raw_ostream.cpp revision 218893
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/Support/Format.h" 16#include "llvm/Support/Program.h" 17#include "llvm/Support/Process.h" 18#include "llvm/ADT/StringExtras.h" 19#include "llvm/ADT/SmallVector.h" 20#include "llvm/Config/config.h" 21#include "llvm/Support/Compiler.h" 22#include "llvm/Support/ErrorHandling.h" 23#include "llvm/ADT/STLExtras.h" 24#include <cctype> 25#include <cerrno> 26#include <sys/stat.h> 27#include <sys/types.h> 28 29#if defined(HAVE_UNISTD_H) 30# include <unistd.h> 31#endif 32#if defined(HAVE_FCNTL_H) 33# include <fcntl.h> 34#endif 35#if defined(HAVE_SYS_UIO_H) && defined(HAVE_WRITEV) 36# include <sys/uio.h> 37#endif 38 39#if defined(__CYGWIN__) 40#include <io.h> 41#endif 42 43#if defined(_MSC_VER) 44#include <io.h> 45#include <fcntl.h> 46#ifndef STDIN_FILENO 47# define STDIN_FILENO 0 48#endif 49#ifndef STDOUT_FILENO 50# define STDOUT_FILENO 1 51#endif 52#ifndef STDERR_FILENO 53# define STDERR_FILENO 2 54#endif 55#endif 56 57using namespace llvm; 58 59raw_ostream::~raw_ostream() { 60 // raw_ostream's subclasses should take care to flush the buffer 61 // in their destructors. 62 assert(OutBufCur == OutBufStart && 63 "raw_ostream destructor called with non-empty buffer!"); 64 65 if (BufferMode == InternalBuffer) 66 delete [] OutBufStart; 67} 68 69// An out of line virtual method to provide a home for the class vtable. 70void raw_ostream::handle() {} 71 72size_t raw_ostream::preferred_buffer_size() const { 73 // BUFSIZ is intended to be a reasonable default. 74 return BUFSIZ; 75} 76 77void raw_ostream::SetBuffered() { 78 // Ask the subclass to determine an appropriate buffer size. 79 if (size_t Size = preferred_buffer_size()) 80 SetBufferSize(Size); 81 else 82 // It may return 0, meaning this stream should be unbuffered. 83 SetUnbuffered(); 84} 85 86void raw_ostream::SetBufferAndMode(char *BufferStart, size_t Size, 87 BufferKind Mode) { 88 assert(((Mode == Unbuffered && BufferStart == 0 && Size == 0) || 89 (Mode != Unbuffered && BufferStart && Size)) && 90 "stream must be unbuffered or have at least one byte"); 91 // Make sure the current buffer is free of content (we can't flush here; the 92 // child buffer management logic will be in write_impl). 93 assert(GetNumBytesInBuffer() == 0 && "Current buffer is non-empty!"); 94 95 if (BufferMode == InternalBuffer) 96 delete [] OutBufStart; 97 OutBufStart = BufferStart; 98 OutBufEnd = OutBufStart+Size; 99 OutBufCur = OutBufStart; 100 BufferMode = Mode; 101 102 assert(OutBufStart <= OutBufEnd && "Invalid size!"); 103} 104 105raw_ostream &raw_ostream::operator<<(unsigned long N) { 106 // Zero is a special case. 107 if (N == 0) 108 return *this << '0'; 109 110 char NumberBuffer[20]; 111 char *EndPtr = NumberBuffer+sizeof(NumberBuffer); 112 char *CurPtr = EndPtr; 113 114 while (N) { 115 *--CurPtr = '0' + char(N % 10); 116 N /= 10; 117 } 118 return write(CurPtr, EndPtr-CurPtr); 119} 120 121raw_ostream &raw_ostream::operator<<(long N) { 122 if (N < 0) { 123 *this << '-'; 124 N = -N; 125 } 126 127 return this->operator<<(static_cast<unsigned long>(N)); 128} 129 130raw_ostream &raw_ostream::operator<<(unsigned long long N) { 131 // Output using 32-bit div/mod when possible. 