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/MathExtras.h"
24 #include "llvm/Support/Process.h"
25 #include "llvm/Support/Program.h"
29 #include <system_error>
31 // <fcntl.h> may provide O_BINARY.
32 #if defined(HAVE_FCNTL_H)
36 #if defined(HAVE_UNISTD_H)
39 #if defined(HAVE_SYS_UIO_H) && defined(HAVE_WRITEV)
43 #if defined(__CYGWIN__)
50 # define STDIN_FILENO 0
53 # define STDOUT_FILENO 1
56 # define STDERR_FILENO 2
62 raw_ostream::~raw_ostream() {
63 // raw_ostream's subclasses should take care to flush the buffer
64 // in their destructors.
65 assert(OutBufCur == OutBufStart &&
66 "raw_ostream destructor called with non-empty buffer!");
68 if (BufferMode == InternalBuffer)
69 delete [] OutBufStart;
72 // An out of line virtual method to provide a home for the class vtable.
73 void raw_ostream::handle() {}
75 size_t raw_ostream::preferred_buffer_size() const {
76 // BUFSIZ is intended to be a reasonable default.
80 void raw_ostream::SetBuffered() {
81 // Ask the subclass to determine an appropriate buffer size.
82 if (size_t Size = preferred_buffer_size())
85 // It may return 0, meaning this stream should be unbuffered.
89 void raw_ostream::SetBufferAndMode(char *BufferStart, size_t Size,
91 assert(((Mode == Unbuffered && !BufferStart && Size == 0) ||
92 (Mode != Unbuffered && BufferStart && Size != 0)) &&
93 "stream must be unbuffered or have at least one byte");
94 // Make sure the current buffer is free of content (we can't flush here; the
95 // child buffer management logic will be in write_impl).
96 assert(GetNumBytesInBuffer() == 0 && "Current buffer is non-empty!");
98 if (BufferMode == InternalBuffer)
99 delete [] OutBufStart;
100 OutBufStart = BufferStart;
101 OutBufEnd = OutBufStart+Size;
102 OutBufCur = OutBufStart;
105 assert(OutBufStart <= OutBufEnd && "Invalid size!");
108 raw_ostream &raw_ostream::operator<<(unsigned long N) {
109 // Zero is a special case.
113 char NumberBuffer[20];
114 char *EndPtr = NumberBuffer+sizeof(NumberBuffer);
115 char *CurPtr = EndPtr;
118 *--CurPtr = '0' + char(N % 10);
121 return write(CurPtr, EndPtr-CurPtr);
124 raw_ostream &raw_ostream::operator<<(long N) {
127 // Avoid undefined behavior on LONG_MIN with a cast.
128 N = -(unsigned long)N;
131 return this->operator<<(static_cast<unsigned long>(N));
134 raw_ostream &raw_ostream::operator<<(unsigned long long N) {
135 // Output using 32-bit div/mod when possible.
136 if (N == static_cast<unsigned long>(N))
137 return this->operator<<(static_cast<unsigned long>(N));
139 char NumberBuffer[20];
140 char *EndPtr = NumberBuffer+sizeof(NumberBuffer);
141 char *CurPtr = EndPtr;
144 *--CurPtr = '0' + char(N % 10);
147 return write(CurPtr, EndPtr-CurPtr);
150 raw_ostream &raw_ostream::operator<<(long long N) {
153 // Avoid undefined behavior on INT64_MIN with a cast.
154 N = -(unsigned long long)N;
157 return this->operator<<(static_cast<unsigned long long>(N));
160 raw_ostream &raw_ostream::write_hex(unsigned long long N) {
161 // Zero is a special case.
