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;
61 // If there are any pending errors, report them now. Clients wishing
62 // to avoid report_fatal_error calls should check for errors with
63 // has_error() and clear the error flag with clear_error() before
64 // destructing raw_ostream objects which may have errors.
66 report_fatal_error("IO failure on output stream.");
69 // An out of line virtual method to provide a home for the class vtable.
70 void raw_ostream::handle() {}
72 size_t raw_ostream::preferred_buffer_size() const {
73 // BUFSIZ is intended to be a reasonable default.
77 void raw_ostream::SetBuffered() {
78 // Ask the subclass to determine an appropriate buffer size.
79 if (size_t Size = preferred_buffer_size())
82 // It may return 0, meaning this stream should be unbuffered.
86 void raw_ostream::SetBufferAndMode(char *BufferStart, size_t Size,
88 assert(((Mode == Unbuffered && BufferStart == 0 && Size == 0) ||
89 (Mode != Unbuffered && BufferStart && Size)) &&
90 "stream must be unbuffered or have at least one byte");
91 // Make sure the current buffer is free of content (we can't flush here; the
92 // child buffer management logic will be in write_impl).
93 assert(GetNumBytesInBuffer() == 0 && "Current buffer is non-empty!");
95 if (BufferMode == InternalBuffer)
96 delete [] OutBufStart;
97 OutBufStart = BufferStart;
98 OutBufEnd = OutBufStart+Size;
99 OutBufCur = OutBufStart;
102 assert(OutBufStart <= OutBufEnd && "Invalid size!");
105 raw_ostream &raw_ostream::operator<<(unsigned long N) {
106 // Zero is a special case.
110 char NumberBuffer[20];
111 char *EndPtr = NumberBuffer+sizeof(NumberBuffer);
112 char *CurPtr = EndPtr;
115 *--CurPtr = '0' + char(N % 10);
118 return write(CurPtr, EndPtr-CurPtr);
121 raw_ostream &raw_ostream::operator<<(long N) {
127 return this->operator<<(static_cast<unsigned long>(N));
130 raw_ostream &raw_ostream::operator<<(unsigned long long N) {
131 // Output using 32-bit div/mod when possible.
132 if (N == static_cast<unsigned long>(N))
133 return this->operator<<(static_cast<unsigned long>(N));
135 char NumberBuffer[20];
136 char *EndPtr = NumberBuffer+sizeof(NumberBuffer);
137 char *CurPtr = EndPtr;
140 *--CurPtr = '0' + char(N % 10);
143 return write(CurPtr, EndPtr-CurPtr);
146 raw_ostream &raw_ostream::operator<<(long long N) {
149 // Avoid undefined behavior on INT64_MIN with a cast.
150 N = -(unsigned long long)N;
153 return this->operator<<(static_cast<unsigned long long>(N));
156 raw_ostream &raw_ostream::write_hex(unsigned long long N) {
157 // Zero is a special case.
161 char NumberBuffer[20];
162 char *EndPtr = NumberBuffer+sizeof(NumberBuffer);
163 char *CurPtr = EndPtr;
166 uintptr_t x = N % 16;
167 *--CurPtr = (x < 10 ? '0' + x : 'a' + x - 10);
171 return write(CurPtr, EndPtr-CurPtr);
174 raw_ostream &raw_ostream::write_escaped(StringRef Str) {
175 for (unsigned i = 0, e = Str.size(); i != e; ++i) {
176 unsigned char c = Str[i];
180 *this << '\\' << '\\';
183 *this << '\\' << 't';
186 *this << '\\' << 'n';
189 *this << '\\' << '"';
192 if (std::isprint(c)) {
197 // Always expand to a 3-character octal escape.
