Subversion Repositories ssbcc

#!/usr/bin/python2.7

################################################################################

#

# Copyright 2012, Sinclair R.F., Inc.

#

# Assembler for SSBCC 9x8 processor

#

################################################################################

# global modules

import argparse

import re

import sys

# User defined modules

import asmDef

################################################################################

#

# Surround the program with a try ... except clause

#

################################################################################

try:

  ################################################################################

  #

  # The main loop:

  #

  # - Process the command line arguments.

  #

  ################################################################################

  #

  # Construct the command-line argument list parser

  #

  def validateFile(filename):

    try:

      return file(filename,'r');

    except:

      raise asmDef.AsmException('Error opening "%s"' % filename);

  argListParser = argparse.ArgumentParser(description='SSBCC 9x8 assembler');

  argListParser.add_argument('-C', metavar='CONSTANT=value', action='append', help='Constant definition');

  argListParser.add_argument('-G', metavar='parametername', action='append', help='parameter names');

  argListParser.add_argument('-I', metavar='PORT=index', action='append', help='Input port names');

  argListParser.add_argument('-L', metavar='librarypath', action='append', help='Library search path');

  argListParser.add_argument('-O', metavar='PORT=index', action='append', help='Output port names');

  argListParser.add_argument('-R', metavar='PORT=index', action='append', help='Strobe-only output port names');

  argListParser.add_argument('-S', metavar='MEMORY=length', action='append', help='Memory length');

  argListParser.add_argument('-i', action='store_true', help='enable/require interrupt');

  argListParser.add_argument('-o', metavar='outfile', type=argparse.FileType('w'), required =True, help='output metafile');

  argListParser.add_argument('-s', metavar='STACK_NAME=length', action='append', help='Stack length');

  argListParser.add_argument('filename', metavar='filename', nargs='+', type=validateFile, help='required list of files');

  argList = argListParser.parse_args();

  # Construct the keyword parser

  from asmDef_9x8 import asmDef_9x8

  ad = asmDef_9x8();

  # Record the constants in the program symbol table.

  if argList.C:

    for constant in argList.C:

      a=re.findall(r'^(C_\w+)=(\w+)$',constant);

      if not a:

        raise asmDef.AsmException('Malformed -C argument: "%s"' % constant);

      a = list(a[0]);

      try:

        a[1] = eval(a[1]);

      except:

        raise asmDef.AsmException('Cannot evaluate "%s"' % a[1]);

      if ad.IsSymbol(a[0]):

        raise asmDef.AsmException('Command line constant "%s" already defined' % a[0]);

      ad.AddSymbol(a[0], 'constant', body=[a[1]]);

  # Record the input names and values in the appropriate record type

  if argList.G:

    for parameter in argList.G:

      a = re.findall(r'^([LG]_\w+)$',parameter);

      if not a:

        raise asmDef.AsmException('Malformed -G argument: "%s"' % parameter);

      if ad.IsSymbol(a[0]):

        raise asmDef.AsmException('Program Bug -- repeated symbol "%s"' % a[0]);

      ad.RegisterParameterName(a[0]);

  if argList.I:

    for inport in argList.I:

      a=re.findall(r'^(I_\w+)=(0|[1-9]\d*)$',inport);

      if not a:

        raise asmDef.AsmException('Malformed -I argument: "%s"' % inport);

      a = a[0];

      if ad.IsSymbol(a[0]):

        raise Exception('Program Bug -- repeated symbol "%s"' % a[0]);

      ix = int(a[1]);

      if not (0 <= ix < 256):

        raise asmDef.AsmException('Out-of-range inport index:  "%s"' % inport);

      ad.RegisterInport(a[0],ix);

  if argList.O:

    for outport in argList.O:

      a=re.findall(r'^(O_\w+)=(0|[1-9]\d*)$',outport);

      if not a:

        raise asmDef.AsmException('Malformed -O argument: "%s"' % outport);

      a = a[0];

      if ad.IsSymbol(a[0]):

        raise asmDef.AsmException('Program Bug -- repeated symbol "%s"' % a[0]);

      ix = int(a[1]);

      if not (0 <= ix < 256):

        raise asmDef.AsmException('Out-of-range outport index:  "%s"' % outport);

      ad.RegisterOutport(a[0],ix);

  if argList.R:

    for outstrobe in argList.R:

      a=re.findall(r'^(O_\w+)=(0|[1-9]\d*)$',outstrobe);

      if not a:

        raise asmDef.AsmException('Malformed -R argument: "%s"' % outstrobe);

      a = a[0];

      if ad.IsSymbol(a[0]):

        raise asmDef.AsmException('Program Bug -- repeated symbol "%s"' % a[0]);

      ix = int(a[1]);

      if not (0 <= ix < 256):

        raise asmDef.AsmException('Out-of-range strobe-only outport index:  "%s"' % outstrobe);

      ad.RegisterOutstrobe(a[0],ix);

  if argList.S:

    for memory in argList.S:

      a=re.findall(r'^(\w+)=(0|[1-9]\d*)$',memory);

      if not a:

        raise asmDef.AsmException('Malformed -S argument: "%s"' % memory);

      a=a[0];

      length = int(a[1]);

      if not (0 < length <= 256):

        raise asmDef.AsmException('Out-of-range memory length:  "%s"' % outport);

      ad.RegisterMemoryLength(a[0],length);

  if argList.s:

    for stack in argList.s:

      a=re.findall(r'^(\w+)=(0|[1-9]\d*)$',stack);

      if not a:

        raise asmDef.AsmException('Malformed -s argument: "%s"' % stack);

      a = a[0];

      ad.RegisterStackLength(a[0],int(a[1]));

