BREAKPOINTS PSAM Commands BREAKPOINTS
NAME
breakpoints, clear, disable, enable, status, stop, stopi -
breakpoint commands
SYNOPSIS
breakpoints
clear <breakpoint reference number>
disable <breakpoint reference number>
enable <breakpoint reference number>
status
stop at <line number> [ <command> ]
stop in <FORTRAN-PLUS procedure> [ <command> ]
stopi at <code offset> [ <command> ]
stopi in <APAL procedure> [ <command> ]
DESCRIPTION
Breakpoints allow DAP program execution to be halted at par-
ticular locations. Breakpoints can be inserted into both
FORTRAN-PLUS and APAL code. FORTRAN-PLUS breakpoints are
located by file name and line number or by procedure name.
APAL breakpoints are located by procedure name and offset or
by procedure name alone. Breakpoints can optionally be asso-
ciated with a psam command which, if present, is executed
each time the breakpoint is reached.
One of the options to dapopt, the -b1 option, causes control
to be passed to psam just before the first DAP program
statement is executed. psam enters a mode known as Break-
point Edit Mode in which all commands are available. There-
fore a DAP program containing no pause statements or run-
time errors can be stopped at an arbitrary location without
recompilation.
Setting Breakpoints
FORTRAN-PLUS breakpoints are created by the stop command and
APAL breakpoints by the stopi command. These commands are
described below.
The stop at command sets a breakpoint on the specified line
of the current source file if that line contains executable
FORTRAN-PLUS code.
The stop in command sets a breakpoint on the first execut-
able line of the given FORTRAN-PLUS procedure.
The stopi at command sets a breakpoint at the specified
offset within the currently selected APAL procedure. Offsets
can be given in decimal or hexadecimal, hexadecimal offsets
being preceded by #, 0x or 0X.
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BREAKPOINTS PSAM Commands BREAKPOINTS
The stopi in command sets a breakpoint at offset 0 within
the given APAL procedure.
APAL breakpoints are subject to the restriction there cannot
be breakpoints on both a DO instruction and the last
instruction in the corresponding DO loop at the same time.
The current source file is determined initially by the file
in which execution most recently halted and thereafter by
the file command. The procedure command behaves similarly
for the current procedure. Source line numbers for the
currently selected file and code offsets for the current
procedure can be displayed with the list and code commands
respectively.
FORTRAN-PLUS breakpoints cannot be set on a source line
which does not contain executable code or is a continuation
line; FORTRAN-PLUS breakpoints cannot be set in APAL pro-
cedures and vice-versa; breakpoints cannot be set in AMT-
supplied code; nor can multiple breakpoints be set at the
same location.
Manipulating Breakpoints
Each breakpoint is given a unique reference number which is
displayed when the breakpoint is set. The reference numbers
and other information for all breakpoints can be displayed
using the breakpoints command. Breakpoints can be rendered
inactive with the disable command, re-activated with enable
and deleted with the clear command. The disable, enable and
clear commands manipulate individual breakpoints identified
by reference number, or all breakpoints if the character '*'
is used.
The status command provides a means to create a macro file
which, when executed, will reproduce the current break-
points. The status command takes no arguments and outputs
the psam commands required to duplicate the current break-
points to the standard output stream, which may be
redirected to a file.
EXAMPLES
stop at 10 set breakpoint on line 10 of
current source file.
stop in fred set breakpoint at start of
FORTRAN-PLUS subroutine FRED.
stopi at #1a registers m*
set breakpoint at offset 1a (Hex)
in the current procedure and exe-
cute the command registers m* when
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BREAKPOINTS PSAM Commands BREAKPOINTS
the breakpoint is encountered.
disable 2 disable breakpoint with reference
number 2.
clear * delete all breakpoints.
status > bpmacro1 save current breakpoints to the
macro file bpmacro1.
SEE ALSO
code, file, interpreter, list, macro, procedure
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