[OpenSPARC-T2-DV] / tools / src / nas,5.n2.os.2 / lib / python / html / swig / Pike.html

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<H1><a name="Pike"></a>25 SWIG and Pike</H1>
<!-- INDEX -->
<div class="sectiontoc">
<ul>
<li><a href="#Pike_nn2">Preliminaries</a>
<ul>
<li><a href="#Pike_nn3">Running SWIG</a>
<li><a href="#Pike_nn4">Getting the right header files</a>
<li><a href="#Pike_nn5">Using your module</a>
</ul>
<li><a href="#Pike_nn6">Basic C/C++ Mapping</a>
<ul>
<li><a href="#Pike_nn7">Modules</a>
<li><a href="#Pike_nn8">Functions</a>
<li><a href="#Pike_nn9">Global variables</a>
<li><a href="#Pike_nn10">Constants and enumerated types</a>
<li><a href="#Pike_nn11">Constructors and Destructors</a>
<li><a href="#Pike_nn12">Static Members</a>
</ul>
</ul>
</div>
<!-- INDEX -->


<p>
This chapter describes SWIG support for Pike. As of this writing, the
SWIG  Pike module is still under development and is not considered
ready for prime  time. The Pike module is being developed against the
Pike 7.4.10 release  and may not be compatible with previous versions
of Pike.
</p>

<p>
This chapter covers most SWIG features, but certain low-level details
are  covered in less depth than in earlier chapters.  At the very
least, make sure you read the "<a href="SWIG.html#SWIG">SWIG Basics</a>"
chapter.<br>
</p>

<H2><a name="Pike_nn2"></a>25.1 Preliminaries</H2>


<H3><a name="Pike_nn3"></a>25.1.1 Running SWIG</H3>


<p>
Suppose that you defined a SWIG module such as the following:
</p>

<div class="code">
  <pre>%module example<br><br>%{<br>#include "example.h"<br>%}<br><br>int fact(int n);<br></pre>
</div>

<p>
To build a C extension module for Pike, run SWIG using the <tt>-pike</tt> option :
</p>

<div class="code">
  <pre>$ <b>swig -pike example.i</b><br></pre>
</div>

<p>
If you're building a C++ extension, be sure to add the <tt>-c++</tt> option:
</p>

<div class="code">
  <pre>$ <b>swig -c++ -pike example.i</b><br></pre>
</div>

<p>
This creates a single source file named <tt>example_wrap.c</tt> (or <tt>example_wrap.cxx</tt>, if you
ran SWIG with the <tt>-c++</tt> option).
The SWIG-generated source file contains the low-level wrappers that need
to be compiled and linked with the rest of your C/C++ application to
create an extension module.
</p>

<p>
The name of the wrapper file is derived from the name of the input
file.  For example, if the input file is <tt>example.i</tt>, the name
of the wrapper file is <tt>example_wrap.c</tt>. To change this, you
can use the <tt>-o</tt> option:
</p>

<div class="code">
  <pre>$ <b>swig -pike -o pseudonym.c example.i</b><br></pre>
</div>
<H3><a name="Pike_nn4"></a>25.1.2 Getting the right header files</H3>


<p>
In order to compile the C/C++ wrappers, the compiler needs to know the
path to the Pike header files. These files are usually contained in a
directory such as
</p>

<div class="code">
  <pre>/usr/local/pike/7.4.10/include/pike<br></pre>
</div>

<p>
There doesn't seem to be any way to get Pike itself to reveal the
location of these files, so you may need to hunt around for them.
You're looking for files with the names <tt>global.h</tt>, <tt>program.h</tt>
and so on.
</p>

<H3><a name="Pike_nn5"></a>25.1.3 Using your module</H3>


<p>
To use your module, simply use Pike's <tt>import</tt> statement:
</p>

<div class="code"><pre>
$ <b>pike</b>
Pike v7.4 release 10 running Hilfe v3.5 (Incremental Pike Frontend)
&gt; <b>import example;</b>
&gt; <b>fact(4);</b>
(1) Result: 24
</pre></div>

<H2><a name="Pike_nn6"></a>25.2 Basic C/C++ Mapping</H2>


<H3><a name="Pike_nn7"></a>25.2.1 Modules</H3>


<p>
All of the code for a given SWIG module is wrapped into a single Pike
module. Since the name of the shared library that implements your
module ultimately determines the module's name (as far as Pike is
concerned), SWIG's <tt>%module</tt> directive doesn't really have any
significance.
</p>

<H3><a name="Pike_nn8"></a>25.2.2 Functions</H3>


<p>
Global functions are wrapped as new Pike built-in functions. For
example,
</p>

<div class="code"><pre>
%module example

int fact(int n);
</pre></div>

<p>
creates a new built-in function <tt>example.fact(n)</tt> that works
exactly as you'd expect it to:
</p>

<div class="code"><pre>
&gt; <b>import example;</b>
&gt; <b>fact(4);</b>
(1) Result: 24
</pre></div>

<H3><a name="Pike_nn9"></a>25.2.3 Global variables</H3>


<p>
Global variables are currently wrapped as a pair of of functions, one to get
the current value of the variable and another to set it. For example, the
declaration
</p>

