1 // Copyright 2006-2008 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 #include <vector>
6 #include "util/test.h"
7 #include "re2/prog.h"
8 #include "re2/re2.h"
9 #include "re2/regexp.h"
10 #include "re2/testing/regexp_generator.h"
11 #include "re2/testing/string_generator.h"
12
13 namespace re2 {
14
15 // Test that C++ strings are compared as uint8s, not int8s.
16 // PossibleMatchRange doesn't depend on this, but callers probably will.
TEST(CplusplusStrings,EightBit)17 TEST(CplusplusStrings, EightBit) {
18 string s = "\x70";
19 string t = "\xA0";
20 EXPECT_LT(s, t);
21 }
22
23 struct PrefixTest {
24 const char* regexp;
25 int maxlen;
26 const char* min;
27 const char* max;
28 };
29
30 static PrefixTest tests[] = {
31 { "", 10, "", "", },
32 { "Abcdef", 10, "Abcdef", "Abcdef" },
33 { "abc(def|ghi)", 10, "abcdef", "abcghi" },
34 { "a+hello", 10, "aa", "ahello" },
35 { "a*hello", 10, "a", "hello" },
36 { "def|abc", 10, "abc", "def" },
37 { "a(b)(c)[d]", 10, "abcd", "abcd" },
38 { "ab(cab|cat)", 10, "abcab", "abcat" },
39 { "ab(cab|ca)x", 10, "abcabx", "abcax" },
40 { "(ab|x)(c|de)", 10, "abc", "xde" },
41 { "(ab|x)?(c|z)?", 10, "", "z" },
42 { "[^\\s\\S]", 10, "", "" },
43 { "(abc)+", 5, "abc", "abcac" },
44 { "(abc)+", 2, "ab", "ac" },
45 { "(abc)+", 1, "a", "b" },
46 { "[a\xC3\xA1]", 4, "a", "\xC3\xA1" },
47 { "a*", 10, "", "ab" },
48
49 { "(?i)Abcdef", 10, "ABCDEF", "abcdef" },
50 { "(?i)abc(def|ghi)", 10, "ABCDEF", "abcghi" },
51 { "(?i)a+hello", 10, "AA", "ahello" },
52 { "(?i)a*hello", 10, "A", "hello" },
53 { "(?i)def|abc", 10, "ABC", "def" },
54 { "(?i)a(b)(c)[d]", 10, "ABCD", "abcd" },
55 { "(?i)ab(cab|cat)", 10, "ABCAB", "abcat" },
56 { "(?i)ab(cab|ca)x", 10, "ABCABX", "abcax" },
57 { "(?i)(ab|x)(c|de)", 10, "ABC", "xde" },
58 { "(?i)(ab|x)?(c|z)?", 10, "", "z" },
59 { "(?i)[^\\s\\S]", 10, "", "" },
60 { "(?i)(abc)+", 5, "ABC", "abcac" },
61 { "(?i)(abc)+", 2, "AB", "ac" },
62 { "(?i)(abc)+", 1, "A", "b" },
63 { "(?i)[a\xC3\xA1]", 4, "A", "\xC3\xA1" },
64 { "(?i)a*", 10, "", "ab" },
65 { "(?i)A*", 10, "", "ab" },
66
67 { "\\AAbcdef", 10, "Abcdef", "Abcdef" },
68 { "\\Aabc(def|ghi)", 10, "abcdef", "abcghi" },
69 { "\\Aa+hello", 10, "aa", "ahello" },
70 { "\\Aa*hello", 10, "a", "hello" },
71 { "\\Adef|abc", 10, "abc", "def" },
72 { "\\Aa(b)(c)[d]", 10, "abcd", "abcd" },
73 { "\\Aab(cab|cat)", 10, "abcab", "abcat" },
74 { "\\Aab(cab|ca)x", 10, "abcabx", "abcax" },
75 { "\\A(ab|x)(c|de)", 10, "abc", "xde" },
76 { "\\A(ab|x)?(c|z)?", 10, "", "z" },
77 { "\\A[^\\s\\S]", 10, "", "" },
78 { "\\A(abc)+", 5, "abc", "abcac" },
