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diff --git a/share/doc/gdb/Commands-In-Guile.html b/share/doc/gdb/Commands-In-Guile.html new file mode 100644 index 0000000..52cd2f9 --- /dev/null +++ b/share/doc/gdb/Commands-In-Guile.html @@ -0,0 +1,415 @@ +<!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. 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A CLI +command object is created with the <code>make-command</code> Guile function, +and added to <small>GDB</small> with the <code>register-command!</code> Guile function. +This two-step approach is taken to separate out the side-effect of adding +the command to <small>GDB</small> from <code>make-command</code>. +</p> +<p>There is no support for multi-line commands, that is commands that +consist of multiple lines and are terminated with <code>end</code>. +</p> +<dl> +<dt><a name="index-make_002dcommand"></a>Scheme Procedure: <strong>make-command</strong> <em>name <span class="roman">[</span>#:invoke invoke<span class="roman">]</span><!-- /@w --> <span class="roman">[</span><span class="nolinebreak">#:command-class</span> <span class="nolinebreak">command-class</span><span class="roman">]</span><!-- /@w --> <span class="roman">[</span><span class="nolinebreak">#:completer-class</span> completer<span class="roman">]</span><!-- /@w --> <span class="roman">[</span>#:prefix? prefix<span class="roman">]</span><!-- /@w --> <span class="roman">[</span>#:doc <span class="nolinebreak">doc-string</span><span class="roman">]</span><!-- /@w --></em></dt> +<dd> +<p>The argument <var>name</var> is the name of the command. If <var>name</var> consists of +multiple words, then the initial words are looked for as prefix +commands. In this case, if one of the prefix commands does not exist, +an exception is raised. +</p> +<p>The result is the <code><gdb:command></code> object representing the command. +The command is not usable until it has been registered with <small>GDB</small> +with <code>register-command!</code>. +</p> +<p>The rest of the arguments are optional. +</p> +<p>The argument <var>invoke</var> is a procedure of three arguments: <var>self</var>, +<var>args</var> and <var>from-tty</var>. The argument <var>self</var> is the +<code><gdb:command></code> object representing the command. +The argument <var>args</var> is a string representing the arguments passed to +the command, after leading and trailing whitespace has been stripped. +The argument <var>from-tty</var> is a boolean flag and specifies whether the +command should consider itself to have been originated from the user +invoking it interactively. If this function throws an exception, +it is turned into a <small>GDB</small> <code>error</code> call. +Otherwise, the return value is ignored. +</p> +<p>The argument <var>command-class</var> is one of the ‘<samp>COMMAND_</samp>’ constants +defined below. This argument tells <small>GDB</small> how to categorize the +new command in the help system. The default is <code>COMMAND_NONE</code>. +</p> +<p>The argument <var>completer</var> is either <code>#f</code>, one of the ‘<samp>COMPLETE_</samp>’ +constants defined below, or a procedure, also defined below. +This argument tells <small>GDB</small> how to perform completion +for this command. If not provided or if the value is <code>#f</code>, +then no completion is performed on the command. +</p> +<p>The argument <var>prefix</var> is a boolean flag indicating whether the new +command is a prefix command; sub-commands of this command may be +registered. +</p> +<p>The argument <var>doc-string</var> is help text for the new command. +If no documentation string is provided, the default value “This command is +not documented.” is used. +</p></dd></dl> + +<dl> +<dt><a name="index-register_002dcommand_0021"></a>Scheme Procedure: <strong>register-command!