X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FSupport%2Fraw_ostream.cpp;h=ad47cb6cf5e917f697d78d8850f388ebd3479780;hb=5fe89d0126ec215ac2a09884bfbd4dd7bf8e7d2f;hp=0595fe47e12affae25a7dbeb565c725d68f07be3;hpb=d3a974fc20ba3451d0ba331e44c09cd7d7ca7fcc;p=oota-llvm.git

diff --git a/lib/Support/raw_ostream.cpp b/lib/Support/raw_ostream.cpp
index 0595fe47e12..ad47cb6cf5e 100644
--- a/lib/Support/raw_ostream.cpp
+++ b/lib/Support/raw_ostream.cpp
@@ -19,7 +19,11 @@
 #include "llvm/Config/config.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/ErrorHandling.h"
-#include <ostream>
+#include "llvm/ADT/STLExtras.h"
+#include <cctype>
+#include <cerrno>
+#include <sys/stat.h>
+#include <sys/types.h>
 
 #if defined(HAVE_UNISTD_H)
 # include <unistd.h>
@@ -44,19 +48,68 @@
 
 using namespace llvm;
 
+raw_ostream::~raw_ostream() {
+  // raw_ostream's subclasses should take care to flush the buffer
+  // in their destructors.
+  assert(OutBufCur == OutBufStart &&
+         "raw_ostream destructor called with non-empty buffer!");
+
+  if (BufferMode == InternalBuffer)
+    delete [] OutBufStart;
+
+  // If there are any pending errors, report them now. Clients wishing
+  // to avoid report_fatal_error calls should check for errors with
+  // has_error() and clear the error flag with clear_error() before
+  // destructing raw_ostream objects which may have errors.
+  if (Error)
+    report_fatal_error("IO failure on output stream.");
+}
 
 // An out of line virtual method to provide a home for the class vtable.
 void raw_ostream::handle() {}
 
+size_t raw_ostream::preferred_buffer_size() const {
+  // BUFSIZ is intended to be a reasonable default.
+  return BUFSIZ;
+}
+
+void raw_ostream::SetBuffered() {
+  // Ask the subclass to determine an appropriate buffer size.
+  if (size_t Size = preferred_buffer_size())
+    SetBufferSize(Size);
+  else
+    // It may return 0, meaning this stream should be unbuffered.
+    SetUnbuffered();
+}
+
+void raw_ostream::SetBufferAndMode(char *BufferStart, size_t Size,
+                                    BufferKind Mode) {
+  assert(((Mode == Unbuffered && BufferStart == 0 && Size == 0) ||
+          (Mode != Unbuffered && BufferStart && Size)) &&
+         "stream must be unbuffered or have at least one byte");
+  // Make sure the current buffer is free of content (we can't flush here; the
+  // child buffer management logic will be in write_impl).
+  assert(GetNumBytesInBuffer() == 0 && "Current buffer is non-empty!");
+
+  if (BufferMode == InternalBuffer)
+    delete [] OutBufStart;
+  OutBufStart = BufferStart;
+  OutBufEnd = OutBufStart+Size;
+  OutBufCur = OutBufStart;
+  BufferMode = Mode;
+
+  assert(OutBufStart <= OutBufEnd && "Invalid size!");
+}
+
 raw_ostream &raw_ostream::operator<<(unsigned long N) {
   // Zero is a special case.
   if (N == 0)
     return *this << '0';
-  
+
   char NumberBuffer[20];
   char *EndPtr = NumberBuffer+sizeof(NumberBuffer);
   char *CurPtr = EndPtr;
-  
+
   while (N) {
     *--CurPtr = '0' + char(N % 10);
     N /= 10;
@@ -69,19 +122,19 @@ raw_ostream &raw_ostream::operator<<(long N) {
     *this << '-';
     N = -N;
   }
-  
+
   return this->operator<<(static_cast<unsigned long>(N));
 }
 
 raw_ostream &raw_ostream::operator<<(unsigned long long N) {
-  // Zero is a special case.
-  if (N == 0)
-    return *this << '0';
-  
+  // Output using 32-bit div/mod when possible.
+  if (N == static_cast<unsigned long>(N))
+    return this->operator<<(static_cast<unsigned long>(N));
+
   char NumberBuffer[20];
   char *EndPtr = NumberBuffer+sizeof(NumberBuffer);
   char *CurPtr = EndPtr;
-  
+
   while (N) {
     *--CurPtr = '0' + char(N % 10);
     N /= 10;
@@ -94,14 +147,11 @@ raw_ostream &raw_ostream::operator<<(long long N) {
     *this << '-';
     N = -N;
   }
-  
+
   return this->operator<<(static_cast<unsigned long long>(N));
 }
 
