diff options
Diffstat (limited to 'include/llvm/Support/raw_ostream.h')
| -rw-r--r-- | include/llvm/Support/raw_ostream.h | 231 |
1 files changed, 129 insertions, 102 deletions
diff --git a/include/llvm/Support/raw_ostream.h b/include/llvm/Support/raw_ostream.h index 12783c7..338f0f4 100644 --- a/include/llvm/Support/raw_ostream.h +++ b/include/llvm/Support/raw_ostream.h @@ -20,21 +20,20 @@ #include <system_error> namespace llvm { - class format_object_base; - class FormattedString; - class FormattedNumber; - template <typename T> - class SmallVectorImpl; - - namespace sys { - namespace fs { - enum OpenFlags : unsigned; - } - } - -/// raw_ostream - This class implements an extremely fast bulk output stream -/// that can *only* output to a stream. It does not support seeking, reopening, -/// rewinding, line buffered disciplines etc. It is a simple buffer that outputs +class format_object_base; +class FormattedString; +class FormattedNumber; +template <typename T> class SmallVectorImpl; + +namespace sys { +namespace fs { +enum OpenFlags : unsigned; +} +} + +/// This class implements an extremely fast bulk output stream that can *only* +/// output to a stream. It does not support seeking, reopening, rewinding, line +/// buffered disciplines etc. It is a simple buffer that outputs /// a chunk at a time. class raw_ostream { private: @@ -81,8 +80,8 @@ public: SAVEDCOLOR }; - explicit raw_ostream(bool unbuffered=false) - : BufferMode(unbuffered ? Unbuffered : InternalBuffer) { + explicit raw_ostream(bool unbuffered = false) + : BufferMode(unbuffered ? Unbuffered : InternalBuffer) { // Start out ready to flush. OutBufStart = OutBufEnd = OutBufCur = nullptr; } @@ -96,12 +95,11 @@ public: // Configuration Interface //===--------------------------------------------------------------------===// - /// SetBuffered - Set the stream to be buffered, with an automatically - /// determined buffer size. + /// Set the stream to be buffered, with an automatically determined buffer + /// size. void SetBuffered(); - /// SetBufferSize - Set the stream to be buffered, using the - /// specified buffer size. + /// Set the stream to be buffered, using the specified buffer size. void SetBufferSize(size_t Size) { flush(); SetBufferAndMode(new char[Size], Size, InternalBuffer); @@ -117,10 +115,9 @@ public: return OutBufEnd - OutBufStart; } - /// SetUnbuffered - Set the stream to be unbuffered. When - /// unbuffered, the stream will flush after every write. This routine - /// will also flush the buffer immediately when the stream is being - /// set to unbuffered. + /// Set the stream to be unbuffered. When unbuffered, the stream will flush + /// after every write. This routine will also flush the buffer immediately + /// when the stream is being set to unbuffered. void SetUnbuffered() { flush(); SetBufferAndMode(nullptr, 0, Unbuffered); @@ -204,11 +201,11 @@ public: raw_ostream &operator<<(double N); - /// write_hex - Output \p N in hexadecimal, without any prefix or padding. + /// Output \p N in hexadecimal, without any prefix or padding. raw_ostream &write_hex(unsigned long long N); - /// write_escaped - Output \p Str, turning '\\', '\t', '\n', '"', and - /// anything that doesn't satisfy std::isprint into an escape sequence. + /// Output \p Str, turning '\\', '\t', '\n', '"', and anything that doesn't + /// satisfy std::isprint into an escape sequence. raw_ostream &write_escaped(StringRef Str, bool UseHexEscapes = false); raw_ostream &write(unsigned char C); @@ -263,8 +260,8 @@ public: //===--------------------------------------------------------------------===// private: - /// write_impl - The is the piece of the class that is implemented - /// by subclasses. This writes the \p Size bytes starting at + /// The is the piece of the class that is implemented by subclasses. This + /// writes the \p Size bytes starting at /// \p Ptr to the underlying stream. /// /// This function is guaranteed to only be called at a point at which it is @@ -281,51 +278,58 @@ private: // An out of line virtual method to provide a home for the class vtable. virtual void handle(); - /// current_pos - Return the current position within the stream, not - /// counting the bytes currently in the buffer. + /// Return the current position within the stream, not counting the bytes + /// currently in the buffer. virtual uint64_t current_pos() const = 0; protected: - /// SetBuffer - Use the provided buffer as the raw_ostream buffer. This is - /// intended for use only by subclasses which can arrange for the output to go - /// directly into the desired output buffer, instead of being copied on each - /// flush. + /// Use the provided buffer as the raw_ostream buffer. This is intended for + /// use only by subclasses which can arrange for the output to go directly + /// into the desired output buffer, instead of being copied on each flush. void SetBuffer(char *BufferStart, size_t Size) { SetBufferAndMode(BufferStart, Size, ExternalBuffer); } - /// preferred_buffer_size - Return an efficient buffer size for the - /// underlying output mechanism. + /// Return an efficient buffer size for the underlying output mechanism. virtual size_t preferred_buffer_size() const; - /// getBufferStart - Return the beginning of the current stream buffer, or 0 - /// if the stream is unbuffered. + /// Return the beginning of the current stream buffer, or 0 if the