/build/llvm-toolchain-snapshot-8~svn345461/lib/Support/FileCheck.cpp

Bug Summary

File:	lib/Support/FileCheck.cpp
Warning:	line 757, column 52 1st function call argument is an uninitialized value
Annotated Source Code

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clang -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name FileCheck.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -mrelocation-model pic -pic-level 2 -mthread-model posix -fmath-errno -masm-verbose -mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu x86-64 -dwarf-column-info -debugger-tuning=gdb -momit-leaf-frame-pointer -ffunction-sections -fdata-sections -resource-dir /usr/lib/llvm-8/lib/clang/8.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-8~svn345461/build-llvm/lib/Support -I /build/llvm-toolchain-snapshot-8~svn345461/lib/Support -I /build/llvm-toolchain-snapshot-8~svn345461/build-llvm/include -I /build/llvm-toolchain-snapshot-8~svn345461/include -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0/backward -internal-isystem /usr/include/clang/8.0.0/include/ -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-8/lib/clang/8.0.0/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-comment -std=c++11 -fdeprecated-macro -fdebug-compilation-dir /build/llvm-toolchain-snapshot-8~svn345461/build-llvm/lib/Support -ferror-limit 19 -fmessage-length 0 -fvisibility-inlines-hidden -fobjc-runtime=gcc -fdiagnostics-show-option -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -o /tmp/scan-build-2018-10-27-211344-32123-1 -x c++ /build/llvm-toolchain-snapshot-8~svn345461/lib/Support/FileCheck.cpp -faddrsig
1//===- FileCheck.cpp - Check that File's Contents match what is expected --===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// FileCheck does a line-by line check of a file that validates whether it
11// contains the expected content.  This is useful for regression tests etc.
12//
13// This file implements most of the API that will be used by the FileCheck utility
14// as well as various unittests.
15//===----------------------------------------------------------------------===//

17#include "llvm/Support/FileCheck.h"
18#include "llvm/ADT/StringSet.h"
19#include <list>
20#include <map>

22using namespace llvm;

24/// Parses the given string into the Pattern.
25///
26/// \p Prefix provides which prefix is being matched, \p SM provides the
27/// SourceMgr used for error reports, and \p LineNumber is the line number in
28/// the input file from which the pattern string was read. Returns true in
29/// case of an error, false otherwise.
30bool FileCheckPattern::ParsePattern(StringRef PatternStr, StringRef Prefix,
                         SourceMgr &SM, unsigned LineNumber,
                         const FileCheckRequest &Req) {
bool MatchFullLinesHere = Req.MatchFullLines && CheckTy != Check::CheckNot;

this->LineNumber = LineNumber;
PatternLoc = SMLoc::getFromPointer(PatternStr.data());

if (!(Req.NoCanonicalizeWhiteSpace && Req.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() && CheckTy != Check::CheckEmpty) {
  SM.PrintMessage(PatternLoc, SourceMgr::DK_Error,
                  "found empty check string with prefix '" + Prefix + ":'");
  return true;
}

if (!PatternStr.empty() && CheckTy == Check::CheckEmpty) {
  SM.PrintMessage(
      PatternLoc, SourceMgr::DK_Error,
      "found non-empty check string for empty check with prefix '" + Prefix +
          ":'");
  return true;
}

if (CheckTy == Check::CheckEmpty) {
  RegExStr = "(\n$)";
  return false;
}

// 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 (!Req.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<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);
}

if (MatchFullLinesHere) {
  if (!Req.NoCanonicalizeWhiteSpace)
    RegExStr += " *";
  RegExStr += '$';
}

return false;
220}

222bool FileCheckPattern::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;
234}

236void FileCheckPattern::AddBackrefToRegEx(unsigned BackrefNum) {
assert(BackrefNum >= 1 && BackrefNum <= 9 && "Invalid backref number")((BackrefNum >= 1 && BackrefNum <= 9 &&
 "Invalid backref number") ? static_cast<void> (0) : __assert_fail
 ("BackrefNum >= 1 && BackrefNum <= 9 && \"Invalid backref number\""
, "/build/llvm-toolchain-snapshot-8~svn345461/lib/Support/FileCheck.cpp"
, 237, __PRETTY_FUNCTION__));
std::string Backref = std::string("\\") + std::string(1, '0' + BackrefNum);
RegExStr += Backref;
240}

242/// Evaluates expression and stores the result to \p Value.
243///
244/// Returns true on success and false when the expression has invalid syntax.
245bool FileCheckPattern::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;
261}

263/// Matches the pattern string against the input buffer \p Buffer
264///
265/// This returns the position that is matched or npos if there is no match. If
266/// there is a match, the size of the matched string is returned in \p
267/// MatchLen.
268///
269/// The \p VariableTable StringMap provides the current values of filecheck
270/// variables and is updated if this match defines new values.
271size_t FileCheckPattern::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 (const auto &VariableUse : VariableUses) {
    std::string Value;

    if (VariableUse.first[0] == '@') {
      if (!EvaluateExpression(VariableUse.first, Value))
        return StringRef::npos;
    } else {
      StringMap<StringRef>::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<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")((!MatchInfo.empty() && "Didn't get any match") ? static_cast
<void> (0) : __assert_fail ("!MatchInfo.empty() && \"Didn't get any match\""
, "/build/llvm-toolchain-snapshot-8~svn345461/lib/Support/FileCheck.cpp"
, 327, __PRETTY_FUNCTION__));
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")((VariableDef.second < MatchInfo.size() && "Internal paren error"
) ? static_cast<void> (0) : __assert_fail ("VariableDef.second < MatchInfo.size() && \"Internal paren error\""
, "/build/llvm-toolchain-snapshot-8~svn345461/lib/Support/FileCheck.cpp"
, 332, __PRETTY_FUNCTION__));
  VariableTable[VariableDef.first] = MatchInfo[VariableDef.second];
}

