1//===--- raw_ostream.cpp - Implement the raw_ostream classes --------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This implements support for bulk buffered stream output.
11//
12//===----------------------------------------------------------------------===//
13
14#include "llvm/Support/raw_ostream.h"
15#include "llvm/ADT/STLExtras.h"
16#include "llvm/ADT/SmallVector.h"
17#include "llvm/ADT/StringExtras.h"
18#include "llvm/Config/config.h"
19#include "llvm/Support/Compiler.h"
20#include "llvm/Support/ErrorHandling.h"
21#include "llvm/Support/Format.h"
22#include "llvm/Support/Process.h"
23#include "llvm/Support/Program.h"
24#include "llvm/Support/system_error.h"
25#include <cctype>
26#include <cerrno>
27#include <sys/stat.h>
28#include <sys/types.h>
29
30#if defined(HAVE_UNISTD_H)
31# include <unistd.h>
32#endif
33#if defined(HAVE_FCNTL_H)
34# include <fcntl.h>
35#endif
36#if defined(HAVE_SYS_UIO_H) && defined(HAVE_WRITEV)
37#  include <sys/uio.h>
38#endif
39
40#if defined(__CYGWIN__)
41#include <io.h>
42#endif
43
44#if defined(_MSC_VER)
45#include <io.h>
46#include <fcntl.h>
47#ifndef STDIN_FILENO
48# define STDIN_FILENO 0
49#endif
50#ifndef STDOUT_FILENO
51# define STDOUT_FILENO 1
52#endif
53#ifndef STDERR_FILENO
54# define STDERR_FILENO 2
55#endif
56#endif
57
58using namespace llvm;
59
60raw_ostream::~raw_ostream() {
61  // raw_ostream's subclasses should take care to flush the buffer
62  // in their destructors.
63  assert(OutBufCur == OutBufStart &&
64         "raw_ostream destructor called with non-empty buffer!");
65
66  if (BufferMode == InternalBuffer)
67    delete [] OutBufStart;
68}
69
70// An out of line virtual method to provide a home for the class vtable.
71void raw_ostream::handle() {}
72
73size_t raw_ostream::preferred_buffer_size() const {
74  // BUFSIZ is intended to be a reasonable default.
75  return BUFSIZ;
76}
77
78void raw_ostream::SetBuffered() {
79  // Ask the subclass to determine an appropriate buffer size.
80  if (size_t Size = preferred_buffer_size())
81    SetBufferSize(Size);
82  else
83    // It may return 0, meaning this stream should be unbuffered.
84    SetUnbuffered();
85}
86
87void raw_ostream::SetBufferAndMode(char *BufferStart, size_t Size,
88                                   BufferKind Mode) {
89  assert(((Mode == Unbuffered && BufferStart == 0 && Size == 0) ||
90          (Mode != Unbuffered && BufferStart && Size)) &&
91         "stream must be unbuffered or have at least one byte");
92  // Make sure the current buffer is free of content (we can't flush here; the
93  // child buffer management logic will be in write_impl).
94  assert(GetNumBytesInBuffer() == 0 && "Current buffer is non-empty!");
95
96  if (BufferMode == InternalBuffer)
97    delete [] OutBufStart;
98  OutBufStart = BufferStart;
99  OutBufEnd = OutBufStart+Size;
100  OutBufCur = OutBufStart;
101  BufferMode = Mode;
102
103  assert(OutBufStart <= OutBufEnd && "Invalid size!");
104}
105
106raw_ostream &raw_ostream::operator<<(unsigned long N) {
107  // Zero is a special case.
108  if (N == 0)
109    return *this << '0';
110
111  char NumberBuffer[20];
112  char *EndPtr = NumberBuffer+sizeof(NumberBuffer);
113  char *CurPtr = EndPtr;
114
115  while (N) {
116    *--CurPtr = '0' + char(N % 10);
117    N /= 10;
118  }
119  return write(CurPtr, EndPtr-CurPtr);
120}
121
122raw_ostream &raw_ostream::operator<<(long N) {
123  if (N <  0) {
124    *this << '-';
125    // Avoid undefined behavior on LONG_MIN with a cast.
