Import llvm::SmallString and dependencies.

Update StringRef and StringExtras with SmallVector functions.

src/llvm/SmallVector.cpp

@@ -0,0 +1,41 @@
+//===- llvm/ADT/SmallVector.cpp - 'Normally small' vectors ----------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the SmallVector class.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/SmallVector.h"
+using namespace llvm;
+
+/// grow_pod - This is an implementation of the grow() method which only works
+/// on POD-like datatypes and is out of line to reduce code duplication.
+void SmallVectorBase::grow_pod(void *FirstEl, size_t MinSizeInBytes,
+                               size_t TSize) {
+  size_t CurSizeBytes = size_in_bytes();
+  size_t NewCapacityInBytes = 2 * capacity_in_bytes() + TSize; // Always grow.
+  if (NewCapacityInBytes < MinSizeInBytes)
+    NewCapacityInBytes = MinSizeInBytes;
+
+  void *NewElts;
+  if (BeginX == FirstEl) {
+    NewElts = malloc(NewCapacityInBytes);
+
+    // Copy the elements over.  No need to run dtors on PODs.
+    memcpy(NewElts, this->BeginX, CurSizeBytes);
+  } else {
+    // If this wasn't grown from the inline copy, grow the allocated space.
+    NewElts = realloc(this->BeginX, NewCapacityInBytes);
+  }
+  assert(NewElts && "Out of memory");
+
+  this->EndX = (char*)NewElts+CurSizeBytes;
+  this->BeginX = NewElts;
+  this->CapacityX = (char*)this->BeginX + NewCapacityInBytes;
+}

src/llvm/StringExtras.cpp

@@ -12,6 +12,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/StringExtras.h"
+#include "llvm/SmallVector.h"
 using namespace llvm;
 
 /// StrInStrNoCase - Portable version of strcasestr.  Locates the first
@@ -43,3 +44,15 @@ std::pair<StringRef, StringRef> llvm::getToken(StringRef Source,
 
   return std::make_pair(Source.slice(Start, End), Source.substr(End));
 }
+
+/// SplitString - Split up the specified string according to the specified
+/// delimiters, appending the result fragments to the output list.
+void llvm::SplitString(StringRef Source,
+                       SmallVectorImpl<StringRef> &OutFragments,
+                       StringRef Delimiters) {
+  std::pair<StringRef, StringRef> S = getToken(Source, Delimiters);
+  while (!S.first.empty()) {
+    OutFragments.push_back(S.first);
+    S = getToken(S.second, Delimiters);
+  }
+}

src/llvm/StringRef.cpp

@@ -8,6 +8,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/StringRef.h"
+#include "llvm/SmallVector.h"
 #include <bitset>
 #include <climits>
 
@@ -261,6 +262,27 @@ StringRef::size_type StringRef::find_last_not_of(StringRef Chars,
   return npos;
 }
 
+void StringRef::split(SmallVectorImpl<StringRef> &A,
+                      StringRef Separators, int MaxSplit,
+                      bool KeepEmpty) const {
+  StringRef rest = *this;
+
+  // rest.data() is used to distinguish cases like "a," that splits into
+  // "a" + "" and "a" that splits into "a" + 0.
+  for (int splits = 0;
+       rest.data() != nullptr && (MaxSplit < 0 || splits < MaxSplit);
+       ++splits) {
+    std::pair<StringRef, StringRef> p = rest.split(Separators);
+
+    if (KeepEmpty || p.first.size() != 0)
+      A.push_back(p.first);
+    rest = p.second;
+  }
+  // If we have a tail left, add it.
+  if (rest.data() != nullptr && (rest.size() != 0 || KeepEmpty))
+    A.push_back(rest);
+}
+
 //===----------------------------------------------------------------------===//
 // Helpful Algorithms
 //===----------------------------------------------------------------------===//