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"
20 class format_object_base;
22 class SmallVectorImpl;
24 /// raw_ostream - This class implements an extremely fast bulk output stream
25 /// that can *only* output to a stream. It does not support seeking, reopening,
26 /// rewinding, line buffered disciplines etc. It is a simple buffer that outputs
27 /// a chunk at a time.
30 // Do not implement. raw_ostream is noncopyable.
31 void operator=(const raw_ostream &);
32 raw_ostream(const raw_ostream &);
34 /// The buffer is handled in such a way that the buffer is
35 /// uninitialized, unbuffered, or out of space when OutBufCur >=
36 /// OutBufEnd. Thus a single comparison suffices to determine if we
37 /// need to take the slow path to write a single character.
39 /// The buffer is in one of three states:
40 /// 1. Unbuffered (BufferMode == Unbuffered)
41 /// 1. Uninitialized (BufferMode != Unbuffered && OutBufStart == 0).
42 /// 2. Buffered (BufferMode != Unbuffered && OutBufStart != 0 &&
43 /// OutBufEnd - OutBufStart >= 64).
45 /// If buffered, then the raw_ostream owns the buffer if (BufferMode ==
46 /// InternalBuffer); otherwise the buffer has been set via SetBuffer and is
47 /// managed by the subclass.
49 /// If a subclass installs an external buffer using SetBuffer then it can wait
50 /// for a \see write_impl() call to handle the data which has been put into
52 char *OutBufStart, *OutBufEnd, *OutBufCur;
60 /// Error This flag is true if an error of any kind has been detected.
65 // color order matches ANSI escape sequence, don't change
78 explicit raw_ostream(bool unbuffered=false)
79 : BufferMode(unbuffered ? Unbuffered : InternalBuffer), Error(false) {
80 // Start out ready to flush.
81 OutBufStart = OutBufEnd = OutBufCur = 0;
84 virtual ~raw_ostream();
86 /// tell - Return the current offset with the file.
87 uint64_t tell() { return current_pos() + GetNumBytesInBuffer(); }
89 /// has_error - Return the value of the flag in this raw_ostream indicating
90 /// whether an output error has been encountered.
91 bool has_error() const {
95 /// clear_error - Set the flag read by has_error() to false. If the error
96 /// flag is set at the time when this raw_ostream's destructor is called,
97 /// llvm_report_error is called to report the error. Use clear_error()
98 /// after handling the error to avoid this behavior.
103 //===--------------------------------------------------------------------===//
104 // Configuration Interface
105 //===--------------------------------------------------------------------===//
107 /// SetBuffered - Set the stream to be buffered, with an automatically
108 /// determined buffer size.
111 /// SetBufferSize - Set the stream to be buffered, using the
112 /// specified buffer size.
113 void SetBufferSize(size_t Size) {
115 SetBufferAndMode(new char[Size], Size, InternalBuffer);
118 size_t GetBufferSize() {
119 // If we're supposed to be buffered but haven't actually gotten around
120 // to allocating the buffer yet, return the value that would be used.
121 if (BufferMode != Unbuffered && OutBufStart == 0)
122 return preferred_buffer_size();
124 // Otherwise just return the size of the allocated buffer.
125 return OutBufEnd - OutBufStart;
128 /// SetUnbuffered - Set the stream to be unbuffered. When
129 /// unbuffered, the stream will flush after every write. This routine
130 /// will also flush the buffer immediately when the stream is being
131 /// set to unbuffered.
132 void SetUnbuffered() {
134 SetBufferAndMode(0, 0, Unbuffered);
137 size_t GetNumBytesInBuffer() const {
138 return OutBufCur - OutBufStart;
141 //===--------------------------------------------------------------------===//
142 // Data Output Interface
143 //===--------------------------------------------------------------------===//
146 if (OutBufCur != OutBufStart)
150 raw_ostream &operator<<(char C) {
151 if (OutBufCur >= OutBufEnd)
157 raw_ostream &operator<<(unsigned char C) {
158 if (OutBufCur >= OutBufEnd)
164 raw_ostream &operator<<(signed char C) {
165 if (OutBufCur >= OutBufEnd)
171 raw_ostream &operator<<(const StringRef &Str) {
172 // Inline fast path, particularly for strings with a known length.
173 size_t Size = Str.size();
175 // Make sure we can use the fast path.
176 if (OutBufCur+Size > OutBufEnd)
177 return write(Str.data(), Size);
179 memcpy(OutBufCur, Str.data(), Size);
184 raw_ostream &operator<<(const char *Str) {
185 // Inline fast path, particulary for constant strings where a sufficiently
186 // smart compiler will simplify strlen.
