1 //===--- raw_ostream.cpp - Implement the raw_ostream classes --------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This implements support for bulk buffered stream output.
12 //===----------------------------------------------------------------------===//
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/FormatVariadic.h"
24 #include "llvm/Support/MathExtras.h"
25 #include "llvm/Support/NativeFormatting.h"
26 #include "llvm/Support/Process.h"
27 #include "llvm/Support/Program.h"
34 #include <system_error>
36 // <fcntl.h> may provide O_BINARY.
37 #if defined(HAVE_FCNTL_H)
41 #if defined(HAVE_UNISTD_H)
44 #if defined(HAVE_SYS_UIO_H) && defined(HAVE_WRITEV)
48 #if defined(__CYGWIN__)
55 # define STDIN_FILENO 0
58 # define STDOUT_FILENO 1
61 # define STDERR_FILENO 2
66 #include "Windows/WindowsSupport.h"
71 raw_ostream::~raw_ostream() {
72 // raw_ostream's subclasses should take care to flush the buffer
73 // in their destructors.
74 assert(OutBufCur == OutBufStart &&
75 "raw_ostream destructor called with non-empty buffer!");
77 if (BufferMode == InternalBuffer)
78 delete [] OutBufStart;
81 // An out of line virtual method to provide a home for the class vtable.
82 void raw_ostream::handle() {}
84 size_t raw_ostream::preferred_buffer_size() const {
85 // BUFSIZ is intended to be a reasonable default.
89 void raw_ostream::SetBuffered() {
90 // Ask the subclass to determine an appropriate buffer size.
91 if (size_t Size = preferred_buffer_size())
94 // It may return 0, meaning this stream should be unbuffered.
98 void raw_ostream::SetBufferAndMode(char *BufferStart, size_t Size,
100 assert(((Mode == Unbuffered && !BufferStart && Size == 0) ||
101 (Mode != Unbuffered && BufferStart && Size != 0)) &&
102 "stream must be unbuffered or have at least one byte");
103 // Make sure the current buffer is free of content (we can't flush here; the
104 // child buffer management logic will be in write_impl).
105 assert(GetNumBytesInBuffer() == 0 && "Current buffer is non-empty!");
107 if (BufferMode == InternalBuffer)
108 delete [] OutBufStart;
109 OutBufStart = BufferStart;
110 OutBufEnd = OutBufStart+Size;
111 OutBufCur = OutBufStart;
114 assert(OutBufStart <= OutBufEnd && "Invalid size!");
117 raw_ostream &raw_ostream::operator<<(unsigned long N) {
118 write_integer(*this, static_cast<uint64_t>(N), 0, IntegerStyle::Integer);
122 raw_ostream &raw_ostream::operator<<(long N) {
123 write_integer(*this, static_cast<int64_t>(N), 0, IntegerStyle::Integer);
127 raw_ostream &raw_ostream::operator<<(unsigned long long N) {
128 write_integer(*this, static_cast<uint64_t>(N), 0, IntegerStyle::Integer);
132 raw_ostream &raw_ostream::operator<<(long long N) {
133 write_integer(*this, static_cast<int64_t>(N), 0, IntegerStyle::Integer);
137 raw_ostream &raw_ostream::write_hex(unsigned long long N) {
138 llvm::write_hex(*this, N, HexPrintStyle::Lower);
142 raw_ostream &raw_ostream::write_escaped(StringRef Str,
143 bool UseHexEscapes) {
144 for (unsigned char c : Str) {
147 *this << '\\' << '\\';
150 *this << '\\' << 't';
153 *this << '\\' << 'n';
156 *this << '\\' << '"';
159 if (std::isprint(c)) {
164 // Write out the escaped representation.
166 *this << '\\' << 'x';
167 *this << hexdigit((c >> 4 & 0xF));
168 *this << hexdigit((c >> 0) & 0xF);
170 // Always use a full 3-character octal escape.
172 *this << char('0' + ((c >> 6) & 7));
173 *this << char('0' + ((c >> 3) & 7));
174 *this << char('0' + ((c >> 0) & 7));
182 raw_ostream &raw_ostream::operator<<(const void *P) {
183 llvm::write_hex(*this, (uintptr_t)P, HexPrintStyle::PrefixLower);
187 raw_ostream &raw_ostream::operator<<(double N) {
188 llvm::write_double(*this, N, FloatStyle::Exponent);
192 void raw_ostream::flush_nonempty() {
193 assert(OutBufCur > OutBufStart && "Invalid call to flush_nonempty.");
194 size_t Length = OutBufCur - OutBufStart;
195 OutBufCur = OutBufStart;
196 write_impl(OutBufStart, Length);
199 raw_ostream &raw_ostream::write(unsigned char C) {
200 // Group exceptional cases into a single branch.
