From 5b860c93e3c659625d92a2d2247712a84eac1041 Mon Sep 17 00:00:00 2001 From: Philippe Waroquiers Date: Tue, 25 Jun 2019 00:50:29 +0200 Subject: [PATCH] NEWS and documentation for alias default-args related concept and commands. gdb/ChangeLog 2020-06-22 Philippe Waroquiers * NEWS: Mention change to the alias command. gdb/doc/ChangeLog 2020-06-22 Philippe Waroquiers * gdb.texinfo (Command aliases default args): New node documenting how to use default args for a command using aliases. (Aliases): Document the new 'DEFAULT-ARGS...' option. (Help): Update help aliases text and describe when full alias definition is provided. --- gdb/ChangeLog | 4 ++ gdb/NEWS | 15 ++++++ gdb/doc/ChangeLog | 8 +++ gdb/doc/gdb.texinfo | 118 +++++++++++++++++++++++++++++++++++++++++--- 4 files changed, 139 insertions(+), 6 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 675a9e4ce8..a83f5afdcd 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,7 @@ +2020-06-22 Philippe Waroquiers + + * NEWS: Mention change to the alias command. + 2020-06-22 Philippe Waroquiers * cli/cli-cmds.c (lookup_cmd_for_default_args) diff --git a/gdb/NEWS b/gdb/NEWS index cebfd18f0c..f7585133c5 100644 --- a/gdb/NEWS +++ b/gdb/NEWS @@ -79,6 +79,21 @@ tui new-layout NAME WINDOW WEIGHT [WINDOW WEIGHT]... Define a new TUI layout, specifying its name and the windows that will be displayed. +* Changed commands + +alias [-a] [--] ALIAS = COMMAND [DEFAULT-ARGS...] + The alias command can now specify default args for an alias. + GDB automatically prepends the alias default args to the argument list + provided explicitly by the user. + For example, to have a backtrace with full details, you can define + an alias 'bt_ALL' as + 'alias bt_ALL = backtrace -entry-values both -frame-arg all + -past-main -past-entry -full'. + Alias default arguments can also use a set of nested 'with' commands, + e.g. 'alias pp10 = with print pretty -- with print elem 10 -- print' + defines the alias pp10 that will pretty print a maximum of 10 elements + of the given expression (if the expression is an array). + * New targets GNU/Linux/RISC-V (gdbserver) riscv*-*-linux* diff --git a/gdb/doc/ChangeLog b/gdb/doc/ChangeLog index 1cb43f7e24..fe6bfe7452 100644 --- a/gdb/doc/ChangeLog +++ b/gdb/doc/ChangeLog @@ -1,3 +1,11 @@ +2020-06-22 Philippe Waroquiers + + * gdb.texinfo (Command aliases default args): New node documenting + how to use default args for a command using aliases. + (Aliases): Document the new 'DEFAULT-ARGS...' option. + (Help): Update help aliases text and describe when full alias + definition is provided. + 2020-06-11 Tom Tromey * gdb.texinfo (Index Files): Reword. Remove Ada limitation. diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo index 59e3e75d18..7f572c37c5 100644 --- a/gdb/doc/gdb.texinfo +++ b/gdb/doc/gdb.texinfo @@ -1577,6 +1577,7 @@ show you the alternatives available, if there is more than one possibility). * Command Settings:: How to change default behavior of commands * Completion:: Command completion * Command Options:: Command options +* Command aliases default args:: Automatically prepend default arguments to user-defined aliases * Help:: How to ask @value{GDBN} for help @end menu @@ -1997,6 +1998,89 @@ uppercase. (For more on using the @code{print} command, see @ref{Data, ,Examining Data}.) +@node Command aliases default args +@section Automatically prepend default arguments to user-defined aliases + +You can tell @value{GDBN} to always prepend some default arguments to +the list of arguments provided explicitly by the user when using a +user-defined alias. + +If you repeatedly use the same arguments or options for a command, you +can define an alias for this command and tell @value{GDBN} to +automatically prepend these arguments or options to the list of +arguments you type explicitly when using the alias@footnote{@value{GDBN} +could easily accept default arguments for pre-defined commands and aliases, +but it was deemed this would be confusing, and so is not allowed.}. + +For example, if you often use the command @code{thread apply all} +specifying to work on the threads in ascending order and to continue in case it +encounters an error, you can tell @value{GDBN} to automatically preprend +the @code{-ascending} and @code{-c} options by using: + +@smallexample +(@value{GDBP}) alias thread apply asc-all = thread apply all -ascending -c +@end smallexample + +Once you have defined this alias with its default args, any time you type +the @code{thread apply asc-all} followed by @code{some arguments}, +@value{GDBN} will execute @code{thread apply all -ascending -c some arguments}. + +To have even less to type, you can also define a one word alias: +@smallexample +(@value{GDBP}) alias t_a_c = thread apply all -ascending -c +@end smallexample + +As usual, unambiguous abbreviations can be used for @var{alias} +and @var{default-args}. + +The different aliases of a command do not share their default args. +For example, you define a new alias @code{bt_ALL} showing all possible +information and another alias @code{bt_SMALL} showing very limited information +using: +@smallexample +(@value{GDBP}) alias bt_ALL = backtrace -entry-values both -frame-arg all \ + -past-main -past-entry -full +(@value{GDBP}) alias bt_SMALL = backtrace -entry-values no -frame-arg none \ + -past-main off -past-entry off +@end