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// Copyright 2009 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.
#include <string>
#include "util/test.h"
#include "util/logging.h"
#include "re2/prog.h"
#include "re2/regexp.h"
namespace re2 {
struct PrefixTest {
const char* regexp;
bool return_value;
const char* prefix;
bool foldcase;
const char* suffix;
};
static PrefixTest tests[] = {
// Empty cases.
{ "", false },
{ "(?m)^", false },
{ "(?-m)^", false },
// If the regexp has no ^, there's no required prefix.
{ "abc", false },
// If the regexp immediately goes into
// something not a literal match, there's no required prefix.
{ "^a*", false },
{ "^(abc)", false },
// Otherwise, it should work.
{ "^abc$", true, "abc", false, "(?-m:$)" },
{ "^abc", true, "abc", false, "" },
{ "^(?i)abc", true, "abc", true, "" },
{ "^abcd*", true, "abc", false, "d*" },
{ "^[Aa][Bb]cd*", true, "ab", true, "cd*" },
{ "^ab[Cc]d*", true, "ab", false, "[Cc]d*" },
{ "^☺abc", true, "☺abc", false, "" },
};
TEST(RequiredPrefix, SimpleTests) {
for (size_t i = 0; i < arraysize(tests); i++) {
const PrefixTest& t = tests[i];
for (size_t j = 0; j < 2; j++) {
Regexp::ParseFlags flags = Regexp::LikePerl;
if (j == 0)
flags = flags | Regexp::Latin1;
Regexp* re = Regexp::Parse(t.regexp, flags, NULL);
ASSERT_TRUE(re != NULL) << " " << t.regexp;
std::string p;
bool f;
Regexp* s;
ASSERT_EQ(t.return_value, re->RequiredPrefix(&p, &f, &s))
<< " " << t.regexp << " " << (j == 0 ? "latin1" : "utf8")
<< " " << re->Dump();
if (t.return_value) {
ASSERT_EQ(p, std::string(t.prefix))
<< " " << t.regexp << " " << (j == 0 ? "latin1" : "utf8");
ASSERT_EQ(f, t.foldcase)
<< " " << t.regexp << " " << (j == 0 ? "latin1" : "utf8");
ASSERT_EQ(s->ToString(), std::string(t.suffix))
<< " " << t.regexp << " " << (j == 0 ? "latin1" : "utf8");
s->Decref();
}
re->Decref();
}
}
}
static PrefixTest for_accel_tests[] = {
// Empty cases.
{ "", false },
{ "(?m)^", false },
{ "(?-m)^", false },
// If the regexp has a ^, there's no required prefix.
{ "^abc", false },
// If the regexp immediately goes into
// something not a literal match, there's no required prefix.
{ "a*", false },
// Unlike RequiredPrefix(), RequiredPrefixForAccel() can "see through"
// capturing groups, but doesn't try to glue prefix fragments together.
{ "(a?)def", false },
{ "(ab?)def", true, "a", false },
{ "(abc?)def", true, "ab", false },
{ "(()a)def", false },
{ "((a)b)def", true, "a", false },
{ "((ab)c)def", true, "ab", false },
// Otherwise, it should work.
{ "abc$", true, "abc", false },
{ "abc", true, "abc", false },
{ "(?i)abc", true, "abc", true },
{ "abcd*", true, "abc", false },
{ "[Aa][Bb]cd*", true, "ab", true },
{ "ab[Cc]d*", true, "ab", false },
{ "☺abc", true, "☺abc", false },
};
TEST(RequiredPrefixForAccel, SimpleTests) {
for (size_t i = 0; i < arraysize(for_accel_tests); i++) {
const PrefixTest& t = for_accel_tests[i];
for (size_t j = 0; j < 2; j++) {
Regexp::ParseFlags flags = Regexp::LikePerl;
if (j == 0)
flags = flags | Regexp::Latin1;
Regexp* re = Regexp::Parse(t.regexp, flags, NULL);
ASSERT_TRUE(re != NULL) << " " << t.regexp;
std::string p;
bool f;
ASSERT_EQ(t.return_value, re->RequiredPrefixForAccel(&p, &f))
<< " " << t.regexp << " " << (j == 0 ? "latin1" : "utf8")
<< " " << re->Dump();
if (t.return_value) {
ASSERT_EQ(p, std::string(t.prefix))
<< " " << t.regexp << " " << (j == 0 ? "latin1" : "utf8");
ASSERT_EQ(f, t.foldcase)
<< " " << t.regexp << " " << (j == 0 ? "latin1" : "utf8");
}
re->Decref();
}
}
}
TEST(RequiredPrefixForAccel, CaseFoldingForKAndS) {
Regexp* re;
std::string p;
bool f;
// With Latin-1 encoding, `(?i)` prefixes can include 'k' and 's'.
re = Regexp::Parse("(?i)KLM", Regexp::LikePerl|Regexp::Latin1, NULL);
ASSERT_TRUE(re != NULL);
ASSERT_TRUE(re->RequiredPrefixForAccel(&p, &f));
ASSERT_EQ(p, "klm");
ASSERT_EQ(f, true);
re->Decref();
re = Regexp::Parse("(?i)STU", Regexp::LikePerl|Regexp::Latin1, NULL);
ASSERT_TRUE(re != NULL);
ASSERT_TRUE(re->RequiredPrefixForAccel(&p, &f));
ASSERT_EQ(p, "stu");
ASSERT_EQ(f, true);
re->Decref();
// With UTF-8 encoding, `(?i)` prefixes can't include 'k' and 's'.
// This is because they match U+212A and U+017F, respectively, and
// so the parser ends up emitting character classes, not literals.
re = Regexp::Parse("(?i)KLM", Regexp::LikePerl, NULL);
ASSERT_TRUE(re != NULL);
ASSERT_FALSE(re->RequiredPrefixForAccel(&p, &f));
re->Decref();
re = Regexp::Parse("(?i)STU", Regexp::LikePerl, NULL);
ASSERT_TRUE(re != NULL);
ASSERT_FALSE(re->RequiredPrefixForAccel(&p, &f));
re->Decref();
}
static const char* prefix_accel_tests[] = {
"aababc\\d+",
"(?i)AABABC\\d+",
};
TEST(PrefixAccel, SimpleTests) {
for (size_t i = 0; i < arraysize(prefix_accel_tests); i++) {
const char* pattern = prefix_accel_tests[i];
Regexp* re = Regexp::Parse(pattern, Regexp::LikePerl, NULL);
ASSERT_TRUE(re != NULL);
Prog* prog = re->CompileToProg(0);
ASSERT_TRUE(prog != NULL);
ASSERT_TRUE(prog->can_prefix_accel());
for (int j = 0; j < 100; j++) {
std::string text(j, 'a');
const char* p = reinterpret_cast<const char*>(
prog->PrefixAccel(text.data(), text.size()));
EXPECT_TRUE(p == NULL);
text.append("aababc");
for (int k = 0; k < 100; k++) {
text.append(k, 'a');
p = reinterpret_cast<const char*>(
prog->PrefixAccel(text.data(), text.size()));
EXPECT_EQ(j, p - text.data());
}
}
delete prog;
re->Decref();
}
}
} // namespace re2
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