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)
36 #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) {
124 return this->operator<<(static_cast<unsigned long>(N));
127 raw_ostream &raw_ostream::operator<<(unsigned long long N) {
128 // Output using 32-bit div/mod when possible.
129 if (N == static_cast<unsigned long>(N))
130 return this->operator<<(static_cast<unsigned long>(N));
132 char NumberBuffer[20];
133 char *EndPtr = NumberBuffer+sizeof(NumberBuffer);
134 char *CurPtr = EndPtr;
137 *--CurPtr = '0' + char(N % 10);
140 return write(CurPtr, EndPtr-CurPtr);
143 raw_ostream &raw_ostream::operator<<(long long N) {
146 // Avoid undefined behavior on INT64_MIN with a cast.
147 N = -(unsigned long long)N;
150 return this->operator<<(static_cast<unsigned long long>(N));
153 raw_ostream &raw_ostream::write_hex(unsigned long long N) {
154 // Zero is a special case.
158 char NumberBuffer[20];
159 char *EndPtr = NumberBuffer+sizeof(NumberBuffer);
160 char *CurPtr = EndPtr;
163 uintptr_t x = N % 16;
164 *--CurPtr = (x < 10 ? '0' + x : 'a' + x - 10);
168 return write(CurPtr, EndPtr-CurPtr);
171 raw_ostream &raw_ostream::write_escaped(StringRef Str,
172 bool UseHexEscapes) {
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 // Write out the escaped representation.
197 *this << '\\' << 'x';
198 *this << hexdigit((c >> 4 & 0xF));
199 *this << hexdigit((c >> 0) & 0xF);
201 // Always use a full 3-character octal escape.
203 *this << char('0' + ((c >> 6) & 7));
204 *this << char('0' + ((c >> 3) & 7));
205 *this << char('0' + ((c >> 0) & 7));
213 raw_ostream &raw_ostream::operator<<(const void *P) {
216 return write_hex((uintptr_t) P);
219 raw_ostream &raw_ostream::operator<<(double N) {
220 return this->operator<<(format("%e", N));
225 void raw_ostream::flush_nonempty() {
226 assert(OutBufCur > OutBufStart && "Invalid call to flush_nonempty.");
227 size_t Length = OutBufCur - OutBufStart;
228 OutBufCur = OutBufStart;
229 write_impl(OutBufStart, Length);
232 raw_ostream &raw_ostream::write(unsigned char C) {
233 // Group exceptional cases into a single branch.
234 if (BUILTIN_EXPECT(OutBufCur >= OutBufEnd, false)) {
235 if (BUILTIN_EXPECT(!OutBufStart, false)) {
236 if (BufferMode == Unbuffered) {
237 write_impl(reinterpret_cast<char*>(&C), 1);
240 // Set up a buffer and start over.
252 raw_ostream &raw_ostream::write(const char *Ptr, size_t Size) {
253 // Group exceptional cases into a single branch.
254 if (BUILTIN_EXPECT(OutBufCur+Size > OutBufEnd, false)) {
255 if (BUILTIN_EXPECT(!OutBufStart, false)) {
256 if (BufferMode == Unbuffered) {
257 write_impl(Ptr, Size);
260 // Set up a buffer and start over.
262 return write(Ptr, Size);
265 // Write out the data in buffer-sized blocks until the remainder
266 // fits within the buffer.
268 size_t NumBytes = OutBufEnd - OutBufCur;
269 copy_to_buffer(Ptr, NumBytes);
273 } while (OutBufCur+Size > OutBufEnd);
276 copy_to_buffer(Ptr, Size);
281 void raw_ostream::copy_to_buffer(const char *Ptr, size_t Size) {
282 assert(Size <= size_t(OutBufEnd - OutBufCur) && "Buffer overrun!");
284 // Handle short strings specially, memcpy isn't very good at very short
287 case 4: OutBufCur[3] = Ptr[3]; // FALL THROUGH
288 case 3: OutBufCur[2] = Ptr[2]; // FALL THROUGH
289 case 2: OutBufCur[1] = Ptr[1]; // FALL THROUGH
290 case 1: OutBufCur[0] = Ptr[0]; // FALL THROUGH
293 memcpy(OutBufCur, Ptr, Size);
301 raw_ostream &raw_ostream::operator<<(const format_object_base &Fmt) {
302 // If we have more than a few bytes left in our output buffer, try
303 // formatting directly onto its end.
