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/System/Program.h"
17 #include "llvm/System/Process.h"
18 #include "llvm/ADT/SmallVector.h"
19 #include "llvm/Config/config.h"
20 #include "llvm/Support/Compiler.h"
21 #include "llvm/Support/ErrorHandling.h"
22 #include "llvm/ADT/STLExtras.h"
26 #include <sys/types.h>
28 #if defined(HAVE_UNISTD_H)
31 #if defined(HAVE_FCNTL_H)
39 # define STDIN_FILENO 0
42 # define STDOUT_FILENO 1
45 # define STDERR_FILENO 2
51 raw_ostream::~raw_ostream() {
52 // raw_ostream's subclasses should take care to flush the buffer
53 // in their destructors.
54 assert(OutBufCur == OutBufStart &&
55 "raw_ostream destructor called with non-empty buffer!");
57 if (BufferMode == InternalBuffer)
58 delete [] OutBufStart;
60 // If there are any pending errors, report them now. Clients wishing
61 // to avoid report_fatal_error calls should check for errors with
62 // has_error() and clear the error flag with clear_error() before
63 // destructing raw_ostream objects which may have errors.
65 report_fatal_error("IO failure on output stream.");
68 // An out of line virtual method to provide a home for the class vtable.
69 void raw_ostream::handle() {}
71 size_t raw_ostream::preferred_buffer_size() const {
72 // BUFSIZ is intended to be a reasonable default.
76 void raw_ostream::SetBuffered() {
77 // Ask the subclass to determine an appropriate buffer size.
78 if (size_t Size = preferred_buffer_size())
81 // It may return 0, meaning this stream should be unbuffered.
85 void raw_ostream::SetBufferAndMode(char *BufferStart, size_t Size,
87 assert(((Mode == Unbuffered && BufferStart == 0 && Size == 0) ||
88 (Mode != Unbuffered && BufferStart && Size)) &&
89 "stream must be unbuffered or have at least one byte");
90 // Make sure the current buffer is free of content (we can't flush here; the
91 // child buffer management logic will be in write_impl).
92 assert(GetNumBytesInBuffer() == 0 && "Current buffer is non-empty!");
94 if (BufferMode == InternalBuffer)
95 delete [] OutBufStart;
96 OutBufStart = BufferStart;
97 OutBufEnd = OutBufStart+Size;
98 OutBufCur = OutBufStart;
101 assert(OutBufStart <= OutBufEnd && "Invalid size!");
104 raw_ostream &raw_ostream::operator<<(unsigned long N) {
105 // Zero is a special case.
109 char NumberBuffer[20];
110 char *EndPtr = NumberBuffer+sizeof(NumberBuffer);
111 char *CurPtr = EndPtr;
114 *--CurPtr = '0' + char(N % 10);
117 return write(CurPtr, EndPtr-CurPtr);
120 raw_ostream &raw_ostream::operator<<(long N) {
126 return this->operator<<(static_cast<unsigned long>(N));
129 raw_ostream &raw_ostream::operator<<(unsigned long long N) {
130 // Output using 32-bit div/mod when possible.
131 if (N == static_cast<unsigned long>(N))
132 return this->operator<<(static_cast<unsigned long>(N));
134 char NumberBuffer[20];
135 char *EndPtr = NumberBuffer+sizeof(NumberBuffer);
136 char *CurPtr = EndPtr;
139 *--CurPtr = '0' + char(N % 10);
142 return write(CurPtr, EndPtr-CurPtr);
145 raw_ostream &raw_ostream::operator<<(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 for (unsigned i = 0, e = Str.size(); i != e; ++i) {
174 unsigned char c = Str[i];
178 *this << '\\' << '\\';
181 *this << '\\' << 't';
184 *this << '\\' << 'n';
187 *this << '\\' << '"';
190 if (std::isprint(c)) {
195 // Always expand to a 3-character octal escape.
197 *this << char('0' + ((c >> 6) & 7));
198 *this << char('0' + ((c >> 3) & 7));
199 *this << char('0' + ((c >> 0) & 7));
206 raw_ostream &raw_ostream::operator<<(const void *P) {
209 return write_hex((uintptr_t) P);
212 raw_ostream &raw_ostream::operator<<(double N) {
213 return this->operator<<(format("%e", N));
218 void raw_ostream::flush_nonempty() {
219 assert(OutBufCur > OutBufStart && "Invalid call to flush_nonempty.");
220 size_t Length = OutBufCur - OutBufStart;
221 OutBufCur = OutBufStart;
222 write_impl(OutBufStart, Length);
225 raw_ostream &raw_ostream::write(unsigned char C) {
226 // Group exceptional cases into a single branch.
