[RFA_v4 4/8] Documents the new commands 'frame apply', faas, taas, tfaas

Philippe Waroquiers
2018-07-10T21:39:50Z

Documents the new commands 'frame apply', faas, taas, tfaas.
Documents the new arguments [FLAG]... added to 'thread apply'.

gdb/doc/ChangeLog
2018-07-09 Philippe Waroquiers <philippe.waroquiers@skynet.be>

* gdb.texinfo (Debugging Programs with Multiple Threads):
Document changes to 'thread apply'. Document 'taas'.
Document 'tfaas'.
(Examining the Stack): Document 'frame apply'. Document 'faas'.
---
gdb/doc/gdb.texinfo | 188 +++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 186 insertions(+), 2 deletions(-)

diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index 245d3f1b97..a49ef6cda0 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -2936,7 +2936,7 @@ programs:
@item automatic notification of new threads
@item @samp{thread @var{thread-id}}, a command to switch among threads
@item @samp{info threads}, a command to inquire about existing threads
-@item @samp{thread apply [@var{thread-id-list}] [@var{all}] @var{args}},
+@item @samp{thread apply [@var{thread-id-list} | all] @var{args}},
a command to apply a command to a list of threads
@item thread-specific breakpoints
@item @samp{set print thread-events}, which controls printing of
@@ -3173,7 +3173,7 @@ threads.

@kindex thread apply
@cindex apply command to several threads
-@item thread apply [@var{thread-id-list} | all [-ascending]] @var{command}
+@item thread apply [@var{thread-id-list} | all [-ascending]] [@var{flag}]@dots{} @var{command}
The @code{thread apply} command allows you to apply the named
@var{command} to one or more threads. Specify the threads that you
want affected using the thread ID list syntax (@pxref{thread ID
@@ -3182,6 +3182,59 @@ command to all threads in descending order, type @kbd{thread apply all
@var{command}}. To apply a command to all threads in ascending order,
type @kbd{thread apply all -ascending @var{command}}.

+The @var{flag} arguments control what output to produce and how to handle
+errors raised when applying @var{command} to a thread. @var{flag}
+must start with a @code{-} directly followed by one letter in
+@code{qcs}. If several flags are provided, they must be given
+individually, such as @code{-c -q}.
+
+By default, @value{GDBN} displays some thread information before the
+output produced by @var{command}, and an error raised during the
+execution of a @var{command} will abort @code{thread apply}. The
+following flags can be used to fine-tune this behavior:
+
+@table @code
+@item -c
+The flag @code{-c}, which stands for @samp{continue}, causes any
+errors in @var{command} to be displayed, and the execution of
+@code{thread apply} then continues.
+@item -s
+The flag @code{-s}, which stands for @samp{silent}, causes any errors
+or empty output produced by a @var{command} to be silently ignored.
+That is, the execution continues, but the thread information and errors
+are not printed.
+@item -q
+The flag @code{-q} (@samp{quiet}) disables printing the thread
+information.
+@end table
+
+Flags @code{-c} and @code{-s} cannot be used together.
+
+@kindex taas
+@cindex apply command to all threads (ignoring errors and empty output)
+@item taas @var{command}
+Shortcut for @code{thread apply all -s @var{command}}.
+Applies @var{command} on all threads, ignoring errors and empty output.
+
+@kindex tfaas
+@cindex apply a command to all frames of all threads (ignoring errors and empty output)
+@item tfaas @var{command}
+Shortcut for @code{thread apply all -s frame apply all -s @var{command}}.
+Applies @var{command} on all frames of all threads, ignoring errors
+and empty output. Note that the flag @code{-s} is specified twice:
+The first @code{-s} ensures that @code{thread apply} only shows the thread
+information of the threads for which @code{frame apply} produces
+some output. The second @code{-s} is needed to ensure that @code{frame
+apply} shows the frame information of a frame only if the
+@var{command} successfully produced some output.
+
+It can for example be used to print a local variable or a function
+argument without knowing the thread or frame where this variable or argument
+is, using:
+@smallexample
+(@value{GDBP}) tfaas p some_local_var_i_do_not_remember_where_it_is
+@end smallexample
+

@kindex thread name
@cindex name a thread
@@ -7304,6 +7357,7 @@ currently executing frame and describes it briefly, similar to the
* Backtrace:: Backtraces
* Selection:: Selecting a frame
* Frame Info:: Information on a frame
+* Frame Apply:: Applying a command to several frames
* Frame Filter Management:: Managing frame filters

@end menu
@@ -7716,6 +7770,136 @@ accessible at the point of execution of the selected frame.

