Introduction › Debugging Process › Runtime Phase

Runtime Phase

DEBUG and EXIT Required

The runtime phase of the debugging process takes place during the execution of a program. Debugging cannot occur during runtime unless:

• You have used the DEBUG command during the setup phase to define the program to the debugger
• You have used the EXIT command, which retains the debugger control blocks, when leaving the setup phase

What Happens at the Breakpoint

When you have defined a program to the debugger, the program task code invokes both the runtime phase of the debugger and the execution of the program. At a breakpoint, the DC/UCF runtime system suspends program execution, and you gain control under the debugger. A message is displayed that signals the breakpoint interrupt and describes its location.

Three Breakpoint Display Formats

For example, assume that a program called TESTPROG is defined to the debugger and a breakpoint is established like this during the setup phase:

DEBUG >
at @00bf080

The debugger verifies the establishment of the breakpoint:

AT @00BF080
AT > @00BF080 ADDED
DEBUG >

When this breakpoint is encountered during runtime, the debugger identifies the address, the program, and the debug expression that established the breakpoint:

AT OFFSET @80 IN TESTPROG EXPRESSION @00BF080
DEBUG >

In response to the DEBUG> prompt, you can make additional queries or perform other debugging activities.