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/System/Signals.h"
23 #include "llvm/ADT/STLExtras.h"
27 #include <sys/types.h>
29 #if defined(HAVE_UNISTD_H)
32 #if defined(HAVE_FCNTL_H)
40 # define STDIN_FILENO 0
43 # define STDOUT_FILENO 1
46 # define STDERR_FILENO 2
52 raw_ostream::~raw_ostream() {
53 // raw_ostream's subclasses should take care to flush the buffer
54 // in their destructors.
55 assert(OutBufCur == OutBufStart &&
56 "raw_ostream destructor called with non-empty buffer!");
58 if (BufferMode == InternalBuffer)
59 delete [] OutBufStart;
62 // An out of line virtual method to provide a home for the class vtable.
63 void raw_ostream::handle() {}
65 size_t raw_ostream::preferred_buffer_size() const {
66 // BUFSIZ is intended to be a reasonable default.
70 void raw_ostream::SetBuffered() {
71 // Ask the subclass to determine an appropriate buffer size.
72 if (size_t Size = preferred_buffer_size())
75 // It may return 0, meaning this stream should be unbuffered.
79 void raw_ostream::SetBufferAndMode(char *BufferStart, size_t Size,
81 assert(((Mode == Unbuffered && BufferStart == 0 && Size == 0) ||
82 (Mode != Unbuffered && BufferStart && Size)) &&
83 "stream must be unbuffered or have at least one byte");
84 // Make sure the current buffer is free of content (we can't flush here; the
85 // child buffer management logic will be in write_impl).
86 assert(GetNumBytesInBuffer() == 0 && "Current buffer is non-empty!");
88 if (BufferMode == InternalBuffer)
89 delete [] OutBufStart;
90 OutBufStart = BufferStart;
91 OutBufEnd = OutBufStart+Size;
92 OutBufCur = OutBufStart;
95 assert(OutBufStart <= OutBufEnd && "Invalid size!");
98 raw_ostream &raw_ostream::operator<<(unsigned long N) {
99 // Zero is a special case.
103 char NumberBuffer[20];
104 char *EndPtr = NumberBuffer+sizeof(NumberBuffer);
105 char *CurPtr = EndPtr;
108 *--CurPtr = '0' + char(N % 10);
111 return write(CurPtr, EndPtr-CurPtr);
114 raw_ostream &raw_ostream::operator<<(long N) {
120 return this->operator<<(static_cast<unsigned long>(N));
123 raw_ostream &raw_ostream::operator<<(unsigned long long N) {
124 // Output using 32-bit div/mod when possible.
125 if (N == static_cast<unsigned long>(N))
126 return this->operator<<(static_cast<unsigned long>(N));
128 char NumberBuffer[20];
129 char *EndPtr = NumberBuffer+sizeof(NumberBuffer);
130 char *CurPtr = EndPtr;
133 *--CurPtr = '0' + char(N % 10);
136 return write(CurPtr, EndPtr-CurPtr);
139 raw_ostream &raw_ostream::operator<<(long long N) {
142 // Avoid undefined behavior on INT64_MIN with a cast.
143 N = -(unsigned long long)N;
146 return this->operator<<(static_cast<unsigned long long>(N));
149 raw_ostream &raw_ostream::write_hex(unsigned long long N) {
150 // Zero is a special case.
154 char NumberBuffer[20];
155 char *EndPtr = NumberBuffer+sizeof(NumberBuffer);
156 char *CurPtr = EndPtr;
159 uintptr_t x = N % 16;
160 *--CurPtr = (x < 10 ? '0' + x : 'a' + x - 10);
164 return write(CurPtr, EndPtr-CurPtr);
167 raw_ostream &raw_ostream::write_escaped(StringRef Str) {
168 for (unsigned i = 0, e = Str.size(); i != e; ++i) {
169 unsigned char c = Str[i];
173 *this << '\\' << '\\';
176 *this << '\\' << 't';
179 *this << '\\' << 'n';
182 *this << '\\' << '"';
185 if (std::isprint(c)) {
190 // Always expand to a 3-character octal escape.
192 *this << char('0' + ((c >> 6) & 7));
193 *this << char('0' + ((c >> 3) & 7));
194 *this << char('0' + ((c >> 0) & 7));
201 raw_ostream &raw_ostream::operator<<(const void *P) {
204 return write_hex((uintptr_t) P);
207 raw_ostream &raw_ostream::operator<<(double N) {
208 return this->operator<<(format("%e", N));
213 void raw_ostream::flush_nonempty() {
214 assert(OutBufCur > OutBufStart && "Invalid call to flush_nonempty.");
215 size_t Length = OutBufCur - OutBufStart;
216 OutBufCur = OutBufStart;
217 write_impl(OutBufStart, Length);
220 raw_ostream &raw_ostream::write(unsigned char C) {
221 // Group exceptional cases into a single branch.