// Like CHECK-NEXT, CHECK-EMPTY's match range is considered to start after
// the required preceding newline, which is consumed by the pattern in the
// case of CHECK-EMPTY but not CHECK-NEXT.
size_t MatchStartSkip = CheckTy == Check::CheckEmpty;
MatchLen = FullMatch.size() - MatchStartSkip;
return FullMatch.data() - Buffer.data() + MatchStartSkip;
342}


345/// Computes an arbitrary estimate for the quality of matching this pattern at
346/// the start of \p Buffer; a distance of zero should correspond to a perfect
347/// match.
348unsigned
349FileCheckPattern::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);
365}

367void FileCheckPattern::PrintVariableUses(const SourceMgr &SM, StringRef Buffer,
                              const StringMap<StringRef> &VariableTable,
                              SMRange MatchRange) 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<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) << "\"";
      }
    }

    if (MatchRange.isValid())
      SM.PrintMessage(MatchRange.Start, SourceMgr::DK_Note, OS.str(),
                      {MatchRange});
    else
      SM.PrintMessage(SMLoc::getFromPointer(Buffer.data()),
                      SourceMgr::DK_Note, OS.str());
  }
}
409}

411void FileCheckPattern::PrintFuzzyMatch(
  const SourceMgr &SM, StringRef Buffer,
  const StringMap<StringRef> &VariableTable) const {
// 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.
}
453}

455/// Finds the closing sequence of a regex variable usage or definition.
456///
457/// \p Str has to point in the beginning of the definition (right after the
458/// opening sequence). Returns the offset of the closing sequence within Str,
459/// or npos if it was not found.
460size_t FileCheckPattern::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;
496}

498/// Canonicalize whitespaces in the file. Line endings are replaced with
499/// UNIX-style '\n'.
500StringRef
501llvm::FileCheck::CanonicalizeFile(MemoryBuffer &MB,
                                SmallVectorImpl<char> &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 (Req.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);
528}

530static bool IsPartOfWord(char c) {
return (isalnum(c) || c == '-' || c == '_');
532}

534// Get the size of the prefix extension.
535static size_t CheckTypeSize(Check::FileCheckType 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::CheckEmpty:
  return sizeof("-EMPTY:") - 1;

case Check::CheckEOF:
  llvm_unreachable("Should not be using EOF size")::llvm::llvm_unreachable_internal("Should not be using EOF size"
, "/build/llvm-toolchain-snapshot-8~svn345461/lib/Support/FileCheck.cpp"
, 563);
}

llvm_unreachable("Bad check type")::llvm::llvm_unreachable_internal("Bad check type", "/build/llvm-toolchain-snapshot-8~svn345461/lib/Support/FileCheck.cpp"
, 566);
567}

569// Get a description of the type.
570static std::string CheckTypeName(StringRef Prefix, Check::FileCheckType Ty) {
switch (Ty) {
case Check::CheckNone:
  return "invalid";
case Check::CheckPlain:
  return Prefix;
case Check::CheckNext:
  return Prefix.str() + "-NEXT";
case Check::CheckSame:
  return Prefix.str() + "-SAME";
case Check::CheckNot:
  return Prefix.str() + "-NOT";
case Check::CheckDAG:
  return Prefix.str() + "-DAG";
case Check::CheckLabel:
  return Prefix.str() + "-LABEL";
case Check::CheckEmpty:
  return Prefix.str() + "-EMPTY";
case Check::CheckEOF:
  return "implicit EOF";
case Check::CheckBadNot:
  return "bad NOT";
}
llvm_unreachable("unknown FileCheckType")::llvm::llvm_unreachable_internal("unknown FileCheckType", "/build/llvm-toolchain-snapshot-8~svn345461/lib/Support/FileCheck.cpp"
, 593);
594}

596static Check::FileCheckType FindCheckType(StringRef Buffer, StringRef Prefix) {
if (Buffer.size() <= Prefix.size())
  return Check::CheckNone;

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;

if (Rest.startswith("EMPTY:"))
  return Check::CheckEmpty;

// 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:") ||
    Rest.startswith("EMPTY-NOT:") || Rest.startswith("NOT-EMPTY:"))
  return Check::CheckBadNot;

return Check::CheckNone;
636}

638// From the given position, find the next character after the word.
639static size_t SkipWord(StringRef Str, size_t Loc) {
while (Loc < Str.size() && IsPartOfWord(Str[Loc]))
  ++Loc;
return Loc;
643}

645/// Search the buffer for the first prefix in the prefix regular expression.
646///
647/// This searches the buffer using the provided regular expression, however it
648/// enforces constraints beyond that:
649/// 1) The found prefix must not be a suffix of something that looks like
650///    a valid prefix.
651/// 2) The found prefix must be followed by a valid check type suffix using \c
652///    FindCheckType above.
653///
654/// The first match of the regular expression to satisfy these two is returned,
655/// otherwise an empty StringRef is returned to indicate failure.
656///
657/// If this routine returns a valid prefix, it will also shrink \p Buffer to
658/// start at the beginning of the returned prefix, increment \p LineNumber for
659/// each new line consumed from \p Buffer, and set \p CheckTy to the type of
660/// check found by examining the suffix.
661///
662/// If no valid prefix is found, the state of Buffer, LineNumber, and CheckTy
663/// is unspecified.
664static StringRef FindFirstMatchingPrefix(Regex &PrefixRE, StringRef &Buffer,
                                       unsigned &LineNumber,
                                       Check::FileCheckType &CheckTy) {
SmallVector<StringRef, 2> Matches;

