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diff --git a/share/doc/gfortran/Interoperable-Global-Variables.html b/share/doc/gfortran/Interoperable-Global-Variables.html new file mode 100644 index 0000000..162b4ee --- /dev/null +++ b/share/doc/gfortran/Interoperable-Global-Variables.html @@ -0,0 +1,111 @@ +<!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). 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Those variables +have to be declared in the declaration part of a <code>MODULE</code>, +be of interoperable type, and have neither the <code>pointer</code> nor +the <code>allocatable</code> attribute. +</p> +<div class="smallexample"> +<pre class="smallexample"> MODULE m + USE myType_module + USE ISO_C_BINDING + integer(C_INT), bind(C, name="_MyProject_flags") :: global_flag + type(myType), bind(C) :: tp + END MODULE +</pre></div> + +<p>Here, <code>_MyProject_flags</code> is the case-sensitive name of the variable +as seen from C programs while <code>global_flag</code> is the case-insensitive +name as seen from Fortran. If no binding name is specified, as for +<var>tp</var>, the C binding name is the (lowercase) Fortran binding name. +If a binding name is specified, only a single variable may be after the +double colon. Note of warning: You cannot use a global variable to +access <var>errno</var> of the C library as the C standard allows it to be +a macro. Use the <code>IERRNO</code> intrinsic (GNU extension) instead. +</p> + + + +</body> +</html> |