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::raw_fd_ostream(StringRef Filename, std::error_code &EC,
430 sys::fs::OpenFlags Flags)
431 : Error(false), UseAtomicWrites(false), pos(0) {
432 EC = std::error_code();
433 // Handle "-" as stdout. Note that when we do this, we consider ourself
434 // the owner of stdout. This means that we can do things like close the
435 // file descriptor when we're done and set the "binary" flag globally.
436 if (Filename == "-") {
438 // If user requested binary then put stdout into binary mode if
440 if (!(Flags & sys::fs::F_Text))
441 sys::ChangeStdoutToBinary();
442 // Close stdout when we're done, to detect any output errors.
447 EC = sys::fs::openFileForWrite(Filename, FD, Flags);
454 // Ok, we successfully opened the file, so it'll need to be closed.
458 /// raw_fd_ostream ctor - FD is the file descriptor that this writes to. If
459 /// ShouldClose is true, this closes the file when the stream is destroyed.
460 raw_fd_ostream::raw_fd_ostream(int fd, bool shouldClose, bool unbuffered)
461 : raw_ostream(unbuffered), FD(fd),
462 ShouldClose(shouldClose), Error(false), UseAtomicWrites(false) {
464 // Setting STDOUT to binary mode is necessary in Win32
465 // to avoid undesirable linefeed conversion.
466 // Don't touch STDERR, or w*printf() (in assert()) would barf wide chars.
467 if (fd == STDOUT_FILENO)
468 setmode(fd, O_BINARY);
471 // Get the starting position.
472 off_t loc = ::lseek(FD, 0, SEEK_CUR);
473 if (loc == (off_t)-1)
476 pos = static_cast<uint64_t>(loc);
479 raw_fd_ostream::~raw_fd_ostream() {
483 while (::close(FD) != 0)
484 if (errno != EINTR) {
491 // On mingw, global dtors should not call exit().
492 // report_fatal_error() invokes exit(). We know report_fatal_error()
493 // might not write messages to stderr when any errors were detected
498 // If there are any pending errors, report them now. Clients wishing
499 // to avoid report_fatal_error calls should check for errors with
500 // has_error() and clear the error flag with clear_error() before
501 // destructing raw_ostream objects which may have errors.
503 report_fatal_error("IO failure on output stream.", /*GenCrashDiag=*/false);
507 void raw_fd_ostream::write_impl(const char *Ptr, size_t Size) {
508 assert(FD >= 0 && "File already closed.");
514 // Check whether we should attempt to use atomic writes.
515 if (LLVM_LIKELY(!UseAtomicWrites)) {
516 ret = ::write(FD, Ptr, Size);
518 // Use ::writev() where available.
519 #if defined(HAVE_WRITEV)
520 const void *Addr = static_cast<const void *>(Ptr);
521 struct iovec IOV = {const_cast<void *>(Addr), Size };
522 ret = ::writev(FD, &IOV, 1);
524 ret = ::write(FD, Ptr, Size);
529 // If it's a recoverable error, swallow it and retry the write.
531 // Ideally we wouldn't ever see EAGAIN or EWOULDBLOCK here, since
532 // raw_ostream isn't designed to do non-blocking I/O. However, some
533 // programs, such as old versions of bjam, have mistakenly used
534 // O_NONBLOCK. For compatibility, emulate blocking semantics by
535 // spinning until the write succeeds. If you don't want spinning,
536 // don't use O_NONBLOCK file descriptors with raw_ostream.
537 if (errno == EINTR || errno == EAGAIN
539 || errno == EWOULDBLOCK
544 // Otherwise it's a non-recoverable error. Note it and quit.
549 // The write may have written some or all of the data. Update the
550 // size and buffer pointer to reflect the remainder that needs
551 // to be written. If there are no bytes left, we're done.
557 void raw_fd_ostream::close() {
561 while (::close(FD) != 0)
562 if (errno != EINTR) {
569 uint64_t raw_fd_ostream::seek(uint64_t off) {
571 pos = ::lseek(FD, off, SEEK_SET);
577 size_t raw_fd_ostream::preferred_buffer_size() const {
578 #if !defined(_MSC_VER) && !defined(__MINGW32__) && !defined(__minix)
579 // Windows and Minix have no st_blksize.
580 assert(FD >= 0 && "File not yet open!");
582 if (fstat(FD, &statbuf) != 0)
585 // If this is a terminal, don't use buffering. Line buffering
586 // would be a more traditional thing to do, but it's not worth
588 if (S_ISCHR(statbuf.st_mode) && isatty(FD))
590 // Return the preferred block size.