while (!Buffer.empty()) {
4
←
Assuming the condition is false→
5
←
Loop condition is false. Execution continues on line 707→
  // 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() && Prefix.data() <
 Buffer.data() + Buffer.size() && "Prefix doesn't start inside of buffer!"
) ? static_cast<void> (0) : __assert_fail ("Prefix.data() >= Buffer.data() && Prefix.data() < Buffer.data() + Buffer.size() && \"Prefix doesn't start inside of buffer!\""
, "/build/llvm-toolchain-snapshot-8~svn345461/lib/Support/FileCheck.cpp"
, 680, __PRETTY_FUNCTION__))
         Prefix.data() < Buffer.data() + Buffer.size() &&((Prefix.data() >= Buffer.data() && Prefix.data() <
 Buffer.data() + Buffer.size() && "Prefix doesn't start inside of buffer!"
) ? static_cast<void> (0) : __assert_fail ("Prefix.data() >= Buffer.data() && Prefix.data() < Buffer.data() + Buffer.size() && \"Prefix doesn't start inside of buffer!\""
, "/build/llvm-toolchain-snapshot-8~svn345461/lib/Support/FileCheck.cpp"
, 680, __PRETTY_FUNCTION__))
         "Prefix doesn't start inside of buffer!")((Prefix.data() >= Buffer.data() && Prefix.data() <
 Buffer.data() + Buffer.size() && "Prefix doesn't start inside of buffer!"
) ? static_cast<void> (0) : __assert_fail ("Prefix.data() >= Buffer.data() && Prefix.data() < Buffer.data() + Buffer.size() && \"Prefix doesn't start inside of buffer!\""
, "/build/llvm-toolchain-snapshot-8~svn345461/lib/Support/FileCheck.cpp"
, 680, __PRETTY_FUNCTION__));
  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();
6
←
Returning without writing to 'CheckTy'→
708}

710/// Read the check file, which specifies the sequence of expected strings.
711///
712/// The strings are added to the CheckStrings vector. Returns true in case of
713/// an error, false otherwise.
714bool llvm::FileCheck::ReadCheckFile(SourceMgr &SM, StringRef Buffer,
                                  Regex &PrefixRE,
                                  std::vector<FileCheckString> &CheckStrings) {
std::vector<FileCheckPattern> ImplicitNegativeChecks;
for (const auto &PatternString : Req.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 = "-implicit-check-not='";
  std::string Suffix = "'";
  std::unique_ptr<MemoryBuffer> 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(FileCheckPattern(Check::CheckNot));
  ImplicitNegativeChecks.back().ParsePattern(PatternInBuffer,
                                             "IMPLICIT-CHECK", SM, 0, Req);
}

std::vector<FileCheckPattern> DagNotMatches = ImplicitNegativeChecks;

// LineNumber keeps track of the line on which CheckPrefix instances are
// found.
unsigned LineNumber = 1;

while (1) {
1
Loop condition is true.  Entering loop body→
  Check::FileCheckType CheckTy;
2
←
'CheckTy' declared without an initial value→

  // See if a prefix occurs in the memory buffer.
  StringRef UsedPrefix = FindFirstMatchingPrefix(PrefixRE, Buffer, LineNumber,
3
←
Calling 'FindFirstMatchingPrefix'→
7
←
Returning from 'FindFirstMatchingPrefix'→
                                                 CheckTy);
  if (UsedPrefix.empty())
8
←
Assuming the condition is false→
9
←
Taking false branch→
    break;
  assert(UsedPrefix.data() == Buffer.data() &&((UsedPrefix.data() == Buffer.data() && "Failed to move Buffer's start forward, or pointed prefix outside "
 "of the buffer!") ? static_cast<void> (0) : __assert_fail
 ("UsedPrefix.data() == Buffer.data() && \"Failed to move Buffer's start forward, or pointed prefix outside \" \"of the buffer!\""
, "/build/llvm-toolchain-snapshot-8~svn345461/lib/Support/FileCheck.cpp"
, 751, __PRETTY_FUNCTION__))
         "Failed to move Buffer's start forward, or pointed prefix outside "((UsedPrefix.data() == Buffer.data() && "Failed to move Buffer's start forward, or pointed prefix outside "
 "of the buffer!") ? static_cast<void> (0) : __assert_fail
 ("UsedPrefix.data() == Buffer.data() && \"Failed to move Buffer's start forward, or pointed prefix outside \" \"of the buffer!\""
, "/build/llvm-toolchain-snapshot-8~svn345461/lib/Support/FileCheck.cpp"
, 751, __PRETTY_FUNCTION__))
         "of the buffer!")((UsedPrefix.data() == Buffer.data() && "Failed to move Buffer's start forward, or pointed prefix outside "
 "of the buffer!") ? static_cast<void> (0) : __assert_fail
 ("UsedPrefix.data() == Buffer.data() && \"Failed to move Buffer's start forward, or pointed prefix outside \" \"of the buffer!\""
, "/build/llvm-toolchain-snapshot-8~svn345461/lib/Support/FileCheck.cpp"
, 751, __PRETTY_FUNCTION__));

  // 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));
10
←
1st function call argument is an uninitialized value

  // 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 (!(Req.NoCanonicalizeWhiteSpace && Req.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.
  FileCheckPattern P(CheckTy);
  if (P.ParsePattern(Buffer.substr(0, EOL), UsedPrefix, SM, LineNumber, Req))
    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/SAME/EMPTY lines have at least one CHECK line before them.
  if ((CheckTy == Check::CheckNext || CheckTy == Check::CheckSame ||
       CheckTy == Check::CheckEmpty) &&
      CheckStrings.empty()) {
    StringRef Type = CheckTy == Check::CheckNext
                         ? "NEXT"
                         : CheckTy == Check::CheckEmpty ? "EMPTY" : "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(FileCheckPattern(Check::CheckEOF), *Req.CheckPrefixes.begin(),
                            SMLoc::getFromPointer(Buffer.data()));
  std::swap(DagNotMatches, CheckStrings.back().DagNotStrings);
}

