Merge remote-tracking branch 'tor-github/pr/1667'

   Add a C file with matching header to the Tor codebase.  Creates

   both files from templates, and adds them to the right include.am file.

   This script takes paths relative to the top-level tor directory. It

   expects to be run from that directory.

   This script creates files, and inserts them into include.am, also

   relative to the top-level tor directory.

   But the template content in those files is relative to tor's src

   directory. (This script strips "src" from the paths used to create

   templated comments and macros.)

   This script expects posix paths, so it should be run with a python

   where os.path is posixpath. (Rather than ntpath.) This probably means

   Linux, macOS, or BSD, although it might work on Windows if your python

   was compiled with mingw, MSYS, or cygwin.

   Example usage:

   % add_c_file.py ./src/feature/dirauth/ocelot.c

import re

import time

def topdir_file(name):

    """Strip opening "src" from a filename"""

    return os.path.relpath(name, './src')

def guard_macro(name):

    """Return the guard macro that should be used for the header file 'name'.

def tordir_file(fname):

    """Make fname relative to the current directory, which should be the

       top-level tor directory. Also performs basic path simplifications."""

    return os.path.normpath(os.path.relpath(fname))

def srcdir_file(tor_fname):

    """Make tor_fname relative to tor's "src" directory.

       Also performs basic path simplifications.

       (This function takes paths relative to the top-level tor directory,

       but outputs a path that is relative to tor's src directory.)"""

    return os.path.normpath(os.path.relpath(tor_fname, 'src'))

def guard_macro(src_fname):

    """Return the guard macro that should be used for the header file

       'src_fname'. This function takes paths relative to tor's src directory.

    """

    td = topdir_file(name).replace(".", "_").replace("/", "_").upper()

    td = src_fname.replace(".", "_").replace("/", "_").upper()

    return "TOR_{}".format(td)

def makeext(name, new_extension):

    """Replace the extension for the file called 'name' with 'new_extension'.

def makeext(fname, new_extension):

    """Replace the extension for the file called 'fname' with 'new_extension'.

       This function takes and returns paths relative to either the top-level

       tor directory, or tor's src directory, and returns the same kind

       of path.

    """

    base = os.path.splitext(name)[0]

    base = os.path.splitext(fname)[0]

    return base + "." + new_extension

def instantiate_template(template, output_fname):

def instantiate_template(template, tor_fname):

    """

    Fill in a template with string using the fields that should be used

    for 'output_fname'.

    for 'tor_fname'.

    This function takes paths relative to the top-level tor directory,

    but the paths in the completed template are relative to tor's src

    directory. (Except for one of the fields, which is just a basename).

    """

    src_fname = srcdir_file(tor_fname)

    names = {

        # The relative location of the header file.

        'header_path' : makeext(topdir_file(output_fname), "h"),

        'header_path' : makeext(src_fname, "h"),

        # The relative location of the C file file.

        'c_file_path' : makeext(topdir_file(output_fname), "c"),

        'c_file_path' : makeext(src_fname, "c"),

        # The truncated name of the file.

        'short_name' : os.path.basename(output_fname),

        'short_name' : os.path.basename(src_fname),

        # The current year, for the copyright notice

        'this_year' : time.localtime().tm_year,

        # An appropriate guard macro, for the header.

        'guard_macro' : guard_macro(output_fname),

        'guard_macro' : guard_macro(src_fname),

    }

    return template.format(**names)

# This template operates on paths relative to tor's src directory

HEADER_TEMPLATE = """\

/* Copyright (c) 2001 Matej Pfajfar.

 * Copyright (c) 2001-2004, Roger Dingledine.

#endif /* !defined({guard_macro}) */

"""

# This template operates on paths relative to the tor's src directory

C_FILE_TEMPLATE = """\

/* Copyright (c) 2001 Matej Pfajfar.

 * Copyright (c) 2001-2004, Roger Dingledine.

