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));
267 raw_ostream &raw_ostream::operator<<(Printable P) {
273 void raw_ostream::flush_nonempty() {
274 assert(OutBufCur > OutBufStart && "Invalid call to flush_nonempty.");
275 size_t Length = OutBufCur - OutBufStart;
276 OutBufCur = OutBufStart;
277 write_impl(OutBufStart, Length);
280 raw_ostream &raw_ostream::write(unsigned char C) {
281 // Group exceptional cases into a single branch.
282 if (LLVM_UNLIKELY(OutBufCur >= OutBufEnd)) {
283 if (LLVM_UNLIKELY(!OutBufStart)) {
284 if (BufferMode == Unbuffered) {
285 write_impl(reinterpret_cast<char*>(&C), 1);
288 // Set up a buffer and start over.
300 raw_ostream &raw_ostream::write(const char *Ptr, size_t Size) {
301 // Group exceptional cases into a single branch.
302 if (LLVM_UNLIKELY(size_t(OutBufEnd - OutBufCur) < Size)) {
303 if (LLVM_UNLIKELY(!OutBufStart)) {
304 if (BufferMode == Unbuffered) {
305 write_impl(Ptr, Size);
308 // Set up a buffer and start over.
310 return write(Ptr, Size);
313 size_t NumBytes = OutBufEnd - OutBufCur;
315 // If the buffer is empty at this point we have a string that is larger
316 // than the buffer. Directly write the chunk that is a multiple of the
317 // preferred buffer size and put the remainder in the buffer.
318 if (LLVM_UNLIKELY(OutBufCur == OutBufStart)) {
319 assert(NumBytes != 0 && "undefined behavior");
320 size_t BytesToWrite = Size - (Size % NumBytes);
321 write_impl(Ptr, BytesToWrite);
322 size_t BytesRemaining = Size - BytesToWrite;
323 if (BytesRemaining > size_t(OutBufEnd - OutBufCur)) {
324 // Too much left over to copy into our buffer.
325 return write(Ptr + BytesToWrite, BytesRemaining);
327 copy_to_buffer(Ptr + BytesToWrite, BytesRemaining);
331 // We don't have enough space in the buffer to fit the string in. Insert as
332 // much as possible, flush and start over with the remainder.
333 copy_to_buffer(Ptr, NumBytes);
335 return write(Ptr + NumBytes, Size - NumBytes);
338 copy_to_buffer(Ptr, Size);
343 void raw_ostream::copy_to_buffer(const char *Ptr, size_t Size) {
344 assert(Size <= size_t(OutBufEnd - OutBufCur) && "Buffer overrun!");
346 // Handle short strings specially, memcpy isn't very good at very short
349 case 4: OutBufCur[3] = Ptr[3]; // FALL THROUGH
350 case 3: OutBufCur[2] = Ptr[2]; // FALL THROUGH
351 case 2: OutBufCur[1] = Ptr[1]; // FALL THROUGH
352 case 1: OutBufCur[0] = Ptr[0]; // FALL THROUGH
355 memcpy(OutBufCur, Ptr, Size);
363 raw_ostream &raw_ostream::operator<<(const format_object_base &Fmt) {
364 // If we have more than a few bytes left in our output buffer, try
365 // formatting directly onto its end.
366 size_t NextBufferSize = 127;
367 size_t BufferBytesLeft = OutBufEnd - OutBufCur;
368 if (BufferBytesLeft > 3) {
369 size_t BytesUsed = Fmt.print(OutBufCur, BufferBytesLeft);
371 // Common case is that we have plenty of space.
372 if (BytesUsed <= BufferBytesLeft) {
373 OutBufCur += BytesUsed;
377 // Otherwise, we overflowed and the return value tells us the size to try
379 NextBufferSize = BytesUsed;
382 // If we got here, we didn't have enough space in the output buffer for the
383 // string. Try printing into a SmallVector that is resized to have enough
384 // space. Iterate until we win.
