246 lines
12 KiB
HTML
246 lines
12 KiB
HTML
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
|
|
<html>
|
|
<!-- Copyright (C) 1988-2016 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>Using the GNU Compiler Collection (GCC): Directory Options</title>
|
|
|
|
<meta name="description" content="Using the GNU Compiler Collection (GCC): Directory Options">
|
|
<meta name="keywords" content="Using the GNU Compiler Collection (GCC): Directory Options">
|
|
<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="Invoking-GCC.html#Invoking-GCC" rel="up" title="Invoking GCC">
|
|
<link href="Code-Gen-Options.html#Code-Gen-Options" rel="next" title="Code Gen Options">
|
|
<link href="Link-Options.html#Link-Options" rel="prev" title="Link Options">
|
|
<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="Directory-Options"></a>
|
|
<div class="header">
|
|
<p>
|
|
Next: <a href="Code-Gen-Options.html#Code-Gen-Options" accesskey="n" rel="next">Code Gen Options</a>, Previous: <a href="Link-Options.html#Link-Options" accesskey="p" rel="prev">Link Options</a>, Up: <a href="Invoking-GCC.html#Invoking-GCC" accesskey="u" rel="up">Invoking GCC</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="Options-for-Directory-Search"></a>
|
|
<h3 class="section">3.15 Options for Directory Search</h3>
|
|
<a name="index-directory-options"></a>
|
|
<a name="index-options_002c-directory-search"></a>
|
|
<a name="index-search-path"></a>
|
|
|
|
<p>These options specify directories to search for header files, for
|
|
libraries and for parts of the compiler:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt><code>-I<var>dir</var></code></dt>
|
|
<dd><a name="index-I-1"></a>
|
|
<p>Add the directory <var>dir</var> to the head of the list of directories to be
|
|
searched for header files. This can be used to override a system header
|
|
file, substituting your own version, since these directories are
|
|
searched before the system header file directories. However, you should
|
|
not use this option to add directories that contain vendor-supplied
|
|
system header files (use <samp>-isystem</samp> for that). If you use more than
|
|
one <samp>-I</samp> option, the directories are scanned in left-to-right
|
|
order; the standard system directories come after.
|
|
</p>
|
|
<p>If a standard system include directory, or a directory specified with
|
|
<samp>-isystem</samp>, is also specified with <samp>-I</samp>, the <samp>-I</samp>
|
|
option is ignored. The directory is still searched but as a
|
|
system directory at its normal position in the system include chain.
|
|
This is to ensure that GCC’s procedure to fix buggy system headers and
|
|
the ordering for the <code>include_next</code> directive are not inadvertently changed.
|
|
If you really need to change the search order for system directories,
|
|
use the <samp>-nostdinc</samp> and/or <samp>-isystem</samp> options.
|
|
</p>
|
|
</dd>
|
|
<dt><code>-iplugindir=<var>dir</var></code></dt>
|
|
<dd><a name="index-iplugindir_003d"></a>
|
|
<p>Set the directory to search for plugins that are passed
|
|
by <samp>-fplugin=<var>name</var></samp> instead of
|
|
<samp>-fplugin=<var>path</var>/<var>name</var>.so</samp>. This option is not meant
|
|
to be used by the user, but only passed by the driver.
|
|
</p>
|
|
</dd>
|
|
<dt><code>-iquote<var>dir</var></code></dt>
|
|
<dd><a name="index-iquote-1"></a>
|
|
<p>Add the directory <var>dir</var> to the head of the list of directories to
|
|
be searched for header files only for the case of <code>#include
|
|
"<var>file</var>"</code>; they are not searched for <code>#include <<var>file</var>></code>,
|
|
otherwise just like <samp>-I</samp>.
|
|
</p>
|
|
</dd>
|
|
<dt><code>-L<var>dir</var></code></dt>
|
|
<dd><a name="index-L"></a>
|
|
<p>Add directory <var>dir</var> to the list of directories to be searched
|
|
for <samp>-l</samp>.
|
|
</p>
|
|
</dd>
|
|
<dt><code>-B<var>prefix</var></code></dt>
|
|
<dd><a name="index-B"></a>
|
|
<p>This option specifies where to find the executables, libraries,
|
|
include files, and data files of the compiler itself.
|
|
</p>
|
|
<p>The compiler driver program runs one or more of the subprograms
|
|
<code>cpp</code>, <code>cc1</code>, <code>as</code> and <code>ld</code>. It tries
|
|
<var>prefix</var> as a prefix for each program it tries to run, both with and
|
|
without ‘<samp><var>machine</var>/<var>version</var>/</samp>’ for the corresponding target
|
|
machine and compiler version.
|
|
</p>
|
|
<p>For each subprogram to be run, the compiler driver first tries the
|
|
<samp>-B</samp> prefix, if any. If that name is not found, or if <samp>-B</samp>
|
|
is not specified, the driver tries two standard prefixes,
|
|
<samp>/usr/lib/gcc/</samp> and <samp>/usr/local/lib/gcc/</samp>. If neither of
|
|
those results in a file name that is found, the unmodified program
|
|
name is searched for using the directories specified in your
|
|
<code>PATH</code> environment variable.
|
|
</p>
|
|
<p>The compiler checks to see if the path provided by <samp>-B</samp>
|
|
refers to a directory, and if necessary it adds a directory
|
|
separator character at the end of the path.