126    N = -(unsigned long)N;
127  }
128
129  return this->operator<<(static_cast<unsigned long>(N));
130}
131
132raw_ostream &raw_ostream::operator<<(unsigned long long N) {
133  // Output using 32-bit div/mod when possible.
134  if (N == static_cast<unsigned long>(N))
135    return this->operator<<(static_cast<unsigned long>(N));
136
137  char NumberBuffer[20];
138  char *EndPtr = NumberBuffer+sizeof(NumberBuffer);
139  char *CurPtr = EndPtr;
140
141  while (N) {
142    *--CurPtr = '0' + char(N % 10);
143    N /= 10;
144  }
145  return write(CurPtr, EndPtr-CurPtr);
146}
147
148raw_ostream &raw_ostream::operator<<(long long N) {
149  if (N < 0) {
150    *this << '-';
151    // Avoid undefined behavior on INT64_MIN with a cast.
152    N = -(unsigned long long)N;
153  }
154
155  return this->operator<<(static_cast<unsigned long long>(N));
156}
157
158raw_ostream &raw_ostream::write_hex(unsigned long long N) {
159  // Zero is a special case.
160  if (N == 0)
161    return *this << '0';
162
163  char NumberBuffer[20];
164  char *EndPtr = NumberBuffer+sizeof(NumberBuffer);
165  char *CurPtr = EndPtr;
166
167  while (N) {
168    uintptr_t x = N % 16;
169    *--CurPtr = (x < 10 ? '0' + x : 'a' + x - 10);
170    N /= 16;
171  }
172
173  return write(CurPtr, EndPtr-CurPtr);
174}
175
176raw_ostream &raw_ostream::write_escaped(StringRef Str,
177                                        bool UseHexEscapes) {
178  for (unsigned i = 0, e = Str.size(); i != e; ++i) {
179    unsigned char c = Str[i];
180
181    switch (c) {
182    case '\\':
183      *this << '\\' << '\\';
184      break;
185    case '\t':
186      *this << '\\' << 't';
187      break;
188    case '\n':
189      *this << '\\' << 'n';
190      break;
191    case '"':
192      *this << '\\' << '"';
193      break;
194    default:
195      if (std::isprint(c)) {
196        *this << c;
197        break;
198      }
199
200      // Write out the escaped representation.
201      if (UseHexEscapes) {
202        *this << '\\' << 'x';
203        *this << hexdigit((c >> 4 & 0xF));
204        *this << hexdigit((c >> 0) & 0xF);
205      } else {
206        // Always use a full 3-character octal escape.
207        *this << '\\';
208        *this << char('0' + ((c >> 6) & 7));
209        *this << char('0' + ((c >> 3) & 7));
210        *this << char('0' + ((c >> 0) & 7));
211      }
212    }
213  }
214
215  return *this;
216}
217
218raw_ostream &raw_ostream::operator<<(const void *P) {
219  *this << '0' << 'x';
220
221  return write_hex((uintptr_t) P);
222}
223
224raw_ostream &raw_ostream::operator<<(double N) {
225#ifdef _WIN32
226  // On MSVCRT and compatible, output of %e is incompatible to Posix
227  // by default. Number of exponent digits should be at least 2. "%+03d"
228  // FIXME: Implement our formatter to here or Support/Format.h!