304 size_t NextBufferSize = 127;
305 size_t BufferBytesLeft = OutBufEnd - OutBufCur;
306 if (BufferBytesLeft > 3) {
307 size_t BytesUsed = Fmt.print(OutBufCur, BufferBytesLeft);
309 // Common case is that we have plenty of space.
310 if (BytesUsed <= BufferBytesLeft) {
311 OutBufCur += BytesUsed;
315 // Otherwise, we overflowed and the return value tells us the size to try
317 NextBufferSize = BytesUsed;
320 // If we got here, we didn't have enough space in the output buffer for the
321 // string. Try printing into a SmallVector that is resized to have enough
322 // space. Iterate until we win.
323 SmallVector<char, 128> V;
326 V.resize(NextBufferSize);
328 // Try formatting into the SmallVector.
329 size_t BytesUsed = Fmt.print(V.data(), NextBufferSize);
331 // If BytesUsed fit into the vector, we win.
332 if (BytesUsed <= NextBufferSize)
333 return write(V.data(), BytesUsed);
335 // Otherwise, try again with a new size.
336 assert(BytesUsed > NextBufferSize && "Didn't grow buffer!?");
337 NextBufferSize = BytesUsed;
341 /// indent - Insert 'NumSpaces' spaces.
342 raw_ostream &raw_ostream::indent(unsigned NumSpaces) {
343 static const char Spaces[] = " "
347 // Usually the indentation is small, handle it with a fastpath.
348 if (NumSpaces < array_lengthof(Spaces))
349 return write(Spaces, NumSpaces);
352 unsigned NumToWrite = std::min(NumSpaces,
353 (unsigned)array_lengthof(Spaces)-1);
354 write(Spaces, NumToWrite);
355 NumSpaces -= NumToWrite;
361 //===----------------------------------------------------------------------===//
363 //===----------------------------------------------------------------------===//
365 // Out of line virtual method.
366 void format_object_base::home() {
369 //===----------------------------------------------------------------------===//
371 //===----------------------------------------------------------------------===//
373 /// raw_fd_ostream - Open the specified file for writing. If an error
374 /// occurs, information about the error is put into ErrorInfo, and the
375 /// stream should be immediately destroyed; the string will be empty
376 /// if no error occurred.
377 raw_fd_ostream::raw_fd_ostream(const char *Filename, std::string &ErrorInfo,
378 unsigned Flags) : Error(false), pos(0) {
379 assert(Filename != 0 && "Filename is null");
380 // Verify that we don't have both "append" and "excl".
381 assert((!(Flags & F_Excl) || !(Flags & F_Append)) &&
382 "Cannot specify both 'excl' and 'append' file creation flags!");
386 // Handle "-" as stdout. Note that when we do this, we consider ourself
387 // the owner of stdout. This means that we can do things like close the
388 // file descriptor when we're done and set the "binary" flag globally.
389 if (Filename[0] == '-' && Filename[1] == 0) {
391 // If user requested binary then put stdout into binary mode if
393 if (Flags & F_Binary)
394 sys::Program::ChangeStdoutToBinary();
395 // Close stdout when we're done, to detect any output errors.
400 int OpenFlags = O_WRONLY|O_CREAT;
402 if (Flags & F_Binary)
403 OpenFlags |= O_BINARY;
406 if (Flags & F_Append)
407 OpenFlags |= O_APPEND;
409 OpenFlags |= O_TRUNC;
413 while ((FD = open(Filename, OpenFlags, 0664)) < 0) {
414 if (errno != EINTR) {
415 ErrorInfo = "Error opening output file '" + std::string(Filename) + "'";
421 // Ok, we successfully opened the file, so it'll need to be closed.
425 /// raw_fd_ostream ctor - FD is the file descriptor that this writes to. If
426 /// ShouldClose is true, this closes the file when the stream is destroyed.
