You cannot select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

118 lines
5.8 KiB
HTML

<html lang="en">
<head>
<title>All Debuggers - GNU Compiler Collection (GCC) Internals</title>
<meta http-equiv="Content-Type" content="text/html">
<meta name="description" content="GNU Compiler Collection (GCC) Internals">
<meta name="generator" content="makeinfo 4.13">
<link title="Top" rel="start" href="index.html#Top">
<link rel="up" href="Debugging-Info.html#Debugging-Info" title="Debugging Info">
<link rel="next" href="DBX-Options.html#DBX-Options" title="DBX Options">
<link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage">
<!--
Copyright (C) 1988-2015 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.-->
<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>
</head>
<body>
<div class="node">
<a name="All-Debuggers"></a>
<p>
Next:&nbsp;<a rel="next" accesskey="n" href="DBX-Options.html#DBX-Options">DBX Options</a>,
Up:&nbsp;<a rel="up" accesskey="u" href="Debugging-Info.html#Debugging-Info">Debugging Info</a>
<hr>
</div>
<h4 class="subsection">17.21.1 Macros Affecting All Debugging Formats</h4>
<!-- prevent bad page break with this line -->
<p>These macros affect all debugging formats.
<div class="defun">
&mdash; Macro: <b>DBX_REGISTER_NUMBER</b> (<var>regno</var>)<var><a name="index-DBX_005fREGISTER_005fNUMBER-4750"></a></var><br>
<blockquote><p>A C expression that returns the DBX register number for the compiler
register number <var>regno</var>. In the default macro provided, the value
of this expression will be <var>regno</var> itself. But sometimes there are
some registers that the compiler knows about and DBX does not, or vice
versa. In such cases, some register may need to have one number in the
compiler and another for DBX.
<p>If two registers have consecutive numbers inside GCC, and they can be
used as a pair to hold a multiword value, then they <em>must</em> have
consecutive numbers after renumbering with <code>DBX_REGISTER_NUMBER</code>.
Otherwise, debuggers will be unable to access such a pair, because they
expect register pairs to be consecutive in their own numbering scheme.
<p>If you find yourself defining <code>DBX_REGISTER_NUMBER</code> in way that
does not preserve register pairs, then what you must do instead is
redefine the actual register numbering scheme.
</p></blockquote></div>
<div class="defun">
&mdash; Macro: <b>DEBUGGER_AUTO_OFFSET</b> (<var>x</var>)<var><a name="index-DEBUGGER_005fAUTO_005fOFFSET-4751"></a></var><br>
<blockquote><p>A C expression that returns the integer offset value for an automatic
variable having address <var>x</var> (an RTL expression). The default
computation assumes that <var>x</var> is based on the frame-pointer and
gives the offset from the frame-pointer. This is required for targets
that produce debugging output for DBX or COFF-style debugging output
for SDB and allow the frame-pointer to be eliminated when the
<samp><span class="option">-g</span></samp> options is used.
</p></blockquote></div>
<div class="defun">
&mdash; Macro: <b>DEBUGGER_ARG_OFFSET</b> (<var>offset, x</var>)<var><a name="index-DEBUGGER_005fARG_005fOFFSET-4752"></a></var><br>
<blockquote><p>A C expression that returns the integer offset value for an argument
having address <var>x</var> (an RTL expression). The nominal offset is
<var>offset</var>.
</p></blockquote></div>
<div class="defun">
&mdash; Macro: <b>PREFERRED_DEBUGGING_TYPE</b><var><a name="index-PREFERRED_005fDEBUGGING_005fTYPE-4753"></a></var><br>
<blockquote><p>A C expression that returns the type of debugging output GCC should
produce when the user specifies just <samp><span class="option">-g</span></samp>. Define
this if you have arranged for GCC to support more than one format of
debugging output. Currently, the allowable values are <code>DBX_DEBUG</code>,
<code>SDB_DEBUG</code>, <code>DWARF_DEBUG</code>, <code>DWARF2_DEBUG</code>,
<code>XCOFF_DEBUG</code>, <code>VMS_DEBUG</code>, and <code>VMS_AND_DWARF2_DEBUG</code>.
<p>When the user specifies <samp><span class="option">-ggdb</span></samp>, GCC normally also uses the
value of this macro to select the debugging output format, but with two
exceptions. If <code>DWARF2_DEBUGGING_INFO</code> is defined, GCC uses the
value <code>DWARF2_DEBUG</code>. Otherwise, if <code>DBX_DEBUGGING_INFO</code> is
defined, GCC uses <code>DBX_DEBUG</code>.
<p>The value of this macro only affects the default debugging output; the
user can always get a specific type of output by using <samp><span class="option">-gstabs</span></samp>,
<samp><span class="option">-gcoff</span></samp>, <samp><span class="option">-gdwarf-2</span></samp>, <samp><span class="option">-gxcoff</span></samp>, or <samp><span class="option">-gvms</span></samp>.
</p></blockquote></div>
</body></html>