229  int fpcl = _fpclass(N);
230
231  // negative zero
232  if (fpcl == _FPCLASS_NZ)
233    return *this << "-0.000000e+00";
234
235  char buf[16];
236  unsigned len;
237  len = snprintf(buf, sizeof(buf), "%e", N);
238  if (len <= sizeof(buf) - 2) {
239    if (len >= 5 && buf[len - 5] == 'e' && buf[len - 3] == '0') {
240      int cs = buf[len - 4];
241      if (cs == '+' || cs == '-') {
242        int c1 = buf[len - 2];
243        int c0 = buf[len - 1];
244        if (isdigit(static_cast<unsigned char>(c1)) &&
245            isdigit(static_cast<unsigned char>(c0))) {
246          // Trim leading '0': "...e+012" -> "...e+12\0"
247          buf[len - 3] = c1;
248          buf[len - 2] = c0;
249          buf[--len] = 0;
250        }
251      }
252    }
253    return this->operator<<(buf);
254  }
255#endif
256  return this->operator<<(format("%e", N));
257}
258
259
260
261void raw_ostream::flush_nonempty() {
262  assert(OutBufCur > OutBufStart && "Invalid call to flush_nonempty.");
263  size_t Length = OutBufCur - OutBufStart;
264  OutBufCur = OutBufStart;
265  write_impl(OutBufStart, Length);
266}
267
268raw_ostream &raw_ostream::write(unsigned char C) {
269  // Group exceptional cases into a single branch.
270  if (LLVM_UNLIKELY(OutBufCur >= OutBufEnd)) {
271    if (LLVM_UNLIKELY(!OutBufStart)) {
272      if (BufferMode == Unbuffered) {
273        write_impl(reinterpret_cast<char*>(&C), 1);
274        return *this;
275      }
276      // Set up a buffer and start over.
277      SetBuffered();
278      return write(C);
279    }
280
281    flush_nonempty();
282  }
283
284  *OutBufCur++ = C;
285  return *this;
286}
287
288raw_ostream &raw_ostream::write(const char *Ptr, size_t Size) {
289  // Group exceptional cases into a single branch.
290  if (LLVM_UNLIKELY(size_t(OutBufEnd - OutBufCur) < Size)) {
291    if (LLVM_UNLIKELY(!OutBufStart)) {
292      if (BufferMode == Unbuffered) {
293        write_impl(Ptr, Size);
294        return *this;
295      }
296      // Set up a buffer and start over.
297      SetBuffered();
298      return write(Ptr, Size);
299    }
300
301    size_t NumBytes = OutBufEnd - OutBufCur;
302
303    // If the buffer is empty at this point we have a string that is larger
304    // than the buffer. Directly write the chunk that is a multiple of the
305    // preferred buffer size and put the remainder in the buffer.
306    if (LLVM_UNLIKELY(OutBufCur == OutBufStart)) {
307      size_t BytesToWrite = Size - (Size % NumBytes);
308      write_impl(Ptr, BytesToWrite);
309      size_t BytesRemaining = Size - BytesToWrite;
310      if (BytesRemaining > size_t(OutBufEnd - OutBufCur)) {
311        // Too much left over to copy into our buffer.
312        return write(Ptr + BytesToWrite, BytesRemaining);
313      }
314      copy_to_buffer(Ptr + BytesToWrite, BytesRemaining);
315      return *this;
316    }
317
318    // We don't have enough space in the buffer to fit the string in. Insert as
319    // much as possible, flush and start over with the remainder.
320    copy_to_buffer(Ptr, NumBytes);
321    flush_nonempty();
322    return write(Ptr + NumBytes, Size - NumBytes);
323  }
324
325  copy_to_buffer(Ptr, Size);
326
327  return *this;
328}
329
330void raw_ostream::copy_to_buffer(const char *Ptr, size_t Size) {
331  assert(Size <= size_t(OutBufEnd - OutBufCur) && "Buffer overrun!");
332
333  // Handle short strings specially, memcpy isn't very good at very short
334  // strings.
335  switch (Size) {
336  case 4: OutBufCur[3] = Ptr[3]; // FALL THROUGH
337  case 3: OutBufCur[2] = Ptr[2]; // FALL THROUGH
338  case 2: OutBufCur[1] = Ptr[1]; // FALL THROUGH
339  case 1: OutBufCur[0] = Ptr[0]; // FALL THROUGH
340  case 0: break;
341  default:
342    memcpy(OutBufCur, Ptr, Size);
343    break;
344  }
345
346  OutBufCur += Size;
347}
348
349// Formatted output.
