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/StringExtras.h"
18 #include "llvm/ADT/StringRef.h"
25 class format_object_base;
27 class SmallVectorImpl;
29 /// raw_ostream - This class implements an extremely fast bulk output stream
30 /// that can *only* output to a stream. It does not support seeking, reopening,
31 /// rewinding, line buffered disciplines etc. It is a simple buffer that outputs
32 /// a chunk at a time.
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 (Unbuffered == true)
42 /// 1. Uninitialized (Unbuffered == false && OutBufStart == 0).
43 /// 2. Buffered (Unbuffered == false && OutBufStart != 0 &&
44 /// OutBufEnd - OutBufStart >= 64).
45 char *OutBufStart, *OutBufEnd, *OutBufCur;
48 /// Error This flag is true if an error of any kind has been detected.
53 // color order matches ANSI escape sequence, don't change
66 explicit raw_ostream(bool unbuffered=false)
67 : Unbuffered(unbuffered), Error(false) {
68 // Start out ready to flush.
69 OutBufStart = OutBufEnd = OutBufCur = 0;
72 virtual ~raw_ostream();
74 /// tell - Return the current offset with the file.
75 uint64_t tell() { return current_pos() + GetNumBytesInBuffer(); }
77 /// has_error - Return the value of the flag in this raw_ostream indicating
78 /// whether an output error has been encountered.
79 bool has_error() const {
83 /// clear_error - Set the flag read by has_error() to false. If the error
84 /// flag is set at the time when this raw_ostream's destructor is called,
85 /// llvm_report_error is called to report the error. Use clear_error()
86 /// after handling the error to avoid this behavior.
91 //===--------------------------------------------------------------------===//
92 // Configuration Interface
93 //===--------------------------------------------------------------------===//
95 /// SetBufferSize - Set the internal buffer size to the specified amount
96 /// instead of the default.
97 void SetBufferSize(size_t Size=4096) {
99 "Buffer size must be somewhat large for invariants to hold");
102 delete [] OutBufStart;
103 OutBufStart = new char[Size];
104 OutBufEnd = OutBufStart+Size;
105 OutBufCur = OutBufStart;
109 size_t GetBufferSize() const {
110 return OutBufEnd - OutBufStart;
113 /// SetUnbuffered - Set the streams buffering status. When
114 /// unbuffered the stream will flush after every write. This routine
115 /// will also flush the buffer immediately when the stream is being
116 /// set to unbuffered.
117 void SetUnbuffered() {
120 delete [] OutBufStart;
121 OutBufStart = OutBufEnd = OutBufCur = 0;
125 size_t GetNumBytesInBuffer() const {
126 return OutBufCur - OutBufStart;
129 //===--------------------------------------------------------------------===//
130 // Data Output Interface
131 //===--------------------------------------------------------------------===//
134 if (OutBufCur != OutBufStart)
138 raw_ostream &operator<<(char C) {
139 if (OutBufCur >= OutBufEnd)
145 raw_ostream &operator<<(unsigned char C) {
146 if (OutBufCur >= OutBufEnd)
152 raw_ostream &operator<<(signed char C) {
153 if (OutBufCur >= OutBufEnd)
159 raw_ostream &operator<<(const StringRef &Str) {
160 // Inline fast path, particularly for strings with a known length.
161 size_t Size = Str.size();
163 // Make sure we can use the fast path.
164 if (OutBufCur+Size > OutBufEnd)
165 return write(Str.data(), Size);
167 memcpy(OutBufCur, Str.data(), Size);
172 raw_ostream &operator<<(const char *Str) {
173 // Inline fast path, particulary for constant strings where a sufficiently
174 // smart compiler will simplify strlen.
