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diff --git a/share/doc/gdb/Writing-JIT-Debug-Info-Readers.html b/share/doc/gdb/Writing-JIT-Debug-Info-Readers.html new file mode 100644 index 0000000..96bc9c7 --- /dev/null +++ b/share/doc/gdb/Writing-JIT-Debug-Info-Readers.html @@ -0,0 +1,142 @@ +<!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: Writing JIT Debug Info Readers</title> + +<meta name="description" content="Debugging with GDB: Writing JIT Debug Info Readers"> +<meta name="keywords" content="Debugging with GDB: Writing JIT Debug Info Readers"> +<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="Custom-Debug-Info.html#Custom-Debug-Info" rel="up" title="Custom Debug Info"> +<link href="In_002dProcess-Agent.html#In_002dProcess-Agent" rel="next" title="In-Process Agent"> +<link href="Using-JIT-Debug-Info-Readers.html#Using-JIT-Debug-Info-Readers" rel="previous" title="Using JIT Debug Info Readers"> +<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="Writing-JIT-Debug-Info-Readers"></a> +<div class="header"> +<p> +Previous: <a href="Using-JIT-Debug-Info-Readers.html#Using-JIT-Debug-Info-Readers" accesskey="p" rel="previous">Using JIT Debug Info Readers</a>, Up: <a href="Custom-Debug-Info.html#Custom-Debug-Info" accesskey="u" rel="up">Custom Debug Info</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="Writing-JIT-Debug-Info-Readers-1"></a> +<h4 class="subsection">29.4.2 Writing JIT Debug Info Readers</h4> +<a name="index-writing-JIT-debug-info-readers"></a> + +<p>As mentioned, a reader is essentially a shared object conforming to a +certain ABI. This ABI is described in <samp>jit-reader.h</samp>. +</p> +<p><samp>jit-reader.h</samp> defines the structures, macros and functions +required to write a reader. It is installed (along with +<small>GDB</small>), in <samp><var>includedir</var>/gdb</samp> where <var>includedir</var> is +the system include directory. +</p> +<p>Readers need to be released under a GPL compatible license. A reader +can be declared as released under such a license by placing the macro +<code>GDB_DECLARE_GPL_COMPATIBLE_READER</code> in a source file. +</p> +<p>The entry point for readers is the symbol <code>gdb_init_reader</code>, +which is expected to be a function with the prototype +</p> +<a name="index-gdb_005finit_005freader"></a> +<div class="smallexample"> +<pre class="smallexample">extern struct gdb_reader_funcs *gdb_init_reader (void); +</pre></div> + +<a name="index-struct-gdb_005freader_005ffuncs"></a> + +<p><code>struct gdb_reader_funcs</code> contains a set of pointers to callback +functions. These functions are executed to read the debug info +generated by the JIT compiler (<code>read</code>), to unwind stack frames +(<code>unwind</code>) and to create canonical frame IDs +(<code>get_frame_id</code>). It also has a callback that is called when the +reader is being unloaded (<code>destroy</code>). The struct looks like this +</p> +<div class="smallexample"> +<pre class="smallexample">struct gdb_reader_funcs +{ + /* Must be set to GDB_READER_INTERFACE_VERSION. */ + int reader_version; + + /* For use by the reader. */ + void *priv_data; + + gdb_read_debug_info *read; + gdb_unwind_frame *unwind; + gdb_get_frame_id *get_frame_id; + gdb_destroy_reader *destroy; +}; +</pre></div> + +<a name="index-struct-gdb_005fsymbol_005fcallbacks"></a> +<a name="index-struct-gdb_005funwind_005fcallbacks"></a> + +<p>The callbacks are provided with another set of callbacks by +<small>GDB</small> to do their job. For <code>read</code>, these callbacks are +passed in a <code>struct gdb_symbol_callbacks</code> and for <code>unwind</code> +and <code>get_frame_id</code>, in a <code>struct gdb_unwind_callbacks</code>. +<code>struct gdb_symbol_callbacks</code> has callbacks to create new object +files and new symbol tables inside those object files. <code>struct +gdb_unwind_callbacks</code> has callbacks to read registers off the current +frame and to write out the values of the registers in the previous +frame. Both have a callback (<code>target_read</code>) to read bytes off the +target’s address space. +</p> +<hr> +<div class="header"> +<p> +Previous: <a href="Using-JIT-Debug-Info-Readers.html#Using-JIT-Debug-Info-Readers" accesskey="p" rel="previous">Using JIT Debug Info Readers</a>, Up: <a href="Custom-Debug-Info.html#Custom-Debug-Info" accesskey="u" rel="up">Custom Debug Info</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> |