165 char NumberBuffer[20];
166 char *EndPtr = NumberBuffer+sizeof(NumberBuffer);
167 char *CurPtr = EndPtr;
170 uintptr_t x = N % 16;
171 *--CurPtr = (x < 10 ? '0' + x : 'a' + x - 10);
175 return write(CurPtr, EndPtr-CurPtr);
178 raw_ostream &raw_ostream::write_escaped(StringRef Str,
179 bool UseHexEscapes) {
180 for (unsigned i = 0, e = Str.size(); i != e; ++i) {
181 unsigned char c = Str[i];
185 *this << '\\' << '\\';
188 *this << '\\' << 't';
191 *this << '\\' << 'n';
194 *this << '\\' << '"';
197 if (std::isprint(c)) {
202 // Write out the escaped representation.
204 *this << '\\' << 'x';
205 *this << hexdigit((c >> 4 & 0xF));
206 *this << hexdigit((c >> 0) & 0xF);
208 // Always use a full 3-character octal escape.
210 *this << char('0' + ((c >> 6) & 7));
211 *this << char('0' + ((c >> 3) & 7));
212 *this << char('0' + ((c >> 0) & 7));
220 raw_ostream &raw_ostream::operator<<(const void *P) {
223 return write_hex((uintptr_t) P);
226 raw_ostream &raw_ostream::operator<<(double N) {
228 // On MSVCRT and compatible, output of %e is incompatible to Posix
229 // by default. Number of exponent digits should be at least 2. "%+03d"
230 // FIXME: Implement our formatter to here or Support/Format.h!
231 #if __cplusplus >= 201103L && defined(__MINGW32__)
232 // FIXME: It should be generic to C++11.
233 if (N == 0.0 && std::signbit(N))
234 return *this << "-0.000000e+00";
236 int fpcl = _fpclass(N);
239 if (fpcl == _FPCLASS_NZ)
240 return *this << "-0.000000e+00";
245 len = format("%e", N).snprint(buf, sizeof(buf));
246 if (len <= sizeof(buf) - 2) {
247 if (len >= 5 && buf[len - 5] == 'e' && buf[len - 3] == '0') {
248 int cs = buf[len - 4];
249 if (cs == '+' || cs == '-') {
250 int c1 = buf[len - 2];
251 int c0 = buf[len - 1];
252 if (isdigit(static_cast<unsigned char>(c1)) &&
253 isdigit(static_cast<unsigned char>(c0))) {
254 // Trim leading '0': "...e+012" -> "...e+12\0"
261 return this->operator<<(buf);
264 return this->operator<<(format("%e", N));
269 void raw_ostream::flush_nonempty() {
270 assert(OutBufCur > OutBufStart && "Invalid call to flush_nonempty.");
271 size_t Length = OutBufCur - OutBufStart;
272 OutBufCur = OutBufStart;
273 write_impl(OutBufStart, Length);
276 raw_ostream &raw_ostream::write(unsigned char C) {
277 // Group exceptional cases into a single branch.
278 if (LLVM_UNLIKELY(OutBufCur >= OutBufEnd)) {
279 if (LLVM_UNLIKELY(!OutBufStart)) {
280 if (BufferMode == Unbuffered) {
281 write_impl(reinterpret_cast<char*>(&C), 1);
284 // Set up a buffer and start over.
296 raw_ostream &raw_ostream::write(const char *Ptr, size_t Size) {
297 // Group exceptional cases into a single branch.
298 if (LLVM_UNLIKELY(size_t(OutBufEnd - OutBufCur) < Size)) {
299 if (LLVM_UNLIKELY(!OutBufStart)) {
300 if (BufferMode == Unbuffered) {
301 write_impl(Ptr, Size);
304 // Set up a buffer and start over.
306 return write(Ptr, Size);
309 size_t NumBytes = OutBufEnd - OutBufCur;
311 // If the buffer is empty at this point we have a string that is larger
312 // than the buffer. Directly write the chunk that is a multiple of the
313 // preferred buffer size and put the remainder in the buffer.
314 if (LLVM_UNLIKELY(OutBufCur == OutBufStart)) {
315 assert(NumBytes != 0 && "undefined behavior");
316 size_t BytesToWrite = Size - (Size % NumBytes);
317 write_impl(Ptr, BytesToWrite);
318 size_t BytesRemaining = Size - BytesToWrite;
319 if (BytesRemaining > size_t(OutBufEnd - OutBufCur)) {
320 // Too much left over to copy into our buffer.