350raw_ostream &raw_ostream::operator<<(const format_object_base &Fmt) {
351  // If we have more than a few bytes left in our output buffer, try
352  // formatting directly onto its end.
353  size_t NextBufferSize = 127;
354  size_t BufferBytesLeft = OutBufEnd - OutBufCur;
355  if (BufferBytesLeft > 3) {
356    size_t BytesUsed = Fmt.print(OutBufCur, BufferBytesLeft);
357
358    // Common case is that we have plenty of space.
359    if (BytesUsed <= BufferBytesLeft) {
360      OutBufCur += BytesUsed;
361      return *this;
362    }
363
364    // Otherwise, we overflowed and the return value tells us the size to try
365    // again with.
366    NextBufferSize = BytesUsed;
367  }
368
369  // If we got here, we didn't have enough space in the output buffer for the
370  // string.  Try printing into a SmallVector that is resized to have enough
371  // space.  Iterate until we win.
372  SmallVector<char, 128> V;
373
374  while (1) {
375    V.resize(NextBufferSize);
376
377    // Try formatting into the SmallVector.
378    size_t BytesUsed = Fmt.print(V.data(), NextBufferSize);
379
380    // If BytesUsed fit into the vector, we win.
381    if (BytesUsed <= NextBufferSize)
382      return write(V.data(), BytesUsed);
383
384    // Otherwise, try again with a new size.
385    assert(BytesUsed > NextBufferSize && "Didn't grow buffer!?");
386    NextBufferSize = BytesUsed;
387  }
388}
389
390/// indent - Insert 'NumSpaces' spaces.
391raw_ostream &raw_ostream::indent(unsigned NumSpaces) {
392  static const char Spaces[] = "                                "
393                               "                                "
394                               "                ";
395
396  // Usually the indentation is small, handle it with a fastpath.
397  if (NumSpaces < array_lengthof(Spaces))
398    return write(Spaces, NumSpaces);
399
400  while (NumSpaces) {
401    unsigned NumToWrite = std::min(NumSpaces,
402                                   (unsigned)array_lengthof(Spaces)-1);
403    write(Spaces, NumToWrite);
404    NumSpaces -= NumToWrite;
405  }
406  return *this;
407}
408
409
410//===----------------------------------------------------------------------===//
411//  Formatted Output
412//===----------------------------------------------------------------------===//
413
414// Out of line virtual method.
415void format_object_base::home() {
416}
417
418//===----------------------------------------------------------------------===//
419//  raw_fd_ostream
420//===----------------------------------------------------------------------===//
421
422/// raw_fd_ostream - Open the specified file for writing. If an error
423/// occurs, information about the error is put into ErrorInfo, and the
424/// stream should be immediately destroyed; the string will be empty
425/// if no error occurred.
426raw_fd_ostream::raw_fd_ostream(const char *Filename, std::string &ErrorInfo,
427                               unsigned Flags)
428  : Error(false), UseAtomicWrites(false), pos(0)
429{
430  assert(Filename != 0 && "Filename is null");
431  // Verify that we don't have both "append" and "excl".
432  assert((!(Flags & F_Excl) || !(Flags & F_Append)) &&
433         "Cannot specify both 'excl' and 'append' file creation flags!");
434
435  ErrorInfo.clear();
436
437  // Handle "-" as stdout. Note that when we do this, we consider ourself
438  // the owner of stdout. This means that we can do things like close the
439  // file descriptor when we're done and set the "binary" flag globally.
440  if (Filename[0] == '-' && Filename[1] == 0) {
441    FD = STDOUT_FILENO;
442    // If user requested binary then put stdout into binary mode if
443    // possible.
444    if (Flags & F_Binary)
445      sys::Program::ChangeStdoutToBinary();
446    // Close stdout when we're done, to detect any output errors.
