llvm-mirror/lib/Support/FormattedStream.cpp
Daniel Malea 85afac7f62 Add line tracking support to FormattedStream
- previously formatted_raw_ostream tracked columns, now it tracks lines too
- used by (upcoming) DebugIR pass to know the line number to connect to each IR
  instruction

llvm-svn: 181463
2013-05-08 20:29:10 +00:00

107 lines
3.4 KiB
C++

//===-- 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/Debug.h"
#include "llvm/Support/FormattedStream.h"
#include <algorithm>
using namespace llvm;
/// UpdatePosition - Examine the given char sequence and figure out which
/// column we end up in after output, and how many line breaks are contained.
///
static void UpdatePosition(std::pair<unsigned, unsigned> &Position, const char *Ptr, size_t Size) {
unsigned &Column = Position.first;
unsigned &Line = Position.second;
// Keep track of the current column and line by scanning the string for
// special characters
for (const char *End = Ptr + Size; Ptr != End; ++Ptr) {
++Column;
switch (*Ptr) {
case '\n':
Line += 1;
case '\r':
Column = 0;
break;
case '\t':
// Assumes tab stop = 8 characters.
Column += (8 - (Column & 0x7)) & 0x7;
break;
}
}
}
/// ComputePosition - Examine the current output and update line and column
/// counts.
void formatted_raw_ostream::ComputePosition(const char *Ptr, size_t Size) {
// If our previous scan pointer is inside the buffer, assume we already
// scanned those bytes. This depends on raw_ostream to not change our buffer
// in unexpected ways.
if (Ptr <= Scanned && Scanned <= Ptr + Size)
// Scan all characters added since our last scan to determine the new
// column.
UpdatePosition(Position, Scanned, Size - (Scanned - Ptr));
else
UpdatePosition(Position, Ptr, Size);
// Update the scanning pointer.
Scanned = Ptr + Size;
}
/// PadToColumn - Align the output to some column number.
///
/// \param NewCol - The column to move to.
///
formatted_raw_ostream &formatted_raw_ostream::PadToColumn(unsigned NewCol) {
// Figure out what's in the buffer and add it to the column count.
ComputePosition(getBufferStart(), GetNumBytesInBuffer());
// Output spaces until we reach the desired column.
indent(std::max(int(NewCol - getColumn()), 1));
return *this;
}
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.
ComputePosition(Ptr, Size);
// Write the data to the underlying stream (which is unbuffered, so
// the data will be immediately written out).
TheStream->write(Ptr, Size);
// Reset the scanning pointer.
Scanned = 0;
}
/// 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;
}
/// fdbgs() - This returns a reference to a formatted_raw_ostream for
/// the debug stream. Use it like: fdbgs() << "foo" << "bar";
formatted_raw_ostream &llvm::fdbgs() {
static formatted_raw_ostream S(dbgs());
return S;
}