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;
61 // An out of line virtual method to provide a home for the class vtable.
62 void raw_ostream::handle() {}
64 size_t raw_ostream::preferred_buffer_size() const {
65 // BUFSIZ is intended to be a reasonable default.
69 void raw_ostream::SetBuffered() {
70 // Ask the subclass to determine an appropriate buffer size.
71 if (size_t Size = preferred_buffer_size())
74 // It may return 0, meaning this stream should be unbuffered.
78 void raw_ostream::SetBufferAndMode(char *BufferStart, size_t Size,
80 assert(((Mode == Unbuffered && BufferStart == 0 && Size == 0) ||
81 (Mode != Unbuffered && BufferStart && Size)) &&
82 "stream must be unbuffered or have at least one byte");
83 // Make sure the current buffer is free of content (we can't flush here; the
84 // child buffer management logic will be in write_impl).
85 assert(GetNumBytesInBuffer() == 0 && "Current buffer is non-empty!");
87 if (BufferMode == InternalBuffer)
88 delete [] OutBufStart;
89 OutBufStart = BufferStart;
90 OutBufEnd = OutBufStart+Size;
91 OutBufCur = OutBufStart;
94 assert(OutBufStart <= OutBufEnd && "Invalid size!");
97 raw_ostream &raw_ostream::operator<<(unsigned long N) {
98 // Zero is a special case.
102 char NumberBuffer[20];
103 char *EndPtr = NumberBuffer+sizeof(NumberBuffer);
104 char *CurPtr = EndPtr;
107 *--CurPtr = '0' + char(N % 10);
110 return write(CurPtr, EndPtr-CurPtr);
113 raw_ostream &raw_ostream::operator<<(long N) {
119 return this->operator<<(static_cast<unsigned long>(N));
122 raw_ostream &raw_ostream::operator<<(unsigned long long N) {
123 // Output using 32-bit div/mod when possible.
124 if (N == static_cast<unsigned long>(N))
125 return this->operator<<(static_cast<unsigned long>(N));
127 char NumberBuffer[20];
128 char *EndPtr = NumberBuffer+sizeof(NumberBuffer);
129 char *CurPtr = EndPtr;
132 *--CurPtr = '0' + char(N % 10);
135 return write(CurPtr, EndPtr-CurPtr);
138 raw_ostream &raw_ostream::operator<<(long long N) {
141 // Avoid undefined behavior on INT64_MIN with a cast.
142 N = -(unsigned long long)N;
145 return this->operator<<(static_cast<unsigned long long>(N));
148 raw_ostream &raw_ostream::write_hex(unsigned long long N) {
149 // Zero is a special case.
153 char NumberBuffer[20];
154 char *EndPtr = NumberBuffer+sizeof(NumberBuffer);
155 char *CurPtr = EndPtr;
158 uintptr_t x = N % 16;
159 *--CurPtr = (x < 10 ? '0' + x : 'a' + x - 10);
163 return write(CurPtr, EndPtr-CurPtr);
166 raw_ostream &raw_ostream::write_escaped(StringRef Str) {
167 for (unsigned i = 0, e = Str.size(); i != e; ++i) {
168 unsigned char c = Str[i];
172 *this << '\\' << '\\';
175 *this << '\\' << 't';
178 *this << '\\' << 'n';
181 *this << '\\' << '"';
184 if (std::isprint(c)) {
189 // Always expand to a 3-character octal escape.
191 *this << char('0' + ((c >> 6) & 7));
192 *this << char('0' + ((c >> 3) & 7));
193 *this << char('0' + ((c >> 0) & 7));
200 raw_ostream &raw_ostream::operator<<(const void *P) {
203 return write_hex((uintptr_t) P);
206 raw_ostream &raw_ostream::operator<<(double N) {
207 return this->operator<<(format("%e", N));
212 void raw_ostream::flush_nonempty() {
213 assert(OutBufCur > OutBufStart && "Invalid call to flush_nonempty.");
214 size_t Length = OutBufCur - OutBufStart;
215 OutBufCur = OutBufStart;
216 write_impl(OutBufStart, Length);
219 raw_ostream &raw_ostream::write(unsigned char C) {
220 // Group exceptional cases into a single branch.
221 if (BUILTIN_EXPECT(OutBufCur >= OutBufEnd, false)) {
222 if (BUILTIN_EXPECT(!OutBufStart, false)) {
223 if (BufferMode == Unbuffered) {
224 write_impl(reinterpret_cast<char*>(&C), 1);
227 // Set up a buffer and start over.
