Tornado

7
Debugger
and rev, discussed already in What Code to Display, p.254. The following commands
are also especially useful because of CrossWind graphical extensions:
display /W expr
The and buttons provide a convenient way to generate active displays
of symbol and pointer values, allowing you to monitor important data as your
application executes under debugger control. However, sometimes the most
useful data to monitor is the result of an expression—something that does not
appear in your program, and hence cannot be selected before clicking a button.
In this situation, you can use the CrossWind /W format with the GDB display
command to request an inspection window from the command panel. Because
you type the expression argument directly, you can use any source-language
expression to specify the value to monitor. An inspection window appears,
which behaves just like those generated with buttons (CrossWind Buttons,
p.244).
frame n
Displays a summary of a stack frame, in the command panel. But it also has a
useful side effect: it re-displays the code in the program-display panel,
centered around the line of code corresponding to that stack frame.
Used without any arguments, this command provides a quick way of restoring
the program-display panel context for the current stack frame, after you scroll
to inspect some other region of code. Used with an argument n (a stack-frame
number, or a stack-frame address), this command provides a quick way of
looking at the source-code context elsewhere in the calling stack. For more
information about stack frames in GDB and about the GDB frame command,
see GDB User’s Guide: Examining the Stack.
7
Managing Targets
Instead of using the Targets menu (CrossWind Menus, p.238), you can select a target
from the command panel with the target wtx command. The two methods of
selecting a target are interchangeable; however, it may sometimes be more
convenient to use the GDB command language—for example, you might specify a
target this way in your .gdbinit initialization file or in other debugger scripts.
target wtx servername
Connects to a target managed by the target server registered as servername in
the Tornado registry, using the WTX protocol. Use this command regardless of
whether your target is attached through a serial line or through an Ethernet
connection; the target server subsumes such communication details. (See
257