LCOV - code coverage report
Current view: top level - include/llvm/Support - raw_ostream.h (source / functions) Hit Total Coverage
Test: llvm-toolchain.info Lines: 58 63 92.1 %
Date: 2017-09-14 15:23:50 Functions: 11 15 73.3 %
Legend: Lines: hit not hit

          Line data    Source code
       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 OpenFlags : unsigned;
      37             : } // end namespace fs
      38             : } // end namespace sys
      39             : 
      40             : /// This class implements an extremely fast bulk output stream that can *only*
      41             : /// output to a stream.  It does not support seeking, reopening, rewinding, line
      42             : /// buffered disciplines etc. It is a simple buffer that outputs
      43             : /// a chunk at a time.
      44             : class raw_ostream {
      45             : private:
      46             :   /// The buffer is handled in such a way that the buffer is
      47             :   /// uninitialized, unbuffered, or out of space when OutBufCur >=
      48             :   /// OutBufEnd. Thus a single comparison suffices to determine if we
      49             :   /// need to take the slow path to write a single character.
      50             :   ///
      51             :   /// The buffer is in one of three states:
      52             :   ///  1. Unbuffered (BufferMode == Unbuffered)
      53             :   ///  1. Uninitialized (BufferMode != Unbuffered && OutBufStart == 0).
      54             :   ///  2. Buffered (BufferMode != Unbuffered && OutBufStart != 0 &&
      55             :   ///               OutBufEnd - OutBufStart >= 1).
      56             :   ///
      57             :   /// If buffered, then the raw_ostream owns the buffer if (BufferMode ==
      58             :   /// InternalBuffer); otherwise the buffer has been set via SetBuffer and is
      59             :   /// managed by the subclass.
      60             :   ///
      61             :   /// If a subclass installs an external buffer using SetBuffer then it can wait
      62             :   /// for a \see write_impl() call to handle the data which has been put into
      63             :   /// this buffer.
      64             :   char *OutBufStart, *OutBufEnd, *OutBufCur;
      65             : 
      66             :   enum BufferKind {
      67             :     Unbuffered = 0,
      68             :     InternalBuffer,
      69             :     ExternalBuffer
      70             :   } BufferMode;
      71             : 
      72             : public:
      73             :   // color order matches ANSI escape sequence, don't change
      74             :   enum Colors {
      75             :     BLACK = 0,
      76             :     RED,
      77             :     GREEN,
      78             :     YELLOW,
      79             :     BLUE,
      80             :     MAGENTA,
      81             :     CYAN,
      82             :     WHITE,
      83             :     SAVEDCOLOR
      84             :   };
      85             : 
      86             :   explicit raw_ostream(bool unbuffered = false)
      87    19423691 :       : BufferMode(unbuffered ? Unbuffered : InternalBuffer) {
      88             :     // Start out ready to flush.
      89    19423691 :     OutBufStart = OutBufEnd = OutBufCur = nullptr;
      90             :   }
      91             : 
      92             :   raw_ostream(const raw_ostream &) = delete;
      93             :   void operator=(const raw_ostream &) = delete;
      94             : 
      95             :   virtual ~raw_ostream();
      96             : 
      97             :   /// tell - Return the current offset with the file.
      98    11992625 :   uint64_t tell() const { return current_pos() + GetNumBytesInBuffer(); }
      99             : 
     100             :   //===--------------------------------------------------------------------===//
     101             :   // Configuration Interface
     102             :   //===--------------------------------------------------------------------===//
     103             : 
     104             :   /// Set the stream to be buffered, with an automatically determined buffer
     105             :   /// size.
     106             :   void SetBuffered();
     107             : 
     108             :   /// Set the stream to be buffered, using the specified buffer size.
     109     1872641 :   void SetBufferSize(size_t Size) {
     110     1872641 :     flush();
     111     1872641 :     SetBufferAndMode(new char[Size], Size, InternalBuffer);
     112     1872641 :   }
     113             : 
     114             :   size_t GetBufferSize() const {
     115             :     // If we're supposed to be buffered but haven't actually gotten around
     116             :     // to allocating the buffer yet, return the value that would be used.
