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/FileSystem.h"
22 #include "llvm/Support/Format.h"
23 #include "llvm/Support/Process.h"
24 #include "llvm/Support/Program.h"
25 #include <cctype>
26 #include <cerrno>
27 #include <sys/stat.h>
28 #include <system_error>
29
30 // <fcntl.h> may provide O_BINARY.
31 #if defined(HAVE_FCNTL_H)
32 # include <fcntl.h>
33 #endif
34
35 #if defined(HAVE_UNISTD_H)
36 # include <unistd.h>
37 #endif
38 #if defined(HAVE_SYS_UIO_H) && defined(HAVE_WRITEV)
39 # include <sys/uio.h>
40 #endif
41
42 #if defined(__CYGWIN__)
43 #include <io.h>
44 #endif
45
46 #if defined(_MSC_VER)
47 #include <io.h>
48 #ifndef STDIN_FILENO
49 # define STDIN_FILENO 0
50 #endif
51 #ifndef STDOUT_FILENO
52 # define STDOUT_FILENO 1
53 #endif
54 #ifndef STDERR_FILENO
55 # define STDERR_FILENO 2
56 #endif
57 #endif
58
59 using namespace llvm;
60
~raw_ostream()61 raw_ostream::~raw_ostream() {
62 // raw_ostream's subclasses should take care to flush the buffer
63 // in their destructors.
64 assert(OutBufCur == OutBufStart &&
65 "raw_ostream destructor called with non-empty buffer!");
66
67 if (BufferMode == InternalBuffer)
68 delete [] OutBufStart;
69 }
70
71 // An out of line virtual method to provide a home for the class vtable.
handle()72 void raw_ostream::handle() {}
73
preferred_buffer_size() const74 size_t raw_ostream::preferred_buffer_size() const {
75 // BUFSIZ is intended to be a reasonable default.
76 return BUFSIZ;
77 }
78
SetBuffered()79 void raw_ostream::SetBuffered() {
80 // Ask the subclass to determine an appropriate buffer size.
81 if (size_t Size = preferred_buffer_size())
82 SetBufferSize(Size);
83 else
84 // It may return 0, meaning this stream should be unbuffered.
85 SetUnbuffered();
86 }
87
SetBufferAndMode(char * BufferStart,size_t Size,BufferKind Mode)88 void raw_ostream::SetBufferAndMode(char *BufferStart, size_t Size,
89 BufferKind Mode) {
90 assert(((Mode == Unbuffered && !BufferStart && Size == 0) ||
91 (Mode != Unbuffered && BufferStart && Size != 0)) &&
92 "stream must be unbuffered or have at least one byte");
93 // Make sure the current buffer is free of content (we can't flush here; the
94 // child buffer management logic will be in write_impl).
95 assert(GetNumBytesInBuffer() == 0 && "Current buffer is non-empty!");
96
97 if (BufferMode == InternalBuffer)
98 delete [] OutBufStart;
99 OutBufStart = BufferStart;
100 OutBufEnd = OutBufStart+Size;
101 OutBufCur = OutBufStart;
102 BufferMode = Mode;
103
104 assert(OutBufStart <= OutBufEnd && "Invalid size!");
105 }
106
operator <<(unsigned long N)107 raw_ostream &raw_ostream::operator<<(unsigned long N) {
108 // Zero is a special case.
109 if (N == 0)
110 return *this << '0';
111
112 char NumberBuffer[20];
113 char *EndPtr = NumberBuffer+sizeof(NumberBuffer);
114 char *CurPtr = EndPtr;
115
116 while (N) {
117 *--CurPtr = '0' + char(N % 10);
118 N /= 10;
119 }
120 return write(CurPtr, EndPtr-CurPtr);
121 }
122
operator <<(long N)123 raw_ostream &raw_ostream::operator<<(long N) {
124 if (N < 0) {
125 *this << '-';
126 // Avoid undefined behavior on LONG_MIN with a cast.
127 N = -(unsigned long)N;
128 }
129
130 return this->operator<<(static_cast<unsigned long>(N));
131 }
132
operator <<(unsigned long long N)133 raw_ostream &raw_ostream::operator<<(unsigned long long N) {
134 // Output using 32-bit div/mod when possible.
