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/Support/Format.h"
16 #include "llvm/Support/Program.h"
17 #include "llvm/Support/Process.h"
18 #include "llvm/ADT/StringExtras.h"
19 #include "llvm/ADT/SmallVector.h"
20 #include "llvm/Config/config.h"
21 #include "llvm/Support/Compiler.h"
22 #include "llvm/Support/ErrorHandling.h"
23 #include "llvm/ADT/STLExtras.h"
27 #include <sys/types.h>
29 #if defined(HAVE_UNISTD_H)
32 #if defined(HAVE_FCNTL_H)
35 #if defined(HAVE_SYS_UIO_H) && defined(HAVE_WRITEV)
39 #if defined(__CYGWIN__)
47 # define STDIN_FILENO 0
50 # define STDOUT_FILENO 1
53 # define STDERR_FILENO 2
59 raw_ostream::~raw_ostream() {
60 // raw_ostream's subclasses should take care to flush the buffer
61 // in their destructors.
62 assert(OutBufCur == OutBufStart &&
63 "raw_ostream destructor called with non-empty buffer!");
65 if (BufferMode == InternalBuffer)
66 delete [] OutBufStart;
69 // An out of line virtual method to provide a home for the class vtable.
70 void raw_ostream::handle() {}
72 size_t raw_ostream::preferred_buffer_size() const {
73 // BUFSIZ is intended to be a reasonable default.
77 void raw_ostream::SetBuffered() {
78 // Ask the subclass to determine an appropriate buffer size.
79 if (size_t Size = preferred_buffer_size())
82 // It may return 0, meaning this stream should be unbuffered.
86 void raw_ostream::SetBufferAndMode(char *BufferStart, size_t Size,
88 assert(((Mode == Unbuffered && BufferStart == 0 && Size == 0) ||
89 (Mode != Unbuffered && BufferStart && Size)) &&
90 "stream must be unbuffered or have at least one byte");
91 // Make sure the current buffer is free of content (we can't flush here; the
92 // child buffer management logic will be in write_impl).
93 assert(GetNumBytesInBuffer() == 0 && "Current buffer is non-empty!");
95 if (BufferMode == InternalBuffer)
96 delete [] OutBufStart;
97 OutBufStart = BufferStart;
98 OutBufEnd = OutBufStart+Size;
99 OutBufCur = OutBufStart;
102 assert(OutBufStart <= OutBufEnd && "Invalid size!");
105 raw_ostream &raw_ostream::operator<<(unsigned long N) {
106 // Zero is a special case.
110 char NumberBuffer[20];
111 char *EndPtr = NumberBuffer+sizeof(NumberBuffer);
112 char *CurPtr = EndPtr;
115 *--CurPtr = '0' + char(N % 10);
118 return write(CurPtr, EndPtr-CurPtr);
121 raw_ostream &raw_ostream::operator<<(long N) {
124 // Avoid undefined behavior on LONG_MIN with a cast.
125 N = -(unsigned long)N;
128 return this->operator<<(static_cast<unsigned long>(N));
131 raw_ostream &raw_ostream::operator<<(unsigned long long N) {
132 // Output using 32-bit div/mod when possible.
133 if (N == static_cast<unsigned long>(N))
134 return this->operator<<(static_cast<unsigned long>(N));
136 char NumberBuffer[20];
137 char *EndPtr = NumberBuffer+sizeof(NumberBuffer);
138 char *CurPtr = EndPtr;
141 *--CurPtr = '0' + char(N % 10);
144 return write(CurPtr, EndPtr-CurPtr);
147 raw_ostream &raw_ostream::operator<<(long long N) {
150 // Avoid undefined behavior on INT64_MIN with a cast.
151 N = -(unsigned long long)N;
154 return this->operator<<(static_cast<unsigned long long>(N));
157 raw_ostream &raw_ostream::write_hex(unsigned long long N) {
158 // Zero is a special case.
162 char NumberBuffer[20];
163 char *EndPtr = NumberBuffer+sizeof(NumberBuffer);
164 char *CurPtr = EndPtr;
167 uintptr_t x = N % 16;
168 *--CurPtr = (x < 10 ? '0' + x : 'a' + x - 10);
172 return write(CurPtr, EndPtr-CurPtr);
175 raw_ostream &raw_ostream::write_escaped(StringRef Str,
176 bool UseHexEscapes) {
177 for (unsigned i = 0, e = Str.size(); i != e; ++i) {
178 unsigned char c = Str[i];
182 *this << '\\' << '\\';
185 *this << '\\' << 't';
188 *this << '\\' << 'n';
191 *this << '\\' << '"';
194 if (std::isprint(c)) {
199 // Write out the escaped representation.
