Bring in a BumpPtrStringSaver from lld and simplify the interface.

StringSaver now always saves to a BumpPtrAllocator.

The only reason for having the virtual saveImpl is so lld can have a
thread safe version.

The reason for the distinct BumpPtrStringSaver class is to avoid the
virtual destructor.

llvm-svn: 239669

2 files changed, 45 insertions, 10 deletions

diff --git a/llvm/include/llvm/Support/CommandLine.h b/llvm/include/llvm/Support/CommandLine.h
index 1ad8a3bfd93..ed809211ea9 100644
--- a/llvm/include/llvm/Support/CommandLine.h
+++ b/llvm/include/llvm/Support/CommandLine.h
@@ -33,6 +33,9 @@
 
 namespace llvm {
 
+class BumpPtrStringSaver;
+class StringSaver;
+
 /// cl Namespace - This namespace contains all of the command line option
 /// processing machinery.  It is intentionally a short name to make qualified
 /// usage concise.
@@ -1676,16 +1679,6 @@ StringMap<Option *> &getRegisteredOptions();
 // Standalone command line processing utilities.
 //
 
-/// \brief Saves strings in the inheritor's stable storage and returns a stable
-/// raw character pointer.
-class StringSaver {
-  virtual void anchor();
-
-public:
-  virtual const char *SaveString(const char *Str) = 0;
-  virtual ~StringSaver(){}; // Pacify -Wnon-virtual-dtor.
-};
-
 /// \brief Tokenizes a command line that can contain escapes and quotes.
 //
 /// The quoting rules match those used by GCC and other tools that use
diff --git a/llvm/include/llvm/Support/StringSaver.h b/llvm/include/llvm/Support/StringSaver.h
new file mode 100644
index 00000000000..f3853ee9157
--- /dev/null
+++ b/llvm/include/llvm/Support/StringSaver.h
@@ -0,0 +1,42 @@
+//===- llvm/Support/StringSaver.h -------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_SUPPORT_STRINGSAVER_H
+#define LLVM_SUPPORT_STRINGSAVER_H
+
+#include "llvm/ADT/StringRef.h"
+#include "llvm/ADT/Twine.h"
+#include "llvm/Support/Allocator.h"
+
+namespace llvm {
+
+/// \brief Saves strings in the inheritor's stable storage and returns a stable
+/// raw character pointer.
+class StringSaver {
+protected:
+  ~StringSaver() {}
+  virtual const char *saveImpl(StringRef S);
+
+public:
+  StringSaver(BumpPtrAllocator &Alloc) : Alloc(Alloc) {}
+  const char *save(const char *S) { return save(StringRef(S)); }
+  const char *save(StringRef S) { return saveImpl(S); }
+  const char *save(const Twine &S) { return save(StringRef(S.str())); }
+  const char *save(std::string &S) { return save(StringRef(S)); }
+
+private:
+  BumpPtrAllocator &Alloc;
+};
+
+class BumpPtrStringSaver final : public StringSaver {
+public:
+  BumpPtrStringSaver(BumpPtrAllocator &Alloc) : StringSaver(Alloc) {}
+};
+}
+#endif