176 this->operator<<(StringRef(Str));
180 raw_ostream &operator<<(const std::string& Str) {
181 write(Str.data(), Str.length());
185 raw_ostream &operator<<(unsigned long N);
186 raw_ostream &operator<<(long N);
187 raw_ostream &operator<<(unsigned long long N);
188 raw_ostream &operator<<(long long N);
189 raw_ostream &operator<<(const void *P);
190 raw_ostream &operator<<(unsigned int N) {
191 this->operator<<(static_cast<unsigned long>(N));
195 raw_ostream &operator<<(int N) {
196 this->operator<<(static_cast<long>(N));
200 raw_ostream &operator<<(double N) {
201 this->operator<<(ftostr(N));
205 /// write_hex - Output \arg N in hexadecimal, without any prefix or padding.
206 raw_ostream &write_hex(unsigned long long N);
208 raw_ostream &write(unsigned char C);
209 raw_ostream &write(const char *Ptr, size_t Size);
211 // Formatted output, see the format() function in Support/Format.h.
212 raw_ostream &operator<<(const format_object_base &Fmt);
214 /// Changes the foreground color of text that will be output from this point
216 /// @param colors ANSI color to use, the special SAVEDCOLOR can be used to
217 /// change only the bold attribute, and keep colors untouched
218 /// @param bold bold/brighter text, default false
219 /// @param bg if true change the background, default: change foreground
220 /// @returns itself so it can be used within << invocations
221 virtual raw_ostream &changeColor(enum Colors colors, bool bold=false,
222 bool bg=false) { return *this; }
224 /// Resets the colors to terminal defaults. Call this when you are done
225 /// outputting colored text, or before program exit.
226 virtual raw_ostream &resetColor() { return *this; }
228 //===--------------------------------------------------------------------===//
229 // Subclass Interface
230 //===--------------------------------------------------------------------===//
233 /// write_impl - The is the piece of the class that is implemented
234 /// by subclasses. This writes the \args Size bytes starting at
235 /// \arg Ptr to the underlying stream.
237 /// \invariant { Size > 0 }
238 virtual void write_impl(const char *Ptr, size_t Size) = 0;
240 // An out of line virtual method to provide a home for the class vtable.
241 virtual void handle();
243 /// current_pos - Return the current position within the stream, not
244 /// counting the bytes currently in the buffer.
245 virtual uint64_t current_pos() = 0;
248 /// error_detected - Set the flag indicating that an output error has
249 /// been encountered.
250 void error_detected() { Error = true; }
252 typedef char * iterator;
253 iterator begin() { return OutBufStart; }
254 iterator end() { return OutBufCur; }
256 //===--------------------------------------------------------------------===//
258 //===--------------------------------------------------------------------===//
260 /// flush_nonempty - Flush the current buffer, which is known to be
261 /// non-empty. This outputs the currently buffered data and resets
262 /// the buffer to empty.
263 void flush_nonempty();
266 //===----------------------------------------------------------------------===//
267 // File Output Streams
268 //===----------------------------------------------------------------------===//
270 /// raw_fd_ostream - A raw_ostream that writes to a file descriptor.
272 class raw_fd_ostream : public raw_ostream {
277 /// write_impl - See raw_ostream::write_impl.
278 virtual void write_impl(const char *Ptr, size_t Size);
280 /// current_pos - Return the current position within the stream, not
281 /// counting the bytes currently in the buffer.
282 virtual uint64_t current_pos() { return pos; }
285 /// raw_fd_ostream - Open the specified file for writing. If an
286 /// error occurs, information about the error is put into ErrorInfo,
287 /// and the stream should be immediately destroyed; the string will
288 /// be empty if no error occurred.
290 /// \param Filename - The file to open. If this is "-" then the
291 /// stream will use stdout instead.
292 /// \param Binary - The file should be opened in binary mode on
293 /// platforms that support this distinction.
294 /// \param Force - Don't consider the case where the file already
295 /// exists to be an error.
296 raw_fd_ostream(const char *Filename, bool Binary, bool Force,
297 std::string &ErrorInfo);
299 /// raw_fd_ostream ctor - FD is the file descriptor that this writes to. If
300 /// ShouldClose is true, this closes the file when the stream is destroyed.