</strong> <em>command</em></dt> +<dd><p>Add <var>command</var>, a <code><gdb:command></code> object, to <small>GDB</small>’s +list of commands. +It is an error to register a command more than once. +The result is unspecified. +</p></dd></dl> + +<dl> +<dt><a name="index-command_003f"></a>Scheme Procedure: <strong>command?</strong> <em>object</em></dt> +<dd><p>Return <code>#t</code> if <var>object</var> is a <code><gdb:command></code> object. +Otherwise return <code>#f</code>. +</p></dd></dl> + +<a name="index-don_0027t-repeat-Guile-command"></a> +<dl> +<dt><a name="index-dont_002drepeat"></a>Scheme Procedure: <strong>dont-repeat</strong></dt> +<dd><p>By default, a <small>GDB</small> command is repeated when the user enters a +blank line at the command prompt. A command can suppress this +behavior by invoking the <code>dont-repeat</code> function. This is similar +to the user command <code>dont-repeat</code>, see <a href="Define.html#Define">dont-repeat</a>. +</p></dd></dl> + +<dl> +<dt><a name="index-string_002d_003eargv"></a>Scheme Procedure: <strong>string->argv</strong> <em>string</em></dt> +<dd><p>Convert a string to a list of strings split up according to +<small>GDB</small>’s argv parsing rules. +It is recommended to use this for consistency. +Arguments are separated by spaces and may be quoted. +Example: +</p> +<div class="smallexample"> +<pre class="smallexample">scheme@(guile-user)> (string->argv "1 2\\ \\\"3 '4 \"5' \"6 '7\"") +$1 = ("1" "2 \"3" "4 \"5" "6 '7") +</pre></div> +</dd></dl> + +<dl> +<dt><a name="index-throw_002duser_002derror"></a>Scheme Procedure: <strong>throw-user-error</strong> <em>message . args</em></dt> +<dd><p>Throw a <code>gdb:user-error</code> exception. +The argument <var>message</var> is the error message as a format string, like the +<var>fmt</var> argument to the <code>format</code> Scheme function. +See <a href="http://www.gnu.org/software/guile/manual/html_node/Formatted-Output.html#Formatted-Output">Formatted Output</a> in <cite>GNU Guile Reference Manual</cite>. +The argument <var>args</var> is a list of the optional arguments of <var>message</var>. +</p> +<p>This is used when the command detects a user error of some kind, +say a bad command argument. +</p> +<div class="smallexample"> +<pre class="smallexample">(gdb) guile (use-modules (gdb)) +(gdb) guile +(register-command! (make-command "test-user-error" + #:command-class COMMAND_OBSCURE + #:invoke (lambda (self arg from-tty) + (throw-user-error "Bad argument ~a" arg)))) +end +(gdb) test-user-error ugh +ERROR: Bad argument ugh +</pre></div> +</dd></dl> + +<a name="index-completion-of-Guile-commands"></a> +<dl> +<dt><a name="index-self"></a>completer: <strong>self</strong> <em>text word</em></dt> +<dd><p>If the <var>completer</var> option to <code>make-command</code> is a procedure, +it takes three arguments: <var>self</var> which is the <code><gdb:command></code> +object, and <var>text</var> and <var>word</var> which are both strings. +The argument <var>text</var> holds the complete command line up to the cursor’s +location. The argument <var>word</var> holds the last word of the command line; +this is computed using a word-breaking heuristic. +</p> +<p>All forms of completion are handled by this function, that is, +the <tt class="key">TAB</tt> and <tt class="key">M-?</tt> key bindings (see <a href="Completion.html#Completion">Completion</a>), +and the <code>complete</code> command (see <a href="Help.html#Help">complete</a>). +</p> +<p>This procedure can return several kinds of values: +</p> +<ul> +<li> If the return value is a list, the contents of the list are used as the +completions. It is up to <var>completer</var> to ensure that the +contents actually do complete the word. An empty list is +allowed, it means that there were no completions available. Only +string elements of the list are used; other elements in the +list are ignored. + +</li><li> If the return value is a <code><gdb:iterator></code> object, it