447    ShouldClose = true;
448    return;
449  }
450
451  int OpenFlags = O_WRONLY|O_CREAT;
452#ifdef O_BINARY
453  if (Flags & F_Binary)
454    OpenFlags |= O_BINARY;
455#endif
456
457  if (Flags & F_Append)
458    OpenFlags |= O_APPEND;
459  else
460    OpenFlags |= O_TRUNC;
461  if (Flags & F_Excl)
462    OpenFlags |= O_EXCL;
463
464  while ((FD = open(Filename, OpenFlags, 0664)) < 0) {
465    if (errno != EINTR) {
466      ErrorInfo = "Error opening output file '" + std::string(Filename) + "'";
467      ShouldClose = false;
468      return;
469    }
470  }
471
472  // Ok, we successfully opened the file, so it'll need to be closed.
473  ShouldClose = true;
474}
475
476/// raw_fd_ostream ctor - FD is the file descriptor that this writes to.  If
477/// ShouldClose is true, this closes the file when the stream is destroyed.
478raw_fd_ostream::raw_fd_ostream(int fd, bool shouldClose, bool unbuffered)
479  : raw_ostream(unbuffered), FD(fd),
480    ShouldClose(shouldClose), Error(false), UseAtomicWrites(false) {
481#ifdef O_BINARY
482  // Setting STDOUT and STDERR to binary mode is necessary in Win32
483  // to avoid undesirable linefeed conversion.
484  if (fd == STDOUT_FILENO || fd == STDERR_FILENO)
485    setmode(fd, O_BINARY);
486#endif
487
488  // Get the starting position.
489  off_t loc = ::lseek(FD, 0, SEEK_CUR);
490  if (loc == (off_t)-1)
491    pos = 0;
492  else
493    pos = static_cast<uint64_t>(loc);
494}
495
496raw_fd_ostream::~raw_fd_ostream() {
497  if (FD >= 0) {
498    flush();
499    if (ShouldClose)
500      while (::close(FD) != 0)
501        if (errno != EINTR) {
502          error_detected();
503          break;
504        }
505  }
506
507#ifdef __MINGW32__
508  // On mingw, global dtors should not call exit().
509  // report_fatal_error() invokes exit(). We know report_fatal_error()
510  // might not write messages to stderr when any errors were detected
511  // on FD == 2.
512  if (FD == 2) return;
513#endif
514
515  // If there are any pending errors, report them now. Clients wishing
516  // to avoid report_fatal_error calls should check for errors with
517  // has_error() and clear the error flag with clear_error() before
518  // destructing raw_ostream objects which may have errors.
519  if (has_error())
520    report_fatal_error("IO failure on output stream.");
521}
522
523
524void raw_fd_ostream::write_impl(const char *Ptr, size_t Size) {
525  assert(FD >= 0 && "File already closed.");
526  pos += Size;
527
528  do {
529    ssize_t ret;
530
531    // Check whether we should attempt to use atomic writes.
532    if (LLVM_LIKELY(!UseAtomicWrites)) {
533      ret = ::write(FD, Ptr, Size);
534    } else {
535      // Use ::writev() where available.
536#if defined(HAVE_WRITEV)
537      const void *Addr = static_cast<const void *>(Ptr);
538      struct iovec IOV = {const_cast<void *>(Addr), Size };
539      ret = ::writev(FD, &IOV, 1);
540#else
541      ret = ::write(FD, Ptr, Size);
542#endif
543    }
544
545    if (ret < 0) {
546      // If it's a recoverable error, swallow it and retry the write.
547      //
548      // Ideally we wouldn't ever see EAGAIN or EWOULDBLOCK here, since
549      // raw_ostream isn't designed to do non-blocking I/O. However, some
550      // programs, such as old versions of bjam, have mistakenly used
551      // O_NONBLOCK. For compatibility, emulate blocking semantics by
552      // spinning until the write succeeds. If you don't want spinning,
553      // don't use O_NONBLOCK file descriptors with raw_ostream.
554      if (errno == EINTR || errno == EAGAIN
555#ifdef EWOULDBLOCK
556          || errno == EWOULDBLOCK
557#endif
558          )
559        continue;
560
561      // Otherwise it's a non-recoverable error. Note it and quit.
