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1 : //===--- raw_ostream.h - Raw output stream ----------------------*- C++ -*-===//
2 : //
3 : // The LLVM Compiler Infrastructure
4 : //
5 : // This file is distributed under the University of Illinois Open Source
6 : // License. See LICENSE.TXT for details.
7 : //
8 : //===----------------------------------------------------------------------===//
9 : //
10 : // This file defines the raw_ostream class.
11 : //
12 : //===----------------------------------------------------------------------===//
13 :
14 : #ifndef LLVM_SUPPORT_RAW_OSTREAM_H
15 : #define LLVM_SUPPORT_RAW_OSTREAM_H
16 :
17 : #include "llvm/ADT/SmallVector.h"
18 : #include "llvm/ADT/StringRef.h"
19 : #include <cassert>
20 : #include <cstddef>
21 : #include <cstdint>
22 : #include <cstring>
23 : #include <string>
24 : #include <system_error>
25 :
26 : namespace llvm {
27 :
28 : class formatv_object_base;
29 : class format_object_base;
30 : class FormattedString;
31 : class FormattedNumber;
32 : class FormattedBytes;
33 :
34 : namespace sys {
35 : namespace fs {
36 : enum FileAccess : unsigned;
37 : enum OpenFlags : unsigned;
38 : enum CreationDisposition : unsigned;
39 : } // end namespace fs
40 : } // end namespace sys
41 :
42 : /// This class implements an extremely fast bulk output stream that can *only*
43 : /// output to a stream. It does not support seeking, reopening, rewinding, line
44 : /// buffered disciplines etc. It is a simple buffer that outputs
45 : /// a chunk at a time.
46 : class raw_ostream {
47 : private:
48 : /// The buffer is handled in such a way that the buffer is
49 : /// uninitialized, unbuffered, or out of space when OutBufCur >=
50 : /// OutBufEnd. Thus a single comparison suffices to determine if we
51 : /// need to take the slow path to write a single character.
52 : ///
53 : /// The buffer is in one of three states:
54 : /// 1. Unbuffered (BufferMode == Unbuffered)
55 : /// 1. Uninitialized (BufferMode != Unbuffered && OutBufStart == 0).
56 : /// 2. Buffered (BufferMode != Unbuffered && OutBufStart != 0 &&
57 : /// OutBufEnd - OutBufStart >= 1).
58 : ///
59 : /// If buffered, then the raw_ostream owns the buffer if (BufferMode ==
60 : /// InternalBuffer); otherwise the buffer has been set via SetBuffer and is
61 : /// managed by the subclass.
62 : ///
63 : /// If a subclass installs an external buffer using SetBuffer then it can wait
64 : /// for a \see write_impl() call to handle the data which has been put into
65 : /// this buffer.
66 : char *OutBufStart, *OutBufEnd, *OutBufCur;
67 :
68 : enum BufferKind {
69 : Unbuffered = 0,
70 : InternalBuffer,
71 : ExternalBuffer
72 : } BufferMode;
73 :
74 : public:
75 : // color order matches ANSI escape sequence, don't change
76 : enum Colors {
77 : BLACK = 0,
78 : RED,
79 : GREEN,
80 : YELLOW,
81 : BLUE,
82 : MAGENTA,
83 : CYAN,
84 : WHITE,
85 : SAVEDCOLOR
86 : };
87 :
88 : explicit raw_ostream(bool unbuffered = false)
89 103376657 : : BufferMode(unbuffered ? Unbuffered : InternalBuffer) {
90 : // Start out ready to flush.
91 102498226 : OutBufStart = OutBufEnd = OutBufCur = nullptr;
92 : }
93 :
94 : raw_ostream(const raw_ostream &) = delete;
95 : void operator=(const raw_ostream &) = delete;
96 :
97 : virtual ~raw_ostream();
98 :
99 : /// tell - Return the current offset with the file.