<div class="code"><pre>
%module example

double Foo;
</pre></div>

<p>
will result in two functions, <tt>Foo_get()</tt> and <tt>Foo_set()</tt>:
</p>

<div class="code"><pre>
&gt; <b>import example;</b>
&gt; <b>Foo_get();</b>
(1) Result: 3.000000
&gt; <b>Foo_set(3.14159);</b>
(2) Result: 0
&gt; <b>Foo_get();</b>
(3) Result: 3.141590
</pre></div>

<H3><a name="Pike_nn10"></a>25.2.4 Constants and enumerated types</H3>


<p>
Enumerated types in C/C++ declarations are wrapped as Pike constants,
not as Pike enums.
</p>

<H3><a name="Pike_nn11"></a>25.2.5 Constructors and Destructors</H3>


<p>
Constructors are wrapped as <tt>create()</tt> methods, and destructors are
wrapped as <tt>destroy()</tt> methods, for Pike classes.
</p>

<H3><a name="Pike_nn12"></a>25.2.6 Static Members</H3>


<p>
Since Pike doesn't support static methods or data for Pike classes, static
member functions in your C++ classes are wrapped as regular functions and
static member variables are wrapped as pairs of functions (one to get the
value of the static member variable, and another to set it). The names of
these functions are prepended with the name of the class.
For example, given this C++ class declaration:
</p>

<div class="code"><pre>
class Shape
{
public:
    static void print();
    static int nshapes;
};
</pre></div>

<p>
SWIG will generate a <tt>Shape_print()</tt> method that invokes the static
<tt>Shape::print()</tt> member function, as well as a pair of methods,
<tt>Shape_nshapes_get()</tt> and <tt>Shape_nshapes_set()</tt>, to get and set
the value of <tt>Shape::nshapes</tt>.
</p>

