/*

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 *

 */

// FILEBUFF.CPP - Routines for handling a parser file buffer

#include "adlc.hpp"

//------------------------------FileBuff---------------------------------------

// Create a new parsing buffer

FileBuff::FileBuff( BufferedFile *fptr, ArchDesc& archDesc) : _fp(fptr), _AD(archDesc) {

  _err = fseek(_fp->_fp, 0, SEEK_END);  // Seek to end of file

  if (_err) {

    file_error(SEMERR, 0, "File seek error reading input file");

    exit(1);                    // Exit on seek error

  }

  _filepos = ftell(_fp->_fp);   // Find offset of end of file

  _bufferSize = _filepos + 5;   // Filepos points to last char, so add padding

  _err = fseek(_fp->_fp, 0, SEEK_SET);  // Reset to beginning of file

  if (_err) {

    file_error(SEMERR, 0, "File seek error reading input file\n");

    exit(1);                    // Exit on seek error

  }

  _filepos = ftell(_fp->_fp);      // Reset current file position

  _linenum = 0;

  _bigbuf = new char[_bufferSize]; // Create buffer to hold text for parser

  if( !_bigbuf ) {

    file_error(SEMERR, 0, "Buffer allocation failed\n");

    exit(1);                    // Exit on allocation failure

  }

  *_bigbuf = '\n';               // Lead with a sentinal newline

  _buf = _bigbuf+1;                     // Skip sentinal

  _bufmax = _buf;               // Buffer is empty

  _bufeol = _bigbuf;              // _bufeol points at sentinal

  _filepos = -1;                 // filepos is in sync with _bufeol

  _bufoff = _offset = 0L;       // Offset at file start

  _bufmax += fread(_buf, 1, _bufferSize-2, _fp->_fp); // Fill buffer & set end value

  if (_bufmax == _buf) {

    file_error(SEMERR, 0, "File read error, no input read\n");

    exit(1);                     // Exit on read error

  }

  *_bufmax = '\n';               // End with a sentinal new-line

  *(_bufmax+1) = '\0';           // Then end with a sentinal NULL

}

//------------------------------~FileBuff--------------------------------------

// Nuke the FileBuff

FileBuff::~FileBuff() {

  delete _bigbuf;

}

//------------------------------get_line----------------------------------------

char *FileBuff::get_line(void) {

  char *retval;

  // Check for end of file & return NULL

  if (_bufeol >= _bufmax) return NULL;

  _linenum++;

  retval = ++_bufeol;      // return character following end of previous line

  if (*retval == '\0') return NULL; // Check for EOF sentinal

  // Search for newline character which must end each line

  for(_filepos++; *_bufeol != '\n'; _bufeol++)

    _filepos++;                    // keep filepos in sync with _bufeol

  // _bufeol & filepos point at end of current line, so return pointer to start

  return retval;

}

//------------------------------FileBuffRegion---------------------------------

// Create a new region in a FileBuff.

FileBuffRegion::FileBuffRegion( FileBuff* bufr, int soln, int ln,

                                int off, int len)

: _bfr(bufr), _sol(soln), _line(ln), _offset(off), _length(len) {

  _next = NULL;                 // No chained regions

}

//------------------------------~FileBuffRegion--------------------------------

// Delete the entire linked list of buffer regions.

FileBuffRegion::~FileBuffRegion() {

  if( _next ) delete _next;

}

//------------------------------copy-------------------------------------------

// Deep copy a FileBuffRegion

FileBuffRegion *FileBuffRegion::copy() {

  if( !this ) return NULL;      // The empty buffer region

  FileBuffRegion *br = new FileBuffRegion(_bfr,_sol,_line,_offset,_length);

  if( _next ) br->_next = _next->copy();

  return br;

}

//------------------------------merge------------------------------------------

// Merge another buffer region into this buffer region.  Make overlapping areas

// become a single region.  Remove (delete) the input FileBuffRegion.

// Since the buffer regions are sorted by file offset, this is a varient of a

// "sorted-merge" running in linear time.

