From 07f51f788e1dff2982ff0aae7c2ea3d00e48cc61 Mon Sep 17 00:00:00 2001
From: Chris Lattner <sabre@nondot.org>
Date: Sun, 17 Aug 2008 04:13:37 +0000
Subject: [PATCH] add support for a cout/cerr analog (outs()/errs()) as well as
 a simple adaptor class to give raw output capabilities to something that
 wants to write to an ostream.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54865 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/Support/raw_ostream.h | 29 +++++++++++++++++++++++++++-
 lib/Support/raw_ostream.cpp        | 31 ++++++++++++++++++++++++++++++
 2 files changed, 59 insertions(+), 1 deletion(-)

diff --git a/include/llvm/Support/raw_ostream.h b/include/llvm/Support/raw_ostream.h
index 6d538003fed..34dd052e88c 100644
--- a/include/llvm/Support/raw_ostream.h
+++ b/include/llvm/Support/raw_ostream.h
@@ -1,4 +1,4 @@
-//===--- raw_ostream.h - Raw output stream ---------------------------------===//
+//===--- raw_ostream.h - Raw output stream --------------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
@@ -15,6 +15,7 @@
 #define LLVM_SUPPORT_RAW_OSTREAM_H
 
 #include <string>
+#include <iosfwd>
 
 namespace llvm {
 
@@ -151,6 +152,8 @@ public:
   virtual void flush_impl();
 };
   
+/// raw_stdout_ostream - This is a stream that always prints to stdout.
+///
 class raw_stdout_ostream : public raw_fd_ostream {
   // An out of line virtual method to provide a home for the class vtable.
   virtual void handle();
@@ -158,6 +161,8 @@ public:
   raw_stdout_ostream();
 };
 
+/// raw_stderr_ostream - This is a stream that always prints to stderr.
+///
 class raw_stderr_ostream : public raw_fd_ostream {
   // An out of line virtual method to provide a home for the class vtable.
   virtual void handle();
@@ -165,6 +170,28 @@ public:
   raw_stderr_ostream();
 };
   
+/// outs() - This returns a reference to a raw_ostream for standard output.
+/// Use it like: outs() << "foo" << "bar";
+raw_ostream &outs();
+
+/// errs() - This returns a reference to a raw_ostream for standard error.
+/// Use it like: errs() << "foo" << "bar";
+raw_ostream &errs();
+  
+  
+/// raw_os_ostream - A raw_ostream that writes to an std::ostream.  This is a
+/// simple adaptor class.
+class raw_os_ostream : public raw_ostream {
+  std::ostream &OS;
+public:
+  raw_os_ostream(std::ostream &O) : OS(O) {}
+  
+  /// 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
 
 #endif
diff --git a/lib/Support/raw_ostream.cpp b/lib/Support/raw_ostream.cpp
index a4dc797f01c..96864277170 100644
--- a/lib/Support/raw_ostream.cpp
+++ b/lib/Support/raw_ostream.cpp
@@ -12,6 +12,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Support/raw_ostream.h"
+#include <ostream>
 using namespace llvm;
 
 #if !defined(_MSC_VER)
@@ -62,6 +63,9 @@ void raw_fd_ostream::flush_impl() {
   HandleFlush();
 }
 
+//===----------------------------------------------------------------------===//
+//  raw_stdout/err_ostream
+//===----------------------------------------------------------------------===//
 
 raw_stdout_ostream::raw_stdout_ostream():raw_fd_ostream(STDOUT_FILENO, false) {}
 raw_stderr_ostream::raw_stderr_ostream():raw_fd_ostream(STDERR_FILENO, false) {}
@@ -69,3 +73,30 @@ raw_stderr_ostream::raw_stderr_ostream():raw_fd_ostream(STDERR_FILENO, false) {}
 // An out of line virtual method to provide a home for the class vtable.
 void raw_stdout_ostream::handle() {}
 void raw_stderr_ostream::handle() {}
+
+/// outs() - This returns a reference to a raw_ostream for standard output.
+/// Use it like: outs() << "foo" << "bar";
+raw_ostream &outs() {
+  static raw_stdout_ostream S;
+  return S;
+}
+
+/// errs() - This returns a reference to a raw_ostream for standard error.
+/// Use it like: errs() << "foo" << "bar";
+raw_ostream &errs() {
+  static raw_stderr_ostream S;
+  return S;
+}
+
+//===----------------------------------------------------------------------===//
+//  raw_os_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.
+void raw_os_ostream::flush_impl() {
+  if (OutBufCur-OutBufStart)
+    OS.write(OutBufStart, OutBufCur-OutBufStart);
+  HandleFlush();
+}
-- 
2.34.1