llvm-6502/lib/Support/raw_ostream.cpp
Chris Lattner 097af7fc8f add a simple mechanism for formatted output. This gives raw_ostream's
all the power and risk of fprintf format strings.  Use them like this:

  OS << format("%10.4f", 42.0) << "\n" << format("%x", 42) << '\n';



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55246 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-23 19:23:10 +00:00

260 lines
7.1 KiB
C++

//===--- raw_ostream.cpp - Implement the raw_ostream classes --------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This implements support for bulk buffered stream output.
//
//===----------------------------------------------------------------------===//
#include "llvm/Support/raw_ostream.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/Config/config.h"
#include <ostream>
#if defined(HAVE_UNISTD_H)
# include <unistd.h>
#endif
#if defined(HAVE_FCNTL_H)
# include <fcntl.h>
#endif
#if defined(_MSC_VER)
#include <io.h>
#ifndef STDIN_FILENO
# define STDIN_FILENO 0
#endif
#ifndef STDOUT_FILENO
# define STDOUT_FILENO 1
#endif
#ifndef STDERR_FILENO
# define STDERR_FILENO 2
#endif
#endif
using namespace llvm;
// An out of line virtual method to provide a home for the class vtable.
void raw_ostream::handle() {}
raw_ostream &raw_ostream::operator<<(unsigned long N) {
// Zero is a special case.
if (N == 0)
return *this << '0';
char NumberBuffer[20];
char *EndPtr = NumberBuffer+sizeof(NumberBuffer);
char *CurPtr = EndPtr;
while (N) {
*--CurPtr = '0' + char(N % 10);
N /= 10;
}
return write(CurPtr, EndPtr-CurPtr);
}
raw_ostream &raw_ostream::operator<<(long N) {
if (N < 0) {
if (OutBufCur >= OutBufEnd)
flush_impl();
*OutBufCur++ = '-';
N = -N;
}
return this->operator<<(static_cast<unsigned long>(N));
}
raw_ostream &raw_ostream::operator<<(unsigned long long N) {
// Zero is a special case.
if (N == 0)
return *this << '0';
char NumberBuffer[20];
char *EndPtr = NumberBuffer+sizeof(NumberBuffer);
char *CurPtr = EndPtr;
while (N) {
*--CurPtr = '0' + char(N % 10);
N /= 10;
}
return write(CurPtr, EndPtr-CurPtr);
}
raw_ostream &raw_ostream::operator<<(long long N) {
if (N < 0) {
if (OutBufCur >= OutBufEnd)
flush_impl();
*OutBufCur++ = '-';
N = -N;
}
return this->operator<<(static_cast<unsigned long long>(N));
}
raw_ostream &raw_ostream::write(const char *Ptr, unsigned Size) {
if (OutBufCur+Size > OutBufEnd)
flush_impl();
// Handle short strings specially, memcpy isn't very good at very short
// strings.
switch (Size) {
case 4: OutBufCur[3] = Ptr[3]; // FALL THROUGH
case 3: OutBufCur[2] = Ptr[2]; // FALL THROUGH
case 2: OutBufCur[1] = Ptr[1]; // FALL THROUGH
case 1: OutBufCur[0] = Ptr[0]; // FALL THROUGH
case 0: break;
default:
// Normally the string to emit is shorter than the buffer.
if (Size <= unsigned(OutBufEnd-OutBufStart)) {
memcpy(OutBufCur, Ptr, Size);
break;
}
// If emitting a string larger than our buffer, emit in chunks. In this
// case we know that we just flushed the buffer.
while (Size) {
unsigned NumToEmit = OutBufEnd-OutBufStart;
if (Size < NumToEmit) NumToEmit = Size;
assert(OutBufCur == OutBufStart);
memcpy(OutBufStart, Ptr, NumToEmit);
Ptr += NumToEmit;
Size -= NumToEmit;
OutBufCur = OutBufStart + NumToEmit;
flush_impl();
}
break;
}
OutBufCur += Size;
return *this;
}
// Formatted output.
raw_ostream &raw_ostream::operator<<(const format_object_base &Fmt) {
// If we have more than a few bytes left in our output buffer, try formatting
