
+/// \param PreserveHorizontal Don't squash consecutive horizontal whitespace
+/// characters to a single space.
+static std::unique_ptr<MemoryBuffer>
+CanonicalizeInputFile(std::unique_ptr<MemoryBuffer> MB,
+ bool PreserveHorizontal) {
+ SmallString<128> NewFile;
+ NewFile.reserve(MB->getBufferSize());
+
+ for (const char *Ptr = MB->getBufferStart(), *End = MB->getBufferEnd();
+ Ptr != End; ++Ptr) {
+ // Eliminate trailing dosish \r.
+ if (Ptr <= End - 2 && Ptr[0] == '\r' && Ptr[1] == '\n') {
+ continue;
+ }
+
+ // If current char is not a horizontal whitespace or if horizontal
+ // whitespace canonicalization is disabled, dump it to output as is.
+ if (PreserveHorizontal || (*Ptr != ' ' && *Ptr != '\t')) {
+ NewFile.push_back(*Ptr);
+ continue;
+ }
+
+ // Otherwise, add one space and advance over neighboring space.
+ NewFile.push_back(' ');
+ while (Ptr+1 != End &&
+ (Ptr[1] == ' ' || Ptr[1] == '\t'))
+ ++Ptr;
+ }
+
+ return std::unique_ptr<MemoryBuffer>(
+ MemoryBuffer::getMemBufferCopy(NewFile.str(), MB->getBufferIdentifier()));
+}
+
+static bool IsPartOfWord(char c) {
+ return (isalnum(c) || c == '-' || c == '_');
+}
+
+// Get the size of the prefix extension.
+static size_t CheckTypeSize(Check::CheckType Ty) {
+ switch (Ty) {
+ case Check::CheckNone:
+ return 0;
+
+ case Check::CheckPlain:
+ return sizeof(":") - 1;
+
+ case Check::CheckNext:
+ return sizeof("-NEXT:") - 1;
+
+ case Check::CheckNot:
+ return sizeof("-NOT:") - 1;
+
+ case Check::CheckDAG:
+ return sizeof("-DAG:") - 1;
+
+ case Check::CheckLabel:
+ return sizeof("-LABEL:") - 1;
+
+ case Check::CheckEOF:
+ llvm_unreachable("Should not be using EOF size");
+ }
+
+ llvm_unreachable("Bad check type");
+}
+
+static Check::CheckType FindCheckType(StringRef Buffer, StringRef Prefix) {
+ char NextChar = Buffer[Prefix.size()];
+
+ // Verify that the : is present after the prefix.
+ if (NextChar == ':')
+ return Check::CheckPlain;
+
+ if (NextChar != '-')
+ return Check::CheckNone;
+
+ StringRef Rest = Buffer.drop_front(Prefix.size() + 1);
+ if (Rest.startswith("NEXT:"))
+ return Check::CheckNext;
+
+ if (Rest.startswith("NOT:"))
+ return Check::CheckNot;
+
+ if (Rest.startswith("DAG:"))
+ return Check::CheckDAG;
+
+ if (Rest.startswith("LABEL:"))
+ return Check::CheckLabel;
+
+ return Check::CheckNone;
+}
+
+// From the given position, find the next character after the word.
+static size_t SkipWord(StringRef Str, size_t Loc) {
+ while (Loc < Str.size() && IsPartOfWord(Str[Loc]))
+ ++Loc;
+ return Loc;
+}
+
+// Try to find the first match in buffer for any prefix. If a valid match is
+// found, return that prefix and set its type and location. If there are almost
+// matches (e.g. the actual prefix string is found, but is not an actual check
+// string), but no valid match, return an empty string and set the position to
+// resume searching from. If no partial matches are found, return an empty
+// string and the location will be StringRef::npos. If one prefix is a substring
+// of another, the maximal match should be found. e.g. if "A" and "AA" are
+// prefixes then AA-CHECK: should match the second one.
+static StringRef FindFirstCandidateMatch(StringRef &Buffer,
+ Check::CheckType &CheckTy,
+ size_t &CheckLoc) {
+ StringRef FirstPrefix;
+ size_t FirstLoc = StringRef::npos;
+ size_t SearchLoc = StringRef::npos;
+ Check::CheckType FirstTy = Check::CheckNone;
+
+ CheckTy = Check::CheckNone;
+ CheckLoc = StringRef::npos;
+
+ for (prefix_iterator I = CheckPrefixes.begin(), E = CheckPrefixes.end();
+ I != E; ++I) {
+ StringRef Prefix(*I);
+ size_t PrefixLoc = Buffer.find(Prefix);
+
+ if (PrefixLoc == StringRef::npos)
+ continue;
+
+ // Track where we are searching for invalid prefixes that look almost right.
+ // We need to only advance to the first partial match on the next attempt
+ // since a partial match could be a substring of a later, valid prefix.
+ // Need to skip to the end of the word, otherwise we could end up
+ // matching a prefix in a substring later.
+ if (PrefixLoc < SearchLoc)
+ SearchLoc = SkipWord(Buffer, PrefixLoc);
+
+ // We only want to find the first match to avoid skipping some.
+ if (PrefixLoc > FirstLoc)
+ continue;
+ // If one matching check-prefix is a prefix of another, choose the
+ // longer one.
+ if (PrefixLoc == FirstLoc && Prefix.size() < FirstPrefix.size())
+ continue;
+
+ StringRef Rest = Buffer.drop_front(PrefixLoc);
+ // Make sure we have actually found the prefix, and not a word containing
+ // it. This should also prevent matching the wrong prefix when one is a
+ // substring of another.
+ if (PrefixLoc != 0 && IsPartOfWord(Buffer[PrefixLoc - 1]))
+ FirstTy = Check::CheckNone;
+ else
+ FirstTy = FindCheckType(Rest, Prefix);
+
+ FirstLoc = PrefixLoc;
+ FirstPrefix = Prefix;
+ }
+
+ // If the first prefix is invalid, we should continue the search after it.
+ if (FirstTy == Check::CheckNone) {
+ CheckLoc = SearchLoc;
+ return "";
+ }
+
+ CheckTy = FirstTy;
+ CheckLoc = FirstLoc;
+ return FirstPrefix;
+}
+
+static StringRef FindFirstMatchingPrefix(StringRef &Buffer,
+ unsigned &LineNumber,
+ Check::CheckType &CheckTy,
+ size_t &CheckLoc) {
+ while (!Buffer.empty()) {
+ StringRef Prefix = FindFirstCandidateMatch(Buffer, CheckTy, CheckLoc);
+ // If we found a real match, we are done.
+ if (!Prefix.empty()) {
+ LineNumber += Buffer.substr(0, CheckLoc).count('\n');
+ return Prefix;
+ }
+
+ // We didn't find any almost matches either, we are also done.
+ if (CheckLoc == StringRef::npos)
+ return StringRef();
+
+ LineNumber += Buffer.substr(0, CheckLoc + 1).count('\n');
+
+ // Advance to the last possible match we found and try again.
+ Buffer = Buffer.drop_front(CheckLoc + 1);
+ }
+
+ return StringRef();