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/Process.h"
24 #include "llvm/Support/Program.h"
28 #include <system_error>
30 // <fcntl.h> may provide O_BINARY.
31 #if defined(HAVE_FCNTL_H)
35 #if defined(HAVE_UNISTD_H)
38 #if defined(HAVE_SYS_UIO_H) && defined(HAVE_WRITEV)
42 #if defined(__CYGWIN__)
49 # define STDIN_FILENO 0
52 # define STDOUT_FILENO 1
55 # define STDERR_FILENO 2
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!");
67 if (BufferMode == InternalBuffer)
68 delete [] OutBufStart;
71 // An out of line virtual method to provide a home for the class vtable.
72 void raw_ostream::handle() {}
74 size_t raw_ostream::preferred_buffer_size() const {
75 // BUFSIZ is intended to be a reasonable default.
79 void raw_ostream::SetBuffered() {
80 // Ask the subclass to determine an appropriate buffer size.
81 if (size_t Size = preferred_buffer_size())
84 // It may return 0, meaning this stream should be unbuffered.
88 void raw_ostream::SetBufferAndMode(char *BufferStart, size_t Size,
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!");
97 if (BufferMode == InternalBuffer)
98 delete [] OutBufStart;
99 OutBufStart = BufferStart;
100 OutBufEnd = OutBufStart+Size;
101 OutBufCur = OutBufStart;
104 assert(OutBufStart <= OutBufEnd && "Invalid size!");
107 raw_ostream &raw_ostream::operator<<(unsigned long N) {
108 // Zero is a special case.
112 char NumberBuffer[20];
113 char *EndPtr = NumberBuffer+sizeof(NumberBuffer);
114 char *CurPtr = EndPtr;
117 *--CurPtr = '0' + char(N % 10);
120 return write(CurPtr, EndPtr-CurPtr);
123 raw_ostream &raw_ostream::operator<<(long N) {
126 // Avoid undefined behavior on LONG_MIN with a cast.
127 N = -(unsigned long)N;
130 return this->operator<<(static_cast<unsigned long>(N));
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));
138 char NumberBuffer[20];
139 char *EndPtr = NumberBuffer+sizeof(NumberBuffer);
140 char *CurPtr = EndPtr;
143 *--CurPtr = '0' + char(N % 10);
146 return write(CurPtr, EndPtr-CurPtr);
149 raw_ostream &raw_ostream::operator<<(long long N) {
152 // Avoid undefined behavior on INT64_MIN with a cast.
153 N = -(unsigned long long)N;
156 return this->operator<<(static_cast<unsigned long long>(N));
159 raw_ostream &raw_ostream::write_hex(unsigned long long N) {
160 // Zero is a special case.
164 char NumberBuffer[20];
165 char *EndPtr = NumberBuffer+sizeof(NumberBuffer);
166 char *CurPtr = EndPtr;
169 uintptr_t x = N % 16;
170 *--CurPtr = (x < 10 ? '0' + x : 'a' + x - 10);
174 return write(CurPtr, EndPtr-CurPtr);
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];
184 *this << '\\' << '\\';
187 *this << '\\' << 't';
190 *this << '\\' << 'n';
193 *this << '\\' << '"';
196 if (std::isprint(c)) {
201 // Write out the escaped representation.
203 *this << '\\' << 'x';
204 *this << hexdigit((c >> 4 & 0xF));
205 *this << hexdigit((c >> 0) & 0xF);
207 // Always use a full 3-character octal escape.
209 *this << char('0' + ((c >> 6) & 7));
210 *this << char('0' + ((c >> 3) & 7));
211 *this << char('0' + ((c >> 0) & 7));
219 raw_ostream &raw_ostream::operator<<(const void *P) {
222 return write_hex((uintptr_t) P);
225 raw_ostream &raw_ostream::operator<<(double N) {
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";
235 int fpcl = _fpclass(N);
238 if (fpcl == _FPCLASS_NZ)
239 return *this << "-0.000000e+00";
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"
260 return this->operator<<(buf);
263 return this->operator<<(format("%e", N));
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);
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);
283 // Set up a buffer and start over.
