Errors.py

#/*-------------------------------------------------------------------------
#Errors.py -- Error handling routines
#Compiler Generator Coco/R,
#Copyright (c) 1990, 2004 Hanspeter Moessenboeck, University of Linz
#extended by M. Loeberbauer & A. Woess, Univ. of Linz
#ported from Java to Python by Ronald Longo
#
#This program is free software; you can redistribute it and/or modify it
#under the terms of the GNU General Public License as published by the
#Free Software Foundation; either version 2, or (at your option) any
#later version.
#
#This program 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
#for more details.
#
#You should have received a copy of the GNU General Public License along
#with this program; if not, write to the Free Software Foundation, Inc.,
#59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
#
#As an exception, it is allowed to write an extension of Coco/R that is
#used as a plugin in non-free software.
#
#If not otherwise stated, any source code generated by Coco/R (other than
#Coco/R itself) does not fall under the GNU General Public License.
#-------------------------------------------------------------------------*/
import sys

class ErrorRec( object ):
   def __init__( self, l, c, s ):
      self.line   = l
      self.col    = c
      self.num    = 0
      self.str    = s

class Errors( object ):
   errMsgFormat = "file %(file)s : (%(line)s, %(col)s) %(text)s\n"
   eof          = False
   count        = 0         # number of errors detected
   fileName     = ''
   listName     = ''
   mergeErrors  = False
   mergedList   = None      # PrintWriter
   errors       = [ ]
   minErrDist   = 2
   errDist      = minErrDist
      # A function with prototype: f( errorNum=None ) where errorNum is a
      # predefined error number.  f returns a tuple, ( line, column, message )
      # such that line and column refer to the location in the
      # source file most recently parsed.  message is the error
      # message corresponging to errorNum.

   @staticmethod
   def Init( fn, dir, merge, getParsingPos, errorMessages ):
      Errors.theErrors = [ ]
      Errors.getParsingPos = getParsingPos
      Errors.errorMessages = errorMessages
      Errors.fileName = fn
      listName = dir + 'listing.txt'
      Errors.mergeErrors = merge
      if Errors.mergeErrors:
         try:
            Errors.mergedList = open( listName, 'w' )
         except IOError:
            raise RuntimeError( '-- Compiler Error: could not open ' + listName )

   @staticmethod
   def storeError( line, col, s ):
      if Errors.mergeErrors:
         Errors.errors.append( ErrorRec( line, col, s ) )
      else:
         Errors.printMsg( Errors.fileName, line, col, s )

   @staticmethod
   def SynErr( errNum, errPos=None ):
      line,col = errPos if errPos else Errors.getParsingPos( )
      msg = Errors.errorMessages[ errNum ]
      Errors.storeError( line, col, msg )
      Errors.count += 1

   @staticmethod
   def SemErr( errMsg, errPos=None ):
      line,col = errPos if errPos else Errors.getParsingPos( )
      Errors.storeError( line, col, errMsg )
      Errors.count += 1

   @staticmethod
   def Warn( errMsg, errPos=None ):
      line,col = errPos if errPos else Errors.getParsingPos( )
      Errors.storeError( line, col, errMsg )

   @staticmethod
   def Exception( errMsg ):
      print errMsg
      sys.exit( 1 )

   @staticmethod
   def printMsg( fileName, line, column, msg ):
      vals = { 'file':fileName, 'line':line, 'col':column, 'text':msg }
      sys.stdout.write( Errors.errMsgFormat % vals )

   @staticmethod
   def display( s, e ):
      Errors.mergedList.write('**** ')
      for c in xrange( 1, e.col ):
         if s[c-1] == '\t':
            Errors.mergedList.write( '\t' )
         else:
            Errors.mergedList.write( ' ' )
      Errors.mergedList.write( '^ ' + e.str + '\n')

   @staticmethod
   def Summarize( sourceBuffer ):
      if Errors.mergeErrors:
         # Initialize the line iterator
         srcLineIter = iter(sourceBuffer)
         srcLineStr  = srcLineIter.next( )
         srcLineNum  = 1

         try:
            # Initialize the error iterator
            errIter = iter(Errors.errors)
            errRec  = errIter.next( )

            # Advance to the source line of the next error
            while srcLineNum < errRec.line:
               Errors.mergedList.write( '%4d %s\n' % (srcLineNum, srcLineStr) )

               srcLineStr = srcLineIter.next( )
               srcLineNum += 1

            # Write out all errors for the current source line
            while errRec.line == srcLineNum:
               Errors.display( srcLineStr, errRec )

               errRec = errIter.next( )
         except:
            pass

         # No more errors to report
         try:
            # Advance to end of source file
            while True:
               Errors.mergedList.write( '%4d %s\n' % (srcLineNum, srcLineStr) )

               srcLineStr = srcLineIter.next( )
               srcLineNum += 1
         except:
            pass

         Errors.mergedList.write( '\n' )
         Errors.mergedList.write( '%d errors detected\n' % Errors.count )
         Errors.mergedList.close( )

      sys.stdout.write( '%d errors detected\n' % Errors.count )
      if (Errors.count > 0) and Errors.mergeErrors:
         sys.stdout.write( 'see ' + Errors.listName + '\n' )