-raw_ostream &raw_ostream::operator<<(const void *P) {
-  uintptr_t N = (uintptr_t) P;
-  *this << '0' << 'x';
-  
+raw_ostream &raw_ostream::write_hex(unsigned long long N) {
   // Zero is a special case.
   if (N == 0)
     return *this << '0';
@@ -111,7 +161,7 @@ raw_ostream &raw_ostream::operator<<(const void *P) {
   char *CurPtr = EndPtr;
 
   while (N) {
-    unsigned x = N % 16;
+    uintptr_t x = N % 16;
     *--CurPtr = (x < 10 ? '0' + x : 'a' + x - 10);
     N /= 16;
   }
@@ -119,44 +169,111 @@ raw_ostream &raw_ostream::operator<<(const void *P) {
   return write(CurPtr, EndPtr-CurPtr);
 }
 
+raw_ostream &raw_ostream::write_escaped(StringRef Str) {
+  for (unsigned i = 0, e = Str.size(); i != e; ++i) {
+    unsigned char c = Str[i];
+
+    switch (c) {
+    case '\\':
+      *this << '\\' << '\\';
+      break;
+    case '\t':
+      *this << '\\' << 't';
+      break;
+    case '\n':
+      *this << '\\' << 'n';
+      break;
+    case '"':
+      *this << '\\' << '"';
+      break;
+    default:
+      if (std::isprint(c)) {
+        *this << c;
+        break;
+      }
+
+      // Always expand to a 3-character octal escape.
+      *this << '\\';
+      *this << char('0' + ((c >> 6) & 7));
+      *this << char('0' + ((c >> 3) & 7));
+      *this << char('0' + ((c >> 0) & 7));
+    }
+  }
+
+  return *this;
+}
+
+raw_ostream &raw_ostream::operator<<(const void *P) {
+  *this << '0' << 'x';
+
+  return write_hex((uintptr_t) P);
+}
+
+raw_ostream &raw_ostream::operator<<(double N) {
+  return this->operator<<(format("%e", N));
+}
+
+
+
 void raw_ostream::flush_nonempty() {
   assert(OutBufCur > OutBufStart && "Invalid call to flush_nonempty.");
-  write_impl(OutBufStart, OutBufCur - OutBufStart);
-  OutBufCur = OutBufStart;    
+  size_t Length = OutBufCur - OutBufStart;
+  OutBufCur = OutBufStart;
+  write_impl(OutBufStart, Length);
 }
 
 raw_ostream &raw_ostream::write(unsigned char C) {
   // Group exceptional cases into a single branch.
-  if (OutBufCur >= OutBufEnd) {
-    if (Unbuffered) {
-      write_impl(reinterpret_cast<char*>(&C), 1);
-      return *this;
+  if (BUILTIN_EXPECT(OutBufCur >= OutBufEnd, false)) {
+    if (BUILTIN_EXPECT(!OutBufStart, false)) {
+      if (BufferMode == Unbuffered) {
+        write_impl(reinterpret_cast<char*>(&C), 1);
+        return *this;
+      }
+      // Set up a buffer and start over.
+      SetBuffered();
+      return write(C);
     }
-    
-    if (!OutBufStart)
-      SetBufferSize();
-    else
-      flush_nonempty();
+
+    flush_nonempty();
   }
 
