URL
https://opencores.org/ocsvn/openrisc/openrisc/trunk
Subversion Repositories openrisc
[/] [openrisc/] [trunk/] [rtos/] [ecos-2.0/] [doc/] [html/] [cdl-guide/] [ref.no-define.html] - Rev 757
Go to most recent revision | Compare with Previous | Blame | View Log
<!-- Copyright (C) 2003 Red Hat, Inc. -->
<!-- This material may be distributed only subject to the terms -->
<!-- and conditions set forth in the Open Publication License, v1.0 -->
<!-- or later (the latest version is presently available at -->
<!-- http://www.opencontent.org/openpub/). -->
<!-- Distribution of the work or derivative of the work in any -->
<!-- standard (paper) book form is prohibited unless prior -->
<!-- permission is obtained from the copyright holder. -->
<HTML
><HEAD
><TITLE
>no_define</TITLE
><meta name="MSSmartTagsPreventParsing" content="TRUE">
<META
NAME="GENERATOR"
CONTENT="Modular DocBook HTML Stylesheet Version 1.76b+
"><LINK
REL="HOME"
TITLE="The eCos Component Writer's Guide"
HREF="cdl-guide.html"><LINK
REL="UP"
TITLE="CDL Language Specification"
HREF="reference.html"><LINK
REL="PREVIOUS"
TITLE="make_object"
HREF="ref.make-object.html"><LINK
REL="NEXT"
TITLE="parent"
HREF="ref.parent.html"></HEAD
><BODY
CLASS="REFENTRY"
BGCOLOR="#FFFFFF"
TEXT="#000000"
LINK="#0000FF"
VLINK="#840084"
ALINK="#0000FF"
><DIV
CLASS="NAVHEADER"
><TABLE
SUMMARY="Header navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TH
COLSPAN="3"
ALIGN="center"
>The <SPAN
CLASS="APPLICATION"
>eCos</SPAN
> Component Writer's Guide</TH
></TR
><TR
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="bottom"
><A
HREF="ref.make-object.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="80%"
ALIGN="center"
VALIGN="bottom"
></TD
><TD
WIDTH="10%"
ALIGN="right"
VALIGN="bottom"
><A
HREF="ref.parent.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
></TABLE
><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><H1
><A
NAME="REF.NO-DEFINE"><SPAN
CLASS="PROPERTY"
>no_define</SPAN
></H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN4836"
></A
><H2
>Name</H2
>Property <SPAN
CLASS="PROPERTY"
>no_define</SPAN
> -- Suppress the normal generation of a preprocessor
<TT
CLASS="LITERAL"
>#define</TT
> symbol in a configuration header file.</DIV
><DIV
CLASS="REFSYNOPSISDIV"
><A
NAME="AEN4841"><H2
>Synopsis</H2
><TABLE
BORDER="5"
BGCOLOR="#E0E0F0"
WIDTH="70%"
><TR
><TD
><PRE
CLASS="SYNOPSIS"
>cdl_option <name> {
no_define
…
}</PRE
></TD
></TR
></TABLE
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN4843"
></A
><H2
>Description</H2
><P
>By default all active and enabled properties result in either one or
two <TT
CLASS="LITERAL"
>#define'd</TT
> symbols in the package's
configuration header file, and this is one of the main ways in which
options can affect packages at build-time. It is possible to suppress
the default <TT
CLASS="LITERAL"
>#define's</TT
> by specifying a
<SPAN
CLASS="PROPERTY"
>no_define</SPAN
> property in the body of an option or other <SPAN
CLASS="APPLICATION"
>CDL</SPAN
> entity.
This property takes no arguments and should occur only once in a given
body. </P
><P
>The <SPAN
CLASS="PROPERTY"
>no_define</SPAN
> property is frequently used in conjunction with one of
the other header-file related properties such as <SPAN
CLASS="PROPERTY"
>define</SPAN
>. If one of
the other properties is used to export the required information to a
configuration header file then often there is little point in
exporting the default <TT
CLASS="LITERAL"
>#define</TT
> as
well — in fact there could be a name clash. The
<SPAN
CLASS="PROPERTY"
>no_define</SPAN
> property can also be useful if the sole purpose of an
option is to affect which files get built, and the default
<TT
CLASS="LITERAL"
>#define</TT
> would never get tested in any source code.
However in such cases the default <TT
CLASS="LITERAL"
>#define</TT
> is
mostly harmless and there is little to be gained by suppressing it.</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN4857"
></A
><H2
>Example</H2
><TABLE
BORDER="5"
BGCOLOR="#E0E0F0"
WIDTH="70%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>cdl_component CYG_HAL_STARTUP {
display "Startup type"
flavor data
legal_values { "RAM" "ROM" }
default_value {"RAM"}
no_define
define -file system.h CYG_HAL_STARTUP
…
}</PRE
></TD
></TR
></TABLE
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN4860"
></A
><H2
>See Also</H2
><P
>Properties <A
HREF="ref.define.html"
><SPAN
CLASS="PROPERTY"
>define</SPAN
></A
>,
<A
HREF="ref.define-format.html"
><SPAN
CLASS="PROPERTY"
>define_format</SPAN
></A
>,
<A
HREF="ref.define-header.html"
><SPAN
CLASS="PROPERTY"
>define_header</SPAN
></A
>,
<A
HREF="ref.define-proc.html"
><SPAN
CLASS="PROPERTY"
>define_proc</SPAN
></A
> and
<A
HREF="ref.if-define.html"
><SPAN
CLASS="PROPERTY"
>if_define</SPAN
></A
>.</P
></DIV
><DIV
CLASS="NAVFOOTER"
><HR
ALIGN="LEFT"
WIDTH="100%"><TABLE
SUMMARY="Footer navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
><A
HREF="ref.make-object.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="cdl-guide.html"
ACCESSKEY="H"
>Home</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
><A
HREF="ref.parent.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
><SPAN
CLASS="PROPERTY"
>make_object</SPAN
></TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="reference.html"
ACCESSKEY="U"
>Up</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
><SPAN
CLASS="PROPERTY"
>parent</SPAN
></TD
></TR
></TABLE
></DIV
></BODY
></HTML
> Go to most recent revision | Compare with Previous | Blame | View Log