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"
25 #include "llvm/Support/system_error.h"
30 #if defined(HAVE_UNISTD_H)
33 #if defined(HAVE_SYS_UIO_H) && defined(HAVE_WRITEV)
37 #if defined(__CYGWIN__)
44 # define STDIN_FILENO 0
47 # define STDOUT_FILENO 1
50 # define STDERR_FILENO 2
56 raw_ostream::~raw_ostream() {
57 // raw_ostream's subclasses should take care to flush the buffer
58 // in their destructors.
59 assert(OutBufCur == OutBufStart &&
60 "raw_ostream destructor called with non-empty buffer!");
62 if (BufferMode == InternalBuffer)
63 delete [] OutBufStart;
66 // An out of line virtual method to provide a home for the class vtable.
67 void raw_ostream::handle() {}
69 size_t raw_ostream::preferred_buffer_size() const {
70 // BUFSIZ is intended to be a reasonable default.
74 void raw_ostream::SetBuffered() {
75 // Ask the subclass to determine an appropriate buffer size.
76 if (size_t Size = preferred_buffer_size())
79 // It may return 0, meaning this stream should be unbuffered.
83 void raw_ostream::SetBufferAndMode(char *BufferStart, size_t Size,
85 assert(((Mode == Unbuffered && BufferStart == 0 && Size == 0) ||
86 (Mode != Unbuffered && BufferStart && Size)) &&
87 "stream must be unbuffered or have at least one byte");
88 // Make sure the current buffer is free of content (we can't flush here; the
89 // child buffer management logic will be in write_impl).
90 assert(GetNumBytesInBuffer() == 0 && "Current buffer is non-empty!");
92 if (BufferMode == InternalBuffer)
93 delete [] OutBufStart;
94 OutBufStart = BufferStart;
95 OutBufEnd = OutBufStart+Size;
96 OutBufCur = OutBufStart;
99 assert(OutBufStart <= OutBufEnd && "Invalid size!");
102 raw_ostream &raw_ostream::operator<<(unsigned long N) {
103 // Zero is a special case.
107 char NumberBuffer[20];
108 char *EndPtr = NumberBuffer+sizeof(NumberBuffer);
109 char *CurPtr = EndPtr;
112 *--CurPtr = '0' + char(N % 10);
115 return write(CurPtr, EndPtr-CurPtr);
118 raw_ostream &raw_ostream::operator<<(long N) {
121 // Avoid undefined behavior on LONG_MIN with a cast.
122 N = -(unsigned long)N;
125 return this->operator<<(static_cast<unsigned long>(N));
128 raw_ostream &raw_ostream::operator<<(unsigned long long N) {
129 // Output using 32-bit div/mod when possible.
130 if (N == static_cast<unsigned long>(N))
131 return this->operator<<(static_cast<unsigned long>(N));
133 char NumberBuffer[20];
134 char *EndPtr = NumberBuffer+sizeof(NumberBuffer);
135 char *CurPtr = EndPtr;
138 *--CurPtr = '0' + char(N % 10);
141 return write(CurPtr, EndPtr-CurPtr);
144 raw_ostream &raw_ostream::operator<<(long long N) {
147 // Avoid undefined behavior on INT64_MIN with a cast.
148 N = -(unsigned long long)N;
151 return this->operator<<(static_cast<unsigned long long>(N));
154 raw_ostream &raw_ostream::write_hex(unsigned long long N) {
155 // Zero is a special case.
159 char NumberBuffer[20];
160 char *EndPtr = NumberBuffer+sizeof(NumberBuffer);
161 char *CurPtr = EndPtr;
164 uintptr_t x = N % 16;
165 *--CurPtr = (x < 10 ? '0' + x : 'a' + x - 10);
169 return write(CurPtr, EndPtr-CurPtr);
172 raw_ostream &raw_ostream::write_escaped(StringRef Str,
173 bool UseHexEscapes) {
174 for (unsigned i = 0, e = Str.size(); i != e; ++i) {
175 unsigned char c = Str[i];
179 *this << '\\' << '\\';
182 *this << '\\' << 't';
185 *this << '\\' << 'n';
188 *this << '\\' << '"';
191 if (std::isprint(c)) {
196 // Write out the escaped representation.
198 *this << '\\' << 'x';
199 *this << hexdigit((c >> 4 & 0xF));
200 *this << hexdigit((c >> 0) & 0xF);
202 // Always use a full 3-character octal escape.
