: //===- FileCheck.cpp - Check that File's Contents match what is expected --===//

: //

: //                     The LLVM Compiler Infrastructure

: //

: // This file is distributed under the University of Illinois Open Source

: // License. See LICENSE.TXT for details.

: //

: //===----------------------------------------------------------------------===//

: //

: // FileCheck does a line-by line check of a file that validates whether it

: // contains the expected content.  This is useful for regression tests etc.

: //

: // This program exits with an exit status of 2 on error, exit status of 0 if

: // the file matched the expected contents, and exit status of 1 if it did not

: // contain the expected contents.

: //

: //===----------------------------------------------------------------------===//

: 

: #include "llvm/ADT/SmallString.h"

: #include "llvm/ADT/StringExtras.h"

: #include "llvm/ADT/StringMap.h"

: #include "llvm/ADT/StringSet.h"

: #include "llvm/Support/CommandLine.h"

: #include "llvm/Support/MemoryBuffer.h"

: #include "llvm/Support/PrettyStackTrace.h"

: #include "llvm/Support/Regex.h"

: #include "llvm/Support/Signals.h"

: #include "llvm/Support/SourceMgr.h"

: #include "llvm/Support/raw_ostream.h"

: #include 

: #include 

: #include 

: #include 

: #include 

: #include 

: using namespace llvm;

: 

: static cl::opt

:     CheckFilename(cl::Positional, cl::desc(""), cl::Required);

: 

: static cl::opt

:     InputFilename("input-file", cl::desc("File to check (defaults to stdin)"),

:                   cl::init("-"), cl::value_desc("filename"));

: 

: static cl::list CheckPrefixes(

:     "check-prefix",

:     cl::desc("Prefix to use from check file (defaults to 'CHECK')"));

: static cl::alias CheckPrefixesAlias(

:     "check-prefixes", cl::aliasopt(CheckPrefixes), cl::CommaSeparated,

:     cl::NotHidden,

:     cl::desc(

:         "Alias for -check-prefix permitting multiple comma separated values"));

: 

: static cl::opt NoCanonicalizeWhiteSpace(

:     "strict-whitespace",

:     cl::desc("Do not treat all horizontal whitespace as equivalent"));

: 

: static cl::list 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::list GlobalDefines("D", cl::Prefix,

:     cl::desc("Define a variable to be used in capture patterns."),

:     cl::value_desc("VAR=VALUE"));

: 

: static cl::opt 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."));

: 

: static cl::opt MatchFullLines(

:     "match-full-lines", cl::init(false),

:     cl::desc("Require all positive matches to cover an entire input line.\n"

:              "Allows leading and trailing whitespace if --strict-whitespace\n"

:              "is not also passed."));

: 

: static cl::opt EnableVarScope(

:     "enable-var-scope", cl::init(false),

:     cl::desc("Enables scope for regex variables. Variables with names that\n"

:              "do not start with '$' will be reset at the beginning of\n"

:              "each CHECK-LABEL block."));

: 

: typedef cl::list::const_iterator prefix_iterator;

: 

: //===----------------------------------------------------------------------===//

: // Pattern Handling Code.

: //===----------------------------------------------------------------------===//

: 

: namespace Check {

: enum CheckType {

:   CheckNone = 0,

:   CheckPlain,

:   CheckNext,

:   CheckSame,

:   CheckNot,

:   CheckDAG,

:   CheckLabel,

: 

:   /// Indicates the pattern only matches the end of file. This is used for

:   /// trailing CHECK-NOTs.

:   CheckEOF,

: 

:   /// Marks when parsing found a -NOT check combined with another CHECK suffix.

:   CheckBadNot

: };

: }

: 

: class Pattern {

:   SMLoc PatternLoc;

: 

:   /// A fixed string to match as the pattern or empty if this pattern requires

:   /// a regex match.

:   StringRef FixedStr;

: 

:   /// A regex string to match as the pattern or empty if this pattern requires

:   /// a fixed string to match.

:   std::string RegExStr;

: 

:   /// 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> VariableUses;

: 

:   /// 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 VariableDefs;

: 

:   Check::CheckType CheckTy;

: 

:   /// Contains the number of line this pattern is in.

:   unsigned LineNumber;

: 

: public:

:   explicit Pattern(Check::CheckType Ty) : CheckTy(Ty) {}

: 

:   /// Returns the location in source code.