188 this->operator<<(StringRef(Str));
192 raw_ostream &operator<<(const std::string &Str) {
193 // Avoid the fast path, it would only increase code size for a marginal win.
194 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 this->operator<<(static_cast<unsigned long>(N));
208 raw_ostream &operator<<(int N) {
209 this->operator<<(static_cast<long>(N));
213 raw_ostream &operator<<(double N);
215 /// write_hex - Output \arg N in hexadecimal, without any prefix or padding.
216 raw_ostream &write_hex(unsigned long long N);
218 raw_ostream &write(unsigned char C);
219 raw_ostream &write(const char *Ptr, size_t Size);
221 // Formatted output, see the format() function in Support/Format.h.
222 raw_ostream &operator<<(const format_object_base &Fmt);
224 /// indent - Insert 'NumSpaces' spaces.
225 raw_ostream &indent(unsigned NumSpaces);
228 /// Changes the foreground color of text that will be output from this point
230 /// @param colors ANSI color to use, the special SAVEDCOLOR can be used to
231 /// change only the bold attribute, and keep colors untouched
232 /// @param bold bold/brighter text, default false
233 /// @param bg if true change the background, default: change foreground
234 /// @returns itself so it can be used within << invocations
235 virtual raw_ostream &changeColor(enum Colors colors, bool bold=false,
236 bool bg=false) { return *this; }
238 /// Resets the colors to terminal defaults. Call this when you are done
239 /// outputting colored text, or before program exit.
240 virtual raw_ostream &resetColor() { return *this; }
242 //===--------------------------------------------------------------------===//
243 // Subclass Interface
244 //===--------------------------------------------------------------------===//
247 /// write_impl - The is the piece of the class that is implemented
248 /// by subclasses. This writes the \args Size bytes starting at
249 /// \arg Ptr to the underlying stream.
251 /// This function is guaranteed to only be called at a point at which it is
252 /// safe for the subclass to install a new buffer via SetBuffer.
254 /// \arg Ptr - The start of the data to be written. For buffered streams this
255 /// is guaranteed to be the start of the buffer.
256 /// \arg Size - The number of bytes to be written.
258 /// \invariant { Size > 0 }
259 virtual void write_impl(const char *Ptr, size_t Size) = 0;
261 // An out of line virtual method to provide a home for the class vtable.
262 virtual void handle();
264 /// current_pos - Return the current position within the stream, not
265 /// counting the bytes currently in the buffer.
266 virtual uint64_t current_pos() = 0;
269 /// SetBuffer - Use the provided buffer as the raw_ostream buffer. This is
270 /// intended for use only by subclasses which can arrange for the output to go
271 /// directly into the desired output buffer, instead of being copied on each
273 void SetBuffer(char *BufferStart, size_t Size) {
274 SetBufferAndMode(BufferStart, Size, ExternalBuffer);
277 /// preferred_buffer_size - Return an efficient buffer size for the
278 /// underlying output mechanism.
279 virtual size_t preferred_buffer_size();
281 /// error_detected - Set the flag indicating that an output error has
282 /// been encountered.
283 void error_detected() { Error = true; }
285 /// getBufferStart - Return the beginning of the current stream buffer, or 0
286 /// if the stream is unbuffered.
287 const char *getBufferStart() const { return OutBufStart; }
289 //===--------------------------------------------------------------------===//
291 //===--------------------------------------------------------------------===//
293 /// SetBufferAndMode - Install the given buffer and mode.
294 void SetBufferAndMode(char *BufferStart, size_t Size, BufferKind Mode);
296 /// flush_nonempty - Flush the current buffer, which is known to be
297 /// non-empty. This outputs the currently buffered data and resets
298 /// the buffer to empty.
299 void flush_nonempty();
301 /// copy_to_buffer - Copy data into the buffer. Size must not be
302 /// greater than the number of unused bytes in the buffer.
303 void copy_to_buffer(const char *Ptr, size_t Size);
306 //===----------------------------------------------------------------------===//
307 // File Output Streams
308 //===----------------------------------------------------------------------===//
310 /// raw_fd_ostream - A raw_ostream that writes to a file descriptor.
312 class raw_fd_ostream : public raw_ostream {
317 /// write_impl - See raw_ostream::write_impl.
318 virtual void write_impl(const char *Ptr, size_t Size);
320 /// current_pos - Return the current position within the stream, not
321 /// counting the bytes currently in the buffer.
322 virtual uint64_t current_pos() { return pos; }
324 /// preferred_buffer_size - Determine an efficient buffer size.