if (CheckStrings.empty()) {
  errs() << "error: no check strings found with prefix"
         << (Req.CheckPrefixes.size() > 1 ? "es " : " ");
  auto I = Req.CheckPrefixes.begin();
  auto E = Req.CheckPrefixes.end();
  if (I != E) {
    errs() << "\'" << *I << ":'";
    ++I;
  }
  for (; I != E; ++I)
    errs() << ", \'" << *I << ":'";

  errs() << '\n';
  return true;
}

return false;
844}

846static void PrintMatch(bool ExpectedMatch, const SourceMgr &SM,
                     StringRef Prefix, SMLoc Loc, const FileCheckPattern &Pat,
                     StringRef Buffer, StringMap<StringRef> &VariableTable,
                     size_t MatchPos, size_t MatchLen,
                     const FileCheckRequest &Req) {
if (ExpectedMatch) {
  if (!Req.Verbose)
    return;
  if (!Req.VerboseVerbose && Pat.getCheckTy() == Check::CheckEOF)
    return;
}
SMLoc MatchStart = SMLoc::getFromPointer(Buffer.data() + MatchPos);
SMLoc MatchEnd = SMLoc::getFromPointer(Buffer.data() + MatchPos + MatchLen);
SMRange MatchRange(MatchStart, MatchEnd);
SM.PrintMessage(
    Loc, ExpectedMatch ? SourceMgr::DK_Remark : SourceMgr::DK_Error,
    CheckTypeName(Prefix, Pat.getCheckTy()) + ": " +
        (ExpectedMatch ? "expected" : "excluded") +
        " string found in input");
SM.PrintMessage(MatchStart, SourceMgr::DK_Note, "found here", {MatchRange});
Pat.PrintVariableUses(SM, Buffer, VariableTable, MatchRange);
867}

869static void PrintMatch(bool ExpectedMatch, const SourceMgr &SM,
                     const FileCheckString &CheckStr, StringRef Buffer,
                     StringMap<StringRef> &VariableTable, size_t MatchPos,
                     size_t MatchLen, FileCheckRequest &Req) {
PrintMatch(ExpectedMatch, SM, CheckStr.Prefix, CheckStr.Loc, CheckStr.Pat,
           Buffer, VariableTable, MatchPos, MatchLen, Req);
875}

877static void PrintNoMatch(bool ExpectedMatch, const SourceMgr &SM,
                       StringRef Prefix, SMLoc Loc, const FileCheckPattern &Pat,
                       StringRef Buffer,
                       StringMap<StringRef> &VariableTable,
                       bool VerboseVerbose) {
if (!ExpectedMatch && !VerboseVerbose)
  return;

// Otherwise, we have an error, emit an error message.
SM.PrintMessage(Loc,
                ExpectedMatch ? SourceMgr::DK_Error : SourceMgr::DK_Remark,
                CheckTypeName(Prefix, Pat.getCheckTy()) + ": " +
                    (ExpectedMatch ? "expected" : "excluded") +
                    " 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.PrintVariableUses(SM, Buffer, VariableTable);
if (ExpectedMatch)
  Pat.PrintFuzzyMatch(SM, Buffer, VariableTable);
903}

905static void PrintNoMatch(bool ExpectedMatch, const SourceMgr &SM,
                       const FileCheckString &CheckStr, StringRef Buffer,
                       StringMap<StringRef> &VariableTable,
                       bool VerboseVerbose) {
PrintNoMatch(ExpectedMatch, SM, CheckStr.Prefix, CheckStr.Loc, CheckStr.Pat,
             Buffer, VariableTable, VerboseVerbose);
911}

913/// Count the number of newlines in the specified range.
914static 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;

  ++NumNewLines;

  // Handle \n\r and \r\n as a single newline.
  if (Range.size() > 1 && (Range[1] == '\n' || Range[1] == '\r') &&
      (Range[0] != Range[1]))
    Range = Range.substr(1);
  Range = Range.substr(1);

  if (NumNewLines == 1)
    FirstNewLine = Range.begin();
}
934}

936/// Match check string and its "not strings" and/or "dag strings".
937size_t FileCheckString::Check(const SourceMgr &SM, StringRef Buffer,
                        bool IsLabelScanMode, size_t &MatchLen,
                        StringMap<StringRef> &VariableTable,
                        FileCheckRequest &Req) const {
size_t LastPos = 0;
std::vector<const FileCheckPattern *> NotStrings;

// IsLabelScanMode is true when we are scanning forward to find CHECK-LABEL
// bounds; we have not processed variable definitions within the bounded block
// yet so cannot handle any final CHECK-DAG yet; this is handled when going
// over the block again (including the last CHECK-LABEL) in normal mode.
if (!IsLabelScanMode) {
  // Match "dag strings" (with mixed "not strings" if any).
  LastPos = CheckDag(SM, Buffer, NotStrings, VariableTable, Req);
  if (LastPos == StringRef::npos)
    return StringRef::npos;
}

// Match itself from the last position after matching CHECK-DAG.
StringRef MatchBuffer = Buffer.substr(LastPos);
size_t MatchPos = Pat.Match(MatchBuffer, MatchLen, VariableTable);
if (MatchPos == StringRef::npos) {
  PrintNoMatch(true, SM, *this, MatchBuffer, VariableTable, Req.VerboseVerbose);
  return StringRef::npos;
}
PrintMatch(true, SM, *this, MatchBuffer, VariableTable, MatchPos, MatchLen, Req);

// Similar to the above, in "label-scan mode" we can't yet handle CHECK-NEXT
// or CHECK-NOT
if (!IsLabelScanMode) {
  StringRef SkippedRegion = Buffer.substr(LastPos, MatchPos);

  // If this check is a "CHECK-NEXT", verify that the previous match was on
  // the previous line (i.e. that there is one newline between them).
  if (CheckNext(SM, SkippedRegion))
    return StringRef::npos;

  // If this check is a "CHECK-SAME", verify that the previous match was on
  // the same line (i.e. that there is no newline between them).
  if (CheckSame(SM, SkippedRegion))
    return StringRef::npos;