   *OutBufCur++ = C;
   return *this;
 }
 
-raw_ostream &raw_ostream::write(const char *Ptr, unsigned Size) {
+raw_ostream &raw_ostream::write(const char *Ptr, size_t Size) {
   // Group exceptional cases into a single branch.
   if (BUILTIN_EXPECT(OutBufCur+Size > OutBufEnd, false)) {
-    if (Unbuffered) {
-      write_impl(Ptr, Size);
-      return *this;
+    if (BUILTIN_EXPECT(!OutBufStart, false)) {
+      if (BufferMode == Unbuffered) {
+        write_impl(Ptr, Size);
+        return *this;
+      }
+      // Set up a buffer and start over.
+      SetBuffered();
+      return write(Ptr, Size);
     }
-    
-    if (!OutBufStart)
-      SetBufferSize();
-    else
+
+    // Write out the data in buffer-sized blocks until the remainder
+    // fits within the buffer.
+    do {
+      size_t NumBytes = OutBufEnd - OutBufCur;
+      copy_to_buffer(Ptr, NumBytes);
       flush_nonempty();
+      Ptr += NumBytes;
+      Size -= NumBytes;
+    } while (OutBufCur+Size > OutBufEnd);
   }
-  
+
+  copy_to_buffer(Ptr, Size);
+
+  return *this;
+}
+
+void raw_ostream::copy_to_buffer(const char *Ptr, size_t Size) {
+  assert(Size <= size_t(OutBufEnd - OutBufCur) && "Buffer overrun!");
+
   // Handle short strings specially, memcpy isn't very good at very short
   // strings.
   switch (Size) {
@@ -166,70 +283,74 @@ raw_ostream &raw_ostream::write(const char *Ptr, unsigned Size) {
   case 1: OutBufCur[0] = Ptr[0]; // FALL THROUGH
   case 0: break;
   default:
-    // Normally the string to emit is shorter than the buffer.
-    if (Size <= unsigned(OutBufEnd-OutBufCur)) {
-      memcpy(OutBufCur, Ptr, Size);
-      break;
-    } 
-
-    // Otherwise we are emitting a string larger than our buffer. We
-    // know we already flushed, so just write it out directly.
-    write_impl(Ptr, Size);
-    Size = 0;
+    memcpy(OutBufCur, Ptr, Size);
     break;
   }
-  OutBufCur += Size;
 
-  return *this;
+  OutBufCur += Size;
 }
 
 // Formatted output.
 raw_ostream &raw_ostream::operator<<(const format_object_base &Fmt) {
   // If we have more than a few bytes left in our output buffer, try
   // formatting directly onto its end.
-  //
-  // FIXME: This test is a bit silly, since if we don't have enough
-  // space in the buffer we will have to flush the formatted output
-  // anyway. We should just flush upfront in such cases, and use the
-  // whole buffer as our scratch pad. Note, however, that this case is
-  // also necessary for correctness on unbuffered streams.
-  unsigned NextBufferSize = 127;
-  if (OutBufEnd-OutBufCur > 3) {
-    unsigned BufferBytesLeft = OutBufEnd-OutBufCur;
-    unsigned BytesUsed = Fmt.print(OutBufCur, BufferBytesLeft);
-    
+  size_t NextBufferSize = 127;
+  size_t BufferBytesLeft = OutBufEnd - OutBufCur;
+  if (BufferBytesLeft > 3) {
+    size_t BytesUsed = Fmt.print(OutBufCur, BufferBytesLeft);
+
     // Common case is that we have plenty of space.
-    if (BytesUsed < BufferBytesLeft) {
+    if (BytesUsed <= BufferBytesLeft) {
       OutBufCur += BytesUsed;
       return *this;
     }
-    
+
     // Otherwise, we overflowed and the return value tells us the size to try
     // again with.
     NextBufferSize = BytesUsed;
   }
-  
+
   // If we got here, we didn't have enough space in the output buffer for the
   // string.  Try printing into a SmallVector that is resized to have enough
   // space.  Iterate until we win.
   SmallVector<char, 128> V;
-  
+
   while (1) {
     V.resize(NextBufferSize);
-    
+
     // Try formatting into the SmallVector.
-    unsigned BytesUsed = Fmt.print(&V[0], NextBufferSize);
-    
+    size_t BytesUsed = Fmt.print(V.data(), NextBufferSize);
+
     // If BytesUsed fit into the vector, we win.
     if (BytesUsed <= NextBufferSize)
-      return write(&V[0], BytesUsed);
-    
+      return write(V.data(), BytesUsed);
+
     // Otherwise, try again with a new size.
     assert(BytesUsed > NextBufferSize && "Didn't grow buffer!?");
     NextBufferSize = BytesUsed;
   }
 }
 
