I can not for the life of me get even the simplest C extension example
to load into ruby on Windows XP. The first case I tried actually was
the example provided by SWIG (the simple example). It fails with the
message
runme.rb:3:in `require’: 127: The specified procedure could not be
found. - In
it_Example (LoadError)
./Example.dll
from runme.rb:3
The example was compiled with the provided MS-VC++ 6 project without
error. A dumpbin of example.dll reveals that the symbol Init_Example is
in fact exported. The same error is reported in both ruby 1.6.8 and
ruby 1.8.2. This is supposed to work in theory since it’s
‘automatically’ generated by SWIG
I then tried to generate my own example based on some tutorials.
//--------------------simple.c------------------------------------------------
#include “ruby.h”
static VALUE simple_initialize(VALUE self, int iValue)
{
rb_iv_set(self,"@i",iValue);
rb_iv_set(self,"@a",rb_ary_new());
return self;
}
static VALUE simple_get_i(VALUE self)
{
return rb_iv_get(self,"@i");
}
static VALUE simple_set_i(VALUE self, int iValue)
{
return rb_iv_set(self,"@i",iValue);
}
static VALUE simple_get_a(VALUE self)
{
return rb_iv_get(self,"@a");
}
VALUE csimple;
void Init_simple()
{
csimple = rb_define_class(“simple”,rb_cObject);
rb_define_method(csimple,“initialize”,simple_initialize,1);
rb_define_method(csimple,“i”, simple_get_i, 0);
rb_define_method(csimple,“i=”, simple_set_i, 1);
rb_define_method(csimple,“a”, simple_get_a, 0);
}
//---------------------------------------------------------------------
#----- simple.rb ------------
require “simple”
s = simple.new(123)
p s.i
p s.a
s.i = 456
s.a.push(“Hello”)
s.a.push(“World”)
p s.a
#-----------------------------
The compile procedure from MS-VC++ 6
cl /LD /I$(RUBY_INCLUDE) /O2 simple.c $(RUBY_LIBPATH)$(RUBY_LIB) /link
/def:simple.def
which compiles without error or warning. dumpbin reveals that
Dump of file simple.dll
File Type: DLL
Section contains the following exports for simple.dll
0 characteristics
43FE269D time date stamp Thu Feb 23 16:18:21 2006
0.00 version
1 ordinal base
1 number of functions
1 number of names
ordinal hint RVA name
1 0 00001000 Init_simple
Summary
4000 .data
1000 .rdata
1000 .reloc
5000 .text
However running
D:\ruby>ruby simple.rb
./simple.rb:4: undefined local variable or method simple' for #<Object:0x5b6961 8> (NameError) from simple.rb:2:inrequire’
from simple.rb:2
This is the result from running ruby 1.6.8
I might go back and try 1.8.2 again later, but for now I’ll use python.
At least SWIG seems to work with it on windows.