:   SMLoc getLoc() const { return PatternLoc; }

: 

:   bool ParsePattern(StringRef PatternStr, StringRef Prefix, SourceMgr &SM,

:                     unsigned LineNumber);

:   size_t Match(StringRef Buffer, size_t &MatchLen,

:                StringMap &VariableTable) const;

:   void PrintFailureInfo(const SourceMgr &SM, StringRef Buffer,

:                         const StringMap &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);

:   unsigned

:   ComputeMatchDistance(StringRef Buffer,

:                        const StringMap &VariableTable) const;

:   bool EvaluateExpression(StringRef Expr, std::string &Value) const;

:   size_t FindRegexVarEnd(StringRef Str, SourceMgr &SM);

: };

: 

: /// Parses the given string into the Pattern.

: ///

: /// \p Prefix provides which prefix is being matched, \p SM provides the

: /// SourceMgr used for error reports, and \p 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 Pattern::ParsePattern(StringRef PatternStr, StringRef Prefix,

:                            SourceMgr &SM, unsigned LineNumber) {

:   bool MatchFullLinesHere = MatchFullLines && CheckTy != Check::CheckNot;

: 

:   this->LineNumber = LineNumber;

:   PatternLoc = SMLoc::getFromPointer(PatternStr.data());

: 

:   if (!(NoCanonicalizeWhiteSpace && MatchFullLines))

:     // 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 (!MatchFullLinesHere &&

:       (PatternStr.size() < 2 || (PatternStr.find("{{") == StringRef::npos &&

:                                  PatternStr.find("[[") == StringRef::npos))) {

:     FixedStr = PatternStr;

:     return false;

:   }

: 

:   if (MatchFullLinesHere) {

:     RegExStr += '^';

:     if (!NoCanonicalizeWhiteSpace)

:       RegExStr += " *";

:   }

: 

:   // 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) {

:           if (Name[i] == '$')  // Global vars start with '$'

:             continue;

:           if (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(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);

:   }

: 

:   if (MatchFullLinesHere) {

:     if (!NoCanonicalizeWhiteSpace)

:       RegExStr += " *";

:     RegExStr += '$';

:   }

: 

:   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;

: }

: 

: /// Evaluates expression and stores the result to \p Value.

: ///

: /// Returns true on success and false when the expression has invalid syntax.

: 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;

: }

: 

: /// Matches the pattern string against the input buffer \p 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 \p

: /// MatchLen.

: ///

: /// The \p VariableTable StringMap provides the current values of filecheck

: /// variables and is updated if this match defines new values.

: size_t Pattern::Match(StringRef Buffer, size_t &MatchLen,

:                       StringMap &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 (const auto &VariableUse : VariableUses) {

:       std::string Value;

: 

:       if (VariableUse.first[0] == '@') {

:         if (!EvaluateExpression(VariableUse.first, Value))

:           return StringRef::npos;

:       } else {

:         StringMap::iterator it =

:             VariableTable.find(VariableUse.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() + VariableUse.second + InsertOffset,

:                     Value.begin(), Value.end());

:       InsertOffset += Value.size();

:     }

: 

:     // Match the newly constructed regex.

:     RegExToMatch = TmpStr;

:   }

: 

:   SmallVector 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 (const auto &VariableDef : VariableDefs) {

:     assert(VariableDef.second < MatchInfo.size() && "Internal paren error");

:     VariableTable[VariableDef.first] = MatchInfo[VariableDef.second];

:   }

: 

:   MatchLen = FullMatch.size();

:   return FullMatch.data() - Buffer.data();

: }

: 

: 

: /// Computes an arbitrary estimate for the quality of matching this pattern at

: /// the start of \p Buffer; a distance of zero should correspond to a perfect

: /// match.

: unsigned

: Pattern::ComputeMatchDistance(StringRef Buffer,

:                               const StringMap &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);

: }

: 

: /// Prints additional information about a failure to match involving this

: /// pattern.

: void Pattern::PrintFailureInfo(

:     const SourceMgr &SM, StringRef Buffer,

:     const StringMap &VariableTable) const {

:   // If this was a regular expression using variables, print the current

:   // variable values.

:   if (!VariableUses.empty()) {

:     for (const auto &VariableUse : VariableUses) {

:       SmallString<256> Msg;

:       raw_svector_ostream OS(Msg);

:       StringRef Var = VariableUse.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::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.

:   }

: }

: 

: /// Finds the closing sequence of a regex variable usage or definition.

: ///

: /// \p Str has to point in the beginning of the definition (right after the

: /// opening sequence). Returns the offset of the closing sequence within Str,

: /// or npos if it was not found.

: 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.

: //===----------------------------------------------------------------------===//

: 

: /// A check that we found in the input file.