132 if (N == static_cast<unsigned long>(N)) 133 return this->operator<<(static_cast<unsigned long>(N)); 134 135 char NumberBuffer[20]; 136 char *EndPtr = NumberBuffer+sizeof(NumberBuffer); 137 char *CurPtr = EndPtr; 138 139 while (N) { 140 *--CurPtr = '0' + char(N % 10); 141 N /= 10; 142 } 143 return write(CurPtr, EndPtr-CurPtr); 144} 145 146raw_ostream &raw_ostream::operator<<(long long N) { 147 if (N < 0) { 148 *this << '-'; 149 // Avoid undefined behavior on INT64_MIN with a cast. 150 N = -(unsigned long long)N; 151 } 152 153 return this->operator<<(static_cast<unsigned long long>(N)); 154} 155 156raw_ostream &raw_ostream::write_hex(unsigned long long N) { 157 // Zero is a special case. 158 if (N == 0) 159 return *this << '0'; 160 161 char NumberBuffer[20]; 162 char *EndPtr = NumberBuffer+sizeof(NumberBuffer); 163 char *CurPtr = EndPtr; 164 165 while (N) { 166 uintptr_t x = N % 16; 167 *--CurPtr = (x < 10 ? '0' + x : 'a' + x - 10); 168 N /= 16; 169 } 170 171 return write(CurPtr, EndPtr-CurPtr); 172} 173 174raw_ostream &raw_ostream::write_escaped(StringRef Str, 175 bool UseHexEscapes) { 176 for (unsigned i = 0, e = Str.size(); i != e; ++i) { 177 unsigned char c = Str[i]; 178 179 switch (c) { 180 case '\\': 181 *this << '\\' << '\\'; 182 break; 183 case '\t': 184 *this << '\\' << 't'; 185 break; 186 case '\n': 187 *this << '\\' << 'n'; 188 break; 189 case '"': 190 *this << '\\' << '"'; 191 break; 192 default: 193 if (std::isprint(c)) { 194 *this << c; 195 break; 196 } 197 198 // Write out the escaped representation. 199 if (UseHexEscapes) { 200 *this << '\\' << 'x'; 201 *this << hexdigit((c >> 4 & 0xF)); 202 *this << hexdigit((c >> 0) & 0xF); 203 } else { 204 // Always use a full 3-character octal escape. 205 *this << '\\'; 206 *this << char('0' + ((c >> 6) & 7)); 207 *this << char('0' + ((c >> 3) & 7)); 208 *this << char('0' + ((c >> 0) & 7)); 209 } 210 } 211 } 212 213 return *this; 214} 215 216raw_ostream &raw_ostream::operator<<(const void *P) { 217 *this << '0' << 'x'; 218 219 return write_hex((uintptr_t) P); 220} 221 222raw_ostream &raw_ostream::operator<<(double N) { 223 return this->operator<<(format("%e", N)); 224} 225 226 227 228void raw_ostream::flush_nonempty() { 229 assert(OutBufCur > OutBufStart && "Invalid call to flush_nonempty."); 230 size_t Length = OutBufCur - OutBufStart; 231 OutBufCur = OutBufStart; 232 write_impl(OutBufStart, Length); 233} 234 235raw_ostream &raw_ostream::write(unsigned char C) { 236 // Group exceptional cases into a single branch. 237 if (BUILTIN_EXPECT(OutBufCur >= OutBufEnd, false)) { 238 if (BUILTIN_EXPECT(!OutBufStart, false)) { 239 if (BufferMode == Unbuffered) { 240 write_impl(reinterpret_cast<char*>(&C), 1); 241 return *this; 242 } 243 // Set up a buffer and start over. 244 SetBuffered(); 245 return write(C); 246 } 247 248 flush_nonempty(); 249 } 250 251 *OutBufCur++ = C; 252 return *this; 253} 254 255raw_ostream &raw_ostream::write(const char *Ptr, size_t Size) { 256 // Group exceptional cases into a single branch. 257 if (BUILTIN_EXPECT(OutBufCur+Size > OutBufEnd, false)) { 258 if (BUILTIN_EXPECT(!OutBufStart, false)) { 259 if (BufferMode == Unbuffered) { 260 write_impl(Ptr, Size); 261 return *this; 262 } 263 // Set up a buffer and start over. 264 SetBuffered(); 265 return write(Ptr, Size); 266 } 267 268 // Write out the data in buffer-sized blocks until the remainder 269 // fits within the buffer. 270 do { 271 size_t NumBytes = OutBufEnd - OutBufCur; 272 copy_to_buffer(Ptr, NumBytes); 273 flush_nonempty(); 274 Ptr += NumBytes; 275 Size -= NumBytes; 276 } while (OutBufCur+Size > OutBufEnd); 277 } 278 279 copy_to_buffer(Ptr, Size); 280 281 return *this; 282} 283 284void raw_ostream::copy_to_buffer(const char *Ptr, size_t Size) { 285 assert(Size <= size_t(OutBufEnd - OutBufCur) && "Buffer overrun!"); 286 287 // Handle short strings specially, memcpy isn't very good at very short 288 // strings. 