  // If this match had "not strings", verify that they don't exist in the
  // skipped region.
  if (CheckNot(SM, SkippedRegion, NotStrings, VariableTable, Req))
    return StringRef::npos;
}

return LastPos + MatchPos;
986}

988/// Verify there is a single line in the given buffer.
989bool FileCheckString::CheckNext(const SourceMgr &SM, StringRef Buffer) const {
if (Pat.getCheckTy() != Check::CheckNext &&
    Pat.getCheckTy() != Check::CheckEmpty)
  return false;

Twine CheckName =
    Prefix +
    Twine(Pat.getCheckTy() == Check::CheckEmpty ? "-EMPTY" : "-NEXT");

// Count the number of newlines between the previous match and this one.
assert(Buffer.data() !=((Buffer.data() != SM.getMemoryBuffer(SM.FindBufferContainingLoc
( SMLoc::getFromPointer(Buffer.data()))) ->getBufferStart(
) && "CHECK-NEXT and CHECK-EMPTY can't be the first check in a file"
) ? static_cast<void> (0) : __assert_fail ("Buffer.data() != SM.getMemoryBuffer(SM.FindBufferContainingLoc( SMLoc::getFromPointer(Buffer.data()))) ->getBufferStart() && \"CHECK-NEXT and CHECK-EMPTY can't be the first check in a file\""
, "/build/llvm-toolchain-snapshot-8~svn345461/lib/Support/FileCheck.cpp"
, 1003, __PRETTY_FUNCTION__))
           SM.getMemoryBuffer(SM.FindBufferContainingLoc(((Buffer.data() != SM.getMemoryBuffer(SM.FindBufferContainingLoc
( SMLoc::getFromPointer(Buffer.data()))) ->getBufferStart(
) && "CHECK-NEXT and CHECK-EMPTY can't be the first check in a file"
) ? static_cast<void> (0) : __assert_fail ("Buffer.data() != SM.getMemoryBuffer(SM.FindBufferContainingLoc( SMLoc::getFromPointer(Buffer.data()))) ->getBufferStart() && \"CHECK-NEXT and CHECK-EMPTY can't be the first check in a file\""
, "/build/llvm-toolchain-snapshot-8~svn345461/lib/Support/FileCheck.cpp"
, 1003, __PRETTY_FUNCTION__))
                                  SMLoc::getFromPointer(Buffer.data())))((Buffer.data() != SM.getMemoryBuffer(SM.FindBufferContainingLoc
( SMLoc::getFromPointer(Buffer.data()))) ->getBufferStart(
) && "CHECK-NEXT and CHECK-EMPTY can't be the first check in a file"
) ? static_cast<void> (0) : __assert_fail ("Buffer.data() != SM.getMemoryBuffer(SM.FindBufferContainingLoc( SMLoc::getFromPointer(Buffer.data()))) ->getBufferStart() && \"CHECK-NEXT and CHECK-EMPTY can't be the first check in a file\""
, "/build/llvm-toolchain-snapshot-8~svn345461/lib/Support/FileCheck.cpp"
, 1003, __PRETTY_FUNCTION__))
               ->getBufferStart() &&((Buffer.data() != SM.getMemoryBuffer(SM.FindBufferContainingLoc
( SMLoc::getFromPointer(Buffer.data()))) ->getBufferStart(
) && "CHECK-NEXT and CHECK-EMPTY can't be the first check in a file"
) ? static_cast<void> (0) : __assert_fail ("Buffer.data() != SM.getMemoryBuffer(SM.FindBufferContainingLoc( SMLoc::getFromPointer(Buffer.data()))) ->getBufferStart() && \"CHECK-NEXT and CHECK-EMPTY can't be the first check in a file\""
, "/build/llvm-toolchain-snapshot-8~svn345461/lib/Support/FileCheck.cpp"
, 1003, __PRETTY_FUNCTION__))
       "CHECK-NEXT and CHECK-EMPTY can't be the first check in a file")((Buffer.data() != SM.getMemoryBuffer(SM.FindBufferContainingLoc
( SMLoc::getFromPointer(Buffer.data()))) ->getBufferStart(
) && "CHECK-NEXT and CHECK-EMPTY can't be the first check in a file"
) ? static_cast<void> (0) : __assert_fail ("Buffer.data() != SM.getMemoryBuffer(SM.FindBufferContainingLoc( SMLoc::getFromPointer(Buffer.data()))) ->getBufferStart() && \"CHECK-NEXT and CHECK-EMPTY can't be the first check in a file\""
, "/build/llvm-toolchain-snapshot-8~svn345461/lib/Support/FileCheck.cpp"
, 1003, __PRETTY_FUNCTION__));

const char *FirstNewLine = nullptr;
unsigned NumNewLines = CountNumNewlinesBetween(Buffer, FirstNewLine);

if (NumNewLines == 0) {
  SM.PrintMessage(Loc, SourceMgr::DK_Error,
                  CheckName + ": is on the same line as previous match");
  SM.PrintMessage(SMLoc::getFromPointer(Buffer.end()), SourceMgr::DK_Note,
                  "'next' match was here");
  SM.PrintMessage(SMLoc::getFromPointer(Buffer.data()), SourceMgr::DK_Note,
                  "previous match ended here");
  return true;
}

if (NumNewLines != 1) {
  SM.PrintMessage(Loc, SourceMgr::DK_Error,
                  CheckName +
                      ": is not on the line after the previous match");
  SM.PrintMessage(SMLoc::getFromPointer(Buffer.end()), SourceMgr::DK_Note,
                  "'next' match was here");
  SM.PrintMessage(SMLoc::getFromPointer(Buffer.data()), SourceMgr::DK_Note,
                  "previous match ended here");
  SM.PrintMessage(SMLoc::getFromPointer(FirstNewLine), SourceMgr::DK_Note,
                  "non-matching line after previous match is here");
  return true;
}

return false;
1032}

1034/// Verify there is no newline in the given buffer.
1035bool FileCheckString::CheckSame(const SourceMgr &SM, StringRef Buffer) const {
if (Pat.getCheckTy() != Check::CheckSame)
  return false;

