1 files changed, 168 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Support/Regex.cpp b/contrib/llvm/lib/Support/Regex.cpp
new file mode 100644
index 000000000000..d293da07d684
--- /dev/null
+++ b/contrib/llvm/lib/Support/Regex.cpp
@@ -0,0 +1,168 @@
+//===-- 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(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(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;
+}
+
+std::string Regex::sub(StringRef Repl, StringRef String,
+                       std::string *Error) {
+  SmallVector<StringRef, 8> Matches;
+
+  // Reset error, if given.
+  if (Error && !Error->empty()) *Error = "";
+
+  // Return the input if there was no match.
+  if (!match(String, &Matches))
+    return String;
+
+  // Otherwise splice in the replacement string, starting with the prefix before
+  // the match.
+  std::string Res(String.begin(), Matches[0].begin());
+
+  // Then the replacement string, honoring possible substitutions.
+  while (!Repl.empty()) {
+    // Skip to the next escape.
+    std::pair<StringRef, StringRef> Split = Repl.split('\\');
+
+    // Add the skipped substring.
+    Res += Split.first;
+
+    // Check for terminimation and trailing backslash.
+    if (Split.second.empty()) {
+      if (Repl.size() != Split.first.size() &&
+          Error && Error->empty())
+        *Error = "replacement string contained trailing backslash";
+      break;
+    }
+
+    // Otherwise update the replacement string and interpret escapes.
+    Repl = Split.second;
+
+    // FIXME: We should have a StringExtras function for mapping C99 escapes.
+    switch (Repl[0]) {
+      // Treat all unrecognized characters as self-quoting.
+    default:
+      Res += Repl[0];
+      Repl = Repl.substr(1);
+      break;
+
+      // Single character escapes.
+    case 't':
+      Res += '\t';
+      Repl = Repl.substr(1);
+      break;
+    case 'n':
+      Res += '\n';
+      Repl = Repl.substr(1);
+      break;
+
+      // Decimal escapes are backreferences.
+    case '0': case '1': case '2': case '3': case '4':
+    case '5': case '6': case '7': case '8': case '9': {
+      // Extract the backreference number.
+      StringRef Ref = Repl.slice(0, Repl.find_first_not_of("0123456789"));
+      Repl = Repl.substr(Ref.size());
+
+      unsigned RefValue;
+      if (!Ref.getAsInteger(10, RefValue) &&
+          RefValue < Matches.size())
+        Res += Matches[RefValue];
+      else if (Error && Error->empty())
+        *Error = "invalid backreference string '" + Ref.str() + "'";
+      break;
+    }
+    }
+  }
+
+  // And finally the suffix.
+  Res += StringRef(Matches[0].end(), String.end() - Matches[0].end());
+
+  return Res;
+}