562      error_detected();
563      break;
564    }
565
566    // The write may have written some or all of the data. Update the
567    // size and buffer pointer to reflect the remainder that needs
568    // to be written. If there are no bytes left, we're done.
569    Ptr += ret;
570    Size -= ret;
571  } while (Size > 0);
572}
573
574void raw_fd_ostream::close() {
575  assert(ShouldClose);
576  ShouldClose = false;
577  flush();
578  while (::close(FD) != 0)
579    if (errno != EINTR) {
580      error_detected();
581      break;
582    }
583  FD = -1;
584}
585
586uint64_t raw_fd_ostream::seek(uint64_t off) {
587  flush();
588  pos = ::lseek(FD, off, SEEK_SET);
589  if (pos != off)
590    error_detected();
591  return pos;
592}
593
594size_t raw_fd_ostream::preferred_buffer_size() const {
595#if !defined(_MSC_VER) && !defined(__MINGW32__) && !defined(__minix)
596  // Windows and Minix have no st_blksize.
597  assert(FD >= 0 && "File not yet open!");
598  struct stat statbuf;
599  if (fstat(FD, &statbuf) != 0)
600    return 0;
601
602  // If this is a terminal, don't use buffering. Line buffering
603  // would be a more traditional thing to do, but it's not worth
604  // the complexity.
605  if (S_ISCHR(statbuf.st_mode) && isatty(FD))
606    return 0;
607  // Return the preferred block size.
608  return statbuf.st_blksize;
609#else
610  return raw_ostream::preferred_buffer_size();
611#endif
612}
613
614raw_ostream &raw_fd_ostream::changeColor(enum Colors colors, bool bold,
615                                         bool bg) {
616  if (sys::Process::ColorNeedsFlush())
617    flush();
618  const char *colorcode =
619    (colors == SAVEDCOLOR) ? sys::Process::OutputBold(bg)
620    : sys::Process::OutputColor(colors, bold, bg);
621  if (colorcode) {
622    size_t len = strlen(colorcode);
623    write(colorcode, len);
624    // don't account colors towards output characters
625    pos -= len;
626  }
627  return *this;
628}
629
630raw_ostream &raw_fd_ostream::resetColor() {
631  if (sys::Process::ColorNeedsFlush())
632    flush();
633  const char *colorcode = sys::Process::ResetColor();
634  if (colorcode) {
635    size_t len = strlen(colorcode);
636    write(colorcode, len);
637    // don't account colors towards output characters
638    pos -= len;
639  }
640  return *this;
641}
642
643raw_ostream &raw_fd_ostream::reverseColor() {
644  if (sys::Process::ColorNeedsFlush())
645    flush();
646  const char *colorcode = sys::Process::OutputReverse();
647  if (colorcode) {
648    size_t len = strlen(colorcode);
649    write(colorcode, len);
650    // don't account colors towards output characters
651    pos -= len;
652  }
653  return *this;
654}
655
656bool raw_fd_ostream::is_displayed() const {
657  return sys::Process::FileDescriptorIsDisplayed(FD);
658}
659
660bool raw_fd_ostream::has_colors() const {
661  return sys::Process::FileDescriptorHasColors(FD);
662}
663
664//===----------------------------------------------------------------------===//
665//  outs(), errs(), nulls()
666//===----------------------------------------------------------------------===//
667
668/// outs() - This returns a reference to a raw_ostream for standard output.
669/// Use it like: outs() << "foo" << "bar";
670raw_ostream &llvm::outs() {
671  // Set buffer settings to model stdout behavior.
672  // Delete the file descriptor when the program exists, forcing error
673  // detection. If you don't want this behavior, don't use outs().
674  static raw_fd_ostream S(STDOUT_FILENO, true);
675  return S;
676}
677
678/// errs() - This returns a reference to a raw_ostream for standard error.
679/// Use it like: errs() << "foo" << "bar";
680raw_ostream &llvm::errs() {
681  // Set standard error to be unbuffered by default.
