Add classof implementations to the raw_ostream classes.

More uses to follow in a another patch.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234460 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/MC/MCLinkerOptimizationHint.h

@@ -140,8 +140,12 @@ public:
       uint64_t current_pos() const override { return Count; }
 
     public:
-      raw_counting_ostream() : Count(0) {}
+      raw_counting_ostream() : raw_ostream(SK_COUNTING), Count(0) {}
       ~raw_counting_ostream() { flush(); }
+
+      static bool classof(const raw_ostream *OS) {
+        return OS->getKind() == SK_COUNTING;
+      }
     };
 
     raw_counting_ostream OutStream;

include/llvm/Support/FormattedStream.h

@@ -84,15 +84,21 @@ public:
   /// so it doesn't want another layer of buffering to be happening
   /// underneath it.
   ///
-  formatted_raw_ostream(raw_ostream &Stream, bool Delete = false) 
-    : raw_ostream(), TheStream(nullptr), DeleteStream(false), Position(0, 0) {
+  formatted_raw_ostream(raw_ostream &Stream, bool Delete = false)
+      : raw_ostream(SK_FORMATTED), TheStream(nullptr), DeleteStream(false),
+        Position(0, 0) {
     setStream(Stream, Delete);
   }
   explicit formatted_raw_ostream()
-    : raw_ostream(), TheStream(nullptr), DeleteStream(false), Position(0, 0) {
+      : raw_ostream(SK_FORMATTED), TheStream(nullptr), DeleteStream(false),
+        Position(0, 0) {
     Scanned = nullptr;
   }
 
+  static bool classof(const raw_ostream *OS) {
+    return OS->getKind() == SK_FORMATTED;
+  }
+
   ~formatted_raw_ostream() {
     flush();
     releaseStream();

include/llvm/Support/circular_raw_ostream.h

@@ -107,14 +107,10 @@ namespace llvm
     /// management of it, etc.
     ///
     circular_raw_ostream(raw_ostream &Stream, const char *Header,
-                         size_t BuffSize = 0, bool Owns = REFERENCE_ONLY) 
-        : raw_ostream(/*unbuffered*/true),
-            TheStream(nullptr),
-            OwnsStream(Owns),
-            BufferSize(BuffSize),
-            BufferArray(nullptr),
-            Filled(false),
-            Banner(Header) {
+                         size_t BuffSize = 0, bool Owns = REFERENCE_ONLY)
+        : raw_ostream(SK_CIRCULAR, /*unbuffered*/ true), TheStream(nullptr),
+          OwnsStream(Owns), BufferSize(BuffSize), BufferArray(nullptr),
+          Filled(false), Banner(Header) {
       if (BufferSize != 0)
         BufferArray = new char[BufferSize];
       Cur = BufferArray;
@@ -144,6 +140,10 @@ namespace llvm
     ///
     void flushBufferWithBanner();
 
+    static bool classof(const raw_ostream *OS) {
+      return OS->getKind() == SK_CIRCULAR;
+    }
+
   private:
     /// releaseStream - Delete the held stream if needed. Otherwise,
     /// transfer the buffer settings from this circular_raw_ostream

include/llvm/Support/raw_os_ostream.h

@@ -33,8 +33,11 @@ class raw_os_ostream : public raw_ostream {
   uint64_t current_pos() const override;
 
 public:
-  raw_os_ostream(std::ostream &O) : OS(O) {}
+  raw_os_ostream(std::ostream &O) : raw_ostream(SK_STD_OS), OS(O) {}
   ~raw_os_ostream();
+  static bool classof(const raw_ostream *OS) {
+    return OS->getKind() == SK_STD_OS;
+  }
 };
 
 } // end llvm namespace

include/llvm/Support/raw_ostream.h

@@ -16,6 +16,7 @@
 
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/StringRef.h"
+#include "llvm/Support/Casting.h"
 #include "llvm/Support/DataTypes.h"
 #include <system_error>
 
@@ -67,6 +68,17 @@ private:
   } BufferMode;
 
 public:
+  enum StreamKind {
+    SK_FD,
+    SK_STRING,
+    SK_SVECTOR,
+    SK_NULL,
+    SK_STD_OS,
+    SK_CIRCULAR,
+    SK_FORMATTED,
+    SK_COUNTING
+  };
+
   // color order matches ANSI escape sequence, don't change
   enum Colors {
     BLACK=0,
@@ -80,8 +92,8 @@ public:
     SAVEDCOLOR
   };
 
-  explicit raw_ostream(bool unbuffered=false)
-    : BufferMode(unbuffered ? Unbuffered : InternalBuffer) {
+  explicit raw_ostream(StreamKind Kind, bool unbuffered = false)
+      : BufferMode(unbuffered ? Unbuffered : InternalBuffer), Kind(Kind) {
     // Start out ready to flush.
     OutBufStart = OutBufEnd = OutBufCur = nullptr;
   }
@@ -259,7 +271,10 @@ public:
   // Subclass Interface
   //===--------------------------------------------------------------------===//
 