     117     1813792 :     if (BufferMode != Unbuffered && OutBufStart == nullptr)
     118       30278 :       return preferred_buffer_size();
     119             : 
     120             :     // Otherwise just return the size of the allocated buffer.
     121     1783514 :     return OutBufEnd - OutBufStart;
     122             :   }
     123             : 
     124             :   /// Set the stream to be unbuffered. When unbuffered, the stream will flush
     125             :   /// after every write. This routine will also flush the buffer immediately
     126             :   /// when the stream is being set to unbuffered.
     127    16829624 :   void SetUnbuffered() {
     128    16829624 :     flush();
     129    16829624 :     SetBufferAndMode(nullptr, 0, Unbuffered);
     130    16829622 :   }
     131             : 
     132             :   size_t GetNumBytesInBuffer() const {
     133    23332248 :     return OutBufCur - OutBufStart;
     134             :   }
     135             : 
     136             :   //===--------------------------------------------------------------------===//
     137             :   // Data Output Interface
     138             :   //===--------------------------------------------------------------------===//
     139             : 
     140             :   void flush() {
     141    25544875 :     if (OutBufCur != OutBufStart)
     142     2170787 :       flush_nonempty();
     143             :   }
     144             : 
     145             :   raw_ostream &operator<<(char C) {
     146   149436591 :     if (OutBufCur >= OutBufEnd)
     147    53167116 :       return write(C);
     148    96269991 :     *OutBufCur++ = C;
     149             :     return *this;
     150             :   }
     151             : 
     152             :   raw_ostream &operator<<(unsigned char C) {
     153     7162414 :     if (OutBufCur >= OutBufEnd)
     154      678032 :       return write(C);
     155     6484382 :     *OutBufCur++ = C;
     156             :     return *this;
     157             :   }
     158             : 
     159             :   raw_ostream &operator<<(signed char C) {
     160         131 :     if (OutBufCur >= OutBufEnd)
     161           0 :       return write(C);
     162         131 :     *OutBufCur++ = C;
     163             :     return *this;
     164             :   }
     165             : 
     166   253221193 :   raw_ostream &operator<<(StringRef Str) {
     167             :     // Inline fast path, particularly for strings with a known length.
     168   253221193 :     size_t Size = Str.size();
     169             : 
     170             :     // Make sure we can use the fast path.
     171   253221193 :     if (Size > (size_t)(OutBufEnd - OutBufCur))
     172   113630576 :       return write(Str.data(), Size);
     173             : 
     174   139590617 :     if (Size) {
     175   130394702 :       memcpy(OutBufCur, Str.data(), Size);
     176   130394702 :       OutBufCur += Size;
     177             :     }
     178             :     return *this;
     179             :   }
     180             : 
     181   164979146 :   raw_ostream &operator<<(const char *Str) {
     182             :     // Inline fast path, particularly for constant strings where a sufficiently
     183             :     // smart compiler will simplify strlen.
     184             : 
     185   164979146 :     return this->operator<<(StringRef(Str));
     186             :   }
     187             : 
     188             :   raw_ostream &operator<<(const std::string &Str) {
     189             :     // Avoid the fast path, it would only increase code size for a marginal win.
     190    46384358 :     return write(Str.data(), Str.length());
     191             :   }
     192             : 
     193             :   raw_ostream &operator<<(const SmallVectorImpl<char> &Str) {
     194     4656534 :     return write(Str.data(), Str.size());
     195             :   }
     196             : 
     197             :   raw_ostream &operator<<(unsigned long N);
     198             :   raw_ostream &operator<<(long N);
     199             :   raw_ostream &operator<<(unsigned long long N);
     200             :   raw_ostream &operator<<(long long N);
     201             :   raw_ostream &operator<<(const void *P);
     202             : 
     203             :   raw_ostream &operator<<(unsigned int N) {
     204    30520882 :     return this->operator<<(static_cast<unsigned long>(N));
     205             :   }
     206             : 
     207             :   raw_ostream &operator<<(int N) {
     208     5346468 :     return this->operator<<(static_cast<long>(N));
     209             :   }
     210             : 
     211             :   raw_ostream &operator<<(double N);
     212             : 
     213             :   /// Output \p N in hexadecimal, without any prefix or padding.
