User`s guide

Chapter 6: Controlling Program Execution

Each breakpoint is assigned a number when you create it. Use this number

to reference a breakpoint in the various commands provided for

manipulating breakpoints (for example, disable, enable, and delete, all

described in “Managing Breakpoints, Traces, and Conditional Commands”

on page 70).

Setting Unconditional Breakpoints

To set an unconditional breakpoint, you simply specify the point at which

you want to stop program execution, using one of the following forms of the

stop command:

stop at Sets a breakpoint at the current source line.

stop at line Sets a breakpoint at the speciﬁed source line in the current

source ﬁle.

stop in procedure

Sets a breakpoint to stop execution upon entering the

speciﬁed procedure.

stop at ﬁle:line

Sets a breakpoint in the speciﬁed ﬁle at the speciﬁed line.

Caution: If your program has multiple source ﬁles, be sure to set the

breakpoint in the correct ﬁle. To do so, you can explicitly set the source ﬁle

using dbx’s ﬁle command (see “Changing Source Files” on page 15), or you

can use the func command to go to a source ﬁle containing a speciﬁed

function (see “Moving to a Speciﬁed Procedure” on page 50).

Setting Conditional Breakpoints

An unconditional breakpoint is the simplest type of breakpoint; your

program stops every time it reaches a speciﬁed place. On the other hand, a

conditional breakpoint stops your program only if a condition that you

specify is true. The two conditions that you can test are:

• Has the value of a variable or other memory location changed?

• Is a test expression true?