301 raw_fd_ostream(int fd, bool shouldClose,
302 bool unbuffered=false) : raw_ostream(unbuffered), FD(fd),
303 ShouldClose(shouldClose) {}
307 /// close - Manually flush the stream and close the file.
310 /// tell - Return the current offset with the file.
311 uint64_t tell() { return pos + GetNumBytesInBuffer(); }
313 /// seek - Flushes the stream and repositions the underlying file descriptor
314 /// positition to the offset specified from the beginning of the file.
315 uint64_t seek(uint64_t off);
317 virtual raw_ostream &changeColor(enum Colors colors, bool bold=false,
319 virtual raw_ostream &resetColor();
322 /// raw_stdout_ostream - This is a stream that always prints to stdout.
324 class raw_stdout_ostream : public raw_fd_ostream {
325 // An out of line virtual method to provide a home for the class vtable.
326 virtual void handle();
328 raw_stdout_ostream();
331 /// raw_stderr_ostream - This is a stream that always prints to stderr.
333 class raw_stderr_ostream : public raw_fd_ostream {
334 // An out of line virtual method to provide a home for the class vtable.
335 virtual void handle();
337 raw_stderr_ostream();
340 /// outs() - This returns a reference to a raw_ostream for standard output.
341 /// Use it like: outs() << "foo" << "bar";
344 /// errs() - This returns a reference to a raw_ostream for standard error.
345 /// Use it like: errs() << "foo" << "bar";
348 /// nulls() - This returns a reference to a raw_ostream which simply discards
350 raw_ostream &nulls();
352 //===----------------------------------------------------------------------===//
353 // Output Stream Adaptors
354 //===----------------------------------------------------------------------===//
356 /// raw_os_ostream - A raw_ostream that writes to an std::ostream. This is a
357 /// simple adaptor class. It does not check for output errors; clients should
358 /// use the underlying stream to detect errors.
359 class raw_os_ostream : public raw_ostream {
362 /// write_impl - See raw_ostream::write_impl.
363 virtual void write_impl(const char *Ptr, size_t Size);
365 /// current_pos - Return the current position within the stream, not
366 /// counting the bytes currently in the buffer.
367 virtual uint64_t current_pos();
370 raw_os_ostream(std::ostream &O) : OS(O) {}
373 /// tell - Return the current offset with the stream.
377 /// raw_string_ostream - A raw_ostream that writes to an std::string. This is a
378 /// simple adaptor class. This class does not encounter output errors.
379 class raw_string_ostream : public raw_ostream {
382 /// write_impl - See raw_ostream::write_impl.
383 virtual void write_impl(const char *Ptr, size_t Size);
385 /// current_pos - Return the current position within the stream, not
386 /// counting the bytes currently in the buffer.
387 virtual uint64_t current_pos() { return OS.size(); }
389 explicit raw_string_ostream(std::string &O) : OS(O) {}
390 ~raw_string_ostream();
392 /// tell - Return the current offset with the stream.
393 uint64_t tell() { return OS.size() + GetNumBytesInBuffer(); }
395 /// str - Flushes the stream contents to the target string and returns
396 /// the string's reference.
403 /// raw_svector_ostream - A raw_ostream that writes to an SmallVector or
404 /// SmallString. This is a simple adaptor class. This class does not
405 /// encounter output errors.
406 class raw_svector_ostream : public raw_ostream {
407 SmallVectorImpl<char> &OS;
409 /// write_impl - See raw_ostream::write_impl.
410 virtual void write_impl(const char *Ptr, size_t Size);
412 /// current_pos - Return the current position within the stream, not
413 /// counting the bytes currently in the buffer.
414 virtual uint64_t current_pos();
416 explicit raw_svector_ostream(SmallVectorImpl<char> &O) : OS(O) {}
417 ~raw_svector_ostream();
419 /// tell - Return the current offset with the stream.
423 /// raw_null_ostream - A raw_ostream that discards all output.
424 class raw_null_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();
433 explicit raw_null_ostream() {}
437 } // end llvm namespace