321 return write(Ptr + BytesToWrite, BytesRemaining);
323 copy_to_buffer(Ptr + BytesToWrite, BytesRemaining);
327 // We don't have enough space in the buffer to fit the string in. Insert as
328 // much as possible, flush and start over with the remainder.
329 copy_to_buffer(Ptr, NumBytes);
331 return write(Ptr + NumBytes, Size - NumBytes);
334 copy_to_buffer(Ptr, Size);
339 void raw_ostream::copy_to_buffer(const char *Ptr, size_t Size) {
340 assert(Size <= size_t(OutBufEnd - OutBufCur) && "Buffer overrun!");
342 // Handle short strings specially, memcpy isn't very good at very short
345 case 4: OutBufCur[3] = Ptr[3]; // FALL THROUGH
346 case 3: OutBufCur[2] = Ptr[2]; // FALL THROUGH
347 case 2: OutBufCur[1] = Ptr[1]; // FALL THROUGH
348 case 1: OutBufCur[0] = Ptr[0]; // FALL THROUGH
351 memcpy(OutBufCur, Ptr, Size);
359 raw_ostream &raw_ostream::operator<<(const format_object_base &Fmt) {
360 // If we have more than a few bytes left in our output buffer, try
361 // formatting directly onto its end.
362 size_t NextBufferSize = 127;
363 size_t BufferBytesLeft = OutBufEnd - OutBufCur;
364 if (BufferBytesLeft > 3) {
365 size_t BytesUsed = Fmt.print(OutBufCur, BufferBytesLeft);
367 // Common case is that we have plenty of space.
368 if (BytesUsed <= BufferBytesLeft) {
369 OutBufCur += BytesUsed;
373 // Otherwise, we overflowed and the return value tells us the size to try
375 NextBufferSize = BytesUsed;
378 // If we got here, we didn't have enough space in the output buffer for the
379 // string. Try printing into a SmallVector that is resized to have enough
380 // space. Iterate until we win.
381 SmallVector<char, 128> V;
384 V.resize(NextBufferSize);
386 // Try formatting into the SmallVector.
387 size_t BytesUsed = Fmt.print(V.data(), NextBufferSize);
389 // If BytesUsed fit into the vector, we win.
390 if (BytesUsed <= NextBufferSize)
391 return write(V.data(), BytesUsed);
393 // Otherwise, try again with a new size.
394 assert(BytesUsed > NextBufferSize && "Didn't grow buffer!?");
395 NextBufferSize = BytesUsed;
399 raw_ostream &raw_ostream::operator<<(const FormattedString &FS) {
400 unsigned Len = FS.Str.size();
401 int PadAmount = FS.Width - Len;
402 if (FS.RightJustify && (PadAmount > 0))
403 this->indent(PadAmount);
404 this->operator<<(FS.Str);
405 if (!FS.RightJustify && (PadAmount > 0))
406 this->indent(PadAmount);
410 raw_ostream &raw_ostream::operator<<(const FormattedNumber &FN) {
412 unsigned Nibbles = (64 - countLeadingZeros(FN.HexValue)+3)/4;
413 unsigned PrefixChars = FN.HexPrefix ? 2 : 0;
414 unsigned Width = std::max(FN.Width, Nibbles + PrefixChars);
416 char NumberBuffer[20] = "0x0000000000000000";
418 NumberBuffer[1] = '0';
419 char *EndPtr = NumberBuffer+Width;
420 char *CurPtr = EndPtr;
421 const char A = FN.Upper ? 'A' : 'a';
422 unsigned long long N = FN.HexValue;
424 uintptr_t x = N % 16;
425 *--CurPtr = (x < 10 ? '0' + x : A + x - 10);
429 return write(NumberBuffer, Width);
431 // Zero is a special case.