100 19233808 : uint64_t tell() const { return current_pos() + GetNumBytesInBuffer(); }
101 :
102 : //===--------------------------------------------------------------------===//
103 : // Configuration Interface
104 : //===--------------------------------------------------------------------===//
105 :
106 : /// Set the stream to be buffered, with an automatically determined buffer
107 : /// size.
108 : void SetBuffered();
109 :
110 : /// Set the stream to be buffered, using the specified buffer size.
111 18122851 : void SetBufferSize(size_t Size) {
112 : flush();
113 18122851 : SetBufferAndMode(new char[Size], Size, InternalBuffer);
114 18122851 : }
115 :
116 : size_t GetBufferSize() const {
117 : // If we're supposed to be buffered but haven't actually gotten around
118 : // to allocating the buffer yet, return the value that would be used.
119 174202 : if (BufferMode != Unbuffered && OutBufStart == nullptr)
120 41654 : return preferred_buffer_size();
121 :
122 : // Otherwise just return the size of the allocated buffer.
123 132548 : return OutBufEnd - OutBufStart;
124 : }
125 :
126 : /// Set the stream to be unbuffered. When unbuffered, the stream will flush
127 : /// after every write. This routine will also flush the buffer immediately
128 : /// when the stream is being set to unbuffered.
129 113317769 : void SetUnbuffered() {
130 : flush();
131 113317769 : SetBufferAndMode(nullptr, 0, Unbuffered);
132 113317891 : }
133 :
134 0 : size_t GetNumBytesInBuffer() const {
135 15994567 : return OutBufCur - OutBufStart;
136 : }
137 :
138 : //===--------------------------------------------------------------------===//
139 : // Data Output Interface
140 : //===--------------------------------------------------------------------===//
141 :
142 : void flush() {
143 149636617 : if (OutBufCur != OutBufStart)
144 13303169 : flush_nonempty();
145 : }
146 :
147 : raw_ostream &operator<<(char C) {
148 549568854 : if (OutBufCur >= OutBufEnd)
149 352901457 : return write(C);
150 196667398 : *OutBufCur++ = C;
151 : return *this;
152 : }
153 :
154 : raw_ostream &operator<<(unsigned char C) {
155 13516232 : if (OutBufCur >= OutBufEnd)
156 2959711 : return write(C);
157 10556521 : *OutBufCur++ = C;
158 : return *this;
159 : }
160 :
161 : raw_ostream &operator<<(signed char C) {
162 124 : if (OutBufCur >= OutBufEnd)
163 0 : return write(C);
164 124 : *OutBufCur++ = C;
165 : return *this;
166 : }
167 :
168 652558881 : raw_ostream &operator<<(StringRef Str) {
169 : // Inline fast path, particularly for strings with a known length.
170 : size_t Size = Str.size();
171 :
172 : // Make sure we can use the fast path.
173 652558881 : if (Size > (size_t)(OutBufEnd - OutBufCur))
174 332276502 : return write(Str.data(), Size);
175 :
176 320282379 : if (Size) {
177 296249407 : memcpy(OutBufCur, Str.data(), Size);
178 296249407 : OutBufCur += Size;
179 : }
180 : return *this;
181 : }
182 :
183 380653173 : raw_ostream &operator<<(const char *Str) {
184 : // Inline fast path, particularly for constant strings where a sufficiently
185 : // smart compiler will simplify strlen.
186 :
187 380653173 : return this->operator<<(StringRef(Str));
188 : }
189 :
190 : raw_ostream &operator<<(const std::string &Str) {
191 : // Avoid the fast path, it would only increase code size for a marginal win.