204 *this << char('0' + ((c >> 6) & 7));
205 *this << char('0' + ((c >> 3) & 7));
206 *this << char('0' + ((c >> 0) & 7));
214 raw_ostream &raw_ostream::operator<<(const void *P) {
217 return write_hex((uintptr_t) P);
220 raw_ostream &raw_ostream::operator<<(double N) {
222 // On MSVCRT and compatible, output of %e is incompatible to Posix
223 // by default. Number of exponent digits should be at least 2. "%+03d"
224 // FIXME: Implement our formatter to here or Support/Format.h!
225 int fpcl = _fpclass(N);
228 if (fpcl == _FPCLASS_NZ)
229 return *this << "-0.000000e+00";
233 len = snprintf(buf, sizeof(buf), "%e", N);
234 if (len <= sizeof(buf) - 2) {
235 if (len >= 5 && buf[len - 5] == 'e' && buf[len - 3] == '0') {
236 int cs = buf[len - 4];
237 if (cs == '+' || cs == '-') {
238 int c1 = buf[len - 2];
239 int c0 = buf[len - 1];
240 if (isdigit(static_cast<unsigned char>(c1)) &&
241 isdigit(static_cast<unsigned char>(c0))) {
242 // Trim leading '0': "...e+012" -> "...e+12\0"
249 return this->operator<<(buf);
252 return this->operator<<(format("%e", N));
257 void raw_ostream::flush_nonempty() {
258 assert(OutBufCur > OutBufStart && "Invalid call to flush_nonempty.");
259 size_t Length = OutBufCur - OutBufStart;
260 OutBufCur = OutBufStart;
261 write_impl(OutBufStart, Length);
264 raw_ostream &raw_ostream::write(unsigned char C) {
265 // Group exceptional cases into a single branch.
266 if (LLVM_UNLIKELY(OutBufCur >= OutBufEnd)) {
267 if (LLVM_UNLIKELY(!OutBufStart)) {
268 if (BufferMode == Unbuffered) {
269 write_impl(reinterpret_cast<char*>(&C), 1);
272 // Set up a buffer and start over.
284 raw_ostream &raw_ostream::write(const char *Ptr, size_t Size) {
285 // Group exceptional cases into a single branch.
286 if (LLVM_UNLIKELY(size_t(OutBufEnd - OutBufCur) < Size)) {
287 if (LLVM_UNLIKELY(!OutBufStart)) {
288 if (BufferMode == Unbuffered) {
289 write_impl(Ptr, Size);
292 // Set up a buffer and start over.
294 return write(Ptr, Size);
297 size_t NumBytes = OutBufEnd - OutBufCur;
299 // If the buffer is empty at this point we have a string that is larger
300 // than the buffer. Directly write the chunk that is a multiple of the
301 // preferred buffer size and put the remainder in the buffer.
302 if (LLVM_UNLIKELY(OutBufCur == OutBufStart)) {
303 size_t BytesToWrite = Size - (Size % NumBytes);
304 write_impl(Ptr, BytesToWrite);
305 size_t BytesRemaining = Size - BytesToWrite;
306 if (BytesRemaining > size_t(OutBufEnd - OutBufCur)) {
307 // Too much left over to copy into our buffer.
308 return write(Ptr + BytesToWrite, BytesRemaining);
310 copy_to_buffer(Ptr + BytesToWrite, BytesRemaining);
314 // We don't have enough space in the buffer to fit the string in. Insert as
315 // much as possible, flush and start over with the remainder.
316 copy_to_buffer(Ptr, NumBytes);
318 return write(Ptr + NumBytes, Size - NumBytes);
321 copy_to_buffer(Ptr, Size);
326 void raw_ostream::copy_to_buffer(const char *Ptr, size_t Size) {
327 assert(Size <= size_t(OutBufEnd - OutBufCur) && "Buffer overrun!");
329 // Handle short strings specially, memcpy isn't very good at very short
332 case 4: OutBufCur[3] = Ptr[3]; // FALL THROUGH
333 case 3: OutBufCur[2] = Ptr[2]; // FALL THROUGH
334 case 2: OutBufCur[1] = Ptr[1]; // FALL THROUGH
335 case 1: OutBufCur[0] = Ptr[0]; // FALL THROUGH
338 memcpy(OutBufCur, Ptr, Size);
346 raw_ostream &raw_ostream::operator<<(const format_object_base &Fmt) {
347 // If we have more than a few bytes left in our output buffer, try
348 // formatting directly onto its end.