201 if (LLVM_UNLIKELY(OutBufCur >= OutBufEnd)) {
202 if (LLVM_UNLIKELY(!OutBufStart)) {
203 if (BufferMode == Unbuffered) {
204 write_impl(reinterpret_cast<char*>(&C), 1);
207 // Set up a buffer and start over.
219 raw_ostream &raw_ostream::write(const char *Ptr, size_t Size) {
220 // Group exceptional cases into a single branch.
221 if (LLVM_UNLIKELY(size_t(OutBufEnd - OutBufCur) < Size)) {
222 if (LLVM_UNLIKELY(!OutBufStart)) {
223 if (BufferMode == Unbuffered) {
224 write_impl(Ptr, Size);
227 // Set up a buffer and start over.
229 return write(Ptr, Size);
232 size_t NumBytes = OutBufEnd - OutBufCur;
234 // If the buffer is empty at this point we have a string that is larger
235 // than the buffer. Directly write the chunk that is a multiple of the
236 // preferred buffer size and put the remainder in the buffer.
237 if (LLVM_UNLIKELY(OutBufCur == OutBufStart)) {
238 assert(NumBytes != 0 && "undefined behavior");
239 size_t BytesToWrite = Size - (Size % NumBytes);
240 write_impl(Ptr, BytesToWrite);
241 size_t BytesRemaining = Size - BytesToWrite;
242 if (BytesRemaining > size_t(OutBufEnd - OutBufCur)) {
243 // Too much left over to copy into our buffer.
244 return write(Ptr + BytesToWrite, BytesRemaining);
246 copy_to_buffer(Ptr + BytesToWrite, BytesRemaining);
250 // We don't have enough space in the buffer to fit the string in. Insert as
251 // much as possible, flush and start over with the remainder.
252 copy_to_buffer(Ptr, NumBytes);
254 return write(Ptr + NumBytes, Size - NumBytes);
257 copy_to_buffer(Ptr, Size);
262 void raw_ostream::copy_to_buffer(const char *Ptr, size_t Size) {
263 assert(Size <= size_t(OutBufEnd - OutBufCur) && "Buffer overrun!");
265 // Handle short strings specially, memcpy isn't very good at very short
268 case 4: OutBufCur[3] = Ptr[3]; LLVM_FALLTHROUGH;
269 case 3: OutBufCur[2] = Ptr[2]; LLVM_FALLTHROUGH;
270 case 2: OutBufCur[1] = Ptr[1]; LLVM_FALLTHROUGH;
271 case 1: OutBufCur[0] = Ptr[0]; LLVM_FALLTHROUGH;
274 memcpy(OutBufCur, Ptr, Size);
282 raw_ostream &raw_ostream::operator<<(const format_object_base &Fmt) {
283 // If we have more than a few bytes left in our output buffer, try
284 // formatting directly onto its end.
285 size_t NextBufferSize = 127;
286 size_t BufferBytesLeft = OutBufEnd - OutBufCur;
287 if (BufferBytesLeft > 3) {
288 size_t BytesUsed = Fmt.print(OutBufCur, BufferBytesLeft);
290 // Common case is that we have plenty of space.
291 if (BytesUsed <= BufferBytesLeft) {
292 OutBufCur += BytesUsed;
296 // Otherwise, we overflowed and the return value tells us the size to try
298 NextBufferSize = BytesUsed;
301 // If we got here, we didn't have enough space in the output buffer for the
302 // string. Try printing into a SmallVector that is resized to have enough
303 // space. Iterate until we win.
304 SmallVector<char, 128> V;
307 V.resize(NextBufferSize);
309 // Try formatting into the SmallVector.
310 size_t BytesUsed = Fmt.print(V.data(), NextBufferSize);
312 // If BytesUsed fit into the vector, we win.
313 if (BytesUsed <= NextBufferSize)
314 return write(V.data(), BytesUsed);
316 // Otherwise, try again with a new size.
