Replace RE2 import with a dependency

third_party/re2/re2/testing/exhaustive_tester.cc

-// Copyright 2008 The RE2 Authors.  All Rights Reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// Exhaustive testing of regular expression matching.
-
-// Each test picks an alphabet (e.g., "abc"), a maximum string length,
-// a maximum regular expression length, and a maximum number of letters
-// that can appear in the regular expression.  Given these parameters,
-// it tries every possible regular expression and string, verifying that
-// the NFA, DFA, and a trivial backtracking implementation agree about
-// the location of the match.
-
-#include <stdlib.h>
-#include <stdio.h>
-
-#ifndef LOGGING
-#define LOGGING 0
-#endif
-
-#include "util/test.h"
-#include "re2/testing/exhaustive_tester.h"
-#include "re2/testing/tester.h"
-
-DEFINE_bool(show_regexps, false, "show regexps during testing");
-
-DEFINE_int32(max_bad_regexp_inputs, 1,
-             "Stop testing a regular expression after finding this many "
-             "strings that break it.");
-
-// Compiled in debug mode, the usual tests run for over an hour.
-// Have to cut it down to make the unit test machines happy.
-DEFINE_bool(quick_debug_mode, true, "Run fewer tests in debug mode.");
-
-namespace re2 {
-
-static char* escape(const StringPiece& sp) {
-  static char buf[512];
-  char* p = buf;
-  *p++ = '\"';
-  for (int i = 0; i < sp.size(); i++) {
-    if(p+5 >= buf+sizeof buf)
-      LOG(FATAL) << "ExhaustiveTester escape: too long";
-    if(sp[i] == '\\' || sp[i] == '\"') {
-      *p++ = '\\';
-      *p++ = sp[i];
-    } else if(sp[i] == '\n') {
-      *p++ = '\\';
-      *p++ = 'n';
-    } else {
-      *p++ = sp[i];
-    }
-  }
-  *p++ = '\"';
-  *p = '\0';
-  return buf;
-}
-
-static void PrintResult(const RE2& re, const StringPiece& input, RE2::Anchor anchor, StringPiece *m, int n) {
-  if (!re.Match(input, 0, input.size(), anchor, m, n)) {
-    printf("-");
-    return;
-  }
-  for (int i = 0; i < n; i++) {
-    if (i > 0)
-      printf(" ");
-    if (m[i].begin() == NULL)
-      printf("-");
-    else
-      printf("%d-%d", static_cast<int>(m[i].begin() - input.begin()), static_cast<int>(m[i].end() - input.begin()));
-  }
-}
-        
-// Processes a single generated regexp.
-// Compiles it using Regexp interface and PCRE, and then
-// checks that NFA, DFA, and PCRE all return the same results.
-void ExhaustiveTester::HandleRegexp(const string& const_regexp) {
-  regexps_++;
-  string regexp = const_regexp;
-  if (!topwrapper_.empty())
-    regexp = StringPrintf(topwrapper_.c_str(), regexp.c_str());
-
-  if (FLAGS_show_regexps) {
-    printf("\r%s", regexp.c_str());
-    fflush(stdout);
-  }
-
-  if (LOGGING) {
-    // Write out test cases and answers for use in testing
-    // other implementations, such as Go's regexp package.
-    if (randomstrings_)
-      LOG(ERROR) << "Cannot log with random strings.";
-    if (regexps_ == 1) {  // first
-      printf("strings\n");
-      strgen_.Reset();
-      while (strgen_.HasNext())
-        printf("%s\n", escape(strgen_.Next()));
-      printf("regexps\n");
-    }
-    printf("%s\n", escape(regexp));
-
-    RE2 re(regexp);
-    RE2::Options longest;
-    longest.set_longest_match(true);
-    RE2 relongest(regexp, longest);
-    int ngroup = re.NumberOfCapturingGroups()+1;
-    StringPiece* group = new StringPiece[ngroup];
-
-    strgen_.Reset();
-    while (strgen_.HasNext()) {
-      StringPiece input = strgen_.Next();
-      PrintResult(re, input, RE2::ANCHOR_BOTH, group, ngroup);
-      printf(";");
-      PrintResult(re, input, RE2::UNANCHORED, group, ngroup);
-      printf(";");
-      PrintResult(relongest, input, RE2::ANCHOR_BOTH, group, ngroup);
-      printf(";");
-      PrintResult(relongest, input, RE2::UNANCHORED, group, ngroup);
-      printf("\n");
-    }
-    delete[] group;
-    return;
-  }
-
-  Tester tester(regexp);
-  if (tester.error())
-    return;
-
-  strgen_.Reset();
-  strgen_.GenerateNULL();
-  if (randomstrings_)
-    strgen_.Random(stringseed_, stringcount_);
-  int bad_inputs = 0;
-  while (strgen_.HasNext()) {
-    tests_++;
-    if (!tester.TestInput(strgen_.Next())) {
-      failures_++;
-      if (++bad_inputs >= FLAGS_max_bad_regexp_inputs)
-        break;
-    }
-  }
-}
-
-// Runs an exhaustive test on the given parameters.
-void ExhaustiveTest(int maxatoms, int maxops,
-                    const vector<string>& alphabet,
-                    const vector<string>& ops,
-                    int maxstrlen, const vector<string>& stralphabet,
-                    const string& wrapper,
-                    const string& topwrapper) {
-  if (RE2_DEBUG_MODE && FLAGS_quick_debug_mode) {
-    if (maxatoms > 1)
-      maxatoms--;
-    if (maxops > 1)
-      maxops--;
-    if (maxstrlen > 1)
-      maxstrlen--;
-  }
-  ExhaustiveTester t(maxatoms, maxops, alphabet, ops,
-                     maxstrlen, stralphabet, wrapper,
-                     topwrapper);
-  t.Generate();
-  if (!LOGGING) {
-    printf("%d regexps, %d tests, %d failures [%d/%d str]\n",
-           t.regexps(), t.tests(), t.failures(), maxstrlen, (int)stralphabet.size());
-  }
-  EXPECT_EQ(0, t.failures());
-}
-
-// Runs an exhaustive test using the given parameters and
-// the basic egrep operators.
-void EgrepTest(int maxatoms, int maxops, const string& alphabet,
-               int maxstrlen, const string& stralphabet,
-               const string& wrapper) {
-  const char* tops[] = { "", "^(?:%s)", "(?:%s)$", "^(?:%s)$" };
-
-  for (int i = 0; i < arraysize(tops); i++) {
-    ExhaustiveTest(maxatoms, maxops,
-                   Split("", alphabet),
-                   RegexpGenerator::EgrepOps(),
-                   maxstrlen,
-                   Split("", stralphabet),
-                   wrapper,
-                   tops[i]);
-  }
-}
-
-}  // namespace re2