199 *this << char('0' + ((c >> 6) & 7));
200 *this << char('0' + ((c >> 3) & 7));
201 *this << char('0' + ((c >> 0) & 7));
208 raw_ostream &raw_ostream::operator<<(const void *P) {
211 return write_hex((uintptr_t) P);
214 raw_ostream &raw_ostream::operator<<(double N) {
215 return this->operator<<(format("%e", N));
220 void raw_ostream::flush_nonempty() {
221 assert(OutBufCur > OutBufStart && "Invalid call to flush_nonempty.");
222 size_t Length = OutBufCur - OutBufStart;
223 OutBufCur = OutBufStart;
224 write_impl(OutBufStart, Length);
227 raw_ostream &raw_ostream::write(unsigned char C) {
228 // Group exceptional cases into a single branch.
229 if (BUILTIN_EXPECT(OutBufCur >= OutBufEnd, false)) {
230 if (BUILTIN_EXPECT(!OutBufStart, false)) {
231 if (BufferMode == Unbuffered) {
232 write_impl(reinterpret_cast<char*>(&C), 1);
235 // Set up a buffer and start over.
247 raw_ostream &raw_ostream::write(const char *Ptr, size_t Size) {
248 // Group exceptional cases into a single branch.
249 if (BUILTIN_EXPECT(OutBufCur+Size > OutBufEnd, false)) {
250 if (BUILTIN_EXPECT(!OutBufStart, false)) {
251 if (BufferMode == Unbuffered) {
252 write_impl(Ptr, Size);
255 // Set up a buffer and start over.
257 return write(Ptr, Size);
260 // Write out the data in buffer-sized blocks until the remainder
261 // fits within the buffer.
263 size_t NumBytes = OutBufEnd - OutBufCur;
264 copy_to_buffer(Ptr, NumBytes);
268 } while (OutBufCur+Size > OutBufEnd);
271 copy_to_buffer(Ptr, Size);
276 void raw_ostream::copy_to_buffer(const char *Ptr, size_t Size) {
277 assert(Size <= size_t(OutBufEnd - OutBufCur) && "Buffer overrun!");
279 // Handle short strings specially, memcpy isn't very good at very short
282 case 4: OutBufCur[3] = Ptr[3]; // FALL THROUGH
283 case 3: OutBufCur[2] = Ptr[2]; // FALL THROUGH
284 case 2: OutBufCur[1] = Ptr[1]; // FALL THROUGH
285 case 1: OutBufCur[0] = Ptr[0]; // FALL THROUGH
288 memcpy(OutBufCur, Ptr, Size);
296 raw_ostream &raw_ostream::operator<<(const format_object_base &Fmt) {
297 // If we have more than a few bytes left in our output buffer, try
298 // formatting directly onto its end.
299 size_t NextBufferSize = 127;
300 size_t BufferBytesLeft = OutBufEnd - OutBufCur;
301 if (BufferBytesLeft > 3) {
302 size_t BytesUsed = Fmt.print(OutBufCur, BufferBytesLeft);
304 // Common case is that we have plenty of space.
305 if (BytesUsed <= BufferBytesLeft) {
306 OutBufCur += BytesUsed;
310 // Otherwise, we overflowed and the return value tells us the size to try
312 NextBufferSize = BytesUsed;
315 // If we got here, we didn't have enough space in the output buffer for the
316 // string. Try printing into a SmallVector that is resized to have enough
317 // space. Iterate until we win.
318 SmallVector<char, 128> V;
321 V.resize(NextBufferSize);
323 // Try formatting into the SmallVector.
324 size_t BytesUsed = Fmt.print(V.data(), NextBufferSize);
326 // If BytesUsed fit into the vector, we win.
327 if (BytesUsed <= NextBufferSize)
328 return write(V.data(), BytesUsed);
330 // Otherwise, try again with a new size.
331 assert(BytesUsed > NextBufferSize && "Didn't grow buffer!?");
332 NextBufferSize = BytesUsed;
336 /// indent - Insert 'NumSpaces' spaces.
337 raw_ostream &raw_ostream::indent(unsigned NumSpaces) {
338 static const char Spaces[] = " "
342 // Usually the indentation is small, handle it with a fastpath.
