compiler.py

#!/usr/bin/env python3

"""Compiler module

Acts as the command line interface to the compiler components. When given a
source file, the compilation process will be executed.

Author: Evan Sneath
License: Open Software License v3.0

Functions:
    parse_arguments: Parses incoming command line arguments.
    run_compiler: Executes the complete compilation process.
"""

# Import standard libraries
import argparse
import subprocess
import sys

# Import custom compiler libraries
from lib.parser import Parser


def parse_arguments():
    """Parse Arguments

    Parses all command line arguments for the compiler program.

    Returns:
        An object containing all expected command line arguments.
    """
    # Parse the command line arguments
    parser = argparse.ArgumentParser()
    parser.add_argument('-d', '--debug',
                        help='print comments in generated code',
                        action='store_true')
    parser.add_argument('source',
                        help='source file to compile')
    parser.add_argument('-o', '--out',
                        help='target path for the compiled code',
                        action='store',
                        default='a.out')
    args = parser.parse_args()

    return args


def run_compiler(source, target, debug=False):
    """Run Compiler

    Executes the compilation process given a source file path.

    Arguments:
        source: The source file to compile.
        target: The destination binary executable file.
        debug: If True, verbose parsing details are shown. (Default: False)

    Returns:
        True on success, False otherwise.
    """
    # Define a temporary location for the intermediate C code
    TMP_CODE_FILE = './ir.c'

    # Create a Parser object to parse the inputted source file
    parser = Parser(debug)

    # Parse the source file to the temporary code file
    if not parser.parse(source, TMP_CODE_FILE):
        print('Error while parsing "%s"' % source)
        return False

    # Set up gcc compilation command
    gcc_cmd = ['gcc', '-m32', '-o', target, TMP_CODE_FILE]

    # Compile the temporary file with gcc. Output to the target location
    if subprocess.call(gcc_cmd) != 0:
        print('Error while compiling "%s"' % target)
        return False

    return True


if __name__ == '__main__':
    # Parse compiler arguments
    args = parse_arguments()

    # Run compilation process
    result = run_compiler(args.source, args.out, debug=args.debug)

    # Terminate program
    sys.exit(not result)