1 files changed, 92 insertions, 0 deletions
diff --git a/lib/Support/Regex.cpp b/lib/Support/Regex.cpp
new file mode 100644
index 000000000000..618ca0524a04
--- /dev/null
+++ b/lib/Support/Regex.cpp
@@ -0,0 +1,92 @@
+//===-- Regex.cpp - Regular Expression matcher implementation -------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements a POSIX regular expression matcher.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Support/Regex.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/ADT/SmallVector.h"
+#include "regex_impl.h"
+#include <string>
+using namespace llvm;
+
+Regex::Regex(const StringRef &regex, unsigned Flags) {
+  unsigned flags = 0;
+  preg = new llvm_regex();
+  preg->re_endp = regex.end();
+  if (Flags & IgnoreCase) 
+    flags |= REG_ICASE;
+  if (Flags & Newline)
+    flags |= REG_NEWLINE;
+  error = llvm_regcomp(preg, regex.data(), flags|REG_EXTENDED|REG_PEND);
+}
+
+Regex::~Regex() {
+  llvm_regfree(preg);
+  delete preg;
+}
+
+bool Regex::isValid(std::string &Error) {
+  if (!error)
+    return true;
+  
+  size_t len = llvm_regerror(error, preg, NULL, 0);
+  
+  Error.resize(len);
+  llvm_regerror(error, preg, &Error[0], len);
+  return false;
+}
+
+/// getNumMatches - In a valid regex, return the number of parenthesized
+/// matches it contains.
+unsigned Regex::getNumMatches() const {
+  return preg->re_nsub;
+}
+
+bool Regex::match(const StringRef &String, SmallVectorImpl<StringRef> *Matches){
+  unsigned nmatch = Matches ? preg->re_nsub+1 : 0;
+
+  // pmatch needs to have at least one element.
+  SmallVector<llvm_regmatch_t, 8> pm;
+  pm.resize(nmatch > 0 ? nmatch : 1);
+  pm[0].rm_so = 0;
+  pm[0].rm_eo = String.size();
+
+  int rc = llvm_regexec(preg, String.data(), nmatch, pm.data(), REG_STARTEND);
+
+  if (rc == REG_NOMATCH)
+    return false;
+  if (rc != 0) {
+    // regexec can fail due to invalid pattern or running out of memory.
+    error = rc;
+    return false;
+  }
+
+  // There was a match.
+
+  if (Matches) { // match position requested
+    Matches->clear();
+    
+    for (unsigned i = 0; i != nmatch; ++i) {
+      if (pm[i].rm_so == -1) {
+        // this group didn't match
+        Matches->push_back(StringRef());
+        continue;
+      }
+      assert(pm[i].rm_eo > pm[i].rm_so);
+      Matches->push_back(StringRef(String.data()+pm[i].rm_so,
+                                   pm[i].rm_eo-pm[i].rm_so));
+    }
+  }
+
+  return true;
+}