289 switch (Size) { 290 case 4: OutBufCur[3] = Ptr[3]; // FALL THROUGH 291 case 3: OutBufCur[2] = Ptr[2]; // FALL THROUGH 292 case 2: OutBufCur[1] = Ptr[1]; // FALL THROUGH 293 case 1: OutBufCur[0] = Ptr[0]; // FALL THROUGH 294 case 0: break; 295 default: 296 memcpy(OutBufCur, Ptr, Size); 297 break; 298 } 299 300 OutBufCur += Size; 301} 302 303// Formatted output. 304raw_ostream &raw_ostream::operator<<(const format_object_base &Fmt) { 305 // If we have more than a few bytes left in our output buffer, try 306 // formatting directly onto its end. 307 size_t NextBufferSize = 127; 308 size_t BufferBytesLeft = OutBufEnd - OutBufCur; 309 if (BufferBytesLeft > 3) { 310 size_t BytesUsed = Fmt.print(OutBufCur, BufferBytesLeft); 311 312 // Common case is that we have plenty of space. 313 if (BytesUsed <= BufferBytesLeft) { 314 OutBufCur += BytesUsed; 315 return *this; 316 } 317 318 // Otherwise, we overflowed and the return value tells us the size to try 319 // again with. 320 NextBufferSize = BytesUsed; 321 } 322 323 // If we got here, we didn't have enough space in the output buffer for the 324 // string. Try printing into a SmallVector that is resized to have enough 325 // space. Iterate until we win. 326 SmallVector<char, 128> V; 327 328 while (1) { 329 V.resize(NextBufferSize); 330 331 // Try formatting into the SmallVector. 332 size_t BytesUsed = Fmt.print(V.data(), NextBufferSize); 333 334 // If BytesUsed fit into the vector, we win. 335 if (BytesUsed <= NextBufferSize) 336 return write(V.data(), BytesUsed); 337 338 // Otherwise, try again with a new size. 339 assert(BytesUsed > NextBufferSize && "Didn't grow buffer!?"); 340 NextBufferSize = BytesUsed; 341 } 342} 343 344/// indent - Insert 'NumSpaces' spaces. 345raw_ostream &raw_ostream::indent(unsigned NumSpaces) { 346 static const char Spaces[] = " " 347 " " 348 " "; 349 350 // Usually the indentation is small, handle it with a fastpath. 351 if (NumSpaces < array_lengthof(Spaces)) 352 return write(Spaces, NumSpaces); 353 354 while (NumSpaces) { 355 unsigned NumToWrite = std::min(NumSpaces, 356 (unsigned)array_lengthof(Spaces)-1); 357 write(Spaces, NumToWrite); 358 NumSpaces -= NumToWrite; 359 } 360 return *this; 361} 362 363 364//===----------------------------------------------------------------------===// 365// Formatted Output 366//===----------------------------------------------------------------------===// 367 368// Out of line virtual method. 369void format_object_base::home() { 370} 371 372//===----------------------------------------------------------------------===// 373// raw_fd_ostream 374//===----------------------------------------------------------------------===// 375 376/// raw_fd_ostream - Open the specified file for writing. If an error 377/// occurs, information about the error is put into ErrorInfo, and the 378/// stream should be immediately destroyed; the string will be empty 379/// if no error occurred. 380raw_fd_ostream::raw_fd_ostream(const char *Filename, std::string &ErrorInfo, 381 unsigned Flags) 382 : Error(false), UseAtomicWrites(false), pos(0) 383{ 384 assert(Filename != 0 && "Filename is null"); 385 // Verify that we don't have both "append" and "excl". 386 assert((!(Flags & F_Excl) || !(Flags & F_Append)) && 387 "Cannot specify both 'excl' and 'append' file creation flags!"); 388 389 ErrorInfo.clear(); 390 391 // Handle "-" as stdout. Note that when we do this, we consider ourself 392 // the owner of stdout. This means that we can do things like close the 393 // file descriptor when we're done and set the "binary" flag globally. 