385 SmallVector<char, 128> V;
388 V.resize(NextBufferSize);
390 // Try formatting into the SmallVector.
391 size_t BytesUsed = Fmt.print(V.data(), NextBufferSize);
393 // If BytesUsed fit into the vector, we win.
394 if (BytesUsed <= NextBufferSize)
395 return write(V.data(), BytesUsed);
397 // Otherwise, try again with a new size.
398 assert(BytesUsed > NextBufferSize && "Didn't grow buffer!?");
399 NextBufferSize = BytesUsed;
403 raw_ostream &raw_ostream::operator<<(const FormattedString &FS) {
404 unsigned Len = FS.Str.size();
405 int PadAmount = FS.Width - Len;
406 if (FS.RightJustify && (PadAmount > 0))
407 this->indent(PadAmount);
408 this->operator<<(FS.Str);
409 if (!FS.RightJustify && (PadAmount > 0))
410 this->indent(PadAmount);
414 raw_ostream &raw_ostream::operator<<(const FormattedNumber &FN) {
416 unsigned Nibbles = (64 - countLeadingZeros(FN.HexValue)+3)/4;
417 unsigned PrefixChars = FN.HexPrefix ? 2 : 0;
418 unsigned Width = std::max(FN.Width, Nibbles + PrefixChars);
420 char NumberBuffer[20] = "0x0000000000000000";
422 NumberBuffer[1] = '0';
423 char *EndPtr = NumberBuffer+Width;
424 char *CurPtr = EndPtr;
425 const char A = FN.Upper ? 'A' : 'a';
426 unsigned long long N = FN.HexValue;
428 uintptr_t x = N % 16;
429 *--CurPtr = (x < 10 ? '0' + x : A + x - 10);
433 return write(NumberBuffer, Width);
435 // Zero is a special case.
436 if (FN.DecValue == 0) {
437 this->indent(FN.Width-1);
440 char NumberBuffer[32];
441 char *EndPtr = NumberBuffer+sizeof(NumberBuffer);
442 char *CurPtr = EndPtr;
443 bool Neg = (FN.DecValue < 0);
444 uint64_t N = Neg ? -static_cast<uint64_t>(FN.DecValue) : FN.DecValue;
446 *--CurPtr = '0' + char(N % 10);
449 int Len = EndPtr - CurPtr;
450 int Pad = FN.Width - Len;
457 return write(CurPtr, Len);
462 /// indent - Insert 'NumSpaces' spaces.
463 raw_ostream &raw_ostream::indent(unsigned NumSpaces) {
464 static const char Spaces[] = " "
468 // Usually the indentation is small, handle it with a fastpath.
469 if (NumSpaces < array_lengthof(Spaces))
470 return write(Spaces, NumSpaces);
473 unsigned NumToWrite = std::min(NumSpaces,
474 (unsigned)array_lengthof(Spaces)-1);
475 write(Spaces, NumToWrite);
476 NumSpaces -= NumToWrite;
482 //===----------------------------------------------------------------------===//
484 //===----------------------------------------------------------------------===//
486 // Out of line virtual method.
487 void format_object_base::home() {
490 //===----------------------------------------------------------------------===//
492 //===----------------------------------------------------------------------===//
494 static int getFD(StringRef Filename, std::error_code &EC,
495 sys::fs::OpenFlags Flags) {
496 // Handle "-" as stdout. Note that when we do this, we consider ourself
497 // the owner of stdout. This means that we can do things like close the
498 // file descriptor when we're done and set the "binary" flag globally.
499 if (Filename == "-") {
500 EC = std::error_code();
501 // If user requested binary then put stdout into binary mode if
503 if (!(Flags & sys::fs::F_Text))
504 sys::ChangeStdoutToBinary();
505 return STDOUT_FILENO;
509 EC = sys::fs::openFileForWrite(Filename, FD, Flags);
516 raw_fd_ostream::raw_fd_ostream(StringRef Filename, std::error_code &EC,
517 sys::fs::OpenFlags Flags)
518 : raw_fd_ostream(getFD(Filename, EC, Flags), true) {}
520 /// FD is the file descriptor that this writes to. If ShouldClose is true, this
521 /// closes the file when the stream is destroyed.