239 raw_ostream &raw_ostream::write(const char *Ptr, size_t Size) {
240 // Group exceptional cases into a single branch.
241 if (BUILTIN_EXPECT(OutBufCur+Size > OutBufEnd, false)) {
242 if (BUILTIN_EXPECT(!OutBufStart, false)) {
243 if (BufferMode == Unbuffered) {
244 write_impl(Ptr, Size);
247 // Set up a buffer and start over.
249 return write(Ptr, Size);
252 // Write out the data in buffer-sized blocks until the remainder
253 // fits within the buffer.
255 size_t NumBytes = OutBufEnd - OutBufCur;
256 copy_to_buffer(Ptr, NumBytes);
260 } while (OutBufCur+Size > OutBufEnd);
263 copy_to_buffer(Ptr, Size);
268 void raw_ostream::copy_to_buffer(const char *Ptr, size_t Size) {
269 assert(Size <= size_t(OutBufEnd - OutBufCur) && "Buffer overrun!");
271 // Handle short strings specially, memcpy isn't very good at very short
274 case 4: OutBufCur[3] = Ptr[3]; // FALL THROUGH
275 case 3: OutBufCur[2] = Ptr[2]; // FALL THROUGH
276 case 2: OutBufCur[1] = Ptr[1]; // FALL THROUGH
277 case 1: OutBufCur[0] = Ptr[0]; // FALL THROUGH
280 memcpy(OutBufCur, Ptr, Size);
288 raw_ostream &raw_ostream::operator<<(const format_object_base &Fmt) {
289 // If we have more than a few bytes left in our output buffer, try
290 // formatting directly onto its end.
291 size_t NextBufferSize = 127;
292 size_t BufferBytesLeft = OutBufEnd - OutBufCur;
293 if (BufferBytesLeft > 3) {
294 size_t BytesUsed = Fmt.print(OutBufCur, BufferBytesLeft);
296 // Common case is that we have plenty of space.
297 if (BytesUsed <= BufferBytesLeft) {
298 OutBufCur += BytesUsed;
302 // Otherwise, we overflowed and the return value tells us the size to try
304 NextBufferSize = BytesUsed;
307 // If we got here, we didn't have enough space in the output buffer for the
308 // string. Try printing into a SmallVector that is resized to have enough
309 // space. Iterate until we win.
310 SmallVector<char, 128> V;
313 V.resize(NextBufferSize);
315 // Try formatting into the SmallVector.
316 size_t BytesUsed = Fmt.print(V.data(), NextBufferSize);
318 // If BytesUsed fit into the vector, we win.
319 if (BytesUsed <= NextBufferSize)
320 return write(V.data(), BytesUsed);
322 // Otherwise, try again with a new size.
323 assert(BytesUsed > NextBufferSize && "Didn't grow buffer!?");
324 NextBufferSize = BytesUsed;
328 /// indent - Insert 'NumSpaces' spaces.
329 raw_ostream &raw_ostream::indent(unsigned NumSpaces) {
330 static const char Spaces[] = " "
334 // Usually the indentation is small, handle it with a fastpath.
335 if (NumSpaces < array_lengthof(Spaces))
336 return write(Spaces, NumSpaces);
339 unsigned NumToWrite = std::min(NumSpaces,
340 (unsigned)array_lengthof(Spaces)-1);
341 write(Spaces, NumToWrite);
342 NumSpaces -= NumToWrite;
348 //===----------------------------------------------------------------------===//
350 //===----------------------------------------------------------------------===//
352 // Out of line virtual method.
353 void format_object_base::home() {
356 //===----------------------------------------------------------------------===//
358 //===----------------------------------------------------------------------===//
360 /// raw_fd_ostream - Open the specified file for writing. If an error
361 /// occurs, information about the error is put into ErrorInfo, and the
362 /// stream should be immediately destroyed; the string will be empty
363 /// if no error occurred.
364 raw_fd_ostream::raw_fd_ostream(const char *Filename, std::string &ErrorInfo,
365 unsigned Flags) : Error(false), pos(0) {
366 assert(Filename != 0 && "Filename is null");
367 // Verify that we don't have both "append" and "excl".