smallexample + +(For more on using the @code{alias} command, see @ref{Aliases}.) + +Default args are not limited to the arguments and options of @var{command}, +but can specify nested commands if @var{command} accepts such a nested command +as argument. +For example, the below defines @code{faalocalsoftype} that lists the +frames having locals of a certain type, together with the matching +local vars: +@smallexample +(@value{GDBP}) alias faalocalsoftype = frame apply all info locals -q -t +(@value{GDBP}) faalocalsoftype int +#1 0x55554f5e in sleeper_or_burner (v=0xdf50) at sleepers.c:86 +i = 0 +ret = 21845 +@end smallexample + +This is also very useful to define an alias for a set of nested @code{with} +commands to have a particular combination of temporary settings. For example, +the below defines the alias @code{pp10} that pretty prints an expression +argument, with a maximum of 10 elements if the expression is a string or +an array: +@smallexample +(@value{GDBP}) alias pp10 = with print pretty -- with print elements 10 -- print +@end smallexample +This defines the alias @code{pp10} as being a sequence of 3 commands. +The first part @code{with print pretty --} temporarily activates the setting +@code{set print pretty}, then launches the command that follows the separator +@code{--}. +The command following the first part is also a @code{with} command that +temporarily changes the setting @code{set print elements} to 10, then +launches the command that follows the second separator @code{--}. +The third part @code{print} is the command the @code{pp10} alias will launch, +using the temporary values of the settings and the arguments explicitly given +by the user. +For more information about the @code{with} command usage, +see @ref{Command Settings}. + @node Help @section Getting Help @cindex online documentation @@ -2016,7 +2100,7 @@ display a short list of named classes of commands: (@value{GDBP}) help List of classes of commands: -aliases -- Aliases of other commands +aliases -- User-defined aliases of other commands breakpoints -- Making program stop at certain points data -- Examining data files -- Specifying and examining files @@ -2043,8 +2127,9 @@ Command name abbreviations are allowed if unambiguous. Using one of the general help classes as an argument, you can get a list of the individual commands in that class. If a command has aliases, the aliases are given after the command name, separated by -commas. For example, here is the help display for the class -@code{status}: +commas. If an alias has default arguments, the full definition of +the alias is given after the first line. +For example, here is the help display for the class @code{status}: @smallexample (@value{GDBP}) help status @@ -2056,7 +2141,10 @@ List of commands: @c to fit in smallbook page size. info, inf, i -- Generic command for showing things about the program being debugged -info address -- Describe where symbol SYM is stored. +info address, iamain -- Describe where symbol SYM is stored. + alias iamain = info address main +info all-registers -- List of all registers and their contents, + for selected stack frame. ... show, info set -- Generic command for showing things about the debugger @@ -2072,6 +2160,8 @@ With a command name as @code{help} argument, @value{GDBN} displays a short paragraph on how to use that command. If that command has one or more aliases, @value{GDBN} will display a first line with the command name and all its aliases separated by commas. +This first line will be followed by the full definition of all aliases +having default arguments. @kindex apropos @item apropos [-v] @var{regexp} @@ -2092,7 +2182,7 @@ results in: @smallexample @group alias -- Define a new command that is an alias of an existing command -aliases -- Aliases of other commands +aliases -- User-defined aliases of other commands @end group @end smallexample @@ -27502,7 +27592,7 @@ You can define a new alias with the @samp{alias} command. @table @code @kindex alias -@item alias [-a] [--] @var{ALIAS} = @var{COMMAND} +@item alias [-a] [--] @var{ALIAS} = @var{COMMAND} [DEFAULT-ARGS...] @end table @@ -27513,12 +27603,28 @@ underscores. @var{COMMAND} specifies the name of an existing command that is being aliased. +@var{COMMAND} can also be the name of an existing alias. In this case, +@var{COMMAND} cannot be an alias that has default arguments. + The @samp{-a} option specifies that the new alias is an abbreviation of the command. Abbreviations are not used in command completion. The @samp{--} option specifies the end of options, and is useful when @var{ALIAS} begins with a dash. +You can specify @var{default-args} for your alias. +These @var{default-args} will be automatically added before the alias +arguments typed explicitly on the command line. + +For example, the below defines an alias @code{btfullall} that shows all local +variables and all frame arguments: +@smallexample +(@value{GDBP}) alias btfullall = backtrace -full -frame-arguments all +@end smallexample + +For more information about @var{default-args}, see @ref{Command aliases default args, +,Automatically prepend default arguments to user-defined aliases}. + Here is a simple example showing how to make an abbreviation of a command so that there is less to type. Suppose you were tired of typing @samp{disas}, the current -- 2.34.1