1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
|
//===--- raw_ostream.cpp - Implement the raw_ostream classes --------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This implements support for bulk buffered stream output.
//
//===----------------------------------------------------------------------===//
#include "llvm/Support/raw_ostream.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/Config/config.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/Format.h"
#include "llvm/Support/Process.h"
#include "llvm/Support/Program.h"
#include <cctype>
#include <cerrno>
#include <sys/stat.h>
#include <system_error>
// <fcntl.h> may provide O_BINARY.
#if defined(HAVE_FCNTL_H)
# include <fcntl.h>
#endif
#if defined(HAVE_UNISTD_H)
# include <unistd.h>
#endif
#if defined(HAVE_SYS_UIO_H) && defined(HAVE_WRITEV)
# include <sys/uio.h>
#endif
#if defined(__CYGWIN__)
#include <io.h>
#endif
#if defined(_MSC_VER)
#include <io.h>
#ifndef STDIN_FILENO
# define STDIN_FILENO 0
#endif
#ifndef STDOUT_FILENO
# define STDOUT_FILENO 1
#endif
#ifndef STDERR_FILENO
# define STDERR_FILENO 2
#endif
#endif
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;
}
// 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 && Size == 0) ||
(Mode != Unbuffered && BufferStart && Size != 0)) &&
"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;
}
return write(CurPtr, EndPtr-CurPtr);
}
raw_ostream &raw_ostream::operator<<(long N) {
if (N < 0) {
*this << '-';
// Avoid undefined behavior on LONG_MIN with a cast.
N = -(unsigned long)N;
}
return this->operator<<(static_cast<unsigned long>(N));
}
raw_ostream &raw_ostream::operator<<(unsigned long long N) {
// 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;
}
return write(CurPtr, EndPtr-CurPtr);
}
raw_ostream &raw_ostream::operator<<(long long N) {
if (N < 0) {
*this << '-';
// Avoid undefined behavior on INT64_MIN with a cast.
N = -(unsigned long long)N;
}
return this->operator<<(static_cast<unsigned long long>(N));
}
raw_ostream &raw_ostream::write_hex(unsigned long 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) {
uintptr_t x = N % 16;
*--CurPtr = (x < 10 ? '0' + x : 'a' + x - 10);
N /= 16;
}
return write(CurPtr, EndPtr-CurPtr);
}
raw_ostream &raw_ostream::write_escaped(StringRef Str,
bool UseHexEscapes) {
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;
}
// Write out the escaped representation.
if (UseHexEscapes) {
*this << '\\' << 'x';
*this << hexdigit((c >> 4 & 0xF));
*this << hexdigit((c >> 0) & 0xF);
} else {
// Always use a full 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) {
#ifdef _WIN32
// On MSVCRT and compatible, output of %e is incompatible to Posix
// by default. Number of exponent digits should be at least 2. "%+03d"
// FIXME: Implement our formatter to here or Support/Format.h!
#if __cplusplus >= 201103L && defined(__MINGW32__)
// FIXME: It should be generic to C++11.
if (N == 0.0 && std::signbit(N))
return *this << "-0.000000e+00";
#else
int fpcl = _fpclass(N);
// negative zero
if (fpcl == _FPCLASS_NZ)
return *this << "-0.000000e+00";
#endif
char buf[16];
unsigned len;
len = snprintf(buf, sizeof(buf), "%e", N);
if (len <= sizeof(buf) - 2) {
if (len >= 5 && buf[len - 5] == 'e' && buf[len - 3] == '0') {
int cs = buf[len - 4];
if (cs == '+' || cs == '-') {
int c1 = buf[len - 2];
int c0 = buf[len - 1];
if (isdigit(static_cast<unsigned char>(c1)) &&
isdigit(static_cast<unsigned char>(c0))) {
// Trim leading '0': "...e+012" -> "...e+12\0"
buf[len - 3] = c1;
buf[len - 2] = c0;
buf[--len] = 0;
}
}
}
return this->operator<<(buf);
}
#endif
return this->operator<<(format("%e", N));
}
void raw_ostream::flush_nonempty() {
assert(OutBufCur > OutBufStart && "Invalid call to flush_nonempty.");
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 (LLVM_UNLIKELY(OutBufCur >= OutBufEnd)) {
if (LLVM_UNLIKELY(!OutBufStart)) {
if (BufferMode == Unbuffered) {
write_impl(reinterpret_cast<char*>(&C), 1);
return *this;
}
// Set up a buffer and start over.