349 size_t NextBufferSize = 127;
350 size_t BufferBytesLeft = OutBufEnd - OutBufCur;
351 if (BufferBytesLeft > 3) {
352 size_t BytesUsed = Fmt.print(OutBufCur, BufferBytesLeft);
354 // Common case is that we have plenty of space.
355 if (BytesUsed <= BufferBytesLeft) {
356 OutBufCur += BytesUsed;
360 // Otherwise, we overflowed and the return value tells us the size to try
362 NextBufferSize = BytesUsed;
365 // If we got here, we didn't have enough space in the output buffer for the
366 // string. Try printing into a SmallVector that is resized to have enough
367 // space. Iterate until we win.
368 SmallVector<char, 128> V;
371 V.resize(NextBufferSize);
373 // Try formatting into the SmallVector.
374 size_t BytesUsed = Fmt.print(V.data(), NextBufferSize);
376 // If BytesUsed fit into the vector, we win.
377 if (BytesUsed <= NextBufferSize)
378 return write(V.data(), BytesUsed);
380 // Otherwise, try again with a new size.
381 assert(BytesUsed > NextBufferSize && "Didn't grow buffer!?");
382 NextBufferSize = BytesUsed;
386 /// indent - Insert 'NumSpaces' spaces.
387 raw_ostream &raw_ostream::indent(unsigned NumSpaces) {
388 static const char Spaces[] = " "
392 // Usually the indentation is small, handle it with a fastpath.
393 if (NumSpaces < array_lengthof(Spaces))
394 return write(Spaces, NumSpaces);
397 unsigned NumToWrite = std::min(NumSpaces,
398 (unsigned)array_lengthof(Spaces)-1);
399 write(Spaces, NumToWrite);
400 NumSpaces -= NumToWrite;
406 //===----------------------------------------------------------------------===//
408 //===----------------------------------------------------------------------===//
410 // Out of line virtual method.
411 void format_object_base::home() {
414 //===----------------------------------------------------------------------===//
416 //===----------------------------------------------------------------------===//
418 /// raw_fd_ostream - Open the specified file for writing. If an error
419 /// occurs, information about the error is put into ErrorInfo, and the
420 /// stream should be immediately destroyed; the string will be empty
421 /// if no error occurred.
422 raw_fd_ostream::raw_fd_ostream(const char *Filename, std::string &ErrorInfo,
423 sys::fs::OpenFlags Flags)
424 : Error(false), UseAtomicWrites(false), pos(0) {
425 assert(Filename != 0 && "Filename is null");
428 // Handle "-" as stdout. Note that when we do this, we consider ourself
429 // the owner of stdout. This means that we can do things like close the
430 // file descriptor when we're done and set the "binary" flag globally.
431 if (Filename[0] == '-' && Filename[1] == 0) {
433 // If user requested binary then put stdout into binary mode if
435 if (Flags & sys::fs::F_Binary)
436 sys::ChangeStdoutToBinary();
437 // Close stdout when we're done, to detect any output errors.
442 error_code EC = sys::fs::openFileForWrite(Filename, FD, Flags);
445 ErrorInfo = "Error opening output file '" + std::string(Filename) + "'";
450 // Ok, we successfully opened the file, so it'll need to be closed.
454 /// raw_fd_ostream ctor - FD is the file descriptor that this writes to. If
455 /// ShouldClose is true, this closes the file when the stream is destroyed.
456 raw_fd_ostream::raw_fd_ostream(int fd, bool shouldClose, bool unbuffered)
457 : raw_ostream(unbuffered), FD(fd),
458 ShouldClose(shouldClose), Error(false), UseAtomicWrites(false) {
460 // Setting STDOUT and STDERR to binary mode is necessary in Win32
461 // to avoid undesirable linefeed conversion.
462 if (fd == STDOUT_FILENO || fd == STDERR_FILENO)
463 setmode(fd, O_BINARY);
466 // Get the starting position.
467 off_t loc = ::lseek(FD, 0, SEEK_CUR);
468 if (loc == (off_t)-1)
471 pos = static_cast<uint64_t>(loc);
474 raw_fd_ostream::~raw_fd_ostream() {
478 while (::close(FD) != 0)
479 if (errno != EINTR) {
486 // On mingw, global dtors should not call exit().