  # Construct the iterator that loops through the code bodies.

  fbi = asmDef.FileBodyIterator(argList.filename,ad);

  if argList.L:

    for path in argList.L:

      fbi.AddSearchPath(path);

  ################################################################################

  #

  # Stage 1:  Parse the files.

  #

  # Read the entire file, doing the following while reading the file:

  # - Store the raw content of each line or group of lines for output to the

  #   assembled memory initialization.

  #   Note: A group of lines consists the comment lines preceding a directive and

  #         the body of the directive.

  # - Convert group of lines into an array of the raw tokens.

  # - Check the integrity of the bodies defined by the list of raw tokens.

  # - For each array of raw tokens, incorporate already-defined symbols and update

  #   the assembler dictionaries.

  #   Note: At this point the space required for the function or main program

  #     is fully computed.

  #

  ################################################################################

  #

  # Loop through the directive bodies in the input files (including ".include"d

  # files).

  #

  ifstackStack = list();

  ifstack = None;

  for bl in fbi:

    filename = bl[0];

    startLine = bl[1];

    body = bl[2:];

    flc_loc = filename + ' at line ' + str(startLine+len(body)-1);

    # Start-of-file processing.

    if startLine == 0:

      if ifstack != None:

        ifstackStack.append(ifstack);

      ifstack = list();

    # End-of-file processing.

    elif startLine == -1:

      if len(ifstack) != 0:

        raise asmDef.AsmException('%d unmatched .IFDEF/.IFNDEF(s) at the end of %s' % (len(ifstack),filename,));

      if ifstackStack:

        ifstack = ifstackStack.pop();

      else:

        ifstack = None;

    # Handle conditional compilation directives.

    elif re.match(r'\s*\.ELSE\b',body[-1]):

      if not re.match(r'\s*\.ELSE\s*(;.*)?$',body[-1]):

        raise asmDef.AsmException('Malformed ".ELSE" in %s' % flc_loc);

      if not ifstack:

        raise asmDef.AsmException('Unmatched ".ELSE" in %s' % flc_loc);

      ifstack[-1] ^= True;

    elif re.match(r'\s*\.ENDIF\b',body[-1]):

      if not re.match(r'\s*\.ENDIF\s*(;.*)?$',body[-1]):

        raise asmDef.AsmException('Malformed ".ENDIF" in %s' % flc_loc);

      if not ifstack:

        raise asmDef.AsmException('Unmatched ".ENDIF" in %s' % flc_loc);

      ifstack.pop();

    elif re.match(r'\s*\.IFN?DEF\b',body[-1]):

      a = re.findall(r'\s*(\.IFN?DEF)\s*(\S+)\b\s*(;.*)?$',body[-1]);

      if not a:

        raise asmDef.AsmException('Malformed .IFDEF or .IFNDEF in %s' % flc_loc);

      a = a[0];

      ifstack.append(ad.IsSymbol(a[1]));

      if a[0] == '.IFNDEF':

        ifstack[-1] ^= True;

    # Ignore bodies rejected by conditional compilation.

    elif ifstack and not ifstack[-1]:

      pass;

    # ".include" directives don't have an associated body

    elif re.match(r'\s*\.include\s',body[-1]):

      a = re.findall(r'\s*\.include\s+(\S+)(\s*|\s*;.*)$',body[-1]);

      if not a:

        raise asmDef.AsmException('Malformed .include directive in %s' % flc_loc);

      a = a[0];

      fbi.Include(a[0]);

    # Parse the body of all other directives and ensure that only one ".main"

    # and one ".interrupt" are defined.

    else:

      rawTokens = asmDef.RawTokens(ad,filename,startLine,body);

      if not rawTokens:

        continue;

      ad.CheckRawTokens(rawTokens);

      ad.FillRawTokens(rawTokens);

  #

  # Ensure a ".main" body was declared.

  #

  if not ad.Main():

    raise asmDef.AsmException('Required ".main" body not provided');

  #

  # Enforce consistency between the command-line "-i" flag and whether or not an

  # ".interrupt" body was declared.

  #

  if argList.i and not ad.Interrupt():

    raise asmDef.AsmException('Required ".interrupt" body not provided');

  if not argList.i and ad.Interrupt():

    raise asmDef.AsmException('".interrupt" body not allowed near %s' % ad.Interrupt()[0]['loc']);

  ################################################################################

  #

  # Stage 2:  Identify the required functions, compute their addresses, and set

  # the addresses for all "jump" and "call" macros.

  #

  ################################################################################

  ad.EvaluateMemoryTree();

  ad.EvaluateFunctionTree();

  ################################################################################

  #

  # Stage 3:  Emit the program

  #

  # Do the following:

  # - If interrupts are enabled, then set the first 4 instructions to be a "dis"

  #   and a ".jump" instruction to the ".interrupt" function.

  # - Write the instructions for the ".main" body.

  # - Loop through the ".function" list in the order in which they were defined

  #   and write their instructions.

  # - Print the memory and instruction usage statistics.

  #

  ################################################################################

  ad.EmitMemories(argList.o);

  ad.EmitProgram(argList.o);

  argList.o.close();

################################################################################

#

# Terminating except clause -- print fatal error message and indicate failure to

# the invoking program.

#

################################################################################

except asmDef.AsmException, msg:

  print >> sys.stderr, 'FATAL ERROR:  ' + str(msg);

  exit(1);