is iterated over to +obtain the completions. It is up to <code>completer-procedure</code> to ensure +that the results actually do complete the word. Only +string elements of the result are used; other elements in the +sequence are ignored. + +</li><li> All other results are treated as though there were no available +completions. +</li></ul> +</dd></dl> + +<p>When a new command is registered, it will have been declared as a member of +some general class of commands. This is used to classify top-level +commands in the on-line help system; note that prefix commands are not +listed under their own category but rather that of their top-level +command. The available classifications are represented by constants +defined in the <code>gdb</code> module: +</p> +<dl compact="compact"> +<dt><code>COMMAND_NONE</code> +<a name="index-COMMAND_005fNONE-1"></a> +</dt> +<dd><p>The command does not belong to any particular class. A command in +this category will not be displayed in any of the help categories. +This is the default. +</p> +</dd> +<dt><code>COMMAND_RUNNING</code> +<a name="index-COMMAND_005fRUNNING-1"></a> +</dt> +<dd><p>The command is related to running the inferior. For example, +<code>start</code>, <code>step</code>, and <code>continue</code> are in this category. +Type <kbd>help running</kbd> at the <small>GDB</small> prompt to see a list of +commands in this category. +</p> +</dd> +<dt><code>COMMAND_DATA</code> +<a name="index-COMMAND_005fDATA-1"></a> +</dt> +<dd><p>The command is related to data or variables. For example, +<code>call</code>, <code>find</code>, and <code>print</code> are in this category. Type +<kbd>help data</kbd> at the <small>GDB</small> prompt to see a list of commands +in this category. +</p> +</dd> +<dt><code>COMMAND_STACK</code> +<a name="index-COMMAND_005fSTACK-1"></a> +</dt> +<dd><p>The command has to do with manipulation of the stack. For example, +<code>backtrace</code>, <code>frame</code>, and <code>return</code> are in this +category. Type <kbd>help stack</kbd> at the <small>GDB</small> prompt to see a +list of commands in this category. +</p> +</dd> +<dt><code>COMMAND_FILES</code> +<a name="index-COMMAND_005fFILES-1"></a> +</dt> +<dd><p>This class is used for file-related commands. For example, +<code>file</code>, <code>list</code> and <code>section</code> are in this category. +Type <kbd>help files</kbd> at the <small>GDB</small> prompt to see a list of +commands in this category. +</p> +</dd> +<dt><code>COMMAND_SUPPORT</code> +<a name="index-COMMAND_005fSUPPORT-1"></a> +</dt> +<dd><p>This should be used for “support facilities”, generally meaning +things that are useful to the user when interacting with <small>GDB</small>, +but not related to the state of the inferior. For example, +<code>help</code>, <code>make</code>, and <code>shell</code> are in this category. Type +<kbd>help support</kbd> at the <small>GDB</small> prompt to see a list of +commands in this category. +</p> +</dd> +<dt><code>COMMAND_STATUS</code> +<a name="index-COMMAND_005fSTATUS-1"></a> +</dt> +<dd><p>The command is an ‘<samp>info</samp>’-related command, that is, related to the +state of <small>GDB</small> itself. For example, <code>info</code>, <code>macro</code>, +and <code>show</code> are in this category. Type <kbd>help status</kbd> at the +<small>GDB</small> prompt to see a list of commands in this category. +</p> +</dd> +<dt><code>COMMAND_BREAKPOINTS</code> +<a name="index-COMMAND_005fBREAKPOINTS-1"></a> +</dt> +<dd><p>The command has to do with breakpoints. For example, <code>break</code>, +<code>clear</code>, and <code>delete</code> are in this category. Type <kbd>help +breakpoints</kbd> at the <small>GDB</small> prompt to see a list of commands in +this category. +</p> +</dd> +<dt><code>COMMAND_TRACEPOINTS</code> +<a name="index-COMMAND_005fTRACEPOINTS-1"></a> +</dt> +<dd><p>The command