// Count the number of newlines between the previous match and this one.
assert(Buffer.data() !=((Buffer.data() != SM.getMemoryBuffer(SM.FindBufferContainingLoc
( SMLoc::getFromPointer(Buffer.data()))) ->getBufferStart(
) && "CHECK-SAME can't be the first check in a file")
 ? static_cast<void> (0) : __assert_fail ("Buffer.data() != SM.getMemoryBuffer(SM.FindBufferContainingLoc( SMLoc::getFromPointer(Buffer.data()))) ->getBufferStart() && \"CHECK-SAME can't be the first check in a file\""
, "/build/llvm-toolchain-snapshot-8~svn345461/lib/Support/FileCheck.cpp"
, 1044, __PRETTY_FUNCTION__))
           SM.getMemoryBuffer(SM.FindBufferContainingLoc(((Buffer.data() != SM.getMemoryBuffer(SM.FindBufferContainingLoc
( SMLoc::getFromPointer(Buffer.data()))) ->getBufferStart(
) && "CHECK-SAME can't be the first check in a file")
 ? static_cast<void> (0) : __assert_fail ("Buffer.data() != SM.getMemoryBuffer(SM.FindBufferContainingLoc( SMLoc::getFromPointer(Buffer.data()))) ->getBufferStart() && \"CHECK-SAME can't be the first check in a file\""
, "/build/llvm-toolchain-snapshot-8~svn345461/lib/Support/FileCheck.cpp"
, 1044, __PRETTY_FUNCTION__))
                                  SMLoc::getFromPointer(Buffer.data())))((Buffer.data() != SM.getMemoryBuffer(SM.FindBufferContainingLoc
( SMLoc::getFromPointer(Buffer.data()))) ->getBufferStart(
) && "CHECK-SAME can't be the first check in a file")
 ? static_cast<void> (0) : __assert_fail ("Buffer.data() != SM.getMemoryBuffer(SM.FindBufferContainingLoc( SMLoc::getFromPointer(Buffer.data()))) ->getBufferStart() && \"CHECK-SAME can't be the first check in a file\""
, "/build/llvm-toolchain-snapshot-8~svn345461/lib/Support/FileCheck.cpp"
, 1044, __PRETTY_FUNCTION__))
               ->getBufferStart() &&((Buffer.data() != SM.getMemoryBuffer(SM.FindBufferContainingLoc
( SMLoc::getFromPointer(Buffer.data()))) ->getBufferStart(
) && "CHECK-SAME can't be the first check in a file")
 ? static_cast<void> (0) : __assert_fail ("Buffer.data() != SM.getMemoryBuffer(SM.FindBufferContainingLoc( SMLoc::getFromPointer(Buffer.data()))) ->getBufferStart() && \"CHECK-SAME can't be the first check in a file\""
, "/build/llvm-toolchain-snapshot-8~svn345461/lib/Support/FileCheck.cpp"
, 1044, __PRETTY_FUNCTION__))
       "CHECK-SAME can't be the first check in a file")((Buffer.data() != SM.getMemoryBuffer(SM.FindBufferContainingLoc
( SMLoc::getFromPointer(Buffer.data()))) ->getBufferStart(
) && "CHECK-SAME can't be the first check in a file")
 ? static_cast<void> (0) : __assert_fail ("Buffer.data() != SM.getMemoryBuffer(SM.FindBufferContainingLoc( SMLoc::getFromPointer(Buffer.data()))) ->getBufferStart() && \"CHECK-SAME can't be the first check in a file\""
, "/build/llvm-toolchain-snapshot-8~svn345461/lib/Support/FileCheck.cpp"
, 1044, __PRETTY_FUNCTION__));

const char *FirstNewLine = nullptr;
unsigned NumNewLines = CountNumNewlinesBetween(Buffer, FirstNewLine);

if (NumNewLines != 0) {
  SM.PrintMessage(Loc, SourceMgr::DK_Error,
                  Prefix +
                      "-SAME: is not on the same line as the previous match");
  SM.PrintMessage(SMLoc::getFromPointer(Buffer.end()), SourceMgr::DK_Note,
                  "'next' match was here");
  SM.PrintMessage(SMLoc::getFromPointer(Buffer.data()), SourceMgr::DK_Note,
                  "previous match ended here");
  return true;
}

return false;
1061}

1063/// Verify there's no "not strings" in the given buffer.
1064bool FileCheckString::CheckNot(const SourceMgr &SM, StringRef Buffer,
                         const std::vector<const FileCheckPattern *> &NotStrings,
                         StringMap<StringRef> &VariableTable,
                         const FileCheckRequest &Req) const {
for (const FileCheckPattern *Pat : NotStrings) {
  assert((Pat->getCheckTy() == Check::CheckNot) && "Expect CHECK-NOT!")(((Pat->getCheckTy() == Check::CheckNot) && "Expect CHECK-NOT!"
) ? static_cast<void> (0) : __assert_fail ("(Pat->getCheckTy() == Check::CheckNot) && \"Expect CHECK-NOT!\""
, "/build/llvm-toolchain-snapshot-8~svn345461/lib/Support/FileCheck.cpp"
, 1069, __PRETTY_FUNCTION__));

  size_t MatchLen = 0;
  size_t Pos = Pat->Match(Buffer, MatchLen, VariableTable);

  if (Pos == StringRef::npos) {
    PrintNoMatch(false, SM, Prefix, Pat->getLoc(), *Pat, Buffer,
                 VariableTable, Req.VerboseVerbose);
    continue;
  }