FileBuffRegion *FileBuffRegion::merge( FileBuffRegion *br ) {

  if( !br ) return this;        // Merging nothing

  if( !this ) return br;        // Merging into nothing

  assert( _bfr == br->_bfr, "" );     // Check for pointer-equivalent buffers

  if( _offset < br->_offset ) { // "this" starts before "br"

    if( _offset+_length < br->_offset ) { // "this" ends before "br"

      if( _next ) _next->merge( br );    // Merge with remainder of list

      else _next = br;                 // No more in this list; just append.

    } else {                           // Regions overlap.

      int l = br->_offset + br->_length - _offset;

      if( l > _length ) _length = l;     // Pick larger region

      FileBuffRegion *nr = br->_next;     // Get rest of region

      br->_next = NULL;         // Remove indication of rest of region

      delete br;                // Delete this region (it's been subsumed).

      if( nr ) merge( nr );     // Merge with rest of region

    }                           // End of if regions overlap or not.

  } else {                      // "this" starts after "br"

    if( br->_offset+br->_length < _offset ) {    // "br" ends before "this"

      FileBuffRegion *nr = new FileBuffRegion(_bfr,_sol,_line,_offset,_length);

      nr->_next = _next;                // Structure copy "this" guy to "nr"

      *this = *br;              // Structure copy "br" over "this".

      br->_next = NULL;         // Remove indication of rest of region

      delete br;                // Delete this region (it's been copied)

      merge( nr );              // Finish merging

    } else {                    // Regions overlap.

      int l = _offset + _length - br->_offset;

      if( l > _length ) _length = l;    // Pick larger region

      _offset = br->_offset;            // Start with earlier region

      _sol = br->_sol;                  // Also use earlier line start

      _line = br->_line;                        // Also use earlier line

      FileBuffRegion *nr = br->_next;   // Get rest of region

      br->_next = NULL;         // Remove indication of rest of region

      delete br;                // Delete this region (it's been subsumed).

      if( nr ) merge( nr );     // Merge with rest of region

    }                           // End of if regions overlap or not.

  }

  return this;

}

//------------------------------expandtab--------------------------------------

static int expandtab( ostream &os, int off, char c, char fill1, char fill2 ) {

  if( c == '\t' ) {             // Tab?

    do os << fill1;             // Expand the tab; Output space

    while( (++off) & 7 );       // Expand to tab stop

  } else {                      // Normal character

    os << fill2;                // Display normal character

    off++;                      // Increment "cursor" offset

  }

  return off;

}

//------------------------------printline--------------------------------------

// Print and highlite a region of a line.  Return the amount of highliting left

// to do (i.e. highlite length minus length of line).

static int printline( ostream& os, const char *fname, int line,

                        const char *_sol, int skip, int len ) {

  // Display the entire tab-expanded line

  os << fname << ":" << line << ": ";

  const char *t = strchr(_sol,'\n')+1; // End of line

  int off = 0;                  // Cursor offset for tab expansion

  const char *s = _sol;         // Nice string pointer

  while( t-s ) {                // Display whole line

    char c = *s++;              // Get next character to display

    off = expandtab(os,off,c,' ',c);

  }

  // Display the tab-expanded skippings before underlining.

  os << fname << ":" << line << ": ";

  off = 0;                      // Cursor offset for tab expansion

  s = _sol;                     // Restart string pointer

  // Start underlining.

  if( skip != -1 ) {            // The no-start-indicating flag

    const char *u = _sol+skip;  // Amount to skip

    while( u-s )                // Display skipped part

      off = expandtab(os,off,*s++,' ',' ');

    os << '^';                  // Start region

    off++;                      // Moved cursor

    len--;                      // 1 less char to do

    if( *s++ == '\t' )          // Starting character is a tab?

      off = expandtab(os,off,'\t','-','^');

  }

  // Long region doesn't end on this line

  int llen = (int)(t-s);        // Length of line, minus what's already done

  if( len > llen ) {            // Doing entire rest of line?

    while( t-s )                // Display rest of line

      off = expandtab(os,off,*s++,'-','-');

    os << '\n';                 // EOL

    return len-llen;            // Return what's not yet done.