     214             :   raw_ostream &write_hex(unsigned long long N);
     215             : 
     216             :   /// Output a formatted UUID with dash separators.
     217             :   using uuid_t = uint8_t[16];
     218             :   raw_ostream &write_uuid(const uuid_t UUID);
     219             : 
     220             :   /// Output \p Str, turning '\\', '\t', '\n', '"', and anything that doesn't
     221             :   /// satisfy std::isprint into an escape sequence.
     222             :   raw_ostream &write_escaped(StringRef Str, bool UseHexEscapes = false);
     223             : 
     224             :   raw_ostream &write(unsigned char C);
     225             :   raw_ostream &write(const char *Ptr, size_t Size);
     226             : 
     227             :   // Formatted output, see the format() function in Support/Format.h.
     228             :   raw_ostream &operator<<(const format_object_base &Fmt);
     229             : 
     230             :   // Formatted output, see the leftJustify() function in Support/Format.h.
     231             :   raw_ostream &operator<<(const FormattedString &);
     232             : 
     233             :   // Formatted output, see the formatHex() function in Support/Format.h.
     234             :   raw_ostream &operator<<(const FormattedNumber &);
     235             : 
     236             :   // Formatted output, see the formatv() function in Support/FormatVariadic.h.
     237             :   raw_ostream &operator<<(const formatv_object_base &);
     238             : 
     239             :   // Formatted output, see the format_bytes() function in Support/Format.h.
     240             :   raw_ostream &operator<<(const FormattedBytes &);
     241             : 
     242             :   /// indent - Insert 'NumSpaces' spaces.
     243             :   raw_ostream &indent(unsigned NumSpaces);
     244             : 
     245             :   /// Changes the foreground color of text that will be output from this point
     246             :   /// forward.
     247             :   /// @param Color ANSI color to use, the special SAVEDCOLOR can be used to
     248             :   /// change only the bold attribute, and keep colors untouched
     249             :   /// @param Bold bold/brighter text, default false
     250             :   /// @param BG if true change the background, default: change foreground
     251             :   /// @returns itself so it can be used within << invocations
     252           0 :   virtual raw_ostream &changeColor(enum Colors Color,
     253             :                                    bool Bold = false,
     254             :                                    bool BG = false) {
     255             :     (void)Color;
     256             :     (void)Bold;
     257             :     (void)BG;
     258           0 :     return *this;
     259             :   }
     260             : 
     261             :   /// Resets the colors to terminal defaults. Call this when you are done
     262             :   /// outputting colored text, or before program exit.
     263           0 :   virtual raw_ostream &resetColor() { return *this; }
     264             : 
     265             :   /// Reverses the foreground and background colors.
     266           0 :   virtual raw_ostream &reverseColor() { return *this; }
     267             : 
     268             :   /// This function determines if this stream is connected to a "tty" or
     269             :   /// "console" window. That is, the output would be displayed to the user
     270             :   /// rather than being put on a pipe or stored in a file.
     271         141 :   virtual bool is_displayed() const { return false; }
     272             : 
     273             :   /// This function determines if this stream is displayed and supports colors.
     274         141 :   virtual bool has_colors() const { return is_displayed(); }
     275             : 
     276             :   //===--------------------------------------------------------------------===//
     277             :   // Subclass Interface
     278             :   //===--------------------------------------------------------------------===//
     279             : 
     280             : private:
     281             :   /// The is the piece of the class that is implemented by subclasses.  This
     282             :   /// writes the \p Size bytes starting at
     283             :   /// \p Ptr to the underlying stream.