682  static raw_fd_ostream S(STDERR_FILENO, false, true);
683  return S;
684}
685
686/// nulls() - This returns a reference to a raw_ostream which discards output.
687raw_ostream &llvm::nulls() {
688  static raw_null_ostream S;
689  return S;
690}
691
692
693//===----------------------------------------------------------------------===//
694//  raw_string_ostream
695//===----------------------------------------------------------------------===//
696
697raw_string_ostream::~raw_string_ostream() {
698  flush();
699}
700
701void raw_string_ostream::write_impl(const char *Ptr, size_t Size) {
702  OS.append(Ptr, Size);
703}
704
705//===----------------------------------------------------------------------===//
706//  raw_svector_ostream
707//===----------------------------------------------------------------------===//
708
709// The raw_svector_ostream implementation uses the SmallVector itself as the
710// buffer for the raw_ostream. We guarantee that the raw_ostream buffer is
711// always pointing past the end of the vector, but within the vector
712// capacity. This allows raw_ostream to write directly into the correct place,
713// and we only need to set the vector size when the data is flushed.
714
715raw_svector_ostream::raw_svector_ostream(SmallVectorImpl<char> &O) : OS(O) {
716  // Set up the initial external buffer. We make sure that the buffer has at
717  // least 128 bytes free; raw_ostream itself only requires 64, but we want to
718  // make sure that we don't grow the buffer unnecessarily on destruction (when
719  // the data is flushed). See the FIXME below.
720  OS.reserve(OS.size() + 128);
721  SetBuffer(OS.end(), OS.capacity() - OS.size());
722}
723
724raw_svector_ostream::~raw_svector_ostream() {
725  // FIXME: Prevent resizing during this flush().
726  flush();
727}
728
729/// resync - This is called when the SmallVector we're appending to is changed
730/// outside of the raw_svector_ostream's control.  It is only safe to do this
731/// if the raw_svector_ostream has previously been flushed.
732void raw_svector_ostream::resync() {
733  assert(GetNumBytesInBuffer() == 0 && "Didn't flush before mutating vector");
734
735  if (OS.capacity() - OS.size() < 64)
736    OS.reserve(OS.capacity() * 2);
737  SetBuffer(OS.end(), OS.capacity() - OS.size());
738}
739
740void raw_svector_ostream::write_impl(const char *Ptr, size_t Size) {
741  // If we're writing bytes from the end of the buffer into the smallvector, we
742  // don't need to copy the bytes, just commit the bytes because they are
743  // already in the right place.
744  if (Ptr == OS.end()) {
745    assert(OS.size() + Size <= OS.capacity() && "Invalid write_impl() call!");
746    OS.set_size(OS.size() + Size);
747  } else {
748    assert(GetNumBytesInBuffer() == 0 &&
749           "Should be writing from buffer if some bytes in it");
750    // Otherwise, do copy the bytes.
751    OS.append(Ptr, Ptr+Size);
752  }
753
754  // Grow the vector if necessary.
755  if (OS.capacity() - OS.size() < 64)
756    OS.reserve(OS.capacity() * 2);
757
758  // Update the buffer position.
759  SetBuffer(OS.end(), OS.capacity() - OS.size());
760}
761
762uint64_t raw_svector_ostream::current_pos() const {
763   return OS.size();
764}
765
766StringRef raw_svector_ostream::str() {
767  flush();
768  return StringRef(OS.begin(), OS.size());
769}
770
771//===----------------------------------------------------------------------===//
772//  raw_null_ostream
773//===----------------------------------------------------------------------===//
774
775raw_null_ostream::~raw_null_ostream() {
776#ifndef NDEBUG
777  // ~raw_ostream asserts that the buffer is empty. This isn't necessary
778  // with raw_null_ostream, but it's better to have raw_null_ostream follow
779  // the rules than to change the rules just for raw_null_ostream.
780  flush();
781#endif
782}
783
784void raw_null_ostream::write_impl(const char *Ptr, size_t Size) {
785}
786
787uint64_t raw_null_ostream::current_pos() const {
788  return 0;
789}
790