201 *this << '\\' << 'x';
202 *this << hexdigit((c >> 4 & 0xF));
203 *this << hexdigit((c >> 0) & 0xF);
205 // Always use a full 3-character octal escape.
207 *this << char('0' + ((c >> 6) & 7));
208 *this << char('0' + ((c >> 3) & 7));
209 *this << char('0' + ((c >> 0) & 7));
217 raw_ostream &raw_ostream::operator<<(const void *P) {
220 return write_hex((uintptr_t) P);
223 raw_ostream &raw_ostream::operator<<(double N) {
225 // On MSVCRT and compatible, output of %e is incompatible to Posix
226 // by default. Number of exponent digits should be at least 2. "%+03d"
227 // FIXME: Implement our formatter to here or Support/Format.h!
228 int fpcl = _fpclass(N);
231 if (fpcl == _FPCLASS_NZ)
232 return *this << "-0.000000e+00";
236 len = snprintf(buf, sizeof(buf), "%e", N);
237 if (len <= sizeof(buf) - 2) {
238 if (len >= 5 && buf[len - 5] == 'e' && buf[len - 3] == '0') {
239 int cs = buf[len - 4];
240 if (cs == '+' || cs == '-') {
241 int c1 = buf[len - 2];
242 int c0 = buf[len - 1];
243 if (isdigit(c1) && isdigit(c0)) {
244 // Trim leading '0': "...e+012" -> "...e+12\0"
251 return this->operator<<(buf);
254 return this->operator<<(format("%e", N));
259 void raw_ostream::flush_nonempty() {
260 assert(OutBufCur > OutBufStart && "Invalid call to flush_nonempty.");
261 size_t Length = OutBufCur - OutBufStart;
262 OutBufCur = OutBufStart;
263 write_impl(OutBufStart, Length);
266 raw_ostream &raw_ostream::write(unsigned char C) {
267 // Group exceptional cases into a single branch.
268 if (BUILTIN_EXPECT(OutBufCur >= OutBufEnd, false)) {
269 if (BUILTIN_EXPECT(!OutBufStart, false)) {
270 if (BufferMode == Unbuffered) {
271 write_impl(reinterpret_cast<char*>(&C), 1);
274 // Set up a buffer and start over.
286 raw_ostream &raw_ostream::write(const char *Ptr, size_t Size) {
287 // Group exceptional cases into a single branch.
288 if (BUILTIN_EXPECT(size_t(OutBufEnd - OutBufCur) < Size, false)) {
289 if (BUILTIN_EXPECT(!OutBufStart, false)) {
290 if (BufferMode == Unbuffered) {
291 write_impl(Ptr, Size);
294 // Set up a buffer and start over.
296 return write(Ptr, Size);
299 size_t NumBytes = OutBufEnd - OutBufCur;
301 // If the buffer is empty at this point we have a string that is larger
302 // than the buffer. Directly write the chunk that is a multiple of the
303 // preferred buffer size and put the remainder in the buffer.
304 if (BUILTIN_EXPECT(OutBufCur == OutBufStart, false)) {
305 size_t BytesToWrite = Size - (Size % NumBytes);
306 write_impl(Ptr, BytesToWrite);
307 copy_to_buffer(Ptr + BytesToWrite, Size - BytesToWrite);
311 // We don't have enough space in the buffer to fit the string in. Insert as
312 // much as possible, flush and start over with the remainder.
313 copy_to_buffer(Ptr, NumBytes);
315 return write(Ptr + NumBytes, Size - NumBytes);
318 copy_to_buffer(Ptr, Size);
323 void raw_ostream::copy_to_buffer(const char *Ptr, size_t Size) {
324 assert(Size <= size_t(OutBufEnd - OutBufCur) && "Buffer overrun!");
326 // Handle short strings specially, memcpy isn't very good at very short
329 case 4: OutBufCur[3] = Ptr[3]; // FALL THROUGH
330 case 3: OutBufCur[2] = Ptr[2]; // FALL THROUGH
331 case 2: OutBufCur[1] = Ptr[1]; // FALL THROUGH
332 case 1: OutBufCur[0] = Ptr[0]; // FALL THROUGH
335 memcpy(OutBufCur, Ptr, Size);
343 raw_ostream &raw_ostream::operator<<(const format_object_base &Fmt) {
344 // If we have more than a few bytes left in our output buffer, try
345 // formatting directly onto its end.