394 if (Filename[0] == '-' && Filename[1] == 0) { 395 FD = STDOUT_FILENO; 396 // If user requested binary then put stdout into binary mode if 397 // possible. 398 if (Flags & F_Binary) 399 sys::Program::ChangeStdoutToBinary(); 400 // Close stdout when we're done, to detect any output errors. 401 ShouldClose = true; 402 return; 403 } 404 405 int OpenFlags = O_WRONLY|O_CREAT; 406#ifdef O_BINARY 407 if (Flags & F_Binary) 408 OpenFlags |= O_BINARY; 409#endif 410 411 if (Flags & F_Append) 412 OpenFlags |= O_APPEND; 413 else 414 OpenFlags |= O_TRUNC; 415 if (Flags & F_Excl) 416 OpenFlags |= O_EXCL; 417 418 while ((FD = open(Filename, OpenFlags, 0664)) < 0) { 419 if (errno != EINTR) { 420 ErrorInfo = "Error opening output file '" + std::string(Filename) + "'"; 421 ShouldClose = false; 422 return; 423 } 424 } 425 426 // Ok, we successfully opened the file, so it'll need to be closed. 427 ShouldClose = true; 428} 429 430/// raw_fd_ostream ctor - FD is the file descriptor that this writes to. If 431/// ShouldClose is true, this closes the file when the stream is destroyed. 432raw_fd_ostream::raw_fd_ostream(int fd, bool shouldClose, bool unbuffered) 433 : raw_ostream(unbuffered), FD(fd), 434 ShouldClose(shouldClose), Error(false), UseAtomicWrites(false) { 435#ifdef O_BINARY 436 // Setting STDOUT and STDERR to binary mode is necessary in Win32 437 // to avoid undesirable linefeed conversion. 438 if (fd == STDOUT_FILENO || fd == STDERR_FILENO) 439 setmode(fd, O_BINARY); 440#endif 441 442 // Get the starting position. 443 off_t loc = ::lseek(FD, 0, SEEK_CUR); 444 if (loc == (off_t)-1) 445 pos = 0; 446 else 447 pos = static_cast<uint64_t>(loc); 448} 449 450raw_fd_ostream::~raw_fd_ostream() { 451 if (FD >= 0) { 452 flush(); 453 if (ShouldClose) 454 while (::close(FD) != 0) 455 if (errno != EINTR) { 456 error_detected(); 457 break; 458 } 459 } 460 461 // If there are any pending errors, report them now. Clients wishing 462 // to avoid report_fatal_error calls should check for errors with 463 // has_error() and clear the error flag with clear_error() before 464 // destructing raw_ostream objects which may have errors. 465 if (has_error()) 466 report_fatal_error("IO failure on output stream."); 467} 468 469 470void raw_fd_ostream::write_impl(const char *Ptr, size_t Size) { 471 assert(FD >= 0 && "File already closed."); 472 pos += Size; 473 474 do { 475 ssize_t ret; 476 477 // Check whether we should attempt to use atomic writes. 478 if (BUILTIN_EXPECT(!UseAtomicWrites, true)) { 479 ret = ::write(FD, Ptr, Size); 480 } else { 481 // Use ::writev() where available. 482#if defined(HAVE_WRITEV) 483 struct iovec IOV = { (void*) Ptr, Size }; 484 ret = ::writev(FD, &IOV, 1); 485#else 486 ret = ::write(FD, Ptr, Size); 487#endif 488 } 489 490 if (ret < 0) { 491 // If it's a recoverable error, swallow it and retry the write. 492 // 493 // Ideally we wouldn't ever see EAGAIN or EWOULDBLOCK here, since 494 // raw_ostream isn't designed to do non-blocking I/O. However, some 495 // programs, such as old versions of bjam, have mistakenly used 496 // O_NONBLOCK. For compatibility, emulate blocking semantics by 497 // spinning until the write succeeds. If you don't want spinning, 498 // don't use O_NONBLOCK file descriptors with raw_ostream. 