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) {
148 // Avoid undefined behavior on INT64_MIN with a cast.
149 N = -(unsigned long long)N;
152 return this->operator<<(static_cast<unsigned long long>(N));
155 raw_ostream &raw_ostream::write_hex(unsigned long long N) {
156 // Zero is a special case.
160 char NumberBuffer[20];
161 char *EndPtr = NumberBuffer+sizeof(NumberBuffer);
162 char *CurPtr = EndPtr;
165 uintptr_t x = N % 16;
166 *--CurPtr = (x < 10 ? '0' + x : 'a' + x - 10);
170 return write(CurPtr, EndPtr-CurPtr);
173 raw_ostream &raw_ostream::write_escaped(StringRef Str) {
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 // Always expand to a 3-character octal escape.
198 *this << char('0' + ((c >> 6) & 7));
199 *this << char('0' + ((c >> 3) & 7));
200 *this << char('0' + ((c >> 0) & 7));
207 raw_ostream &raw_ostream::operator<<(const void *P) {
210 return write_hex((uintptr_t) P);
213 raw_ostream &raw_ostream::operator<<(double N) {
214 return this->operator<<(format("%e", N));
219 void raw_ostream::flush_nonempty() {
220 assert(OutBufCur > OutBufStart && "Invalid call to flush_nonempty.");
221 size_t Length = OutBufCur - OutBufStart;
222 OutBufCur = OutBufStart;
223 write_impl(OutBufStart, Length);
226 raw_ostream &raw_ostream::write(unsigned char C) {
227 // Group exceptional cases into a single branch.
228 if (BUILTIN_EXPECT(OutBufCur >= OutBufEnd, false)) {
229 if (BUILTIN_EXPECT(!OutBufStart, false)) {
230 if (BufferMode == Unbuffered) {
231 write_impl(reinterpret_cast<char*>(&C), 1);
234 // Set up a buffer and start over.
246 raw_ostream &raw_ostream::write(const char *Ptr, size_t Size) {
247 // Group exceptional cases into a single branch.
248 if (BUILTIN_EXPECT(OutBufCur+Size > OutBufEnd, false)) {
249 if (BUILTIN_EXPECT(!OutBufStart, false)) {
250 if (BufferMode == Unbuffered) {
251 write_impl(Ptr, Size);
254 // Set up a buffer and start over.
256 return write(Ptr, Size);
259 // Write out the data in buffer-sized blocks until the remainder
260 // fits within the buffer.
262 size_t NumBytes = OutBufEnd - OutBufCur;
263 copy_to_buffer(Ptr, NumBytes);
267 } while (OutBufCur+Size > OutBufEnd);
270 copy_to_buffer(Ptr, Size);
275 void raw_ostream::copy_to_buffer(const char *Ptr, size_t Size) {
276 assert(Size <= size_t(OutBufEnd - OutBufCur) && "Buffer overrun!");
278 // Handle short strings specially, memcpy isn't very good at very short
281 case 4: OutBufCur[3] = Ptr[3]; // FALL THROUGH
282 case 3: OutBufCur[2] = Ptr[2]; // FALL THROUGH
283 case 2: OutBufCur[1] = Ptr[1]; // FALL THROUGH
284 case 1: OutBufCur[0] = Ptr[0]; // FALL THROUGH
287 memcpy(OutBufCur, Ptr, Size);
295 raw_ostream &raw_ostream::operator<<(const format_object_base &Fmt) {
296 // If we have more than a few bytes left in our output buffer, try
297 // formatting directly onto its end.
298 size_t NextBufferSize = 127;
299 size_t BufferBytesLeft = OutBufEnd - OutBufCur;
300 if (BufferBytesLeft > 3) {
301 size_t BytesUsed = Fmt.print(OutBufCur, BufferBytesLeft);
303 // Common case is that we have plenty of space.
304 if (BytesUsed <= BufferBytesLeft) {
305 OutBufCur += BytesUsed;
309 // Otherwise, we overflowed and the return value tells us the size to try
311 NextBufferSize = BytesUsed;
314 // If we got here, we didn't have enough space in the output buffer for the
315 // string. Try printing into a SmallVector that is resized to have enough
316 // space. Iterate until we win.
317 SmallVector<char, 128> V;
320 V.resize(NextBufferSize);
322 // Try formatting into the SmallVector.
323 size_t BytesUsed = Fmt.print(V.data(), NextBufferSize);
325 // If BytesUsed fit into the vector, we win.
326 if (BytesUsed <= NextBufferSize)
327 return write(V.data(), BytesUsed);
329 // Otherwise, try again with a new size.
330 assert(BytesUsed > NextBufferSize && "Didn't grow buffer!?");
331 NextBufferSize = BytesUsed;
335 /// indent - Insert 'NumSpaces' spaces.