346 size_t NextBufferSize = 127;
347 size_t BufferBytesLeft = OutBufEnd - OutBufCur;
348 if (BufferBytesLeft > 3) {
349 size_t BytesUsed = Fmt.print(OutBufCur, BufferBytesLeft);
351 // Common case is that we have plenty of space.
352 if (BytesUsed <= BufferBytesLeft) {
353 OutBufCur += BytesUsed;
357 // Otherwise, we overflowed and the return value tells us the size to try
359 NextBufferSize = BytesUsed;
362 // If we got here, we didn't have enough space in the output buffer for the
363 // string. Try printing into a SmallVector that is resized to have enough
364 // space. Iterate until we win.
365 SmallVector<char, 128> V;
368 V.resize(NextBufferSize);
370 // Try formatting into the SmallVector.
371 size_t BytesUsed = Fmt.print(V.data(), NextBufferSize);
373 // If BytesUsed fit into the vector, we win.
374 if (BytesUsed <= NextBufferSize)
375 return write(V.data(), BytesUsed);
377 // Otherwise, try again with a new size.
378 assert(BytesUsed > NextBufferSize && "Didn't grow buffer!?");
379 NextBufferSize = BytesUsed;
383 /// indent - Insert 'NumSpaces' spaces.
384 raw_ostream &raw_ostream::indent(unsigned NumSpaces) {
385 static const char Spaces[] = " "
389 // Usually the indentation is small, handle it with a fastpath.
390 if (NumSpaces < array_lengthof(Spaces))
391 return write(Spaces, NumSpaces);
394 unsigned NumToWrite = std::min(NumSpaces,
395 (unsigned)array_lengthof(Spaces)-1);
396 write(Spaces, NumToWrite);
397 NumSpaces -= NumToWrite;
403 //===----------------------------------------------------------------------===//
405 //===----------------------------------------------------------------------===//
407 // Out of line virtual method.
408 void format_object_base::home() {
411 //===----------------------------------------------------------------------===//
413 //===----------------------------------------------------------------------===//
415 /// raw_fd_ostream - Open the specified file for writing. If an error
416 /// occurs, information about the error is put into ErrorInfo, and the
417 /// stream should be immediately destroyed; the string will be empty
418 /// if no error occurred.
419 raw_fd_ostream::raw_fd_ostream(const char *Filename, std::string &ErrorInfo,
421 : Error(false), UseAtomicWrites(false), pos(0)
423 assert(Filename != 0 && "Filename is null");
424 // Verify that we don't have both "append" and "excl".
425 assert((!(Flags & F_Excl) || !(Flags & F_Append)) &&
426 "Cannot specify both 'excl' and 'append' file creation flags!");
430 // Handle "-" as stdout. Note that when we do this, we consider ourself
431 // the owner of stdout. This means that we can do things like close the
432 // file descriptor when we're done and set the "binary" flag globally.
433 if (Filename[0] == '-' && Filename[1] == 0) {
435 // If user requested binary then put stdout into binary mode if
437 if (Flags & F_Binary)
438 sys::Program::ChangeStdoutToBinary();
439 // Close stdout when we're done, to detect any output errors.
444 int OpenFlags = O_WRONLY|O_CREAT;
446 if (Flags & F_Binary)
447 OpenFlags |= O_BINARY;
450 if (Flags & F_Append)
451 OpenFlags |= O_APPEND;
453 OpenFlags |= O_TRUNC;
457 while ((FD = open(Filename, OpenFlags, 0664)) < 0) {
458 if (errno != EINTR) {
459 ErrorInfo = "Error opening output file '" + std::string(Filename) + "'";
465 // Ok, we successfully opened the file, so it'll need to be closed.
469 /// raw_fd_ostream ctor - FD is the file descriptor that this writes to. If
470 /// ShouldClose is true, this closes the file when the stream is destroyed.