+/// indent - Insert 'NumSpaces' spaces.
+raw_ostream &raw_ostream::indent(unsigned NumSpaces) {
+  static const char Spaces[] = "                                "
+                               "                                "
+                               "                ";
+
+  // Usually the indentation is small, handle it with a fastpath.
+  if (NumSpaces < array_lengthof(Spaces))
+    return write(Spaces, NumSpaces);
+
+  while (NumSpaces) {
+    unsigned NumToWrite = std::min(NumSpaces,
+                                   (unsigned)array_lengthof(Spaces)-1);
+    write(Spaces, NumToWrite);
+    NumSpaces -= NumToWrite;
+  }
+  return *this;
+}
+
+
 //===----------------------------------------------------------------------===//
 //  Formatted Output
 //===----------------------------------------------------------------------===//
@@ -246,8 +367,13 @@ void format_object_base::home() {
 /// occurs, information about the error is put into ErrorInfo, and the
 /// stream should be immediately destroyed; the string will be empty
 /// if no error occurred.
-raw_fd_ostream::raw_fd_ostream(const char *Filename, bool Binary,
-                               std::string &ErrorInfo) : pos(0) {
+raw_fd_ostream::raw_fd_ostream(const char *Filename, std::string &ErrorInfo,
+                               unsigned Flags) : pos(0) {
+  assert(Filename != 0 && "Filename is null");
+  // Verify that we don't have both "append" and "excl".
+  assert((!(Flags & F_Excl) || !(Flags & F_Append)) &&
+         "Cannot specify both 'excl' and 'append' file creation flags!");
+
   ErrorInfo.clear();
 
   // Handle "-" as stdout.
@@ -255,18 +381,26 @@ raw_fd_ostream::raw_fd_ostream(const char *Filename, bool Binary,
     FD = STDOUT_FILENO;
     // If user requested binary then put stdout into binary mode if
     // possible.
-    if (Binary)
+    if (Flags & F_Binary)
       sys::Program::ChangeStdoutToBinary();
     ShouldClose = false;
     return;
   }
-  
-  int Flags = O_WRONLY|O_CREAT|O_TRUNC;
+
+  int OpenFlags = O_WRONLY|O_CREAT;
 #ifdef O_BINARY
-  if (Binary)
-    Flags |= O_BINARY;
+  if (Flags & F_Binary)
+    OpenFlags |= O_BINARY;
 #endif
-  FD = open(Filename, Flags, 0664);
+
+  if (Flags & F_Append)
+    OpenFlags |= O_APPEND;
+  else
+    OpenFlags |= O_TRUNC;
+  if (Flags & F_Excl)
+    OpenFlags |= O_EXCL;
+
+  FD = open(Filename, OpenFlags, 0664);
   if (FD < 0) {
     ErrorInfo = "Error opening output file '" + std::string(Filename) + "'";
     ShouldClose = false;
@@ -276,27 +410,50 @@ raw_fd_ostream::raw_fd_ostream(const char *Filename, bool Binary,
 }
 
 raw_fd_ostream::~raw_fd_ostream() {
-  if (FD >= 0) {
-    flush();
-    if (ShouldClose)
-      if (::close(FD) != 0)
-        llvm_report_error("IO failure closing output stream.");
-  }
+  if (FD < 0) return;
+  flush();
+  if (ShouldClose)
+    if (::close(FD) != 0)
+      error_detected();
 }
 
-void raw_fd_ostream::write_impl(const char *Ptr, unsigned Size) {
-  assert (FD >= 0 && "File already closed.");
+
+void raw_fd_ostream::write_impl(const char *Ptr, size_t Size) {
+  assert(FD >= 0 && "File already closed.");
   pos += Size;
-  if (::write(FD, Ptr, Size) != (ssize_t) Size)
-    llvm_report_error("IO failure writing to output stream.");
+  ssize_t ret;
+
+  do {
+    ret = ::write(FD, Ptr, Size);
+
+    if (ret < 0) {
+      // If it's a recoverable error, swallow it and retry the write.
+      // EAGAIN and EWOULDBLOCK are not unambiguously recoverable, but
+      // some programs, such as bjam, assume that their child processes
+      // will treat them as if they are. If you don't want this code to
+      // spin, don't use O_NONBLOCK file descriptors with raw_ostream.
+      if (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK)
+        continue;
+
+      // Otherwise it's a non-recoverable error. Note it and quit.
+      error_detected();
+      break;
+    }
+
+    // The write may have written some or all of the data. Update the
+    // size and buffer pointer to reflect the remainder that needs
+    // to be written. If there are no bytes left, we're done.
+    Ptr += ret;
+    Size -= ret;
+  } while (Size > 0);
 }
 