222 if (BUILTIN_EXPECT(OutBufCur >= OutBufEnd, false)) {
223 if (BUILTIN_EXPECT(!OutBufStart, false)) {
224 if (BufferMode == Unbuffered) {
225 write_impl(reinterpret_cast<char*>(&C), 1);
228 // Set up a buffer and start over.
240 raw_ostream &raw_ostream::write(const char *Ptr, size_t Size) {
241 // Group exceptional cases into a single branch.
242 if (BUILTIN_EXPECT(OutBufCur+Size > OutBufEnd, false)) {
243 if (BUILTIN_EXPECT(!OutBufStart, false)) {
244 if (BufferMode == Unbuffered) {
245 write_impl(Ptr, Size);
248 // Set up a buffer and start over.
250 return write(Ptr, Size);
253 // Write out the data in buffer-sized blocks until the remainder
254 // fits within the buffer.
256 size_t NumBytes = OutBufEnd - OutBufCur;
257 copy_to_buffer(Ptr, NumBytes);
261 } while (OutBufCur+Size > OutBufEnd);
264 copy_to_buffer(Ptr, Size);
269 void raw_ostream::copy_to_buffer(const char *Ptr, size_t Size) {
270 assert(Size <= size_t(OutBufEnd - OutBufCur) && "Buffer overrun!");
272 // Handle short strings specially, memcpy isn't very good at very short
275 case 4: OutBufCur[3] = Ptr[3]; // FALL THROUGH
276 case 3: OutBufCur[2] = Ptr[2]; // FALL THROUGH
277 case 2: OutBufCur[1] = Ptr[1]; // FALL THROUGH
278 case 1: OutBufCur[0] = Ptr[0]; // FALL THROUGH
281 memcpy(OutBufCur, Ptr, Size);
289 raw_ostream &raw_ostream::operator<<(const format_object_base &Fmt) {
290 // If we have more than a few bytes left in our output buffer, try
291 // formatting directly onto its end.
292 size_t NextBufferSize = 127;
293 size_t BufferBytesLeft = OutBufEnd - OutBufCur;
294 if (BufferBytesLeft > 3) {
295 size_t BytesUsed = Fmt.print(OutBufCur, BufferBytesLeft);
297 // Common case is that we have plenty of space.
298 if (BytesUsed <= BufferBytesLeft) {
299 OutBufCur += BytesUsed;
303 // Otherwise, we overflowed and the return value tells us the size to try
305 NextBufferSize = BytesUsed;
308 // If we got here, we didn't have enough space in the output buffer for the
309 // string. Try printing into a SmallVector that is resized to have enough
310 // space. Iterate until we win.
311 SmallVector<char, 128> V;
314 V.resize(NextBufferSize);
316 // Try formatting into the SmallVector.
317 size_t BytesUsed = Fmt.print(V.data(), NextBufferSize);
319 // If BytesUsed fit into the vector, we win.
320 if (BytesUsed <= NextBufferSize)
321 return write(V.data(), BytesUsed);
323 // Otherwise, try again with a new size.
324 assert(BytesUsed > NextBufferSize && "Didn't grow buffer!?");
325 NextBufferSize = BytesUsed;
329 /// indent - Insert 'NumSpaces' spaces.
330 raw_ostream &raw_ostream::indent(unsigned NumSpaces) {
331 static const char Spaces[] = " "
335 // Usually the indentation is small, handle it with a fastpath.
336 if (NumSpaces < array_lengthof(Spaces))
337 return write(Spaces, NumSpaces);
340 unsigned NumToWrite = std::min(NumSpaces,
341 (unsigned)array_lengthof(Spaces)-1);
342 write(Spaces, NumToWrite);
343 NumSpaces -= NumToWrite;
349 //===----------------------------------------------------------------------===//
351 //===----------------------------------------------------------------------===//
353 // Out of line virtual method.
354 void format_object_base::home() {
357 //===----------------------------------------------------------------------===//
359 //===----------------------------------------------------------------------===//
361 /// raw_fd_ostream - Open the specified file for writing. If an error
362 /// occurs, information about the error is put into ErrorInfo, and the
363 /// stream should be immediately destroyed; the string will be empty
364 /// if no error occurred.
365 raw_fd_ostream::raw_fd_ostream(const char *Filename, std::string &ErrorInfo,
366 unsigned Flags) : Error(false), pos(0) {
367 assert(Filename != 0 && "Filename is null");
368 // Verify that we don't have both "append" and "excl".
369 assert((!(Flags & F_Excl) || !(Flags & F_Append)) &&
370 "Cannot specify both 'excl' and 'append' file creation flags!");
374 // Handle "-" as stdout. Note that when we do this, we consider ourself
375 // the owner of stdout. This means that we can do things like close the
376 // file descriptor when we're done and set the "binary" flag globally.