     284             :   ///
     285             :   /// This function is guaranteed to only be called at a point at which it is
     286             :   /// safe for the subclass to install a new buffer via SetBuffer.
     287             :   ///
     288             :   /// \param Ptr The start of the data to be written. For buffered streams this
     289             :   /// is guaranteed to be the start of the buffer.
     290             :   ///
     291             :   /// \param Size The number of bytes to be written.
     292             :   ///
     293             :   /// \invariant { Size > 0 }
     294             :   virtual void write_impl(const char *Ptr, size_t Size) = 0;
     295             : 
     296             :   // An out of line virtual method to provide a home for the class vtable.
     297             :   virtual void handle();
     298             : 
     299             :   /// Return the current position within the stream, not counting the bytes
     300             :   /// currently in the buffer.
     301             :   virtual uint64_t current_pos() const = 0;
     302             : 
     303             : protected:
     304             :   /// Use the provided buffer as the raw_ostream buffer. This is intended for
     305             :   /// use only by subclasses which can arrange for the output to go directly
     306             :   /// into the desired output buffer, instead of being copied on each flush.
     307             :   void SetBuffer(char *BufferStart, size_t Size) {
     308             :     SetBufferAndMode(BufferStart, Size, ExternalBuffer);
     309             :   }
     310             : 
     311             :   /// Return an efficient buffer size for the underlying output mechanism.
     312             :   virtual size_t preferred_buffer_size() const;
     313             : 
     314             :   /// Return the beginning of the current stream buffer, or 0 if the stream is
     315             :   /// unbuffered.
     316             :   const char *getBufferStart() const { return OutBufStart; }
     317             : 
     318             :   //===--------------------------------------------------------------------===//
     319             :   // Private Interface
     320             :   //===--------------------------------------------------------------------===//
     321             : private:
     322             :   /// Install the given buffer and mode.
     323             :   void SetBufferAndMode(char *BufferStart, size_t Size, BufferKind Mode);
     324             : 
     325             :   /// Flush the current buffer, which is known to be non-empty. This outputs the
     326             :   /// currently buffered data and resets the buffer to empty.
     327             :   void flush_nonempty();
     328             : 
     329             :   /// Copy data into the buffer. Size must not be greater than the number of
     330             :   /// unused bytes in the buffer.
     331             :   void copy_to_buffer(const char *Ptr, size_t Size);
     332             : };
     333             : 
     334             : /// An abstract base class for streams implementations that also support a
     335             : /// pwrite operation. This is useful for code that can mostly stream out data,
     336             : /// but needs to patch in a header that needs to know the output size.
     337    14640708 : class raw_pwrite_stream : public raw_ostream {
     338             :   virtual void pwrite_impl(const char *Ptr, size_t Size, uint64_t Offset) = 0;
     339             : 
     340             : public:
     341             :   explicit raw_pwrite_stream(bool Unbuffered = false)
     342    29282142 :       : raw_ostream(Unbuffered) {}
     343             :   void pwrite(const char *Ptr, size_t Size, uint64_t Offset) {
     344             : #ifndef NDBEBUG
     345       13202 :     uint64_t Pos = tell();
     346             :     // /dev/null always reports a pos of 0, so we cannot perform this check
     347             :     // in that case.
     348             :     if (Pos)
     349             :       assert(Size + Offset <= Pos && "We don't support extending the stream");
     350             : #endif
     351        6601 :     pwrite_impl(Ptr, Size, Offset);
     352             :   }
     353             : };
     354             : 
     355             : //===----------------------------------------------------------------------===//
     356             : // File Output Streams
     357             : //===----------------------------------------------------------------------===//
     358             : 
     359             : /// A raw_ostream that writes to a file descriptor.
     360             : ///
     361             : class raw_fd_ostream : public raw_pwrite_stream {
     362             :   int FD;
     363             :   bool ShouldClose;
     364             : 
     365             :   /// Error This flag is true if an error of any kind has been detected.
     366             :   ///
     367             :   bool Error;
     368             : 
     369             :   uint64_t pos;
     370             : 
     371             :   bool SupportsSeeking;
     372             : 
     373             :   /// See raw_ostream::write_impl.