SetBuffered();
return write(C);
}
flush_nonempty();
}
*OutBufCur++ = C;
return *this;
}
raw_ostream &raw_ostream::write(const char *Ptr, size_t Size) {
// Group exceptional cases into a single branch.
if (LLVM_UNLIKELY(size_t(OutBufEnd - OutBufCur) < Size)) {
if (LLVM_UNLIKELY(!OutBufStart)) {
if (BufferMode == Unbuffered) {
write_impl(Ptr, Size);
return *this;
}
// Set up a buffer and start over.
SetBuffered();
return write(Ptr, Size);
}
size_t NumBytes = OutBufEnd - OutBufCur;
// If the buffer is empty at this point we have a string that is larger
// than the buffer. Directly write the chunk that is a multiple of the
// preferred buffer size and put the remainder in the buffer.
if (LLVM_UNLIKELY(OutBufCur == OutBufStart)) {
size_t BytesToWrite = Size - (Size % NumBytes);
write_impl(Ptr, BytesToWrite);
size_t BytesRemaining = Size - BytesToWrite;
if (BytesRemaining > size_t(OutBufEnd - OutBufCur)) {
// Too much left over to copy into our buffer.
return write(Ptr + BytesToWrite, BytesRemaining);
}
copy_to_buffer(Ptr + BytesToWrite, BytesRemaining);
return *this;
}
// We don't have enough space in the buffer to fit the string in. Insert as
// much as possible, flush and start over with the remainder.
copy_to_buffer(Ptr, NumBytes);
flush_nonempty();
return write(Ptr + NumBytes, Size - NumBytes);
}
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) {
case 4: OutBufCur[3] = Ptr[3]; // FALL THROUGH
case 3: OutBufCur[2] = Ptr[2]; // FALL THROUGH
case 2: OutBufCur[1] = Ptr[1]; // FALL THROUGH
case 1: OutBufCur[0] = Ptr[0]; // FALL THROUGH
case 0: break;
default:
memcpy(OutBufCur, Ptr, Size);
break;
}
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.
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) {
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.
size_t BytesUsed = Fmt.print(V.data(), NextBufferSize);
// If BytesUsed fit into the vector, we win.
if (BytesUsed <= NextBufferSize)
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
//===----------------------------------------------------------------------===//
// Out of line virtual method.
void format_object_base::home() {
}
//===----------------------------------------------------------------------===//
// raw_fd_ostream
//===----------------------------------------------------------------------===//
/// raw_fd_ostream - Open the specified file for writing. If an error
/// 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, std::string &ErrorInfo,
sys::fs::OpenFlags Flags)
: Error(false), UseAtomicWrites(false), pos(0) {
assert(Filename && "Filename is null");
ErrorInfo.clear();
// 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
// file descriptor when we're done and set the "binary" flag globally.
if (Filename[0] == '-' && Filename[1] == 0) {
FD = STDOUT_FILENO;
// If user requested binary then put stdout into binary mode if
// possible.
if (!(Flags & sys::fs::F_Text))
sys::ChangeStdoutToBinary();
// Close stdout when we're done, to detect any output errors.
ShouldClose = true;
return;
}
std::error_code EC = sys::fs::openFileForWrite(Filename, FD, Flags);
if (EC) {
ErrorInfo = "Error opening output file '" + std::string(Filename) + "': " +
EC.message();
ShouldClose = false;
return;
}
// Ok, we successfully opened the file, so it'll need to be closed.
ShouldClose = true;
}
/// 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) {
#ifdef O_BINARY
// Setting STDOUT to binary mode is necessary in Win32
// to avoid undesirable linefeed conversion.
// Don't touch STDERR, or w*printf() (in assert()) would barf wide chars.
if (fd == STDOUT_FILENO)
setmode(fd, O_BINARY);
#endif
// Get the starting position.
off_t loc = ::lseek(FD, 0, SEEK_CUR);
if (loc == (off_t)-1)
pos = 0;
else
pos = static_cast<uint64_t>(loc);
}
raw_fd_ostream::~raw_fd_ostream() {
if (FD >= 0) {
flush();
if (ShouldClose)
while (::close(FD) != 0)
if (errno != EINTR) {
error_detected();
break;
}
}
#ifdef __MINGW32__
// On mingw, global dtors should not call exit().