427 raw_fd_ostream::raw_fd_ostream(int fd, bool shouldClose, bool unbuffered)
428 : raw_ostream(unbuffered), FD(fd),
429 ShouldClose(shouldClose), Error(false) {
431 // Setting STDOUT and STDERR to binary mode is necessary in Win32
432 // to avoid undesirable linefeed conversion.
433 if (fd == STDOUT_FILENO || fd == STDERR_FILENO)
434 setmode(fd, O_BINARY);
438 raw_fd_ostream::~raw_fd_ostream() {
442 while (::close(FD) != 0)
443 if (errno != EINTR) {
449 // If there are any pending errors, report them now. Clients wishing
450 // to avoid report_fatal_error calls should check for errors with
451 // has_error() and clear the error flag with clear_error() before
452 // destructing raw_ostream objects which may have errors.
454 report_fatal_error("IO failure on output stream.");
458 void raw_fd_ostream::write_impl(const char *Ptr, size_t Size) {
459 assert(FD >= 0 && "File already closed.");
463 ssize_t ret = ::write(FD, Ptr, Size);
466 // If it's a recoverable error, swallow it and retry the write.
468 // Ideally we wouldn't ever see EAGAIN or EWOULDBLOCK here, since
469 // raw_ostream isn't designed to do non-blocking I/O. However, some
470 // programs, such as old versions of bjam, have mistakenly used
471 // O_NONBLOCK. For compatibility, emulate blocking semantics by
472 // spinning until the write succeeds. If you don't want spinning,
473 // don't use O_NONBLOCK file descriptors with raw_ostream.
474 if (errno == EINTR || errno == EAGAIN
476 || errno == EWOULDBLOCK
481 // Otherwise it's a non-recoverable error. Note it and quit.
486 // The write may have written some or all of the data. Update the
487 // size and buffer pointer to reflect the remainder that needs
488 // to be written. If there are no bytes left, we're done.
494 void raw_fd_ostream::close() {
498 while (::close(FD) != 0)
499 if (errno != EINTR) {
506 uint64_t raw_fd_ostream::seek(uint64_t off) {
508 pos = ::lseek(FD, off, SEEK_SET);
514 size_t raw_fd_ostream::preferred_buffer_size() const {
515 #if !defined(_MSC_VER) && !defined(__MINGW32__) && !defined(__minix)
516 // Windows and Minix have no st_blksize.
517 assert(FD >= 0 && "File not yet open!");
519 if (fstat(FD, &statbuf) != 0)
522 // If this is a terminal, don't use buffering. Line buffering
523 // would be a more traditional thing to do, but it's not worth
525 if (S_ISCHR(statbuf.st_mode) && isatty(FD))
527 // Return the preferred block size.
528 return statbuf.st_blksize;
530 return raw_ostream::preferred_buffer_size();
534 raw_ostream &raw_fd_ostream::changeColor(enum Colors colors, bool bold,
536 if (sys::Process::ColorNeedsFlush())
538 const char *colorcode =
539 (colors == SAVEDCOLOR) ? sys::Process::OutputBold(bg)
540 : sys::Process::OutputColor(colors, bold, bg);
542 size_t len = strlen(colorcode);
543 write(colorcode, len);
544 // don't account colors towards output characters
550 raw_ostream &raw_fd_ostream::resetColor() {
551 if (sys::Process::ColorNeedsFlush())
553 const char *colorcode = sys::Process::ResetColor();
555 size_t len = strlen(colorcode);
556 write(colorcode, len);
557 // don't account colors towards output characters
563 bool raw_fd_ostream::is_displayed() const {
564 return sys::Process::FileDescriptorIsDisplayed(FD);
567 //===----------------------------------------------------------------------===//
568 // outs(), errs(), nulls()
569 //===----------------------------------------------------------------------===//
571 /// outs() - This returns a reference to a raw_ostream for standard output.
572 /// Use it like: outs() << "foo" << "bar";
573 raw_ostream &llvm::outs() {
574 // Set buffer settings to model stdout behavior.