377 if (Filename[0] == '-' && Filename[1] == 0) {
379 // If user requested binary then put stdout into binary mode if
381 if (Flags & F_Binary)
382 sys::Program::ChangeStdoutToBinary();
383 // Close stdout when we're done, to detect any output errors.
388 int OpenFlags = O_WRONLY|O_CREAT;
390 if (Flags & F_Binary)
391 OpenFlags |= O_BINARY;
394 if (Flags & F_Append)
395 OpenFlags |= O_APPEND;
397 OpenFlags |= O_TRUNC;
401 while ((FD = open(Filename, OpenFlags, 0664)) < 0) {
402 if (errno != EINTR) {
403 ErrorInfo = "Error opening output file '" + std::string(Filename) + "'";
409 // Ok, we successfully opened the file, so it'll need to be closed.
413 raw_fd_ostream::~raw_fd_ostream() {
417 while (::close(FD) != 0)
418 if (errno != EINTR) {
424 // If there are any pending errors, report them now. Clients wishing
425 // to avoid report_fatal_error calls should check for errors with
426 // has_error() and clear the error flag with clear_error() before
427 // destructing raw_ostream objects which may have errors.
429 report_fatal_error("IO failure on output stream.");
433 void raw_fd_ostream::write_impl(const char *Ptr, size_t Size) {
434 assert(FD >= 0 && "File already closed.");
438 ssize_t ret = ::write(FD, Ptr, Size);
441 // If it's a recoverable error, swallow it and retry the write.
443 // Ideally we wouldn't ever see EAGAIN or EWOULDBLOCK here, since
444 // raw_ostream isn't designed to do non-blocking I/O. However, some
445 // programs, such as old versions of bjam, have mistakenly used
446 // O_NONBLOCK. For compatibility, emulate blocking semantics by
447 // spinning until the write succeeds. If you don't want spinning,
448 // don't use O_NONBLOCK file descriptors with raw_ostream.
449 if (errno == EINTR || errno == EAGAIN
451 || errno == EWOULDBLOCK
456 // Otherwise it's a non-recoverable error. Note it and quit.
461 // The write may have written some or all of the data. Update the
462 // size and buffer pointer to reflect the remainder that needs
463 // to be written. If there are no bytes left, we're done.
469 void raw_fd_ostream::close() {
473 while (::close(FD) != 0)
474 if (errno != EINTR) {
481 uint64_t raw_fd_ostream::seek(uint64_t off) {
483 pos = ::lseek(FD, off, SEEK_SET);
489 size_t raw_fd_ostream::preferred_buffer_size() const {
490 #if !defined(_MSC_VER) && !defined(__MINGW32__) && !defined(__minix)
491 // Windows and Minix have no st_blksize.
492 assert(FD >= 0 && "File not yet open!");
494 if (fstat(FD, &statbuf) != 0)
497 // If this is a terminal, don't use buffering. Line buffering
498 // would be a more traditional thing to do, but it's not worth
500 if (S_ISCHR(statbuf.st_mode) && isatty(FD))
502 // Return the preferred block size.
503 return statbuf.st_blksize;
505 return raw_ostream::preferred_buffer_size();
509 raw_ostream &raw_fd_ostream::changeColor(enum Colors colors, bool bold,
511 if (sys::Process::ColorNeedsFlush())
513 const char *colorcode =
514 (colors == SAVEDCOLOR) ? sys::Process::OutputBold(bg)
515 : sys::Process::OutputColor(colors, bold, bg);
517 size_t len = strlen(colorcode);
518 write(colorcode, len);
519 // don't account colors towards output characters
525 raw_ostream &raw_fd_ostream::resetColor() {
526 if (sys::Process::ColorNeedsFlush())
528 const char *colorcode = sys::Process::ResetColor();
530 size_t len = strlen(colorcode);
531 write(colorcode, len);
532 // don't account colors towards output characters
538 bool raw_fd_ostream::is_displayed() const {
539 return sys::Process::FileDescriptorIsDisplayed(FD);
542 //===----------------------------------------------------------------------===//
543 // outs(), errs(), nulls()
544 //===----------------------------------------------------------------------===//
546 /// outs() - This returns a reference to a raw_ostream for standard output.
547 /// Use it like: outs() << "foo" << "bar";
548 raw_ostream &llvm::outs() {
549 // Set buffer settings to model stdout behavior.
550 // Delete the file descriptor when the program exists, forcing error
551 // detection. If you don't want this behavior, don't use outs().
552 static raw_fd_ostream S(STDOUT_FILENO, true);
556 /// errs() - This returns a reference to a raw_ostream for standard error.
557 /// Use it like: errs() << "foo" << "bar";
558 raw_ostream &llvm::errs() {
559 // Set standard error to be unbuffered by default.