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);
303 // Set up a buffer and start over.
305 return write(Ptr, Size);
308 size_t NumBytes = OutBufEnd - OutBufCur;
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);
321 copy_to_buffer(Ptr + BytesToWrite, BytesRemaining);
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);
329 return write(Ptr + NumBytes, Size - NumBytes);
332 copy_to_buffer(Ptr, Size);
337 void raw_ostream::copy_to_buffer(const char *Ptr, size_t Size) {
338 assert(Size <= size_t(OutBufEnd - OutBufCur) && "Buffer overrun!");
340 // Handle short strings specially, memcpy isn't very good at very short
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
349 memcpy(OutBufCur, Ptr, Size);
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);
365 // Common case is that we have plenty of space.
366 if (BytesUsed <= BufferBytesLeft) {
367 OutBufCur += BytesUsed;
371 // Otherwise, we overflowed and the return value tells us the size to try
373 NextBufferSize = BytesUsed;
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;
382 V.resize(NextBufferSize);
384 // Try formatting into the SmallVector.
385 size_t BytesUsed = Fmt.print(V.data(), NextBufferSize);
387 // If BytesUsed fit into the vector, we win.
388 if (BytesUsed <= NextBufferSize)
389 return write(V.data(), BytesUsed);
391 // Otherwise, try again with a new size.
392 assert(BytesUsed > NextBufferSize && "Didn't grow buffer!?");
393 NextBufferSize = BytesUsed;
397 /// indent - Insert 'NumSpaces' spaces.
398 raw_ostream &raw_ostream::indent(unsigned NumSpaces) {
399 static const char Spaces[] = " "
403 // Usually the indentation is small, handle it with a fastpath.
404 if (NumSpaces < array_lengthof(Spaces))
405 return write(Spaces, NumSpaces);
408 unsigned NumToWrite = std::min(NumSpaces,
409 (unsigned)array_lengthof(Spaces)-1);
410 write(Spaces, NumToWrite);
411 NumSpaces -= NumToWrite;
417 //===----------------------------------------------------------------------===//
419 //===----------------------------------------------------------------------===//
421 // Out of line virtual method.
422 void format_object_base::home() {
425 //===----------------------------------------------------------------------===//
427 //===----------------------------------------------------------------------===//
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");
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) {
444 // If user requested binary then put stdout into binary mode if
446 if (!(Flags & sys::fs::F_Text))
447 sys::ChangeStdoutToBinary();
448 // Close stdout when we're done, to detect any output errors.
453 std::error_code EC = sys::fs::openFileForWrite(Filename, FD, Flags);
456 ErrorInfo = "Error opening output file '" + std::string(Filename) + "': " +
462 // Ok, we successfully opened the file, so it'll need to be closed.
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) {
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);
479 // Get the starting position.
480 off_t loc = ::lseek(FD, 0, SEEK_CUR);
481 if (loc == (off_t)-1)
484 pos = static_cast<uint64_t>(loc);
487 raw_fd_ostream::~raw_fd_ostream() {
491 while (::close(FD) != 0)
492 if (errno != EINTR) {
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
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.
511 report_fatal_error("IO failure on output stream.", /*GenCrashDiag=*/false);
515 void raw_fd_ostream::write_impl(const char *Ptr, size_t Size) {
516 assert(FD >= 0 && "File already closed.");
522 // Check whether we should attempt to use atomic writes.
523 if (LLVM_LIKELY(!UseAtomicWrites)) {
524 ret = ::write(FD, Ptr, Size);
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);
532 ret = ::write(FD, Ptr, Size);
537 // If it's a recoverable error, swallow it and retry the write.
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
547 || errno == EWOULDBLOCK
552 // Otherwise it's a non-recoverable error. Note it and quit.
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.
565 void raw_fd_ostream::close() {
569 while (::close(FD) != 0)
570 if (errno != EINTR) {
577 uint64_t raw_fd_ostream::seek(uint64_t off) {
579 pos = ::lseek(FD, off, SEEK_SET);
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!");
590 if (fstat(FD, &statbuf) != 0)
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
596 if (S_ISCHR(statbuf.st_mode) && isatty(FD))
598 // Return the preferred block size.