336 raw_ostream &raw_ostream::indent(unsigned NumSpaces) {
337 static const char Spaces[] = " "
341 // Usually the indentation is small, handle it with a fastpath.
342 if (NumSpaces < array_lengthof(Spaces))
343 return write(Spaces, NumSpaces);
346 unsigned NumToWrite = std::min(NumSpaces,
347 (unsigned)array_lengthof(Spaces)-1);
348 write(Spaces, NumToWrite);
349 NumSpaces -= NumToWrite;
355 //===----------------------------------------------------------------------===//
357 //===----------------------------------------------------------------------===//
359 // Out of line virtual method.
360 void format_object_base::home() {
363 //===----------------------------------------------------------------------===//
365 //===----------------------------------------------------------------------===//
367 /// raw_fd_ostream - Open the specified file for writing. If an error
368 /// occurs, information about the error is put into ErrorInfo, and the
369 /// stream should be immediately destroyed; the string will be empty
370 /// if no error occurred.
371 raw_fd_ostream::raw_fd_ostream(const char *Filename, std::string &ErrorInfo,
372 unsigned Flags) : pos(0) {
373 assert(Filename != 0 && "Filename is null");
374 // Verify that we don't have both "append" and "excl".
375 assert((!(Flags & F_Excl) || !(Flags & F_Append)) &&
376 "Cannot specify both 'excl' and 'append' file creation flags!");
380 // Handle "-" as stdout.
381 if (Filename[0] == '-' && Filename[1] == 0) {
383 // If user requested binary then put stdout into binary mode if
385 if (Flags & F_Binary)
386 sys::Program::ChangeStdoutToBinary();
391 int OpenFlags = O_WRONLY|O_CREAT;
393 if (Flags & F_Binary)
394 OpenFlags |= O_BINARY;
397 if (Flags & F_Append)
398 OpenFlags |= O_APPEND;
400 OpenFlags |= O_TRUNC;
404 while ((FD = open(Filename, OpenFlags, 0664)) < 0) {
405 if (errno != EINTR) {
406 ErrorInfo = "Error opening output file '" + std::string(Filename) + "'";
412 // Ok, we successfully opened the file, so it'll need to be closed.
416 raw_fd_ostream::~raw_fd_ostream() {
420 while (::close(FD) != 0)
421 if (errno != EINTR) {
428 void raw_fd_ostream::write_impl(const char *Ptr, size_t Size) {
429 assert(FD >= 0 && "File already closed.");
433 ssize_t ret = ::write(FD, Ptr, Size);
436 // If it's a recoverable error, swallow it and retry the write.
438 // Ideally we wouldn't ever see EAGAIN or EWOULDBLOCK here, since
439 // raw_ostream isn't designed to do non-blocking I/O. However, some
440 // programs, such as old versions of bjam, have mistakenly used
441 // O_NONBLOCK. For compatibility, emulate blocking semantics by
442 // spinning until the write succeeds. If you don't want spinning,
443 // don't use O_NONBLOCK file descriptors with raw_ostream.
444 if (errno == EINTR || errno == EAGAIN
446 || errno == EWOULDBLOCK
451 // Otherwise it's a non-recoverable error. Note it and quit.
456 // The write may have written some or all of the data. Update the
457 // size and buffer pointer to reflect the remainder that needs
458 // to be written. If there are no bytes left, we're done.
464 void raw_fd_ostream::close() {
468 while (::close(FD) != 0)
469 if (errno != EINTR) {
476 uint64_t raw_fd_ostream::seek(uint64_t off) {
478 pos = ::lseek(FD, off, SEEK_SET);
484 size_t raw_fd_ostream::preferred_buffer_size() const {
485 #if !defined(_MSC_VER) && !defined(__MINGW32__) && !defined(__minix)
486 // Windows and Minix have no st_blksize.
487 assert(FD >= 0 && "File not yet open!");
489 if (fstat(FD, &statbuf) != 0)
492 // If this is a terminal, don't use buffering. Line buffering
493 // would be a more traditional thing to do, but it's not worth
495 if (S_ISCHR(statbuf.st_mode) && isatty(FD))
497 // Return the preferred block size.
498 return statbuf.st_blksize;
500 return raw_ostream::preferred_buffer_size();
504 raw_ostream &raw_fd_ostream::changeColor(enum Colors colors, bool bold,
506 if (sys::Process::ColorNeedsFlush())
508 const char *colorcode =
509 (colors == SAVEDCOLOR) ? sys::Process::OutputBold(bg)
510 : sys::Process::OutputColor(colors, bold, bg);
512 size_t len = strlen(colorcode);
513 write(colorcode, len);
514 // don't account colors towards output characters
520 raw_ostream &raw_fd_ostream::resetColor() {
521 if (sys::Process::ColorNeedsFlush())
523 const char *colorcode = sys::Process::ResetColor();
525 size_t len = strlen(colorcode);
526 write(colorcode, len);
527 // don't account colors towards output characters
533 bool raw_fd_ostream::is_displayed() const {
534 return sys::Process::FileDescriptorIsDisplayed(FD);
537 //===----------------------------------------------------------------------===//
538 // raw_stdout/err_ostream
539 //===----------------------------------------------------------------------===//
541 // Set buffer settings to model stdout and stderr behavior.