368 assert((!(Flags & F_Excl) || !(Flags & F_Append)) &&
369 "Cannot specify both 'excl' and 'append' file creation flags!");
373 // Handle "-" as stdout. Note that when we do this, we consider ourself
374 // the owner of stdout. This means that we can do things like close the
375 // file descriptor when we're done and set the "binary" flag globally.
376 if (Filename[0] == '-' && Filename[1] == 0) {
378 // If user requested binary then put stdout into binary mode if
380 if (Flags & F_Binary)
381 sys::Program::ChangeStdoutToBinary();
382 // Close stdout when we're done, to detect any output errors.
387 int OpenFlags = O_WRONLY|O_CREAT;
389 if (Flags & F_Binary)
390 OpenFlags |= O_BINARY;
393 if (Flags & F_Append)
394 OpenFlags |= O_APPEND;
396 OpenFlags |= O_TRUNC;
400 while ((FD = open(Filename, OpenFlags, 0664)) < 0) {
401 if (errno != EINTR) {
402 ErrorInfo = "Error opening output file '" + std::string(Filename) + "'";
408 // Ok, we successfully opened the file, so it'll need to be closed.
412 raw_fd_ostream::~raw_fd_ostream() {
416 while (::close(FD) != 0)
417 if (errno != EINTR) {
423 // If there are any pending errors, report them now. Clients wishing
424 // to avoid report_fatal_error calls should check for errors with
425 // has_error() and clear the error flag with clear_error() before
426 // destructing raw_ostream objects which may have errors.
428 report_fatal_error("IO failure on output stream.");
432 void raw_fd_ostream::write_impl(const char *Ptr, size_t Size) {
433 assert(FD >= 0 && "File already closed.");
437 ssize_t ret = ::write(FD, Ptr, Size);
440 // If it's a recoverable error, swallow it and retry the write.
442 // Ideally we wouldn't ever see EAGAIN or EWOULDBLOCK here, since
443 // raw_ostream isn't designed to do non-blocking I/O. However, some
444 // programs, such as old versions of bjam, have mistakenly used
445 // O_NONBLOCK. For compatibility, emulate blocking semantics by
446 // spinning until the write succeeds. If you don't want spinning,
447 // don't use O_NONBLOCK file descriptors with raw_ostream.
448 if (errno == EINTR || errno == EAGAIN
450 || errno == EWOULDBLOCK
455 // Otherwise it's a non-recoverable error. Note it and quit.
460 // The write may have written some or all of the data. Update the
461 // size and buffer pointer to reflect the remainder that needs
462 // to be written. If there are no bytes left, we're done.
468 void raw_fd_ostream::close() {
472 while (::close(FD) != 0)
473 if (errno != EINTR) {
480 uint64_t raw_fd_ostream::seek(uint64_t off) {
482 pos = ::lseek(FD, off, SEEK_SET);
488 size_t raw_fd_ostream::preferred_buffer_size() const {
489 #if !defined(_MSC_VER) && !defined(__MINGW32__) && !defined(__minix)
490 // Windows and Minix have no st_blksize.
491 assert(FD >= 0 && "File not yet open!");
493 if (fstat(FD, &statbuf) != 0)
496 // If this is a terminal, don't use buffering. Line buffering
497 // would be a more traditional thing to do, but it's not worth
499 if (S_ISCHR(statbuf.st_mode) && isatty(FD))
501 // Return the preferred block size.
502 return statbuf.st_blksize;
504 return raw_ostream::preferred_buffer_size();
508 raw_ostream &raw_fd_ostream::changeColor(enum Colors colors, bool bold,
510 if (sys::Process::ColorNeedsFlush())
512 const char *colorcode =
513 (colors == SAVEDCOLOR) ? sys::Process::OutputBold(bg)
514 : sys::Process::OutputColor(colors, bold, bg);
516 size_t len = strlen(colorcode);
517 write(colorcode, len);
518 // don't account colors towards output characters
524 raw_ostream &raw_fd_ostream::resetColor() {
525 if (sys::Process::ColorNeedsFlush())
527 const char *colorcode = sys::Process::ResetColor();
529 size_t len = strlen(colorcode);
530 write(colorcode, len);
531 // don't account colors towards output characters
537 bool raw_fd_ostream::is_displayed() const {
538 return sys::Process::FileDescriptorIsDisplayed(FD);
541 //===----------------------------------------------------------------------===//
542 // outs(), errs(), nulls()
543 //===----------------------------------------------------------------------===//
545 /// outs() - This returns a reference to a raw_ostream for standard output.
