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| author | alk3pInjection <webmaster@raspii.tech> | 2024-02-04 16:16:35 +0800 |
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| committer | alk3pInjection <webmaster@raspii.tech> | 2024-02-04 16:16:35 +0800 |
| commit | abdaadbcae30fe0c9a66c7516798279fdfd97750 (patch) | |
| tree | 00a54a6e25601e43876d03c1a4a12a749d4a914c /share/doc/gdb/Frames-In-Python.html | |
https://developer.arm.com/downloads/-/arm-gnu-toolchain-downloads
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diff --git a/share/doc/gdb/Frames-In-Python.html b/share/doc/gdb/Frames-In-Python.html new file mode 100644 index 0000000..6edf740 --- /dev/null +++ b/share/doc/gdb/Frames-In-Python.html @@ -0,0 +1,341 @@ +<!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: Frames In Python</title> + +<meta name="description" content="Debugging with GDB: Frames In Python"> +<meta name="keywords" content="Debugging with GDB: Frames In Python"> +<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="Python-API.html#Python-API" rel="up" title="Python API"> +<link href="Blocks-In-Python.html#Blocks-In-Python" rel="next" title="Blocks In Python"> +<link href="Objfiles-In-Python.html#Objfiles-In-Python" rel="previous" title="Objfiles In Python"> +<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="Frames-In-Python"></a> +<div class="header"> +<p> +Next: <a href="Blocks-In-Python.html#Blocks-In-Python" accesskey="n" rel="next">Blocks In Python</a>, Previous: <a href="Objfiles-In-Python.html#Objfiles-In-Python" accesskey="p" rel="previous">Objfiles In Python</a>, Up: <a href="Python-API.html#Python-API" accesskey="u" rel="up">Python API</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="Accessing-inferior-stack-frames-from-Python"></a> +<h4 class="subsubsection">23.3.2.26 Accessing inferior stack frames from Python</h4> + +<a name="index-frames-in-python"></a> +<p>When the debugged program stops, <small>GDB</small> is able to analyze its call +stack (see <a href="Frames.html#Frames">Stack frames</a>). The <code>gdb.Frame</code> class +represents a frame in the stack. A <code>gdb.Frame</code> object is only valid +while its corresponding frame exists in the inferior’s stack. If you try +to use an invalid frame object, <small>GDB</small> will throw a <code>gdb.error</code> +exception (see <a href="Exception-Handling.html#Exception-Handling">Exception Handling</a>). +</p> +<p>Two <code>gdb.Frame</code> objects can be compared for equality with the <code>==</code> +operator, like: +</p> +<div class="smallexample"> +<pre class="smallexample">(gdb) python print gdb.newest_frame() == gdb.selected_frame () +True +</pre></div> + +<p>The following frame-related functions are available in the <code>gdb</code> module: +</p> +<a name="index-gdb_002eselected_005fframe"></a> +<dl> +<dt><a name="index-gdb_002eselected_005fframe-1"></a>Function: <strong>gdb.selected_frame</strong> <em>()</em></dt> +<dd><p>Return the selected frame object. (see <a href="Selection.html#Selection">Selecting a Frame</a>). +</p></dd></dl> + +<a name="index-gdb_002enewest_005fframe"></a> +<dl> +<dt><a name="index-gdb_002enewest_005fframe-1"></a>Function: <strong>gdb.newest_frame</strong> <em>()</em></dt> +<dd><p>Return the newest frame object for the selected thread. +</p></dd></dl> + +<dl> +<dt><a name="index-gdb_002eframe_005fstop_005freason_005fstring"></a>Function: <strong>gdb.frame_stop_reason_string</strong> <em>(reason)</em></dt> +<dd><p>Return a string explaining the reason why <small>GDB</small> stopped unwinding +frames, as expressed by the given <var>reason</var> code (an integer, see the +<code>unwind_stop_reason</code> method further down in this section). +</p></dd></dl> + +<a name="index-gdb_002einvalidate_005fcached_005fframes"></a> +<dl> +<dt><a name="index-gdb_002einvalidate_005fcached_005fframes-1"></a>Function: <strong>gdb.invalidate_cached_frames</strong></dt> +<dd><p><small>GDB</small> internally keeps a cache of the frames that have been +unwound. This function invalidates this cache. +</p> +<p>This function should not generally be called by ordinary Python code. +It is documented for the sake of completeness. +</p></dd></dl> + +<p>A <code>gdb.Frame</code> object has the following methods: +</p> +<dl> +<dt><a name="index-Frame_002eis_005fvalid"></a>Function: <strong>Frame.is_valid</strong> <em>()</em></dt> +<dd><p>Returns true if the <code>gdb.Frame</code> object is valid, false if not. +A frame object can become invalid if the frame it refers to doesn’t +exist anymore