remove support for "NoSub" from regex.  It seems like a minor optimization
and makes the API more annoying.  Add a Regex::getNumMatches() method.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82877 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Support/Regex.cpp b/lib/Support/Regex.cpp
index 285e01f..618ca05 100644
--- a/lib/Support/Regex.cpp
+++ b/lib/Support/Regex.cpp
@@ -25,41 +25,36 @@
   preg->re_endp = regex.end();
   if (Flags & IgnoreCase) 
     flags |= REG_ICASE;
-  if (Flags & NoSub) {
-    flags |= REG_NOSUB;
-    sub = false;
-  } else {
-    sub = true;
-  }
   if (Flags & Newline)
     flags |= REG_NEWLINE;
   error = llvm_regcomp(preg, regex.data(), flags|REG_EXTENDED|REG_PEND);
 }
 
-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;
-}
-
 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;
 
-  if (Matches) {
-    assert(sub && "Substring matching requested but pattern compiled without");
-    Matches->clear();
-  }
-
   // pmatch needs to have at least one element.
   SmallVector<llvm_regmatch_t, 8> pm;
   pm.resize(nmatch > 0 ? nmatch : 1);
@@ -79,6 +74,8 @@
   // 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