546 /// Use it like: outs() << "foo" << "bar";
547 raw_ostream &llvm::outs() {
548 // Set buffer settings to model stdout behavior.
549 // Delete the file descriptor when the program exists, forcing error
550 // detection. If you don't want this behavior, don't use outs().
551 static raw_fd_ostream S(STDOUT_FILENO, true);
555 /// errs() - This returns a reference to a raw_ostream for standard error.
556 /// Use it like: errs() << "foo" << "bar";
557 raw_ostream &llvm::errs() {
558 // Set standard error to be unbuffered by default.
559 static raw_fd_ostream S(STDERR_FILENO, false, true);
563 /// nulls() - This returns a reference to a raw_ostream which discards output.
564 raw_ostream &llvm::nulls() {
565 static raw_null_ostream S;
570 //===----------------------------------------------------------------------===//
571 // raw_string_ostream
572 //===----------------------------------------------------------------------===//
574 raw_string_ostream::~raw_string_ostream() {
578 void raw_string_ostream::write_impl(const char *Ptr, size_t Size) {
579 OS.append(Ptr, Size);
582 //===----------------------------------------------------------------------===//
583 // raw_svector_ostream
584 //===----------------------------------------------------------------------===//
586 // The raw_svector_ostream implementation uses the SmallVector itself as the
587 // buffer for the raw_ostream. We guarantee that the raw_ostream buffer is
588 // always pointing past the end of the vector, but within the vector
589 // capacity. This allows raw_ostream to write directly into the correct place,
590 // and we only need to set the vector size when the data is flushed.
592 raw_svector_ostream::raw_svector_ostream(SmallVectorImpl<char> &O) : OS(O) {
593 // Set up the initial external buffer. We make sure that the buffer has at
594 // least 128 bytes free; raw_ostream itself only requires 64, but we want to
595 // make sure that we don't grow the buffer unnecessarily on destruction (when
596 // the data is flushed). See the FIXME below.
597 OS.reserve(OS.size() + 128);
598 SetBuffer(OS.end(), OS.capacity() - OS.size());
601 raw_svector_ostream::~raw_svector_ostream() {
602 // FIXME: Prevent resizing during this flush().
606 /// resync - This is called when the SmallVector we're appending to is changed
607 /// outside of the raw_svector_ostream's control. It is only safe to do this
608 /// if the raw_svector_ostream has previously been flushed.
609 void raw_svector_ostream::resync() {
610 assert(GetNumBytesInBuffer() == 0 && "Didn't flush before mutating vector");
612 if (OS.capacity() - OS.size() < 64)
613 OS.reserve(OS.capacity() * 2);
614 SetBuffer(OS.end(), OS.capacity() - OS.size());
617 void raw_svector_ostream::write_impl(const char *Ptr, size_t Size) {
618 // If we're writing bytes from the end of the buffer into the smallvector, we
619 // don't need to copy the bytes, just commit the bytes because they are
620 // already in the right place.
621 if (Ptr == OS.end()) {
622 assert(OS.size() + Size <= OS.capacity() && "Invalid write_impl() call!");
623 OS.set_size(OS.size() + Size);
625 assert(GetNumBytesInBuffer() == 0 &&
626 "Should be writing from buffer if some bytes in it");
627 // Otherwise, do copy the bytes.
628 OS.append(Ptr, Ptr+Size);
631 // Grow the vector if necessary.
632 if (OS.capacity() - OS.size() < 64)
633 OS.reserve(OS.capacity() * 2);
635 // Update the buffer position.
636 SetBuffer(OS.end(), OS.capacity() - OS.size());
639 uint64_t raw_svector_ostream::current_pos() const {
643 StringRef raw_svector_ostream::str() {
645 return StringRef(OS.begin(), OS.size());
648 //===----------------------------------------------------------------------===//
650 //===----------------------------------------------------------------------===//
652 raw_null_ostream::~raw_null_ostream() {
654 // ~raw_ostream asserts that the buffer is empty. This isn't necessary
655 // with raw_null_ostream, but it's better to have raw_null_ostream follow
656 // the rules than to change the rules just for raw_null_ostream.
661 void raw_null_ostream::write_impl(const char *Ptr, size_t Size) {
664 uint64_t raw_null_ostream::current_pos() const {