llvm-6502/lib/Support/FormattedStream.cpp

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//===-- llvm/Support/FormattedStream.cpp - Formatted streams ----*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains the implementation of formatted_raw_ostream.
//
//===----------------------------------------------------------------------===//
#include "llvm/Support/FormattedStream.h"
using namespace llvm;
/// CountColumns - Examine the given char sequence and figure out which
/// column we end up in after output.
///
static unsigned CountColumns(unsigned Column, const char *Ptr, size_t Size) {
// Keep track of the current column by scanning the string for
// special characters
for (const char *End = Ptr + Size; Ptr != End; ++Ptr) {
++Column;
if (*Ptr == '\n' || *Ptr == '\r')
Column = 0;
else if (*Ptr == '\t')
// Assumes tab stop = 8 characters.
Column += (8 - (Column & 0x7)) & 0x7;
}
return Column;
}
/// ComputeColumn - Examine the current output and figure out which
/// column we end up in after output.
void formatted_raw_ostream::ComputeColumn() {
// The buffer may have been allocated underneath us.
if (Scanned == 0) Scanned = begin();
// Scan all characters added since our last scan to determine the new column.
ColumnScanned = CountColumns(ColumnScanned, Scanned, end() - Scanned);
// We're now current with everything in the buffer.
Scanned = end();
}
/// PadToColumn - Align the output to some column number.
///
/// \param NewCol - The column to move to.
/// \param MinPad - The minimum space to give after the most recent
/// I/O, even if the current column + minpad > newcol.
///
void formatted_raw_ostream::PadToColumn(unsigned NewCol) {
// Figure out what's in the buffer and add it to the column count.
ComputeColumn();
// Output spaces until we reach the desired column.
unsigned num = NewCol - ColumnScanned;
if (NewCol < ColumnScanned || num < 1)
num = 1;
// Keep a buffer of spaces handy to speed up processing.
const char *Spaces = " "
" ";
assert(num < MAX_COLUMN_PAD && "Unexpectedly large column padding");
write(Spaces, num);
}
void formatted_raw_ostream::write_impl(const char *Ptr, size_t Size) {
// Figure out what's in the buffer and add it to the column count.
ComputeColumn();
// Write the data to the underlying stream (which is unbuffered, so
// the data will be immediately written out).
TheStream->write(Ptr, Size);
// If this FormattedStream is unbuffered, scan the string that
// was just written to determine the new column.
if (Ptr == begin()) {
// Buffered mode. The buffer is being flushed; reset the scanning
// position to the beginning of the buffer.
assert(Ptr + Size == end() && "Buffer is not being fully flushed!");
Scanned = begin();
} else {
// Unbuffered mode. Immediately scan the string that was just
// written to determine the new column.
ColumnScanned = CountColumns(ColumnScanned, Ptr, Size);
}
}
/// fouts() - This returns a reference to a formatted_raw_ostream for
/// standard output. Use it like: fouts() << "foo" << "bar";
formatted_raw_ostream &llvm::fouts() {
static formatted_raw_ostream S(outs());
return S;
}
/// ferrs() - This returns a reference to a formatted_raw_ostream for
/// standard error. Use it like: ferrs() << "foo" << "bar";
formatted_raw_ostream &llvm::ferrs() {
static formatted_raw_ostream S(errs());
return S;
}