1 //===--- raw_ostream.h - Raw output stream ----------------------*- C++ -*-===//
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 file defines the raw_ostream class.
12 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_SUPPORT_RAW_OSTREAM_H
15 #define LLVM_SUPPORT_RAW_OSTREAM_H
17 #include "llvm/ADT/StringRef.h"
18 #include "llvm/System/DataTypes.h"
21 class format_object_base;
23 class SmallVectorImpl;
25 /// raw_ostream - This class implements an extremely fast bulk output stream
26 /// that can *only* output to a stream. It does not support seeking, reopening,
27 /// rewinding, line buffered disciplines etc. It is a simple buffer that outputs
28 /// a chunk at a time.
31 // Do not implement. raw_ostream is noncopyable.
32 void operator=(const raw_ostream &);
33 raw_ostream(const raw_ostream &);
35 /// The buffer is handled in such a way that the buffer is
36 /// uninitialized, unbuffered, or out of space when OutBufCur >=
37 /// OutBufEnd. Thus a single comparison suffices to determine if we
38 /// need to take the slow path to write a single character.
40 /// The buffer is in one of three states:
41 /// 1. Unbuffered (BufferMode == Unbuffered)
42 /// 1. Uninitialized (BufferMode != Unbuffered && OutBufStart == 0).
43 /// 2. Buffered (BufferMode != Unbuffered && OutBufStart != 0 &&
44 /// OutBufEnd - OutBufStart >= 1).
46 /// If buffered, then the raw_ostream owns the buffer if (BufferMode ==
47 /// InternalBuffer); otherwise the buffer has been set via SetBuffer and is
48 /// managed by the subclass.
50 /// If a subclass installs an external buffer using SetBuffer then it can wait
51 /// for a \see write_impl() call to handle the data which has been put into
53 char *OutBufStart, *OutBufEnd, *OutBufCur;
61 /// Error This flag is true if an error of any kind has been detected.
66 // color order matches ANSI escape sequence, don't change
79 explicit raw_ostream(bool unbuffered=false)
80 : BufferMode(unbuffered ? Unbuffered : InternalBuffer), Error(false) {
81 // Start out ready to flush.
82 OutBufStart = OutBufEnd = OutBufCur = 0;
85 virtual ~raw_ostream();
87 /// tell - Return the current offset with the file.
88 uint64_t tell() const { return current_pos() + GetNumBytesInBuffer(); }
90 /// has_error - Return the value of the flag in this raw_ostream indicating
91 /// whether an output error has been encountered.
92 /// This doesn't implicitly flush any pending output.
93 bool has_error() const {
97 /// clear_error - Set the flag read by has_error() to false. If the error
98 /// flag is set at the time when this raw_ostream's destructor is called,
99 /// report_fatal_error is called to report the error. Use clear_error()
100 /// after handling the error to avoid this behavior.
105 //===--------------------------------------------------------------------===//
106 // Configuration Interface
107 //===--------------------------------------------------------------------===//
109 /// SetBuffered - Set the stream to be buffered, with an automatically
110 /// determined buffer size.
113 /// SetBufferSize - Set the stream to be buffered, using the
114 /// specified buffer size.
115 void SetBufferSize(size_t Size) {
117 SetBufferAndMode(new char[Size], Size, InternalBuffer);
120 size_t GetBufferSize() const {
121 // If we're supposed to be buffered but haven't actually gotten around
122 // to allocating the buffer yet, return the value that would be used.
123 if (BufferMode != Unbuffered && OutBufStart == 0)
124 return preferred_buffer_size();
126 // Otherwise just return the size of the allocated buffer.
127 return OutBufEnd - OutBufStart;
130 /// SetUnbuffered - Set the stream to be unbuffered. When
131 /// unbuffered, the stream will flush after every write. This routine
132 /// will also flush the buffer immediately when the stream is being
133 /// set to unbuffered.
134 void SetUnbuffered() {
136 SetBufferAndMode(0, 0, Unbuffered);
139 size_t GetNumBytesInBuffer() const {
140 return OutBufCur - OutBufStart;
143 //===--------------------------------------------------------------------===//
144 // Data Output Interface
145 //===--------------------------------------------------------------------===//
148 if (OutBufCur != OutBufStart)
152 raw_ostream &operator<<(char C) {
153 if (OutBufCur >= OutBufEnd)
159 raw_ostream &operator<<(unsigned char C) {
160 if (OutBufCur >= OutBufEnd)
166 raw_ostream &operator<<(signed char C) {
167 if (OutBufCur >= OutBufEnd)
173 raw_ostream &operator<<(StringRef Str) {
174 // Inline fast path, particularly for strings with a known length.
175 size_t Size = Str.size();
177 // Make sure we can use the fast path.
178 if (OutBufCur+Size > OutBufEnd)
179 return write(Str.data(), Size);
181 memcpy(OutBufCur, Str.data(), Size);
186 raw_ostream &operator<<(const char *Str) {
187 // Inline fast path, particulary for constant strings where a sufficiently
188 // smart compiler will simplify strlen.