  PrintMatch(false, SM, Prefix, Pat->getLoc(), *Pat, Buffer, VariableTable,
             Pos, MatchLen, Req);

  return true;
}

return false;
1087}

1089/// Match "dag strings" and their mixed "not strings".
1090size_t FileCheckString::CheckDag(const SourceMgr &SM, StringRef Buffer,
                           std::vector<const FileCheckPattern *> &NotStrings,
                           StringMap<StringRef> &VariableTable,
                           const FileCheckRequest &Req) const {
if (DagNotStrings.empty())
  return 0;

// The start of the search range.
size_t StartPos = 0;

struct MatchRange {
  size_t Pos;
  size_t End;
};
// A sorted list of ranges for non-overlapping CHECK-DAG matches.  Match
// ranges are erased from this list once they are no longer in the search
// range.
std::list<MatchRange> MatchRanges;

// We need PatItr and PatEnd later for detecting the end of a CHECK-DAG
// group, so we don't use a range-based for loop here.
for (auto PatItr = DagNotStrings.begin(), PatEnd = DagNotStrings.end();
     PatItr != PatEnd; ++PatItr) {
  const FileCheckPattern &Pat = *PatItr;
  assert((Pat.getCheckTy() == Check::CheckDAG ||(((Pat.getCheckTy() == Check::CheckDAG || Pat.getCheckTy() ==
 Check::CheckNot) && "Invalid CHECK-DAG or CHECK-NOT!"
) ? static_cast<void> (0) : __assert_fail ("(Pat.getCheckTy() == Check::CheckDAG || Pat.getCheckTy() == Check::CheckNot) && \"Invalid CHECK-DAG or CHECK-NOT!\""
, "/build/llvm-toolchain-snapshot-8~svn345461/lib/Support/FileCheck.cpp"
, 1116, __PRETTY_FUNCTION__))
          Pat.getCheckTy() == Check::CheckNot) &&(((Pat.getCheckTy() == Check::CheckDAG || Pat.getCheckTy() ==
 Check::CheckNot) && "Invalid CHECK-DAG or CHECK-NOT!"
) ? static_cast<void> (0) : __assert_fail ("(Pat.getCheckTy() == Check::CheckDAG || Pat.getCheckTy() == Check::CheckNot) && \"Invalid CHECK-DAG or CHECK-NOT!\""
, "/build/llvm-toolchain-snapshot-8~svn345461/lib/Support/FileCheck.cpp"
, 1116, __PRETTY_FUNCTION__))
         "Invalid CHECK-DAG or CHECK-NOT!")(((Pat.getCheckTy() == Check::CheckDAG || Pat.getCheckTy() ==
 Check::CheckNot) && "Invalid CHECK-DAG or CHECK-NOT!"
) ? static_cast<void> (0) : __assert_fail ("(Pat.getCheckTy() == Check::CheckDAG || Pat.getCheckTy() == Check::CheckNot) && \"Invalid CHECK-DAG or CHECK-NOT!\""
, "/build/llvm-toolchain-snapshot-8~svn345461/lib/Support/FileCheck.cpp"
, 1116, __PRETTY_FUNCTION__));

  if (Pat.getCheckTy() == Check::CheckNot) {
    NotStrings.push_back(&Pat);
    continue;
  }

  assert((Pat.getCheckTy() == Check::CheckDAG) && "Expect CHECK-DAG!")(((Pat.getCheckTy() == Check::CheckDAG) && "Expect CHECK-DAG!"
) ? static_cast<void> (0) : __assert_fail ("(Pat.getCheckTy() == Check::CheckDAG) && \"Expect CHECK-DAG!\""
, "/build/llvm-toolchain-snapshot-8~svn345461/lib/Support/FileCheck.cpp"
, 1123, __PRETTY_FUNCTION__));

  // CHECK-DAG always matches from the start.
  size_t MatchLen = 0, MatchPos = StartPos;

  // Search for a match that doesn't overlap a previous match in this
  // CHECK-DAG group.
  for (auto MI = MatchRanges.begin(), ME = MatchRanges.end(); true; ++MI) {
    StringRef MatchBuffer = Buffer.substr(MatchPos);
    size_t MatchPosBuf = Pat.Match(MatchBuffer, MatchLen, VariableTable);
    // With a group of CHECK-DAGs, a single mismatching means the match on
    // that group of CHECK-DAGs fails immediately.
    if (MatchPosBuf == StringRef::npos) {
      PrintNoMatch(true, SM, Prefix, Pat.getLoc(), Pat, MatchBuffer,
                   VariableTable, Req.VerboseVerbose);
      return StringRef::npos;
    }
    // Re-calc it as the offset relative to the start of the original string.
    MatchPos += MatchPosBuf;
    if (Req.VerboseVerbose)
      PrintMatch(true, SM, Prefix, Pat.getLoc(), Pat, Buffer, VariableTable,
                 MatchPos, MatchLen, Req);
    MatchRange M{MatchPos, MatchPos + MatchLen};
    if (Req.AllowDeprecatedDagOverlap) {
      // We don't need to track all matches in this mode, so we just maintain
      // one match range that encompasses the current CHECK-DAG group's
      // matches.
      if (MatchRanges.empty())
        MatchRanges.insert(MatchRanges.end(), M);
      else {
        auto Block = MatchRanges.begin();
        Block->Pos = std::min(Block->Pos, M.Pos);
        Block->End = std::max(Block->End, M.End);
      }
      break;
    }
    // Iterate previous matches until overlapping match or insertion point.
    bool Overlap = false;
    for (; MI != ME; ++MI) {
      if (M.Pos < MI->End) {
        // !Overlap => New match has no overlap and is before this old match.
        // Overlap => New match overlaps this old match.
        Overlap = MI->Pos < M.End;
        break;
      }
    }
    if (!Overlap) {
      // Insert non-overlapping match into list.
      MatchRanges.insert(MI, M);
      break;
    }
    if (Req.VerboseVerbose) {
      SMLoc OldStart = SMLoc::getFromPointer(Buffer.data() + MI->Pos);
      SMLoc OldEnd = SMLoc::getFromPointer(Buffer.data() + MI->End);
      SMRange OldRange(OldStart, OldEnd);
      SM.PrintMessage(OldStart, SourceMgr::DK_Note,
                      "match discarded, overlaps earlier DAG match here",
                      {OldRange});
    }
    MatchPos = MI->End;
  }
  if (!Req.VerboseVerbose)
    PrintMatch(true, SM, Prefix, Pat.getLoc(), Pat, Buffer, VariableTable,
               MatchPos, MatchLen, Req);