    Represents part of an automake file.  If it is decorated with

    an ADD_C_FILE comment, it has a "kind" based on what to add to it.

    Otherwise, it only has a bunch of lines in it.

    This class operates on paths relative to the top-level tor directory.

    """

    pat = re.compile(r'# ADD_C_FILE: INSERT (\S*) HERE', re.I)

    def __init__(self):

        self.lines = []

        self.kind = ""

        self.hasBlank = False # true if we end with a blank line.

    def addLine(self, line):

        """

        Insert a line into this chunk while parsing the automake file.

        Return True if we have just read the last line in the chunk, and

        False otherwise.

        """

        m = self.pat.match(line)

        if m:

                raise ValueError("control line not preceded by a blank line")

            self.kind = m.group(1)

        self.lines.append(line)

        if line.strip() == "":

            self.hasBlank = True

            return True

        self.lines.append(line)

        return False

    def insertMember(self, member):

    def insertMember(self, new_tor_fname):

        """

        Add a new member to this chunk.  Try to insert it in alphabetical

        order with matching indentation, but don't freak out too much if the

        source isn't consistent.

        Add a new file name new_tor_fname to this chunk.  Try to insert it in

        alphabetical order with matching indentation, but don't freak out too

        much if the source isn't consistent.

        Assumes that this chunk is of the form:

           FOOBAR = \

              X     \

              Y     \

              Z

        This function operates on paths relative to the top-level tor

        directory.

        """

        prespace = "\t"

        postspace = "\t\t"

            m = re.match(r'(\s+)(\S+)(\s+)\\', line)

            if not m:

                continue

            prespace, fname, postspace = m.groups()

            if fname > member:

                self.insert_before(lineno, member, prespace, postspace)

            prespace, cur_tor_fname, postspace = m.groups()

            if cur_tor_fname > new_tor_fname:

                self.insert_before(lineno, new_tor_fname, prespace, postspace)

                return

        self.insert_at_end(member, prespace, postspace)

        self.insert_at_end(new_tor_fname, prespace, postspace)

    def insert_before(self, lineno, member, prespace, postspace):

    def insert_before(self, lineno, new_tor_fname, prespace, postspace):

        self.lines.insert(lineno,

                          "{}{}{}\\\n".format(prespace, member, postspace))

                          "{}{}{}\\\n".format(prespace, new_tor_fname,

                                              postspace))

    def insert_at_end(self, member, prespace, postspace):

        lastline = self.lines[-1]

        self.lines[-1] += '{}\\\n'.format(postspace)

        self.lines.append("{}{}\n".format(prespace, member))

    def insert_at_end(self, new_tor_fname, prespace, postspace):

        lastline = self.lines[-1].strip()

        self.lines[-1] = '{}{}{}\\\n'.format(prespace, lastline, postspace)

        self.lines.append("{}{}\n".format(prespace, new_tor_fname))

    def dump(self, f):

        """Write all the lines in this chunk to the file 'f'."""

            if not line.endswith("\n"):

                f.write("\n")

        if self.hasBlank:

            f.write("\n")

class ParsedAutomake:

    """A sort-of-parsed automake file, with identified chunks into which

       headers and c files can be inserted.

       This class operates on paths relative to the top-level tor directory.

    """

    def __init__(self):

        self.chunks = []

        self.chunks.append(chunk)

        self.by_type[chunk.kind.lower()] = chunk

    def add_file(self, fname, kind):

        """Insert a file of kind 'kind' to the appropriate section of this

           file. Return True if we added it.

    def add_file(self, tor_fname, kind):

        """Insert a file tor_fname of kind 'kind' to the appropriate

           section of this file. Return True if we added it.

           This function operates on paths relative to the top-level tor

           directory.