// report_fatal_error() invokes exit(). We know report_fatal_error()
// might not write messages to stderr when any errors were detected
// on FD == 2.
if (FD == 2) return;
#endif
// 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 (has_error())
report_fatal_error("IO failure on output stream.", /*GenCrashDiag=*/false);
}
void raw_fd_ostream::write_impl(const char *Ptr, size_t Size) {
assert(FD >= 0 && "File already closed.");
pos += Size;
do {
ssize_t ret;
// Check whether we should attempt to use atomic writes.
if (LLVM_LIKELY(!UseAtomicWrites)) {
ret = ::write(FD, Ptr, Size);
} else {
// Use ::writev() where available.
#if defined(HAVE_WRITEV)
const void *Addr = static_cast<const void *>(Ptr);
struct iovec IOV = {const_cast<void *>(Addr), Size };
ret = ::writev(FD, &IOV, 1);
#else
ret = ::write(FD, Ptr, Size);
#endif
}
if (ret < 0) {
// If it's a recoverable error, swallow it and retry the write.
//
// Ideally we wouldn't ever see EAGAIN or EWOULDBLOCK here, since
// raw_ostream isn't designed to do non-blocking I/O. However, some
// programs, such as old versions of bjam, have mistakenly used
// O_NONBLOCK. For compatibility, emulate blocking semantics by
// spinning until the write succeeds. If you don't want spinning,
// don't use O_NONBLOCK file descriptors with raw_ostream.
if (errno == EINTR || errno == EAGAIN
#ifdef EWOULDBLOCK
|| errno == EWOULDBLOCK
#endif
)
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);
ShouldClose = false;
flush();
while (::close(FD) != 0)
if (errno != EINTR) {
error_detected();
break;
}
FD = -1;
}
uint64_t raw_fd_ostream::seek(uint64_t off) {
flush();
pos = ::lseek(FD, off, SEEK_SET);
if (pos != off)
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;
#else
return raw_ostream::preferred_buffer_size();
#endif
}
raw_ostream &raw_fd_ostream::changeColor(enum Colors colors, bool bold,
bool bg) {
if (sys::Process::ColorNeedsFlush())
flush();
const char *colorcode =
(colors == SAVEDCOLOR) ? sys::Process::OutputBold(bg)
: sys::Process::OutputColor(colors, bold, bg);
if (colorcode) {
size_t len = strlen(colorcode);
write(colorcode, len);
// don't account colors towards output characters
pos -= len;
}
return *this;
}
raw_ostream &raw_fd_ostream::resetColor() {
if (sys::Process::ColorNeedsFlush())
flush();
const char *colorcode = sys::Process::ResetColor();
if (colorcode) {
size_t len = strlen(colorcode);
write(colorcode, len);
// don't account colors towards output characters
pos -= len;
}
return *this;
}
raw_ostream &raw_fd_ostream::reverseColor() {
if (sys::Process::ColorNeedsFlush())
flush();
const char *colorcode = sys::Process::OutputReverse();
if (colorcode) {
size_t len = strlen(colorcode);
write(colorcode, len);
// don't account colors towards output characters
pos -= len;
}
return *this;
}
bool raw_fd_ostream::is_displayed() const {
return sys::Process::FileDescriptorIsDisplayed(FD);
}
bool raw_fd_ostream::has_colors() const {
return sys::Process::FileDescriptorHasColors(FD);
}
//===----------------------------------------------------------------------===//
// outs(), errs(), nulls()
//===----------------------------------------------------------------------===//
/// outs() - This returns a reference to a raw_ostream for standard output.
/// Use it like: outs() << "foo" << "bar";
raw_ostream &llvm::outs() {
// Set buffer settings to model stdout behavior.
// Delete the file descriptor when the program exists, forcing error
// detection. If you don't want this behavior, don't use outs().
static raw_fd_ostream S(STDOUT_FILENO, true);
return S;
}
/// errs() - This returns a reference to a raw_ostream for standard error.
/// Use it like: errs() << "foo" << "bar";
raw_ostream &llvm::errs() {
// Set standard error to be unbuffered by default.
static raw_fd_ostream S(STDERR_FILENO, false, true);
return S;
}
/// nulls() - This returns a reference to a raw_ostream which discards output.
raw_ostream &llvm::nulls() {
static raw_null_ostream S;
return S;
}
//===----------------------------------------------------------------------===//
// raw_string_ostream
//===----------------------------------------------------------------------===//
raw_string_ostream::~raw_string_ostream() {
flush();
}
void raw_string_ostream::write_impl(const char *Ptr, size_t Size) {
OS.append(Ptr, 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());
}
//===----------------------------------------------------------------------===//
// 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
}
void raw_null_ostream::write_impl(const char *Ptr, size_t Size) {
}
uint64_t raw_null_ostream::current_pos() const {
return 0;
}
|