in the inferior. All <code>gdb.Frame</code> methods will throw +an exception if it is invalid at the time the method is called. +</p></dd></dl> + +<dl> +<dt><a name="index-Frame_002ename"></a>Function: <strong>Frame.name</strong> <em>()</em></dt> +<dd><p>Returns the function name of the frame, or <code>None</code> if it can’t be +obtained. +</p></dd></dl> + +<dl> +<dt><a name="index-Frame_002earchitecture"></a>Function: <strong>Frame.architecture</strong> <em>()</em></dt> +<dd><p>Returns the <code>gdb.Architecture</code> object corresponding to the frame’s +architecture. See <a href="Architectures-In-Python.html#Architectures-In-Python">Architectures In Python</a>. +</p></dd></dl> + +<dl> +<dt><a name="index-Frame_002etype"></a>Function: <strong>Frame.type</strong> <em>()</em></dt> +<dd><p>Returns the type of the frame. The value can be one of: +</p><dl compact="compact"> +<dt><code>gdb.NORMAL_FRAME</code></dt> +<dd><p>An ordinary stack frame. +</p> +</dd> +<dt><code>gdb.DUMMY_FRAME</code></dt> +<dd><p>A fake stack frame that was created by <small>GDB</small> when performing an +inferior function call. +</p> +</dd> +<dt><code>gdb.INLINE_FRAME</code></dt> +<dd><p>A frame representing an inlined function. The function was inlined +into a <code>gdb.NORMAL_FRAME</code> that is older than this one. +</p> +</dd> +<dt><code>gdb.TAILCALL_FRAME</code></dt> +<dd><p>A frame representing a tail call. See <a href="Tail-Call-Frames.html#Tail-Call-Frames">Tail Call Frames</a>. +</p> +</dd> +<dt><code>gdb.SIGTRAMP_FRAME</code></dt> +<dd><p>A signal trampoline frame. This is the frame created by the OS when +it calls into a signal handler. +</p> +</dd> +<dt><code>gdb.ARCH_FRAME</code></dt> +<dd><p>A fake stack frame representing a cross-architecture call. +</p> +</dd> +<dt><code>gdb.SENTINEL_FRAME</code></dt> +<dd><p>This is like <code>gdb.NORMAL_FRAME</code>, but it is only used for the +newest frame. +</p></dd> +</dl> +</dd></dl> + +<dl> +<dt><a name="index-Frame_002eunwind_005fstop_005freason"></a>Function: <strong>Frame.unwind_stop_reason</strong> <em>()</em></dt> +<dd><p>Return an integer representing the reason why it’s not possible to find +more frames toward the outermost frame. Use +<code>gdb.frame_stop_reason_string</code> to convert the value returned by this +function to a string. The value can be one of: +</p> +<dl compact="compact"> +<dt><code>gdb.FRAME_UNWIND_NO_REASON</code></dt> +<dd><p>No particular reason (older frames should be available). +</p> +</dd> +<dt><code>gdb.FRAME_UNWIND_NULL_ID</code></dt> +<dd><p>The previous frame’s analyzer returns an invalid result. This is no +longer used by <small>GDB</small>, and is kept only for backward +compatibility. +</p> +</dd> +<dt><code>gdb.FRAME_UNWIND_OUTERMOST</code></dt> +<dd><p>This frame is the outermost. +</p> +</dd> +<dt><code>gdb.FRAME_UNWIND_UNAVAILABLE</code></dt> +<dd><p>Cannot unwind further, because that would require knowing the +values of registers or memory that have not been collected. +</p> +</dd> +<dt><code>gdb.FRAME_UNWIND_INNER_ID</code></dt> +<dd><p>This frame ID looks like it ought to belong to a NEXT frame, +but we got it for a PREV frame. Normally, this is a sign of +unwinder failure. It could also indicate stack corruption. +</p> +</dd> +<dt><code>gdb.FRAME_UNWIND_SAME_ID</code></dt> +<dd><p>This frame has the same ID as the previous one. That means +that unwinding further would almost certainly give us another +frame with exactly the same ID, so break the chain. Normally, +this is a sign of unwinder failure. It could also indicate +stack corruption. +</p> +</dd> +<dt><code>gdb.FRAME_UNWIND_NO_SAVED_PC</code></dt> +<dd><p>The frame unwinder did not find any saved PC, but we needed +one to unwind further. +</p> +</dd> +<dt><code>gdb.FRAME_UNWIND_MEMORY_ERROR</code></dt> +<dd><p>The frame unwinder caused an error while trying to access memory. +</p> +</dd> +<dt><code>gdb.FRAME_UNWIND_FIRST_ERROR</code></dt> +<dd><p>Any stop reason greater or equal to this value indicates some kind +of error. This special value facilitates writing code that tests +for errors in unwinding in a way that will work correctly even if +the list of the other values is modified in future <small>GDB</small> +versions. Using it, you could write: +</p><div class="smallexample"> +<pre class="smallexample">reason = gdb.selected_frame().unwind_stop_reason () +reason_str = gdb.frame_stop_reason_string (reason) +if reason >= gdb.FRAME_UNWIND_FIRST_ERROR: + print ("An error occured: %s" % reason_str) +</pre></div> +</dd> +</dl> + +</dd></dl> + +<dl> +<dt><a