: struct CheckString {

:   /// The pattern to match.

:   Pattern Pat;

: 

:   /// Which prefix name this check matched.

:   StringRef Prefix;

: 

:   /// The location in the match file that the check string was specified.

:   SMLoc Loc;

: 

:   /// All of the strings that are disallowed from occurring between this match

:   /// string and the previous one (or start of file).

:   std::vector DagNotStrings;

: 

:   CheckString(const Pattern &P, StringRef S, SMLoc L)

:       : Pat(P), Prefix(S), Loc(L) {}

: 

:   size_t Check(const SourceMgr &SM, StringRef Buffer, bool IsLabelScanMode,

:                size_t &MatchLen, StringMap &VariableTable) const;

: 

:   bool CheckNext(const SourceMgr &SM, StringRef Buffer) const;

:   bool CheckSame(const SourceMgr &SM, StringRef Buffer) const;

:   bool CheckNot(const SourceMgr &SM, StringRef Buffer,

:                 const std::vector &NotStrings,

:                 StringMap &VariableTable) const;

:   size_t CheckDag(const SourceMgr &SM, StringRef Buffer,

:                   std::vector &NotStrings,

:                   StringMap &VariableTable) const;

: };

: 

: /// Canonicalize whitespaces in the file. Line endings are replaced with

: /// UNIX-style '\n'.

: static StringRef CanonicalizeFile(MemoryBuffer &MB,

:                                   SmallVectorImpl &OutputBuffer) {

:   OutputBuffer.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 (NoCanonicalizeWhiteSpace || (*Ptr != ' ' && *Ptr != '\t')) {

:       OutputBuffer.push_back(*Ptr);

:       continue;

:     }

: 

:     // Otherwise, add one space and advance over neighboring space.

:     OutputBuffer.push_back(' ');

:     while (Ptr + 1 != End && (Ptr[1] == ' ' || Ptr[1] == '\t'))

:       ++Ptr;

:   }

: 

:   // Add a null byte and then return all but that byte.

:   OutputBuffer.push_back('\0');

:   return StringRef(OutputBuffer.data(), OutputBuffer.size() - 1);

: }

: 

: 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:

:   case Check::CheckBadNot:

:     return 0;

: 

:   case Check::CheckPlain:

:     return sizeof(":") - 1;

: 

:   case Check::CheckNext:

:     return sizeof("-NEXT:") - 1;

: 

:   case Check::CheckSame:

:     return sizeof("-SAME:") - 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("SAME:"))

:     return Check::CheckSame;

: 

:   if (Rest.startswith("NOT:"))

:     return Check::CheckNot;

: 

:   if (Rest.startswith("DAG:"))

:     return Check::CheckDAG;

: 

:   if (Rest.startswith("LABEL:"))

:     return Check::CheckLabel;

: 

:   // You can't combine -NOT with another suffix.

:   if (Rest.startswith("DAG-NOT:") || Rest.startswith("NOT-DAG:") ||

:       Rest.startswith("NEXT-NOT:") || Rest.startswith("NOT-NEXT:") ||

:       Rest.startswith("SAME-NOT:") || Rest.startswith("NOT-SAME:"))

:     return Check::CheckBadNot;

: 

:   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;

: }

: 

: /// Search the buffer for the first prefix in the prefix regular expression.

: ///

: /// This searches the buffer using the provided regular expression, however it

: /// enforces constraints beyond that:

: /// 1) The found prefix must not be a suffix of something that looks like

: ///    a valid prefix.

: /// 2) The found prefix must be followed by a valid check type suffix using \c

: ///    FindCheckType above.

: ///

: /// The first match of the regular expression to satisfy these two is returned,

: /// otherwise an empty StringRef is returned to indicate failure.

: ///

: /// If this routine returns a valid prefix, it will also shrink \p Buffer to

: /// start at the beginning of the returned prefix, increment \p LineNumber for

: /// each new line consumed from \p Buffer, and set \p CheckTy to the type of

: /// check found by examining the suffix.

: ///

: /// If no valid prefix is found, the state of Buffer, LineNumber, and CheckTy

: /// is unspecified.

: static StringRef FindFirstMatchingPrefix(Regex &PrefixRE, StringRef &Buffer,

:                                          unsigned &LineNumber,

:                                          Check::CheckType &CheckTy) {

:   SmallVector Matches;

: 

:   while (!Buffer.empty()) {

:     // Find the first (longest) match using the RE.

:     if (!PrefixRE.match(Buffer, &Matches))

:       // No match at all, bail.

