| <html lang="en"> |
| <head> |
| <title>Environment - Untitled</title> |
| <meta http-equiv="Content-Type" content="text/html"> |
| <meta name="description" content="Untitled"> |
| <meta name="generator" content="makeinfo 4.13"> |
| <link title="Top" rel="start" href="index.html#Top"> |
| <link rel="up" href="Invocation.html#Invocation" title="Invocation"> |
| <link rel="prev" href="Options.html#Options" title="Options"> |
| <link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage"> |
| <!-- |
| This file documents the GNU linker LD |
| (Sourcery G++ Lite 2011.03-41) |
| version 2.20.51. |
| |
| Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, |
| 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 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 no Invariant Sections, with no Front-Cover Texts, and with no |
| Back-Cover Texts. A copy of the license is included in the |
| section entitled ``GNU Free Documentation License''.--> |
| <meta http-equiv="Content-Style-Type" content="text/css"> |
| <style type="text/css"><!-- |
| pre.display { font-family:inherit } |
| pre.format { font-family:inherit } |
| pre.smalldisplay { font-family:inherit; font-size:smaller } |
| pre.smallformat { font-family:inherit; font-size:smaller } |
| pre.smallexample { font-size:smaller } |
| pre.smalllisp { font-size:smaller } |
| span.sc { font-variant:small-caps } |
| span.roman { font-family:serif; font-weight:normal; } |
| span.sansserif { font-family:sans-serif; font-weight:normal; } |
| --></style> |
| <link rel="stylesheet" type="text/css" href="../cs.css"> |
| </head> |
| <body> |
| <div class="node"> |
| <a name="Environment"></a> |
| <p> |
| Previous: <a rel="previous" accesskey="p" href="Options.html#Options">Options</a>, |
| Up: <a rel="up" accesskey="u" href="Invocation.html#Invocation">Invocation</a> |
| <hr> |
| </div> |
| |
| <h3 class="section">2.2 Environment Variables</h3> |
| |
| <!-- man begin ENVIRONMENT --> |
| <p>You can change the behaviour of <samp><span class="command">ld</span></samp> with the environment variables |
| <code>GNUTARGET</code>, |
| <code>LDEMULATION</code> and <code>COLLECT_NO_DEMANGLE</code>. |
| |
| <p><a name="index-GNUTARGET-327"></a><a name="index-default-input-format-328"></a><code>GNUTARGET</code> determines the input-file object format if you don't |
| use ‘<samp><span class="samp">-b</span></samp>’ (or its synonym ‘<samp><span class="samp">--format</span></samp>’). Its value should be one |
| of the BFD names for an input format (see <a href="BFD.html#BFD">BFD</a>). If there is no |
| <code>GNUTARGET</code> in the environment, <samp><span class="command">ld</span></samp> uses the natural format |
| of the target. If <code>GNUTARGET</code> is set to <code>default</code> then BFD |
| attempts to discover the input format by examining binary input files; |
| this method often succeeds, but there are potential ambiguities, since |
| there is no method of ensuring that the magic number used to specify |
| object-file formats is unique. However, the configuration procedure for |
| BFD on each system places the conventional format for that system first |
| in the search-list, so ambiguities are resolved in favor of convention. |
| |
| <p><a name="index-LDEMULATION-329"></a><a name="index-default-emulation-330"></a><a name="index-emulation_002c-default-331"></a><code>LDEMULATION</code> determines the default emulation if you don't use the |
| ‘<samp><span class="samp">-m</span></samp>’ option. The emulation can affect various aspects of linker |
| behaviour, particularly the default linker script. You can list the |
| available emulations with the ‘<samp><span class="samp">--verbose</span></samp>’ or ‘<samp><span class="samp">-V</span></samp>’ options. If |
| the ‘<samp><span class="samp">-m</span></samp>’ option is not used, and the <code>LDEMULATION</code> environment |
| variable is not defined, the default emulation depends upon how the |
| linker was configured. |
| |
| <p><a name="index-COLLECT_005fNO_005fDEMANGLE-332"></a><a name="index-demangling_002c-default-333"></a>Normally, the linker will default to demangling symbols. However, if |
| <code>COLLECT_NO_DEMANGLE</code> is set in the environment, then it will |
| default to not demangling symbols. This environment variable is used in |
| a similar fashion by the <code>gcc</code> linker wrapper program. The default |
| may be overridden by the ‘<samp><span class="samp">--demangle</span></samp>’ and ‘<samp><span class="samp">--no-demangle</span></samp>’ |
| options. |
| |
| <!-- man end --> |
| </body></html> |
| |