 void raw_fd_ostream::close() {
-  assert (ShouldClose);
+  assert(ShouldClose);
   ShouldClose = false;
   flush();
   if (::close(FD) != 0)
-    llvm_report_error("IO failure closing output stream.");
+    error_detected();
   FD = -1;
 }
 
@@ -304,8 +461,27 @@ uint64_t raw_fd_ostream::seek(uint64_t off) {
   flush();
   pos = ::lseek(FD, off, SEEK_SET);
   if (pos != off)
-    llvm_report_error("IO failure seeking on output stream.");
-  return pos;  
+    error_detected();
+  return pos;
+}
+
+size_t raw_fd_ostream::preferred_buffer_size() const {
+#if !defined(_MSC_VER) && !defined(__MINGW32__) && !defined(_MINIX)
+  // Windows and Minix have no st_blksize.
+  assert(FD >= 0 && "File not yet open!");
+  struct stat statbuf;
+  if (fstat(FD, &statbuf) != 0)
+    return 0;
+
+  // If this is a terminal, don't use buffering. Line buffering
+  // would be a more traditional thing to do, but it's not worth
+  // the complexity.
+  if (S_ISCHR(statbuf.st_mode) && isatty(FD))
+    return 0;
+  // Return the preferred block size.
+  return statbuf.st_blksize;
+#endif
+  return raw_ostream::preferred_buffer_size();
 }
 
 raw_ostream &raw_fd_ostream::changeColor(enum Colors colors, bool bold,
@@ -316,7 +492,7 @@ raw_ostream &raw_fd_ostream::changeColor(enum Colors colors, bool bold,
     (colors == SAVEDCOLOR) ? sys::Process::OutputBold(bg)
     : sys::Process::OutputColor(colors, bold, bg);
   if (colorcode) {
-    unsigned len = strlen(colorcode);
+    size_t len = strlen(colorcode);
     write(colorcode, len);
     // don't account colors towards output characters
     pos -= len;
@@ -329,7 +505,7 @@ raw_ostream &raw_fd_ostream::resetColor() {
     flush();
   const char *colorcode = sys::Process::ResetColor();
   if (colorcode) {
-    unsigned len = strlen(colorcode);
+    size_t len = strlen(colorcode);
     write(colorcode, len);
     // don't account colors towards output characters
     pos -= len;
@@ -337,12 +513,18 @@ raw_ostream &raw_fd_ostream::resetColor() {
   return *this;
 }
 
+bool raw_fd_ostream::is_displayed() const {
+  return sys::Process::FileDescriptorIsDisplayed(FD);
+}
+
 //===----------------------------------------------------------------------===//
 //  raw_stdout/err_ostream
 //===----------------------------------------------------------------------===//
 
+// Set buffer settings to model stdout and stderr behavior.
+// Set standard error to be unbuffered by default.
 raw_stdout_ostream::raw_stdout_ostream():raw_fd_ostream(STDOUT_FILENO, false) {}
-raw_stderr_ostream::raw_stderr_ostream():raw_fd_ostream(STDERR_FILENO, false, 
+raw_stderr_ostream::raw_stderr_ostream():raw_fd_ostream(STDERR_FILENO, false,
                                                         true) {}
 
 // An out of line virtual method to provide a home for the class vtable.
@@ -363,23 +545,12 @@ raw_ostream &llvm::errs() {
   return S;
 }
 