325 virtual size_t preferred_buffer_size();
330 /// F_Force - When opening a file, this flag makes raw_fd_ostream overwrite
331 /// a file if it already exists instead of emitting an error. This may not
332 /// be specified with F_Append.
335 /// F_Append - When opening a file, if it already exists append to the
336 /// existing file instead of returning an error. This may not be specified
340 /// F_Binary - The file should be opened in binary mode on platforms that
341 /// support this distinction.
345 /// raw_fd_ostream - Open the specified file for writing. If an error occurs,
346 /// information about the error is put into ErrorInfo, and the stream should
347 /// be immediately destroyed; the string will be empty if no error occurred.
348 /// This allows optional flags to control how the file will be opened.
350 /// \param Filename - The file to open. If this is "-" then the
351 /// stream will use stdout instead.
352 raw_fd_ostream(const char *Filename, std::string &ErrorInfo,
355 /// raw_fd_ostream ctor - FD is the file descriptor that this writes to. If
356 /// ShouldClose is true, this closes the file when the stream is destroyed.
357 raw_fd_ostream(int fd, bool shouldClose,
358 bool unbuffered=false) : raw_ostream(unbuffered), FD(fd),
359 ShouldClose(shouldClose) {}
363 /// close - Manually flush the stream and close the file.
366 /// seek - Flushes the stream and repositions the underlying file descriptor
367 /// positition to the offset specified from the beginning of the file.
368 uint64_t seek(uint64_t off);
370 virtual raw_ostream &changeColor(enum Colors colors, bool bold=false,
372 virtual raw_ostream &resetColor();
375 /// raw_stdout_ostream - This is a stream that always prints to stdout.
377 class raw_stdout_ostream : public raw_fd_ostream {
378 // An out of line virtual method to provide a home for the class vtable.
379 virtual void handle();
381 raw_stdout_ostream();
384 /// raw_stderr_ostream - This is a stream that always prints to stderr.
386 class raw_stderr_ostream : public raw_fd_ostream {
387 // An out of line virtual method to provide a home for the class vtable.
388 virtual void handle();
390 raw_stderr_ostream();
393 /// outs() - This returns a reference to a raw_ostream for standard output.
394 /// Use it like: outs() << "foo" << "bar";
397 /// errs() - This returns a reference to a raw_ostream for standard error.
398 /// Use it like: errs() << "foo" << "bar";
401 /// nulls() - This returns a reference to a raw_ostream which simply discards
403 raw_ostream &nulls();
405 //===----------------------------------------------------------------------===//
406 // Output Stream Adaptors
407 //===----------------------------------------------------------------------===//
409 /// raw_string_ostream - A raw_ostream that writes to an std::string. This is a
410 /// simple adaptor class. This class does not encounter output errors.
411 class raw_string_ostream : public raw_ostream {
414 /// write_impl - See raw_ostream::write_impl.
415 virtual void write_impl(const char *Ptr, size_t Size);
417 /// current_pos - Return the current position within the stream, not
418 /// counting the bytes currently in the buffer.
419 virtual uint64_t current_pos() { return OS.size(); }
421 explicit raw_string_ostream(std::string &O) : OS(O) {}
422 ~raw_string_ostream();
424 /// str - Flushes the stream contents to the target string and returns
425 /// the string's reference.
432 /// raw_svector_ostream - A raw_ostream that writes to an SmallVector or
433 /// SmallString. This is a simple adaptor class. This class does not
434 /// encounter output errors.
435 class raw_svector_ostream : public raw_ostream {
436 SmallVectorImpl<char> &OS;
438 /// write_impl - See raw_ostream::write_impl.
439 virtual void write_impl(const char *Ptr, size_t Size);
441 /// current_pos - Return the current position within the stream, not
442 /// counting the bytes currently in the buffer.
443 virtual uint64_t current_pos();
445 /// Construct a new raw_svector_ostream.
447 /// \arg O - The vector to write to; this should generally have at least 128
448 /// bytes free to avoid any extraneous memory overhead.
449 explicit raw_svector_ostream(SmallVectorImpl<char> &O);
450 ~raw_svector_ostream();
452 /// str - Flushes the stream contents to the target vector and return a
453 /// StringRef for the vector contents.
457 /// raw_null_ostream - A raw_ostream that discards all output.
458 class raw_null_ostream : public raw_ostream {
459 /// write_impl - See raw_ostream::write_impl.
460 virtual void write_impl(const char *Ptr, size_t size);
462 /// current_pos - Return the current position within the stream, not
463 /// counting the bytes currently in the buffer.
464 virtual uint64_t current_pos();
467 explicit raw_null_ostream() {}
471 } // end llvm namespace