  // Handle the end of a CHECK-DAG group.
  if (std::next(PatItr) == PatEnd ||
      std::next(PatItr)->getCheckTy() == Check::CheckNot) {
    if (!NotStrings.empty()) {
      // If there are CHECK-NOTs between two CHECK-DAGs or from CHECK to
      // CHECK-DAG, verify that there are no 'not' strings occurred in that
      // region.
      StringRef SkippedRegion =
          Buffer.slice(StartPos, MatchRanges.begin()->Pos);
      if (CheckNot(SM, SkippedRegion, NotStrings, VariableTable, Req))
        return StringRef::npos;
      // Clear "not strings".
      NotStrings.clear();
    }
    // All subsequent CHECK-DAGs and CHECK-NOTs should be matched from the
    // end of this CHECK-DAG group's match range.
    StartPos = MatchRanges.rbegin()->End;
    // Don't waste time checking for (impossible) overlaps before that.
    MatchRanges.clear();
  }
}

return StartPos;
1211}

1213// A check prefix must contain only alphanumeric, hyphens and underscores.
1214static bool ValidateCheckPrefix(StringRef CheckPrefix) {
Regex Validator("^[a-zA-Z0-9_-]*$");
return Validator.match(CheckPrefix);
1217}

1219bool llvm::FileCheck::ValidateCheckPrefixes() {
StringSet<> PrefixSet;

for (StringRef Prefix : Req.CheckPrefixes) {
  // Reject empty prefixes.
  if (Prefix == "")
    return false;

  if (!PrefixSet.insert(Prefix).second)
    return false;

  if (!ValidateCheckPrefix(Prefix))
    return false;
}

return true;
1235}

1237// Combines the check prefixes into a single regex so that we can efficiently
1238// scan for any of the set.
1239//
1240// The semantics are that the longest-match wins which matches our regex
1241// library.
1242Regex llvm::FileCheck::buildCheckPrefixRegex() {
// I don't think there's a way to specify an initial value for cl::list,
// so if nothing was specified, add the default
if (Req.CheckPrefixes.empty())
  Req.CheckPrefixes.push_back("CHECK");

// We already validated the contents of CheckPrefixes so just concatenate
// them as alternatives.
SmallString<32> PrefixRegexStr;
for (StringRef Prefix : Req.CheckPrefixes) {
  if (Prefix != Req.CheckPrefixes.front())
    PrefixRegexStr.push_back('|');

  PrefixRegexStr.append(Prefix);
}

return Regex(PrefixRegexStr);
1259}

1261// Remove local variables from \p VariableTable. Global variables
1262// (start with '$') are preserved.
1263static void ClearLocalVars(StringMap<StringRef> &VariableTable) {
SmallVector<StringRef, 16> LocalVars;
for (const auto &Var : VariableTable)
  if (Var.first()[0] != '$')
    LocalVars.push_back(Var.first());

for (const auto &Var : LocalVars)
  VariableTable.erase(Var);
1271}

1273/// Check the input to FileCheck provided in the \p Buffer against the \p
1274/// CheckStrings read from the check file.
1275///
1276/// Returns false if the input fails to satisfy the checks.
1277bool llvm::FileCheck::CheckInput(SourceMgr &SM, StringRef Buffer,
              ArrayRef<FileCheckString> CheckStrings) {
bool ChecksFailed = false;

/// VariableTable - This holds all the current filecheck variables.
StringMap<StringRef> VariableTable;

for (const auto& Def : Req.GlobalDefines)
  VariableTable.insert(StringRef(Def).split('='));

unsigned i = 0, j = 0, e = CheckStrings.size();
while (true) {
  StringRef CheckRegion;
  if (j == e) {
    CheckRegion = Buffer;
  } else {
    const FileCheckString &CheckLabelStr = CheckStrings[j];
    if (CheckLabelStr.Pat.getCheckTy() != Check::CheckLabel) {
      ++j;
      continue;
    }

    // Scan to next CHECK-LABEL match, ignoring CHECK-NOT and CHECK-DAG
    size_t MatchLabelLen = 0;
    size_t MatchLabelPos =
        CheckLabelStr.Check(SM, Buffer, true, MatchLabelLen, VariableTable,
                            Req);
    if (MatchLabelPos == StringRef::npos)
      // Immediately bail of CHECK-LABEL fails, nothing else we can do.
      return false;

    CheckRegion = Buffer.substr(0, MatchLabelPos + MatchLabelLen);
    Buffer = Buffer.substr(MatchLabelPos + MatchLabelLen);
    ++j;
  }

  if (Req.EnableVarScope)
    ClearLocalVars(VariableTable);

  for (; i != j; ++i) {
    const FileCheckString &CheckStr = CheckStrings[i];

    // Check each string within the scanned region, including a second check
    // of any final CHECK-LABEL (to verify CHECK-NOT and CHECK-DAG)
    size_t MatchLen = 0;
    size_t MatchPos =
        CheckStr.Check(SM, CheckRegion, false, MatchLen, VariableTable, Req);

    if (MatchPos == StringRef::npos) {
      ChecksFailed = true;
      i = j;
      break;
    }

    CheckRegion = CheckRegion.substr(MatchPos + MatchLen);
  }

  if (j == e)
    break;
}

// Success if no checks failed.
return !ChecksFailed;
1340}