1 files changed, 97 insertions, 0 deletions
diff --git a/lib/Demangle/StringView.h b/lib/Demangle/StringView.h
new file mode 100644
index 000000000000..3416db2c2867
--- /dev/null
+++ b/lib/Demangle/StringView.h
@@ -0,0 +1,97 @@
+//===--- StringView.h -------------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//
+// This file contains a limited version of LLVM's StringView class.  It is
+// copied here so that LLVMDemangle need not take a dependency on LLVMSupport.
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_DEMANGLE_STRINGVIEW_H
+#define LLVM_DEMANGLE_STRINGVIEW_H
+
+#include <algorithm>
+#include <cassert>
+#include <cstring>
+
+class StringView {
+  const char *First;
+  const char *Last;
+
+public:
+  template <size_t N>
+  StringView(const char (&Str)[N]) : First(Str), Last(Str + N - 1) {}
+  StringView(const char *First_, const char *Last_)
+      : First(First_), Last(Last_) {}
+  StringView(const char *First_, size_t Len)
+      : First(First_), Last(First_ + Len) {}
+  StringView(const char *Str) : First(Str), Last(Str + std::strlen(Str)) {}
+  StringView() : First(nullptr), Last(nullptr) {}
+
+  StringView substr(size_t From) const {
+    return StringView(begin() + From, size() - From);
+  }
+
+  StringView substr(size_t From, size_t To) const {
+    if (To >= size())
+      To = size() - 1;
+    if (From >= size())
+      From = size() - 1;
+    return StringView(First + From, First + To);
+  }
+
+  StringView dropFront(size_t N = 1) const {
+    if (N >= size())
+      N = size();
+    return StringView(First + N, Last);
+  }
+
+  char front() const {
+    assert(!empty());
+    return *begin();
+  }
+
+  char popFront() {
+    assert(!empty());
+    return *First++;
+  }
+
+  bool consumeFront(char C) {
+    if (!startsWith(C))
+      return false;
+    *this = dropFront(1);
+    return true;
+  }
+
+  bool consumeFront(StringView S) {
+    if (!startsWith(S))
+      return false;
+    *this = dropFront(S.size());
+    return true;
+  }
+
+  bool startsWith(char C) const { return !empty() && *begin() == C; }
+
+  bool startsWith(StringView Str) const {
+    if (Str.size() > size())
+      return false;
+    return std::equal(Str.begin(), Str.end(), begin());
+  }
+
+  const char &operator[](size_t Idx) const { return *(begin() + Idx); }
+
+  const char *begin() const { return First; }
+  const char *end() const { return Last; }
+  size_t size() const { return static_cast<size_t>(Last - First); }
+  bool empty() const { return First == Last; }
+};
+
+inline bool operator==(const StringView &LHS, const StringView &RHS) {
+  return LHS.size() == RHS.size() &&
+         std::equal(LHS.begin(), LHS.end(), RHS.begin());
+}
+
+#endif