// directly onto its end.
unsigned NextBufferSize = 127;
if (OutBufEnd-OutBufCur > 3) {
unsigned BufferBytesLeft = OutBufEnd-OutBufCur;
unsigned BytesUsed = Fmt.print(OutBufCur, BufferBytesLeft);
// Common case is that we have plenty of space.
if (BytesUsed < BufferBytesLeft) {
OutBufCur += BytesUsed;
return *this;
}
// Otherwise, we overflowed and the return value tells us the size to try
// again with.
NextBufferSize = BytesUsed;
}
// If we got here, we didn't have enough space in the output buffer for the
// string. Try printing into a SmallVector that is resized to have enough
// space. Iterate until we win.
SmallVector<char, 128> V;
while (1) {
V.resize(NextBufferSize);
// Try formatting into the SmallVector.
unsigned BytesUsed = Fmt.print(&V[0], NextBufferSize);
// If BytesUsed fit into the vector, we win.
if (BytesUsed < NextBufferSize)
return write(&V[0], BytesUsed);
// Otherwise, try again with a new size.
assert(BytesUsed > NextBufferSize && "Didn't grow buffer!?");
NextBufferSize = BytesUsed;
}
}
//===----------------------------------------------------------------------===//
// Formatted Output
//===----------------------------------------------------------------------===//
// Out of line virtual method.
void format_object_base::home() {
}
//===----------------------------------------------------------------------===//
// raw_fd_ostream
//===----------------------------------------------------------------------===//
/// 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.
raw_fd_ostream::raw_fd_ostream(const char *Filename, std::string &ErrorInfo) {
// Handle "-" as stdout.
if (Filename[0] == '-' && Filename[1] == 0) {
FD = STDOUT_FILENO;
ShouldClose = false;
return;
}
FD = open(Filename, O_WRONLY|O_CREAT|O_TRUNC, 0644);
if (FD < 0) {
ErrorInfo = "Error opening output file '" + std::string(Filename) + "'";
ShouldClose = false;
} else {
ShouldClose = true;
}
}
raw_fd_ostream::~raw_fd_ostream() {
flush();
if (ShouldClose)
close(FD);
}
void raw_fd_ostream::flush_impl() {
if (OutBufCur-OutBufStart)
::write(FD, OutBufStart, OutBufCur-OutBufStart);
HandleFlush();
}
//===----------------------------------------------------------------------===//
// raw_stdout/err_ostream
//===----------------------------------------------------------------------===//
raw_stdout_ostream::raw_stdout_ostream():raw_fd_ostream(STDOUT_FILENO, false) {}
raw_stderr_ostream::raw_stderr_ostream():raw_fd_ostream(STDERR_FILENO, false) {}
// An out of line virtual method to provide a home for the class vtable.
void raw_stdout_ostream::handle() {}
void raw_stderr_ostream::handle() {}
/// outs() - This returns a reference to a raw_ostream for standard output.
/// Use it like: outs() << "foo" << "bar";
raw_ostream &llvm::outs() {
static raw_stdout_ostream S;
return S;
}
/// errs() - This returns a reference to a raw_ostream for standard error.
/// Use it like: errs() << "foo" << "bar";
raw_ostream &llvm::errs() {
static raw_stderr_ostream S;
return S;
}
//===----------------------------------------------------------------------===//
// raw_os_ostream
//===----------------------------------------------------------------------===//
/// flush_impl - The is the piece of the class that is implemented by
/// subclasses. This outputs the currently buffered data and resets the
/// buffer to empty.
void raw_os_ostream::flush_impl() {
if (OutBufCur-OutBufStart)
OS.write(OutBufStart, OutBufCur-OutBufStart);
HandleFlush();
}