System Debug Reference Manual (32650-90888)

Chapter 4 89

System Debug Command Speciﬁcations :-Exit

B (break)

PROCESSSTUDENT. The expression evaluator found the procedure in the program ﬁle in

logical segment zero, at an offset of %1665 CM words from the start of the segment

procedure.

%cmdebug > b 0.1670

added: CM [2] PROG % 0.1670 PROCESSSTUDENT+%263

Set a breakpoint %1670 CM words into the program ﬁle's logical segment zero. That

address corresponds to the %263rd CM word from the start of the PROCESSSTUDENT

procedure. Note that this command sets a breakpoint in the program ﬁle, no matter where

the process was stopped (in the group library for example), since the B command implies

the program ﬁle.

%cmdebug > b 1672

added: CM [3] PROG % 0.1672 PROCESSSTUDENT+%265

Set a breakpoint %1672 CM words into the program ﬁle. The logical segment number from

the current value of CMPC is used as the segment number for this command.

%cmdebug > b processstudent+14

added: CM [4] PROG % 0.1421 PROCESSSTUDENT+%14

Set a breakpoint %14 CM words into the start of the procedure PROCESSSTUDENT. This

address corresponds to the ﬁrst statement of the nested procedure HIGHSCORE which is

contained in the level 1 procedure PROCESSSTUDENT. The correct offset to use for nested

procedures is determined by looking at the statement map produced by the Pascal

compiler. (All language compilers produce similar maps.) Unfortunately, information about

nested procedure names and size is not available for CM programs.

%cmdebug > b ob'+40,-3

added: CM T|5| PROG % 0.40 OB'+%40

Set a breakpoint %40 words into the procedure ob' (the outer block of the Pascal program

being run). The third time the breakpoint is encountered, stop in Debug and delete the

breakpoint. The notation T|5| indicates a temporary breakpoint with index number 2. The

vertical bars indicate that the process does not stop the next time the breakpoint is

encountered, since the count is not yet exhausted.

%cmdebug > b ?average

added: CM [6] GRP % 0.13 ?AVERAGE

%cmdebug > bg ?average+4

added: CM [7] GRP % 0.17 AVERAGE+%17

%cmdebug > b grp(0.20)

added: CM [10] GRP % 0.20 AVERAGE+%20

Set a breakpoint at the entry point to the procedure average. Notice that the procedure

was found in the group (GRP) library. The B command starts searching for symbol names in

the program ﬁle and continues through all of the loaded library ﬁles until a match is found.

The second example uses the BG command to explicitly restrict the search for symbol

names to the group library. The third example shows how the coercion function GRP is used

to specify a logical segment in the group library rather than the program ﬁle.

%cmdebug > bs ?fwrite,#100,q,{wl "Another #100 records written";c}