Debug Manual

Debug Commands
Debug Manual—421921-003
4-69
T Command
[OUT] output-dev
specifies where the display is directed. Debug output can be directed to an output
device, a process, or a spooler collector. Debug output cannot be directed to a disk
file. If you omit output-dev, Debug assumes the home terminal.
The output-dev parameter has these formats.
Syntax for a device other than a disk:
[ node.]{device-name[.qualifier ] }
{ldev-number }
Syntax for a named process:
[ node.]process-name[:seq-no][.qual-1[.qual-2] ]
[ node.]$:cpu:pin:seq-no
For syntax descriptions of these process and device names, see the Guardian
Procedure Calls Reference Manual.
Considerations
•
If the process being debugged contains threads, Debug displays a stack trace for
only the thread currently in effect.
•
If the name you specify for output-dev happens to match a register name, a
syntax error might result. To avoid any possibility of ambiguity, include the keyword
OUT before output-dev, which informs Debug that the name refers to an output
device. For example, suppose a printer is named $S1, which is also the name of a
TNS/R register. Specifying OUT $S1 on the T command tells Debug that $S1 is an
output device.
•
In a stack trace displayed by the T command, the top line represents the most
recently called procedure, the second line represents the next most recently called
procedure, and so on. For example, in the following trace, PROMPT called
CHECKRECEIVE.
%004251: %002223 E=%000000 L=%004072 CHECKRECEIVE + %000250
%004070: %006163 E=%000000 L=%003634 PROMPT + %001064
•
There are two ways to start a stack trace at a particular stack frame in native
mode. One way is to indicate where the frame is and which procedure built the
frame. Do this by including the appropriate register = expression
specifications in the T command. For example:
T$RA 0x70302304, $30 0xFFFFFFFF
An alternate and easier way is to examine the stack for a value that is likely to be a
RISC PC address (that is, a value that addresses the SCr, SLr, UCr, or SRL code
space) and provide the address of that value as the expression for the AT
parameter.