135 if (N == static_cast<unsigned long>(N))
136 return this->operator<<(static_cast<unsigned long>(N));
137
138 char NumberBuffer[20];
139 char *EndPtr = NumberBuffer+sizeof(NumberBuffer);
140 char *CurPtr = EndPtr;
141
142 while (N) {
143 *--CurPtr = '0' + char(N % 10);
144 N /= 10;
145 }
146 return write(CurPtr, EndPtr-CurPtr);
147 }
148
operator <<(long long N)149 raw_ostream &raw_ostream::operator<<(long long N) {
150 if (N < 0) {
151 *this << '-';
152 // Avoid undefined behavior on INT64_MIN with a cast.
153 N = -(unsigned long long)N;
154 }
155
156 return this->operator<<(static_cast<unsigned long long>(N));
157 }
158
write_hex(unsigned long long N)159 raw_ostream &raw_ostream::write_hex(unsigned long long N) {
160 // Zero is a special case.
161 if (N == 0)
162 return *this << '0';
163
164 char NumberBuffer[20];
165 char *EndPtr = NumberBuffer+sizeof(NumberBuffer);
166 char *CurPtr = EndPtr;
167
168 while (N) {
169 uintptr_t x = N % 16;
170 *--CurPtr = (x < 10 ? '0' + x : 'a' + x - 10);
171 N /= 16;
172 }
173
174 return write(CurPtr, EndPtr-CurPtr);
175 }
176
write_escaped(StringRef Str,bool UseHexEscapes)177 raw_ostream &raw_ostream::write_escaped(StringRef Str,
178 bool UseHexEscapes) {
179 for (unsigned i = 0, e = Str.size(); i != e; ++i) {
180 unsigned char c = Str[i];
181
182 switch (c) {
183 case '\\':
184 *this << '\\' << '\\';
185 break;
186 case '\t':
187 *this << '\\' << 't';
188 break;
189 case '\n':
190 *this << '\\' << 'n';
191 break;
192 case '"':
193 *this << '\\' << '"';
194 break;
195 default:
196 if (std::isprint(c)) {
197 *this << c;
198 break;
199 }
200
201 // Write out the escaped representation.
202 if (UseHexEscapes) {
203 *this << '\\' << 'x';
204 *this << hexdigit((c >> 4 & 0xF));
205 *this << hexdigit((c >> 0) & 0xF);
206 } else {
207 // Always use a full 3-character octal escape.
208 *this << '\\';
209 *this << char('0' + ((c >> 6) & 7));
210 *this << char('0' + ((c >> 3) & 7));
211 *this << char('0' + ((c >> 0) & 7));
212 }
213 }
214 }
215
216 return *this;
217 }
218
operator <<(const void * P)219 raw_ostream &raw_ostream::operator<<(const void *P) {
220 *this << '0' << 'x';
221
222 return write_hex((uintptr_t) P);
223 }
224
operator <<(double N)225 raw_ostream &raw_ostream::operator<<(double N) {
226 #ifdef _WIN32
227 // On MSVCRT and compatible, output of %e is incompatible to Posix
228 // by default. Number of exponent digits should be at least 2. "%+03d"
229 // FIXME: Implement our formatter to here or Support/Format.h!
230 #if __cplusplus >= 201103L && defined(__MINGW32__)
231 // FIXME: It should be generic to C++11.