542 // Set standard error to be unbuffered by default.
543 raw_stdout_ostream::raw_stdout_ostream():raw_fd_ostream(STDOUT_FILENO, false) {}
544 raw_stderr_ostream::raw_stderr_ostream():raw_fd_ostream(STDERR_FILENO, false,
547 // An out of line virtual method to provide a home for the class vtable.
548 void raw_stdout_ostream::handle() {}
549 void raw_stderr_ostream::handle() {}
551 /// outs() - This returns a reference to a raw_ostream for standard output.
552 /// Use it like: outs() << "foo" << "bar";
553 raw_ostream &llvm::outs() {
554 static raw_stdout_ostream S;
558 /// errs() - This returns a reference to a raw_ostream for standard error.
559 /// Use it like: errs() << "foo" << "bar";
560 raw_ostream &llvm::errs() {
561 static raw_stderr_ostream S;
565 /// nulls() - This returns a reference to a raw_ostream which discards output.
566 raw_ostream &llvm::nulls() {
567 static raw_null_ostream S;
572 //===----------------------------------------------------------------------===//
573 // raw_string_ostream
574 //===----------------------------------------------------------------------===//
576 raw_string_ostream::~raw_string_ostream() {
580 void raw_string_ostream::write_impl(const char *Ptr, size_t Size) {
581 OS.append(Ptr, Size);
584 //===----------------------------------------------------------------------===//
585 // raw_svector_ostream
586 //===----------------------------------------------------------------------===//
588 // The raw_svector_ostream implementation uses the SmallVector itself as the
589 // buffer for the raw_ostream. We guarantee that the raw_ostream buffer is
590 // always pointing past the end of the vector, but within the vector
591 // capacity. This allows raw_ostream to write directly into the correct place,
592 // and we only need to set the vector size when the data is flushed.
594 raw_svector_ostream::raw_svector_ostream(SmallVectorImpl<char> &O) : OS(O) {
595 // Set up the initial external buffer. We make sure that the buffer has at
596 // least 128 bytes free; raw_ostream itself only requires 64, but we want to
597 // make sure that we don't grow the buffer unnecessarily on destruction (when
598 // the data is flushed). See the FIXME below.
599 OS.reserve(OS.size() + 128);
600 SetBuffer(OS.end(), OS.capacity() - OS.size());
603 raw_svector_ostream::~raw_svector_ostream() {
604 // FIXME: Prevent resizing during this flush().
608 /// resync - This is called when the SmallVector we're appending to is changed
609 /// outside of the raw_svector_ostream's control. It is only safe to do this
610 /// if the raw_svector_ostream has previously been flushed.
611 void raw_svector_ostream::resync() {
612 assert(GetNumBytesInBuffer() == 0 && "Didn't flush before mutating vector");
614 if (OS.capacity() - OS.size() < 64)
615 OS.reserve(OS.capacity() * 2);
616 SetBuffer(OS.end(), OS.capacity() - OS.size());
619 void raw_svector_ostream::write_impl(const char *Ptr, size_t Size) {
620 // If we're writing bytes from the end of the buffer into the smallvector, we
621 // don't need to copy the bytes, just commit the bytes because they are
622 // already in the right place.
623 if (Ptr == OS.end()) {
624 assert(OS.size() + Size <= OS.capacity() && "Invalid write_impl() call!");
625 OS.set_size(OS.size() + Size);
627 assert(GetNumBytesInBuffer() == 0 &&
628 "Should be writing from buffer if some bytes in it");
629 // Otherwise, do copy the bytes.
630 OS.append(Ptr, Ptr+Size);
633 // Grow the vector if necessary.
634 if (OS.capacity() - OS.size() < 64)
635 OS.reserve(OS.capacity() * 2);
637 // Update the buffer position.
638 SetBuffer(OS.end(), OS.capacity() - OS.size());
641 uint64_t raw_svector_ostream::current_pos() const {
645 StringRef raw_svector_ostream::str() {
647 return StringRef(OS.begin(), OS.size());
650 //===----------------------------------------------------------------------===//
652 //===----------------------------------------------------------------------===//
654 raw_null_ostream::~raw_null_ostream() {
656 // ~raw_ostream asserts that the buffer is empty. This isn't necessary
657 // with raw_null_ostream, but it's better to have raw_null_ostream follow
658 // the rules than to change the rules just for raw_null_ostream.
663 void raw_null_ostream::write_impl(const char *Ptr, size_t Size) {
666 uint64_t raw_null_ostream::current_pos() const {