| <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> |
| <html> |
| <!-- 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 "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 5.2, http://www.gnu.org/software/texinfo/ --> |
| <head> |
| <title>Debugging with GDB: dotdebug_gdb_scripts section</title> |
| |
| <meta name="description" content="Debugging with GDB: dotdebug_gdb_scripts section"> |
| <meta name="keywords" content="Debugging with GDB: dotdebug_gdb_scripts section"> |
| <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="Auto_002dloading-extensions.html#Auto_002dloading-extensions" rel="up" title="Auto-loading extensions"> |
| <link href="Which-flavor-to-choose_003f.html#Which-flavor-to-choose_003f" rel="next" title="Which flavor to choose?"> |
| <link href="objfile_002dgdbdotext-file.html#objfile_002dgdbdotext-file" rel="prev" title="objfile-gdbdotext file"> |
| <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="dotdebug_005fgdb_005fscripts-section"></a> |
| <div class="header"> |
| <p> |
| Next: <a href="Which-flavor-to-choose_003f.html#Which-flavor-to-choose_003f" accesskey="n" rel="next">Which flavor to choose?</a>, Previous: <a href="objfile_002dgdbdotext-file.html#objfile_002dgdbdotext-file" accesskey="p" rel="prev">objfile-gdbdotext file</a>, Up: <a href="Auto_002dloading-extensions.html#Auto_002dloading-extensions" accesskey="u" rel="up">Auto-loading extensions</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="The-_002edebug_005fgdb_005fscripts-section"></a> |
| <h4 class="subsection">23.4.2 The <code>.debug_gdb_scripts</code> section</h4> |
| <a name="index-_002edebug_005fgdb_005fscripts-section"></a> |
| |
| <p>For systems using file formats like ELF and COFF, |
| when <small>GDB</small> loads a new object file |
| it will look for a special section named <code>.debug_gdb_scripts</code>. |
| If this section exists, its contents is a list of null-terminated entries |
| specifying scripts to load. Each entry begins with a non-null prefix byte that |
| specifies the kind of entry, typically the extension language and whether the |
| script is in a file or inlined in <code>.debug_gdb_scripts</code>. |
| </p> |
| <p>The following entries are supported: |
| </p> |
| <dl compact="compact"> |
| <dt><code>SECTION_SCRIPT_ID_PYTHON_FILE = 1</code></dt> |
| <dt><code>SECTION_SCRIPT_ID_SCHEME_FILE = 3</code></dt> |
| <dt><code>SECTION_SCRIPT_ID_PYTHON_TEXT = 4</code></dt> |
| <dt><code>SECTION_SCRIPT_ID_SCHEME_TEXT = 6</code></dt> |
| </dl> |
| |
| <a name="Script-File-Entries"></a> |
| <h4 class="subsubsection">23.4.2.1 Script File Entries</h4> |
| |
| <p>If the entry specifies a file, <small>GDB</small> will look for the file first |
| in the current directory and then along the source search path |
| (see <a href="Source-Path.html#Source-Path">Specifying Source Directories</a>), |
| except that <samp>$cdir</samp> is not searched, since the compilation |
| directory is not relevant to scripts. |
| </p> |
| <p>File entries can be placed in section <code>.debug_gdb_scripts</code> with, |
| for example, this GCC macro for Python scripts. |
| </p> |
| <div class="example"> |
| <pre class="example">/* Note: The "MS" section flags are to remove duplicates. */ |
| #define DEFINE_GDB_PY_SCRIPT(script_name) \ |
| asm("\ |
| .pushsection \".debug_gdb_scripts\", \"MS\",@progbits,1\n\ |
| .byte 1 /* Python */\n\ |
| .asciz \"" script_name "\"\n\ |
| .popsection \n\ |
| "); |
| </pre></div> |
| |
| <p>For Guile scripts, replace <code>.byte 1</code> with <code>.byte 3</code>. |
| Then one can reference the macro in a header or source file like this: |
| </p> |
| <div class="example"> |
| <pre class="example">DEFINE_GDB_PY_SCRIPT ("my-app-scripts.py") |
| </pre></div> |
| |
| <p>The script name may include directories if desired. |
| </p> |
| <p>Note that loading of this script file also requires accordingly configured |
| <code>auto-load safe-path</code> (see <a href="Auto_002dloading-safe-path.html#Auto_002dloading-safe-path">Auto-loading safe path</a>). |
| </p> |
| <p>If the macro invocation is put in a header, any application or library |
| using this header will get a reference to the specified script, |
| and with the use of <code>"MS"</code> attributes on the section, the linker |
| will remove duplicates. |
| </p> |
| <a name="Script-Text-Entries"></a> |
| <h4 class="subsubsection">23.4.2.2 Script Text Entries</h4> |
| |
| <p>Script text entries allow to put the executable script in the entry |
| itself instead of loading it from a file. |
| The first line of the entry, everything after the prefix byte and up to |
| the first newline (<code>0xa</code>) character, is the script name, and must not |
| contain any kind of space character, e.g., spaces or tabs. |
| The rest of the entry, up to the trailing null byte, is the script to |
| execute in the specified language. The name needs to be unique among |
| all script names, as <small>GDB</small> executes each script only once based |
| on its name. |
| </p> |
| <p>Here is an example from file <samp>py-section-script.c</samp> in the <small>GDB</small> |
| testsuite. |
| </p> |
| <div class="example"> |
| <pre class="example">#include "symcat.h" |
| #include "gdb/section-scripts.h" |
| asm( |
| ".pushsection \".debug_gdb_scripts\", \"MS\",@progbits,1\n" |
| ".byte " XSTRING (SECTION_SCRIPT_ID_PYTHON_TEXT) "\n" |
| ".ascii \"gdb.inlined-script\\n\"\n" |
| ".ascii \"class test_cmd (gdb.Command):\\n\"\n" |
| ".ascii \" def __init__ (self):\\n\"\n" |
| ".ascii \" super (test_cmd, self).__init__ (" |
| "\\\"test-cmd\\\", gdb.COMMAND_OBSCURE)\\n\"\n" |
| ".ascii \" def invoke (self, arg, from_tty):\\n\"\n" |
| ".ascii \" print (\\\"test-cmd output, arg = %s\\\" % arg)\\n\"\n" |
| ".ascii \"test_cmd ()\\n\"\n" |
| ".byte 0\n" |
| ".popsection\n" |
| ); |
| </pre></div> |
| |
| <p>Loading of inlined scripts requires a properly configured |
| <code>auto-load safe-path</code> (see <a href="Auto_002dloading-safe-path.html#Auto_002dloading-safe-path">Auto-loading safe path</a>). |
| The path to specify in <code>auto-load safe-path</code> is the path of the file |
| containing the <code>.debug_gdb_scripts</code> section. |
| </p> |
| <hr> |
| <div class="header"> |
| <p> |
| Next: <a href="Which-flavor-to-choose_003f.html#Which-flavor-to-choose_003f" accesskey="n" rel="next">Which flavor to choose?</a>, Previous: <a href="objfile_002dgdbdotext-file.html#objfile_002dgdbdotext-file" accesskey="p" rel="prev">objfile-gdbdotext file</a>, Up: <a href="Auto_002dloading-extensions.html#Auto_002dloading-extensions" accesskey="u" rel="up">Auto-loading extensions</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> |