:       return StringRef();

: 

:     StringRef Prefix = Matches[0];

:     Matches.clear();

: 

:     assert(Prefix.data() >= Buffer.data() &&

:            Prefix.data() < Buffer.data() + Buffer.size() &&

:            "Prefix doesn't start inside of buffer!");

:     size_t Loc = Prefix.data() - Buffer.data();

:     StringRef Skipped = Buffer.substr(0, Loc);

:     Buffer = Buffer.drop_front(Loc);

:     LineNumber += Skipped.count('\n');

: 

:     // Check that the matched prefix isn't a suffix of some other check-like

:     // word.

:     // FIXME: This is a very ad-hoc check. it would be better handled in some

:     // other way. Among other things it seems hard to distinguish between

:     // intentional and unintentional uses of this feature.

:     if (Skipped.empty() || !IsPartOfWord(Skipped.back())) {

:       // Now extract the type.

:       CheckTy = FindCheckType(Buffer, Prefix);

: 

:       // If we've found a valid check type for this prefix, we're done.

:       if (CheckTy != Check::CheckNone)

:         return Prefix;

:     }

: 

:     // If we didn't successfully find a prefix, we need to skip this invalid

:     // prefix and continue scanning. We directly skip the prefix that was

:     // matched and any additional parts of that check-like word.

:     Buffer = Buffer.drop_front(SkipWord(Buffer, Prefix.size()));

:   }

: 

:   // We ran out of buffer while skipping partial matches so give up.

:   return StringRef();

: }

: 

: /// Read the check file, which specifies the sequence of expected strings.

: ///

: /// The strings are added to the CheckStrings vector. Returns true in case of

: /// an error, false otherwise.

: static bool ReadCheckFile(SourceMgr &SM, StringRef Buffer, Regex &PrefixRE,

:                           std::vector &CheckStrings) {

:   std::vector ImplicitNegativeChecks;

:   for (const auto &PatternString : ImplicitCheckNot) {

:     // Create a buffer with fake command line content in order to display the

:     // command line option responsible for the specific implicit CHECK-NOT.

:     std::string Prefix = (Twine("-") + ImplicitCheckNot.ArgStr + "='").str();

:     std::string Suffix = "'";

:     std::unique_ptr CmdLine = MemoryBuffer::getMemBufferCopy(

:         Prefix + PatternString + Suffix, "command line");

: 

:     StringRef PatternInBuffer =

:         CmdLine->getBuffer().substr(Prefix.size(), PatternString.size());

:     SM.AddNewSourceBuffer(std::move(CmdLine), SMLoc());

: 

:     ImplicitNegativeChecks.push_back(Pattern(Check::CheckNot));

:     ImplicitNegativeChecks.back().ParsePattern(PatternInBuffer,

:                                                "IMPLICIT-CHECK", SM, 0);

:   }

: 

:   std::vector DagNotMatches = ImplicitNegativeChecks;

: 

:   // LineNumber keeps track of the line on which CheckPrefix instances are

:   // found.

:   unsigned LineNumber = 1;

: 

:   while (1) {

:     Check::CheckType CheckTy;

: 

:     // See if a prefix occurs in the memory buffer.

:     StringRef UsedPrefix = FindFirstMatchingPrefix(PrefixRE, Buffer, LineNumber,

:                                                    CheckTy);

:     if (UsedPrefix.empty())

:       break;

:     assert(UsedPrefix.data() == Buffer.data() &&

:            "Failed to move Buffer's start forward, or pointed prefix outside "

:            "of the buffer!");

: 

:     // Location to use for error messages.

:     const char *UsedPrefixStart = UsedPrefix.data();

: 

:     // Skip the buffer to the end.

:     Buffer = Buffer.drop_front(UsedPrefix.size() + CheckTypeSize(CheckTy));

: 

:     // Complain about useful-looking but unsupported suffixes.

:     if (CheckTy == Check::CheckBadNot) {

:       SM.PrintMessage(SMLoc::getFromPointer(Buffer.data()), SourceMgr::DK_Error,

:                       "unsupported -NOT combo on prefix '" + UsedPrefix + "'");

:       return true;

:     }

: 

:     // Okay, we found the prefix, yay. Remember the rest of the line, but ignore

:     // leading whitespace.

:     if (!(NoCanonicalizeWhiteSpace && MatchFullLines))

:       Buffer = Buffer.substr(Buffer.find_first_not_of(" \t"));

: 

:     // Scan ahead to the end of line.