317 assert(BytesUsed > NextBufferSize && "Didn't grow buffer!?");
318 NextBufferSize = BytesUsed;
322 raw_ostream &raw_ostream::operator<<(const formatv_object_base &Obj) {
328 raw_ostream &raw_ostream::operator<<(const FormattedString &FS) {
329 unsigned Len = FS.Str.size();
330 int PadAmount = FS.Width - Len;
331 if (FS.RightJustify && (PadAmount > 0))
332 this->indent(PadAmount);
333 this->operator<<(FS.Str);
334 if (!FS.RightJustify && (PadAmount > 0))
335 this->indent(PadAmount);
339 raw_ostream &raw_ostream::operator<<(const FormattedNumber &FN) {
342 if (FN.Upper && FN.HexPrefix)
343 Style = HexPrintStyle::PrefixUpper;
344 else if (FN.Upper && !FN.HexPrefix)
345 Style = HexPrintStyle::Upper;
346 else if (!FN.Upper && FN.HexPrefix)
347 Style = HexPrintStyle::PrefixLower;
349 Style = HexPrintStyle::Lower;
350 llvm::write_hex(*this, FN.HexValue, Style, FN.Width);
352 llvm::SmallString<16> Buffer;
353 llvm::raw_svector_ostream Stream(Buffer);
354 llvm::write_integer(Stream, FN.DecValue, 0, IntegerStyle::Integer);
355 if (Buffer.size() < FN.Width)
356 indent(FN.Width - Buffer.size());
362 raw_ostream &raw_ostream::operator<<(const FormattedBytes &FB) {
363 if (FB.Bytes.empty())
366 size_t LineIndex = 0;
367 auto Bytes = FB.Bytes;
368 const size_t Size = Bytes.size();
369 HexPrintStyle HPS = FB.Upper ? HexPrintStyle::Upper : HexPrintStyle::Lower;
370 uint64_t OffsetWidth = 0;
371 if (FB.FirstByteOffset.hasValue()) {
372 // Figure out how many nibbles are needed to print the largest offset
373 // represented by this data set, so that we can align the offset field
374 // to the right width.
375 size_t Lines = Size / FB.NumPerLine;
376 uint64_t MaxOffset = *FB.FirstByteOffset + Lines * FB.NumPerLine;
379 Power = llvm::Log2_64_Ceil(MaxOffset);
380 OffsetWidth = std::max<uint64_t>(4, llvm::alignTo(Power, 4) / 4);
383 // The width of a block of data including all spaces for group separators.
384 unsigned NumByteGroups =
385 alignTo(FB.NumPerLine, FB.ByteGroupSize) / FB.ByteGroupSize;
386 unsigned BlockCharWidth = FB.NumPerLine * 2 + NumByteGroups - 1;
388 while (!Bytes.empty()) {
389 indent(FB.IndentLevel);
391 if (FB.FirstByteOffset.hasValue()) {
392 uint64_t Offset = FB.FirstByteOffset.getValue();
393 llvm::write_hex(*this, Offset + LineIndex, HPS, OffsetWidth);
397 auto Line = Bytes.take_front(FB.NumPerLine);
399 size_t CharsPrinted = 0;
400 // Print the hex bytes for this line in groups
401 for (size_t I = 0; I < Line.size(); ++I, CharsPrinted += 2) {
402 if (I && (I % FB.ByteGroupSize) == 0) {
406 llvm::write_hex(*this, Line[I], HPS, 2);
410 // Print any spaces needed for any bytes that we didn't print on this
411 // line so that the ASCII bytes are correctly aligned.
412 assert(BlockCharWidth >= CharsPrinted);
413 indent(BlockCharWidth - CharsPrinted + 2);
416 // Print the ASCII char values for each byte on this line
417 for (uint8_t Byte : Line) {
419 *this << static_cast<char>(Byte);
426 Bytes = Bytes.drop_front(Line.size());
427 LineIndex += Line.size();
428 if (LineIndex < Size)
434 /// indent - Insert 'NumSpaces' spaces.
435 raw_ostream &raw_ostream::indent(unsigned NumSpaces) {
436 static const char Spaces[] = " "
440 // Usually the indentation is small, handle it with a fastpath.
441 if (NumSpaces < array_lengthof(Spaces))
442 return write(Spaces, NumSpaces);
445 unsigned NumToWrite = std::min(NumSpaces,
446 (unsigned)array_lengthof(Spaces)-1);
447 write(Spaces, NumToWrite);
448 NumSpaces -= NumToWrite;
453 //===----------------------------------------------------------------------===//
455 //===----------------------------------------------------------------------===//
457 // Out of line virtual method.