599 return statbuf.st_blksize;
601 return raw_ostream::preferred_buffer_size();
605 raw_ostream &raw_fd_ostream::changeColor(enum Colors colors, bool bold,
607 if (sys::Process::ColorNeedsFlush())
609 const char *colorcode =
610 (colors == SAVEDCOLOR) ? sys::Process::OutputBold(bg)
611 : sys::Process::OutputColor(colors, bold, bg);
613 size_t len = strlen(colorcode);
614 write(colorcode, len);
615 // don't account colors towards output characters
621 raw_ostream &raw_fd_ostream::resetColor() {
622 if (sys::Process::ColorNeedsFlush())
624 const char *colorcode = sys::Process::ResetColor();
626 size_t len = strlen(colorcode);
627 write(colorcode, len);
628 // don't account colors towards output characters
634 raw_ostream &raw_fd_ostream::reverseColor() {
635 if (sys::Process::ColorNeedsFlush())
637 const char *colorcode = sys::Process::OutputReverse();
639 size_t len = strlen(colorcode);
640 write(colorcode, len);
641 // don't account colors towards output characters
647 bool raw_fd_ostream::is_displayed() const {
648 return sys::Process::FileDescriptorIsDisplayed(FD);
651 bool raw_fd_ostream::has_colors() const {
652 return sys::Process::FileDescriptorHasColors(FD);
655 //===----------------------------------------------------------------------===//
656 // outs(), errs(), nulls()
657 //===----------------------------------------------------------------------===//
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);
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);
677 /// nulls() - This returns a reference to a raw_ostream which discards output.
678 raw_ostream &llvm::nulls() {
679 static raw_null_ostream S;
684 //===----------------------------------------------------------------------===//
685 // raw_string_ostream
686 //===----------------------------------------------------------------------===//
688 raw_string_ostream::~raw_string_ostream() {
692 void raw_string_ostream::write_impl(const char *Ptr, size_t Size) {
693 OS.append(Ptr, Size);
696 //===----------------------------------------------------------------------===//
697 // raw_svector_ostream
698 //===----------------------------------------------------------------------===//
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.
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());
715 raw_svector_ostream::~raw_svector_ostream() {
716 // FIXME: Prevent resizing during this flush().
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");
726 if (OS.capacity() - OS.size() < 64)
727 OS.reserve(OS.capacity() * 2);
728 SetBuffer(OS.end(), OS.capacity() - OS.size());
731 void raw_svector_ostream::write_impl(const char *Ptr, size_t Size) {
732 size_t NewSize = OS.size() + Size;
733 size_t NewReservation = NewSize + 64;
735 bool NoOverlap = Ptr + Size < OS.begin() || Ptr > OS.begin() + OS.capacity();
738 assert(!GetNumBytesInBuffer());
739 OS.reserve(NewReservation);
740 memcpy(OS.end(), Ptr, Size);
741 OS.set_size(NewSize);
742 } else if (Ptr == OS.end()) {
743 // Grow the buffer to include the scratch area without copying.
744 assert(NewSize <= OS.capacity() && "Invalid write_impl() call!");
745 OS.set_size(NewSize);
746 OS.reserve(NewReservation);
748 OS.append(Ptr, Ptr + Size);
749 OS.reserve(NewReservation);
752 SetBuffer(OS.end(), OS.capacity() - OS.size());
755 uint64_t raw_svector_ostream::current_pos() const {
759 StringRef raw_svector_ostream::str() {
761 return StringRef(OS.begin(), OS.size());
764 //===----------------------------------------------------------------------===//
766 //===----------------------------------------------------------------------===//
768 raw_null_ostream::~raw_null_ostream() {
770 // ~raw_ostream asserts that the buffer is empty. This isn't necessary
771 // with raw_null_ostream, but it's better to have raw_null_ostream follow
772 // the rules than to change the rules just for raw_null_ostream.
777 void raw_null_ostream::write_impl(const char *Ptr, size_t Size) {
780 uint64_t raw_null_ostream::current_pos() const {