487 // report_fatal_error() invokes exit(). We know report_fatal_error()
488 // might not write messages to stderr when any errors were detected
493 // If there are any pending errors, report them now. Clients wishing
494 // to avoid report_fatal_error calls should check for errors with
495 // has_error() and clear the error flag with clear_error() before
496 // destructing raw_ostream objects which may have errors.
498 report_fatal_error("IO failure on output stream.", /*GenCrashDiag=*/false);
502 void raw_fd_ostream::write_impl(const char *Ptr, size_t Size) {
503 assert(FD >= 0 && "File already closed.");
509 // Check whether we should attempt to use atomic writes.
510 if (LLVM_LIKELY(!UseAtomicWrites)) {
511 ret = ::write(FD, Ptr, Size);
513 // Use ::writev() where available.
514 #if defined(HAVE_WRITEV)
515 const void *Addr = static_cast<const void *>(Ptr);
516 struct iovec IOV = {const_cast<void *>(Addr), Size };
517 ret = ::writev(FD, &IOV, 1);
519 ret = ::write(FD, Ptr, Size);
524 // If it's a recoverable error, swallow it and retry the write.
526 // Ideally we wouldn't ever see EAGAIN or EWOULDBLOCK here, since
527 // raw_ostream isn't designed to do non-blocking I/O. However, some
528 // programs, such as old versions of bjam, have mistakenly used
529 // O_NONBLOCK. For compatibility, emulate blocking semantics by
530 // spinning until the write succeeds. If you don't want spinning,
531 // don't use O_NONBLOCK file descriptors with raw_ostream.
532 if (errno == EINTR || errno == EAGAIN
534 || errno == EWOULDBLOCK
539 // Otherwise it's a non-recoverable error. Note it and quit.
544 // The write may have written some or all of the data. Update the
545 // size and buffer pointer to reflect the remainder that needs
546 // to be written. If there are no bytes left, we're done.
552 void raw_fd_ostream::close() {
556 while (::close(FD) != 0)
557 if (errno != EINTR) {
564 uint64_t raw_fd_ostream::seek(uint64_t off) {
566 pos = ::lseek(FD, off, SEEK_SET);
572 size_t raw_fd_ostream::preferred_buffer_size() const {
573 #if !defined(_MSC_VER) && !defined(__MINGW32__) && !defined(__minix)
574 // Windows and Minix have no st_blksize.
575 assert(FD >= 0 && "File not yet open!");
577 if (fstat(FD, &statbuf) != 0)
580 // If this is a terminal, don't use buffering. Line buffering
581 // would be a more traditional thing to do, but it's not worth
583 if (S_ISCHR(statbuf.st_mode) && isatty(FD))
585 // Return the preferred block size.
586 return statbuf.st_blksize;
588 return raw_ostream::preferred_buffer_size();
592 raw_ostream &raw_fd_ostream::changeColor(enum Colors colors, bool bold,
594 if (sys::Process::ColorNeedsFlush())
596 const char *colorcode =
597 (colors == SAVEDCOLOR) ? sys::Process::OutputBold(bg)
598 : sys::Process::OutputColor(colors, bold, bg);
600 size_t len = strlen(colorcode);
601 write(colorcode, len);
602 // don't account colors towards output characters
608 raw_ostream &raw_fd_ostream::resetColor() {
609 if (sys::Process::ColorNeedsFlush())
611 const char *colorcode = sys::Process::ResetColor();
613 size_t len = strlen(colorcode);
614 write(colorcode, len);
615 // don't account colors towards output characters
621 raw_ostream &raw_fd_ostream::reverseColor() {
622 if (sys::Process::ColorNeedsFlush())
624 const char *colorcode = sys::Process::OutputReverse();
626 size_t len = strlen(colorcode);
627 write(colorcode, len);
628 // don't account colors towards output characters
634 bool raw_fd_ostream::is_displayed() const {
635 return sys::Process::FileDescriptorIsDisplayed(FD);
638 bool raw_fd_ostream::has_colors() const {
639 return sys::Process::FileDescriptorHasColors(FD);
642 //===----------------------------------------------------------------------===//
643 // outs(), errs(), nulls()
644 //===----------------------------------------------------------------------===//
646 /// outs() - This returns a reference to a raw_ostream for standard output.