</body>
</html>
Commit	Line	Data
86530b38 AT	1	<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
	2	<html>
	3	<head>
	4	<title>SWIG and Pike</title>
	5	<link rel="stylesheet" type="text/css" href="style.css">
	6	</head>
	7
	8	<body bgcolor="#ffffff">
	9	<H1><a name="Pike"></a>25 SWIG and Pike</H1>
	10	<!-- INDEX -->
	11	<div class="sectiontoc">
	12	<ul>
	13	<li><a href="#Pike_nn2">Preliminaries</a>
	14	<ul>
	15	<li><a href="#Pike_nn3">Running SWIG</a>
	16	<li><a href="#Pike_nn4">Getting the right header files</a>
	17	<li><a href="#Pike_nn5">Using your module</a>
	18	</ul>
	19	<li><a href="#Pike_nn6">Basic C/C++ Mapping</a>
	20	<ul>
	21	<li><a href="#Pike_nn7">Modules</a>
	22	<li><a href="#Pike_nn8">Functions</a>
	23	<li><a href="#Pike_nn9">Global variables</a>
	24	<li><a href="#Pike_nn10">Constants and enumerated types</a>
	25	<li><a href="#Pike_nn11">Constructors and Destructors</a>
	26	<li><a href="#Pike_nn12">Static Members</a>
	27	</ul>
	28	</ul>
	29	</div>
	30	<!-- INDEX -->
	31
	32
	33
	34	<p>
	35	This chapter describes SWIG support for Pike. As of this writing, the
	36	SWIG Pike module is still under development and is not considered
	37	ready for prime time. The Pike module is being developed against the
	38	Pike 7.4.10 release and may not be compatible with previous versions
	39	of Pike.
	40	</p>
	41
	42	<p>
	43	This chapter covers most SWIG features, but certain low-level details
	44	are covered in less depth than in earlier chapters. At the very
	45	least, make sure you read the "<a href="SWIG.html#SWIG">SWIG Basics</a>"
	46	chapter.<br>
	47	</p>
	48
	49	<H2><a name="Pike_nn2"></a>25.1 Preliminaries</H2>
	50
	51
	52	<H3><a name="Pike_nn3"></a>25.1.1 Running SWIG</H3>
	53
	54
	55	<p>
	56	Suppose that you defined a SWIG module such as the following:
	57	</p>
	58
	59	<div class="code">
	60	<pre>%module example<br><br>%{<br>#include "example.h"<br>%}<br><br>int fact(int n);<br></pre>
	61	</div>
	62
	63	<p>
	64	To build a C extension module for Pike, run SWIG using the <tt>-pike</tt> option :
65	</p>
66
67	<div class="code">
68	<pre>$ <b>swig -pike example.i</b><br></pre>
69	</div>
70
71	<p>
72	If you're building a C++ extension, be sure to add the <tt>-c++</tt> option:
73	</p>
74
75	<div class="code">
76	<pre>$ <b>swig -c++ -pike example.i</b><br></pre>
77	</div>
78
79	<p>
80	This creates a single source file named <tt>example_wrap.c</tt> (or <tt>example_wrap.cxx</tt>, if you
81	ran SWIG with the <tt>-c++</tt> option).
82	The SWIG-generated source file contains the low-level wrappers that need
83	to be compiled and linked with the rest of your C/C++ application to
84	create an extension module.
85	</p>
86
87	<p>
88	The name of the wrapper file is derived from the name of the input
89	file. For example, if the input file is <tt>example.i</tt>, the name
90	of the wrapper file is <tt>example_wrap.c</tt>. To change this, you
91	can use the <tt>-o</tt> option:
92	</p>
93
94	<div class="code">
95	<pre>$ <b>swig -pike -o pseudonym.c example.i</b><br></pre>
96	</div>
97	<H3><a name="Pike_nn4"></a>25.1.2 Getting the right header files</H3>
98
99
100	<p>
101	In order to compile the C/C++ wrappers, the compiler needs to know the
102	path to the Pike header files. These files are usually contained in a
103	directory such as
104	</p>
105
106	<div class="code">
107	<pre>/usr/local/pike/7.4.10/include/pike<br></pre>
108	</div>
109
110	<p>
111	There doesn't seem to be any way to get Pike itself to reveal the
112	location of these files, so you may need to hunt around for them.
113	You're looking for files with the names <tt>global.h</tt>, <tt>program.h</tt>
114	and so on.
115	</p>
116
117	<H3><a name="Pike_nn5"></a>25.1.3 Using your module</H3>
118
119
120	<p>
121	To use your module, simply use Pike's <tt>import</tt> statement:
122	</p>
123
124	<div class="code"><pre>
125	$ <b>pike</b>
126	Pike v7.4 release 10 running Hilfe v3.5 (Incremental Pike Frontend)
127	> <b>import example;</b>
128	> <b>fact(4);</b>
129	(1) Result: 24
130	</pre></div>
131
132	<H2><a name="Pike_nn6"></a>25.2 Basic C/C++ Mapping</H2>
133
134
135	<H3><a name="Pike_nn7"></a>25.2.1 Modules</H3>
136
137
138	<p>
139	All of the code for a given SWIG module is wrapped into a single Pike
140	module. Since the name of the shared library that implements your
141	module ultimately determines the module's name (as far as Pike is
142	concerned), SWIG's <tt>%module</tt> directive doesn't really have any
143	significance.
144	</p>
145
146	<H3><a name="Pike_nn8"></a>25.2.2 Functions</H3>
147
148
149	<p>
150	Global functions are wrapped as new Pike built-in functions. For
151	example,
152	</p>
153
154	<div class="code"><pre>
155	%module example
156
157	int fact(int n);
158	</pre></div>
159
160	<p>
161	creates a new built-in function <tt>example.fact(n)</tt> that works
162	exactly as you'd expect it to:
163	</p>
164
165	<div class="code"><pre>
166	> <b>import example;</b>
167	> <b>fact(4);</b>
168	(1) Result: 24
169	</pre></div>
170
171	<H3><a name="Pike_nn9"></a>25.2.3 Global variables</H3>
172
173
174	<p>
175	Global variables are currently wrapped as a pair of of functions, one to get
176	the current value of the variable and another to set it. For example, the
177	declaration
178	</p>
179
180	<div class="code"><pre>
181	%module example
182
183	double Foo;
184	</pre></div>
185
186	<p>
187	will result in two functions, <tt>Foo_get()</tt> and <tt>Foo_set()</tt>:
188	</p>
189
190	<div class="code"><pre>
191	> <b>import example;</b>
192	> <b>Foo_get();</b>
193	(1) Result: 3.000000
194	> <b>Foo_set(3.14159);</b>
195	(2) Result: 0
196	> <b>Foo_get();</b>
197	(3) Result: 3.141590
198	</pre></div>
199
200	<H3><a name="Pike_nn10"></a>25.2.4 Constants and enumerated types</H3>
201
202
203	<p>
204	Enumerated types in C/C++ declarations are wrapped as Pike constants,
205	not as Pike enums.
206	</p>
207
208	<H3><a name="Pike_nn11"></a>25.2.5 Constructors and Destructors</H3>
209
210
211	<p>
212	Constructors are wrapped as <tt>create()</tt> methods, and destructors are
213	wrapped as <tt>destroy()</tt> methods, for Pike classes.
214	</p>
215
216	<H3><a name="Pike_nn12"></a>25.2.6 Static Members</H3>
217
218
219	<p>
220	Since Pike doesn't support static methods or data for Pike classes, static
221	member functions in your C++ classes are wrapped as regular functions and
222	static member variables are wrapped as pairs of functions (one to get the
223	value of the static member variable, and another to set it). The names of
224	these functions are prepended with the name of the class.
225	For example, given this C++ class declaration:
226	</p>
227
228	<div class="code"><pre>
229	class Shape
230	{
231	public:
232	static void print();
233	static int nshapes;
234	};
235	</pre></div>
236
237	<p>
238	SWIG will generate a <tt>Shape_print()</tt> method that invokes the static
239	<tt>Shape::print()</tt> member function, as well as a pair of methods,
240	<tt>Shape_nshapes_get()</tt> and <tt>Shape_nshapes_set()</tt>, to get and set
241	the value of <tt>Shape::nshapes</tt>.
242	</p>
243
244	</body>
245	</html>