343 if (NumSpaces < array_lengthof(Spaces))
344 return write(Spaces, NumSpaces);
347 unsigned NumToWrite = std::min(NumSpaces,
348 (unsigned)array_lengthof(Spaces)-1);
349 write(Spaces, NumToWrite);
350 NumSpaces -= NumToWrite;
356 //===----------------------------------------------------------------------===//
358 //===----------------------------------------------------------------------===//
360 // Out of line virtual method.
361 void format_object_base::home() {
364 //===----------------------------------------------------------------------===//
366 //===----------------------------------------------------------------------===//
368 /// raw_fd_ostream - Open the specified file for writing. If an error
369 /// occurs, information about the error is put into ErrorInfo, and the
370 /// stream should be immediately destroyed; the string will be empty
371 /// if no error occurred.
372 raw_fd_ostream::raw_fd_ostream(const char *Filename, std::string &ErrorInfo,
373 unsigned Flags) : pos(0) {
374 assert(Filename != 0 && "Filename is null");
375 // Verify that we don't have both "append" and "excl".
376 assert((!(Flags & F_Excl) || !(Flags & F_Append)) &&
377 "Cannot specify both 'excl' and 'append' file creation flags!");
381 // Handle "-" as stdout. Note that when we do this, we consider ourself
382 // the owner of stdout. This means that we can do things like close the
383 // file descriptor when we're done and set the "binary" flag globally.
384 if (Filename[0] == '-' && Filename[1] == 0) {
386 // If user requested binary then put stdout into binary mode if
388 if (Flags & F_Binary)
389 sys::Program::ChangeStdoutToBinary();
390 // Close stdout when we're done, to detect any output errors.
395 int OpenFlags = O_WRONLY|O_CREAT;
397 if (Flags & F_Binary)
398 OpenFlags |= O_BINARY;
401 if (Flags & F_Append)
402 OpenFlags |= O_APPEND;
404 OpenFlags |= O_TRUNC;
408 while ((FD = open(Filename, OpenFlags, 0664)) < 0) {
409 if (errno != EINTR) {
410 ErrorInfo = "Error opening output file '" + std::string(Filename) + "'";
416 // Ok, we successfully opened the file, so it'll need to be closed.
420 raw_fd_ostream::~raw_fd_ostream() {
424 while (::close(FD) != 0)
425 if (errno != EINTR) {
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 // raw_stdout/err_ostream
543 //===----------------------------------------------------------------------===//
545 // Set buffer settings to model stdout and stderr behavior.
546 // Set standard error to be unbuffered by default.
547 raw_stdout_ostream::raw_stdout_ostream():raw_fd_ostream(STDOUT_FILENO, false) {}
548 raw_stderr_ostream::raw_stderr_ostream():raw_fd_ostream(STDERR_FILENO, false,
551 // An out of line virtual method to provide a home for the class vtable.
552 void raw_stdout_ostream::handle() {}
553 void raw_stderr_ostream::handle() {}
555 /// outs() - This returns a reference to a raw_ostream for standard output.
556 /// Use it like: outs() << "foo" << "bar";
557 raw_ostream &llvm::outs() {
558 static raw_stdout_ostream S;
562 /// errs() - This returns a reference to a raw_ostream for standard error.
563 /// Use it like: errs() << "foo" << "bar";
564 raw_ostream &llvm::errs() {
565 static raw_stderr_ostream S;
569 /// nulls() - This returns a reference to a raw_ostream which discards output.
570 raw_ostream &llvm::nulls() {
571 static raw_null_ostream S;
576 //===----------------------------------------------------------------------===//
577 // raw_string_ostream
578 //===----------------------------------------------------------------------===//
580 raw_string_ostream::~raw_string_ostream() {
584 void raw_string_ostream::write_impl(const char *Ptr, size_t Size) {
585 OS.append(Ptr, Size);
588 //===----------------------------------------------------------------------===//
589 // raw_svector_ostream
590 //===----------------------------------------------------------------------===//
592 // The raw_svector_ostream implementation uses the SmallVector itself as the
593 // buffer for the raw_ostream. We guarantee that the raw_ostream buffer is
594 // always pointing past the end of the vector, but within the vector
595 // capacity. This allows raw_ostream to write directly into the correct place,
596 // and we only need to set the vector size when the data is flushed.
