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143 lines
9.0 KiB
HTML
143 lines
9.0 KiB
HTML
4 years ago
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<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
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<html>
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<!-- Copyright (C) 1988-2018 Free Software Foundation, Inc.
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Permission is granted to copy, distribute and/or modify this document
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under the terms of the GNU Free Documentation License, Version 1.3 or
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any later version published by the Free Software Foundation; with the
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Invariant Sections being "Funding Free Software", the Front-Cover
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Texts being (a) (see below), and with the Back-Cover Texts being (b)
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(see below). A copy of the license is included in the section entitled
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"GNU Free Documentation License".
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(a) The FSF's Front-Cover Text is:
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A GNU Manual
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(b) The FSF's Back-Cover Text is:
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You have freedom to copy and modify this GNU Manual, like GNU
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software. Copies published by the Free Software Foundation raise
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funds for GNU development. -->
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<!-- Created by GNU Texinfo 6.4, http://www.gnu.org/software/texinfo/ -->
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<head>
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<title>Variable Attributes (Using the GNU Compiler Collection (GCC))</title>
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<meta name="description" content="Variable Attributes (Using the GNU Compiler Collection (GCC))">
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<meta name="keywords" content="Variable Attributes (Using the GNU Compiler Collection (GCC))">
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<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
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<link href="index.html#Top" rel="start" title="Top">
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<link href="Option-Index.html#Option-Index" rel="index" title="Option Index">
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<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
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<link href="C-Extensions.html#C-Extensions" rel="up" title="C Extensions">
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<link href="Common-Variable-Attributes.html#Common-Variable-Attributes" rel="next" title="Common Variable Attributes">
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<link href="Xstormy16-Function-Attributes.html#Xstormy16-Function-Attributes" rel="prev" title="Xstormy16 Function Attributes">
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</style>
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</head>
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<body lang="en">
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<a name="Variable-Attributes"></a>
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<div class="header">
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<p>
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Next: <a href="Type-Attributes.html#Type-Attributes" accesskey="n" rel="next">Type Attributes</a>, Previous: <a href="Function-Attributes.html#Function-Attributes" accesskey="p" rel="prev">Function Attributes</a>, Up: <a href="C-Extensions.html#C-Extensions" accesskey="u" rel="up">C Extensions</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>
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</div>
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<hr>
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<a name="Specifying-Attributes-of-Variables"></a>
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<h3 class="section">6.32 Specifying Attributes of Variables</h3>
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<a name="index-attribute-of-variables"></a>
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<a name="index-variable-attributes"></a>
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<p>The keyword <code>__attribute__</code> allows you to specify special
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attributes of variables or structure fields. This keyword is followed
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by an attribute specification inside double parentheses. Some
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attributes are currently defined generically for variables.
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Other attributes are defined for variables on particular target
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systems. Other attributes are available for functions
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(see <a href="Function-Attributes.html#Function-Attributes">Function Attributes</a>), labels (see <a href="Label-Attributes.html#Label-Attributes">Label Attributes</a>),
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enumerators (see <a href="Enumerator-Attributes.html#Enumerator-Attributes">Enumerator Attributes</a>), statements
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(see <a href="Statement-Attributes.html#Statement-Attributes">Statement Attributes</a>), and for types (see <a href="Type-Attributes.html#Type-Attributes">Type Attributes</a>).
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Other front ends might define more attributes
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(see <a href="C_002b_002b-Extensions.html#C_002b_002b-Extensions">Extensions to the C++ Language</a>).
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</p>
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<p>See <a href="Attribute-Syntax.html#Attribute-Syntax">Attribute Syntax</a>, for details of the exact syntax for using
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attributes.