227 if (BUILTIN_EXPECT(OutBufCur >= OutBufEnd, false)) {
228 if (BUILTIN_EXPECT(!OutBufStart, false)) {
229 if (BufferMode == Unbuffered) {
230 write_impl(reinterpret_cast<char*>(&C), 1);
233 // Set up a buffer and start over.
245 raw_ostream &raw_ostream::write(const char *Ptr, size_t Size) {
246 // Group exceptional cases into a single branch.
247 if (BUILTIN_EXPECT(OutBufCur+Size > OutBufEnd, false)) {
248 if (BUILTIN_EXPECT(!OutBufStart, false)) {
249 if (BufferMode == Unbuffered) {
250 write_impl(Ptr, Size);
253 // Set up a buffer and start over.
255 return write(Ptr, Size);
258 // Write out the data in buffer-sized blocks until the remainder
259 // fits within the buffer.
261 size_t NumBytes = OutBufEnd - OutBufCur;
262 copy_to_buffer(Ptr, NumBytes);
266 } while (OutBufCur+Size > OutBufEnd);
269 copy_to_buffer(Ptr, Size);
274 void raw_ostream::copy_to_buffer(const char *Ptr, size_t Size) {
275 assert(Size <= size_t(OutBufEnd - OutBufCur) && "Buffer overrun!");
277 // Handle short strings specially, memcpy isn't very good at very short
280 case 4: OutBufCur[3] = Ptr[3]; // FALL THROUGH
281 case 3: OutBufCur[2] = Ptr[2]; // FALL THROUGH
282 case 2: OutBufCur[1] = Ptr[1]; // FALL THROUGH
283 case 1: OutBufCur[0] = Ptr[0]; // FALL THROUGH
286 memcpy(OutBufCur, Ptr, Size);
294 raw_ostream &raw_ostream::operator<<(const format_object_base &Fmt) {
295 // If we have more than a few bytes left in our output buffer, try
296 // formatting directly onto its end.
297 size_t NextBufferSize = 127;
298 size_t BufferBytesLeft = OutBufEnd - OutBufCur;
299 if (BufferBytesLeft > 3) {
300 size_t BytesUsed = Fmt.print(OutBufCur, BufferBytesLeft);
302 // Common case is that we have plenty of space.
303 if (BytesUsed <= BufferBytesLeft) {
304 OutBufCur += BytesUsed;
308 // Otherwise, we overflowed and the return value tells us the size to try
310 NextBufferSize = BytesUsed;
313 // If we got here, we didn't have enough space in the output buffer for the
314 // string. Try printing into a SmallVector that is resized to have enough
315 // space. Iterate until we win.
316 SmallVector<char, 128> V;
319 V.resize(NextBufferSize);
321 // Try formatting into the SmallVector.
322 size_t BytesUsed = Fmt.print(V.data(), NextBufferSize);
324 // If BytesUsed fit into the vector, we win.
325 if (BytesUsed <= NextBufferSize)
326 return write(V.data(), BytesUsed);
328 // Otherwise, try again with a new size.
329 assert(BytesUsed > NextBufferSize && "Didn't grow buffer!?");
330 NextBufferSize = BytesUsed;
334 /// indent - Insert 'NumSpaces' spaces.
335 raw_ostream &raw_ostream::indent(unsigned NumSpaces) {
336 static const char Spaces[] = " "
340 // Usually the indentation is small, handle it with a fastpath.
341 if (NumSpaces < array_lengthof(Spaces))
342 return write(Spaces, NumSpaces);
345 unsigned NumToWrite = std::min(NumSpaces,
346 (unsigned)array_lengthof(Spaces)-1);
347 write(Spaces, NumToWrite);
348 NumSpaces -= NumToWrite;
354 //===----------------------------------------------------------------------===//
356 //===----------------------------------------------------------------------===//
358 // Out of line virtual method.
359 void format_object_base::home() {
362 //===----------------------------------------------------------------------===//
364 //===----------------------------------------------------------------------===//
366 /// raw_fd_ostream - Open the specified file for writing. If an error
367 /// occurs, information about the error is put into ErrorInfo, and the
368 /// stream should be immediately destroyed; the string will be empty
369 /// if no error occurred.