499 if (errno == EINTR || errno == EAGAIN 500#ifdef EWOULDBLOCK 501 || errno == EWOULDBLOCK 502#endif 503 ) 504 continue; 505 506 // Otherwise it's a non-recoverable error. Note it and quit. 507 error_detected(); 508 break; 509 } 510 511 // The write may have written some or all of the data. Update the 512 // size and buffer pointer to reflect the remainder that needs 513 // to be written. If there are no bytes left, we're done. 514 Ptr += ret; 515 Size -= ret; 516 } while (Size > 0); 517} 518 519void raw_fd_ostream::close() { 520 assert(ShouldClose); 521 ShouldClose = false; 522 flush(); 523 while (::close(FD) != 0) 524 if (errno != EINTR) { 525 error_detected(); 526 break; 527 } 528 FD = -1; 529} 530 531uint64_t raw_fd_ostream::seek(uint64_t off) { 532 flush(); 533 pos = ::lseek(FD, off, SEEK_SET); 534 if (pos != off) 535 error_detected(); 536 return pos; 537} 538 539size_t raw_fd_ostream::preferred_buffer_size() const { 540#if !defined(_MSC_VER) && !defined(__MINGW32__) && !defined(__minix) 541 // Windows and Minix have no st_blksize. 542 assert(FD >= 0 && "File not yet open!"); 543 struct stat statbuf; 544 if (fstat(FD, &statbuf) != 0) 545 return 0; 546 547 // If this is a terminal, don't use buffering. Line buffering 548 // would be a more traditional thing to do, but it's not worth 549 // the complexity. 550 if (S_ISCHR(statbuf.st_mode) && isatty(FD)) 551 return 0; 552 // Return the preferred block size. 553 return statbuf.st_blksize; 554#else 555 return raw_ostream::preferred_buffer_size(); 556#endif 557} 558 559raw_ostream &raw_fd_ostream::changeColor(enum Colors colors, bool bold, 560 bool bg) { 561 if (sys::Process::ColorNeedsFlush()) 562 flush(); 563 const char *colorcode = 564 (colors == SAVEDCOLOR) ? sys::Process::OutputBold(bg) 565 : sys::Process::OutputColor(colors, bold, bg); 566 if (colorcode) { 567 size_t len = strlen(colorcode); 568 write(colorcode, len); 569 // don't account colors towards output characters 570 pos -= len; 571 } 572 return *this; 573} 574 575raw_ostream &raw_fd_ostream::resetColor() { 576 if (sys::Process::ColorNeedsFlush()) 577 flush(); 578 const char *colorcode = sys::Process::ResetColor(); 579 if (colorcode) { 580 size_t len = strlen(colorcode); 581 write(colorcode, len); 582 // don't account colors towards output characters 583 pos -= len; 584 } 585 return *this; 586} 587 588bool raw_fd_ostream::is_displayed() const { 589 return sys::Process::FileDescriptorIsDisplayed(FD); 590} 591 592//===----------------------------------------------------------------------===// 593// outs(), errs(), nulls() 594//===----------------------------------------------------------------------===// 595 596/// outs() - This returns a reference to a raw_ostream for standard output. 597/// Use it like: outs() << "foo" << "bar"; 598raw_ostream &llvm::outs() { 599 // Set buffer settings to model stdout behavior. 600 // Delete the file descriptor when the program exists, forcing error 601 // detection. If you don't want this behavior, don't use outs(). 602 static raw_fd_ostream S(STDOUT_FILENO, true); 603 return S; 604} 605 606/// errs() - This returns a reference to a raw_ostream for standard error. 607/// Use it like: errs() << "foo" << "bar"; 608raw_ostream &llvm::errs() { 609 // Set standard error to be unbuffered by default. 610 static raw_fd_ostream S(STDERR_FILENO, false, true); 611 return S; 612} 613 614/// nulls() - This returns a reference to a raw_ostream which discards output. 