name="index-Frame_002epc"></a>Function: <strong>Frame.pc</strong> <em>()</em></dt> +<dd><p>Returns the frame’s resume address. +</p></dd></dl> + +<dl> +<dt><a name="index-Frame_002eblock"></a>Function: <strong>Frame.block</strong> <em>()</em></dt> +<dd><p>Return the frame’s code block. See <a href="Blocks-In-Python.html#Blocks-In-Python">Blocks In Python</a>. If the frame +does not have a block – for example, if there is no debugging +information for the code in question – then this will throw an +exception. +</p></dd></dl> + +<dl> +<dt><a name="index-Frame_002efunction"></a>Function: <strong>Frame.function</strong> <em>()</em></dt> +<dd><p>Return the symbol for the function corresponding to this frame. +See <a href="Symbols-In-Python.html#Symbols-In-Python">Symbols In Python</a>. +</p></dd></dl> + +<dl> +<dt><a name="index-Frame_002eolder"></a>Function: <strong>Frame.older</strong> <em>()</em></dt> +<dd><p>Return the frame that called this frame. +</p></dd></dl> + +<dl> +<dt><a name="index-Frame_002enewer"></a>Function: <strong>Frame.newer</strong> <em>()</em></dt> +<dd><p>Return the frame called by this frame. +</p></dd></dl> + +<dl> +<dt><a name="index-Frame_002efind_005fsal"></a>Function: <strong>Frame.find_sal</strong> <em>()</em></dt> +<dd><p>Return the frame’s symtab and line object. +See <a href="Symbol-Tables-In-Python.html#Symbol-Tables-In-Python">Symbol Tables In Python</a>. +</p></dd></dl> + +<a name="gdbpy_005fframe_005fread_005fregister"></a><dl> +<dt><a name="index-Frame_002eread_005fregister"></a>Function: <strong>Frame.read_register</strong> <em>(register)</em></dt> +<dd><p>Return the value of <var>register</var> in this frame. Returns a +<code>Gdb.Value</code> object. Throws an exception if <var>register</var> does +not exist. The <var>register</var> argument must be one of the following: +</p><ol> +<li> A string that is the name of a valid register (e.g., <code>'sp'</code> or +<code>'rax'</code>). +</li><li> A <code>gdb.RegisterDescriptor</code> object (see <a href="Registers-In-Python.html#Registers-In-Python">Registers In Python</a>). +</li><li> A <small>GDB</small> internal, platform specific number. Using these +numbers is supported for historic reasons, but is not recommended as +future changes to <small>GDB</small> could change the mapping between +numbers and the registers they represent, breaking any Python code +that uses the platform-specific numbers. The numbers are usually +found in the corresponding <samp><var>platform</var>-tdep.h</samp> file in the +<small>GDB</small> source tree. +</li></ol> +<p>Using a string to access registers will be slightly slower than the +other two methods as <small>GDB</small> must look up the mapping between +name and internal register number. If performance is critical +consider looking up and caching a <code>gdb.RegisterDescriptor</code> +object. +</p></dd></dl> + +<dl> +<dt><a name="index-Frame_002eread_005fvar"></a>Function: <strong>Frame.read_var</strong> <em>(variable <span class="roman">[</span>, block<span class="roman">]</span>)</em></dt> +<dd><p>Return the value of <var>variable</var> in this frame. If the optional +argument <var>block</var> is provided, search for the variable from that +block; otherwise start at the frame’s current block (which is +determined by the frame’s current program counter). The <var>variable</var> +argument must be a string or a <code>gdb.Symbol</code> object; <var>block</var> must be a +<code>gdb.Block</code> object. +</p></dd></dl> + +<dl> +<dt><a name="index-Frame_002eselect"></a>Function: <strong>Frame.select</strong> <em>()</em></dt> +<dd><p>Set this frame to be the selected frame. See <a href="Stack.html#Stack">Examining the +Stack</a>. +</p></dd></dl> + +<dl> +<dt><a name="index-Frame_002elevel"></a>Function: <strong>Frame.level</strong> <em>()</em></dt> +<dd><p>Return an integer, the stack frame level for this frame. See <a href="Frames.html#Frames">Stack Frames</a>. +</p></dd></dl> + +<dl> +<dt><a name="index-Frame_002elanguage"></a>Function: <strong>Frame.language</strong> <em>()</em></dt> +<dd><p>Return a string, the source language for this frame. +</p></dd></dl> + +<hr> +<div class="header"> +<p> +Next: <a href="Blocks-In-Python.html#Blocks-In-Python" accesskey="n" rel="next">Blocks In Python</a>, Previous: <a href="Objfiles-In-Python.html#Objfiles-In-Python" accesskey="p" rel="previous">Objfiles In Python</a>, Up: <a href="Python-API.html#Python-API" accesskey="u" rel="up">Python API</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> |