458 void format_object_base::home() {
461 //===----------------------------------------------------------------------===//
463 //===----------------------------------------------------------------------===//
465 static int getFD(StringRef Filename, std::error_code &EC,
466 sys::fs::OpenFlags Flags) {
467 // Handle "-" as stdout. Note that when we do this, we consider ourself
468 // the owner of stdout. This means that we can do things like close the
469 // file descriptor when we're done and set the "binary" flag globally.
470 if (Filename == "-") {
471 EC = std::error_code();
472 // If user requested binary then put stdout into binary mode if
474 if (!(Flags & sys::fs::F_Text))
475 sys::ChangeStdoutToBinary();
476 return STDOUT_FILENO;
480 EC = sys::fs::openFileForWrite(Filename, FD, Flags);
487 raw_fd_ostream::raw_fd_ostream(StringRef Filename, std::error_code &EC,
488 sys::fs::OpenFlags Flags)
489 : raw_fd_ostream(getFD(Filename, EC, Flags), true) {}
491 /// FD is the file descriptor that this writes to. If ShouldClose is true, this
492 /// closes the file when the stream is destroyed.
493 raw_fd_ostream::raw_fd_ostream(int fd, bool shouldClose, bool unbuffered)
494 : raw_pwrite_stream(unbuffered), FD(fd), ShouldClose(shouldClose),
501 // Get the starting position.
502 off_t loc = ::lseek(FD, 0, SEEK_CUR);
504 // MSVCRT's _lseek(SEEK_CUR) doesn't return -1 for pipes.
505 sys::fs::file_status Status;
506 std::error_code EC = status(FD, Status);
507 SupportsSeeking = !EC && Status.type() == sys::fs::file_type::regular_file;
509 SupportsSeeking = loc != (off_t)-1;
511 if (!SupportsSeeking)
514 pos = static_cast<uint64_t>(loc);
517 raw_fd_ostream::~raw_fd_ostream() {
520 if (ShouldClose && sys::Process::SafelyCloseFileDescriptor(FD))
525 // On mingw, global dtors should not call exit().
526 // report_fatal_error() invokes exit(). We know report_fatal_error()
527 // might not write messages to stderr when any errors were detected
532 // If there are any pending errors, report them now. Clients wishing
533 // to avoid report_fatal_error calls should check for errors with
534 // has_error() and clear the error flag with clear_error() before
535 // destructing raw_ostream objects which may have errors.
537 report_fatal_error("IO failure on output stream.", /*GenCrashDiag=*/false);
540 void raw_fd_ostream::write_impl(const char *Ptr, size_t Size) {
541 assert(FD >= 0 && "File already closed.");
544 #ifndef LLVM_ON_WIN32
545 bool ShouldWriteInChunks = false;
547 // Writing a large size of output to Windows console returns ENOMEM. It seems
548 // that, prior to Windows 8, WriteFile() is redirecting to WriteConsole(), and
549 // the latter has a size limit (66000 bytes or less, depending on heap usage).
550 bool ShouldWriteInChunks = !!::_isatty(FD) && !RunningWindows8OrGreater();
554 size_t ChunkSize = Size;
555 if (ChunkSize > 32767 && ShouldWriteInChunks)
558 ssize_t ret = ::write(FD, Ptr, ChunkSize);
561 // If it's a recoverable error, swallow it and retry the write.
563 // Ideally we wouldn't ever see EAGAIN or EWOULDBLOCK here, since
564 // raw_ostream isn't designed to do non-blocking I/O. However, some
565 // programs, such as old versions of bjam, have mistakenly used
566 // O_NONBLOCK. For compatibility, emulate blocking semantics by
567 // spinning until the write succeeds. If you don't want spinning,
568 // don't use O_NONBLOCK file descriptors with raw_ostream.
569 if (errno == EINTR || errno == EAGAIN
571 || errno == EWOULDBLOCK
576 // Otherwise it's a non-recoverable error. Note it and quit.
581 // The write may have written some or all of the data. Update the
582 // size and buffer pointer to reflect the remainder that needs
583 // to be written. If there are no bytes left, we're done.
589 void raw_fd_ostream::close() {
593 if (sys::Process::SafelyCloseFileDescriptor(FD))
598 uint64_t raw_fd_ostream::seek(uint64_t off) {
599 assert(SupportsSeeking && "Stream does not support seeking!");
601 pos = ::lseek(FD, off, SEEK_SET);
602 if (pos == (uint64_t)-1)
607 void raw_fd_ostream::pwrite_impl(const char *Ptr, size_t Size,
609 uint64_t Pos = tell();
615 size_t raw_fd_ostream::preferred_buffer_size() const {
616 #if !defined(_MSC_VER) && !defined(__MINGW32__) && !defined(__minix)
617 // Windows and Minix have no st_blksize.