192 123501797 : return write(Str.data(), Str.length());
193 : }
194 :
195 : raw_ostream &operator<<(const SmallVectorImpl<char> &Str) {
196 63432144 : return write(Str.data(), Str.size());
197 : }
198 :
199 : raw_ostream &operator<<(unsigned long N);
200 : raw_ostream &operator<<(long N);
201 : raw_ostream &operator<<(unsigned long long N);
202 : raw_ostream &operator<<(long long N);
203 : raw_ostream &operator<<(const void *P);
204 :
205 : raw_ostream &operator<<(unsigned int N) {
206 35804992 : return this->operator<<(static_cast<unsigned long>(N));
207 : }
208 :
209 : raw_ostream &operator<<(int N) {
210 12031600 : return this->operator<<(static_cast<long>(N));
211 : }
212 :
213 : raw_ostream &operator<<(double N);
214 :
215 : /// Output \p N in hexadecimal, without any prefix or padding.
216 : raw_ostream &write_hex(unsigned long long N);
217 :
218 : /// Output a formatted UUID with dash separators.
219 : using uuid_t = uint8_t[16];
220 : raw_ostream &write_uuid(const uuid_t UUID);
221 :
222 : /// Output \p Str, turning '\\', '\t', '\n', '"', and anything that doesn't
223 : /// satisfy llvm::isPrint into an escape sequence.
224 : raw_ostream &write_escaped(StringRef Str, bool UseHexEscapes = false);
225 :
226 : raw_ostream &write(unsigned char C);
227 : raw_ostream &write(const char *Ptr, size_t Size);
228 :
229 : // Formatted output, see the format() function in Support/Format.h.
230 : raw_ostream &operator<<(const format_object_base &Fmt);
231 :
232 : // Formatted output, see the leftJustify() function in Support/Format.h.
233 : raw_ostream &operator<<(const FormattedString &);
234 :
235 : // Formatted output, see the formatHex() function in Support/Format.h.
236 : raw_ostream &operator<<(const FormattedNumber &);
237 :
238 : // Formatted output, see the formatv() function in Support/FormatVariadic.h.
239 : raw_ostream &operator<<(const formatv_object_base &);
240 :
241 : // Formatted output, see the format_bytes() function in Support/Format.h.
242 : raw_ostream &operator<<(const FormattedBytes &);
243 :
244 : /// indent - Insert 'NumSpaces' spaces.
245 : raw_ostream &indent(unsigned NumSpaces);
246 :
247 : /// write_zeros - Insert 'NumZeros' nulls.
248 : raw_ostream &write_zeros(unsigned NumZeros);
249 :
250 : /// Changes the foreground color of text that will be output from this point
251 : /// forward.
252 : /// @param Color ANSI color to use, the special SAVEDCOLOR can be used to
253 : /// change only the bold attribute, and keep colors untouched
254 : /// @param Bold bold/brighter text, default false
255 : /// @param BG if true change the background, default: change foreground
256 : /// @returns itself so it can be used within << invocations
257 0 : virtual raw_ostream &changeColor(enum Colors Color,
258 : bool Bold = false,
259 : bool BG = false) {
260 : (void)Color;
261 : (void)Bold;
262 : (void)BG;
263 0 : return *this;
264 : }
265 :
266 : /// Resets the colors to terminal defaults. Call this when you are done
267 : /// outputting colored text, or before program exit.
268 0 : virtual raw_ostream &resetColor() { return *this; }
269 :
270 : /// Reverses the foreground and background colors.
271 0 : virtual raw_ostream &reverseColor() { return *this; }
272 :
273 : /// This function determines if this stream is connected to a "tty" or
274 : /// "console" window. That is, the output would be displayed to the user
275 : /// rather than being put on a pipe or stored in a file.
276 430 : virtual bool is_displayed() const { return false; }
277 :
278 : /// This function determines if this stream is displayed and supports colors.
279 2586 : virtual bool has_colors() const { return is_displayed(); }
280 :
281 : //===--------------------------------------------------------------------===//
282 : // Subclass Interface
283 : //===--------------------------------------------------------------------===//
284 :
285 : private:
286 : /// The is the piece of the class that is implemented by subclasses. This
287 : /// writes the \p Size bytes starting at
288 : /// \p Ptr to the underlying stream.
