SWIG Go Examples

The following examples illustrate the use of SWIG with Go.

• simple. A minimal example showing how SWIG can be used to wrap a C function, a global variable, and a constant.
• constants. This shows how preprocessor macros and certain C declarations are turned into constants.
• variables. An example showing how to access C global variables from Go.
• enum. Wrapping enumerations.
• class. Wrapping a simple C++ class.
• reference. C++ references.
• pointer. Simple pointer handling.
• funcptr. Pointers to functions.
• template. C++ templates.
• callback. C++ callbacks using directors.
• extend. Polymorphism using directors.
• director. Example how to utilize the director feature.
• director. Example how to use goin and godirectorin.

Compilation Issues

• To create a Go extension, SWIG is run with the following options:

  % swig -go interface.i
  

• On Unix the compilation of examples is done using the file Example/Makefile. Normally builds are done simply using go build. For testing purposes this makefile performs a manual module compilation that is platform specific. When using the gc compiler, the steps look approximately like this (GNU/Linux):

  % swig -go -cgo interface.i
  % mkdir -p gopath/src/interface
  % cp interface_wrap.c interface_wrap.h interface.go gopath/src/interface
  % GOPATH=`pwd`/gopath
  % export GOPATH
  % cd gopath/src/interface
  % go build
  % go tool compile $(SRCDIR)/runme.go
  % go tool link -o runme runme.o
  

• When using the gccgo compiler, the steps look like this:

  % swig -go -cgo interface.i
  % mkdir -p gopath/src/interface
  % cp interface_wrap.c interface_wrap.h interface.go gopath/src/interface
  % GOPATH=`pwd`/gopath
  % export GOPATH
  % cd gopath/src/interface
  % go build
  % gccgo -c $(SRCDIR)/runme.go
  % gccgo -o runme runme.o interface.a
  

  Compatibility

  The examples have been extensively tested on the following platforms:
  • GNU/Linux
  All of the examples were last tested with the following configuration (5 August 2015):
  • Ubuntu Trusty
  • gcc-4.8.4
  Your mileage may vary. If you experience a problem, please let us know by contacting us on the mailing lists.