lib/Support/raw_ostream.cpp

   1 //===--- raw_ostream.cpp - Implement the raw_ostream classes --------------===//
   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 implements support for bulk buffered stream output.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "llvm/Support/raw_ostream.h"
  15 #include "llvm/Support/Format.h"
  16 #include "llvm/System/Program.h"
  17 #include "llvm/ADT/SmallVector.h"
  18 #include "llvm/Config/config.h"
  19 #include "llvm/Support/Compiler.h"
  20 #include <ostream>
  21
  22 #if defined(HAVE_UNISTD_H)
  23 # include <unistd.h>
  24 #endif
  25 #if defined(HAVE_FCNTL_H)
  26 # include <fcntl.h>
  27 #endif
  28
  29 #if defined(_MSC_VER)
  30 #include <io.h>
  31 #include <fcntl.h>
  32 #ifndef STDIN_FILENO
  33 # define STDIN_FILENO 0
  34 #endif
  35 #ifndef STDOUT_FILENO
  36 # define STDOUT_FILENO 1
  37 #endif
  38 #ifndef STDERR_FILENO
  39 # define STDERR_FILENO 2
  40 #endif
  41 #endif
  42
  43 using namespace llvm;
  44
  45
  46 // An out of line virtual method to provide a home for the class vtable.
  47 void raw_ostream::handle() {}
  48
  49 raw_ostream &raw_ostream::operator<<(unsigned long N) {
  50   // Zero is a special case.
  51   if (N == 0)
  52     return *this << '0';
  53
  54   char NumberBuffer[20];
  55   char *EndPtr = NumberBuffer+sizeof(NumberBuffer);
  56   char *CurPtr = EndPtr;
  57
  58   while (N) {
  59     *--CurPtr = '0' + char(N % 10);
  60     N /= 10;
  61   }
  62   return write(CurPtr, EndPtr-CurPtr);
  63 }
  64
  65 raw_ostream &raw_ostream::operator<<(long N) {
  66   if (N <  0) {
  67     *this << '-';
  68     N = -N;
  69   }
  70
  71   return this->operator<<(static_cast<unsigned long>(N));
  72 }
  73
  74 raw_ostream &raw_ostream::operator<<(unsigned long long N) {
  75   // Zero is a special case.
  76   if (N == 0)
  77     return *this << '0';
  78
  79   char NumberBuffer[20];
  80   char *EndPtr = NumberBuffer+sizeof(NumberBuffer);
  81   char *CurPtr = EndPtr;
  82
  83   while (N) {
  84     *--CurPtr = '0' + char(N % 10);
  85     N /= 10;
  86   }
  87   return write(CurPtr, EndPtr-CurPtr);
  88 }
  89
  90 raw_ostream &raw_ostream::operator<<(long long N) {
  91   if (N <  0) {
  92     *this << '-';
  93     N = -N;
  94   }
  95
  96   return this->operator<<(static_cast<unsigned long long>(N));
  97 }
  98
  99 raw_ostream &raw_ostream::operator<<(const void *P) {
 100   uintptr_t N = (uintptr_t) P;
 101   *this << '0' << 'x';
 102
 103   // Zero is a special case.
 104   if (N == 0)
 105     return *this << '0';
 106
 107   char NumberBuffer[20];
 108   char *EndPtr = NumberBuffer+sizeof(NumberBuffer);
 109   char *CurPtr = EndPtr;
 110
 111   while (N) {
 112     unsigned x = N % 16;
 113     *--CurPtr = (x < 10 ? '0' + x : 'a' + x - 10);
 114     N /= 16;
 115   }
 116
 117   return write(CurPtr, EndPtr-CurPtr);
 118 }
 119
 120 void raw_ostream::flush_nonempty() {
 121   assert(OutBufCur > OutBufStart && "Invalid call to flush_nonempty.");
 122   write_impl(OutBufStart, OutBufCur - OutBufStart);
 123   OutBufCur = OutBufStart;
 124 }
 125
 126 raw_ostream &raw_ostream::write(unsigned char C) {
 127   // Group exceptional cases into a single branch.
 128   if (OutBufCur >= OutBufEnd) {
 129     if (Unbuffered) {
 130       write_impl(reinterpret_cast<char*>(&C), 1);
 131       return *this;
 132     }
 133
 134     if (!OutBufStart)
 135       SetBufferSize();
 136     else
 137       flush_nonempty();
 138   }
 139
 140   *OutBufCur++ = C;
 141   return *this;
 142 }
 143
 144 raw_ostream &raw_ostream::write(const char *Ptr, unsigned Size) {
 145   // Group exceptional cases into a single branch.
