Add raw_stream adaptors that write into an std::string and SmallVector/SmallString.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55265 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Support/raw_ostream.h

@@ -22,6 +22,8 @@
 
 namespace llvm {
   class format_object_base;
+  template <typename T>
+  class SmallVectorImpl;
   
 /// raw_ostream - This class implements an extremely fast bulk output stream
 /// that can *only* output to a stream.  It does not support seeking, reopening,
@@ -192,7 +194,7 @@ raw_ostream &errs();
   
   
 //===----------------------------------------------------------------------===//
-// Bridge Output Streams
+// Output Stream Adaptors
 //===----------------------------------------------------------------------===//
   
 /// raw_os_ostream - A raw_ostream that writes to an std::ostream.  This is a
@@ -208,6 +210,34 @@ public:
   /// buffer to empty.
   virtual void flush_impl();
 };
+
+/// raw_string_ostream - A raw_ostream that writes to an std::string.  This is a
+/// simple adaptor class.
+class raw_string_ostream : public raw_ostream {
+  std::string &OS;
+public:
+  raw_string_ostream(std::string &O) : OS(O) {}
+  ~raw_string_ostream();
+  
+  /// flush_impl - The is the piece of the class that is implemented by
+  /// subclasses.  This outputs the currently buffered data and resets the
+  /// buffer to empty.
+  virtual void flush_impl();
+};
+  
+/// raw_svector_ostream - A raw_ostream that writes to an SmallVector or
+/// SmallString.  This is a simple adaptor class.
+class raw_svector_ostream : public raw_ostream {
+  SmallVectorImpl<char> &OS;
+public:
+  raw_svector_ostream(SmallVectorImpl<char> &O) : OS(O) {}
+  ~raw_svector_ostream();
+  
+  /// flush_impl - The is the piece of the class that is implemented by
+  /// subclasses.  This outputs the currently buffered data and resets the
+  /// buffer to empty.
+  virtual void flush_impl();
+};
   
 } // end llvm namespace
 

lib/Support/raw_ostream.cpp

@@ -268,3 +268,38 @@ void raw_os_ostream::flush_impl() {
     OS.write(OutBufStart, OutBufCur-OutBufStart);
   HandleFlush();
 }
+
+//===----------------------------------------------------------------------===//
+//  raw_string_ostream
+//===----------------------------------------------------------------------===//
+
+raw_string_ostream::~raw_string_ostream() {
+  flush();
+}
+
+/// flush_impl - The is the piece of the class that is implemented by
+/// subclasses.  This outputs the currently buffered data and resets the
+/// buffer to empty.
+void raw_string_ostream::flush_impl() {
+  if (OutBufCur-OutBufStart)
+    OS.append(OutBufStart, OutBufCur-OutBufStart);
+  HandleFlush();
+}
+
+//===----------------------------------------------------------------------===//
+//  raw_svector_ostream
+//===----------------------------------------------------------------------===//
+
+raw_svector_ostream::~raw_svector_ostream() {
+  flush();
+}
+
+/// flush_impl - The is the piece of the class that is implemented by
+/// subclasses.  This outputs the currently buffered data and resets the
+/// buffer to empty.
+void raw_svector_ostream::flush_impl() {
+  if (OutBufCur-OutBufStart)
+    OS.append(OutBufStart, OutBufCur);
+  HandleFlush();
+}
+