615raw_ostream &llvm::nulls() { 616 static raw_null_ostream S; 617 return S; 618} 619 620 621//===----------------------------------------------------------------------===// 622// raw_string_ostream 623//===----------------------------------------------------------------------===// 624 625raw_string_ostream::~raw_string_ostream() { 626 flush(); 627} 628 629void raw_string_ostream::write_impl(const char *Ptr, size_t Size) { 630 OS.append(Ptr, Size); 631} 632 633//===----------------------------------------------------------------------===// 634// raw_svector_ostream 635//===----------------------------------------------------------------------===// 636 637// The raw_svector_ostream implementation uses the SmallVector itself as the 638// buffer for the raw_ostream. We guarantee that the raw_ostream buffer is 639// always pointing past the end of the vector, but within the vector 640// capacity. This allows raw_ostream to write directly into the correct place, 641// and we only need to set the vector size when the data is flushed. 642 643raw_svector_ostream::raw_svector_ostream(SmallVectorImpl<char> &O) : OS(O) { 644 // Set up the initial external buffer. We make sure that the buffer has at 645 // least 128 bytes free; raw_ostream itself only requires 64, but we want to 646 // make sure that we don't grow the buffer unnecessarily on destruction (when 647 // the data is flushed). See the FIXME below. 648 OS.reserve(OS.size() + 128); 649 SetBuffer(OS.end(), OS.capacity() - OS.size()); 650} 651 652raw_svector_ostream::~raw_svector_ostream() { 653 // FIXME: Prevent resizing during this flush(). 654 flush(); 655} 656 657/// resync - This is called when the SmallVector we're appending to is changed 658/// outside of the raw_svector_ostream's control. It is only safe to do this 659/// if the raw_svector_ostream has previously been flushed. 660void raw_svector_ostream::resync() { 661 assert(GetNumBytesInBuffer() == 0 && "Didn't flush before mutating vector"); 662 663 if (OS.capacity() - OS.size() < 64) 664 OS.reserve(OS.capacity() * 2); 665 SetBuffer(OS.end(), OS.capacity() - OS.size()); 666} 667 668void raw_svector_ostream::write_impl(const char *Ptr, size_t Size) { 669 // If we're writing bytes from the end of the buffer into the smallvector, we 670 // don't need to copy the bytes, just commit the bytes because they are 671 // already in the right place. 672 if (Ptr == OS.end()) { 673 assert(OS.size() + Size <= OS.capacity() && "Invalid write_impl() call!"); 674 OS.set_size(OS.size() + Size); 675 } else { 676 assert(GetNumBytesInBuffer() == 0 && 677 "Should be writing from buffer if some bytes in it"); 678 // Otherwise, do copy the bytes. 679 OS.append(Ptr, Ptr+Size); 680 } 681 682 // Grow the vector if necessary. 683 if (OS.capacity() - OS.size() < 64) 684 OS.reserve(OS.capacity() * 2); 685 686 // Update the buffer position. 687 SetBuffer(OS.end(), OS.capacity() - OS.size()); 688} 689 690uint64_t raw_svector_ostream::current_pos() const { 691 return OS.size(); 692} 693 694StringRef raw_svector_ostream::str() { 695 flush(); 696 return StringRef(OS.begin(), OS.size()); 697} 698 699//===----------------------------------------------------------------------===// 700// raw_null_ostream 701//===----------------------------------------------------------------------===// 702 703raw_null_ostream::~raw_null_ostream() { 704#ifndef NDEBUG 705 // ~raw_ostream asserts that the buffer is empty. This isn't necessary 706 // with raw_null_ostream, but it's better to have raw_null_ostream follow 707 // the rules than to change the rules just for raw_null_ostream. 708 flush(); 709#endif 710} 711 712void raw_null_ostream::write_impl(const char *Ptr, size_t Size) { 713} 714 715uint64_t raw_null_ostream::current_pos() const { 716 return 0; 717} 718