Compatibility
- 12.2.2 and main5.35.25.15.04.2
- 12.2.2 and mainiOSmacOS(Intel)macOS(ARM)LinuxtvOSwatchOS
A simple GIR parser in Swift for creating Swift types for a .gir file
A simple GIR parser in Swift for creating Swift types for a .gir file
To start a project that uses Swift wrappers around low-level libraries that utilise gobject-introspection, you need to create some scripts that use gir2swift
to convert the information within gobject-introspection XML (.gir
) files into Swift. Here is a brief overview of the basic steps:
gir2swift
(see Building below)gir2swift
(see Usage below) and then builds your project using swift build
awk
or sed
) to correct the errors the compiler complains aboutAs of version 12.2, init(raw:)
is now required by the protocol and init(retainingRaw:)
is required for classes, closing PR#6.
Version 12 pulls in PR#10, addressing several issues:
private=1
-a
option generates all recordsPartially implemented:
Version 11 introduces a new type system into gir2swift
,
to ensure it has a representation of the underlying types.
This is necessary for Swift 5.3 onwards, which requires more stringent casts.
As a consequence, accessors can accept and return idiomatic Swift rather than
underlying types or pointers.
This means that a lot of the changes will be source-breaking for code that
was compiled against libraries built with earlier versions of gir2swift
.
gir
file@inlinable
to enable the compiler to optimise away most of the wrappersRef
wrappers instead of pointers, Int
instead of gint
, etc.)ErrorType
has been renamed GLibError
to ensure it neither clashes with Swift.Error
nor the GLib.ErrorType
scanner enumRef
wrapper instead of the underlying pointergir2swift [-v][-s][-m module_boilerplate.swift]{-p file.gir}[file.gir ...]
gir2swift
takes the information from a gobject-introspection XML (file.gir
) file and creates corresponding Swift wrappers. When reading the .gir
file, gir2swift
also reads a number of Module Files that you create with additional information.
The following options are available:
-m Module.swift
AddModule.swift
as the main (hand-crafted) Swift file for your library target.
-o directory
Specify the output directory to put the generated files into.
-p pre.gir
Addpre.gir
as a pre-requisite.gir
file to ensure the types infile.gir
are known
-s
Create a single.swift
file per class
-v
Produce verbose output.
The following command generates a Swift Wrapper in Sources/GIO
from the information in /usr/share/gir-1.0/Gio-2.0.gir
, copying the content from Gio-2.0.module
and taking into account information in GLib-2.0.gir
and GObject-2.0.gir
:
gir2swift -o Sources/GIO -m Gio-2.0.module -p /usr/share/gir-1.0/GLib-2.0.gir -p /usr/share/gir-1.0/GObject-2.0.gir /usr/share/gir-1.0/Gio-2.0.gir
The Gio-2.0.module
file would need to contain the code that you would want to manually add to your Swift module, for example:
import CGLib
import GLib
import GLibObject
public struct GDatagramBased {}
public struct GUnixConnectionPrivate {}
public struct GUnixCredentialsMessagePrivate {}
public struct GUnixFDListPrivate {}
public struct GUnixFDMessagePrivate {}
public struct GUnixInputStreamPrivate {}
public struct GUnixOutputStreamPrivate {}
public struct GUnixSocketAddressPrivate {}
func g_io_module_load(_ module: UnsafeMutablePointer<GIOModule>) {
fatalError("private g_io_module_load called")
}
func g_io_module_unload(_ module: UnsafeMutablePointer<GIOModule>) {
fatalError("private g_io_module_unload called")
}
Also you would need a corresponding preamble file Gio-2.0.preamble
that imports the necessary low-level libraries, e.g.:
import CGLib
import GLib
import GLibObject
In addition to reading a given Module.gir
file, gir2swift
also reads a number of module files from the current working directory that contain additional information. These module files need to have the same name as the .gir
file, but have a different file extension:
Module.preamble
This file contains the Swift code that you need to as the preamble for every generated .swift
file (e.g. the import
statements for all the modules you want to import).
Module.blacklist
This file contains the symbols (separated by newline) that you want to suppress in your output. Here you should include all the symbols in the .gir
file that the Swift compiler cannot import from the relevant C language headers.
Module.whitelist
This file contains the symbols (separated by newline) that would otherwise be suppressed (e.g. because gir2swift
thinks they are duplicates), but you would like to include in the gir2swift
output.
Module.verbatim
Normally, gir2swift
tries to translate constants from C to Swift, as per the definitions in the .gir
files. Names of constants listed (and separated by newline) in this file will not be translated.
To build, you need at least Swift 5.2 (Swift 5.3 onwards should work fine), download from https://swift.org/download/ -- if you are using macOS, make sure you have the command line tools installed as well). Test that your compiler works using swift --version
, which should give you something like
$ swift --version
Apple Swift version 5.3.2 (swiftlang-1200.0.45 clang-1200.0.32.28)
Target: x86_64-apple-darwin20.3.0
on macOS, or on Linux you should get something like:
$ swift --version
Swift version 5.3.2 (swift-5.3.2-RELEASE)
Target: x86_64-unknown-linux-gnu
These Swift wrappers have been tested with libxml-2.9.4 and 2.9.9. They should work with higher versions, but YMMV. Also make sure you have gobject-introspection
and its .gir
files installed.
On current versions of macOS, you need to install libxml2
using HomeBrew (the version that comes with the system does not include the necessary development headers -- for HomeBrew setup instructions, see http://brew.sh):
brew update
brew install libxml2 gobject-introspection
On Ubuntu 16.04, 18.04 and 20.04, you can use the gtk that comes with the distribution. Just install with the apt
package manager:
sudo apt update
sudo apt install libxml2-dev gobject-introspection libgirepository1.0-dev
On Fedora 29, you can use the gtk that comes with the distribution. Just install with the dnf
package manager:
sudo dnf install libxml2-devel gobject-introspection-devel
Normally, you don't build this package directly, but you embed it into your own project (see 'Embedding' below). However, you can build and test this module separately to ensure that everything works. Make sure you have all the prerequisites installed (see above). After that, you can simply clone this repository and build the command line executable (be patient, this will download all the required dependencies and take a while to compile) using
git clone https://github.com/rhx/gir2swift.git
cd gir2swift
./build.sh
On macOS, you can build the project using Xcode instead. To do this, you need to create an Xcode project first, then open the project in the Xcode IDE:
./xcodegen.sh
open gir2swift.xcodeproj
After that, use the (usual) Build and Test buttons to build/test this package.
Here are some common errors you might encounter and how to fix them.
If you get an error such as
$ ./build.sh
error: unable to invoke subcommand: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/swift-package (No such file or directory)
this probably means that your Swift toolchain is too old. Make sure the latest toolchain is the one that is found when you run the Swift compiler (see above).
If you get an older version, make sure that the right version of the swift compiler is found first in your PATH
. On macOS, use xcode-select to select and install the latest version, e.g.:
sudo xcode-select -s /Applications/Xcode.app
xcode-select --install
My Drive
directory used by Google Drive File Stream). As a workaround, use the old build scripts, e.g. ./build.sh
instead of run-gir2swift.sh
and swift build
to build a package.