|
|
</p>
|
|
<p><samp>-B</samp> prefixes that effectively specify directory names also apply
|
|
to libraries in the linker, because the compiler translates these
|
|
options into <samp>-L</samp> options for the linker. They also apply to
|
|
include files in the preprocessor, because the compiler translates these
|
|
options into <samp>-isystem</samp> options for the preprocessor. In this case,
|
|
the compiler appends ‘<samp>include</samp>’ to the prefix.
|
|
</p>
|
|
<p>The runtime support file <samp>libgcc.a</samp> can also be searched for using
|
|
the <samp>-B</samp> prefix, if needed. If it is not found there, the two
|
|
standard prefixes above are tried, and that is all. The file is left
|
|
out of the link if it is not found by those means.
|
|
</p>
|
|
<p>Another way to specify a prefix much like the <samp>-B</samp> prefix is to use
|
|
the environment variable <code>GCC_EXEC_PREFIX</code>. See <a href="Environment-Variables.html#Environment-Variables">Environment Variables</a>.
|
|
</p>
|
|
<p>As a special kludge, if the path provided by <samp>-B</samp> is
|
|
<samp>[dir/]stage<var>N</var>/</samp>, where <var>N</var> is a number in the range 0 to
|
|
9, then it is replaced by <samp>[dir/]include</samp>. This is to help
|
|
with boot-strapping the compiler.
|
|
</p>
|
|
</dd>
|
|
<dt><code>-no-canonical-prefixes</code></dt>
|
|
<dd><a name="index-no_002dcanonical_002dprefixes"></a>
|
|
<p>Do not expand any symbolic links, resolve references to ‘<samp>/../</samp>’
|
|
or ‘<samp>/./</samp>’, or make the path absolute when generating a relative
|
|
prefix.
|
|
</p>
|
|
</dd>
|
|
<dt><code>--sysroot=<var>dir</var></code></dt>
|
|
<dd><a name="index-sysroot"></a>
|
|
<p>Use <var>dir</var> as the logical root directory for headers and libraries.
|
|
For example, if the compiler normally searches for headers in
|
|
<samp>/usr/include</samp> and libraries in <samp>/usr/lib</samp>, it instead
|
|
searches <samp><var>dir</var>/usr/include</samp> and <samp><var>dir</var>/usr/lib</samp>.
|
|
</p>
|
|
<p>If you use both this option and the <samp>-isysroot</samp> option, then
|
|
the <samp>--sysroot</samp> option applies to libraries, but the
|
|
<samp>-isysroot</samp> option applies to header files.
|
|
</p>
|
|
<p>The GNU linker (beginning with version 2.16) has the necessary support
|
|
for this option. If your linker does not support this option, the
|
|
header file aspect of <samp>--sysroot</samp> still works, but the
|
|
library aspect does not.
|
|
</p>
|
|
</dd>
|
|
<dt><code>--no-sysroot-suffix</code></dt>
|
|
<dd><a name="index-no_002dsysroot_002dsuffix"></a>
|
|
<p>For some targets, a suffix is added to the root directory specified
|
|
with <samp>--sysroot</samp>, depending on the other options used, so that
|
|
headers may for example be found in
|
|
<samp><var>dir</var>/<var>suffix</var>/usr/include</samp> instead of
|
|
<samp><var>dir</var>/usr/include</samp>. This option disables the addition of
|
|
such a suffix.
|
|
</p>
|
|
</dd>
|
|
<dt><code>-I-</code></dt>
|
|
<dd><a name="index-I_002d-1"></a>
|
|
<p>This option has been deprecated. Please use <samp>-iquote</samp> instead for
|
|
<samp>-I</samp> directories before the <samp>-I-</samp> and remove the <samp>-I-</samp>
|
|
option.
|
|
Any directories you specify with <samp>-I</samp> options before the <samp>-I-</samp>
|
|
option are searched only for the case of <code>#include "<var>file</var>"</code>;
|
|
they are not searched for <code>#include <<var>file</var>></code>.
|
|
</p>
|
|
<p>If additional directories are specified with <samp>-I</samp> options after
|
|
the <samp>-I-</samp> option, these directories are searched for all <code>#include</code>
|
|
directives. (Ordinarily <em>all</em> <samp>-I</samp> directories are used
|
|
this way.)
|
|
</p>
|
|
<p>In addition, the <samp>-I-</samp> option inhibits the use of the current
|
|
directory (where the current input file came from) as the first search
|
|
directory for <code>#include "<var>file</var>"</code>. There is no way to
|
|
override this effect of <samp>-I-</samp>. With <samp>-I.</samp> you can specify
|
|
searching the directory that is current when the compiler is
|
|
invoked. That is not exactly the same as what the preprocessor does
|
|
by default, but it is often satisfactory.
|
|
</p>
|
|
<p><samp>-I-</samp> does not inhibit the use of the standard system directories
|
|
for header files. Thus, <samp>-I-</samp> and <samp>-nostdinc</samp> are
|
|
independent.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<hr>
|
|
<div class="header">
|
|
<p>
|
|
Next: <a href="Code-Gen-Options.html#Code-Gen-Options" accesskey="n" rel="next">Code Gen Options</a>, Previous: <a href="Link-Options.html#Link-Options" accesskey="p" rel="prev">Link Options</a>, Up: <a href="Invoking-GCC.html#Invoking-GCC" accesskey="u" rel="up">Invoking GCC</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>
|