        """

        if kind.lower() in self.by_type:

            self.by_type[kind.lower()].insertMember(fname)

            self.by_type[kind.lower()].insertMember(tor_fname)

            return True

        else:

            return False

        for chunk in self.chunks:

            chunk.dump(f)

def get_include_am_location(fname):

    """Find the right include.am file for introducing a new file.  Return None

       if we can't guess one.

def get_include_am_location(tor_fname):

    """Find the right include.am file for introducing a new file

       tor_fname.  Return None if we can't guess one.

       Note that this function is imperfect because our include.am layout is

       not (yet) consistent.

       This function operates on paths relative to the top-level tor directory.

    """

    td = topdir_file(fname)

    m = re.match(r'^(lib|core|feature|app)/([a-z0-9_]*)/', td)

    # Strip src for pattern matching, but add it back when returning the path

    src_fname = srcdir_file(tor_fname)

    m = re.match(r'^(lib|core|feature|app)/([a-z0-9_]*)/', src_fname)

    if m:

        return "src/{}/{}/include.am".format(m.group(1),m.group(2))

    if re.match(r'^test/', td):

    if re.match(r'^test/', src_fname):

        return "src/test/include.am"

    return None

def run(fn):

    """

    Create a new C file and H file corresponding to the filename "fn", and

    add them to include.am.

def run(fname):

    """

    Create a new C file and H file corresponding to the filename "fname",

    and add them to the corresponding include.am.

    cf = makeext(fn, "c")

    hf = makeext(fn, "h")

    This function operates on paths relative to the top-level tor directory.

    """

    if os.path.exists(cf):

        print("{} already exists".format(cf))

    # Make sure we're in the top-level tor directory,

    # which contains the src directory

    if not os.path.isdir("src"):

        raise RuntimeError("Could not find './src/'. "

                           "Run this script from the top-level tor source "

                           "directory.")

    # And it looks like a tor/src directory

    if not os.path.isfile("src/include.am"):

        raise RuntimeError("Could not find './src/include.am'. "

                           "Run this script from the top-level tor source "

                           "directory.")

    # Make the file name relative to the top-level tor directory

    tor_fname = tordir_file(fname)

    # And check that we're adding files to the "src" directory,

    # with canonical paths

    if tor_fname[:4] != "src/":

        raise ValueError("Requested file path '{}' canonicalized to '{}', "

                         "but the canonical path did not start with 'src/'. "

                         "Please add files to the src directory."

                         .format(fname, tor_fname))

    c_tor_fname = makeext(tor_fname, "c")

    h_tor_fname = makeext(tor_fname, "h")

    if os.path.exists(c_tor_fname):

        print("{} already exists".format(c_tor_fname))

        return 1

    if os.path.exists(hf):

        print("{} already exists".format(hf))

    if os.path.exists(h_tor_fname):

        print("{} already exists".format(h_tor_fname))

        return 1

    with open(cf, 'w') as f:

        f.write(instantiate_template(C_FILE_TEMPLATE, cf))

    with open(c_tor_fname, 'w') as f:

        f.write(instantiate_template(C_FILE_TEMPLATE, c_tor_fname))

    with open(hf, 'w') as f:

        f.write(instantiate_template(HEADER_TEMPLATE, hf))

    with open(h_tor_fname, 'w') as f:

        f.write(instantiate_template(HEADER_TEMPLATE, h_tor_fname))

    iam = get_include_am_location(cf)

    iam = get_include_am_location(c_tor_fname)

    if iam is None or not os.path.exists(iam):

        print("Made files successfully but couldn't identify include.am for {}"

              .format(cf))

              .format(c_tor_fname))

        return 1

    amfile = ParsedAutomake()

                cur_chunk = AutomakeChunk()

        amfile.addChunk(cur_chunk)

    amfile.add_file(cf, "sources")

    amfile.add_file(hf, "headers")

    amfile.add_file(c_tor_fname, "sources")

    amfile.add_file(h_tor_fname, "headers")

    with open(iam+".tmp", 'w') as f:

        amfile.dump(f)