     374             :   void write_impl(const char *Ptr, size_t Size) override;
     375             : 
     376             :   void pwrite_impl(const char *Ptr, size_t Size, uint64_t Offset) override;
     377             : 
     378             :   /// Return the current position within the stream, not counting the bytes
     379             :   /// currently in the buffer.
     380     2284823 :   uint64_t current_pos() const override { return pos; }
     381             : 
     382             :   /// Determine an efficient buffer size.
     383             :   size_t preferred_buffer_size() const override;
     384             : 
     385             :   /// Set the flag indicating that an output error has been encountered.
     386       16333 :   void error_detected() { Error = true; }
     387             : 
     388             : public:
     389             :   /// Open the specified file for writing. If an error occurs, information
     390             :   /// about the error is put into EC, and the stream should be immediately
     391             :   /// destroyed;
     392             :   /// \p Flags allows optional flags to control how the file will be opened.
     393             :   ///
     394             :   /// As a special case, if Filename is "-", then the stream will use
     395             :   /// STDOUT_FILENO instead of opening a file. This will not close the stdout
     396             :   /// descriptor.
     397             :   raw_fd_ostream(StringRef Filename, std::error_code &EC,
     398             :                  sys::fs::OpenFlags Flags);
     399             : 
     400             :   /// FD is the file descriptor that this writes to.  If ShouldClose is true,
     401             :   /// this closes the file when the stream is destroyed. If FD is for stdout or
     402             :   /// stderr, it will not be closed.
     403             :   raw_fd_ostream(int fd, bool shouldClose, bool unbuffered=false);
     404             : 
     405             :   ~raw_fd_ostream() override;
     406             : 
     407             :   /// Manually flush the stream and close the file. Note that this does not call
     408             :   /// fsync.
     409             :   void close();
     410             : 
     411             :   bool supportsSeeking() { return SupportsSeeking; }
     412             : 
     413             :   /// Flushes the stream and repositions the underlying file descriptor position
     414             :   /// to the offset specified from the beginning of the file.
     415             :   uint64_t seek(uint64_t off);
     416             : 
     417             :   raw_ostream &changeColor(enum Colors colors, bool bold=false,
     418             :                            bool bg=false) override;
     419             :   raw_ostream &resetColor() override;
     420             : 
     421             :   raw_ostream &reverseColor() override;
     422             : 
     423             :   bool is_displayed() const override;
     424             : 
     425             :   bool has_colors() const override;
     426             : 
     427             :   /// Return the value of the flag in this raw_fd_ostream indicating whether an
     428             :   /// output error has been encountered.
     429             :   /// This doesn't implicitly flush any pending output.  Also, it doesn't
     430             :   /// guarantee to detect all errors unless the stream has been closed.
     431             :   bool has_error() const {
     432             :     return Error;
     433             :   }
     434             : 
     435             :   /// Set the flag read by has_error() to false. If the error flag is set at the
     436             :   /// time when this raw_ostream's destructor is called, report_fatal_error is
     437             :   /// called to report the error. Use clear_error() after handling the error to
     438             :   /// avoid this behavior.
     439             :   ///
     440             :   ///   "Errors should never pass silently.
     441             :   ///    Unless explicitly silenced."
     442             :   ///      - from The Zen of Python, by Tim Peters
     443             :   ///
     444             :   void clear_error() {
     445          10 :     Error = false;
     446             :   }
     447             : };
     448             : 
     449             : /// This returns a reference to a raw_ostream for standard output. Use it like:
     450             : /// outs() << "foo" << "bar";
     451             : raw_ostream &outs();
     452             : 
     453             : /// This returns a reference to a raw_ostream for standard error. Use it like:
     454             : /// errs() << "foo" << "bar";
     455             : raw_ostream &errs();
     456             : 
     457             : /// This returns a reference to a raw_ostream which simply discards output.