:     size_t EOL = Buffer.find_first_of("\n\r");

: 

:     // Remember the location of the start of the pattern, for diagnostics.

:     SMLoc PatternLoc = SMLoc::getFromPointer(Buffer.data());

: 

:     // Parse the pattern.

:     Pattern P(CheckTy);

:     if (P.ParsePattern(Buffer.substr(0, EOL), UsedPrefix, SM, LineNumber))

:       return true;

: 

:     // Verify that CHECK-LABEL lines do not define or use variables

:     if ((CheckTy == Check::CheckLabel) && P.hasVariable()) {

:       SM.PrintMessage(

:           SMLoc::getFromPointer(UsedPrefixStart), SourceMgr::DK_Error,

:           "found '" + UsedPrefix + "-LABEL:'"

:                                    " with variable definition or use");

:       return true;

:     }

: 

:     Buffer = Buffer.substr(EOL);

: 

:     // Verify that CHECK-NEXT lines have at least one CHECK line before them.

:     if ((CheckTy == Check::CheckNext || CheckTy == Check::CheckSame) &&

:         CheckStrings.empty()) {

:       StringRef Type = CheckTy == Check::CheckNext ? "NEXT" : "SAME";

:       SM.PrintMessage(SMLoc::getFromPointer(UsedPrefixStart),

:                       SourceMgr::DK_Error,

:                       "found '" + UsedPrefix + "-" + Type +

:                           "' without previous '" + UsedPrefix + ": line");

:       return true;

:     }

: 

:     // Handle CHECK-DAG/-NOT.

:     if (CheckTy == Check::CheckDAG || CheckTy == Check::CheckNot) {

:       DagNotMatches.push_back(P);

:       continue;

:     }

: 

:     // Okay, add the string we captured to the output vector and move on.

:     CheckStrings.emplace_back(P, UsedPrefix, PatternLoc);

:     std::swap(DagNotMatches, CheckStrings.back().DagNotStrings);

:     DagNotMatches = ImplicitNegativeChecks;

:   }

: 

:   // Add an EOF pattern for any trailing CHECK-DAG/-NOTs, and use the first

:   // prefix as a filler for the error message.

:   if (!DagNotMatches.empty()) {

:     CheckStrings.emplace_back(Pattern(Check::CheckEOF), *CheckPrefixes.begin(),

:                               SMLoc::getFromPointer(Buffer.data()));

:     std::swap(DagNotMatches, CheckStrings.back().DagNotStrings);

:   }

: 

:   if (CheckStrings.empty()) {

:     errs() << "error: no check strings found with prefix"

:            << (CheckPrefixes.size() > 1 ? "es " : " ");

:     prefix_iterator I = CheckPrefixes.begin();

:     prefix_iterator E = CheckPrefixes.end();

:     if (I != E) {

:       errs() << "\'" << *I << ":'";

:       ++I;

:     }

:     for (; I != E; ++I)

:       errs() << ", \'" << *I << ":'";

: 

:     errs() << '\n';

:     return true;

:   }

: 

:   return false;

: }

: 

: static void PrintCheckFailed(const SourceMgr &SM, SMLoc Loc, const Pattern &Pat,

:                              StringRef Buffer,

:                              StringMap &VariableTable) {

:   // Otherwise, we have an error, emit an error message.

:   SM.PrintMessage(Loc, SourceMgr::DK_Error,

:                   "expected string not found in input");

: 

:   // Print the "scanning from here" line.  If the current position is at the

:   // end of a line, advance to the start of the next line.

:   Buffer = Buffer.substr(Buffer.find_first_not_of(" \t\n\r"));

: 

:   SM.PrintMessage(SMLoc::getFromPointer(Buffer.data()), SourceMgr::DK_Note,

:                   "scanning from here");

: 

:   // Allow the pattern to print additional information if desired.

:   Pat.PrintFailureInfo(SM, Buffer, VariableTable);

: }

: 

: static void PrintCheckFailed(const SourceMgr &SM, const CheckString &CheckStr,

:                              StringRef Buffer,

:                              StringMap &VariableTable) {

:   PrintCheckFailed(SM, CheckStr.Loc, CheckStr.Pat, Buffer, VariableTable);

: }

: 

: /// Count the number of newlines in the specified range.

: static unsigned CountNumNewlinesBetween(StringRef Range,

:                                         const char *&FirstNewLine) {

:   unsigned NumNewLines = 0;

:   while (1) {

:     // Scan for newline.

:     Range = Range.substr(Range.find_first_of("\n\r"));

:     if (Range.empty())

:       return NumNewLines;

: