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 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. 72 void raw_ostream::handle() {} 73 74 size_t raw_ostream::preferred_buffer_size() const { 75 // BUFSIZ is intended to be a reasonable default. 76 return BUFSIZ; 77 } 78 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 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 } 106 107 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 } 122 123 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 } 132 133 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 } 148 149 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 } 158 159 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 } 176 177 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 } 218 219 raw_ostream &raw_ostream::operator<<(const void *P) { 220 *this << '0' << 'x'; 221 222 return write_hex((uintptr_t) P); 223 } 224 225 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 } 265 266 267 268 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 } 274 275 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 } 294 295 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 } 336 337 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. 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. 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. 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. 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. 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 } 486 487 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 } 513 514 515 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 } 564 565 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 } 576 577 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 } 584 585 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 } 604 605 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 } 620 621 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 } 633 634 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 } 646 647 bool raw_fd_ostream::is_displayed() const { 648 return sys::Process::FileDescriptorIsDisplayed(FD); 649 } 650 651 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"; 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"; 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. 678 raw_ostream &llvm::nulls() { 679 static raw_null_ostream S; 680 return S; 681 } 682 683 684 //===----------------------------------------------------------------------===// 685 // raw_string_ostream 686 //===----------------------------------------------------------------------===// 687 688 raw_string_ostream::~raw_string_ostream() { 689 flush(); 690 } 691 692 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. 705 706 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 } 714 715 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. 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 } 730 731 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 } 752 753 uint64_t raw_svector_ostream::current_pos() const { 754 return OS.size(); 755 } 756 757 StringRef raw_svector_ostream::str() { 758 flush(); 759 return StringRef(OS.begin(), OS.size()); 760 } 761 762 //===----------------------------------------------------------------------===// 763 // raw_null_ostream 764 //===----------------------------------------------------------------------===// 765 766 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 } 774 775 void raw_null_ostream::write_impl(const char *Ptr, size_t Size) { 776 } 777 778 uint64_t raw_null_ostream::current_pos() const { 779 return 0; 780 } 781