-//===----------------------------------------------------------------------===//
-//  raw_os_ostream
-//===----------------------------------------------------------------------===//
-
-raw_os_ostream::~raw_os_ostream() {
-  flush();
-}
-
-void raw_os_ostream::write_impl(const char *Ptr, unsigned Size) {
-  OS.write(Ptr, Size);
+/// nulls() - This returns a reference to a raw_ostream which discards output.
+raw_ostream &llvm::nulls() {
+  static raw_null_ostream S;
+  return S;
 }
 
-uint64_t raw_os_ostream::current_pos() { return OS.tellp(); }
-
-uint64_t raw_os_ostream::tell() { 
-  return (uint64_t)OS.tellp() + GetNumBytesInBuffer(); 
-}
 
 //===----------------------------------------------------------------------===//
 //  raw_string_ostream
@@ -389,7 +560,7 @@ raw_string_ostream::~raw_string_ostream() {
   flush();
 }
 
-void raw_string_ostream::write_impl(const char *Ptr, unsigned Size) {
+void raw_string_ostream::write_impl(const char *Ptr, size_t Size) {
   OS.append(Ptr, Size);
 }
 
@@ -397,16 +568,84 @@ void raw_string_ostream::write_impl(const char *Ptr, unsigned Size) {
 //  raw_svector_ostream
 //===----------------------------------------------------------------------===//
 
+// The raw_svector_ostream implementation uses the SmallVector itself as the
+// buffer for the raw_ostream. We guarantee that the raw_ostream buffer is
+// always pointing past the end of the vector, but within the vector
+// 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) {
+  // 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
+  // the data is flushed). See the FIXME below.
+  OS.reserve(OS.size() + 128);
+  SetBuffer(OS.end(), OS.capacity() - OS.size());
+}
+
 raw_svector_ostream::~raw_svector_ostream() {
+  // FIXME: Prevent resizing during this flush().
+  flush();
+}
+
+/// resync - 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.
+void raw_svector_ostream::resync() {
+  assert(GetNumBytesInBuffer() == 0 && "Didn't flush before mutating vector");
+
+  if (OS.capacity() - OS.size() < 64)
+    OS.reserve(OS.capacity() * 2);
+  SetBuffer(OS.end(), OS.capacity() - OS.size());
+}
+
+void raw_svector_ostream::write_impl(const char *Ptr, size_t Size) {
+  // If we're writing bytes from the end of the buffer into the smallvector, we
+  // don't need to copy the bytes, just commit the bytes because they are
+  // already in the right place.
+  if (Ptr == OS.end()) {
+    assert(OS.size() + Size <= OS.capacity() && "Invalid write_impl() call!");
+    OS.set_size(OS.size() + Size);
+  } else {
+    assert(GetNumBytesInBuffer() == 0 &&
+           "Should be writing from buffer if some bytes in it");
+    // Otherwise, do copy the bytes.
+    OS.append(Ptr, Ptr+Size);
+  }
+
+  // Grow the vector if necessary.
+  if (OS.capacity() - OS.size() < 64)
+    OS.reserve(OS.capacity() * 2);
+
+  // Update the buffer position.
+  SetBuffer(OS.end(), OS.capacity() - OS.size());
+}
+
+uint64_t raw_svector_ostream::current_pos() const {
+   return OS.size();
+}
+
+StringRef raw_svector_ostream::str() {
   flush();
+  return StringRef(OS.begin(), OS.size());
 }
 
-void raw_svector_ostream::write_impl(const char *Ptr, unsigned Size) {
-  OS.append(Ptr, Ptr + Size);
+//===----------------------------------------------------------------------===//
+//  raw_null_ostream
+//===----------------------------------------------------------------------===//
+
+raw_null_ostream::~raw_null_ostream() {
+#ifndef NDEBUG
+  // ~raw_ostream asserts that the buffer is empty. This isn't necessary
+  // with raw_null_ostream, but it's better to have raw_null_ostream follow
+  // the rules than to change the rules just for raw_null_ostream.
+  flush();
+#endif
 }
 
-uint64_t raw_svector_ostream::current_pos() { return OS.size(); }
+void raw_null_ostream::write_impl(const char *Ptr, size_t Size) {
+}
 
-uint64_t raw_svector_ostream::tell() { 
-  return OS.size() + GetNumBytesInBuffer(); 
+uint64_t raw_null_ostream::current_pos() const {
+  return 0;
 }