190 return this->operator<<(StringRef(Str));
193 raw_ostream &operator<<(const std::string &Str) {
194 // Avoid the fast path, it would only increase code size for a marginal win.
195 return write(Str.data(), Str.length());
198 raw_ostream &operator<<(unsigned long N);
199 raw_ostream &operator<<(long N);
200 raw_ostream &operator<<(unsigned long long N);
201 raw_ostream &operator<<(long long N);
202 raw_ostream &operator<<(const void *P);
203 raw_ostream &operator<<(unsigned int N) {
204 return this->operator<<(static_cast<unsigned long>(N));
207 raw_ostream &operator<<(int N) {
208 return this->operator<<(static_cast<long>(N));
211 raw_ostream &operator<<(double N);
213 /// write_hex - Output \arg N in hexadecimal, without any prefix or padding.
214 raw_ostream &write_hex(unsigned long long N);
216 /// write_escaped - Output \arg Str, turning '\\', '\t', '\n', '"', and
217 /// anything that doesn't satisfy std::isprint into an escape sequence.
218 raw_ostream &write_escaped(StringRef Str);
220 raw_ostream &write(unsigned char C);
221 raw_ostream &write(const char *Ptr, size_t Size);
223 // Formatted output, see the format() function in Support/Format.h.
224 raw_ostream &operator<<(const format_object_base &Fmt);
226 /// indent - Insert 'NumSpaces' spaces.
227 raw_ostream &indent(unsigned NumSpaces);
230 /// Changes the foreground color of text that will be output from this point
232 /// @param colors ANSI color to use, the special SAVEDCOLOR can be used to
233 /// change only the bold attribute, and keep colors untouched
234 /// @param bold bold/brighter text, default false
235 /// @param bg if true change the background, default: change foreground
236 /// @returns itself so it can be used within << invocations
237 virtual raw_ostream &changeColor(enum Colors, bool = false, bool = false) {
240 /// Resets the colors to terminal defaults. Call this when you are done
241 /// outputting colored text, or before program exit.
242 virtual raw_ostream &resetColor() { return *this; }
244 /// This function determines if this stream is connected to a "tty" or
245 /// "console" window. That is, the output would be displayed to the user
246 /// rather than being put on a pipe or stored in a file.
247 virtual bool is_displayed() const { return false; }
249 //===--------------------------------------------------------------------===//
250 // Subclass Interface
251 //===--------------------------------------------------------------------===//
254 /// write_impl - The is the piece of the class that is implemented
255 /// by subclasses. This writes the \args Size bytes starting at
256 /// \arg Ptr to the underlying stream.
258 /// This function is guaranteed to only be called at a point at which it is
259 /// safe for the subclass to install a new buffer via SetBuffer.
261 /// \arg Ptr - The start of the data to be written. For buffered streams this
262 /// is guaranteed to be the start of the buffer.
263 /// \arg Size - The number of bytes to be written.
265 /// \invariant { Size > 0 }
266 virtual void write_impl(const char *Ptr, size_t Size) = 0;
268 // An out of line virtual method to provide a home for the class vtable.
269 virtual void handle();
271 /// current_pos - Return the current position within the stream, not
272 /// counting the bytes currently in the buffer.
273 virtual uint64_t current_pos() const = 0;
276 /// SetBuffer - Use the provided buffer as the raw_ostream buffer. This is
277 /// intended for use only by subclasses which can arrange for the output to go
278 /// directly into the desired output buffer, instead of being copied on each
280 void SetBuffer(char *BufferStart, size_t Size) {
281 SetBufferAndMode(BufferStart, Size, ExternalBuffer);
284 /// preferred_buffer_size - Return an efficient buffer size for the
285 /// underlying output mechanism.
286 virtual size_t preferred_buffer_size() const;
288 /// error_detected - Set the flag indicating that an output error has
289 /// been encountered.
290 void error_detected() { Error = true; }
292 /// getBufferStart - Return the beginning of the current stream buffer, or 0
293 /// if the stream is unbuffered.
294 const char *getBufferStart() const { return OutBufStart; }
296 //===--------------------------------------------------------------------===//
298 //===--------------------------------------------------------------------===//
300 /// SetBufferAndMode - Install the given buffer and mode.
301 void SetBufferAndMode(char *BufferStart, size_t Size, BufferKind Mode);
303 /// flush_nonempty - Flush the current buffer, which is known to be
304 /// non-empty. This outputs the currently buffered data and resets
305 /// the buffer to empty.
306 void flush_nonempty();
308 /// copy_to_buffer - Copy data into the buffer. Size must not be
309 /// greater than the number of unused bytes in the buffer.
310 void copy_to_buffer(const char *Ptr, size_t Size);
313 //===----------------------------------------------------------------------===//
314 // File Output Streams
315 //===----------------------------------------------------------------------===//
317 /// raw_fd_ostream - A raw_ostream that writes to a file descriptor.
319 class raw_fd_ostream : public raw_ostream {
324 /// write_impl - See raw_ostream::write_impl.
325 virtual void write_impl(const char *Ptr, size_t Size);
327 /// current_pos - Return the current position within the stream, not
328 /// counting the bytes currently in the buffer.