 146   if (BUILTIN_EXPECT(OutBufCur+Size > OutBufEnd, false)) {
 147     if (Unbuffered) {
 148       write_impl(Ptr, Size);
 149       return *this;
 150     }
 151
 152     if (!OutBufStart)
 153       SetBufferSize();
 154     else
 155       flush_nonempty();
 156   }
 157
 158   // Handle short strings specially, memcpy isn't very good at very short
 159   // strings.
 160   switch (Size) {
 161   case 4: OutBufCur[3] = Ptr[3]; // FALL THROUGH
 162   case 3: OutBufCur[2] = Ptr[2]; // FALL THROUGH
 163   case 2: OutBufCur[1] = Ptr[1]; // FALL THROUGH
 164   case 1: OutBufCur[0] = Ptr[0]; // FALL THROUGH
 165   case 0: break;
 166   default:
 167     // Normally the string to emit is shorter than the buffer.
 168     if (Size <= unsigned(OutBufEnd-OutBufStart)) {
 169       memcpy(OutBufCur, Ptr, Size);
 170       break;
 171     }
 172
 173     // Otherwise we are emitting a string larger than our buffer. We
 174     // know we already flushed, so just write it out directly.
 175     write_impl(Ptr, Size);
 176     Size = 0;
 177     break;
 178   }
 179   OutBufCur += Size;
 180
 181   return *this;
 182 }
 183
 184 // Formatted output.
 185 raw_ostream &raw_ostream::operator<<(const format_object_base &Fmt) {
 186   // If we have more than a few bytes left in our output buffer, try
 187   // formatting directly onto its end.
 188   //
 189   // FIXME: This test is a bit silly, since if we don't have enough
 190   // space in the buffer we will have to flush the formatted output
 191   // anyway. We should just flush upfront in such cases, and use the
 192   // whole buffer as our scratch pad. Note, however, that this case is
 193   // also necessary for correctness on unbuffered streams.
 194   unsigned NextBufferSize = 127;
 195   if (OutBufEnd-OutBufCur > 3) {
 196     unsigned BufferBytesLeft = OutBufEnd-OutBufCur;
 197     unsigned BytesUsed = Fmt.print(OutBufCur, BufferBytesLeft);
 198
 199     // Common case is that we have plenty of space.
 200     if (BytesUsed < BufferBytesLeft) {
 201       OutBufCur += BytesUsed;
 202       return *this;
 203     }
 204
 205     // Otherwise, we overflowed and the return value tells us the size to try
 206     // again with.
 207     NextBufferSize = BytesUsed;
 208   }
 209
 210   // If we got here, we didn't have enough space in the output buffer for the
 211   // string.  Try printing into a SmallVector that is resized to have enough
 212   // space.  Iterate until we win.
 213   SmallVector<char, 128> V;
 214
 215   while (1) {
 216     V.resize(NextBufferSize);
 217
 218     // Try formatting into the SmallVector.
 219     unsigned BytesUsed = Fmt.print(&V[0], NextBufferSize);
 220
 221     // If BytesUsed fit into the vector, we win.
 222     if (BytesUsed <= NextBufferSize)
 223       return write(&V[0], BytesUsed);
 224
 225     // Otherwise, try again with a new size.
 226     assert(BytesUsed > NextBufferSize && "Didn't grow buffer!?");
 227     NextBufferSize = BytesUsed;
 228   }
 229 }
 230
 231 //===----------------------------------------------------------------------===//
 232 //  Formatted Output
 233 //===----------------------------------------------------------------------===//
 234
 235 // Out of line virtual method.
 236 void format_object_base::home() {
 237 }
 238
 239 //===----------------------------------------------------------------------===//
 240 //  raw_fd_ostream
 241 //===----------------------------------------------------------------------===//
 242
 243 /// raw_fd_ostream - Open the specified file for writing. If an error
 244 /// occurs, information about the error is put into ErrorInfo, and the
 245 /// stream should be immediately destroyed; the string will be empty
 246 /// if no error occurred.
 247 raw_fd_ostream::raw_fd_ostream(const char *Filename, bool Binary,
 248                                std::string &ErrorInfo) : pos(0) {
 249   ErrorInfo.clear();
 250
 251   // Handle "-" as stdout.