591 return statbuf.st_blksize;
593 return raw_ostream::preferred_buffer_size();
597 raw_ostream &raw_fd_ostream::changeColor(enum Colors colors, bool bold,
599 if (sys::Process::ColorNeedsFlush())
601 const char *colorcode =
602 (colors == SAVEDCOLOR) ? sys::Process::OutputBold(bg)
603 : sys::Process::OutputColor(colors, bold, bg);
605 size_t len = strlen(colorcode);
606 write(colorcode, len);
607 // don't account colors towards output characters
613 raw_ostream &raw_fd_ostream::resetColor() {
614 if (sys::Process::ColorNeedsFlush())
616 const char *colorcode = sys::Process::ResetColor();
618 size_t len = strlen(colorcode);
619 write(colorcode, len);
620 // don't account colors towards output characters
626 raw_ostream &raw_fd_ostream::reverseColor() {
627 if (sys::Process::ColorNeedsFlush())
629 const char *colorcode = sys::Process::OutputReverse();
631 size_t len = strlen(colorcode);
632 write(colorcode, len);
633 // don't account colors towards output characters
639 bool raw_fd_ostream::is_displayed() const {
640 return sys::Process::FileDescriptorIsDisplayed(FD);
643 bool raw_fd_ostream::has_colors() const {
644 return sys::Process::FileDescriptorHasColors(FD);
647 //===----------------------------------------------------------------------===//
648 // outs(), errs(), nulls()
649 //===----------------------------------------------------------------------===//
651 /// outs() - This returns a reference to a raw_ostream for standard output.
652 /// Use it like: outs() << "foo" << "bar";
653 raw_ostream &llvm::outs() {
654 // Set buffer settings to model stdout behavior.
655 // Delete the file descriptor when the program exits, forcing error
656 // detection. If you don't want this behavior, don't use outs().
657 static raw_fd_ostream S(STDOUT_FILENO, true);
661 /// errs() - This returns a reference to a raw_ostream for standard error.
662 /// Use it like: errs() << "foo" << "bar";
663 raw_ostream &llvm::errs() {
664 // Set standard error to be unbuffered by default.
665 static raw_fd_ostream S(STDERR_FILENO, false, true);
669 /// nulls() - This returns a reference to a raw_ostream which discards output.
670 raw_ostream &llvm::nulls() {
671 static raw_null_ostream S;
676 //===----------------------------------------------------------------------===//
677 // raw_string_ostream
678 //===----------------------------------------------------------------------===//
680 raw_string_ostream::~raw_string_ostream() {
684 void raw_string_ostream::write_impl(const char *Ptr, size_t Size) {
685 OS.append(Ptr, Size);
688 //===----------------------------------------------------------------------===//
689 // raw_svector_ostream
690 //===----------------------------------------------------------------------===//
692 // The raw_svector_ostream implementation uses the SmallVector itself as the
693 // buffer for the raw_ostream. We guarantee that the raw_ostream buffer is
694 // always pointing past the end of the vector, but within the vector
695 // capacity. This allows raw_ostream to write directly into the correct place,
696 // and we only need to set the vector size when the data is flushed.
698 raw_svector_ostream::raw_svector_ostream(SmallVectorImpl<char> &O) : OS(O) {
699 // Set up the initial external buffer. We make sure that the buffer has at
700 // least 128 bytes free; raw_ostream itself only requires 64, but we want to
701 // make sure that we don't grow the buffer unnecessarily on destruction (when
702 // the data is flushed). See the FIXME below.
703 OS.reserve(OS.size() + 128);
704 SetBuffer(OS.end(), OS.capacity() - OS.size());
707 raw_svector_ostream::~raw_svector_ostream() {
708 // FIXME: Prevent resizing during this flush().
712 /// resync - This is called when the SmallVector we're appending to is changed
713 /// outside of the raw_svector_ostream's control. It is only safe to do this
714 /// if the raw_svector_ostream has previously been flushed.
715 void raw_svector_ostream::resync() {
716 assert(GetNumBytesInBuffer() == 0 && "Didn't flush before mutating vector");
718 if (OS.capacity() - OS.size() < 64)
719 OS.reserve(OS.capacity() * 2);
720 SetBuffer(OS.end(), OS.capacity() - OS.size());
723 void raw_svector_ostream::write_impl(const char *Ptr, size_t Size) {
724 if (Ptr == OS.end()) {
725 // Grow the buffer to include the scratch area without copying.
726 size_t NewSize = OS.size() + Size;
727 assert(NewSize <= OS.capacity() && "Invalid write_impl() call!");
728 OS.set_size(NewSize);
730 assert(!GetNumBytesInBuffer());
731 OS.append(Ptr, Ptr + Size);
734 OS.reserve(OS.size() + 64);
735 SetBuffer(OS.end(), OS.capacity() - OS.size());
738 uint64_t raw_svector_ostream::current_pos() const {
742 StringRef raw_svector_ostream::str() {
744 return StringRef(OS.begin(), OS.size());
747 //===----------------------------------------------------------------------===//
749 //===----------------------------------------------------------------------===//
751 raw_null_ostream::~raw_null_ostream() {
753 // ~raw_ostream asserts that the buffer is empty. This isn't necessary
754 // with raw_null_ostream, but it's better to have raw_null_ostream follow
755 // the rules than to change the rules just for raw_null_ostream.
760 void raw_null_ostream::write_impl(const char *Ptr, size_t Size) {
763 uint64_t raw_null_ostream::current_pos() const {