stream is + /// unbuffered. const char *getBufferStart() const { return OutBufStart; } //===--------------------------------------------------------------------===// // Private Interface //===--------------------------------------------------------------------===// private: - /// SetBufferAndMode - Install the given buffer and mode. + /// Install the given buffer and mode. void SetBufferAndMode(char *BufferStart, size_t Size, BufferKind Mode); - /// flush_nonempty - Flush the current buffer, which is known to be - /// non-empty. This outputs the currently buffered data and resets - /// the buffer to empty. + /// Flush the current buffer, which is known to be non-empty. This outputs the + /// currently buffered data and resets the buffer to empty. void flush_nonempty(); - /// copy_to_buffer - Copy data into the buffer. Size must not be - /// greater than the number of unused bytes in the buffer. + /// Copy data into the buffer. Size must not be greater than the number of + /// unused bytes in the buffer. void copy_to_buffer(const char *Ptr, size_t Size); }; +/// An abstract base class for streams implementations that also support a +/// pwrite operation. This is usefull for code that can mostly stream out data, +/// but needs to patch in a header that needs to know the output size. +class raw_pwrite_stream : public raw_ostream { +public: + explicit raw_pwrite_stream(bool Unbuffered = false) + : raw_ostream(Unbuffered) {} + virtual void pwrite(const char *Ptr, size_t Size, uint64_t Offset) = 0; +}; + //===----------------------------------------------------------------------===// // File Output Streams //===----------------------------------------------------------------------===// -/// raw_fd_ostream - A raw_ostream that writes to a file descriptor. +/// A raw_ostream that writes to a file descriptor. /// -class raw_fd_ostream : public raw_ostream { +class raw_fd_ostream : public raw_pwrite_stream { int FD; bool ShouldClose; @@ -339,18 +343,19 @@ class raw_fd_ostream : public raw_ostream { uint64_t pos; - /// write_impl - See raw_ostream::write_impl. + bool SupportsSeeking; + + /// See raw_ostream::write_impl. void write_impl(const char *Ptr, size_t Size) override; - /// current_pos - Return the current position within the stream, not - /// counting the bytes currently in the buffer. + /// Return the current position within the stream, not counting the bytes + /// currently in the buffer. uint64_t current_pos() const override { return pos; } - /// preferred_buffer_size - Determine an efficient buffer size. + /// Determine an efficient buffer size. size_t preferred_buffer_size() const override; - /// error_detected - Set the flag indicating that an output error has - /// been encountered. + /// Set the flag indicating that an output error has been encountered. void error_detected() { Error = true; } public: @@ -367,22 +372,26 @@ public: raw_fd_ostream(StringRef Filename, std::error_code &EC, sys::fs::OpenFlags Flags); - /// raw_fd_ostream ctor - FD is the file descriptor that this writes to. If - /// ShouldClose is true, this closes the file when the stream is destroyed. + /// FD is the file descriptor that this writes to. If ShouldClose is true, + /// this closes the file when the stream is destroyed. raw_fd_ostream(int fd, bool shouldClose, bool unbuffered=false); - ~raw_fd_ostream(); + ~raw_fd_ostream() override; - /// close - Manually flush the stream and close the file. - /// Note that this does not call fsync. + /// Manually flush the stream and close the file. Note that this does not call + /// fsync. void close(); - /// seek - Flushes the stream and repositions the underlying file descriptor - /// position to the offset specified from the beginning of the file. + bool supportsSeeking() { return SupportsSeeking; } + + /// Flushes the stream and repositions the underlying file descriptor position + /// to the offset specified from the beginning of the file. uint64_t seek(uint64_t off); - /// SetUseAtomicWrite - Set the stream to attempt to use atomic writes for - /// individual output routines where possible. + void pwrite(const char *Ptr, size_t Size, uint64_t Offset) override; + + /// Set the stream to attempt to use atomic writes for individual output + /// routines where possible. /// /// Note that because raw_ostream's are typically buffered, this flag is only /// sensible when used on unbuffered streams which will flush their output @@ -401,18 +410,18 @@ public: bool has_colors() const override; - /// has_error - Return the value of the flag in this raw_fd_ostream indicating - /// whether an output error has been encountered. + /// Return the value of the flag in this raw_fd_ostream indicating whether an + /// output error has been encountered. /// This doesn't implicitly flush any pending output. Also, it doesn't /// guarantee to detect all errors unless the stream has been closed. bool has_error() const { return Error; } - /// clear_error - Set the flag read by has_error() to false. If the error - /// flag is set at the time when this raw_ostream's destructor is called, - /// report_fatal_error is called to report the error. Use clear_error() - /// after handling the error to avoid this behavior. + /// Set the flag read by has_error() to false. If the error flag is set at the + /// time when this raw_ostream's destructor is called, report_fatal_error is + /// called