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Diffstat (limited to 'include/llvm/Support/raw_ostream.h')
-rw-r--r-- | include/llvm/Support/raw_ostream.h | 346 |
1 files changed, 346 insertions, 0 deletions
diff --git a/include/llvm/Support/raw_ostream.h b/include/llvm/Support/raw_ostream.h new file mode 100644 index 0000000..b67d126 --- /dev/null +++ b/include/llvm/Support/raw_ostream.h @@ -0,0 +1,346 @@ +//===--- raw_ostream.h - Raw output stream ----------------------*- C++ -*-===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file defines the raw_ostream class. +// +//===----------------------------------------------------------------------===// + +#ifndef LLVM_SUPPORT_RAW_OSTREAM_H +#define LLVM_SUPPORT_RAW_OSTREAM_H + +#include "llvm/ADT/StringExtras.h" +#include <cassert> +#include <cstring> +#include <string> +#include <iosfwd> + +namespace llvm { + class format_object_base; + template <typename T> + class SmallVectorImpl; + +/// 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 +/// a chunk at a time. +class raw_ostream { +private: + /// The buffer is handled in such a way that the buffer is + /// uninitialized, unbuffered, or out of space when OutBufCur >= + /// OutBufEnd. Thus a single comparison suffices to determine if we + /// need to take the slow path to write a single character. + /// + /// The buffer is in one of three states: + /// 1. Unbuffered (Unbuffered == true) + /// 1. Uninitialized (Unbuffered == false && OutBufStart == 0). + /// 2. Buffered (Unbuffered == false && OutBufStart != 0 && + /// OutBufEnd - OutBufStart >= 64). + char *OutBufStart, *OutBufEnd, *OutBufCur; + bool Unbuffered; + +public: + explicit raw_ostream(bool unbuffered=false) : Unbuffered(unbuffered) { + // Start out ready to flush. + OutBufStart = OutBufEnd = OutBufCur = 0; + } + + virtual ~raw_ostream() { + delete [] OutBufStart; + } + + /// tell - Return the current offset with the file. + uint64_t tell() { return current_pos() + GetNumBytesInBuffer(); } + + //===--------------------------------------------------------------------===// + // Configuration Interface + //===--------------------------------------------------------------------===// + + /// SetBufferSize - Set the internal buffer size to the specified amount + /// instead of the default. + void SetBufferSize(unsigned Size=4096) { + assert(Size >= 64 && + "Buffer size must be somewhat large for invariants to hold"); + flush(); + + delete [] OutBufStart; + OutBufStart = new char[Size]; + OutBufEnd = OutBufStart+Size; + OutBufCur = OutBufStart; + Unbuffered = false; + } + + /// SetUnbuffered - Set the streams buffering status. 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(); + + delete [] OutBufStart; + OutBufStart = OutBufEnd = OutBufCur = 0; + Unbuffered = true; + } + + unsigned GetNumBytesInBuffer() const { + return OutBufCur - OutBufStart; + } + + //===--------------------------------------------------------------------===// + // Data Output Interface + //===--------------------------------------------------------------------===// + + void flush() { + if (OutBufCur != OutBufStart) + flush_nonempty(); + } + + raw_ostream &operator<<(char C) { + if (OutBufCur >= OutBufEnd) + return write(C); + *OutBufCur++ = C; + return *this; + } + + raw_ostream &operator<<(unsigned char C) { + if (OutBufCur >= OutBufEnd) + return write(C); + *OutBufCur++ = C; + return *this; + } + + raw_ostream &operator<<(signed char C) { + if (OutBufCur >= OutBufEnd) + return write(C); + *OutBufCur++ = C; + return *this; + } + + raw_ostream &operator<<(const char *Str) { + // Inline fast path, particulary for constant strings where a + // sufficiently smart compiler will simplify strlen. + + unsigned Size = strlen(Str); + + // Make sure we can use the fast path. + if (OutBufCur+Size > OutBufEnd) + return write(Str, Size); + + memcpy(OutBufCur, Str, Size); + OutBufCur += Size; + return *this; + } + + raw_ostream &operator<<(const std::string& Str) { + write(Str.data(), Str.length()); + return *this; + } + + raw_ostream &operator<<(unsigned long N); + raw_ostream &operator<<(long N); + raw_ostream &operator<<(unsigned long long N); + raw_ostream &operator<<(long long N); + raw_ostream &operator<<(const void *P); + raw_ostream &operator<<(unsigned int N) { + this->operator<<(static_cast<unsigned long>(N)); + return *this; + } + + raw_ostream &operator<<(int N) { + this->operator<<(static_cast<long>(N)); + return *this; + } + + raw_ostream &operator<<(double N) { + this->operator<<(ftostr(N)); + return *this; + } + + raw_ostream &write(unsigned char C); + raw_ostream &write(const char *Ptr, unsigned Size); + + // Formatted output, see the format() function in Support/Format.h. + raw_ostream &operator<<(const format_object_base &Fmt); + + //===--------------------------------------------------------------------===// + // Subclass Interface + //===--------------------------------------------------------------------===// + +private: + /// write_impl - The is the piece of the class that is implemented + /// by subclasses. This writes the \args Size bytes starting at + /// \arg Ptr to the underlying stream. + /// + /// \invariant { Size > 0 } + virtual void write_impl(const char *Ptr, unsigned Size) = 0; + + // 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. + virtual uint64_t current_pos() = 0; + + //===--------------------------------------------------------------------===// + // Private Interface + //===--------------------------------------------------------------------===// +private: + /// 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. + void flush_nonempty(); +}; + +//===----------------------------------------------------------------------===// +// File Output Streams +//===----------------------------------------------------------------------===// + +/// raw_fd_ostream - A raw_ostream that writes to a file descriptor. +/// +class raw_fd_ostream : public raw_ostream { + int FD; + bool ShouldClose; + uint64_t pos; + + /// write_impl - See raw_ostream::write_impl. + virtual void write_impl(const char *Ptr, unsigned Size); + + /// current_pos - Return the current position within the stream, not + /// counting the bytes currently in the buffer. + virtual uint64_t current_pos() { return pos; } + +public: + /// raw_fd_ostream - Open the specified file for writing. If an + /// error occurs, information about the error is put into ErrorInfo, + /// and the stream should be immediately destroyed; the string will + /// be empty if no error occurred. + /// + /// \param Filename - The file to open. If this is "-" then the + /// stream will use stdout instead. + /// \param Binary - The file should be opened in binary mode on + /// platforms that support this distinction. + raw_fd_ostream(const char *Filename, bool Binary, std::string &ErrorInfo); + + /// 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. + raw_fd_ostream(int fd, bool shouldClose, + bool unbuffered=false) : raw_ostream(unbuffered), FD(fd), + ShouldClose(shouldClose) {} + + ~raw_fd_ostream(); + + /// close - Manually flush the stream and close the file. + void close(); + + /// tell - Return the current offset with the file. + uint64_t tell() { return pos + GetNumBytesInBuffer(); } + + /// seek - Flushes the stream and repositions the underlying file descriptor + /// positition to the offset specified from the beginning of the file. + uint64_t seek(uint64_t off); +}; + +/// raw_stdout_ostream - This is a stream that always prints to stdout. +/// +class raw_stdout_ostream : public raw_fd_ostream { + // An out of line virtual method to provide a home for the class vtable. + virtual void handle(); +public: + raw_stdout_ostream(); +}; + +/// raw_stderr_ostream - This is a stream that always prints to stderr. +/// +class raw_stderr_ostream : public raw_fd_ostream { + // An out of line virtual method to provide a home for the class vtable. + virtual void handle(); +public: + raw_stderr_ostream(); +}; + +/// outs() - 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"; +raw_ostream &errs(); + + +//===----------------------------------------------------------------------===// +// Output Stream Adaptors +//===----------------------------------------------------------------------===// + +/// raw_os_ostream - A raw_ostream that writes to an std::ostream. This is a +/// simple adaptor class. +class raw_os_ostream : public raw_ostream { + std::ostream &OS; + + /// write_impl - See raw_ostream::write_impl. + virtual void write_impl(const char *Ptr, unsigned Size); + + /// current_pos - Return the current position within the stream, not + /// counting the bytes currently in the buffer. + virtual uint64_t current_pos(); + +public: + raw_os_ostream(std::ostream &O) : OS(O) {} + ~raw_os_ostream(); + + /// tell - Return the current offset with the stream. + uint64_t tell(); +}; + +/// raw_string_ostream - A raw_ostream that writes to an std::string. This is a +/// simple adaptor class. +class raw_string_ostream : public raw_ostream { + std::string &OS; + + /// write_impl - See raw_ostream::write_impl. + virtual void write_impl(const char *Ptr, unsigned Size); + + /// current_pos - Return the current position within the stream, not + /// counting the bytes currently in the buffer. + virtual uint64_t current_pos() { return OS.size(); } +public: + raw_string_ostream(std::string &O) : OS(O) {} + ~raw_string_ostream(); + + /// tell - Return the current offset with the stream. + uint64_t tell() { return OS.size() + GetNumBytesInBuffer(); } + + /// str - 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. +class raw_svector_ostream : public raw_ostream { + SmallVectorImpl<char> &OS; + + /// write_impl - See raw_ostream::write_impl. + virtual void write_impl(const char *Ptr, unsigned Size); + + /// current_pos - Return the current position within the stream, not + /// counting the bytes currently in the buffer. + virtual uint64_t current_pos(); +public: + raw_svector_ostream(SmallVectorImpl<char> &O) : OS(O) {} + ~raw_svector_ostream(); + + /// tell - Return the current offset with the stream. + uint64_t tell(); +}; + +} // end llvm namespace + +#endif |