Mercurial > hg > CbC > CbC_llvm

comparison lib/Support/Regex.cpp @ 3:9ad51c7bc036

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
1st commit. remove git dir and add all files.
author Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
date Wed, 15 May 2013 06:43:32 +0900
parents
children
comparison
equal deleted inserted replaced
-1:000000000000 3:9ad51c7bc036
1 //===-- Regex.cpp - Regular Expression matcher implementation -------------===//
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 // This file implements a POSIX regular expression matcher.
11 //
12 //===----------------------------------------------------------------------===//
13
14 #include "llvm/Support/Regex.h"
15 #include "regex_impl.h"
16 #include "llvm/ADT/SmallVector.h"
17 #include "llvm/Support/ErrorHandling.h"
18 #include "llvm/Support/raw_ostream.h"
19 #include <string>
20 using namespace llvm;
21
22 Regex::Regex(StringRef regex, unsigned Flags) {
23 unsigned flags = 0;
24 preg = new llvm_regex();
25 preg->re_endp = regex.end();
26 if (Flags & IgnoreCase)
27 flags |= REG_ICASE;
28 if (Flags & Newline)
29 flags |= REG_NEWLINE;
30 if (!(Flags & BasicRegex))
31 flags |= REG_EXTENDED;
32 error = llvm_regcomp(preg, regex.data(), flags|REG_PEND);
33 }
34
35 Regex::~Regex() {
36 llvm_regfree(preg);
37 delete preg;
38 }
39
40 bool Regex::isValid(std::string &Error) {
41 if (!error)
42 return true;
43
44 size_t len = llvm_regerror(error, preg, NULL, 0);
45
46 Error.resize(len);
47 llvm_regerror(error, preg, &Error[0], len);
48 return false;
49 }
50
51 /// getNumMatches - In a valid regex, return the number of parenthesized
52 /// matches it contains.
53 unsigned Regex::getNumMatches() const {
54 return preg->re_nsub;
55 }
56
57 bool Regex::match(StringRef String, SmallVectorImpl<StringRef> *Matches){
58 unsigned nmatch = Matches ? preg->re_nsub+1 : 0;
59
60 // pmatch needs to have at least one element.
61 SmallVector<llvm_regmatch_t, 8> pm;
62 pm.resize(nmatch > 0 ? nmatch : 1);
63 pm[0].rm_so = 0;
64 pm[0].rm_eo = String.size();
65
66 int rc = llvm_regexec(preg, String.data(), nmatch, pm.data(), REG_STARTEND);
67
68 if (rc == REG_NOMATCH)
69 return false;
70 if (rc != 0) {
71 // regexec can fail due to invalid pattern or running out of memory.
72 error = rc;
73 return false;
74 }
75
76 // There was a match.
77
78 if (Matches) { // match position requested
79 Matches->clear();
80
81 for (unsigned i = 0; i != nmatch; ++i) {
82 if (pm[i].rm_so == -1) {
83 // this group didn't match
84 Matches->push_back(StringRef());
85 continue;
86 }
87 assert(pm[i].rm_eo >= pm[i].rm_so);
88 Matches->push_back(StringRef(String.data()+pm[i].rm_so,
89 pm[i].rm_eo-pm[i].rm_so));
90 }
91 }
92
93 return true;
94 }
95
96 std::string Regex::sub(StringRef Repl, StringRef String,
97 std::string *Error) {
98 SmallVector<StringRef, 8> Matches;
99
100 // Reset error, if given.
101 if (Error && !Error->empty()) *Error = "";
102
103 // Return the input if there was no match.
104 if (!match(String, &Matches))
105 return String;
106
107 // Otherwise splice in the replacement string, starting with the prefix before
108 // the match.
109 std::string Res(String.begin(), Matches[0].begin());
110
111 // Then the replacement string, honoring possible substitutions.
112 while (!Repl.empty()) {
113 // Skip to the next escape.
114 std::pair<StringRef, StringRef> Split = Repl.split('\\');
115
116 // Add the skipped substring.
117 Res += Split.first;
118
119 // Check for terminimation and trailing backslash.
120 if (Split.second.empty()) {
121 if (Repl.size() != Split.first.size() &&
122 Error && Error->empty())
123 *Error = "replacement string contained trailing backslash";
124 break;
125 }
126
127 // Otherwise update the replacement string and interpret escapes.
128 Repl = Split.second;
129
130 // FIXME: We should have a StringExtras function for mapping C99 escapes.
131 switch (Repl[0]) {
132 // Treat all unrecognized characters as self-quoting.
133 default:
134 Res += Repl[0];
135 Repl = Repl.substr(1);
136 break;
137
138 // Single character escapes.
139 case 't':
140 Res += '\t';
141 Repl = Repl.substr(1);
142 break;
143 case 'n':
144 Res += '\n';
145 Repl = Repl.substr(1);
146 break;
147
148 // Decimal escapes are backreferences.
149 case '0': case '1': case '2': case '3': case '4':
150 case '5': case '6': case '7': case '8': case '9': {
151 // Extract the backreference number.
152 StringRef Ref = Repl.slice(0, Repl.find_first_not_of("0123456789"));
153 Repl = Repl.substr(Ref.size());
154
155 unsigned RefValue;
156 if (!Ref.getAsInteger(10, RefValue) &&
157 RefValue < Matches.size())
158 Res += Matches[RefValue];
159 else if (Error && Error->empty())
160 *Error = "invalid backreference string '" + Ref.str() + "'";
161 break;
162 }
163 }
164 }
165
166 // And finally the suffix.
167 Res += StringRef(Matches[0].end(), String.end() - Matches[0].end());
168
169 return Res;
170 }