| <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> |
| <html> |
| <!-- Copyright (C) 1999-2014 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 5.2, http://www.gnu.org/software/texinfo/ --> |
| <head> |
| <title>The GNU Fortran Compiler: Non-Fortran Main Program</title> |
| |
| <meta name="description" content="The GNU Fortran Compiler: Non-Fortran Main Program"> |
| <meta name="keywords" content="The GNU Fortran Compiler: Non-Fortran Main Program"> |
| <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="Mixed_002dLanguage-Programming.html#Mixed_002dLanguage-Programming" rel="up" title="Mixed-Language Programming"> |
| <link href="_005fgfortran_005fset_005fargs.html#g_t_005fgfortran_005fset_005fargs" rel="next" title="_gfortran_set_args"> |
| <link href="GNU-Fortran-Compiler-Directives.html#GNU-Fortran-Compiler-Directives" rel="prev" title="GNU Fortran Compiler Directives"> |
| <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="Non_002dFortran-Main-Program"></a> |
| <div class="header"> |
| <p> |
| Next: <a href="Naming-and-argument_002dpassing-conventions.html#Naming-and-argument_002dpassing-conventions" accesskey="n" rel="next">Naming and argument-passing conventions</a>, Previous: <a href="GNU-Fortran-Compiler-Directives.html#GNU-Fortran-Compiler-Directives" accesskey="p" rel="prev">GNU Fortran Compiler Directives</a>, Up: <a href="Mixed_002dLanguage-Programming.html#Mixed_002dLanguage-Programming" accesskey="u" rel="up">Mixed-Language Programming</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="Non_002dFortran-Main-Program-1"></a> |
| <h3 class="section">7.3 Non-Fortran Main Program</h3> |
| |
| <table class="menu" border="0" cellspacing="0"> |
| <tr><td align="left" valign="top">• <a href="_005fgfortran_005fset_005fargs.html#g_t_005fgfortran_005fset_005fargs" accesskey="1">_gfortran_set_args</a>:</td><td> </td><td align="left" valign="top">Save command-line arguments |
| </td></tr> |
| <tr><td align="left" valign="top">• <a href="_005fgfortran_005fset_005foptions.html#g_t_005fgfortran_005fset_005foptions" accesskey="2">_gfortran_set_options</a>:</td><td> </td><td align="left" valign="top">Set library option flags |
| </td></tr> |
| <tr><td align="left" valign="top">• <a href="_005fgfortran_005fset_005fconvert.html#g_t_005fgfortran_005fset_005fconvert" accesskey="3">_gfortran_set_convert</a>:</td><td> </td><td align="left" valign="top">Set endian conversion |
| </td></tr> |
| <tr><td align="left" valign="top">• <a href="_005fgfortran_005fset_005frecord_005fmarker.html#g_t_005fgfortran_005fset_005frecord_005fmarker" accesskey="4">_gfortran_set_record_marker</a>:</td><td> </td><td align="left" valign="top">Set length of record markers |
| </td></tr> |
| <tr><td align="left" valign="top">• <a href="_005fgfortran_005fset_005ffpe.html#g_t_005fgfortran_005fset_005ffpe" accesskey="5">_gfortran_set_fpe</a>:</td><td> </td><td align="left" valign="top">Set when a Floating Point Exception should be raised |
| </td></tr> |
| <tr><td align="left" valign="top">• <a href="_005fgfortran_005fset_005fmax_005fsubrecord_005flength.html#g_t_005fgfortran_005fset_005fmax_005fsubrecord_005flength" accesskey="6">_gfortran_set_max_subrecord_length</a>:</td><td> </td><td align="left" valign="top">Set subrecord length |
| </td></tr> |
| </table> |
| |
| <p>Even if you are doing mixed-language programming, it is very |
| likely that you do not need to know or use the information in this |
| section. Since it is about the internal structure of GNU Fortran, |
| it may also change in GCC minor releases. |
| </p> |
| <p>When you compile a <code>PROGRAM</code> with GNU Fortran, a function |
| with the name <code>main</code> (in the symbol table of the object file) |
| is generated, which initializes the libgfortran library and then |
| calls the actual program which uses the name <code>MAIN__</code>, for |
| historic reasons. If you link GNU Fortran compiled procedures |
| to, e.g., a C or C++ program or to a Fortran program compiled by |
| a different compiler, the libgfortran library is not initialized |
| and thus a few intrinsic procedures do not work properly, e.g. |
| those for obtaining the command-line arguments. |
| </p> |
| <p>Therefore, if your <code>PROGRAM</code> is not compiled with |
| GNU Fortran and the GNU Fortran compiled procedures require |
| intrinsics relying on the library initialization, you need to |
| initialize the library yourself. Using the default options, |
| gfortran calls <code>_gfortran_set_args</code> and |
| <code>_gfortran_set_options</code>. The initialization of the former |
| is needed if the called procedures access the command line |
| (and for backtracing); the latter sets some flags based on the |
| standard chosen or to enable backtracing. In typical programs, |
| it is not necessary to call any initialization function. |
| </p> |
| <p>If your <code>PROGRAM</code> is compiled with GNU Fortran, you shall |
| not call any of the following functions. The libgfortran |
| initialization functions are shown in C syntax but using C |
| bindings they are also accessible from Fortran. |
| </p> |
| |
| <hr> |
| <div class="header"> |
| <p> |
| Next: <a href="Naming-and-argument_002dpassing-conventions.html#Naming-and-argument_002dpassing-conventions" accesskey="n" rel="next">Naming and argument-passing conventions</a>, Previous: <a href="GNU-Fortran-Compiler-Directives.html#GNU-Fortran-Compiler-Directives" accesskey="p" rel="prev">GNU Fortran Compiler Directives</a>, Up: <a href="Mixed_002dLanguage-Programming.html#Mixed_002dLanguage-Programming" accesskey="u" rel="up">Mixed-Language Programming</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> |
