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diff --git a/share/doc/gdb/Breakpoint_002drelated-Warnings.html b/share/doc/gdb/Breakpoint_002drelated-Warnings.html new file mode 100644 index 0000000..84a7a24 --- /dev/null +++ b/share/doc/gdb/Breakpoint_002drelated-Warnings.html @@ -0,0 +1,132 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> +<html> +<!-- Copyright (C) 1988-2023 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 "Free Software" and "Free Software Needs +Free Documentation", with the Front-Cover Texts being "A GNU Manual," +and with the Back-Cover Texts as in (a) below. + +(a) The FSF's Back-Cover Text is: "You are free to copy and modify +this GNU Manual. Buying copies from GNU Press supports the FSF in +developing GNU and promoting software freedom." --> +<!-- Created by GNU Texinfo 5.1, http://www.gnu.org/software/texinfo/ --> +<head> +<title>Debugging with GDB: Breakpoint-related Warnings</title> + +<meta name="description" content="Debugging with GDB: Breakpoint-related Warnings"> +<meta name="keywords" content="Debugging with GDB: Breakpoint-related Warnings"> +<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="Concept-Index.html#Concept-Index" rel="index" title="Concept Index"> +<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents"> +<link href="Breakpoints.html#Breakpoints" rel="up" title="Breakpoints"> +<link href="Continuing-and-Stepping.html#Continuing-and-Stepping" rel="next" title="Continuing and Stepping"> +<link href="Error-in-Breakpoints.html#Error-in-Breakpoints" rel="previous" title="Error in Breakpoints"> +<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="Breakpoint_002drelated-Warnings"></a> +<div class="header"> +<p> +Previous: <a href="Error-in-Breakpoints.html#Error-in-Breakpoints" accesskey="p" rel="previous">Error in Breakpoints</a>, Up: <a href="Breakpoints.html#Breakpoints" accesskey="u" rel="up">Breakpoints</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p> +</div> +<hr> +<a name="g_t_0060_0060Breakpoint-address-adjusted_002e_002e_002e_0027_0027"></a> +<h4 class="subsection">5.1.12 “Breakpoint address adjusted...”</h4> +<a name="index-breakpoint-address-adjusted"></a> + +<p>Some processor architectures place constraints on the addresses at +which breakpoints may be placed. For architectures thus constrained, +<small>GDB</small> will attempt to adjust the breakpoint’s address to comply +with the constraints dictated by the architecture. +</p> +<p>One example of such an architecture is the Fujitsu FR-V. The FR-V is +a VLIW architecture in which a number of RISC-like instructions may be +bundled together for parallel execution. The FR-V architecture +constrains the location of a breakpoint instruction within such a +bundle to the instruction with the lowest address. <small>GDB</small> +honors this constraint by adjusting a breakpoint’s address to the +first in the bundle. +</p> +<p>It is not uncommon for optimized code to have bundles which contain +instructions from different source statements, thus it may happen that +a breakpoint’s address will be adjusted from one source statement to +another. Since this adjustment may significantly alter <small>GDB</small>’s +breakpoint related behavior from what the user expects, a warning is +printed when the breakpoint is first set and also when the breakpoint +is hit. +</p> +<p>A warning like the one below is printed when setting a breakpoint +that’s been subject to address adjustment: +</p> +<div class="smallexample"> +<pre class="smallexample">warning: Breakpoint address adjusted from 0x00010414 to 0x00010410. +</pre></div> + +<p>Such warnings are printed both for user settable and <small>GDB</small>’s +internal breakpoints. If you see one of these warnings, you should +verify that a breakpoint set at the adjusted address will have the +desired affect. If not, the breakpoint in question may be removed and +other breakpoints may be set which will have the desired behavior. +E.g., it may be sufficient to place the breakpoint at a later +instruction. A conditional breakpoint may also be useful in some +cases to prevent the breakpoint from triggering too often. +</p> +<p><small>GDB</small> will also issue a warning when stopping at one of these +adjusted breakpoints: +</p> +<div class="smallexample"> +<pre class="smallexample">warning: Breakpoint 1 address previously adjusted from 0x00010414 +to 0x00010410. +</pre></div> + +<p>When this warning is encountered, it may be too late to take remedial +action except in cases where the breakpoint is hit earlier or more +frequently than expected. +</p> +<hr> +<div class="header"> +<p> +Previous: <a href="Error-in-Breakpoints.html#Error-in-Breakpoints" accesskey="p" rel="previous">Error in Breakpoints</a>, Up: <a href="Breakpoints.html#Breakpoints" accesskey="u" rel="up">Breakpoints</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p> +</div> + + + +</body> +</html> |