522 raw_fd_ostream::raw_fd_ostream(int fd, bool shouldClose, bool unbuffered)
523 : raw_pwrite_stream(unbuffered), FD(fd), ShouldClose(shouldClose),
524 Error(false), UseAtomicWrites(false) {
530 // Get the starting position.
531 off_t loc = ::lseek(FD, 0, SEEK_CUR);
533 // MSVCRT's _lseek(SEEK_CUR) doesn't return -1 for pipes.
534 sys::fs::file_status Status;
535 std::error_code EC = status(FD, Status);
536 SupportsSeeking = !EC && Status.type() == sys::fs::file_type::regular_file;
538 SupportsSeeking = loc != (off_t)-1;
540 if (!SupportsSeeking)
543 pos = static_cast<uint64_t>(loc);
546 raw_fd_ostream::~raw_fd_ostream() {
549 if (ShouldClose && sys::Process::SafelyCloseFileDescriptor(FD))
554 // On mingw, global dtors should not call exit().
555 // report_fatal_error() invokes exit(). We know report_fatal_error()
556 // might not write messages to stderr when any errors were detected
561 // If there are any pending errors, report them now. Clients wishing
562 // to avoid report_fatal_error calls should check for errors with
563 // has_error() and clear the error flag with clear_error() before
564 // destructing raw_ostream objects which may have errors.
566 report_fatal_error("IO failure on output stream.", /*GenCrashDiag=*/false);
570 void raw_fd_ostream::write_impl(const char *Ptr, size_t Size) {
571 assert(FD >= 0 && "File already closed.");
577 // Check whether we should attempt to use atomic writes.
578 if (LLVM_LIKELY(!UseAtomicWrites)) {
579 ret = ::write(FD, Ptr, Size);
581 // Use ::writev() where available.
582 #if defined(HAVE_WRITEV)
583 const void *Addr = static_cast<const void *>(Ptr);
584 struct iovec IOV = {const_cast<void *>(Addr), Size };
585 ret = ::writev(FD, &IOV, 1);
587 ret = ::write(FD, Ptr, Size);
592 // If it's a recoverable error, swallow it and retry the write.
594 // Ideally we wouldn't ever see EAGAIN or EWOULDBLOCK here, since
595 // raw_ostream isn't designed to do non-blocking I/O. However, some
596 // programs, such as old versions of bjam, have mistakenly used
597 // O_NONBLOCK. For compatibility, emulate blocking semantics by
598 // spinning until the write succeeds. If you don't want spinning,
599 // don't use O_NONBLOCK file descriptors with raw_ostream.
600 if (errno == EINTR || errno == EAGAIN
602 || errno == EWOULDBLOCK
607 // Otherwise it's a non-recoverable error. Note it and quit.
612 // The write may have written some or all of the data. Update the
613 // size and buffer pointer to reflect the remainder that needs
614 // to be written. If there are no bytes left, we're done.
620 void raw_fd_ostream::close() {
624 if (sys::Process::SafelyCloseFileDescriptor(FD))
629 uint64_t raw_fd_ostream::seek(uint64_t off) {
631 pos = ::lseek(FD, off, SEEK_SET);
632 if (pos == (uint64_t)-1)
637 void raw_fd_ostream::pwrite_impl(const char *Ptr, size_t Size,
639 uint64_t Pos = tell();
645 size_t raw_fd_ostream::preferred_buffer_size() const {
646 #if !defined(_MSC_VER) && !defined(__MINGW32__) && !defined(__minix)
647 // Windows and Minix have no st_blksize.