560 static raw_fd_ostream S(STDERR_FILENO, false, true);
564 /// nulls() - This returns a reference to a raw_ostream which discards output.
565 raw_ostream &llvm::nulls() {
566 static raw_null_ostream S;
571 //===----------------------------------------------------------------------===//
572 // raw_string_ostream
573 //===----------------------------------------------------------------------===//
575 raw_string_ostream::~raw_string_ostream() {
579 void raw_string_ostream::write_impl(const char *Ptr, size_t Size) {
580 OS.append(Ptr, Size);
583 //===----------------------------------------------------------------------===//
584 // raw_svector_ostream
585 //===----------------------------------------------------------------------===//
587 // The raw_svector_ostream implementation uses the SmallVector itself as the
588 // buffer for the raw_ostream. We guarantee that the raw_ostream buffer is
589 // always pointing past the end of the vector, but within the vector
590 // capacity. This allows raw_ostream to write directly into the correct place,
591 // and we only need to set the vector size when the data is flushed.
593 raw_svector_ostream::raw_svector_ostream(SmallVectorImpl<char> &O) : OS(O) {
594 // Set up the initial external buffer. We make sure that the buffer has at
595 // least 128 bytes free; raw_ostream itself only requires 64, but we want to
596 // make sure that we don't grow the buffer unnecessarily on destruction (when
597 // the data is flushed). See the FIXME below.
598 OS.reserve(OS.size() + 128);
599 SetBuffer(OS.end(), OS.capacity() - OS.size());
602 raw_svector_ostream::~raw_svector_ostream() {
603 // FIXME: Prevent resizing during this flush().
607 /// resync - This is called when the SmallVector we're appending to is changed
608 /// outside of the raw_svector_ostream's control. It is only safe to do this
609 /// if the raw_svector_ostream has previously been flushed.
610 void raw_svector_ostream::resync() {
611 assert(GetNumBytesInBuffer() == 0 && "Didn't flush before mutating vector");
613 if (OS.capacity() - OS.size() < 64)
614 OS.reserve(OS.capacity() * 2);
615 SetBuffer(OS.end(), OS.capacity() - OS.size());
618 void raw_svector_ostream::write_impl(const char *Ptr, size_t Size) {
619 // If we're writing bytes from the end of the buffer into the smallvector, we
620 // don't need to copy the bytes, just commit the bytes because they are
621 // already in the right place.
622 if (Ptr == OS.end()) {
623 assert(OS.size() + Size <= OS.capacity() && "Invalid write_impl() call!");
624 OS.set_size(OS.size() + Size);
626 assert(GetNumBytesInBuffer() == 0 &&
627 "Should be writing from buffer if some bytes in it");
628 // Otherwise, do copy the bytes.
629 OS.append(Ptr, Ptr+Size);
632 // Grow the vector if necessary.
633 if (OS.capacity() - OS.size() < 64)
634 OS.reserve(OS.capacity() * 2);
636 // Update the buffer position.
637 SetBuffer(OS.end(), OS.capacity() - OS.size());
640 uint64_t raw_svector_ostream::current_pos() const {
644 StringRef raw_svector_ostream::str() {
646 return StringRef(OS.begin(), OS.size());
649 //===----------------------------------------------------------------------===//
651 //===----------------------------------------------------------------------===//
653 raw_null_ostream::~raw_null_ostream() {
655 // ~raw_ostream asserts that the buffer is empty. This isn't necessary
656 // with raw_null_ostream, but it's better to have raw_null_ostream follow
657 // the rules than to change the rules just for raw_null_ostream.
662 void raw_null_ostream::write_impl(const char *Ptr, size_t Size) {
665 uint64_t raw_null_ostream::current_pos() const {
669 //===----------------------------------------------------------------------===//
671 //===----------------------------------------------------------------------===//
673 /// SetupRemoveOnSignal - This is a helper for tool_output_file's constructor
674 /// to allow the signal handlers to be installed before constructing the
675 /// base class raw_fd_ostream.
676 static const char *SetupRemoveOnSignal(const char *Filename) {
677 // Arrange for the file to be deleted if the process is killed.
678 if (strcmp(Filename, "-") != 0)
679 sys::RemoveFileOnSignal(sys::Path(Filename));
683 tool_output_file::tool_output_file(const char *filename, std::string &ErrorInfo,
685 : raw_fd_ostream(SetupRemoveOnSignal(filename), ErrorInfo, Flags),
687 Keep(!ErrorInfo.empty() /* If open fails, no cleanup is needed. */) {
690 tool_output_file::~tool_output_file() {
691 // Delete the file if the client hasn't told us not to.
692 if (!Keep && Filename != "-")
693 sys::Path(Filename).eraseFromDisk();