432 if (FN.DecValue == 0) {
433 this->indent(FN.Width-1);
436 char NumberBuffer[32];
437 char *EndPtr = NumberBuffer+sizeof(NumberBuffer);
438 char *CurPtr = EndPtr;
439 bool Neg = (FN.DecValue < 0);
440 uint64_t N = Neg ? -static_cast<uint64_t>(FN.DecValue) : FN.DecValue;
442 *--CurPtr = '0' + char(N % 10);
445 int Len = EndPtr - CurPtr;
446 int Pad = FN.Width - Len;
453 return write(CurPtr, Len);
458 /// indent - Insert 'NumSpaces' spaces.
459 raw_ostream &raw_ostream::indent(unsigned NumSpaces) {
460 static const char Spaces[] = " "
464 // Usually the indentation is small, handle it with a fastpath.
465 if (NumSpaces < array_lengthof(Spaces))
466 return write(Spaces, NumSpaces);
469 unsigned NumToWrite = std::min(NumSpaces,
470 (unsigned)array_lengthof(Spaces)-1);
471 write(Spaces, NumToWrite);
472 NumSpaces -= NumToWrite;
478 //===----------------------------------------------------------------------===//
480 //===----------------------------------------------------------------------===//
482 // Out of line virtual method.
483 void format_object_base::home() {
486 //===----------------------------------------------------------------------===//
488 //===----------------------------------------------------------------------===//
490 static int getFD(StringRef Filename, std::error_code &EC,
491 sys::fs::OpenFlags Flags) {
492 // Handle "-" as stdout. Note that when we do this, we consider ourself
493 // the owner of stdout. This means that we can do things like close the
494 // file descriptor when we're done and set the "binary" flag globally.
495 if (Filename == "-") {
496 EC = std::error_code();
497 // If user requested binary then put stdout into binary mode if
499 if (!(Flags & sys::fs::F_Text))
500 sys::ChangeStdoutToBinary();
501 return STDOUT_FILENO;
505 EC = sys::fs::openFileForWrite(Filename, FD, Flags);
512 raw_fd_ostream::raw_fd_ostream(StringRef Filename, std::error_code &EC,
513 sys::fs::OpenFlags Flags)
514 : raw_fd_ostream(getFD(Filename, EC, Flags), true) {}
516 /// FD is the file descriptor that this writes to. If ShouldClose is true, this
517 /// closes the file when the stream is destroyed.
518 raw_fd_ostream::raw_fd_ostream(int fd, bool shouldClose, bool unbuffered)
519 : raw_pwrite_stream(unbuffered), FD(fd), ShouldClose(shouldClose),
520 Error(false), UseAtomicWrites(false) {
526 // Get the starting position.
527 off_t loc = ::lseek(FD, 0, SEEK_CUR);
529 // MSVCRT's _lseek(SEEK_CUR) doesn't return -1 for pipes.
530 sys::fs::file_status Status;
531 std::error_code EC = status(FD, Status);
532 SupportsSeeking = !EC && Status.type() == sys::fs::file_type::regular_file;
534 SupportsSeeking = loc != (off_t)-1;
536 if (!SupportsSeeking)
539 pos = static_cast<uint64_t>(loc);
542 raw_fd_ostream::~raw_fd_ostream() {
545 if (ShouldClose && sys::Process::SafelyCloseFileDescriptor(FD))
550 // On mingw, global dtors should not call exit().
551 // report_fatal_error() invokes exit(). We know report_fatal_error()
552 // might not write messages to stderr when any errors were detected
557 // If there are any pending errors, report them now. Clients wishing
558 // to avoid report_fatal_error calls should check for errors with
559 // has_error() and clear the error flag with clear_error() before
560 // destructing raw_ostream objects which may have errors.
562 report_fatal_error("IO failure on output stream.", /*GenCrashDiag=*/false);
566 void raw_fd_ostream::write_impl(const char *Ptr, size_t Size) {
567 assert(FD >= 0 && "File already closed.");
573 // Check whether we should attempt to use atomic writes.
574 if (LLVM_LIKELY(!UseAtomicWrites)) {
575 ret = ::write(FD, Ptr, Size);
577 // Use ::writev() where available.