289 : ///
290 : /// This function is guaranteed to only be called at a point at which it is
291 : /// safe for the subclass to install a new buffer via SetBuffer.
292 : ///
293 : /// \param Ptr The start of the data to be written. For buffered streams this
294 : /// is guaranteed to be the start of the buffer.
295 : ///
296 : /// \param Size The number of bytes to be written.
297 : ///
298 : /// \invariant { Size > 0 }
299 : virtual void write_impl(const char *Ptr, size_t Size) = 0;
300 :
301 : /// Return the current position within the stream, not counting the bytes
302 : /// currently in the buffer.
303 : virtual uint64_t current_pos() const = 0;
304 :
305 : protected:
306 : /// Use the provided buffer as the raw_ostream buffer. This is intended for
307 : /// use only by subclasses which can arrange for the output to go directly
308 : /// into the desired output buffer, instead of being copied on each flush.
309 : void SetBuffer(char *BufferStart, size_t Size) {
310 : SetBufferAndMode(BufferStart, Size, ExternalBuffer);
311 : }
312 :
313 : /// Return an efficient buffer size for the underlying output mechanism.
314 : virtual size_t preferred_buffer_size() const;
315 :
316 : /// Return the beginning of the current stream buffer, or 0 if the stream is
317 : /// unbuffered.
318 0 : const char *getBufferStart() const { return OutBufStart; }
319 :
320 : //===--------------------------------------------------------------------===//
321 : // Private Interface
322 : //===--------------------------------------------------------------------===//
323 : private:
324 : /// Install the given buffer and mode.
325 : void SetBufferAndMode(char *BufferStart, size_t Size, BufferKind Mode);
326 :
327 : /// Flush the current buffer, which is known to be non-empty. This outputs the
328 : /// currently buffered data and resets the buffer to empty.
329 : void flush_nonempty();
330 :
331 : /// Copy data into the buffer. Size must not be greater than the number of
332 : /// unused bytes in the buffer.
333 : void copy_to_buffer(const char *Ptr, size_t Size);
334 :
335 : virtual void anchor();
336 : };
337 :
338 : /// An abstract base class for streams implementations that also support a
339 : /// pwrite operation. This is useful for code that can mostly stream out data,
340 : /// but needs to patch in a header that needs to know the output size.
341 119016375 : class raw_pwrite_stream : public raw_ostream {
342 : virtual void pwrite_impl(const char *Ptr, size_t Size, uint64_t Offset) = 0;
343 : void anchor() override;
344 :
345 : public:
346 : explicit raw_pwrite_stream(bool Unbuffered = false)
347 : : raw_ostream(Unbuffered) {}
348 : void pwrite(const char *Ptr, size_t Size, uint64_t Offset) {
349 : #ifndef NDBEBUG
350 23019 : uint64_t Pos = tell();
351 : // /dev/null always reports a pos of 0, so we cannot perform this check
352 : // in that case.
353 : if (Pos)
354 : assert(Size + Offset <= Pos && "We don't support extending the stream");
355 : #endif
356 23022 : pwrite_impl(Ptr, Size, Offset);
357 : }
358 : };
359 :
360 : //===----------------------------------------------------------------------===//
361 : // File Output Streams
362 : //===----------------------------------------------------------------------===//
363 :
364 : /// A raw_ostream that writes to a file descriptor.
365 : ///
366 : class raw_fd_ostream : public raw_pwrite_stream {
367 : int FD;
368 : bool ShouldClose;
369 :
370 : bool SupportsSeeking;
371 :
372 : #ifdef _WIN32
373 : /// True if this fd refers to a Windows console device. Mintty and other
374 : /// terminal emulators are TTYs, but they are not consoles.
375 : bool IsWindowsConsole = false;
376 : #endif
377 :
378 : std::error_code EC;
379 :
380 : uint64_t pos;
381 :
382 : /// See raw_ostream::write_impl.