232 if (N == 0.0 && std::signbit(N))
233 return *this << "-0.000000e+00";
234 #else
235 int fpcl = _fpclass(N);
236
237 // negative zero
238 if (fpcl == _FPCLASS_NZ)
239 return *this << "-0.000000e+00";
240 #endif
241
242 char buf[16];
243 unsigned len;
244 len = snprintf(buf, sizeof(buf), "%e", N);
245 if (len <= sizeof(buf) - 2) {
246 if (len >= 5 && buf[len - 5] == 'e' && buf[len - 3] == '0') {
247 int cs = buf[len - 4];
248 if (cs == '+' || cs == '-') {
249 int c1 = buf[len - 2];
250 int c0 = buf[len - 1];
251 if (isdigit(static_cast<unsigned char>(c1)) &&
252 isdigit(static_cast<unsigned char>(c0))) {
253 // Trim leading '0': "...e+012" -> "...e+12\0"
254 buf[len - 3] = c1;
255 buf[len - 2] = c0;
256 buf[--len] = 0;
257 }
258 }
259 }
260 return this->operator<<(buf);
261 }
262 #endif
263 return this->operator<<(format("%e", N));
264 }
265
266
267
flush_nonempty()268 void raw_ostream::flush_nonempty() {
269 assert(OutBufCur > OutBufStart && "Invalid call to flush_nonempty.");
270 size_t Length = OutBufCur - OutBufStart;
271 OutBufCur = OutBufStart;
272 write_impl(OutBufStart, Length);
273 }
274
write(unsigned char C)275 raw_ostream &raw_ostream::write(unsigned char C) {
276 // Group exceptional cases into a single branch.
277 if (LLVM_UNLIKELY(OutBufCur >= OutBufEnd)) {
278 if (LLVM_UNLIKELY(!OutBufStart)) {
279 if (BufferMode == Unbuffered) {
280 write_impl(reinterpret_cast<char*>(&C), 1);
281 return *this;
282 }
283 // Set up a buffer and start over.
284 SetBuffered();
285 return write(C);
286 }
287
288 flush_nonempty();
289 }
290
291 *OutBufCur++ = C;
292 return *this;
293 }
294
write(const char * Ptr,size_t Size)295 raw_ostream &raw_ostream::write(const char *Ptr, size_t Size) {
296 // Group exceptional cases into a single branch.
297 if (LLVM_UNLIKELY(size_t(OutBufEnd - OutBufCur) < Size)) {
298 if (LLVM_UNLIKELY(!OutBufStart)) {
299 if (BufferMode == Unbuffered) {
300 write_impl(Ptr, Size);
301 return *this;
302 }
303 // Set up a buffer and start over.
304 SetBuffered();
305 return write(Ptr, Size);
306 }
307
308 size_t NumBytes = OutBufEnd - OutBufCur;
309
310 // If the buffer is empty at this point we have a string that is larger
311 // than the buffer. Directly write the chunk that is a multiple of the
312 // preferred buffer size and put the remainder in the buffer.
313 if (LLVM_UNLIKELY(OutBufCur == OutBufStart)) {
314 size_t BytesToWrite = Size - (Size % NumBytes);
315 write_impl(Ptr, BytesToWrite);
316 size_t BytesRemaining = Size - BytesToWrite;
317 if (BytesRemaining > size_t(OutBufEnd - OutBufCur)) {
318 // Too much left over to copy into our buffer.
319 return write(Ptr + BytesToWrite, BytesRemaining);
320 }
321 copy_to_buffer(Ptr + BytesToWrite, BytesRemaining);
322 return *this;
323 }
324
325 // We don't have enough space in the buffer to fit the string in. Insert as
326 // much as possible, flush and start over with the remainder.
327 copy_to_buffer(Ptr, NumBytes);
328 flush_nonempty();
329 return write(Ptr + NumBytes, Size - NumBytes);
330 }
331
332 copy_to_buffer(Ptr, Size);
333
334 return *this;
335 }
336
copy_to_buffer(const char * Ptr,size_t Size)337 void raw_ostream::copy_to_buffer(const char *Ptr, size_t Size) {
338 assert(Size <= size_t(OutBufEnd - OutBufCur) && "Buffer overrun!");
339
340 // Handle short strings specially, memcpy isn't very good at very short
341 // strings.
342 switch (Size) {
343 case 4: OutBufCur[3] = Ptr[3]; // FALL THROUGH
344 case 3: OutBufCur[2] = Ptr[2]; // FALL THROUGH
345 case 2: OutBufCur[1] = Ptr[1]; // FALL THROUGH
346 case 1: OutBufCur[0] = Ptr[0]; // FALL THROUGH
347 case 0: break;
348 default:
349 memcpy(OutBufCur, Ptr, Size);
350 break;
351 }
352
353 OutBufCur += Size;
354 }
355
356 // Formatted output.
operator <<(const format_object_base & Fmt)357 raw_ostream &raw_ostream::operator<<(const format_object_base &Fmt) {
358 // If we have more than a few bytes left in our output buffer, try
359 // formatting directly onto its end.