@end table

+@node Frame Apply
+@section Applying a Command to Several Frames.
+@kindex frame apply
+@cindex apply command to several frames
+@table @code
+@item frame apply [all | @var{count} | @var{-count} | level @var{level}@dots{}] [@var{flag}]@dots{} @var{command}
+The @code{frame apply} command allows you to apply the named
+@var{command} to one or more frames.
+
+@table @code
+@item @code{all}
+Specify @code{all} to apply @var{command} to all frames.
+
+@item @var{count}
+Use @var{count} to apply @var{command} to the innermost @var{count}
+frames, where @var{count} is a positive number.
+
+@item @var{-count}
+Use @var{-count} to apply @var{command} to the outermost @var{count}
+frames, where @var{count} is a positive number.
+
+@item @code{level}
+Use @code{level} to apply @var{command} to the set of frames identified
+by the @var{level} list. @var{level} is a frame level or a range of frame
+levels as @var{level1}-@var{level2}. The frame level is the number shown
+in the first field of the @samp{backtrace} command output.
+E.g., @samp{2-4 6-8 3} indicates to apply @var{command} for the frames
+at levels 2, 3, 4, 6, 7, 8, and then again on frame at level 3.
+
+@end table
+
+@end table
+
+Note that the frames on which @code{frame apply} applies a command are
+also influenced by the @code{set backtrace} settings such as @code{set
+backtrace past-main} and @code{set backtrace limit N}. See
+@xref{Backtrace,,Backtraces}.
+
+The @var{flag} arguments control what output to produce and how to handle
+errors raised when applying @var{command} to a frame. @var{flag}
+must start with a @code{-} directly followed by one letter in
+@code{qcs}. If several flags are provided, they must be given
+individually, such as @code{-c -q}.
+
+By default, @value{GDBN} displays some frame information before the
+output produced by @var{command}, and an error raised during the
+execution of a @var{command} will abort @code{frame apply}. The
+following flags can be used to fine-tune this behavior:
+
+@table @code
+@item -c
+The flag @code{-c}, which stands for @samp{continue}, causes any
+errors in @var{command} to be displayed, and the execution of
+@code{frame apply} then continues.
+@item -s
+The flag @code{-s}, which stands for @samp{silent}, causes any errors
+or empty output produced by a @var{command} to be silently ignored.
+That is, the execution continues, but the frame information and errors
+are not printed.
+@item -q
+The flag @code{-q} (@samp{quiet}) disables printing the frame
+information.
+@end table
+
+The following example shows how the flags @code{-c} and @code{-s} are
+working when applying the command @code{p j} to all frames, where
+variable @code{j} can only be successfully printed in the outermost
+@code{#1 main} frame.
+
+@smallexample
+@group
+(gdb) frame apply all p j
+#0 some_function (i=5) at fun.c:4
+No symbol "j" in current context.
+(gdb) frame apply all -c p j
+#0 some_function (i=5) at fun.c:4
+No symbol "j" in current context.
+#1 0x565555fb in main (argc=1, argv=0xffffd2c4) at fun.c:11
+$1 = 5
+(gdb) frame apply all -s p j
+#1 0x565555fb in main (argc=1, argv=0xffffd2c4) at fun.c:11
+$2 = 5
+(gdb)
+@end group
+@end smallexample
+
+By default, @samp{frame apply}, prints the frame location
+information before the command output:
+
+@smallexample
+@group
+(gdb) frame apply all p $sp
+#0 some_function (i=5) at fun.c:4
+$4 = (void *) 0xffffd1e0
+#1 0x565555fb in main (argc=1, argv=0xffffd2c4) at fun.c:11
+$5 = (void *) 0xffffd1f0
+(gdb)
+@end group
+@end smallexample
+
+If flag @code{-q} is given, no frame information is printed:
+@smallexample
+@group
+(gdb) frame apply all -q p $sp
+$12 = (void *) 0xffffd1e0
+$13 = (void *) 0xffffd1f0
+(gdb)
+@end group
+@end smallexample
+
+@table @code
+
+@kindex faas
+@cindex apply a command to all frames (ignoring errors and empty output)
+@item faas @var{command}
+Shortcut for @code{frame apply all -s @var{command}}.
+Applies @var{command} on all frames, ignoring errors and empty output.
+
+It can for example be used to print a local variable or a function
+argument without knowing the frame where this variable or argument
+is, using:
+@smallexample
+(@value{GDBP}) faas p some_local_var_i_do_not_remember_where_it_is
+@end smallexample
+
+Note that the command @code{tfaas @var{command}} applies @var{command}
+on all frames of all threads. See @xref{Threads,,Threads}.
+@end table
+
+
@node Frame Filter Management
@section Management of Frame Filters.
@cindex managing frame filters
--
2.18.0