+  StreamKind getKind() const { return Kind; }
+
 private:
+  StreamKind Kind;
   /// The is the piece of the class that is implemented by subclasses.  This
   /// writes the \p Size bytes starting at
   /// \p Ptr to the underlying stream.
@@ -364,6 +379,8 @@ public:
   /// this closes the file when the stream is destroyed.
   raw_fd_ostream(int fd, bool shouldClose, bool unbuffered=false);
 
+  static bool classof(const raw_ostream *OS) { return OS->getKind() == SK_FD; }
+
   ~raw_fd_ostream();
 
   /// Manually flush the stream and close the file. Note that this does not call
@@ -443,9 +460,13 @@ class raw_string_ostream : public raw_ostream {
   /// currently in the buffer.
   uint64_t current_pos() const override { return OS.size(); }
 public:
-  explicit raw_string_ostream(std::string &O) : OS(O) {}
+  explicit raw_string_ostream(std::string &O) : raw_ostream(SK_STRING), OS(O) {}
   ~raw_string_ostream();
 
+  static bool classof(const raw_ostream *OS) {
+    return OS->getKind() == SK_STRING;
+  }
+
   /// Flushes the stream contents to the target string and returns  the string's
   /// reference.
   std::string& str() {
@@ -473,6 +494,10 @@ public:
   explicit raw_svector_ostream(SmallVectorImpl<char> &O);
   ~raw_svector_ostream();
 
+  static bool classof(const raw_ostream *OS) {
+    return OS->getKind() == SK_SVECTOR;
+  }
+
   /// This is called when the SmallVector we're appending to is changed outside
   /// of the raw_svector_ostream's control.  It is only safe to do this if the
   /// raw_svector_ostream has previously been flushed.
@@ -493,8 +518,11 @@ class raw_null_ostream : public raw_ostream {
   uint64_t current_pos() const override;
 
 public:
-  explicit raw_null_ostream() {}
+  explicit raw_null_ostream() : raw_ostream(SK_NULL) {}
   ~raw_null_ostream();
+  static bool classof(const raw_ostream *OS) {
+    return OS->getKind() == SK_NULL;
+  }
 };
 
 } // end llvm namespace

lib/Support/Debug.cpp

@@ -114,9 +114,8 @@ static void debug_user_sig_handler(void *Cookie) {
   // know that debug mode is enabled and dbgs() really is a
   // circular_raw_ostream.  If NDEBUG is defined, then dbgs() ==
   // errs() but this will never be invoked.
-  llvm::circular_raw_ostream *dbgout =
-    static_cast<llvm::circular_raw_ostream *>(&llvm::dbgs());
-  dbgout->flushBufferWithBanner();
+  llvm::circular_raw_ostream &dbgout = cast<circular_raw_ostream>(llvm::dbgs());
+  dbgout.flushBufferWithBanner();
 }
 
 /// dbgs - Return a circular-buffered debug stream.

lib/Support/raw_ostream.cpp

@@ -489,7 +489,7 @@ void format_object_base::home() {
 
 raw_fd_ostream::raw_fd_ostream(StringRef Filename, std::error_code &EC,
                                sys::fs::OpenFlags Flags)
-    : Error(false), UseAtomicWrites(false), pos(0) {
+    : raw_ostream(SK_FD), Error(false), UseAtomicWrites(false), pos(0) {
   EC = std::error_code();
   // Handle "-" as stdout. Note that when we do this, we consider ourself
   // the owner of stdout. This means that we can do things like close the
@@ -519,8 +519,8 @@ raw_fd_ostream::raw_fd_ostream(StringRef Filename, std::error_code &EC,
 /// raw_fd_ostream ctor - FD is the file descriptor that this writes to.  If
 /// ShouldClose is true, this closes the file when the stream is destroyed.
 raw_fd_ostream::raw_fd_ostream(int fd, bool shouldClose, bool unbuffered)
-  : raw_ostream(unbuffered), FD(fd),
-    ShouldClose(shouldClose), Error(false), UseAtomicWrites(false) {
+    : raw_ostream(SK_FD, unbuffered), FD(fd), ShouldClose(shouldClose),
+      Error(false), UseAtomicWrites(false) {
 #ifdef O_BINARY
   // Setting STDOUT to binary mode is necessary in Win32
   // to avoid undesirable linefeed conversion.
@@ -749,7 +749,8 @@ void raw_string_ostream::write_impl(const char *Ptr, size_t Size) {
 // capacity. This allows raw_ostream to write directly into the correct place,
 // and we only need to set the vector size when the data is flushed.
 
-raw_svector_ostream::raw_svector_ostream(SmallVectorImpl<char> &O) : OS(O) {
+raw_svector_ostream::raw_svector_ostream(SmallVectorImpl<char> &O)
+    : raw_ostream(SK_SVECTOR), OS(O) {
   // Set up the initial external buffer. We make sure that the buffer has at
   // least 128 bytes free; raw_ostream itself only requires 64, but we want to
   // make sure that we don't grow the buffer unnecessarily on destruction (when