360 size_t NextBufferSize = 127;
361 size_t BufferBytesLeft = OutBufEnd - OutBufCur;
362 if (BufferBytesLeft > 3) {
363 size_t BytesUsed = Fmt.print(OutBufCur, BufferBytesLeft);
364
365 // Common case is that we have plenty of space.
366 if (BytesUsed <= BufferBytesLeft) {
367 OutBufCur += BytesUsed;
368 return *this;
369 }
370
371 // Otherwise, we overflowed and the return value tells us the size to try
372 // again with.
373 NextBufferSize = BytesUsed;
374 }
375
376 // If we got here, we didn't have enough space in the output buffer for the
377 // string. Try printing into a SmallVector that is resized to have enough
378 // space. Iterate until we win.
379 SmallVector<char, 128> V;
380
381 while (1) {
382 V.resize(NextBufferSize);
383
384 // Try formatting into the SmallVector.
385 size_t BytesUsed = Fmt.print(V.data(), NextBufferSize);
386
387 // If BytesUsed fit into the vector, we win.
388 if (BytesUsed <= NextBufferSize)
389 return write(V.data(), BytesUsed);
390
391 // Otherwise, try again with a new size.
392 assert(BytesUsed > NextBufferSize && "Didn't grow buffer!?");
393 NextBufferSize = BytesUsed;
394 }
395 }
396
397 /// indent - Insert 'NumSpaces' spaces.
indent(unsigned NumSpaces)398 raw_ostream &raw_ostream::indent(unsigned NumSpaces) {
399 static const char Spaces[] = " "
400 " "
401 " ";
402
403 // Usually the indentation is small, handle it with a fastpath.
404 if (NumSpaces < array_lengthof(Spaces))
405 return write(Spaces, NumSpaces);
406
407 while (NumSpaces) {
408 unsigned NumToWrite = std::min(NumSpaces,
409 (unsigned)array_lengthof(Spaces)-1);
410 write(Spaces, NumToWrite);
411 NumSpaces -= NumToWrite;
412 }
413 return *this;
414 }
415
416
417 //===----------------------------------------------------------------------===//
418 // Formatted Output
419 //===----------------------------------------------------------------------===//
420
421 // Out of line virtual method.
home()422 void format_object_base::home() {
423 }
424
425 //===----------------------------------------------------------------------===//
426 // raw_fd_ostream
427 //===----------------------------------------------------------------------===//
428
429 /// raw_fd_ostream - Open the specified file for writing. If an error
430 /// occurs, information about the error is put into ErrorInfo, and the
431 /// stream should be immediately destroyed; the string will be empty
432 /// if no error occurred.
raw_fd_ostream(const char * Filename,std::string & ErrorInfo,sys::fs::OpenFlags Flags)433 raw_fd_ostream::raw_fd_ostream(const char *Filename, std::string &ErrorInfo,
434 sys::fs::OpenFlags Flags)
435 : Error(false), UseAtomicWrites(false), pos(0) {
436 assert(Filename && "Filename is null");
437 ErrorInfo.clear();
438
439 // Handle "-" as stdout. Note that when we do this, we consider ourself
440 // the owner of stdout. This means that we can do things like close the
441 // file descriptor when we're done and set the "binary" flag globally.
442 if (Filename[0] == '-' && Filename[1] == 0) {
443 FD = STDOUT_FILENO;
444 // If user requested binary then put stdout into binary mode if
445 // possible.
446 if (!(Flags & sys::fs::F_Text))
447 sys::ChangeStdoutToBinary();
448 // Close stdout when we're done, to detect any output errors.
449 ShouldClose = true;
450 return;
451 }
452
453 std::error_code EC = sys::fs::openFileForWrite(Filename, FD, Flags);
454
455 if (EC) {
456 ErrorInfo = "Error opening output file '" + std::string(Filename) + "': " +
457 EC.message();
458 ShouldClose = false;
459 return;
460 }
461
462 // Ok, we successfully opened the file, so it'll need to be closed.