383 : void write_impl(const char *Ptr, size_t Size) override;
384 :
385 : void pwrite_impl(const char *Ptr, size_t Size, uint64_t Offset) override;
386 :
387 : /// Return the current position within the stream, not counting the bytes
388 : /// currently in the buffer.
389 10030375 : uint64_t current_pos() const override { return pos; }
390 :
391 : /// Determine an efficient buffer size.
392 : size_t preferred_buffer_size() const override;
393 :
394 : /// Set the flag indicating that an output error has been encountered.
395 10 : void error_detected(std::error_code EC) { this->EC = EC; }
396 :
397 : void anchor() override;
398 :
399 : public:
400 : /// Open the specified file for writing. If an error occurs, information
401 : /// about the error is put into EC, and the stream should be immediately
402 : /// destroyed;
403 : /// \p Flags allows optional flags to control how the file will be opened.
404 : ///
405 : /// As a special case, if Filename is "-", then the stream will use
406 : /// STDOUT_FILENO instead of opening a file. This will not close the stdout
407 : /// descriptor.
408 : raw_fd_ostream(StringRef Filename, std::error_code &EC);
409 : raw_fd_ostream(StringRef Filename, std::error_code &EC,
410 : sys::fs::CreationDisposition Disp);
411 : raw_fd_ostream(StringRef Filename, std::error_code &EC,
412 : sys::fs::FileAccess Access);
413 : raw_fd_ostream(StringRef Filename, std::error_code &EC,
414 : sys::fs::OpenFlags Flags);
415 : raw_fd_ostream(StringRef Filename, std::error_code &EC,
416 : sys::fs::CreationDisposition Disp, sys::fs::FileAccess Access,
417 : sys::fs::OpenFlags Flags);
418 :
419 : /// FD is the file descriptor that this writes to. If ShouldClose is true,
420 : /// this closes the file when the stream is destroyed. If FD is for stdout or
421 : /// stderr, it will not be closed.
422 : raw_fd_ostream(int fd, bool shouldClose, bool unbuffered=false);
423 :
424 : ~raw_fd_ostream() override;
425 :
426 : /// Manually flush the stream and close the file. Note that this does not call
427 : /// fsync.
428 : void close();
429 :
430 0 : bool supportsSeeking() { return SupportsSeeking; }
431 :
432 : /// Flushes the stream and repositions the underlying file descriptor position
433 : /// to the offset specified from the beginning of the file.
434 : uint64_t seek(uint64_t off);
435 :
436 : raw_ostream &changeColor(enum Colors colors, bool bold=false,
437 : bool bg=false) override;
438 : raw_ostream &resetColor() override;
439 :
440 : raw_ostream &reverseColor() override;
441 :
442 : bool is_displayed() const override;
443 :
444 : bool has_colors() const override;
445 :
446 0 : std::error_code error() const { return EC; }
447 :
448 : /// Return the value of the flag in this raw_fd_ostream indicating whether an
449 : /// output error has been encountered.
450 : /// This doesn't implicitly flush any pending output. Also, it doesn't
451 : /// guarantee to detect all errors unless the stream has been closed.
452 260154 : bool has_error() const { return bool(EC); }
453 :
454 : /// Set the flag read by has_error() to false. If the error flag is set at the
455 : /// time when this raw_ostream's destructor is called, report_fatal_error is
456 : /// called to report the error. Use clear_error() after handling the error to
457 : /// avoid this behavior.
458 : ///
459 : /// "Errors should never pass silently.
460 : /// Unless explicitly silenced."
461 : /// - from The Zen of Python, by Tim Peters
462 : ///
463 10 : void clear_error() { EC = std::error_code(); }
464 : };
465 :
466 : /// This returns a reference to a raw_ostream for standard output. Use it like:
467 : /// outs() << "foo" << "bar";
468 : raw_ostream &outs();
469 :
470 : /// This returns a reference to a raw_ostream for standard error. Use it like:
471 : /// errs() << "foo" << "bar";
472 : raw_ostream &errs();
473 :
474 : /// This returns a reference to a raw_ostream which simply discards output.