to report the error. Use clear_error() after handling the error to + /// avoid this behavior. /// /// "Errors should never pass silently. /// Unless explicitly silenced." @@ -423,87 +432,105 @@ public: } }; -/// outs() - This returns a reference to a raw_ostream for standard output. -/// Use it like: outs() << "foo" << "bar"; +/// This returns a reference to a raw_ostream for standard output. Use it like: +/// outs() << "foo" << "bar"; raw_ostream &outs(); -/// errs() - This returns a reference to a raw_ostream for standard error. -/// Use it like: errs() << "foo" << "bar"; +/// This returns a reference to a raw_ostream for standard error. Use it like: +/// errs() << "foo" << "bar"; raw_ostream &errs(); -/// nulls() - This returns a reference to a raw_ostream which simply discards -/// output. +/// This returns a reference to a raw_ostream which simply discards output. raw_ostream &nulls(); //===----------------------------------------------------------------------===// // Output Stream Adaptors //===----------------------------------------------------------------------===// -/// raw_string_ostream - A raw_ostream that writes to an std::string. This is a -/// simple adaptor class. This class does not encounter output errors. +/// A raw_ostream that writes to an std::string. This is a simple adaptor +/// class. This class does not encounter output errors. class raw_string_ostream : public raw_ostream { std::string &OS; - /// write_impl - See raw_ostream::write_impl. + /// See raw_ostream::write_impl. void write_impl(const char *Ptr, size_t Size) override; - /// current_pos - Return the current position within the stream, not - /// counting the bytes currently in the buffer. + /// Return the current position within the stream, not counting the bytes + /// currently in the buffer. uint64_t current_pos() const override { return OS.size(); } public: explicit raw_string_ostream(std::string &O) : OS(O) {} - ~raw_string_ostream(); + ~raw_string_ostream() override; - /// str - Flushes the stream contents to the target string and returns - /// the string's reference. + /// Flushes the stream contents to the target string and returns the string's + /// reference. std::string& str() { flush(); return OS; } }; -/// raw_svector_ostream - A raw_ostream that writes to an SmallVector or -/// SmallString. This is a simple adaptor class. This class does not -/// encounter output errors. -class raw_svector_ostream : public raw_ostream { +/// A raw_ostream that writes to an SmallVector or SmallString. This is a +/// simple adaptor class. This class does not encounter output errors. +class raw_svector_ostream : public raw_pwrite_stream { SmallVectorImpl<char> &OS; - /// write_impl - See raw_ostream::write_impl. + /// See raw_ostream::write_impl. void write_impl(const char *Ptr, size_t Size) override; - /// current_pos - Return the current position within the stream, not - /// counting the bytes currently in the buffer. + /// Return the current position within the stream, not counting the bytes + /// currently in the buffer. uint64_t current_pos() const override; + +protected: + // Like the regular constructor, but doesn't call init. + explicit raw_svector_ostream(SmallVectorImpl<char> &O, unsigned); + void init(); + public: /// Construct a new raw_svector_ostream. /// /// \param O The vector to write to; this should generally have at least 128 /// bytes free to avoid any extraneous memory overhead. explicit raw_svector_ostream(SmallVectorImpl<char> &O); - ~raw_svector_ostream(); + ~raw_svector_ostream() override; - /// resync - This is called when the SmallVector we're appending to is changed - /// outside of the raw_svector_ostream's control. It is only safe to do this - /// if the raw_svector_ostream has previously been flushed. + void pwrite(const char *Ptr, size_t Size, uint64_t Offset) override; + + /// This is called when the SmallVector we're appending to is changed outside + /// of the raw_svector_ostream's control. It is only safe to do this if the + /// raw_svector_ostream has previously been flushed. void resync(); - /// str - Flushes the stream contents to the target vector and return a - /// StringRef for the vector contents. + /// Flushes the stream contents to the target vector and return a StringRef + /// for the vector contents. StringRef str(); }; -/// raw_null_ostream - A raw_ostream that discards all output. -class raw_null_ostream : public raw_ostream { - /// write_impl - See raw_ostream::write_impl. +/// A raw_ostream that discards all output. +class raw_null_ostream : public raw_pwrite_stream { + /// See raw_ostream::write_impl. void write_impl(const char *Ptr, size_t size) override; - /// current_pos - Return the current position within the stream, not - /// counting the bytes currently in the buffer. + /// Return the current position within the stream, not counting the bytes + /// currently in the buffer. uint64_t current_pos() const override; public: explicit raw_null_ostream() {} - ~raw_null_ostream(); + ~raw_null_ostream() override; + void pwrite(const char *Ptr, size_t Size, uint64_t Offset) override; +}; + +class buffer_ostream : public raw_svector_ostream { + raw_ostream &OS; + SmallVector<char, 0> Buffer; + +public: + buffer_ostream(raw_ostream &OS) : raw_svector_ostream(Buffer, 0), OS(OS) { + init(); + } + ~buffer_ostream() { OS << str(); } }; } // end llvm namespace |