79 { "\\A(abc)+", 2, "ab", "ac" },
80 { "\\A(abc)+", 1, "a", "b" },
81 { "\\A[a\xC3\xA1]", 4, "a", "\xC3\xA1" },
82 { "\\Aa*", 10, "", "ab" },
83
84 { "(?i)\\AAbcdef", 10, "ABCDEF", "abcdef" },
85 { "(?i)\\Aabc(def|ghi)", 10, "ABCDEF", "abcghi" },
86 { "(?i)\\Aa+hello", 10, "AA", "ahello" },
87 { "(?i)\\Aa*hello", 10, "A", "hello" },
88 { "(?i)\\Adef|abc", 10, "ABC", "def" },
89 { "(?i)\\Aa(b)(c)[d]", 10, "ABCD", "abcd" },
90 { "(?i)\\Aab(cab|cat)", 10, "ABCAB", "abcat" },
91 { "(?i)\\Aab(cab|ca)x", 10, "ABCABX", "abcax" },
92 { "(?i)\\A(ab|x)(c|de)", 10, "ABC", "xde" },
93 { "(?i)\\A(ab|x)?(c|z)?", 10, "", "z" },
94 { "(?i)\\A[^\\s\\S]", 10, "", "" },
95 { "(?i)\\A(abc)+", 5, "ABC", "abcac" },
96 { "(?i)\\A(abc)+", 2, "AB", "ac" },
97 { "(?i)\\A(abc)+", 1, "A", "b" },
98 { "(?i)\\A[a\xC3\xA1]", 4, "A", "\xC3\xA1" },
99 { "(?i)\\Aa*", 10, "", "ab" },
100 { "(?i)\\AA*", 10, "", "ab" },
101 };
102
TEST(PossibleMatchRange,HandWritten)103 TEST(PossibleMatchRange, HandWritten) {
104 for (int i = 0; i < arraysize(tests); i++) {
105 for (int j = 0; j < 2; j++) {
106 const PrefixTest& t = tests[i];
107 string min, max;
108 if (j == 0) {
109 LOG(INFO) << "Checking regexp=" << CEscape(t.regexp);
110 Regexp* re = Regexp::Parse(t.regexp, Regexp::LikePerl, NULL);
111 CHECK(re);
112 Prog* prog = re->CompileToProg(0);
113 CHECK(prog);
114 CHECK(prog->PossibleMatchRange(&min, &max, t.maxlen))
115 << " " << t.regexp;
116 delete prog;
117 re->Decref();
118 } else {
119 CHECK(RE2(t.regexp).PossibleMatchRange(&min, &max, t.maxlen));
120 }
121 EXPECT_EQ(t.min, min) << t.regexp;
122 EXPECT_EQ(t.max, max) << t.regexp;
123 }
124 }
125 }
126
127 // Test cases where PossibleMatchRange should return false.
TEST(PossibleMatchRange,Failures)128 TEST(PossibleMatchRange, Failures) {
129 string min, max;
130
131 // Fails because no room to write max.
132 EXPECT_FALSE(RE2("abc").PossibleMatchRange(&min, &max, 0));
133
134 // Fails because there is no max -- any non-empty string matches
135 // or begins a match. Have to use Latin-1 input, because there
136 // are no valid UTF-8 strings beginning with byte 0xFF.
137 EXPECT_FALSE(RE2("[\\s\\S]+", RE2::Latin1).
138 PossibleMatchRange(&min, &max, 10))
139 << "min=" << CEscape(min) << ", max=" << CEscape(max);
140 EXPECT_FALSE(RE2("[\\0-\xFF]+", RE2::Latin1).
141 PossibleMatchRange(&min, &max, 10))
142 << "min=" << CEscape(min) << ", max=" << CEscape(max);
143 EXPECT_FALSE(RE2(".+hello", RE2::Latin1).
144 PossibleMatchRange(&min, &max, 10))
145 << "min=" << CEscape(min) << ", max=" << CEscape(max);
