Project Structure

• bin - Contains ffigen.dart script which end user will execute.
• tool - Contains script to generate LibClang bindings using Code_Generator submodule (dev use only).
• example - Example projects which demonstrate generation of bindings for given C header files.
• lib/src/code_generator - Generates binding files.
• lib/src/config_provider - Holds configurations to be passed to other modules.
• lib/src/header_parser - Parses header files, utilises clang_bindings.

Basic Workflow

1. The User provides the location all the header files (as a list of globs or filepaths), For each header file, we create a translation unit and parse the declarations in it to the bindings.
2. User can provide header filters to select which declaration from a particular header file should be added to the generated bindings. The can provide a list of header ‘names’ to include/exclude. We compare the header file name (not the exact path) to decide. The default behaviour is to include everything that's included when parsing a header.
3. Use can provide Compiler options, which are passed to clang compiler as it is.
4. All bindings are generated in a single file.

Code Details

Modules

We are using libclang to parse header files. This project is roughly divided in 3 major modules -

code_generator

Converts a library(all bindings) to an actual string representation.

• Library (output of the header parser).
• Writer (provides configurations for generating bindings).
• Binding (base class for all bindings - Func, Struc, Global, EnumClass, etc).

config_provider

This takes care of validating user config files, printing config warnings and errors, converting config.yaml to a format the header_parser can use.

• Spec (represents a single config, which a user can provide in the config file).
• Config (holds all the config which will be required by header parser).

header_parser

Uses libclang to convert the header to a Library which is then used by code_generator.

• clang_bindings (bindings to libclang which are used for parsing).
• sub_parsers (each sub-parser parses a particular kind of declaration - struct, function, typedef, enum).
• type_extractor (extracts types from variables, function parameters, return types).
• includer (tells what should/shouldn't be included depending of config).
• parser (Main Entrypoint) (creates translation units for all header files, and sets up parsing them).
• translation_unit_parser (parses header files, splits declarations and feeds them to their respective sub_parsers).