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</p>
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<table class="menu" border="0" cellspacing="0">
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<tr><td align="left" valign="top">• <a href="Common-Variable-Attributes.html#Common-Variable-Attributes" accesskey="1">Common Variable Attributes</a>:</td><td> </td><td align="left" valign="top">
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</td></tr>
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<tr><td align="left" valign="top">• <a href="ARC-Variable-Attributes.html#ARC-Variable-Attributes" accesskey="2">ARC Variable Attributes</a>:</td><td> </td><td align="left" valign="top">
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</td></tr>
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<tr><td align="left" valign="top">• <a href="AVR-Variable-Attributes.html#AVR-Variable-Attributes" accesskey="3">AVR Variable Attributes</a>:</td><td> </td><td align="left" valign="top">
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</td></tr>
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<tr><td align="left" valign="top">• <a href="Blackfin-Variable-Attributes.html#Blackfin-Variable-Attributes" accesskey="4">Blackfin Variable Attributes</a>:</td><td> </td><td align="left" valign="top">
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</td></tr>
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<tr><td align="left" valign="top">• <a href="H8_002f300-Variable-Attributes.html#H8_002f300-Variable-Attributes" accesskey="5">H8/300 Variable Attributes</a>:</td><td> </td><td align="left" valign="top">
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</td></tr>
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<tr><td align="left" valign="top">• <a href="IA_002d64-Variable-Attributes.html#IA_002d64-Variable-Attributes" accesskey="6">IA-64 Variable Attributes</a>:</td><td> </td><td align="left" valign="top">
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</td></tr>
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<tr><td align="left" valign="top">• <a href="M32R_002fD-Variable-Attributes.html#M32R_002fD-Variable-Attributes" accesskey="7">M32R/D Variable Attributes</a>:</td><td> </td><td align="left" valign="top">
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</td></tr>
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<tr><td align="left" valign="top">• <a href="MeP-Variable-Attributes.html#MeP-Variable-Attributes" accesskey="8">MeP Variable Attributes</a>:</td><td> </td><td align="left" valign="top">
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</td></tr>
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<tr><td align="left" valign="top">• <a href="Microsoft-Windows-Variable-Attributes.html#Microsoft-Windows-Variable-Attributes" accesskey="9">Microsoft Windows Variable Attributes</a>:</td><td> </td><td align="left" valign="top">
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</td></tr>
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<tr><td align="left" valign="top">• <a href="MSP430-Variable-Attributes.html#MSP430-Variable-Attributes">MSP430 Variable Attributes</a>:</td><td> </td><td align="left" valign="top">
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</td></tr>
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<tr><td align="left" valign="top">• <a href="Nvidia-PTX-Variable-Attributes.html#Nvidia-PTX-Variable-Attributes">Nvidia PTX Variable Attributes</a>:</td><td> </td><td align="left" valign="top">
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</td></tr>
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<tr><td align="left" valign="top">• <a href="PowerPC-Variable-Attributes.html#PowerPC-Variable-Attributes">PowerPC Variable Attributes</a>:</td><td> </td><td align="left" valign="top">
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</td></tr>
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<tr><td align="left" valign="top">• <a href="RL78-Variable-Attributes.html#RL78-Variable-Attributes">RL78 Variable Attributes</a>:</td><td> </td><td align="left" valign="top">
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</td></tr>
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<tr><td align="left" valign="top">• <a href="SPU-Variable-Attributes.html#SPU-Variable-Attributes">SPU Variable Attributes</a>:</td><td> </td><td align="left" valign="top">
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</td></tr>
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<tr><td align="left" valign="top">• <a href="V850-Variable-Attributes.html#V850-Variable-Attributes">V850 Variable Attributes</a>:</td><td> </td><td align="left" valign="top">
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</td></tr>
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<tr><td align="left" valign="top">• <a href="x86-Variable-Attributes.html#x86-Variable-Attributes">x86 Variable Attributes</a>:</td><td> </td><td align="left" valign="top">
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</td></tr>
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<tr><td align="left" valign="top">• <a href="Xstormy16-Variable-Attributes.html#Xstormy16-Variable-Attributes">Xstormy16 Variable Attributes</a>:</td><td> </td><td align="left" valign="top">
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</td></tr>
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</table>
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<hr>
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<div class="header">
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<p>
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Next: <a href="Type-Attributes.html#Type-Attributes" accesskey="n" rel="next">Type Attributes</a>, Previous: <a href="Function-Attributes.html#Function-Attributes" accesskey="p" rel="prev">Function Attributes</a>, Up: <a href="C-Extensions.html#C-Extensions" accesskey="u" rel="up">C Extensions</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>
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</div>
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</body>
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</html>
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