Add #ifdef/#ifndef parsing

[Schamper]

Fixes #125

[codecov]

Codecov Report

❌ Patch coverage is 97.82609% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 92.95%. Comparing base (01afa28) to head (0e2918c).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
dissect/cstruct/parser.py	97.82%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #135      +/-   ##
==========================================
+ Coverage   92.74%   92.95%   +0.21%     
==========================================
  Files          21       21              
  Lines        2384     2427      +43     
==========================================
+ Hits         2211     2256      +45     
+ Misses        173      171       -2     

Flag	Coverage Δ
unittests	92.95% <97.82%> (+0.21%)	⬆️

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[andkae]

HI schamper, thanks for the changes. It still not work on my end, what is a little bit strange. But if i modify the regexp:

From:

TOK.add(r"#ifndef\s+(?P<name>[^\s]+)\s*(?=\s)", "IFNDEF")

To:

TOK.add(r"#ifndef\s+(?P<name>[^\s]+)\s*", "IFNDEF")

Then runs my example.

ChatGPT explains in that way:
This pattern breakdown is:

• #ifndef: Matches the literal text #ifndef.
• \s+: Matches one or more whitespace characters following the #ifndef.
• (?P[^\s]+): Named capturing group name that matches and captures one or more non-whitespace characters (the identifier).
• \s*: Matches zero or more whitespace characters following the identifier, making it optional.

This version will correctly match #ifndef __MYGUARD whether or not there is a space after __MYGUARD.

[Schamper]

I just tab-completed those patterns from Copilot so I'm blaming AI 😄. Changed it.

[andkae]

Another hint, if i run python3.9 -m pytest i recieved some error:

================================================= test session starts ==================================================
platform linux -- Python 3.9.5, pytest-8.4.1, pluggy-1.6.0
rootdir: /home/ubuntu/Desktop/guard
collected 515 items                                                                                                    

dissect.cstruct/tests/test_align.py ................                                                             [  3%]
dissect.cstruct/tests/test_annotations.py ...................................................................... [ 16%]
..................                                                                                               [ 20%]
dissect.cstruct/tests/test_basic.py ........F..............................                                      [ 27%]
dissect.cstruct/tests/test_bitbuffer.py .                                                                        [ 27%]
dissect.cstruct/tests/test_bitfield.py ....................                                                      [ 31%]
dissect.cstruct/tests/test_compiler.py ....................                                                      [ 35%]
dissect.cstruct/tests/test_ctypes.py .......                                                                     [ 37%]
dissect.cstruct/tests/test_expression.py ....................................................................... [ 50%]
                                                                                                                 [ 50%]
dissect.cstruct/tests/test_parser.py ............                                                                [ 53%]
dissect.cstruct/tests/test_tools_stubgen.py ............F..                                                      [ 56%]
dissect.cstruct/tests/test_types_base.py ......                                                                  [ 57%]
dissect.cstruct/tests/test_types_char.py ......                                                                  [ 58%]
dissect.cstruct/tests/test_types_custom.py ...                                                                   [ 59%]
dissect.cstruct/tests/test_types_enum.py ............................                                            [ 64%]
dissect.cstruct/tests/test_types_flag.py .................                                                       [ 67%]
dissect.cstruct/tests/test_types_int.py ...........................                                              [ 73%]
dissect.cstruct/tests/test_types_leb128.py .............                                                         [ 75%]
dissect.cstruct/tests/test_types_packed.py ...............                                                       [ 78%]
dissect.cstruct/tests/test_types_pointer.py ..............                                                       [ 81%]
dissect.cstruct/tests/test_types_structure.py .............................................                      [ 89%]
dissect.cstruct/tests/test_types_union.py ..........................                                             [ 94%]
dissect.cstruct/tests/test_types_void.py .......                                                                 [ 96%]
dissect.cstruct/tests/test_types_wchar.py ..........                                                             [ 98%]
dissect.cstruct/tests/test_utils.py .........                                                                    [100%]

[Schamper]

Fixed.

[andkae]

With cda868c it looks really good, it can handle define guards and also all unit tests.

Great work :) Thanks

[Miauwkeru]

I did found a condition where I expected the parser to break, but it just continued

    #ifndef __HELP
    #define __HELP
    #ifndef __MY_CONST
    struct test {
        uint32 a;
    };
    #endif

Is it an idea to check the length of self._conditionals and _conditional_depth at the end of the parsing, to see whether the conditionals where actually closed.