648 assert(FD >= 0 && "File not yet open!");
650 if (fstat(FD, &statbuf) != 0)
653 // If this is a terminal, don't use buffering. Line buffering
654 // would be a more traditional thing to do, but it's not worth
656 if (S_ISCHR(statbuf.st_mode) && isatty(FD))
658 // Return the preferred block size.
659 return statbuf.st_blksize;
661 return raw_ostream::preferred_buffer_size();
665 raw_ostream &raw_fd_ostream::changeColor(enum Colors colors, bool bold,
667 if (sys::Process::ColorNeedsFlush())
669 const char *colorcode =
670 (colors == SAVEDCOLOR) ? sys::Process::OutputBold(bg)
671 : sys::Process::OutputColor(colors, bold, bg);
673 size_t len = strlen(colorcode);
674 write(colorcode, len);
675 // don't account colors towards output characters
681 raw_ostream &raw_fd_ostream::resetColor() {
682 if (sys::Process::ColorNeedsFlush())
684 const char *colorcode = sys::Process::ResetColor();
686 size_t len = strlen(colorcode);
687 write(colorcode, len);
688 // don't account colors towards output characters
694 raw_ostream &raw_fd_ostream::reverseColor() {
695 if (sys::Process::ColorNeedsFlush())
697 const char *colorcode = sys::Process::OutputReverse();
699 size_t len = strlen(colorcode);
700 write(colorcode, len);
701 // don't account colors towards output characters
707 bool raw_fd_ostream::is_displayed() const {
708 return sys::Process::FileDescriptorIsDisplayed(FD);
711 bool raw_fd_ostream::has_colors() const {
712 return sys::Process::FileDescriptorHasColors(FD);
715 //===----------------------------------------------------------------------===//
716 // outs(), errs(), nulls()
717 //===----------------------------------------------------------------------===//
719 /// outs() - This returns a reference to a raw_ostream for standard output.
720 /// Use it like: outs() << "foo" << "bar";
721 raw_ostream &llvm::outs() {
722 // Set buffer settings to model stdout behavior.
723 // Delete the file descriptor when the program exits, forcing error
724 // detection. If you don't want this behavior, don't use outs().
726 static raw_fd_ostream S("-", EC, sys::fs::F_None);
731 /// errs() - This returns a reference to a raw_ostream for standard error.
732 /// Use it like: errs() << "foo" << "bar";
733 raw_ostream &llvm::errs() {
734 // Set standard error to be unbuffered by default.
735 static raw_fd_ostream S(STDERR_FILENO, false, true);
739 /// nulls() - This returns a reference to a raw_ostream which discards output.
740 raw_ostream &llvm::nulls() {
741 static raw_null_ostream S;
746 //===----------------------------------------------------------------------===//
747 // raw_string_ostream
748 //===----------------------------------------------------------------------===//
750 raw_string_ostream::~raw_string_ostream() {
754 void raw_string_ostream::write_impl(const char *Ptr, size_t Size) {
755 OS.append(Ptr, Size);
758 //===----------------------------------------------------------------------===//
759 // raw_svector_ostream
760 //===----------------------------------------------------------------------===//
762 uint64_t raw_svector_ostream::current_pos() const { return OS.size(); }
764 void raw_svector_ostream::write_impl(const char *Ptr, size_t Size) {
765 OS.append(Ptr, Ptr + Size);
768 void raw_svector_ostream::pwrite_impl(const char *Ptr, size_t Size,
770 memcpy(OS.data() + Offset, Ptr, Size);
773 //===----------------------------------------------------------------------===//
775 //===----------------------------------------------------------------------===//
777 raw_null_ostream::~raw_null_ostream() {
779 // ~raw_ostream asserts that the buffer is empty. This isn't necessary
780 // with raw_null_ostream, but it's better to have raw_null_ostream follow
781 // the rules than to change the rules just for raw_null_ostream.
786 void raw_null_ostream::write_impl(const char *Ptr, size_t Size) {
789 uint64_t raw_null_ostream::current_pos() const {
793 void raw_null_ostream::pwrite_impl(const char *Ptr, size_t Size,