formatter.py

#!/usr/bin/env python3
# encoding: utf-8
"""Format the ill-formatted code."""
## ==============================================
## GOAL : Format code, Update headers
## ==============================================

import argparse
import logging
import os
import re
import sys
import datetime
import subprocess

from functools import reduce

# Following is done so that we can import from ../helpers.py
sys.path.append(
    os.path.abspath(os.path.dirname(__file__)).replace('/formatting', '')
    )
from helpers import CLANG_FORMAT, PELOTON_DIR, CLANG_FORMAT_FILE, LOG,\
clang_format, hunks_from_staged_files, hunks_from_last_commits

## ==============================================
## CONFIGURATION
## ==============================================

# NOTE: absolute path to peloton directory is calculated from current directory
# directory structure: peloton/scripts/formatting/<this_file>
# PELOTON_DIR needs to be redefined if the directory structure is changed

#other directory paths used are relative to peloton_dir
PELOTON_SRC_DIR = os.path.join(PELOTON_DIR, "src")
PELOTON_TESTS_DIR = os.path.join(PELOTON_DIR, "test")

# DEFAULT DIRS
DEFAULT_DIRS = []
DEFAULT_DIRS.append(PELOTON_SRC_DIR)
DEFAULT_DIRS.append(PELOTON_TESTS_DIR)

## ==============================================
##             HEADER CONFIGURATION
## ==============================================

#header framework, dynamic information will be added inside function
header_comment_line_1 =  "//===----------------------------------------------------------------------===//\n"
header_comment_line_1 += "//\n"
header_comment_line_1 += "//                         Peloton\n"
header_comment_line_2  = "//\n"
header_comment_line_3  = "// "
header_comment_line_4  = "//\n"
header_comment_line_5  = "// Identification: "
header_comment_line_6  = "//\n"
header_comment_line_7  = "// Copyright (c) 2015-%d, Carnegie Mellon University Database Group\n" % datetime.datetime.now().year
header_comment_line_8  = "//\n"
header_comment_line_9  = "//===----------------------------------------------------------------------===//\n\n"

header_comment_1 = header_comment_line_1 + header_comment_line_2
header_comment_3 = header_comment_line_4
header_comment_5 = header_comment_line_6 + header_comment_line_7 \
+ header_comment_line_8 + header_comment_line_9

#regular expresseion used to track header
HEADER_REGEX = re.compile(r"((\/\/===-*===\/\/\n(\/\/.*\n)*\/\/===-*===\/\/[\n]*)\n\n)*")

## ==============================================
##           UTILITY FUNCTION DEFINITIONS
## ==============================================


def format_file(file_path, file_hunks, update_header, clang_format_code):
    """Formats the file passed as argument."""
    file_name = os.path.basename(file_path)
    abs_path = os.path.abspath(file_path)
    rel_path_from_peloton_dir = os.path.relpath(abs_path, PELOTON_DIR)

    with open(file_path, "r+") as file:
        file_data = file.read()

        if update_header:
            # strip old header if it exists
            header_match = HEADER_REGEX.match(file_data)
            if not header_match is None:
                LOG.info("Strip header from %s", file_name)
                header_comment = header_match.group()
                LOG.debug("Header comment : %s", header_comment)
                file_data = file_data.replace(header_comment,"")

            # add new header
            LOG.info("Add header to %s", file_name)
            header_comment_2 = header_comment_line_3 + file_name + "\n"
            header_comment_4 = header_comment_line_5\
            + rel_path_from_peloton_dir + "\n"
            header_comment = header_comment_1 + header_comment_2 \
            + header_comment_3 + header_comment_4 \
            + header_comment_5
            #print header_comment

            file_data = header_comment + file_data

            file.seek(0, 0)
            file.truncate()
            file.write(file_data)

        elif clang_format_code:
            clang_format(file_path, file_hunks)

    #END WITH
#END FORMAT__FILE(FILE_NAME)


def format_dir(dir_path, update_header, clang_format_code):
    """Formats all the files in the dir passed as argument."""
    for subdir, _, files in os.walk(dir_path):  # _ is for directories.
        for file in files:
            #print os.path.join(subdir, file)
            file_path = subdir + os.path.sep + file

            if file_path.endswith(".h") or file_path.endswith(".cpp"):
                format_file(file_path, None, update_header, clang_format_code)
            #END IF
        #END FOR [file]
    #END FOR [os.walk]
#END ADD_HEADERS_DIR(DIR_PATH)


## ==============================================
##                 Main Function
## ==============================================

if __name__ == '__main__':

    PARSER = argparse.ArgumentParser(
        description='Update headers and/or format source code'
        )

    PARSER.add_argument(
        "-u", "--update-header",
        help='Action: Update existing headers or add new ones',
        action='store_true'
        )
    PARSER.add_argument(
        "-c", "--clang-format-code",
        help='Action: Apply clang-format to source code',
        action='store_true'
        )
    PARSER.add_argument(
        "-f", "--staged-files",
        help='Action: Apply the selected action(s) to all staged files (git). ' + 
        '(clang-format will only touch the staged lines)',
        action='store_true'
        )
    PARSER.add_argument(
        "-n", "--number-commits",
        help='Action: Apply the selected action(s) to all changes of the last ' + 
        '<n> commits (clang-format will only touch the changed lines)',
        type=int, default=0
        )
    PARSER.add_argument(
        'paths', metavar='PATH', type=str, nargs='*',
        help='Files or directories to (recursively) apply the actions to'
        )

    ARGS = PARSER.parse_args()

    # TARGETS is a list of files with an optional list of hunks, represented as
    # pair (start, end) of line numbers, 1 based. 
    # element of TARGETS: (filename, None) or (filename, [(start,end)])

    if ARGS.staged_files:
        TARGETS = hunks_from_staged_files()

        if not TARGETS:
            LOG.error(
                "no staged files or not calling from a repository -- exiting"
                )
            sys.exit("no staged files or not calling from a repository")
            
    elif ARGS.number_commits > 0:
        TARGETS = hunks_from_last_commits(ARGS.number_commits)

        if not TARGETS:
            LOG.error(
                "no changes could be extracted for formatting -- exiting"
                )
            sys.exit("no changes could be extracted for formatting")
      
    elif not ARGS.paths:
        LOG.error("no files or directories given -- exiting")
        sys.exit("no files or directories given")
        
    else:
        TARGETS = [(f, None) for f in ARGS.paths]

    for f, hunks in TARGETS:
        if os.path.isfile(f):
            LOG.info("Scanning file: %s", f)
            format_file(f, hunks, ARGS.update_header, ARGS.clang_format_code)
        elif os.path.isdir(f):
            LOG.info("Scanning directory %s", f)
            format_dir(f, ARGS.update_header, ARGS.clang_format_code)
    ## FOR
## IF