has to do with tracepoints. For example, <code>trace</code>, +<code>actions</code>, and <code>tfind</code> are in this category. Type +<kbd>help tracepoints</kbd> at the <small>GDB</small> prompt to see a list of +commands in this category. +</p> +</dd> +<dt><code>COMMAND_USER</code> +<a name="index-COMMAND_005fUSER-1"></a> +</dt> +<dd><p>The command is a general purpose command for the user, and typically +does not fit in one of the other categories. +Type <kbd>help user-defined</kbd> at the <small>GDB</small> prompt to see +a list of commands in this category, as well as the list of gdb macros +(see <a href="Sequences.html#Sequences">Sequences</a>). +</p> +</dd> +<dt><code>COMMAND_OBSCURE</code> +<a name="index-COMMAND_005fOBSCURE-1"></a> +</dt> +<dd><p>The command is only used in unusual circumstances, or is not of +general interest to users. For example, <code>checkpoint</code>, +<code>fork</code>, and <code>stop</code> are in this category. Type <kbd>help +obscure</kbd> at the <small>GDB</small> prompt to see a list of commands in this +category. +</p> +</dd> +<dt><code>COMMAND_MAINTENANCE</code> +<a name="index-COMMAND_005fMAINTENANCE-1"></a> +</dt> +<dd><p>The command is only useful to <small>GDB</small> maintainers. The +<code>maintenance</code> and <code>flushregs</code> commands are in this category. +Type <kbd>help internals</kbd> at the <small>GDB</small> prompt to see a list of +commands in this category. +</p></dd> +</dl> + +<p>A new command can use a predefined completion function, either by +specifying it via an argument at initialization, or by returning it +from the <code>completer</code> procedure. These predefined completion +constants are all defined in the <code>gdb</code> module: +</p> +<dl compact="compact"> +<dt><code>COMPLETE_NONE</code> +<a name="index-COMPLETE_005fNONE-1"></a> +</dt> +<dd><p>This constant means that no completion should be done. +</p> +</dd> +<dt><code>COMPLETE_FILENAME</code> +<a name="index-COMPLETE_005fFILENAME-1"></a> +</dt> +<dd><p>This constant means that filename completion should be performed. +</p> +</dd> +<dt><code>COMPLETE_LOCATION</code> +<a name="index-COMPLETE_005fLOCATION-1"></a> +</dt> +<dd><p>This constant means that location completion should be done. +See <a href="Location-Specifications.html#Location-Specifications">Location Specifications</a>. +</p> +</dd> +<dt><code>COMPLETE_COMMAND</code> +<a name="index-COMPLETE_005fCOMMAND-1"></a> +</dt> +<dd><p>This constant means that completion should examine <small>GDB</small> +command names. +</p> +</dd> +<dt><code>COMPLETE_SYMBOL</code> +<a name="index-COMPLETE_005fSYMBOL-1"></a> +</dt> +<dd><p>This constant means that completion should be done using symbol names +as the source. +</p> +</dd> +<dt><code>COMPLETE_EXPRESSION</code> +<a name="index-COMPLETE_005fEXPRESSION-1"></a> +</dt> +<dd><p>This constant means that completion should be done on expressions. +Often this means completing on symbol names, but some language +parsers also have support for completing on field names. +</p></dd> +</dl> + +<p>The following code snippet shows how a trivial CLI command can be +implemented in Guile: +</p> +<div class="smallexample"> +<pre class="smallexample">(gdb) guile +(register-command! (make-command "hello-world" + #:command-class COMMAND_USER + #:doc "Greet the whole world." + #:invoke (lambda (self args from-tty) (display "Hello, World!\n")))) +end +(gdb) hello-world +Hello, World! +</pre></div> + +<hr> +<div class="header"> +<p> +Next: <a href="Parameters-In-Guile.html#Parameters-In-Guile" accesskey="n" rel="next">Parameters In Guile</a>, Previous: <a href="Writing-a-Guile-Pretty_002dPrinter.html#Writing-a-Guile-Pretty_002dPrinter" accesskey="p" rel="previous">Writing a Guile Pretty-Printer</a>, Up: <a href="Guile-API.html#Guile-API" accesskey="u" rel="up">Guile 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> |