370 raw_fd_ostream::raw_fd_ostream(const char *Filename, std::string &ErrorInfo,
371 unsigned Flags) : pos(0) {
372 assert(Filename != 0 && "Filename is null");
373 // Verify that we don't have both "append" and "excl".
374 assert((!(Flags & F_Excl) || !(Flags & F_Append)) &&
375 "Cannot specify both 'excl' and 'append' file creation flags!");
379 // Handle "-" as stdout.
380 if (Filename[0] == '-' && Filename[1] == 0) {
382 // If user requested binary then put stdout into binary mode if
384 if (Flags & F_Binary)
385 sys::Program::ChangeStdoutToBinary();
390 int OpenFlags = O_WRONLY|O_CREAT;
392 if (Flags & F_Binary)
393 OpenFlags |= O_BINARY;
396 if (Flags & F_Append)
397 OpenFlags |= O_APPEND;
399 OpenFlags |= O_TRUNC;
403 while ((FD = open(Filename, OpenFlags, 0664)) < 0) {
404 if (errno != EINTR) {
405 ErrorInfo = "Error opening output file '" + std::string(Filename) + "'";
411 // Ok, we successfully opened the file, so it'll need to be closed.
415 raw_fd_ostream::~raw_fd_ostream() {
419 while (::close(FD) != 0)
420 if (errno != EINTR) {
427 void raw_fd_ostream::write_impl(const char *Ptr, size_t Size) {
428 assert(FD >= 0 && "File already closed.");
433 ret = ::write(FD, Ptr, Size);
436 // If it's a recoverable error, swallow it and retry the write.
437 // EAGAIN and EWOULDBLOCK are not unambiguously recoverable, but
438 // some programs, such as bjam, assume that their child processes
439 // will treat them as if they are. If you don't want this code to
440 // spin, don't use O_NONBLOCK file descriptors with raw_ostream.
441 if (errno == EINTR || errno == EAGAIN
443 || errno == EWOULDBLOCK
448 // Otherwise it's a non-recoverable error. Note it and quit.
453 // The write may have written some or all of the data. Update the
454 // size and buffer pointer to reflect the remainder that needs
455 // to be written. If there are no bytes left, we're done.
461 void raw_fd_ostream::close() {
465 while (::close(FD) != 0)
466 if (errno != EINTR) {
473 uint64_t raw_fd_ostream::seek(uint64_t off) {
475 pos = ::lseek(FD, off, SEEK_SET);
481 size_t raw_fd_ostream::preferred_buffer_size() const {
482 #if !defined(_MSC_VER) && !defined(__MINGW32__) && !defined(_MINIX)
483 // Windows and Minix have no st_blksize.
484 assert(FD >= 0 && "File not yet open!");
486 if (fstat(FD, &statbuf) != 0)
489 // If this is a terminal, don't use buffering. Line buffering
490 // would be a more traditional thing to do, but it's not worth
492 if (S_ISCHR(statbuf.st_mode) && isatty(FD))
494 // Return the preferred block size.
495 return statbuf.st_blksize;
497 return raw_ostream::preferred_buffer_size();
500 raw_ostream &raw_fd_ostream::changeColor(enum Colors colors, bool bold,
502 if (sys::Process::ColorNeedsFlush())
504 const char *colorcode =
505 (colors == SAVEDCOLOR) ? sys::Process::OutputBold(bg)
506 : sys::Process::OutputColor(colors, bold, bg);
508 size_t len = strlen(colorcode);
509 write(colorcode, len);
510 // don't account colors towards output characters
516 raw_ostream &raw_fd_ostream::resetColor() {
517 if (sys::Process::ColorNeedsFlush())
519 const char *colorcode = sys::Process::ResetColor();
521 size_t len = strlen(colorcode);
522 write(colorcode, len);
523 // don't account colors towards output characters
529 bool raw_fd_ostream::is_displayed() const {
530 return sys::Process::FileDescriptorIsDisplayed(FD);
533 //===----------------------------------------------------------------------===//
534 // raw_stdout/err_ostream
535 //===----------------------------------------------------------------------===//
537 // Set buffer settings to model stdout and stderr behavior.
538 // Set standard error to be unbuffered by default.
