'\" t
.\"     Title: __attribute__
.\"    Author: The Khronos Group
.\" Generator: DocBook XSL Stylesheets vsnapshot <http://docbook.sf.net/>
.\"      Date: 01/14/2021
.\"    Manual: OpenCL Manual
.\"    Source: The Khronos Group
.\"  Language: English
.\"
.TH "__ATTRIBUTE__" "3clc" "01/14/2021" "The Khronos Group" "OpenCL Manual"
.\" -----------------------------------------------------------------
.\" * Define some portability stuff
.\" -----------------------------------------------------------------
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.\" http://bugs.debian.org/507673
.\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.ie \n(.g .ds Aq \(aq
.el       .ds Aq '
.\" -----------------------------------------------------------------
.\" * set default formatting
.\" -----------------------------------------------------------------
.\" disable hyphenation
.nh
.\" disable justification (adjust text to left margin only)
.ad l
.\" -----------------------------------------------------------------
.\" * MAIN CONTENT STARTS HERE *
.\" -----------------------------------------------------------------
.SH "NAME"
__attribute__
.SS ""
.TS
tab(:);
l.
T{
__attribute__ ((\fIattribute\-list\fR))

attribute\-list:
attribute<sub>opt</sub>
attribute\-list, attribute<sub>opt</sub>

attribute:
attribute\-token attribute\-argument\-clause<sub>opt</sub>

attribute\-token:
identifier

attribute\-argument\-clause:
( attribute\-argument\-list )

attribute\-argument\-list:
attribute\-argument
attribute\-argument\-list, attribute\-argument

attribute\-argument:
assignment\-expression
T}
.TE
.sp 1
.SH "DESCRIPTION"
.PP
This section describes the syntax with which
__attribute__
may be used, and the constructs to which attribute specifiers bind\&.
.PP
An attribute specifier is of the form
\fB__attribute__ ((\fR\fB\fIattribute\-list\fR\fR\fB))\fR\&.
.PP
This syntax is taken directly from GCC but unlike GCC, which allows attributes to be applied only to functions, types, and variables, OpenCL attributes can be associated with:
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
\fBattributes-types\fR(3clc)
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
\fBfunctionQualifiers\fR(3clc)
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
\fBattributes-variables\fR(3clc)
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
\fBattributes-blocksAndControlFlow\fR(3clc)
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
\fBattributes-blocksAndControlFlow\fR(3clc)
.RE
.PP
In general, the rules for how an attribute binds for a given context are non\-trivial and the reader is pointed to GCC\*(Aqs documentation and Maurer and Wong\*(Aqs paper (See the "References" section in the
\m[blue]\fBOpenCL specification\fR\m[]\&\s-2\u[1]\d\s+2
for details\&.)
.SH "SPECIFICATION"
.PP
\m[blue]\fBOpenCL Specification\fR\m[]\&\s-2\u[2]\d\s+2
.SH "SEE ALSO"
.PP
\fBattributes-types\fR(3clc),
\fBattributes-variables\fR(3clc),
\fBattributes-blocksAndControlFlow\fR(3clc),
\fBfunctionQualifiers\fR(3clc)
.SH "AUTHORS"
.PP
\fBThe Khronos Group\fR
.SH "COPYRIGHT"
.br
Copyright \(co 2007-2011 The Khronos Group Inc.
.br
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and/or associated documentation files (the "Materials"), to deal in the Materials without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Materials, and to permit persons to whom the Materials are furnished to do so, subject to the condition that this copyright notice and permission notice shall be included in all copies or substantial portions of the Materials.
.sp
.SH "NOTES"
.IP " 1." 4
OpenCL specification
.RS 4
\%page 355, section 11 - References (to Wong paper)  
.RE
.IP " 2." 4
OpenCL Specification
.RS 4
\%page 236, section 6.11. - Attribute Qualifiers
.RE