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    0.0.8 • Public • Published

    npm install -g ffi-generate

    Generate FFI Bindings

    ffi-generate -f /path/to/myLibrary/header.h -l libmyLibrary

    Will parse the given filename and print to standard out the resulting javascript suitable for use as a module.

    • f -- required -- The header file you wish to parse
    • l -- required -- The library FFI will use to dlopen
    • m -- optional -- The module name underwhich functions will be stored (uses library name otherwise)
    • p -- optional -- Only include functions whose name starts with the provided prefix
    • you can specify multiple -p on the command line to get multiple prefixes
    • x -- optional -- Restrict to only functions declared in the given header file
    • s -- optional -- Use StrictType type wrapper (experimental)
    • L -- optional -- If libclang.{so,dylib} is in a non-standard path use this which will rerun the process with [DY]LD_LIBRARY_PATH set

    It may be necessary to pass additional flags to libclang so it can better parse the header (i.e. include paths). To pass options directly to libclang use -- so ffi-generate-node knows to stop parsing arguments, the rest will be passed to libclang without modification.

    ffi-generate -f /usr/include/ImageMagick/wand/MagickWand.h -l libMagickWand -m wand -p Magick -- $(Magick-config --cflags)

    Generate FFI Bindings Programatically

    var exec = require('child_process').exec;
    var path = require('path');
    var fs = require('fs');
    var jsb = require('beautifyjs');
    var generate = require('lib/generateffi').generate;
    exec('llvm-config --includedir', function (fail, out, err) {
      var includedir = out.replace(/\s+$/, '');
      var result = exports.generate({
        filename: path.join(includedir, 'clang-c', 'Index.h'),
        library: 'libclang',
        prefix: 'clang_', 
        includes: [includedir],
      if (result.unmapped.length > 0) {
        console.log('----- UNMAPPED FUNCTIONS -----');
        console.log('----- UNMAPPED FUNCTIONS -----');
      fs.writeFileSync(path.join(__dirname, 'dynamic_clang.js'), jsb.js_beautify(result.serialized));
      var dynamic_clang = require(path.join(__dirname, 'dynamic_clang'));
      var ver = dynamic_clang.libclang.clang_getClangVersion();

    Input to the generate method

    • opts.filename -- required -- the full path to the header source file to parse
    • opts.library -- required -- the library ffi should use to dlopen
    • opts.module -- optional -- the name of the module that will be exported (otherwise uses library name)
    • opts.prefix -- optional -- restrict imported functions to a given prefix
    • opts.includes -- optional -- a set of directory paths to aid type expansion
    • opts.compiler_args -- optional -- a set of clang command line options passed to the parser
    • opts.single_file -- optional -- restricts functions to only those defined in the header file
      • this does not restrict dependent types

    The result from generate is an object that has two properties

    • serialized - a string representation of the bindings suitable for writing to file
    • unmapped - a set of functions that failed to map -- most likely from failure to map a type to ffi type.
    • each element is an object with following properties
    • position - -1 means the return type, otherwise the argument
    • arg - name of the type that failed to map
    • name - the name of the function that failed
    • decl - the signature of the function that failed




    npm i ffi-generate

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    • tjfontaine