539 raw_stdout_ostream::raw_stdout_ostream():raw_fd_ostream(STDOUT_FILENO, false) {}
540 raw_stderr_ostream::raw_stderr_ostream():raw_fd_ostream(STDERR_FILENO, false,
543 // An out of line virtual method to provide a home for the class vtable.
544 void raw_stdout_ostream::handle() {}
545 void raw_stderr_ostream::handle() {}
547 /// outs() - This returns a reference to a raw_ostream for standard output.
548 /// Use it like: outs() << "foo" << "bar";
549 raw_ostream &llvm::outs() {
550 static raw_stdout_ostream S;
554 /// errs() - This returns a reference to a raw_ostream for standard error.
555 /// Use it like: errs() << "foo" << "bar";
556 raw_ostream &llvm::errs() {
557 static raw_stderr_ostream S;
561 /// nulls() - This returns a reference to a raw_ostream which discards output.
562 raw_ostream &llvm::nulls() {
563 static raw_null_ostream S;
568 //===----------------------------------------------------------------------===//
569 // raw_string_ostream
570 //===----------------------------------------------------------------------===//
572 raw_string_ostream::~raw_string_ostream() {
576 void raw_string_ostream::write_impl(const char *Ptr, size_t Size) {
577 OS.append(Ptr, Size);
580 //===----------------------------------------------------------------------===//
581 // raw_svector_ostream
582 //===----------------------------------------------------------------------===//
584 // The raw_svector_ostream implementation uses the SmallVector itself as the
585 // buffer for the raw_ostream. We guarantee that the raw_ostream buffer is
586 // always pointing past the end of the vector, but within the vector
587 // capacity. This allows raw_ostream to write directly into the correct place,
588 // and we only need to set the vector size when the data is flushed.
590 raw_svector_ostream::raw_svector_ostream(SmallVectorImpl<char> &O) : OS(O) {
591 // Set up the initial external buffer. We make sure that the buffer has at
592 // least 128 bytes free; raw_ostream itself only requires 64, but we want to
593 // make sure that we don't grow the buffer unnecessarily on destruction (when
594 // the data is flushed). See the FIXME below.
595 OS.reserve(OS.size() + 128);
596 SetBuffer(OS.end(), OS.capacity() - OS.size());
599 raw_svector_ostream::~raw_svector_ostream() {
600 // FIXME: Prevent resizing during this flush().
604 /// resync - This is called when the SmallVector we're appending to is changed
605 /// outside of the raw_svector_ostream's control. It is only safe to do this
606 /// if the raw_svector_ostream has previously been flushed.
607 void raw_svector_ostream::resync() {
608 assert(GetNumBytesInBuffer() == 0 && "Didn't flush before mutating vector");
610 if (OS.capacity() - OS.size() < 64)
611 OS.reserve(OS.capacity() * 2);
612 SetBuffer(OS.end(), OS.capacity() - OS.size());
615 void raw_svector_ostream::write_impl(const char *Ptr, size_t Size) {
616 // If we're writing bytes from the end of the buffer into the smallvector, we
617 // don't need to copy the bytes, just commit the bytes because they are
618 // already in the right place.
619 if (Ptr == OS.end()) {
620 assert(OS.size() + Size <= OS.capacity() && "Invalid write_impl() call!");
621 OS.set_size(OS.size() + Size);
623 assert(GetNumBytesInBuffer() == 0 &&
624 "Should be writing from buffer if some bytes in it");
625 // Otherwise, do copy the bytes.
626 OS.append(Ptr, Ptr+Size);
629 // Grow the vector if necessary.
630 if (OS.capacity() - OS.size() < 64)
631 OS.reserve(OS.capacity() * 2);
633 // Update the buffer position.
634 SetBuffer(OS.end(), OS.capacity() - OS.size());
637 uint64_t raw_svector_ostream::current_pos() const {
641 StringRef raw_svector_ostream::str() {
643 return StringRef(OS.begin(), OS.size());
646 //===----------------------------------------------------------------------===//
648 //===----------------------------------------------------------------------===//
650 raw_null_ostream::~raw_null_ostream() {
652 // ~raw_ostream asserts that the buffer is empty. This isn't necessary
653 // with raw_null_ostream, but it's better to have raw_null_ostream follow
654 // the rules than to change the rules just for raw_null_ostream.
659 void raw_null_ostream::write_impl(const char *Ptr, size_t Size) {
662 uint64_t raw_null_ostream::current_pos() const {