575 // Delete the file descriptor when the program exists, forcing error
576 // detection. If you don't want this behavior, don't use outs().
577 static raw_fd_ostream S(STDOUT_FILENO, true);
581 /// errs() - This returns a reference to a raw_ostream for standard error.
582 /// Use it like: errs() << "foo" << "bar";
583 raw_ostream &llvm::errs() {
584 // Set standard error to be unbuffered by default.
585 static raw_fd_ostream S(STDERR_FILENO, false, true);
589 /// nulls() - This returns a reference to a raw_ostream which discards output.
590 raw_ostream &llvm::nulls() {
591 static raw_null_ostream S;
596 //===----------------------------------------------------------------------===//
597 // raw_string_ostream
598 //===----------------------------------------------------------------------===//
600 raw_string_ostream::~raw_string_ostream() {
604 void raw_string_ostream::write_impl(const char *Ptr, size_t Size) {
605 OS.append(Ptr, Size);
608 //===----------------------------------------------------------------------===//
609 // raw_svector_ostream
610 //===----------------------------------------------------------------------===//
612 // The raw_svector_ostream implementation uses the SmallVector itself as the
613 // buffer for the raw_ostream. We guarantee that the raw_ostream buffer is
614 // always pointing past the end of the vector, but within the vector
615 // capacity. This allows raw_ostream to write directly into the correct place,
616 // and we only need to set the vector size when the data is flushed.
618 raw_svector_ostream::raw_svector_ostream(SmallVectorImpl<char> &O) : OS(O) {
619 // Set up the initial external buffer. We make sure that the buffer has at
620 // least 128 bytes free; raw_ostream itself only requires 64, but we want to
621 // make sure that we don't grow the buffer unnecessarily on destruction (when
622 // the data is flushed). See the FIXME below.
623 OS.reserve(OS.size() + 128);
624 SetBuffer(OS.end(), OS.capacity() - OS.size());
627 raw_svector_ostream::~raw_svector_ostream() {
628 // FIXME: Prevent resizing during this flush().
632 /// resync - This is called when the SmallVector we're appending to is changed
633 /// outside of the raw_svector_ostream's control. It is only safe to do this
634 /// if the raw_svector_ostream has previously been flushed.
635 void raw_svector_ostream::resync() {
636 assert(GetNumBytesInBuffer() == 0 && "Didn't flush before mutating vector");
638 if (OS.capacity() - OS.size() < 64)
639 OS.reserve(OS.capacity() * 2);
640 SetBuffer(OS.end(), OS.capacity() - OS.size());
643 void raw_svector_ostream::write_impl(const char *Ptr, size_t Size) {
644 // If we're writing bytes from the end of the buffer into the smallvector, we
645 // don't need to copy the bytes, just commit the bytes because they are
646 // already in the right place.
647 if (Ptr == OS.end()) {
648 assert(OS.size() + Size <= OS.capacity() && "Invalid write_impl() call!");
649 OS.set_size(OS.size() + Size);
651 assert(GetNumBytesInBuffer() == 0 &&
652 "Should be writing from buffer if some bytes in it");
653 // Otherwise, do copy the bytes.
654 OS.append(Ptr, Ptr+Size);
657 // Grow the vector if necessary.
658 if (OS.capacity() - OS.size() < 64)
659 OS.reserve(OS.capacity() * 2);
661 // Update the buffer position.
662 SetBuffer(OS.end(), OS.capacity() - OS.size());
665 uint64_t raw_svector_ostream::current_pos() const {
669 StringRef raw_svector_ostream::str() {
671 return StringRef(OS.begin(), OS.size());
674 //===----------------------------------------------------------------------===//
676 //===----------------------------------------------------------------------===//
678 raw_null_ostream::~raw_null_ostream() {
680 // ~raw_ostream asserts that the buffer is empty. This isn't necessary
681 // with raw_null_ostream, but it's better to have raw_null_ostream follow
682 // the rules than to change the rules just for raw_null_ostream.
687 void raw_null_ostream::write_impl(const char *Ptr, size_t Size) {
690 uint64_t raw_null_ostream::current_pos() const {