Use Doctests to test the behavior of annotate_ifdef_directives.

# Copyright (c) 2017-2019, The Tor Project, Inc.

# See LICENSE for licensing information

# This script iterates over a list of C files. For each file, it looks at the

# #if/#else C macros, and annotates them with comments explaining what they

# match.

#

# For example, it replaces this:

#

#  #ifdef HAVE_OCELOT

#   // 500 lines of ocelot code

#  #endif

#

# with this:

#

#  #ifdef HAVE_OCELOT

#   // 500 lines of ocelot code

#  #endif /* defined(HAVE_OCELOT) */

#

# Note that only #else and #endif lines are annotated.  Existing comments

# on those lines are removed.

r"""

This script iterates over a list of C files. For each file, it looks at the

#if/#else C macros, and annotates them with comments explaining what they

match.

For example, it replaces this kind of input...

>>> INPUT = '''

... #ifdef HAVE_OCELOT

...   C code here

... #if MIMSY == BOROGROVE

...   block 1

...   block 1

...   block 1

...   block 1

... #else

...   block 2

...   block 2

...   block 2

...   block 2

... #endif

... #endif

... '''

With this kind of output:

>>> EXPECTED_OUTPUT = '''

... #ifdef HAVE_OCELOT

...   C code here

... #if MIMSY == BOROGROVE

...   block 1

...   block 1

...   block 1

...   block 1

... #else /* !(MIMSY == BOROGROVE) */

...   block 2

...   block 2

...   block 2

...   block 2

... #endif /* MIMSY == BOROGROVE */

... #endif /* defined(HAVE_OCELOT) */

... '''

Here's how to use it:

>>> import sys

>>> if sys.version_info.major < 3: from cStringIO import StringIO

>>> if sys.version_info.major >= 3: from io import StringIO

>>> OUTPUT = StringIO()

>>> translate(StringIO(INPUT), OUTPUT)

>>> assert OUTPUT.getvalue() == EXPECTED_OUTPUT

Note that only #else and #endif lines are annotated.  Existing comments

on those lines are removed.

"""

import re

def close_parens_needed(expr):

    """Return the number of left-parentheses needed to make 'expr'

       balanced.

    >>> close_parens_needed("1+2")

    0

    >>> close_parens_needed("(1 + 2)")

    0

    >>> close_parens_needed("(1 + 2")

    1

    >>> close_parens_needed("(1 + (2 *")

    2

    >>> close_parens_needed("(1 + (2 * 3) + (4")

    2

    """

    return expr.count("(") - expr.count(")")

       characters long.

       Try to return an expression with balanced parentheses.

    >>> truncate_expression("1+2+3", 8)

    '1+2+3'

    >>> truncate_expression("1+2+3+4+5", 8)

    '1+2+3...'

    >>> truncate_expression("(1+2+3+4)", 8)

    '(1+2...)'

    >>> truncate_expression("(1+(2+3+4))", 8)

    '(1+...)'

    >>> truncate_expression("(((((((((", 8)

    '((...))'

    """

    if len(expr) <= new_width:

        # The expression is already short enough.

    return ellipsis

def commented_line(fmt, argument, maxwidth=LINE_WIDTH):

    """

    # (This is a raw docstring so that our doctests can use \.)

    r"""

    Return fmt%argument, for use as a commented line.  If the line would

    be longer than maxwidth, truncate argument.

    be longer than maxwidth, truncate argument but try to keep its

    parentheses balanced.

    Requires that fmt%"..." will fit into maxwidth characters.

    Requires that fmt ends with a newline.

    >>> commented_line("/* %s */\n", "hello world", 32)

    '/* hello world */\n'

    >>> commented_line("/* %s */\n", "hello world", 15)

    '/* hello... */\n'

    >>> commented_line("#endif /* %s */\n", "((1+2) && defined(FOO))", 32)

    '#endif /* ((1+2) && defi...) */\n'

    """

    assert fmt.endswith("\n")

    result = fmt % argument

        raise Problem("Missing #endif")

import sys,os

if sys.argv[1] == "--self-test":

    import doctest

    doctest.testmod()

    sys.exit(0)

for fn in sys.argv[1:]:

    with open(fn+"_OUT", 'w') as output_file:

        translate(open(fn, 'r'), output_file)