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 "llvm/Support/ErrorHandling.h" 16 #include "llvm/Support/raw_ostream.h" 17 #include "llvm/ADT/SmallVector.h" 18 #include "regex_impl.h" 19 #include <string> 20 using namespace llvm; 21 22 Regex::Regex(const StringRef ®ex, 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 & NoSub) { 29 flags |= REG_NOSUB; 30 sub = false; 31 } else { 32 sub = true; 33 } 34 if (Flags & Newline) 35 flags |= REG_NEWLINE; 36 error = llvm_regcomp(preg, regex.data(), flags|REG_EXTENDED|REG_PEND); 37 } 38 39 bool Regex::isValid(std::string &Error) { 40 if (!error) 41 return true; 42 43 size_t len = llvm_regerror(error, preg, NULL, 0); 44 45 Error.resize(len); 46 llvm_regerror(error, preg, &Error[0], len); 47 return false; 48 } 49 50 Regex::~Regex() { 51 llvm_regfree(preg); 52 delete preg; 53 } 54 55 bool Regex::match(const StringRef &String, SmallVectorImpl<StringRef> *Matches){ 56 unsigned nmatch = Matches ? preg->re_nsub+1 : 0; 57 58 if (Matches) { 59 assert(sub && "Substring matching requested but pattern compiled without"); 60 Matches->clear(); 61 } 62 63 // pmatch needs to have at least one element. 64 SmallVector<llvm_regmatch_t, 8> pm; 65 pm.resize(nmatch > 0 ? nmatch : 1); 66 pm[0].rm_so = 0; 67 pm[0].rm_eo = String.size(); 68 69 int rc = llvm_regexec(preg, String.data(), nmatch, pm.data(), REG_STARTEND); 70 71 if (rc == REG_NOMATCH) 72 return false; 73 if (rc != 0) { 74 // regexec can fail due to invalid pattern or running out of memory. 75 error = rc; 76 return false; 77 } 78 79 // There was a match. 80 81 if (Matches) { // match position requested 82 for (unsigned i = 0; i != nmatch; ++i) { 83 if (pm[i].rm_so == -1) { 84 // this group didn't match 85 Matches->push_back(StringRef()); 86 continue; 87 } 88 assert(pm[i].rm_eo > pm[i].rm_so); 89 Matches->push_back(StringRef(String.data()+pm[i].rm_so, 90 pm[i].rm_eo-pm[i].rm_so)); 91 } 92 } 93 94 return true; 95 } 96