329 virtual uint64_t current_pos() const { return pos; }
331 /// preferred_buffer_size - Determine an efficient buffer size.
332 virtual size_t preferred_buffer_size() const;
337 /// F_Excl - When opening a file, this flag makes raw_fd_ostream
338 /// report an error if the file already exists.
341 /// F_Append - When opening a file, if it already exists append to the
342 /// existing file instead of returning an error. This may not be specified
346 /// F_Binary - The file should be opened in binary mode on platforms that
347 /// make this distinction.
351 /// raw_fd_ostream - Open the specified file for writing. If an error occurs,
352 /// information about the error is put into ErrorInfo, and the stream should
353 /// be immediately destroyed; the string will be empty if no error occurred.
354 /// This allows optional flags to control how the file will be opened.
356 /// As a special case, if Filename is "-", then the stream will use
357 /// STDOUT_FILENO instead of opening a file. Note that it will still consider
358 /// itself to own the file descriptor. In particular, it will close the
359 /// file descriptor when it is done (this is necessary to detect
361 raw_fd_ostream(const char *Filename, std::string &ErrorInfo,
364 /// raw_fd_ostream ctor - FD is the file descriptor that this writes to. If
365 /// ShouldClose is true, this closes the file when the stream is destroyed.
366 raw_fd_ostream(int fd, bool shouldClose,
367 bool unbuffered=false) : raw_ostream(unbuffered), FD(fd),
368 ShouldClose(shouldClose) {}
372 /// close - Manually flush the stream and close the file.
375 /// seek - Flushes the stream and repositions the underlying file descriptor
376 /// positition to the offset specified from the beginning of the file.
377 uint64_t seek(uint64_t off);
379 virtual raw_ostream &changeColor(enum Colors colors, bool bold=false,
381 virtual raw_ostream &resetColor();
383 virtual bool is_displayed() const;
386 /// raw_stdout_ostream - This is a stream that always prints to stdout.
388 class raw_stdout_ostream : public raw_fd_ostream {
389 // An out of line virtual method to provide a home for the class vtable.
390 virtual void handle();
392 raw_stdout_ostream();
395 /// raw_stderr_ostream - This is a stream that always prints to stderr.
397 class raw_stderr_ostream : public raw_fd_ostream {
398 // An out of line virtual method to provide a home for the class vtable.
399 virtual void handle();
401 raw_stderr_ostream();
404 /// outs() - This returns a reference to a raw_ostream for standard output.
405 /// Use it like: outs() << "foo" << "bar";
408 /// errs() - This returns a reference to a raw_ostream for standard error.
409 /// Use it like: errs() << "foo" << "bar";
412 /// nulls() - This returns a reference to a raw_ostream which simply discards
414 raw_ostream &nulls();
416 //===----------------------------------------------------------------------===//
417 // Output Stream Adaptors
418 //===----------------------------------------------------------------------===//
420 /// raw_string_ostream - A raw_ostream that writes to an std::string. This is a
421 /// simple adaptor class. This class does not encounter output errors.
422 class raw_string_ostream : public raw_ostream {
425 /// write_impl - See raw_ostream::write_impl.
426 virtual void write_impl(const char *Ptr, size_t Size);
428 /// current_pos - Return the current position within the stream, not
429 /// counting the bytes currently in the buffer.
430 virtual uint64_t current_pos() const { return OS.size(); }
432 explicit raw_string_ostream(std::string &O) : OS(O) {}
433 ~raw_string_ostream();
435 /// str - Flushes the stream contents to the target string and returns
436 /// the string's reference.
443 /// raw_svector_ostream - A raw_ostream that writes to an SmallVector or
444 /// SmallString. This is a simple adaptor class. This class does not
445 /// encounter output errors.
446 class raw_svector_ostream : public raw_ostream {
447 SmallVectorImpl<char> &OS;
449 /// write_impl - See raw_ostream::write_impl.
450 virtual void write_impl(const char *Ptr, size_t Size);
452 /// current_pos - Return the current position within the stream, not
453 /// counting the bytes currently in the buffer.
454 virtual uint64_t current_pos() const;
456 /// Construct a new raw_svector_ostream.
458 /// \arg O - The vector to write to; this should generally have at least 128
459 /// bytes free to avoid any extraneous memory overhead.
460 explicit raw_svector_ostream(SmallVectorImpl<char> &O);
461 ~raw_svector_ostream();
463 /// resync - This is called when the SmallVector we're appending to is changed
464 /// outside of the raw_svector_ostream's control. It is only safe to do this
465 /// if the raw_svector_ostream has previously been flushed.
468 /// str - Flushes the stream contents to the target vector and return a
469 /// StringRef for the vector contents.
473 /// raw_null_ostream - A raw_ostream that discards all output.
474 class raw_null_ostream : public raw_ostream {
475 /// write_impl - See raw_ostream::write_impl.
476 virtual void write_impl(const char *Ptr, size_t size);
478 /// current_pos - Return the current position within the stream, not
479 /// counting the bytes currently in the buffer.
480 virtual uint64_t current_pos() const;
483 explicit raw_null_ostream() {}
487 } // end llvm namespace