598 raw_svector_ostream::raw_svector_ostream(SmallVectorImpl<char> &O) : OS(O) {
599 // Set up the initial external buffer. We make sure that the buffer has at
600 // least 128 bytes free; raw_ostream itself only requires 64, but we want to
601 // make sure that we don't grow the buffer unnecessarily on destruction (when
602 // the data is flushed). See the FIXME below.
603 OS.reserve(OS.size() + 128);
604 SetBuffer(OS.end(), OS.capacity() - OS.size());
607 raw_svector_ostream::~raw_svector_ostream() {
608 // FIXME: Prevent resizing during this flush().
612 /// resync - This is called when the SmallVector we're appending to is changed
613 /// outside of the raw_svector_ostream's control. It is only safe to do this
614 /// if the raw_svector_ostream has previously been flushed.
615 void raw_svector_ostream::resync() {
616 assert(GetNumBytesInBuffer() == 0 && "Didn't flush before mutating vector");
618 if (OS.capacity() - OS.size() < 64)
619 OS.reserve(OS.capacity() * 2);
620 SetBuffer(OS.end(), OS.capacity() - OS.size());
623 void raw_svector_ostream::write_impl(const char *Ptr, size_t Size) {
624 // If we're writing bytes from the end of the buffer into the smallvector, we
625 // don't need to copy the bytes, just commit the bytes because they are
626 // already in the right place.
627 if (Ptr == OS.end()) {
628 assert(OS.size() + Size <= OS.capacity() && "Invalid write_impl() call!");
629 OS.set_size(OS.size() + Size);
631 assert(GetNumBytesInBuffer() == 0 &&
632 "Should be writing from buffer if some bytes in it");
633 // Otherwise, do copy the bytes.
634 OS.append(Ptr, Ptr+Size);
637 // Grow the vector if necessary.
638 if (OS.capacity() - OS.size() < 64)
639 OS.reserve(OS.capacity() * 2);
641 // Update the buffer position.
642 SetBuffer(OS.end(), OS.capacity() - OS.size());
645 uint64_t raw_svector_ostream::current_pos() const {
649 StringRef raw_svector_ostream::str() {
651 return StringRef(OS.begin(), OS.size());
654 //===----------------------------------------------------------------------===//
656 //===----------------------------------------------------------------------===//
658 raw_null_ostream::~raw_null_ostream() {
660 // ~raw_ostream asserts that the buffer is empty. This isn't necessary
661 // with raw_null_ostream, but it's better to have raw_null_ostream follow
662 // the rules than to change the rules just for raw_null_ostream.
667 void raw_null_ostream::write_impl(const char *Ptr, size_t Size) {
670 uint64_t raw_null_ostream::current_pos() const {
674 //===----------------------------------------------------------------------===//
676 //===----------------------------------------------------------------------===//
678 /// SetupRemoveOnSignal - This is a helper for tool_output_file's constructor
679 /// to allow the signal handlers to be installed before constructing the
680 /// base class raw_fd_ostream.
681 static const char *SetupRemoveOnSignal(const char *Filename) {
682 // Arrange for the file to be deleted if the process is killed.
683 if (strcmp(Filename, "-") != 0)
684 sys::RemoveFileOnSignal(sys::Path(Filename));
688 tool_output_file::tool_output_file(const char *filename, std::string &ErrorInfo,
690 : raw_fd_ostream(SetupRemoveOnSignal(filename), ErrorInfo, Flags),
692 Keep(!ErrorInfo.empty() /* If open fails, no cleanup is needed. */) {
695 tool_output_file::~tool_output_file() {
696 // Delete the file if the client hasn't told us not to.
697 if (!Keep && Filename != "-")
698 sys::Path(Filename).eraseFromDisk();