578 #if defined(HAVE_WRITEV)
579 const void *Addr = static_cast<const void *>(Ptr);
580 struct iovec IOV = {const_cast<void *>(Addr), Size };
581 ret = ::writev(FD, &IOV, 1);
583 ret = ::write(FD, Ptr, Size);
588 // If it's a recoverable error, swallow it and retry the write.
590 // Ideally we wouldn't ever see EAGAIN or EWOULDBLOCK here, since
591 // raw_ostream isn't designed to do non-blocking I/O. However, some
592 // programs, such as old versions of bjam, have mistakenly used
593 // O_NONBLOCK. For compatibility, emulate blocking semantics by
594 // spinning until the write succeeds. If you don't want spinning,
595 // don't use O_NONBLOCK file descriptors with raw_ostream.
596 if (errno == EINTR || errno == EAGAIN
598 || errno == EWOULDBLOCK
603 // Otherwise it's a non-recoverable error. Note it and quit.
608 // The write may have written some or all of the data. Update the
609 // size and buffer pointer to reflect the remainder that needs
610 // to be written. If there are no bytes left, we're done.
616 void raw_fd_ostream::close() {
620 if (sys::Process::SafelyCloseFileDescriptor(FD))
625 uint64_t raw_fd_ostream::seek(uint64_t off) {
627 pos = ::lseek(FD, off, SEEK_SET);
628 if (pos == (uint64_t)-1)
633 void raw_fd_ostream::pwrite_impl(const char *Ptr, size_t Size,
635 uint64_t Pos = tell();
641 size_t raw_fd_ostream::preferred_buffer_size() const {
642 #if !defined(_MSC_VER) && !defined(__MINGW32__) && !defined(__minix)
643 // Windows and Minix have no st_blksize.
644 assert(FD >= 0 && "File not yet open!");
646 if (fstat(FD, &statbuf) != 0)
649 // If this is a terminal, don't use buffering. Line buffering
650 // would be a more traditional thing to do, but it's not worth
652 if (S_ISCHR(statbuf.st_mode) && isatty(FD))
654 // Return the preferred block size.
655 return statbuf.st_blksize;
657 return raw_ostream::preferred_buffer_size();
661 raw_ostream &raw_fd_ostream::changeColor(enum Colors colors, bool bold,
663 if (sys::Process::ColorNeedsFlush())
665 const char *colorcode =
666 (colors == SAVEDCOLOR) ? sys::Process::OutputBold(bg)
667 : sys::Process::OutputColor(colors, bold, bg);
669 size_t len = strlen(colorcode);
670 write(colorcode, len);
671 // don't account colors towards output characters
677 raw_ostream &raw_fd_ostream::resetColor() {
678 if (sys::Process::ColorNeedsFlush())
680 const char *colorcode = sys::Process::ResetColor();
682 size_t len = strlen(colorcode);
683 write(colorcode, len);
684 // don't account colors towards output characters
690 raw_ostream &raw_fd_ostream::reverseColor() {
691 if (sys::Process::ColorNeedsFlush())
693 const char *colorcode = sys::Process::OutputReverse();
695 size_t len = strlen(colorcode);
696 write(colorcode, len);
697 // don't account colors towards output characters
703 bool raw_fd_ostream::is_displayed() const {
704 return sys::Process::FileDescriptorIsDisplayed(FD);
707 bool raw_fd_ostream::has_colors() const {
708 return sys::Process::FileDescriptorHasColors(FD);
711 //===----------------------------------------------------------------------===//
712 // outs(), errs(), nulls()
713 //===----------------------------------------------------------------------===//
715 /// outs() - This returns a reference to a raw_ostream for standard output.
716 /// Use it like: outs() << "foo" << "bar";
717 raw_ostream &llvm::outs() {
718 // Set buffer settings to model stdout behavior.
719 // Delete the file descriptor when the program exits, forcing error
720 // detection. If you don't want this behavior, don't use outs().