146 EXPECT_FALSE(RE2(".*hello", RE2::Latin1).
147 PossibleMatchRange(&min, &max, 10))
148 << "min=" << CEscape(min) << ", max=" << CEscape(max);
149 EXPECT_FALSE(RE2(".*", RE2::Latin1).
150 PossibleMatchRange(&min, &max, 10))
151 << "min=" << CEscape(min) << ", max=" << CEscape(max);
152 EXPECT_FALSE(RE2("\\C*").
153 PossibleMatchRange(&min, &max, 10))
154 << "min=" << CEscape(min) << ", max=" << CEscape(max);
155
156 // Fails because it's a malformed regexp.
157 EXPECT_FALSE(RE2("*hello").PossibleMatchRange(&min, &max, 10))
158 << "min=" << CEscape(min) << ", max=" << CEscape(max);
159 }
160
161 // Exhaustive test: generate all regexps within parameters,
162 // then generate all strings of a given length over a given alphabet,
163 // then check that the prefix information agrees with whether
164 // the regexp matches each of the strings.
165 class PossibleMatchTester : public RegexpGenerator {
166 public:
PossibleMatchTester(int maxatoms,int maxops,const vector<string> & alphabet,const vector<string> & ops,int maxstrlen,const vector<string> & stralphabet)167 PossibleMatchTester(int maxatoms,
168 int maxops,
169 const vector<string>& alphabet,
170 const vector<string>& ops,
171 int maxstrlen,
172 const vector<string>& stralphabet)
173 : RegexpGenerator(maxatoms, maxops, alphabet, ops),
174 strgen_(maxstrlen, stralphabet),
175 regexps_(0), tests_(0) { }
176
regexps()177 int regexps() { return regexps_; }
tests()178 int tests() { return tests_; }
179
180 // Needed for RegexpGenerator interface.
181 void HandleRegexp(const string& regexp);
182
183 private:
184 StringGenerator strgen_;
185
186 int regexps_; // Number of HandleRegexp calls
187 int tests_; // Number of regexp tests.
188
189 DISALLOW_EVIL_CONSTRUCTORS(PossibleMatchTester);
190 };
191
192 // Processes a single generated regexp.
193 // Checks that all accepted strings agree with the prefix range.
HandleRegexp(const string & regexp)194 void PossibleMatchTester::HandleRegexp(const string& regexp) {
195 regexps_++;
196
197 VLOG(3) << CEscape(regexp);
198
199 RE2 re(regexp, RE2::Latin1);
200 CHECK_EQ(re.error(), "");
201
202 string min, max;
203 if(!re.PossibleMatchRange(&min, &max, 10)) {
204 // There's no good max for "\\C*". Can't use strcmp
205 // because sometimes it gets embedded in more
206 // complicated expressions.
207 if(strstr(regexp.c_str(), "\\C*"))
208 return;
209 LOG(QFATAL) << "PossibleMatchRange failed on: " << CEscape(regexp);
210 }
211
212 strgen_.Reset();
213 while (strgen_.HasNext()) {
214 const StringPiece& s = strgen_.Next();
215 tests_++;
216 if (!RE2::FullMatch(s, re))
217 continue;
218 CHECK_GE(s, min) << " regexp: " << regexp << " max: " << max;
219 CHECK_LE(s, max) << " regexp: " << regexp << " min: " << min;
220 }
221 }
222
TEST(PossibleMatchRange,Exhaustive)223 TEST(PossibleMatchRange, Exhaustive) {
224 int natom = 3;
225 int noperator = 3;
226 int stringlen = 5;
227 if (DEBUG_MODE) {
228 natom = 2;
229 noperator = 3;
230 stringlen = 3;
231 }
232 PossibleMatchTester t(natom, noperator, Split(" ", "a b [0-9]"),
233 RegexpGenerator::EgrepOps(),
234 stringlen, Explode("ab4"));
235 t.Generate();
236 LOG(INFO) << t.regexps() << " regexps, "
237 << t.tests() << " tests";
238 }
239
240 } // namespace re2
241