618 assert(FD >= 0 && "File not yet open!");
620 if (fstat(FD, &statbuf) != 0)
623 // If this is a terminal, don't use buffering. Line buffering
624 // would be a more traditional thing to do, but it's not worth
626 if (S_ISCHR(statbuf.st_mode) && isatty(FD))
628 // Return the preferred block size.
629 return statbuf.st_blksize;
631 return raw_ostream::preferred_buffer_size();
635 raw_ostream &raw_fd_ostream::changeColor(enum Colors colors, bool bold,
637 if (sys::Process::ColorNeedsFlush())
639 const char *colorcode =
640 (colors == SAVEDCOLOR) ? sys::Process::OutputBold(bg)
641 : sys::Process::OutputColor(colors, bold, bg);
643 size_t len = strlen(colorcode);
644 write(colorcode, len);
645 // don't account colors towards output characters
651 raw_ostream &raw_fd_ostream::resetColor() {
652 if (sys::Process::ColorNeedsFlush())
654 const char *colorcode = sys::Process::ResetColor();
656 size_t len = strlen(colorcode);
657 write(colorcode, len);
658 // don't account colors towards output characters
664 raw_ostream &raw_fd_ostream::reverseColor() {
665 if (sys::Process::ColorNeedsFlush())
667 const char *colorcode = sys::Process::OutputReverse();
669 size_t len = strlen(colorcode);
670 write(colorcode, len);
671 // don't account colors towards output characters
677 bool raw_fd_ostream::is_displayed() const {
678 return sys::Process::FileDescriptorIsDisplayed(FD);
681 bool raw_fd_ostream::has_colors() const {
682 return sys::Process::FileDescriptorHasColors(FD);
685 //===----------------------------------------------------------------------===//
686 // outs(), errs(), nulls()
687 //===----------------------------------------------------------------------===//
689 /// outs() - This returns a reference to a raw_ostream for standard output.
690 /// Use it like: outs() << "foo" << "bar";
691 raw_ostream &llvm::outs() {
692 // Set buffer settings to model stdout behavior. Delete the file descriptor
693 // when the program exits, forcing error detection. This means that if you
694 // ever call outs(), you can't open another raw_fd_ostream on stdout, as we'll
695 // close stdout twice and print an error the second time.
697 static raw_fd_ostream S("-", EC, sys::fs::F_None);
702 /// errs() - This returns a reference to a raw_ostream for standard error.
703 /// Use it like: errs() << "foo" << "bar";
704 raw_ostream &llvm::errs() {
705 // Set standard error to be unbuffered by default.
706 static raw_fd_ostream S(STDERR_FILENO, false, true);
710 /// nulls() - This returns a reference to a raw_ostream which discards output.
711 raw_ostream &llvm::nulls() {
712 static raw_null_ostream S;
716 //===----------------------------------------------------------------------===//
717 // raw_string_ostream
718 //===----------------------------------------------------------------------===//
720 raw_string_ostream::~raw_string_ostream() {
724 void raw_string_ostream::write_impl(const char *Ptr, size_t Size) {
725 OS.append(Ptr, Size);
728 //===----------------------------------------------------------------------===//
729 // raw_svector_ostream
730 //===----------------------------------------------------------------------===//
732 uint64_t raw_svector_ostream::current_pos() const { return OS.size(); }
734 void raw_svector_ostream::write_impl(const char *Ptr, size_t Size) {
735 OS.append(Ptr, Ptr + Size);
738 void raw_svector_ostream::pwrite_impl(const char *Ptr, size_t Size,
740 memcpy(OS.data() + Offset, Ptr, Size);
743 //===----------------------------------------------------------------------===//
745 //===----------------------------------------------------------------------===//
747 raw_null_ostream::~raw_null_ostream() {
749 // ~raw_ostream asserts that the buffer is empty. This isn't necessary
750 // with raw_null_ostream, but it's better to have raw_null_ostream follow
751 // the rules than to change the rules just for raw_null_ostream.
756 void raw_null_ostream::write_impl(const char *Ptr, size_t Size) {
759 uint64_t raw_null_ostream::current_pos() const {
763 void raw_null_ostream::pwrite_impl(const char *Ptr, size_t Size,