1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
|
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<!-- Copyright (C) 1999-2023 Free Software Foundation, Inc.
Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.3 or
any later version published by the Free Software Foundation; with the
Invariant Sections being "Funding Free Software", the Front-Cover
Texts being (a) (see below), and with the Back-Cover Texts being (b)
(see below). A copy of the license is included in the section entitled
"GNU Free Documentation License".
(a) The FSF's Front-Cover Text is:
A GNU Manual
(b) The FSF's Back-Cover Text is:
You have freedom to copy and modify this GNU Manual, like GNU
software. Copies published by the Free Software Foundation raise
funds for GNU development. -->
<!-- Created by GNU Texinfo 5.1, http://www.gnu.org/software/texinfo/ -->
<head>
<title>The GNU Fortran Compiler: Interoperability Options</title>
<meta name="description" content="The GNU Fortran Compiler: Interoperability Options">
<meta name="keywords" content="The GNU Fortran Compiler: Interoperability Options">
<meta name="resource-type" content="document">
<meta name="distribution" content="global">
<meta name="Generator" content="makeinfo">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<link href="index.html#Top" rel="start" title="Top">
<link href="Option-Index.html#Option-Index" rel="index" title="Option Index">
<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
<link href="Invoking-GNU-Fortran.html#Invoking-GNU-Fortran" rel="up" title="Invoking GNU Fortran">
<link href="Environment-Variables.html#Environment-Variables" rel="next" title="Environment Variables">
<link href="Code-Gen-Options.html#Code-Gen-Options" rel="previous" title="Code Gen Options">
<style type="text/css">
<!--
a.summary-letter {text-decoration: none}
blockquote.smallquotation {font-size: smaller}
div.display {margin-left: 3.2em}
div.example {margin-left: 3.2em}
div.indentedblock {margin-left: 3.2em}
div.lisp {margin-left: 3.2em}
div.smalldisplay {margin-left: 3.2em}
div.smallexample {margin-left: 3.2em}
div.smallindentedblock {margin-left: 3.2em; font-size: smaller}
div.smalllisp {margin-left: 3.2em}
kbd {font-style:oblique}
pre.display {font-family: inherit}
pre.format {font-family: inherit}
pre.menu-comment {font-family: serif}
pre.menu-preformatted {font-family: serif}
pre.smalldisplay {font-family: inherit; font-size: smaller}
pre.smallexample {font-size: smaller}
pre.smallformat {font-family: inherit; font-size: smaller}
pre.smalllisp {font-size: smaller}
span.nocodebreak {white-space:nowrap}
span.nolinebreak {white-space:nowrap}
span.roman {font-family:serif; font-weight:normal}
span.sansserif {font-family:sans-serif; font-weight:normal}
ul.no-bullet {list-style: none}
-->
</style>
</head>
<body lang="en" bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#800080" alink="#FF0000">
<a name="Interoperability-Options"></a>
<div class="header">
<p>
Next: <a href="Environment-Variables.html#Environment-Variables" accesskey="n" rel="next">Environment Variables</a>, Previous: <a href="Code-Gen-Options.html#Code-Gen-Options" accesskey="p" rel="previous">Code Gen Options</a>, Up: <a href="Invoking-GNU-Fortran.html#Invoking-GNU-Fortran" accesskey="u" rel="up">Invoking GNU Fortran</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Option-Index.html#Option-Index" title="Index" rel="index">Index</a>]</p>
</div>
<hr>
<a name="Options-for-interoperability-with-other-languages"></a>
<h3 class="section">2.10 Options for interoperability with other languages</h3>
<dl compact="compact">
<dd>
<a name="index-c_002dprototypes"></a>
<a name="index-Generating-C-prototypes-from-Fortran-BIND_0028C_0029-enteties"></a>
</dd>
<dt>-fc-prototypes</dt>
<dd><p>This option will generate C prototypes from <code>BIND(C)</code> variable
declarations, types and procedure interfaces and writes them to
standard output. <code>ENUM</code> is not yet supported.
</p>
<p>The generated prototypes may need inclusion of an appropriate header,
such as <code><stdint.h></code> or <code><stdlib.h></code>. For types which are
not specified using the appropriate kind from the <code>iso_c_binding</code>
module, a warning is added as a comment to the code.
</p>
<p>For function pointers, a pointer to a function returning <code>int</code>
without an explicit argument list is generated.
</p>
<p>Example of use:
</p><div class="smallexample">
<pre class="smallexample">$ gfortran -fc-prototypes -fsyntax-only foo.f90 > foo.h
</pre></div>
<p>where the C code intended for interoperating with the Fortran code
then uses <code>#include "foo.h"</code>.
</p>
<a name="index-c_002dprototypes_002dexternal"></a>
<a name="index-Generating-C-prototypes-from-external-procedures"></a>
</dd>
<dt>-fc-prototypes-external</dt>
<dd><p>This option will generate C prototypes from external functions and
subroutines and write them to standard output. This may be useful for
making sure that C bindings to Fortran code are correct. This option
does not generate prototypes for <code>BIND(C)</code> procedures, use
<samp>-fc-prototypes</samp> for that.
</p>
<p>The generated prototypes may need inclusion of an appropriate
header, such as <code><stdint.h></code> or <code><stdlib.h></code>.
</p>
<p>This is primarily meant for legacy code to ensure that existing C
bindings match what <code>gfortran</code> emits. The generated C
prototypes should be correct for the current version of the compiler,
but may not match what other compilers or earlier versions of
<code>gfortran</code> need. For new developments, use of the
<code>BIND(C)</code> features is recommended.
</p>
<p>Example of use:
</p><div class="smallexample">
<pre class="smallexample">$ gfortran -fc-prototypes-external -fsyntax-only foo.f > foo.h
</pre></div>
<p>where the C code intended for interoperating with the Fortran code
then uses <code>#include "foo.h"</code>.
</p></dd>
</dl>
<hr>
<div class="header">
<p>
Next: <a href="Environment-Variables.html#Environment-Variables" accesskey="n" rel="next">Environment Variables</a>, Previous: <a href="Code-Gen-Options.html#Code-Gen-Options" accesskey="p" rel="previous">Code Gen Options</a>, Up: <a href="Invoking-GNU-Fortran.html#Invoking-GNU-Fortran" accesskey="u" rel="up">Invoking GNU Fortran</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Option-Index.html#Option-Index" title="Index" rel="index">Index</a>]</p>
</div>
</body>
</html>
|