463 ShouldClose = true;
464 }
465
466 /// raw_fd_ostream ctor - FD is the file descriptor that this writes to. If
467 /// ShouldClose is true, this closes the file when the stream is destroyed.
raw_fd_ostream(int fd,bool shouldClose,bool unbuffered)468 raw_fd_ostream::raw_fd_ostream(int fd, bool shouldClose, bool unbuffered)
469 : raw_ostream(unbuffered), FD(fd),
470 ShouldClose(shouldClose), Error(false), UseAtomicWrites(false) {
471 #ifdef O_BINARY
472 // Setting STDOUT to binary mode is necessary in Win32
473 // to avoid undesirable linefeed conversion.
474 // Don't touch STDERR, or w*printf() (in assert()) would barf wide chars.
475 if (fd == STDOUT_FILENO)
476 setmode(fd, O_BINARY);
477 #endif
478
479 // Get the starting position.
480 off_t loc = ::lseek(FD, 0, SEEK_CUR);
481 if (loc == (off_t)-1)
482 pos = 0;
483 else
484 pos = static_cast<uint64_t>(loc);
485 }
486
~raw_fd_ostream()487 raw_fd_ostream::~raw_fd_ostream() {
488 if (FD >= 0) {
489 flush();
490 if (ShouldClose)
491 while (::close(FD) != 0)
492 if (errno != EINTR) {
493 error_detected();
494 break;
495 }
496 }
497
498 #ifdef __MINGW32__
499 // On mingw, global dtors should not call exit().
500 // report_fatal_error() invokes exit(). We know report_fatal_error()
501 // might not write messages to stderr when any errors were detected
502 // on FD == 2.
503 if (FD == 2) return;
504 #endif
505
506 // If there are any pending errors, report them now. Clients wishing
507 // to avoid report_fatal_error calls should check for errors with
508 // has_error() and clear the error flag with clear_error() before
509 // destructing raw_ostream objects which may have errors.
510 if (has_error())
511 report_fatal_error("IO failure on output stream.", /*GenCrashDiag=*/false);
512 }
513
514
write_impl(const char * Ptr,size_t Size)515 void raw_fd_ostream::write_impl(const char *Ptr, size_t Size) {
516 assert(FD >= 0 && "File already closed.");
517 pos += Size;
518
519 do {
520 ssize_t ret;
521
522 // Check whether we should attempt to use atomic writes.
523 if (LLVM_LIKELY(!UseAtomicWrites)) {
524 ret = ::write(FD, Ptr, Size);
525 } else {
526 // Use ::writev() where available.
527 #if defined(HAVE_WRITEV)
528 const void *Addr = static_cast<const void *>(Ptr);
529 struct iovec IOV = {const_cast<void *>(Addr), Size };
530 ret = ::writev(FD, &IOV, 1);
531 #else
532 ret = ::write(FD, Ptr, Size);
533 #endif
534 }
535
536 if (ret < 0) {
537 // If it's a recoverable error, swallow it and retry the write.
538 //
539 // Ideally we wouldn't ever see EAGAIN or EWOULDBLOCK here, since
540 // raw_ostream isn't designed to do non-blocking I/O. However, some
541 // programs, such as old versions of bjam, have mistakenly used
542 // O_NONBLOCK. For compatibility, emulate blocking semantics by
543 // spinning until the write succeeds. If you don't want spinning,
544 // don't use O_NONBLOCK file descriptors with raw_ostream.
545 if (errno == EINTR || errno == EAGAIN
546 #ifdef EWOULDBLOCK
547 || errno == EWOULDBLOCK
548 #endif
549 )
550 continue;
551
552 // Otherwise it's a non-recoverable error. Note it and quit.
553 error_detected();
554 break;
555 }
556
557 // The write may have written some or all of the data. Update the
558 // size and buffer pointer to reflect the remainder that needs
559 // to be written. If there are no bytes left, we're done.
