1 // Copyright 2008 The RE2 Authors.  All Rights Reserved.
2 // Use of this source code is governed by a BSD-style
3 // license that can be found in the LICENSE file.
4 
5 // Random testing of regular expression matching.
6 
7 #include <stdio.h>
8 #include <string>
9 #include <vector>
10 
11 #include "util/test.h"
12 #include "util/flags.h"
13 #include "re2/testing/exhaustive_tester.h"
14 
15 DEFINE_FLAG(int, regexpseed, 404, "Random regexp seed.");
16 DEFINE_FLAG(int, regexpcount, 100, "How many random regexps to generate.");
17 DEFINE_FLAG(int, stringseed, 200, "Random string seed.");
18 DEFINE_FLAG(int, stringcount, 100, "How many random strings to generate.");
19 
20 namespace re2 {
21 
22 // Runs a random test on the given parameters.
23 // (Always uses the same random seeds for reproducibility.
24 // Can give different seeds on command line.)
RandomTest(int maxatoms,int maxops,const std::vector<std::string> & alphabet,const std::vector<std::string> & ops,int maxstrlen,const std::vector<std::string> & stralphabet,const std::string & wrapper)25 static void RandomTest(int maxatoms, int maxops,
26                        const std::vector<std::string>& alphabet,
27                        const std::vector<std::string>& ops,
28                        int maxstrlen,
29                        const std::vector<std::string>& stralphabet,
30                        const std::string& wrapper) {
31   // Limit to smaller test cases in debug mode,
32   // because everything is so much slower.
33   if (RE2_DEBUG_MODE) {
34     maxatoms--;
35     maxops--;
36     maxstrlen /= 2;
37   }
38 
39   ExhaustiveTester t(maxatoms, maxops, alphabet, ops,
40                      maxstrlen, stralphabet, wrapper, "");
41   t.RandomStrings(GetFlag(FLAGS_stringseed),
42                   GetFlag(FLAGS_stringcount));
43   t.GenerateRandom(GetFlag(FLAGS_regexpseed),
44                    GetFlag(FLAGS_regexpcount));
45   printf("%d regexps, %d tests, %d failures [%d/%d str]\n",
46          t.regexps(), t.tests(), t.failures(), maxstrlen, (int)stralphabet.size());
47   EXPECT_EQ(0, t.failures());
48 }
49 
50 // Tests random small regexps involving literals and egrep operators.
TEST(Random,SmallEgrepLiterals)51 TEST(Random, SmallEgrepLiterals) {
52   RandomTest(5, 5, Explode("abc."), RegexpGenerator::EgrepOps(),
53              15, Explode("abc"),
54              "");
55 }
56 
57 // Tests random bigger regexps involving literals and egrep operators.
TEST(Random,BigEgrepLiterals)58 TEST(Random, BigEgrepLiterals) {
59   RandomTest(10, 10, Explode("abc."), RegexpGenerator::EgrepOps(),
60              15, Explode("abc"),
61              "");
62 }
63 
64 // Tests random small regexps involving literals, capturing parens,
65 // and egrep operators.
TEST(Random,SmallEgrepCaptures)66 TEST(Random, SmallEgrepCaptures) {
67   RandomTest(5, 5, Split(" ", "a (b) ."), RegexpGenerator::EgrepOps(),
68              15, Explode("abc"),
69              "");
70 }
71 
72 // Tests random bigger regexps involving literals, capturing parens,
73 // and egrep operators.
TEST(Random,BigEgrepCaptures)74 TEST(Random, BigEgrepCaptures) {
75   RandomTest(10, 10, Split(" ", "a (b) ."), RegexpGenerator::EgrepOps(),
76              15, Explode("abc"),
77              "");
78 }
79 
80 // Tests random large complicated expressions, using all the possible
81 // operators, some literals, some parenthesized literals, and predefined
82 // character classes like \d.  (Adding larger character classes would
83 // make for too many possibilities.)
TEST(Random,Complicated)84 TEST(Random, Complicated) {
85   std::vector<std::string> ops = Split(" ",
86     "%s%s %s|%s %s* %s*? %s+ %s+? %s? %s?? "
87     "%s{0} %s{0,} %s{1} %s{1,} %s{0,1} %s{0,2} %s{1,2} "
88     "%s{2} %s{2,} %s{3,4} %s{4,5}");
89 
90   // Use (?:\b) and (?:\B) instead of \b and \B,
91   // because PCRE rejects \b* but accepts (?:\b)*.
92   // Ditto ^ and $.
93   std::vector<std::string> atoms = Split(" ",
94     ". (?:^) (?:$) \\a \\f \\n \\r \\t \\v "
95     "\\d \\D \\s \\S \\w \\W (?:\\b) (?:\\B) "
96     "a (a) b c - \\\\");
97   std::vector<std::string> alphabet = Explode("abc123\001\002\003\t\r\n\v\f\a");
98   RandomTest(10, 10, atoms, ops, 20, alphabet, "");
99 }
100 
101 }  // namespace re2
102