722 static raw_fd_ostream S("-", EC, sys::fs::F_None);
727 /// errs() - This returns a reference to a raw_ostream for standard error.
728 /// Use it like: errs() << "foo" << "bar";
729 raw_ostream &llvm::errs() {
730 // Set standard error to be unbuffered by default.
731 static raw_fd_ostream S(STDERR_FILENO, false, true);
735 /// nulls() - This returns a reference to a raw_ostream which discards output.
736 raw_ostream &llvm::nulls() {
737 static raw_null_ostream S;
742 //===----------------------------------------------------------------------===//
743 // raw_string_ostream
744 //===----------------------------------------------------------------------===//
746 raw_string_ostream::~raw_string_ostream() {
750 void raw_string_ostream::write_impl(const char *Ptr, size_t Size) {
751 OS.append(Ptr, Size);
754 //===----------------------------------------------------------------------===//
755 // raw_svector_ostream
756 //===----------------------------------------------------------------------===//
758 // The raw_svector_ostream implementation uses the SmallVector itself as the
759 // buffer for the raw_ostream. We guarantee that the raw_ostream buffer is
760 // always pointing past the end of the vector, but within the vector
761 // capacity. This allows raw_ostream to write directly into the correct place,
762 // and we only need to set the vector size when the data is flushed.
764 raw_svector_ostream::raw_svector_ostream(SmallVectorImpl<char> &O, unsigned)
767 raw_svector_ostream::raw_svector_ostream(SmallVectorImpl<char> &O) : OS(O) {
771 void raw_svector_ostream::init() {
772 // Set up the initial external buffer. We make sure that the buffer has at
773 // least 128 bytes free; raw_ostream itself only requires 64, but we want to
774 // make sure that we don't grow the buffer unnecessarily on destruction (when
775 // the data is flushed). See the FIXME below.
776 OS.reserve(OS.size() + 128);
777 SetBuffer(OS.end(), OS.capacity() - OS.size());
780 raw_svector_ostream::~raw_svector_ostream() {
781 // FIXME: Prevent resizing during this flush().
785 void raw_svector_ostream::pwrite_impl(const char *Ptr, size_t Size,
788 memcpy(OS.begin() + Offset, Ptr, Size);
791 /// resync - This is called when the SmallVector we're appending to is changed
792 /// outside of the raw_svector_ostream's control. It is only safe to do this
793 /// if the raw_svector_ostream has previously been flushed.
794 void raw_svector_ostream::resync() {
795 assert(GetNumBytesInBuffer() == 0 && "Didn't flush before mutating vector");
797 if (OS.capacity() - OS.size() < 64)
798 OS.reserve(OS.capacity() * 2);
799 SetBuffer(OS.end(), OS.capacity() - OS.size());
802 void raw_svector_ostream::write_impl(const char *Ptr, size_t Size) {
803 if (Ptr == OS.end()) {
804 // Grow the buffer to include the scratch area without copying.
805 size_t NewSize = OS.size() + Size;
806 assert(NewSize <= OS.capacity() && "Invalid write_impl() call!");
807 OS.set_size(NewSize);
809 assert(!GetNumBytesInBuffer());
810 OS.append(Ptr, Ptr + Size);
813 OS.reserve(OS.size() + 64);
814 SetBuffer(OS.end(), OS.capacity() - OS.size());
817 uint64_t raw_svector_ostream::current_pos() const {
821 StringRef raw_svector_ostream::str() {
823 return StringRef(OS.begin(), OS.size());
826 //===----------------------------------------------------------------------===//
828 //===----------------------------------------------------------------------===//
830 raw_null_ostream::~raw_null_ostream() {
832 // ~raw_ostream asserts that the buffer is empty. This isn't necessary
833 // with raw_null_ostream, but it's better to have raw_null_ostream follow
834 // the rules than to change the rules just for raw_null_ostream.
839 void raw_null_ostream::write_impl(const char *Ptr, size_t Size) {
842 uint64_t raw_null_ostream::current_pos() const {
846 void raw_null_ostream::pwrite_impl(const char *Ptr, size_t Size,