647 /// Use it like: outs() << "foo" << "bar";
648 raw_ostream &llvm::outs() {
649 // Set buffer settings to model stdout behavior.
650 // Delete the file descriptor when the program exists, forcing error
651 // detection. If you don't want this behavior, don't use outs().
652 static raw_fd_ostream S(STDOUT_FILENO, true);
656 /// errs() - This returns a reference to a raw_ostream for standard error.
657 /// Use it like: errs() << "foo" << "bar";
658 raw_ostream &llvm::errs() {
659 // Set standard error to be unbuffered by default.
660 static raw_fd_ostream S(STDERR_FILENO, false, true);
664 /// nulls() - This returns a reference to a raw_ostream which discards output.
665 raw_ostream &llvm::nulls() {
666 static raw_null_ostream S;
671 //===----------------------------------------------------------------------===//
672 // raw_string_ostream
673 //===----------------------------------------------------------------------===//
675 raw_string_ostream::~raw_string_ostream() {
679 void raw_string_ostream::write_impl(const char *Ptr, size_t Size) {
680 OS.append(Ptr, Size);
683 //===----------------------------------------------------------------------===//
684 // raw_svector_ostream
685 //===----------------------------------------------------------------------===//
687 // The raw_svector_ostream implementation uses the SmallVector itself as the
688 // buffer for the raw_ostream. We guarantee that the raw_ostream buffer is
689 // always pointing past the end of the vector, but within the vector
690 // capacity. This allows raw_ostream to write directly into the correct place,
691 // and we only need to set the vector size when the data is flushed.
693 raw_svector_ostream::raw_svector_ostream(SmallVectorImpl<char> &O) : OS(O) {
694 // Set up the initial external buffer. We make sure that the buffer has at
695 // least 128 bytes free; raw_ostream itself only requires 64, but we want to
696 // make sure that we don't grow the buffer unnecessarily on destruction (when
697 // the data is flushed). See the FIXME below.
698 OS.reserve(OS.size() + 128);
699 SetBuffer(OS.end(), OS.capacity() - OS.size());
702 raw_svector_ostream::~raw_svector_ostream() {
703 // FIXME: Prevent resizing during this flush().
707 /// resync - This is called when the SmallVector we're appending to is changed
708 /// outside of the raw_svector_ostream's control. It is only safe to do this
709 /// if the raw_svector_ostream has previously been flushed.
710 void raw_svector_ostream::resync() {
711 assert(GetNumBytesInBuffer() == 0 && "Didn't flush before mutating vector");
713 if (OS.capacity() - OS.size() < 64)
714 OS.reserve(OS.capacity() * 2);
715 SetBuffer(OS.end(), OS.capacity() - OS.size());
718 void raw_svector_ostream::write_impl(const char *Ptr, size_t Size) {
719 // If we're writing bytes from the end of the buffer into the smallvector, we
720 // don't need to copy the bytes, just commit the bytes because they are
721 // already in the right place.
722 if (Ptr == OS.end()) {
723 assert(OS.size() + Size <= OS.capacity() && "Invalid write_impl() call!");
724 OS.set_size(OS.size() + Size);
726 assert(GetNumBytesInBuffer() == 0 &&
727 "Should be writing from buffer if some bytes in it");
728 // Otherwise, do copy the bytes.
729 OS.append(Ptr, Ptr+Size);
732 // Grow the vector if necessary.
733 if (OS.capacity() - OS.size() < 64)
734 OS.reserve(OS.capacity() * 2);
736 // Update the buffer position.
737 SetBuffer(OS.end(), OS.capacity() - OS.size());
740 uint64_t raw_svector_ostream::current_pos() const {
744 StringRef raw_svector_ostream::str() {
746 return StringRef(OS.begin(), OS.size());
749 //===----------------------------------------------------------------------===//
751 //===----------------------------------------------------------------------===//
753 raw_null_ostream::~raw_null_ostream() {
755 // ~raw_ostream asserts that the buffer is empty. This isn't necessary
756 // with raw_null_ostream, but it's better to have raw_null_ostream follow
757 // the rules than to change the rules just for raw_null_ostream.
762 void raw_null_ostream::write_impl(const char *Ptr, size_t Size) {
765 uint64_t raw_null_ostream::current_pos() const {