C++ Source Extractor

C++ Source Extractor is a Python library designed to extract C++ function implementations from source code files using the Clang cindex module.

Features

• Extract functions by name
• Extract functions using regular expressions
• Extract functions by line number

Installation

To use this library, ensure you have Python installed along with the clang library. You can install clang using pip:

pip install clang

Usage

Extract a Function by Name

You can extract a typical C-style function by specifying its name.

from cpp_source_extractor import extract_function_by_name

code = extract_function_by_name("main", "main.cpp")
print(code)

Extract a Function by Line Number

If you have the line number (from a debugger or stack trace) where the function is located, you can extract it using this method. This is recommended as it avoids issues like name mangling.

Note: The line number can be within the body of the function, not necessarily the line where the function is defined.

from cpp_source_extractor import extract_function_by_line_number

code = extract_function_by_line_number(10, "main.cpp")
print(code)

Add semantic information

Extracting functions wrapped in preprocessor directives can be challenging, as shown in the example below:

#ifdef __os_linux__
void foo() {
    // ...
}
#elif __os_macos__
void foo() {
    // ...
}
#endif

Here, the function foo is defined differently based on the operating system configuration. To ensure you extract the correct version of the function, you have two options:

1. Use Compile Arguments: Specify the relevant macro definitions as compile arguments (e.g., -D__os_linux__ or -D__os_macos__) when extracting functions:

code = extract_function_by_name("foo", "main.cpp", extra_args=["-D__os_linux__"])
print(code)

2. Use a Compilation Database: Provide the path to a JSON Compilation Database, which contains the necessary build information:

code = extract_function_by_name("foo", "main.cpp", database="/path/to/compile_commands.json")
print(code)

You can generate a compilation database using CMake:

cmake -DCMAKE_EXPORT_COMPILE_COMMANDS=ON .

Or, for Make-based projects, you can use bear to generate the compilation database.

Contributing

Contributions are welcome! If you have suggestions or improvements, feel free to open an issue or submit a pull request.

License

This project is licensed under the MIT License. See the LICENSE file for details.