471 raw_fd_ostream::raw_fd_ostream(int fd, bool shouldClose, bool unbuffered)
472 : raw_ostream(unbuffered), FD(fd),
473 ShouldClose(shouldClose), Error(false), UseAtomicWrites(false) {
475 // Setting STDOUT and STDERR to binary mode is necessary in Win32
476 // to avoid undesirable linefeed conversion.
477 if (fd == STDOUT_FILENO || fd == STDERR_FILENO)
478 setmode(fd, O_BINARY);
481 // Get the starting position.
482 off_t loc = ::lseek(FD, 0, SEEK_CUR);
483 if (loc == (off_t)-1)
486 pos = static_cast<uint64_t>(loc);
489 raw_fd_ostream::~raw_fd_ostream() {
493 while (::close(FD) != 0)
494 if (errno != EINTR) {
501 // On mingw, global dtors should not call exit().
502 // report_fatal_error() invokes exit(). We know report_fatal_error()
503 // might not write messages to stderr when any errors were detected
508 // If there are any pending errors, report them now. Clients wishing
509 // to avoid report_fatal_error calls should check for errors with
510 // has_error() and clear the error flag with clear_error() before
511 // destructing raw_ostream objects which may have errors.
513 report_fatal_error("IO failure on output stream.");
517 void raw_fd_ostream::write_impl(const char *Ptr, size_t Size) {
518 assert(FD >= 0 && "File already closed.");
524 // Check whether we should attempt to use atomic writes.
525 if (BUILTIN_EXPECT(!UseAtomicWrites, true)) {
526 ret = ::write(FD, Ptr, Size);
528 // Use ::writev() where available.
529 #if defined(HAVE_WRITEV)
530 struct iovec IOV = { (void*) Ptr, Size };
531 ret = ::writev(FD, &IOV, 1);
533 ret = ::write(FD, Ptr, Size);
538 // If it's a recoverable error, swallow it and retry the write.
540 // Ideally we wouldn't ever see EAGAIN or EWOULDBLOCK here, since
541 // raw_ostream isn't designed to do non-blocking I/O. However, some
542 // programs, such as old versions of bjam, have mistakenly used
543 // O_NONBLOCK. For compatibility, emulate blocking semantics by
544 // spinning until the write succeeds. If you don't want spinning,
545 // don't use O_NONBLOCK file descriptors with raw_ostream.
546 if (errno == EINTR || errno == EAGAIN
548 || errno == EWOULDBLOCK
553 // Otherwise it's a non-recoverable error. Note it and quit.
558 // The write may have written some or all of the data. Update the
559 // size and buffer pointer to reflect the remainder that needs
560 // to be written. If there are no bytes left, we're done.
566 void raw_fd_ostream::close() {
570 while (::close(FD) != 0)
571 if (errno != EINTR) {
578 uint64_t raw_fd_ostream::seek(uint64_t off) {
580 pos = ::lseek(FD, off, SEEK_SET);
586 size_t raw_fd_ostream::preferred_buffer_size() const {
587 #if !defined(_MSC_VER) && !defined(__MINGW32__) && !defined(__minix)
588 // Windows and Minix have no st_blksize.
589 assert(FD >= 0 && "File not yet open!");
591 if (fstat(FD, &statbuf) != 0)
594 // If this is a terminal, don't use buffering. Line buffering
595 // would be a more traditional thing to do, but it's not worth
597 if (S_ISCHR(statbuf.st_mode) && isatty(FD))
599 // Return the preferred block size.
600 return statbuf.st_blksize;
602 return raw_ostream::preferred_buffer_size();
606 raw_ostream &raw_fd_ostream::changeColor(enum Colors colors, bool bold,
608 if (sys::Process::ColorNeedsFlush())
610 const char *colorcode =
611 (colors == SAVEDCOLOR) ? sys::Process::OutputBold(bg)
612 : sys::Process::OutputColor(colors, bold, bg);
614 size_t len = strlen(colorcode);
615 write(colorcode, len);
616 // don't account colors towards output characters
622 raw_ostream &raw_fd_ostream::resetColor() {
623 if (sys::Process::ColorNeedsFlush())
625 const char *colorcode = sys::Process::ResetColor();
627 size_t len = strlen(colorcode);
628 write(colorcode, len);
629 // don't account colors towards output characters
635 bool raw_fd_ostream::is_displayed() const {
636 return sys::Process::FileDescriptorIsDisplayed(FD);
639 //===----------------------------------------------------------------------===//
640 // outs(), errs(), nulls()
641 //===----------------------------------------------------------------------===//
643 /// outs() - This returns a reference to a raw_ostream for standard output.