560 Ptr += ret;
561 Size -= ret;
562 } while (Size > 0);
563 }
564
close()565 void raw_fd_ostream::close() {
566 assert(ShouldClose);
567 ShouldClose = false;
568 flush();
569 while (::close(FD) != 0)
570 if (errno != EINTR) {
571 error_detected();
572 break;
573 }
574 FD = -1;
575 }
576
seek(uint64_t off)577 uint64_t raw_fd_ostream::seek(uint64_t off) {
578 flush();
579 pos = ::lseek(FD, off, SEEK_SET);
580 if (pos != off)
581 error_detected();
582 return pos;
583 }
584
preferred_buffer_size() const585 size_t raw_fd_ostream::preferred_buffer_size() const {
586 #if !defined(_MSC_VER) && !defined(__MINGW32__) && !defined(__minix)
587 // Windows and Minix have no st_blksize.
588 assert(FD >= 0 && "File not yet open!");
589 struct stat statbuf;
590 if (fstat(FD, &statbuf) != 0)
591 return 0;
592
593 // If this is a terminal, don't use buffering. Line buffering
594 // would be a more traditional thing to do, but it's not worth
595 // the complexity.
596 if (S_ISCHR(statbuf.st_mode) && isatty(FD))
597 return 0;
598 // Return the preferred block size.
599 return statbuf.st_blksize;
600 #else
601 return raw_ostream::preferred_buffer_size();
602 #endif
603 }
604
changeColor(enum Colors colors,bool bold,bool bg)605 raw_ostream &raw_fd_ostream::changeColor(enum Colors colors, bool bold,
606 bool bg) {
607 if (sys::Process::ColorNeedsFlush())
608 flush();
609 const char *colorcode =
610 (colors == SAVEDCOLOR) ? sys::Process::OutputBold(bg)
611 : sys::Process::OutputColor(colors, bold, bg);
612 if (colorcode) {
613 size_t len = strlen(colorcode);
614 write(colorcode, len);
615 // don't account colors towards output characters
616 pos -= len;
617 }
618 return *this;
619 }
620
resetColor()621 raw_ostream &raw_fd_ostream::resetColor() {
622 if (sys::Process::ColorNeedsFlush())
623 flush();
624 const char *colorcode = sys::Process::ResetColor();
625 if (colorcode) {
626 size_t len = strlen(colorcode);
627 write(colorcode, len);
628 // don't account colors towards output characters
629 pos -= len;
630 }
631 return *this;
632 }
633
reverseColor()634 raw_ostream &raw_fd_ostream::reverseColor() {
635 if (sys::Process::ColorNeedsFlush())
636 flush();
637 const char *colorcode = sys::Process::OutputReverse();
638 if (colorcode) {
639 size_t len = strlen(colorcode);
640 write(colorcode, len);
641 // don't account colors towards output characters
642 pos -= len;
643 }
644 return *this;
645 }
646
is_displayed() const647 bool raw_fd_ostream::is_displayed() const {
648 return sys::Process::FileDescriptorIsDisplayed(FD);
649 }
650
has_colors() const651 bool raw_fd_ostream::has_colors() const {
652 return sys::Process::FileDescriptorHasColors(FD);
653 }
654
655 //===----------------------------------------------------------------------===//
656 // outs(), errs(), nulls()
657 //===----------------------------------------------------------------------===//
658
659 /// outs() - This returns a reference to a raw_ostream for standard output.
660 /// Use it like: outs() << "foo" << "bar";
outs()661 raw_ostream &llvm::outs() {
662 // Set buffer settings to model stdout behavior.
663 // Delete the file descriptor when the program exists, forcing error
664 // detection. If you don't want this behavior, don't use outs().
665 static raw_fd_ostream S(STDOUT_FILENO, true);
666 return S;
667 }
668
669 /// errs() - This returns a reference to a raw_ostream for standard error.
670 /// Use it like: errs() << "foo" << "bar";
errs()671 raw_ostream &llvm::errs() {
672 // Set standard error to be unbuffered by default.