 252   if (Filename[0] == '-' && Filename[1] == 0) {
 253     FD = STDOUT_FILENO;
 254     // If user requested binary then put stdout into binary mode if
 255     // possible.
 256     if (Binary)
 257       sys::Program::ChangeStdoutToBinary();
 258     ShouldClose = false;
 259     return;
 260   }
 261
 262   int Flags = O_WRONLY|O_CREAT|O_TRUNC;
 263 #ifdef O_BINARY
 264   if (Binary)
 265     Flags |= O_BINARY;
 266 #endif
 267   FD = open(Filename, Flags, 0644);
 268   if (FD < 0) {
 269     ErrorInfo = "Error opening output file '" + std::string(Filename) + "'";
 270     ShouldClose = false;
 271   } else {
 272     ShouldClose = true;
 273   }
 274 }
 275
 276 raw_fd_ostream::~raw_fd_ostream() {
 277   if (FD >= 0) {
 278     flush();
 279     if (ShouldClose)
 280       ::close(FD);
 281   }
 282 }
 283
 284 void raw_fd_ostream::write_impl(const char *Ptr, unsigned Size) {
 285   assert (FD >= 0 && "File already closed.");
 286   pos += Size;
 287   ::write(FD, Ptr, Size);
 288 }
 289
 290 void raw_fd_ostream::close() {
 291   assert (ShouldClose);
 292   ShouldClose = false;
 293   flush();
 294   ::close(FD);
 295   FD = -1;
 296 }
 297
 298 uint64_t raw_fd_ostream::seek(uint64_t off) {
 299   flush();
 300   pos = lseek(FD, off, SEEK_SET);
 301   return pos;
 302 }
 303
 304 //===----------------------------------------------------------------------===//
 305 //  raw_stdout/err_ostream
 306 //===----------------------------------------------------------------------===//
 307
 308 raw_stdout_ostream::raw_stdout_ostream():raw_fd_ostream(STDOUT_FILENO, false) {}
 309 raw_stderr_ostream::raw_stderr_ostream():raw_fd_ostream(STDERR_FILENO, false,
 310                                                         true) {}
 311
 312 // An out of line virtual method to provide a home for the class vtable.
 313 void raw_stdout_ostream::handle() {}
 314 void raw_stderr_ostream::handle() {}
 315
 316 /// outs() - This returns a reference to a raw_ostream for standard output.
 317 /// Use it like: outs() << "foo" << "bar";
 318 raw_ostream &llvm::outs() {
 319   static raw_stdout_ostream S;
 320   return S;
 321 }
 322
 323 /// errs() - This returns a reference to a raw_ostream for standard error.
 324 /// Use it like: errs() << "foo" << "bar";
 325 raw_ostream &llvm::errs() {
 326   static raw_stderr_ostream S;
 327   return S;
 328 }
 329
 330 //===----------------------------------------------------------------------===//
 331 //  raw_os_ostream
 332 //===----------------------------------------------------------------------===//
 333
 334 raw_os_ostream::~raw_os_ostream() {
 335   flush();
 336 }
 337
 338 void raw_os_ostream::write_impl(const char *Ptr, unsigned Size) {
 339   OS.write(Ptr, Size);
 340 }
 341
 342 uint64_t raw_os_ostream::current_pos() { return OS.tellp(); }
 343
 344 uint64_t raw_os_ostream::tell() {
 345   return (uint64_t)OS.tellp() + GetNumBytesInBuffer();
 346 }
 347
 348 //===----------------------------------------------------------------------===//
 349 //  raw_string_ostream
 350 //===----------------------------------------------------------------------===//
 351
 352 raw_string_ostream::~raw_string_ostream() {
 353   flush();
 354 }
 355
 356 void raw_string_ostream::write_impl(const char *Ptr, unsigned Size) {
 357   OS.append(Ptr, Size);
 358 }
 359
 360 //===----------------------------------------------------------------------===//
 361 //  raw_svector_ostream
 362 //===----------------------------------------------------------------------===//
 363
 364 raw_svector_ostream::~raw_svector_ostream() {
 365   flush();
 366 }
 367
 368 void raw_svector_ostream::write_impl(const char *Ptr, unsigned Size) {
 369   OS.append(Ptr, Ptr + Size);
 370 }
 371
 372 uint64_t raw_svector_ostream::current_pos() { return OS.size(); }
 373
 374 uint64_t raw_svector_ostream::tell() {
 375   return OS.size() + GetNumBytesInBuffer();
 376 }