  }

  // Region does end on this line.  This code fails subtly if the region ends

  // in a tab character.

  int i;

  for( i=1; i<len; i++ )        // Underline just what's needed

    off = expandtab(os,off,*s++,'-','-');

  if( i == len ) os << '^';     // Mark end of region

  os << '\n';                   // End of marked line

  return 0L;                    // All done

}

//------------------------------print------------------------------------------

//std::ostream& operator<< ( std::ostream& os, FileBuffRegion &br ) {

ostream& operator<< ( ostream& os, FileBuffRegion &br ) {

  if( &br == NULL ) return os;  // The empty buffer region

  FileBuffRegion *brp = &br;    // Pointer to region

  while( brp ) {                // While have chained regions

    brp->print(os);             // Print region

    brp = brp->_next;           // Chain to next

  }

  return os;                    // Return final stream

}

//------------------------------print------------------------------------------

// Print the FileBuffRegion to a stream. FileBuffRegions are printed with the

// filename and line number to the left, and complete text lines to the right.

// Selected portions (portions of a line actually in the FileBuffRegion are

// underlined.  Ellipses are used for long multi-line regions.

//void FileBuffRegion::print( std::ostream& os ) {

void FileBuffRegion::print( ostream& os ) {

  if( !this ) return;           // Nothing to print

  char *s = _bfr->get_line();

  int skip = (int)(_offset - _sol);     // Amount to skip to start of data

  int len = printline( os, _bfr->_fp->_name, _line, s, skip, _length );

  if( !len ) return;                    // All done; exit

  // Here we require at least 2 lines

  int off1 = _length - len + skip;      // Length of line 1

  int off2 = off1 + _sol;               // Offset to start of line 2

  char *s2 = _bfr->get_line();           // Start of line 2

  char *s3 = strchr( s2, '\n' )+1;      // Start of line 3 (unread)

  if( len <= (s3-s2) ) {                // It all fits on the next line

    printline( os, _bfr->_fp->_name, _line+1, s2, -1, len ); // Print&underline

    return;

  }

  // Here we require at least 3 lines

  int off3 = off2 + (int)(s3-s2);       // Offset to start of line 3

  s3 = _bfr->get_line();                // Start of line 3 (read)

  const char *s4 = strchr( s3, '\n' )+1;// Start of line 4 (unread)

  if( len < (s4-s3) ) {                 // It all fits on the next 2 lines

    s2 = _bfr->get_line();

    len = printline( os, _bfr->_fp->_name, _line+1, s2, -1, len ); // Line 2

    s3 = _bfr->get_line();

    printline( os, _bfr->_fp->_name, _line+2, s3, -1, len );     // Line 3

    return;

  }

  // Here we require at least 4 lines.

  // Print only the 1st and last line, with ellipses in middle.

  os << "...\n";                // The ellipses

  int cline = _line+1;          // Skipped 2 lines

  do {                          // Do until find last line

    len -= (int)(s3-s2);        // Remove length of line

    cline++;                    // Next line

    s2 = _bfr->get_line();      // Get next line from end of this line

    s3 = strchr( s2, '\n' ) + 1;// Get end of next line

  } while( len > (s3-s2) );     // Repeat until last line

  printline( os, _bfr->_fp->_name, cline, s2, -1, len ); // Print & underline

}

//------------------------------file_error-------------------------------------

void FileBuff::file_error(int flag, int linenum, const char *fmt, ...)

{

  va_list args;

  va_start(args, fmt);

  switch (flag) {

  case 0: _AD._warnings += _AD.emit_msg(0, flag, linenum, fmt, args);

  case 1: _AD._syntax_errs += _AD.emit_msg(0, flag, linenum, fmt, args);

  case 2: _AD._semantic_errs += _AD.emit_msg(0, flag, linenum, fmt, args);

  default: assert(0, ""); break;

  }

  va_end(args);

  _AD._no_output = 1;

}