475 : raw_ostream &nulls();
476 :
477 : //===----------------------------------------------------------------------===//
478 : // Output Stream Adaptors
479 : //===----------------------------------------------------------------------===//
480 :
481 : /// A raw_ostream that writes to an std::string. This is a simple adaptor
482 : /// class. This class does not encounter output errors.
483 : class raw_string_ostream : public raw_ostream {
484 : std::string &OS;
485 :
486 : /// See raw_ostream::write_impl.
487 : void write_impl(const char *Ptr, size_t Size) override;
488 :
489 : /// Return the current position within the stream, not counting the bytes
490 : /// currently in the buffer.
491 24775 : uint64_t current_pos() const override { return OS.size(); }
492 :
493 : public:
494 5659031 : explicit raw_string_ostream(std::string &O) : OS(O) {}
495 : ~raw_string_ostream() override;
496 :
497 : /// Flushes the stream contents to the target string and returns the string's
498 : /// reference.
499 : std::string& str() {
500 465 : flush();
501 3954637 : return OS;
502 : }
503 : };
504 :
505 : /// A raw_ostream that writes to an SmallVector or SmallString. This is a
506 : /// simple adaptor class. This class does not encounter output errors.
507 : /// raw_svector_ostream operates without a buffer, delegating all memory
508 : /// management to the SmallString. Thus the SmallString is always up-to-date,
509 : /// may be used directly and there is no need to call flush().
510 : class raw_svector_ostream : public raw_pwrite_stream {
511 : SmallVectorImpl<char> &OS;
512 :
513 : /// See raw_ostream::write_impl.
514 : void write_impl(const char *Ptr, size_t Size) override;
515 :
516 : void pwrite_impl(const char *Ptr, size_t Size, uint64_t Offset) override;
517 :
518 : /// Return the current position within the stream.
519 : uint64_t current_pos() const override;
520 :
521 : public:
522 : /// Construct a new raw_svector_ostream.
523 : ///
524 : /// \param O The vector to write to; this should generally have at least 128
525 : /// bytes free to avoid any extraneous memory overhead.
526 226381400 : explicit raw_svector_ostream(SmallVectorImpl<char> &O) : OS(O) {
527 113186638 : SetUnbuffered();
528 : }
529 :
530 72093662 : ~raw_svector_ostream() override = default;
531 :
532 : void flush() = delete;
533 :
534 : /// Return a StringRef for the vector contents.
535 45368896 : StringRef str() { return StringRef(OS.data(), OS.size()); }
536 : };
537 :
538 : /// A raw_ostream that discards all output.
539 : class raw_null_ostream : public raw_pwrite_stream {
540 : /// See raw_ostream::write_impl.
541 : void write_impl(const char *Ptr, size_t size) override;
542 : void pwrite_impl(const char *Ptr, size_t Size, uint64_t Offset) override;
543 :
544 : /// Return the current position within the stream, not counting the bytes
545 : /// currently in the buffer.
546 : uint64_t current_pos() const override;
547 :
548 : public:
549 5597843 : explicit raw_null_ostream() = default;
550 : ~raw_null_ostream() override;
551 : };
552 :
553 : class buffer_ostream : public raw_svector_ostream {
554 : raw_ostream &OS;
555 : SmallVector<char, 0> Buffer;
556 :
557 : public:
558 3157 : buffer_ostream(raw_ostream &OS) : raw_svector_ostream(Buffer), OS(OS) {}
559 9404 : ~buffer_ostream() override { OS << str(); }
560 : };
561 :
562 : } // end namespace llvm
563 :
564 : #endif // LLVM_SUPPORT_RAW_OSTREAM_H
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