     458             : raw_ostream &nulls();
     459             : 
     460             : //===----------------------------------------------------------------------===//
     461             : // Output Stream Adaptors
     462             : //===----------------------------------------------------------------------===//
     463             : 
     464             : /// A raw_ostream that writes to an std::string.  This is a simple adaptor
     465             : /// class. This class does not encounter output errors.
     466             : class raw_string_ostream : public raw_ostream {
     467             :   std::string &OS;
     468             : 
     469             :   /// See raw_ostream::write_impl.
     470             :   void write_impl(const char *Ptr, size_t Size) override;
     471             : 
     472             :   /// Return the current position within the stream, not counting the bytes
     473             :   /// currently in the buffer.
     474         515 :   uint64_t current_pos() const override { return OS.size(); }
     475             : 
     476             : public:
     477     3152254 :   explicit raw_string_ostream(std::string &O) : OS(O) {}
     478             :   ~raw_string_ostream() override;
     479             : 
     480             :   /// Flushes the stream contents to the target string and returns  the string's
     481             :   /// reference.
     482             :   std::string& str() {
     483     2365054 :     flush();
     484     1179251 :     return OS;
     485             :   }
     486             : };
     487             : 
     488             : /// A raw_ostream that writes to an SmallVector or SmallString.  This is a
     489             : /// simple adaptor class. This class does not encounter output errors.
     490             : /// raw_svector_ostream operates without a buffer, delegating all memory
     491             : /// management to the SmallString. Thus the SmallString is always up-to-date,
     492             : /// may be used directly and there is no need to call flush().
     493             : class raw_svector_ostream : public raw_pwrite_stream {
     494             :   SmallVectorImpl<char> &OS;
     495             : 
     496             :   /// See raw_ostream::write_impl.
     497             :   void write_impl(const char *Ptr, size_t Size) override;
     498             : 
     499             :   void pwrite_impl(const char *Ptr, size_t Size, uint64_t Offset) override;
     500             : 
     501             :   /// Return the current position within the stream.
     502             :   uint64_t current_pos() const override;
     503             : 
     504             : public:
     505             :   /// Construct a new raw_svector_ostream.
     506             :   ///
     507             :   /// \param O The vector to write to; this should generally have at least 128
     508             :   /// bytes free to avoid any extraneous memory overhead.
     509    28434838 :   explicit raw_svector_ostream(SmallVectorImpl<char> &O) : OS(O) {
     510    14217419 :     SetUnbuffered();
     511             :   }
     512             : 
     513    28434587 :   ~raw_svector_ostream() override = default;
     514             : 
     515             :   void flush() = delete;
     516             : 
     517             :   /// Return a StringRef for the vector contents.
     518     8968698 :   StringRef str() { return StringRef(OS.data(), OS.size()); }
     519             : };
     520             : 
     521             : /// A raw_ostream that discards all output.
     522             : class raw_null_ostream : public raw_pwrite_stream {
     523             :   /// See raw_ostream::write_impl.
     524             :   void write_impl(const char *Ptr, size_t size) override;
     525             :   void pwrite_impl(const char *Ptr, size_t Size, uint64_t Offset) override;
     526             : 
     527             :   /// Return the current position within the stream, not counting the bytes
     528             :   /// currently in the buffer.
     529             :   uint64_t current_pos() const override;
     530             : 
     531             : public:
     532      506300 :   explicit raw_null_ostream() = default;
     533             :   ~raw_null_ostream() override;
     534             : };
     535             : 
     536             : class buffer_ostream : public raw_svector_ostream {
     537             :   raw_ostream &OS;
     538             :   SmallVector<char, 0> Buffer;
     539             : 
     540             : public:
     541        6189 :   buffer_ostream(raw_ostream &OS) : raw_svector_ostream(Buffer), OS(OS) {}
     542       10235 :   ~buffer_ostream() override { OS << str(); }
     543             : };
     544             : 
     545             : } // end namespace llvm
     546             : 
     547             : #endif // LLVM_SUPPORT_RAW_OSTREAM_H

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