644 /// Use it like: outs() << "foo" << "bar";
645 raw_ostream &llvm::outs() {
646 // Set buffer settings to model stdout behavior.
647 // Delete the file descriptor when the program exists, forcing error
648 // detection. If you don't want this behavior, don't use outs().
649 static raw_fd_ostream S(STDOUT_FILENO, true);
653 /// errs() - This returns a reference to a raw_ostream for standard error.
654 /// Use it like: errs() << "foo" << "bar";
655 raw_ostream &llvm::errs() {
656 // Set standard error to be unbuffered by default.
657 static raw_fd_ostream S(STDERR_FILENO, false, true);
661 /// nulls() - This returns a reference to a raw_ostream which discards output.
662 raw_ostream &llvm::nulls() {
663 static raw_null_ostream S;
668 //===----------------------------------------------------------------------===//
669 // raw_string_ostream
670 //===----------------------------------------------------------------------===//
672 raw_string_ostream::~raw_string_ostream() {
676 void raw_string_ostream::write_impl(const char *Ptr, size_t Size) {
677 OS.append(Ptr, Size);
680 //===----------------------------------------------------------------------===//
681 // raw_svector_ostream
682 //===----------------------------------------------------------------------===//
684 // The raw_svector_ostream implementation uses the SmallVector itself as the
685 // buffer for the raw_ostream. We guarantee that the raw_ostream buffer is
686 // always pointing past the end of the vector, but within the vector
687 // capacity. This allows raw_ostream to write directly into the correct place,
688 // and we only need to set the vector size when the data is flushed.
690 raw_svector_ostream::raw_svector_ostream(SmallVectorImpl<char> &O) : OS(O) {
691 // Set up the initial external buffer. We make sure that the buffer has at
692 // least 128 bytes free; raw_ostream itself only requires 64, but we want to
693 // make sure that we don't grow the buffer unnecessarily on destruction (when
694 // the data is flushed). See the FIXME below.
695 OS.reserve(OS.size() + 128);
696 SetBuffer(OS.end(), OS.capacity() - OS.size());
699 raw_svector_ostream::~raw_svector_ostream() {
700 // FIXME: Prevent resizing during this flush().
704 /// resync - This is called when the SmallVector we're appending to is changed
705 /// outside of the raw_svector_ostream's control. It is only safe to do this
706 /// if the raw_svector_ostream has previously been flushed.
707 void raw_svector_ostream::resync() {
708 assert(GetNumBytesInBuffer() == 0 && "Didn't flush before mutating vector");
710 if (OS.capacity() - OS.size() < 64)
711 OS.reserve(OS.capacity() * 2);
712 SetBuffer(OS.end(), OS.capacity() - OS.size());
715 void raw_svector_ostream::write_impl(const char *Ptr, size_t Size) {
716 // If we're writing bytes from the end of the buffer into the smallvector, we
717 // don't need to copy the bytes, just commit the bytes because they are
718 // already in the right place.
719 if (Ptr == OS.end()) {
720 assert(OS.size() + Size <= OS.capacity() && "Invalid write_impl() call!");
721 OS.set_size(OS.size() + Size);
723 assert(GetNumBytesInBuffer() == 0 &&
724 "Should be writing from buffer if some bytes in it");
725 // Otherwise, do copy the bytes.
726 OS.append(Ptr, Ptr+Size);
729 // Grow the vector if necessary.
730 if (OS.capacity() - OS.size() < 64)
731 OS.reserve(OS.capacity() * 2);
733 // Update the buffer position.
734 SetBuffer(OS.end(), OS.capacity() - OS.size());
737 uint64_t raw_svector_ostream::current_pos() const {
741 StringRef raw_svector_ostream::str() {
743 return StringRef(OS.begin(), OS.size());
746 //===----------------------------------------------------------------------===//
748 //===----------------------------------------------------------------------===//
750 raw_null_ostream::~raw_null_ostream() {
752 // ~raw_ostream asserts that the buffer is empty. This isn't necessary
753 // with raw_null_ostream, but it's better to have raw_null_ostream follow
754 // the rules than to change the rules just for raw_null_ostream.
759 void raw_null_ostream::write_impl(const char *Ptr, size_t Size) {
762 uint64_t raw_null_ostream::current_pos() const {