673 static raw_fd_ostream S(STDERR_FILENO, false, true);
674 return S;
675 }
676
677 /// nulls() - This returns a reference to a raw_ostream which discards output.
nulls()678 raw_ostream &llvm::nulls() {
679 static raw_null_ostream S;
680 return S;
681 }
682
683
684 //===----------------------------------------------------------------------===//
685 // raw_string_ostream
686 //===----------------------------------------------------------------------===//
687
~raw_string_ostream()688 raw_string_ostream::~raw_string_ostream() {
689 flush();
690 }
691
write_impl(const char * Ptr,size_t Size)692 void raw_string_ostream::write_impl(const char *Ptr, size_t Size) {
693 OS.append(Ptr, Size);
694 }
695
696 //===----------------------------------------------------------------------===//
697 // raw_svector_ostream
698 //===----------------------------------------------------------------------===//
699
700 // The raw_svector_ostream implementation uses the SmallVector itself as the
701 // buffer for the raw_ostream. We guarantee that the raw_ostream buffer is
702 // always pointing past the end of the vector, but within the vector
703 // capacity. This allows raw_ostream to write directly into the correct place,
704 // and we only need to set the vector size when the data is flushed.
705
raw_svector_ostream(SmallVectorImpl<char> & O)706 raw_svector_ostream::raw_svector_ostream(SmallVectorImpl<char> &O) : OS(O) {
707 // Set up the initial external buffer. We make sure that the buffer has at
708 // least 128 bytes free; raw_ostream itself only requires 64, but we want to
709 // make sure that we don't grow the buffer unnecessarily on destruction (when
710 // the data is flushed). See the FIXME below.
711 OS.reserve(OS.size() + 128);
712 SetBuffer(OS.end(), OS.capacity() - OS.size());
713 }
714
~raw_svector_ostream()715 raw_svector_ostream::~raw_svector_ostream() {
716 // FIXME: Prevent resizing during this flush().
717 flush();
718 }
719
720 /// resync - This is called when the SmallVector we're appending to is changed
721 /// outside of the raw_svector_ostream's control. It is only safe to do this
722 /// if the raw_svector_ostream has previously been flushed.
resync()723 void raw_svector_ostream::resync() {
724 assert(GetNumBytesInBuffer() == 0 && "Didn't flush before mutating vector");
725
726 if (OS.capacity() - OS.size() < 64)
727 OS.reserve(OS.capacity() * 2);
728 SetBuffer(OS.end(), OS.capacity() - OS.size());
729 }
730
write_impl(const char * Ptr,size_t Size)731 void raw_svector_ostream::write_impl(const char *Ptr, size_t Size) {
732 // If we're writing bytes from the end of the buffer into the smallvector, we
733 // don't need to copy the bytes, just commit the bytes because they are
734 // already in the right place.
735 if (Ptr == OS.end()) {
736 assert(OS.size() + Size <= OS.capacity() && "Invalid write_impl() call!");
737 OS.set_size(OS.size() + Size);
738 } else {
739 assert(GetNumBytesInBuffer() == 0 &&
740 "Should be writing from buffer if some bytes in it");
741 // Otherwise, do copy the bytes.
742 OS.append(Ptr, Ptr+Size);
743 }
744
745 // Grow the vector if necessary.
746 if (OS.capacity() - OS.size() < 64)
747 OS.reserve(OS.capacity() * 2);
748
749 // Update the buffer position.
750 SetBuffer(OS.end(), OS.capacity() - OS.size());
751 }
752
current_pos() const753 uint64_t raw_svector_ostream::current_pos() const {
754 return OS.size();
755 }
756
str()757 StringRef raw_svector_ostream::str() {
758 flush();
759 return StringRef(OS.begin(), OS.size());
760 }
761
762 //===----------------------------------------------------------------------===//
763 // raw_null_ostream
764 //===----------------------------------------------------------------------===//
765
~raw_null_ostream()766 raw_null_ostream::~raw_null_ostream() {
767 #ifndef NDEBUG
768 // ~raw_ostream asserts that the buffer is empty. This isn't necessary
769 // with raw_null_ostream, but it's better to have raw_null_ostream follow
770 // the rules than to change the rules just for raw_null_ostream.
771 flush();
772 #endif
773 }
774
write_impl(const char * Ptr,size_t Size)775 void raw_null_ostream::write_impl(const char *Ptr, size_t Size) {
776 }
777
current_pos() const778 uint64_t raw_null_ostream::current_pos() const {
779 return 0;
780 }
781